4316 4320.output

* GB784723 (A)

Description: GB784723 (A) ? 1957-10-16

Improvements in or relating to clamps for fixing dress guard stays on theaxles of perambulators or the like

Description of GB784723 (A)

PATENT SPECIFICATION Inventor: JAMES SPENCER 7 t /i g Date of filing Complete Specification: Jan16, 1956. Application Date: May 10, 1955 No 13447/55. Complete Specification Published: Oct 16, 1957. Index at acceptance:-Class 44, BE 4 84. International Classification:-FO 6 b. COMPLETE SPECIFICATION Improvements in or relating to Clamps for 'Fixing Dress' Guard Stays on the Axles of Perambulators or the like We, THE SPENCER MANUFACTURING COMPANY (TENBURY) LIMITED, a British Company of Bridge Buildings, Tenbury Wells, Worcestershire, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to clamps for the fixing of dress or wheel guard stays on the axles of perambulators or the like and it has for its object a clamp which can be readily fitted on an axle. According to the present invention, a clamp for fixing a dress or wheel guard stay on a wheel axle of a perambulator or the like comprises two clamping arms between which an axle is gripped, and is characterised in that each clamping arm is pivotally mounted on a metal strip forming the stay and in that an abutment on the metal strip or the clamping arm co-acts respectively with the clamping arm or the metal strip temporarily to retain the clamping arm relative to the other clamping arm and the metal strip so that the clamping arms are held in a spaced relation to enable the axle to be engaged between the clamping arms ready for tightening the clamping arms on the axle The clamping arm may be a strip of metal bent to open loop shape with

legs lying on each side of and pivoted to the metal, strip forming the stay The metal strip forming the stay may be corrugated or have projections thereon to form said abutments limiting the pivotal movement of the clamping arms In a modification also using clamping arms of open loop shape, each clamping arm is cranked inwardly over the metal strip forming the stay to form said abutment to limit the pivotal movement of the clamping arm. In order that the invention may be clearly understood and readily carried into effect, reference may be had to the accompanying drawings, on which: lPricd 3 s 6 d l Figure 1 is an elevation of a clamp constructed according to this invention. Figure 2 is an end elevation of Figure 1. Figure 3 is a section on line x-x of Figure 1. Figure 4 is an elevation of a modification and Figure 5 is an end elevation of Figure 4. According to a convenient embodiment of this invention as shown by Figures 1 to 3, a metal strip forms a stay 1 Two clamping arms 2 each formed from a strip of metal bent into open loop shape having two legs 3 riveted to the stay bar with the legs on each side, the rivet forming a pivot pin The rivets tightly grip the clamping arms to the stay to prevent looseness If the arms become displaced by being rocked on the rivets, time is wasted and the finished surface of the clamp mutilated in setting the arms to lie on each side of an axle 6 preparatory to being pulled against the axle by a clamping bolt 7, and this difficulty of setting the arms is accentuated after the parts have been plated or enamelled To overcome this, the stay 1 in the space between the arms is pressed to form two corrugations 4 and 5 A corrugation may also be pressed in the stay on the outer side of each clamping arm Thus each clamping arm is riveted by the pivot pin on the stay adjacent a corrugation which forms an abutment and prevents the arm being pivoted out of position The clamping arms are thus temporarily held in relation to one another and the stay bar 1 so that they are spaced to receive an axle 6 between them The arms are pulled together on the axle by the clamping bolt 7 passing through the loops in the arms Although the arms may be tightly riveted on the stay and may be further held by plating or enamelling, the bolt 7 will pivotally move the arms As the arms are held in position for engaging over the axle, time is not wasted in giving a preliminary setting to the arms The corrugation between the arms also gives a width of 54,723 bed for bearing on the axle, thereby ensuring a more efficient engagement of the clamp and additional precaution against looseness of play. According to the modification shown by Figures 4 and 5, the legs 3 a of the loop shaped clamping arms 2 a are cranked inwardly at 2 b at a

short distance above the metal strip forming the stay la, so that the cranked parts 2 b form abutments which co-act with the top of the stay la to limit the pivotal movement of the clamping arms on the pivot pins, so that they are normally retained approximately at right angles to the stay la, whilst being able to be pulled into the clamping position by the bolt 7.

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* GB784724 (A)

Description: GB784724 (A) ? 1957-10-16

Improvements in or relating to mechanical power transmission apparatus


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FR1148385 (A) US2863327 (A) FR1148385 (A) US2863327 (A) less Translate this text into Tooltip

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The EPO does not accept any responsibility for the accuracy of data and information originating from other authorities than the EPO; in particular, the EPO does not guarantee that they are complete, up-to-date or fit for specific purposes.

IATENT SPECIFICATION Inr entor: HOWARD FREDERICK HOBBS Date of filing Complete

Specification April 16, 1956. Application Date June 13, 1955. 784,724 No 16943/55. \ \ '; 7/ Complete Specification Published Oct 16, 1957. Index at acceptance: -Class 80 ( 2), D 3 (A: C). Internati Qnal Classification: -FO 6 h. COMPLETE SPECIFICATION Improvements in or relating to Mechanical lPower Transmission Apparatus We, Ho B Bs TRAN 53 MISSION LIMITED, a British Company, of Sydenham House, 7 d, Itussell Terrace, Leamington Spa, Warwickshire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be parti culariy described in and by the following statement:- This invention relates to mechanical power transmission apparatus of the kind in which changes in ratio are made by the engagement and disengagement of one or more friction clutches or brakes which are actuated by hydraulic pressure, and which incorporates a pressure relief valve which controls the pressure in the hydraulic system and which is associated with the throttle control of the engine to which the transmission apparatus is attached so that the pressure in the system, or pressures in various parts of the system, is variel in accordance with the position of the throttle, thereby varying the pressure in accordance with the torque output of the engine It is desirable in a transmission apparatus of this kind to provide comparatively low operating hydraulic pressure vwhen the throttle is shut so as to ensure that the changes in ratio are made smoothly, for example when coining to rest, but it is also necessary to have sufficient pressure when the throttle is opened to transmit thle power without slip The engihe may develop considerable torque at low speed even with the throttle opened a small amount. The object of the present invention is to provide a relief valve connected to the throttle control of an engine which is adapted to provide ( 1) some given low pressure when the throttle is fully released (e.g in a motor-car the accelerator pedal is released so that the throttle is at its minimum opening), ( 2) increased presll Price 3 s 6 d l sure when the throttle opening is slightly increased, and ( 3) substantially the maximum pressure when the throttle is moved some predetermined part of its travel. One of the difficulties with the throttle connected type of relief valve is the additional load imparted to the throttle pedal of a vehicle so fitted, particularly when it is required to increase the pressure rapidly over a comparatively small part of the travel of the pedal. According to the invention, a relief valve comprises a piston in a

bore, which can be urged against the pressure in the system by means of three springs, viz ( 1) a first spring which acts on the piston and provides a given minimum pressure, ( 2) a second spring of higher rate than the first spring which can be compressed by a pin operatively connected to the throttle control member (e g the accelerator pedal) and which spring is mounted within the relief valve piston and retained therein under compression and arranged to be ineffective when the throttle is completely released, but owing to its initial compression increasingly effective when the throttle opening is slightly increased, and ( 3) a thilrd spring or springs of lower rate than the second spring carried by the pin so that when a given compression of the high rate spring is obtained by movement of the pin, the spring ( 3) will yield thereby providing a lower rate of increase with increased movement of the control member. According to a further feature of the invention, the pin is associated with a second piston working in a bore connected to the hydraulic pressure system of the transmission whereby the pressure acting on the piston will partially overcome the loads on the pin produced by the coimpression of the springs thereby reducing the load to be applied by a throttle pedal. 9 Q aa r -t I ' ' Ales i -) V 784,724 The invention will now be described by way of example with reference to the accompanying diagrammatic drawing which is a sectional view of a valve made in accordance with the invention. A valve block 10 contains a channel 11 which is connected to an oil pump output and through a control valve (not shown) to the brakes and/or clutches to be controlled The channel 11 is in direct communmication with both ends 12, 13 of a bore which consists of three parts 14, 15, 16 of different diameters, the part 1-5 of smallest diameter being between the part 14 of intermediate diameter and the part 1 6 of largest diameter. The part 14 contains a valve piston 17 which piston has a part of larger diamieter slidably engaging the bore part 14 and a part of smaller diameter slidably engaging the bore part 15. The smaller end of the piston 17 seats on a ring 20 that slides in the bore part 1, the ring 20 being under pressure irom a first spring 21 that engages between the ring 20 and a plunger 22 that also is Alidably engaged in the bore part 16 and is carried by a rod 23 that passes out or dhe valve block 10 through a hole in a boss, 24. This rod 23 has a part 25 of reduced diameter engaged in a hole in a lever 26 that is carried by a l Aivot 27 which is actuated by the throttle control member of the engine with which the apparatus is associated, e g an accelerator pedal 29 connected by link 33 and arm 37 to the lever 26 The lever 26 can return by sliding over the reduced

diameter part 2 3 even if the valve rod 23 should jam The rod 23 carries a stop ring 28 for the purpose of limiting the travel of the rod 23. A spring 41 urges the parts 33, 37,29, in the throttle closing direction. The piston 17 is hollow and contains the second spring 30 which is held in position under an initial load by a spring ring 31. A washer 3 t 2 is interposed between the spring 30 and the ring 31. A pin 34 has a part of reduced diameter which forms a a shoulder 36 The pin carries three abutments The first abutment 38 is in the form of a sleeve slidablle on the pin and normnally spaced from the washer 32 to provide a small amount of lost motion. The second abutment 39 is a fixed part of the pin 34 and the third abutminent 40 slidable on the reduced diameter part of the pin and seating against the shoulder 36 The third spring 42 is engaged under an initial loading between the abutments 39 40. The valve block 10 has an exhaust duct 44 communicating with the bore part 14. The reduced diameter part of the piston 17 forms a shoulder 47 having an area less than the area of the head surface 48. Fluid pressure from channel 11 is lead by a duct 49 to a valve cylinder 50 containing a valve member 51 having a groove 32 70 therein which provides colmmunication between the duct 4 J 9 and a duct 5; 3 which is in coummunication with the Lore part 14 at the reduced diameter p art of the piston 17 so as to provide a pres-sure on the area 75 47 counter to the pressure on the area 48. The rmembter 51 is movable to cut oft this counter pressure in at least one transmission ratio, e g top) gear (direct drive) whereby higher fluid piess-ures exiit in 80 the channel 11 in higher transmission ratios so that in these ratios in which higher torque is transmitted the engaging pressures of the clutches and brakes wilt be increased as 85 compared with direct drive. The spring 30 is a higher rate spring than the spring 42 but has a lower initial loading For example in a particular example the rate of tue sp Liing':3 is 4 L:) 90 per inch of compression and the rate of the spring 142 is 10 lb pier nch of conmpression; the initial loading on the spring is 4 lb and the initial loadin is 14 lbs; the rate of the spring 21 is 51 b per 95 inch of compression. In the normal positioins of the parts, i.e when the throttle control is released, the pressure of the spring 21 and the fluid pressure on the area 47, tends to 100 move the valve piston 17 to close the exhaust duct 44 against the pressure in the channel 11 acting on the valve piston area 48 The pressure in the channel 11 is determined accordingly A small open 105 ing of the throttle brings the abutment

38 up to the ring 32 -Further opening of the throttle results in compression of the spring 30 since its initial loading is less than that of the spring 4-2 Consequently 110 the pressure of fluid in the channel 11 will increase accordingly As the throttle is opened still further the spring - O becomes loaded up to the initial loading of the spring 42 whereafter further 115 throttle opening results in further coinpression of the spring 42 as well as the compression of springs 21 and 30 with consequent inerease of pressure in the channel 11 available for engaging the 120 clutehes and brakes. It would be possible o reduce the load and the force exerted lb die springs by reducing the effective area oa the relief valv-e A valve of this kind should however 125 be of such dimensions as to ierimit reiativelv unrestricted flaw of thle oil or otler fluid; also if it is desianed with nmall effective areas and liht springs the tendency to stick is increased A valve 130 784,724 constructed according to the present invention however may advantageously employ substantial spring loads so as to avoid tendency to stick in operation.


* GB784725 (A)

Description: GB784725 (A) ? 1957-10-16

Improvements in or relating to sealing ring collapsing means and method



US2801891 (A) US2801891 (A) less Translate this text into Tooltip



PATENT SPECIFICATION Date of Application and filing Complete Specification: June 24, 1955. 784,725 No 18305/55. Application made in United States of America on June 29, 1954. Complete Specification Published: Oct 16, 1957. Index at acceptance:-Class 122 ( 1)5 B 7 X. International Classification:-F 06 j. COMPLETE SPECIFICATION Improvements in or relating to Sealing Ring Collapsing Means and Method I, JOHN Z DELOREAN, a Citizen of the United States of America, of 1,669 Bournemouth Road, Grosse Pointe Woods, Michigan, United States of America, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:This invention relates to sealing rings and methods of collapsing them and particularly to a combination of collapsing and sealing rings and method of assembly. The present invention provides a piston and ring assembly, including a piston having an annular groove therein, a sealing ring in said groove having a collapsing ring thereabout for retaining the sealing ring in collapsed position, and a second groove for receiving said collapsing ring after said piston is disposed within a cylinder and said sealing ring is in engagement with the inner wall thereof. The present invention further provides a method of assembling a piston ring within the bore of a cylinder which includes the steps of: maintaining the sealing ring in collapsed position within a first groove by a band disposed thereabout, and moving said band into a second groove as the piston is inserted within the cylinder and the sealing ring engages the wall thereof. Difficulty has always been experienced when collapsing split sealing rings into the grooves of pistons at the time the piston is moved within a cylinder This is particularly true in blind hole applications, and the present invention pertains to a sealing ring having a collapsing ring associated therewith which retains the sealing ring collapsed during the assembly of the piston within the

blind ended cylinder The sealing ring may be grooved to receive and retain the collapsing ring thereon, or the collapsing ring may be sinuously formed to extend over a portion of the piston while retaining the ring collapsed. Preferably an additional slot is provided adlPrice 3/61 jacent to the sealing ring slot so that after the sealing ring is retained collapsed and the collapsing ring has moved therefrom, it will collapse into the adjacent groove and in no 50 manner interfere with the operation of the piston or other element which is sealed thereby. Accordingly, the main objects of the invention are: to provide a sealing ring with a 55 collapsing ring which retains it in collapsed position; to provide a cylindrical element to be sealed with a slot for receiving the sealing ring and an adjacent slot for receiving the collapsing ring after the element has been 60 moved into a cylinder; to provide a sealing ring with a groove in the outer wall in which the collapsing ring is retained until the cylinder moves the collapsing ring from engagement with the sealing ring permitting the 65 sealing ring to engage the wall of the cylinder, and in general to provide a sealing and collapsing ring and a method of maintaining the sealing ring collapsed until engaged with the cylinder wall, all of which is simple in con 70 struction, positive in operation, and economical of manufacture. Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for a 75 better understanding of the invention, to the following description taken in conjunction with the accompanying drawings, wherein:Fig 1 is a sectional view of a piston and cylinder assembly having sealing means there 8 & for embodying features of the present invention, with the cylinder and piston shown in a separated position; Fig 2 is a view of the structure illustrated in Fig 1 with the piston and cylinder in 5 partially assembled position; Fig 3 is a view of the structure illustrated in Figs 1 and 2 with the cylinder and piston in complete assembled position; Fig 4 is a sectional view of the structure 9 g illustrated in Fig 1, taken on the line 4-4 thereof; 784,725 Fig 5 is an enlarged sectional view of the structure illustrated in Fig 1, as viewed within the circle 5; Fig 6 is an enlarged sectional view of the structure illustrated in Fig 2, as viewed within the circle 6; Fig 7 is an enlarged sectional view of the structure illustrated in Fig 3, as viewed within the circle 7; Fig 8 is a view of structure, similar to that illustrated in Fig 5, showing a further form which the invention may assume; Fig 9 is a view of structure, similar to that illustrated in Fig 5, showing still another form of the invention; Fig 10 is a view of structure, similar to that illustrated in Fig 5, showing still a further form which the invention may assume; Fig 11 is

a plan view of a sealing and collapsing ring assembly embodying features of the present invention; Fig 12 is an enlarged sectional view of the structure illustrated in Fig 11, taken on the line 12-12 thereof; Fig 13 is a view of structure similar to that illustrated in Fig 11, showing a different form thereof; and Fig 14 is a view of structure similar to that illustrated in Fig 11, showing a still further form which the invention may assume. Referring to Figs 1 to 7, inclusive, a cylinder 15 is illustrated in which a piston 16 is to be inserted A piston ring 17 is disposed in an annular slot 18 in the piston peripheral wall and is collapsed by suitable tools (not shown) when the piston is moved within the cylinder The cylinder 15 has a concentric piston 19 which mates with a cylinder 21 of the piston 16 A ring 22, which is to seal with the wall of the cylinder 21, is inaccessible and cannot be reached by a collapsing tool. Applicant has provided a sealing ring 22 having a collapsing ring 23 associated therewith to retain the sealing ring collapsed while the piston 19 is being inserted into the cylinder 21 In order to dispose of the ring 23 as it is moved from engagement with the sealing ring 22, an annular slot 24 is provided in the piston wall adjacent to the slot 25 in which o the sealing ring 22 is disposed. As the piston 19 advances into the cylinder 21, the collapsing ring 23 is moved from engagement with the sealing ring 22 while the sealing ring is retained from expanding by the wall The continued movement of the piston 19 into the cylinder 21 advances the collapsing ring 23 until it collapses into the annular slot 24 out of contact with the cylinder wall 21. It will be seen in Fig 2 that the sealing ring 22 is confined by the wall of the cylinder 21 and that the collapsing ring 23 is advanced along the wall of the piston 19 out of engagement with the sealing ring 22 In Fig 3 the collapsing ring is shown disposed within the slot 24 and out of engagement with the wall of the cylinder which is sealed by the sealing ring 22 This same relationship is illustrated in Figs 5, 6 and 7, Fig 5 showing the ring 22 collapsed within the slot 25 by the collapsing ring 23, Fig 6 showing the cylinder 70 21 engaged by the sealing ring 22 and the collapsing ring 23 advanced toward theslot 24, while Fig 7 shows the collapsing ring 23 disposed within the slot 24 Fig 4 shows the sealing ring 22 disposed within the slot 25 75 and retained collapsed by the collapsing ring 23. Various means may be provided for retaining the collapsing ring in position to retain the sealing ring collapsed In Fig 8 a 80 wire collapsing ring 27 is illustrated as being of corrugated form, having parts thereof engaging the sealing ring 22 and other parts thereof engaging the annular wall of the piston 19 In this relationship an

adjacent 83 slot 28 is widened so that the wide corrugated ring can collapse therein when pushed from a position of engagement with the sealing ring 22 In this arrangement, the corrugated ring 27 need not be accurately positioned to 90 effectively collapse the ring 22. In Fig 9 a flat collapsing ring 31 is illustrated which functions in the same manner as the corrugated ring 27 having a portion thereof engaging the sealing ring 22 and re 95 taining it in collapsed position while another portion thereof rests upon the face of the piston 19. In Fig 10 a sealing ring 33 is illustrated of greater width disposed in a wider slot 34 in 100 the piston wall A collapsing ring 35 similar to the collapsing ring 23 retains the sealing ring 33 collapsed until engaged by the wall of the cylinder The sealing ring has a central slot 36 of sufficient width to receive the 105 collapsing ring 35 into which the latter is moved as the piston is advanced into the cylinder. In Figs 11 and 12 a sealing ring 37 is illustrated having a collapsing ring 38 secured 110 thereto In this relationship the sealing ring has an arcuate groove 39 therein to accurately centre the collapsing ring 38 and retain it in unit relation to the sealing ring until forcibly pushed therefrom by the cylinder as the 115 piston is advanced thereto. In Fig 13 a sealing ring 39 is illustrated having a collapsing ring 38 secured thereto and retained in operative relationship therewith by an arcuate groove 41 which extends 120 over an arcuate area of approximately 90 degrees opposite to the abutted ends of the ring 39. In Fig 14 sealing ring 42 is illustrated having a collapsing ring 38 secured thereon 125 engaged in an arcuate recess 41 opposite to the abutted ends of the ring 42 and in two arcuate recesses 43 which are adjacent to said abutted ends In any of the constructions, the sealing and collapsing rings are retained 130 784,725 in unit engagement and the piston or the sealing ring is provided with an annular slot into which the collapsing ring is moved after the sealing ring has engaged the cylinder wall and is retained collapsed thereby in sealing relation therewith.


* GB784726 (A)

Description: GB784726 (A) ? 1957-10-16

Improvements in or relating to the vaporisation of liquefied gases



FR1151245 (A) FR1151245 (A) less Translate this text into Tooltip



PATENT S Pi ECIFICATION Inventor: JOHN BAXTER GARDNER Date of filing Complete Specification May 22, 1956. Application Date July 15, 1955. 84 o 726 No 20570/55. ., '; Complete Specification Published Oct 16, 1957. Index at Acceptance: -Class 8 ( 2), P 2. International Classification: -F 25 j. COMPLETE SPECIFICATION Improvements in or relating to the Vaporisation of Liquefied Gases We, THE BRITISH OXYGEN COMPANY LIMITED, a British Company, of Bridgewater House, Cleveland Row, St James's, London, S.W 1, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the vaporisation of liquefied gases such as for example liquid oxygen or liquid nitrogen. It has previously been proposed to vaporise such liquefied gases by

heat exchange in a suitable vaporiser with air either at atmospheric temperature or previously heated Heretofore, such processes have suffered from the disadvantage that moisture contained in the air used as vaporising medium tends to be deposited as ice in the vaporiser and thus to impair its efficiency. It is an object of the present invention to provide a method of and apparatus for the vaporisation of liquefied gases using heated air or other gas as the vaporising medium in which there is no risk of the deposition of substantial amounts of frost. It is a further object of the invention to provide apparatus for the vaporisation of liquefied gases which is compact, light and economic. According to one aspect of the present invention, a process for vaporising a liquefied gas comprises passing a stream of the liquefied gas through a vaporiser in heat exchange with a stream of heated air or other gas, whereby the liquefied gas is vaporised and the heated air or other gas is cooled, and recycling the cooled air or other gas to the vaporiser through heating means wherein the air or other gas is re-heated, prior to entering the vaporiser, sufficiently to prevent substantial deposition of ice. According to another aspect of the invention, apparatus for vaporising a liquefied gas comprises a vaporiser, means for passing a stream of the liquefied gas through the lPrice 3 s 6 d l vaporiser means for passing a stream of heated air or other gas through the vaporiser in heat exchange with the liquefied gas stream, means for recycling such cooled air 50 or other gas to the vaporiser, and means for re-heating such recycled air or other gas prior to its entry into the vaporiser. Since in the process of the present invention a closed air or other gas cycle is used, the 55 amount of water vapour present is only that initially contained in the air or other gas together with that contained in any small quantity of make-up air or other gas which it may be necessary to draw into the system to replace 60 unavoidable losses, and there is accordingly no possibility of the occurrence of substantial deposition of frost in the vaporiser This enables relatively compact vaporisers to be used, since it is not necessary for the wall ternm 65 perature on the heated side to be above the freezing point of water. Any suitable arrangement for heating the air or other gas stream may be used but preferably it is heated by heat exchange with hot 70 combustion products produced by the combustion of oil or like cheap fuel In order to prevent overheating of the air or other gas, the heater may be provided with an automatic temperature control 75 The means for passing the stream of liquefied gas through the vaporiser will normally consist of a liquid pump, which may be of any convenient type Similarly, the means for circulating the air or other gas stream

may con 80 sist of a fan. In order to obtain the most efficient conditions for vaporisation, the heated air or other gas stream may be passed through the vaporiser counter-current to the liquefied gas 85 The vaporiser itself can conveniently be in the form of a coil through which the liquefied gas is passed, the heating air or other gas being passed over the outside of this coil. The apparatus of the present invention is 90 economical to operate since the heater may be operated with cheap fuel oil, Moreover, it may rki 25 p 784,726 be made sufficiently compact and light as to be suitable for use on a vehicle. A further advantage of the present invention is that it is completely self-contained as regards the supply of heat, that is to say there is no requirement for electrical, steam or other power supply, other than for the small amount of power required to drive the pump and fan. The invention will now be more particularly described with reference to the accompanying drawing which shows diagrammatically one form of apparatus according to the invention. The apparatus comprises a vaporiser 1 consisting of a coil 2 connected at one end by a pipe 3 to a liquid pump, 4 itself connected to a source of the liquefied gas The other end of the coil 2 is connected by a pipe 5 to a receiver for the vaporised gas. The coil 2 is housed within a tubular outer container 6 connected at its end adjacent the pump 4 by pipe 7 to the intake of a fan 8, the output of which is connected by a pipe 9 to one end of the outer shell of a heat exchanger 10 The other end of the heat exchanger 10 is connected by a pipe 11 to the end of the container 6 adjacent the pipe 5. An inlet 12 for make-up air or other gas to cover leakage is located in the pipe 7 upstream of the fan 8. The heat exchanger 10 comprises an outer shell 13 surrounding and spaced from an inner tube 14 which is connected at one end to the output of a fan 15, the inlet of which is open to the atmosphere, and at the other to an exhaust pipe 16 A burner nozzle 17 located within the tube 14 at its end adjacent to the fan 15 is connected by a pipe 18 through a pump, 19 to a source of oil (not shown). In operation, oil supplied to the burner nozzle 17 by the pump 19 is burnt in the air stream supplied by the fan 15, the hot combustion products passing through the inner tube 14 of the heat exchanger 10 and out through the exhaust pipe 16 Air or other gas circulated by the fan 8 passes through the outer shell 13 of the exchanger 10 where it is warmed by heat exchange with the hot comnbustion products. The warmed air or other gas then passes through pipe 11 into the outer container 6 of the vaporiser 1 through which it passes in indirect

heat exchange counter-current to liquefied gas forced through the ceil 2 by the liquid pump 4 The liquefied gas is thereby vaporised and the compressed vaporised gas passes through pipe 5 to the receiver Simultaneously, the air or other gas is cooled The cooled air or other gas passes through pipe 7 to the fan 8 and thence again to the exchanger where it is re-heated prior to returning the vaporiser 1 Any loss of air or other gas during its passage through the cycle is made up by bleeding in additional air or other gas through the inlet 12 The above illustration is of one paticular form of the invention It will be understood that different types of heat exchange equipment and detailed alteration to the arrangement could be made which would 70 still be within the scope of the invention For example any other form of heating the air or other gas circulating between the liquefied gas vaporiser 1 and the heat exchanger 10 could be used 75


* GB784727 (A)

Description: GB784727 (A) ? 1957-10-16

Improvements in or relating to carboxylic acids

Description of GB784727 (A) Translate this text into Tooltip



COMPLETE SPECIFICATION Improvements in or relating to Carboxylic Acids We, THE M. W. KELLOGG COMPANY, a Corporation organised under the laws of the State - of Delaware, United States of America, of Foot of Danforth Avenue, Jersey City, 3, New Jersey, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment:- This invention relates to a new and useful class of fluoroperhalogenated organic compounds and to new methods of preparation for both this new class of compounds and for useful compounds already lonown. More particularly, it relates to new fluoroperhalogenated carboxylic acids and their salts and to new methods of preparation of perfluorocarboxylic acids and fluoroperhalogenated carboxylic acids and their salts. It is imown that polyfluoro alkanoic acids and polyfluoropolychloro alkanoic acids may be prepared by heating a completely halogenated ethylene with methanol in the presence of a free radical producing catalyst to produce polyfluoro alkanols of the formula ll(CF,CF2)n CHCEI, or the corresponding polyfluoropolychloro alkanols, and thereafter oxidizing the alkanols to alkanoic acids. The polyiluoro alkanoic acids and polyfluoropolychloro alkanoic acids, thus produced, are useful compounds in that they have good thermal stability and inertness along the aliphatic chain, and in @@at they are compatible with fluorocarbon polymers and fluorochlorocarbon polymers, so that they may remain as harmless residues in polymers produced when they are used as emulsifiers in polymerization processes. However, such polyhalc alkanoic acids are not as stable as they would be without the hydrogen at@m on the terminal carbon furthest removed from the carboxylic group since its presence may lead to the elimination of hydrogen halide and thereby result in the corrosion of metal parts. This may lead to further breakdown of the halo acid due to the reactivity of the carbon-carbon double bond produced. It is also to be noted that the polyhalo alkanoic acids prepared in this manner can only be hose having an odd number of carbon atoms. It is also mown that perfluoro alkanoic acids having the general formula F(CF2)nCOOH may be prepared by the electro-chemical fluorination of alkanoic acids in anhydrous hydrogen fluoride with subsequent hydrolysis of the resulting fluorinated acid fluorides. Such acids, being completely halogenated, are quite stable and may be prepared in chain lengths of either an odd or an even nurnber of carbon atoms. However, this method has not been shown to be applicable to the preparation of long chain fluoroperhalo alkanoic acids,

containing halogen atoms other than fluorine, and the presence of other halogen atoms is often desirable to impart desired solubility characteristics and increased compatibility with polymers containing halogen atoms other than fluorine. Furthermore, the yield of long chain acid is likely to be lowered, due to the increased statistical probability of scission in the fluorination of long chain alkanoic acids. The expense and low yields are major drawbacks of the electrochemical process. It is an object of this invention to provide new fluoroperhalogenated aliphatic carboxylic acids, and their salts, esters, and anhydrides. It is a further object of this invention to provide a method of preparing fluoroperhalo aliphatic carboxylic acids and their salts in any desired carbon chain length. It is a further object of this invention to provide a method of preparing fluoroperhalo aliphatic carboxylic acids and their salts having an even number of carbon atoms in the aliphatic chain. It is a further object of this invention to provide a method of preparing fluoroperhalo aliphatic carboxylic acids and their salts having an odd number of carbon atoms in the aliphatic chain. It is a further object of this invention to provide a new method of preparing pe' fluoro aliphatic carboxylic acids and their salts. It is a further object of this invention to produce new fluoroperhalo aliphatic carboxylic acids of specific structure in high yields. Still another object of this invention is to produce new perfluoro and fluoroperhalo aliphatic dicarboxylic acids which are useful in condensations with polyalcoliols to produce long chain highly halogenated polyester polymers. Still another object of this invention is to produce new fluoroperhalo aliphatic carboxylic acids and salts which are useful as dispersing agents for the emulsion polymerization of halogenated olefins. Still another object of this invention is to produce new flueroperhalo aliphatic carboxylic esters which are useful as softening agents and plasticizers for the halogenated polymers. Still another object of this invention is to produce new fluoroperhalo aliphatic carboxylic acid salts which may be used as gelling agents in grease compositions containing chlorotrifluoroethylene polymers. Still another object of this invention is to produce new fluoroperhalo aliphatic carboxylic acids which are thermally stable and may be heated indefinitely to temperatures of 200 C. and above. Still another object of this invention is to produce new fluoroperhalo aliphatic carboxylic acids and salts which may be used as surface active agents which can be used in highly acid and/or highly oxidative environments, as, for example, in electroplating baths, where ordinary

surface active agents would be decomposed. Other objects will appear hereinafter. These and other objects and advantaes are obtained by treating with fuming sulfuric acid a fluorine-containing telomer prepared by telomerizing an olefin which is preferably at least half fluorinated in the presence of a sulfuryl halide or a perhalogenated methane containing a bromine atom. Among the preferred telomers which are treated according to. this invention are those with the general structure CCl,-(CF2-CFCl)-Br wherein n is an integer from 1 to 16. These telomers are prepared by the telomerization of chlorotrifluoroethylene in the presence of the telogen, bromotrichloromethane. The telomerization preferably takes place in the presence of benzoyl peroxide which is dissolved in the bromotrichloromethane while the chlorotrifluoroethylene monomer is added under pressure in a dosed system. In a specific example, 3.5 parts of benzovl peroxide may be dissolved in 405 parts of bromotrichloromethane and charged to a pressure vessel along with 300 parts of chlorotrifluoroethylene. The system is heated for about 4 hours at about 100 C., with agitation to produce high yields of relatively low molecular weight polymers having the above formula. The telomeric product is relatively easy to separate into its individual compounds by distillation since it contains only compounds having an odd number of carbon atoms, so that each compound has a boiling point relatively far removed from that of the next lower or next higher compound. Thelomers produced by perhalomethanes other than bromotrichloromethane as telogens may also be used, provided they contain a bromine atom and provided they do not produce, at the end of the telomer molecule opposite the bromine atom, an end group which is more easily hydrolyzed than the CFCIBr end group which is converted to a carboxylic acid end group in accordance with this invention. The preferred telogens other than bromotrichlorcmethane are the perhalogenated methanes: bromotrifluoromethane, bromochlorodifluoromethane, bremodichlorofluoromethane, dibromodifluoremethane, and dibromochlorofluoromethane. All of these telogens produce telomers containing a CFC!Br group at one end of the molecule and containing at the opposite end a perhalomethyl group which is not more susceptibl- to hydrolysis than the aforesaid CFCIBr group. For convenience, these perhalomethyl groups may be designated as those having a total atomic weight not higher than 146.5, the atomic weight of the bromochlorofluoromethyl group. In general, these telomers may be represented by the structural formula Y(CF2CFCl@Br or as Y.CF2(CFClCF2)n-1-CFClBr, wherein n is defined as above and Y is a

perhalomethyl group having a total atomic weight not higher than 146.5 these telomers produce monocarboxylic acids of the formula Y CF2(CFCl CF2)n-1COOH and diacids of the formula HOOCCF2(CFClCF2)n-1COOH, wherein Ya and n are defined as above. For convenience in providing a generic expression with other acids discussed below, the mono acids and diacids may be written as YaCF2CFCl(CF2 CFCl)n-2CFCOOH and HOOCCF2CFCl (CF2CF1)n-1CF2COOH @@spectively. Abother of the preferred telomers which are treated according to this invention are those with the general structure, C1(CF2-CFCl)n Cl, wherein n is an integer from 2 to about 16, These telomers are prepared by the telomerizing of chlorotriflueroethylene in the presence of the telogen, sulfuryl chloride. The telomerization preferably takes place in the presence of benzoyl pero@ide which is dissolved in a solvent, such as carbon tetrachloride, while the chlorotriflurocethylene monomer is added under pressure in a closed system. In a specific example, 3.5 parts of benzoyl peroxide are dissolved in 308 parts of carbon tetrachloride and 135 parts of sulfuryl chloride, 116 parts of chlorctrifluoro@thylene monomer is added and the system is heated to about 95 C. for a period of 4 bours with agitation to produce a high yield of relatively low molecular weight polymers having the above formula. The telomeric product is relatively easy to separate into its individual compounds by distillation since it contains only compounds having an even number of carbon atoms, so that each compound has a boiling point relatively far removed from that of the next lower or next higher compound. The telomerization reaction is aided by the presence of sulfur dioxide as a modifying agent in a mole ratio between about 1 to 10 and 10 to 1 witli the catalyst. Telomers produced by sulfuryl halides other than sulfuryl chloride, as telogens, may also be used, provided that they do not produce at the CFC1 end of the terminal monomeric finit an end group containing additional fluorine. The preferred halogens other than sulfuryl chloride are sulfuryl bromide, fluorosulfuryl chloride and bromosulfuryl chloride. All of these telogens produce telomers containing a -CFCl2 or -CFClBr end group at one end of the molecule, which may be hydrolyzed in accordance with this invention to produce a carboxylic acid. In general, the telomers of chlorotrifluoroethylene which may be used may be designated a having the formula Yb(CF2-CFCl)nYc wherein Yb is a halogen selected from fluorine, chlorine and bromine; We is a halogen selected from chlorine and bromine and having an atomic weight not lower than that of Yb, and n is an integer from 2 to about 16. These telomers produce

monocarboxylic acids of the formula Yb(CF2-CF Cl)n-1-CF2-COOH and diacids of the formulae HOOC-CFCl-(CF2-CFCl)n-2 CF2-COOH and HOOCCF2(CF2CFCl)n-2 CF2COOH wherein Yb and n are defined as above. The diacid of the latter formula usually predominates and is apparently formed by halogen transfer between the terminal carbon atoms and its adjacent carbon atom just before hydrolysis. To be consistent with the designation used for the bromoperhalomethane telomers and telomer products. the sulfuryl halide telomers may be represented by the formula YbCF2 (CFClCF2)n-1CFClYc, the mono-acids by the formula YbCF2(CFClCF2)n-ICOOH, and the diacids by the formula HOOC(CFClCF2)n-1 COOH, wherein Yb, Yc and n are defined as above. All of the acids produced from chiorotri- fluoroethylene telomers by this invention may be represented by the generic formula Z(CF2CFCl)n-2CF2COOH, wherein Z is a monofunctional radical consisting of the YaCF2CFCl-YbCF2CFCl-, HOOC,CF2CF Cl-HOOC.CFCl-, or HOOC.CF2- radical, Ya in the first mentioned radical of said group being a perhalomethyl radical having a total molecular weight of not higher than 146.5 and Yb in the second mentioned radical of said group being a halogen atom consisting of fluorine, chlorine or bromine, and wherein n is an integer from 1 to 16. Telomers produced from perhalogenated monomers other than trifluorochloroethylene may also be used as starting materials in this invention. Among the perhalogenated monomers which may be used, in addition to chlorotrifiuoroethylene, are tetrafluoroethylene and unsymmetrical dichlorodifluoroethylene. In general, the perhalogenated monomers may be designated as those having the structure CF2=CXaXb wherein Xa and Xb may each consist of a fluorine or chlorine atom. These monomers may be either homotelomerized or cotelomerized with each other or with other halogenated olefins, including hydrogen-containing olefines. In order to maintain the chemical stability of the final products, it is preferred that the hydrogen content be kept at a minimum so that the hydrogen-containing olefines should contain at least two fluorine atoms. For optimum stability, it is preferred that no hydrogen be present Among the halogenated olefins which may be cotelomerized with the aforesaid perhalogenated monomers are, symmetrical dichlorodifluoroethylene, trifluoroethylene and vinylidene fluoride. To produce high yields of fluoroperchloro aliphatic acids of specific structure, homotelomers must be used, since it is impossible to predict the order of alignment of the

individual comonomer units in a cotelomer. The telomers produced from the aforesaid monomers by telomerization with bromoperhalomethane telogens may be designated as Ya(CF2-CXaXb)n-Br wherein Xa and Xb are each a halogen atom consisting of either a fluorine or a chlorine atom. Ya is a perhalomethyl radical having a total atomic weight not higher than 146.5, and n is an integer from 2 to 16. These telomers, when reacted with fuming sulfuric acid, produce monoacids of the formula M-(CF2-CXaXb)n-1-CF2 COOH, and diacids of the formula HOOC (CF2-CXaXB)n-1-CF2-COOH, wherein Xa,Xb, M and n are defined as above, depending upon the conditions of treatment. Alternatively, using a designation consistent with the designation used for the generic expression for chlorotrifluoroethylene telomers, the monoacids may be designated as YaCF2CXaXb (CF2CXaXb)n-2CFCOOH, and the diacids as HOOC. CF2CXaXb - (CF3CXaXb)n-2CF2 COOH, wherein Xa and Xb and n are defined as above, and wherein Za represents a perhalo ethyl radical wherein the two halogen atoms of the carbon adjoining the first monomeric unit are fluorine atoms. The telomers produced from the aforesaid monomers by telomerization with the particular telogen, bromotrichloromethane, may be designated as CCl3-(CF2-CXaXb)n-Br wherein Xa and Xb and n are defined as above. Such telomers produce monoacids of the for mula CCl3-(CF2-CXaXb)n-1-CF2-COOH, and diacids of the formula HOOC-(CF2 CXaXb)n-1CF2-COOH, wherein Xa, Xb and n are defined as above, again depending upon the conditions of treatment In a designation consistent with that used above, the monoacids may be represented by the formula CCl3CF2(CXaXbCF2)n-1-COOH, and the diacids by the formula HOOCCF2 (CXaXbCF2)n-1COOH, wherein Xa, Xb and n are defined as above. The telomers produced from chlorotrifluoroethylene with any of the aforementioned teloW gens may be defined as having the formula Ya-(CF2CFCl)N-Br wherein Ya and n are defined as above. Such telomers, when reacted with fuming sulfuric acid, produce acids of the formula Zb(CFClCF2)n-1COOH, wherein Zb is a monofunctional radical consisting of perhalomethylene carboxylic acid radicals or perhaloethyl radicals, wherein all of the halogen atoms of the radical are selected from fluorine, chlorine and bromine atoms, and wherein the two halogen atoms of the carbon atom adjoining the first monomeric unit are fluorine atoms, and wherein the total atomic weight of the terminal perhalo group is not higher than 146.5. More specifically, depending upon the conditions d treatment, such re2ctions will rro duce monoacids of the formula Ya-CF2(CFCl CF2)n-1COOH, and diacids of the formula HOOC-CF2(CFClCF2)n-1-COOH.

The telomers produced by the telomerization of chlorotrifluoroethylene with bromotrichloromethane may be designated as CCl3 (CF2-CFCl)n-Br, wherein n is defined as above. Such telomers, when reacted with fuming sulfuric acid, produce monoacids of the formula CCl3CF2(CFClCF2)n-1-COOH and diacids having the formula defined in the last paragraph. The telomers produced from any cf the aforesaid monomers by telomerization with a sulfuryl halide may be designated as, Yb (CF2-CXaXB)nYc wherein Yb is a halogen selected from fluorine, chlorine and bromine; Ye is a halogen selected from chlorine and bromine, and having an atomic weight not lower than that of Yb; Xa and Xb are halogens selected from fluorine and chlorine, and n is an integer from 2 to 16. These telomers produce carboxylic acids having the general formula Z@(CXaXbCF2)n-1COOH, wherein Z is a monofunctional radical elected from the group consisting of carboxylic acid radicals and perhalomethyl radicals containing halogen atoms selected from fluorine, chlorine and bromine atoms of which at least two are fluorine atoms, and Xa, Xb and n are defined as above. More specifically, the aforementioned telomers may be said to produce dicarboxylic acids of the formulae HOOCCXaXb(CF2CXnXb)n-2CF2 COOH and HOOCCXaXb(CF2CXaXb)n-2CF2 COOH, wherein Xa, Xb and n are defined as above, and monoacids of the formula YbCF2 (CXaXbCF2)n-lCOOH wherein Y@, Xa, X@ and n are defined as above, The telomers produced from the aforesaid monomers with the specific telogen, sulfuryl chloride, may be designated as, Cl-(CF2 CXaXb)n-Cl wherein Xa, Xb and n are defined as above. These telcmers produce dicarboxylic acids of the formula specified in the immediately preceding paragraph, and monocarboxylic acids of the formula CF2Cl(CXaXb CF2)n-1-COOH, wherein Xa, X@ and n are defined as above. The telomers produced by the telomerization of chlorotrifluoroethylene with sulfuryl chloride have been designated above as Cl (CF2-CFCl)n-Cl, wherein n is an integer from 2 to 16. Such telomers produce monocarboxylic acids of the formula OF2Cl(CFC1 CF2)n-1-COOH, and dicarboxylic acids of the formulae HOOCCF2(CF2CFCl)n-2COOH and HOOCCFCl)-CF2CFCl)n-2COOH. The process of this invention is applicable to telomers containing from 2 to about 16 monomer units. Telomerization with any of the aforesaid perhalo methanes as telogens produces good yields of telomers having up to about 16 monomer units. Telomers containing up to about 16 monomer units are distillable at reduced pressures of the

order of 1 to 0.1 mm. of mercury, the longest of these telomers distilling, at the reduced pressure, at a temperature of about 250 C. Telomers of longer chain length are not readily distillable in that they require higher temperatures at which substantial decomposition begins to take place. For optimum surface active properties and for optimum compatibility with perhalogen ated polymers, it is desirable that the carboxylic compounds of this invention have a chain length of at least 6 carbon atoms. In other words, the preferred carboxylic compounds are those wherein n is an integer from 3 to 16, or those having a chain length of from 6 to 32 carbon atoms with sulfuryl halide telogens, and from 7 to 33 carbon atoms with bromoperhalomethane telogens. The telomers suitable as starting material for the purpose of this invention are prepared, as stated above, by directly polymerizing the fluoroethylene monomer in the presence of a catalyst and one of the above-mentioned telogem. The yield cf telomer of desired chain length will vary witch the relative ratio of telogen to monomer with higher ratios producing a predominance of low molecular weight material, and lower ratios producing a predominance of high molecular weight material. In general, telomers produced bv any mole ratio of telogen to olefin from about 1 to 5 to about 3 to 1 may be used. To produce a high yield of telomer containing from 3 to 16 monomeric units, it is preferred that the telogen to olefin ratio be about 1 to 1. Catalysts other than benzoyl peroxide, such as di-t-butyl peroxide or dichlorobenzoyl per oxide, may be employed. Favorable results are obtained by using 1% by weight benzoyl peroxide based on the monomer. Inert solvents may or may not be present in the telomerization process. An inert solvent is any liquid winch does not materially alter the normal polymerization of the Zuoroethy- lenic compound in the presence of the sulfuryl halide or bromoperhalomethane. Carbon tetrachloride and tetrachioroethylene are examples of such solvents. It is to be noted that carbon tetrachioride is itself a telogen, considerably less eXective than, for example, bromotrichlorometuane or sulfuryl chloride, and may, therefore, be regarded as substantially inert. The telomers described above are hydrolyzed to the corresponding carboxylic acids by treatment with concentrated sulfuric acid contanning sulfur trioxide at elevated temperatures. By controlling the temperature, duration d treatment and concentration of the fuming sulfuric acid, monoacids and/or diacids are produced. In general, the lower concentrations of fuming sulfuric acid (containing about to 20% SO,, for example); lower temperatures (between about 140 C. and about 21 C.) and shorter reaction time (5 to

25 hours), are sufficient to hydrolyze the ClE7GI2 group or CFClBr group to CC OH, the diacid being formed in lower yield, if at all, under such conditions. It is not necessary to operate at the highest extreme of temperature and the highest extreme of SO3 concentration at the same time in order to obtain good yields of diacid. Actually, in a practical sense, one is ordinarily limited to the equilibrium concentration of SO, in fuming sulfuric acid for any particular temperatuxe of operation. Thus, it may be necessary to sacrifice high SO, concentration in order to achieve high operating temperature, and vice versa. The optimum combination of conditions for producing high yields of diacids is about 5 to 10% fuming sulfuric acid at 230 to 250" C. It is possible, of course, to increase the equilibrium concentration of SO, in fuming sulfuric acid at a particular temperature by increasing the pressure on the system. How- ever, volatile inorganic materials are by-products of this reaction and have, at any particular temperature, a much higher vapor pressure than SO,. Consequently, any increase in the total pressure of the system is primarily taken up by the partial pressure of these volatile gases and produces comparatively little effect with respect to the partial pressure of so3. It is also desirable to operate in an increased pressure system when dealing with a low molecular weight telomer, such as the dimer Cl-(CF2CFCl)2-Cl, which has a boiling point of 135 C. Under increased pressure the dimer is maintained in the liquid phase at higher temperatures. The reaction is conveniently carried out in a glass or preferably in a metal vessel equipped with a thermometer, stirrer and reflux condenser, the latter being fitted with a tube leading to a vessel containing water or basic solution. The latter device is necessary to trap the SO, fumes and any other vapors evolved during the course of the reaction. The hydrolysis may be conducted under an atmosphere of nitrogen or other inert gas. Upon completion of the reaction, the reaction mixture is cooled and poured over ice, and the organic material isolated by ether extraction of this aqueous mixture. Any unreacted starting material may be separated from the acidic product by subjection of the ether extract to distillation under reduced pressure. An alternative procedure is to basify the aqueous mixture with a basic reagent such as sodium hydroxide, followed by ether extraction to remove the non-acidic starting material. The basic mixture is then reacidifled with Ha SO4 and ether extracted. Subjection of the concentrated ether extract to distillation under reduced pressure will yield the acidic product, which if solid, may be

further purified by crystallization and/or redistilled. Other organic solvents which may be used to extract the organic material from the aqueous mixture are carbon tetrachloride; chloroform; methylene chloride; 1,1,2-trichloro-1,2,2-trifluoroethane, etc. The acids have been characterised by conventional means, such as by preparation of various salts and esters and by the determination of their neutralization equivalents, boiling points, melting point, surface tension and by chemical analysis. A more advantageous method of isolating the desired carboxylic acids involves direct extraction of the reaction product with a lovr-boiling organic solvent which is insoluble in fuming sulfuric acid. Among the solvents which may be used are methylene chloride, 1,2,2-trichloro-1,1,2-trifluoroethme (Freon 113), carbon tetrachioride, chloroform, l,l-dichloro- ethane, trichlorofluoromethane, 1,1,1,-trichioroethane and others. The word " Freon" is a Registered Trade Mark. The advantages of this latter method lie in eliminating the necessity of treating large volumes of fuming sulfuric acid with water and in permitting the reuse of the fuming sulfuric acid. The method also permits the use of vessels made of materials (e.g., carbon steel) which are resistant to anhydrous sulfuric acid, but not to dilute sulfuric acid. The extract is washed with 25% HC1 to remove sulfuric acid and then distilled, with the solvent coming off as the first fraction. Under the conditions of the fuming sulfuric acid treatment, some formation of acid anhydrides may occur. The dicarboxylic 5 car bon acid readily forms a cyclic anhydride, while monocarboxylic acids may combine to produce acyclic anhydrides of higher molecular weight. Despite their higher molecular weight, the acyclic anhydrides are lower-boiling than the monocarboxylic acids from which they are derived, since the acids are strong acids and highly polar compounds and since the loss of polarity has a greater elect on boiling point than molecular weight increase. The cyclic anhydride is, of course, lower-boiling than the diacid from which it is formed since both the polarity and the molecular weight are decreased. These anhydrides are readily converted to the acids from which they are derived by the addition of water. On the other hand, the acids may, if desired, be converted to anhydrides by reaction with SO, or P2O5. In some cases, particularly when the telomers produced have relatively inactive end groups having a high fluorine content, it may be desirable to convert the fluorine-containing end group to-one which is more easily hydrolyzed. The reaction of a sulfuryl chloride telomer of

chlorotrifluoroethylene, for example, requires rather drastic conditions, including high temperatures, high concentrations of SO, in the fuming sulfuric acid, and relatively long periods of reaction. These rather drastic conditions are required because of the relative inactivity of the CFCl2 end group of this telomer. The reaction of the sulfuryl chloride telomer of tetrafluoroethylene requires even more drastic conditions, since it produces a CF2Cl end group which is even less reactive. Since the reaction of the aforesaid telomers with fuming sulfuric acid generally takes place in a system involving two liquid phases, the reaction period may be extremely extended when large volumes of reactants are involved, since the reaction takes place primarily at the interface between the phases. It has been found that perhalogenated telomers containing a fluorine atom in an end group may be reacted with a chloride or bromide of a metal having a valence of at least 3 to convert the fluorine-:ontaining end group to a halogenated end group which can be hydrolyzed more easily than the fluorine-contaming end group. For example, the telomers produced by telomerization with sulfuryl halides may be designated as Qn(CF2CXaXb)nQbwherein Xa and Xb) Qa and Qb are halogen atoms selected from chlorine and fluorine, and n is an integer between 2 and 16. These telomers, when reacted with a chloride or bromide of a metal having a valence of at least 3, react at either the Qb end or at both ends to produce novel perhalo alkanes of the formula Za(CXaX@ CFa)n-1Ze, wherein X@ and X5 are halogen atoms selected from fluorine and chlorine, Za is a perhalomethyl radical of the group consisting of chlorodifluoromethyl, tr;-fiuoro- methyl, trichloromethyl and tribromomethyl radicals, Zc is a perhalomethyl radical of the group consisting of trichloromethyl and tribremomethyl radicals, and Xc Xi, and n are defined as above. The telomers produced from the aforesaid monomers by telomerization with the telogen sulfuryl chloride, may be designated as Cl(CF2CXaX@)nCl wherein X1, Xb and n are defined as above. Such telomers, when reacted with aluminum chloride, under conditions which are preferable for converting one end of the telomer molecule, produce novel fluoroperhalo alkanes having the formula CF2Cl (CXaXbCF2)n-1CCl3 wherein Xa, XL and n are defined as above. The telomers produced irom chlorotrifluoroethylene with any of the aforementioned sulfuryl halides may be defined as having a formula Yd(CF2CFCl)nY@ wherein Yd and Y@ are halogen atoms selected from chlorine and fluorine atoms, and n is an integer from 1 to 16. Such telomers, when reacted with a metal chloride or bromide, under

conditions for the preferable conversion of one end of the molecule, produce novel fluoroperhalo alkanes having the formula CF2Yd(CFClCF2)n-1CCl2Y@ wherein Yf is a halogen atom selected from chlorine and bromine, and Yd and n are defined as above. The - telomers produced by the telomerization of chlorotrifluoroethylene with sulfuryl chloride may be designated as C1(CF,CF ClDnC1, wherein n is an integer from 2 to 16. Such telomers, when reacted with aluminum chloride under conditions which are preferable for converting one end of the molecule, produce novel fluoroperhalo alkanes of the formula Cl(CF2CFCl -CF2CCl, wherein iz is defined as above. When reacted with aluminum chloride under conditions preferable for converting both ends of the molecule, such telomers will produce novel fluoroperhalo alkanes of the formula CCl,(CFCl CF2)n-1-CCl3. Similarly, the telomers produced by telomerization with bromoperhalomethanes have at least one bromine-containing end group consisting of CBrClF or CBrF., and an opposite end group consisting of CF@, CClF@ CCl@F. CBrP2 or CBrClF. These end groups, except for the CF, end group, may be converted to CCI,, CCl2Br, CBr2Cl, and C1r, end groups, depending on the nature of the monomeric unit, the nature of the broinoperhalomethane telogen, and on whether the halogen of the methyl halide is chlorine or bromine. The pre@erred metal halide is aluminum chloride; however, other chlorides and bromides of metals having a valence of at least 3 may be used, such as FeCl, AlBra, TiCl5, SbCl@, RCl@ SnCl, and others, In general, these metal halides may C be described as the Friedel-Crafts type catalysts, containing chlorine or bromine as the halogen atoms. A sulfuryl chloride telomer of chlorotri- fluorcethylene, having the formula Cl(CF2CF Cl)nCl may be converted to its chlorinated derivative Cl(CF2CFCl)n-1CF2CCl3 by treatment with aluminum chloride at a temperature ranging from about 0 C. to about 125 G in the presence or absence of a solvent. The telomer and the halogen exchange reagent may be admixed at room temperature or below, followed by careful and gradual warming d the mixture until appreciable reaction is observed. The reaction is an exothermic one, and once it starts, external cooling' may be necessary in order to keep the reaction te nperature below about 85 C. In view of the exothermic nature of the reaction, it is preferable to add the telomer portionwise to the halogen exchange reagent (or vice verse) over an extended period of time while carefully observing and controlling the temperature during the addition.

The concentration of aluminum chloride to telomer may vary over a wide range, such as from about 0.1 to about 10 molar excess. How- ever, use of more than about a 1.5 molar excess of aluminum chloride is merely wasteful of this reagent and does not facilitate the reaction. The preferable concentration is from about 0.2 mole of halogen excllange reagent to about 1.5 moles per mole of telomer. Any organic liquid which is inert to the reactants under the reaction conditions may be used to dissolve or suspend the starting compounds. The preferable type solvents being the liquid hydrocarbons, such as n-heptane, cyclohexane, petroleum ether; the halogenated hydrocarbons, such as carbon tetrachloride, methylene chloride, chloroform, etc. Upon completion of the reaction, the excess aluminum chloride is hydrolyzed in the usual manner, i.e., by treating the reaction mixture with ice and hydrochloric acid. The organic compounds may be separated by extraction of the aqueous layer with a suitable solvent, such as ether or carbon tetrachloride, removal of the solvent to yield the organic extract. An alternate procedure is to subject the hydrolyzed mixture to steam distillation, the steam distillate containing the organic compounds. The organic ether extract, or the organic layer of the steam distillate is then distilled under reduced pressure to remove any unreacted starting material and to isolate the R-CCl, compounds. The R-CCl compounds have been characterized by chemical analysis, boiling point, index of refraction, density and molar refractivity. CF2Cl end groups require somewhat higher temperatures for conversion to CCl3, as, for example, temperatures between about 100 C. and 150 C. Time of reaction, concentration, and nature of the metal halide, and other variables will affect these conditions. Such conditions are used when treating telomers containing such end groups as the more readily hydrolyzable end groups, or when it is desired to convert both end groups of the molecule. One of the chief advantages of the fluoroparhalo alkanes prepared in accordance -sith the above procedure over the perfluoroalkanes and fluoroperchloro alkanes derived from the telomerization of a perhalogenated olefin in the presence of a sulfuryl halide telogen, lies in the reactivity of the end group produced, and in the fact that they may be hydrolyzed easily with concentrated sulfuric acid containing SO,. In general, milder conditions may be used for the hydrolysis of end groups containing no fluorine atoms, so that the concentration of excess SO, may range from substantially to about 30 per cent by weight of the sulfuric acid, and the temperatures may range from about 125 C. to about 200 C. The hydrolysis is usually complete within about 30 hours.

Carboxylic acids, both monoacids and diacids, produced by this invention, are strong acids and react readily with alkali metal, alkaline earth and other metal hydroxides, carbonates and other basic compounds, to produce corresponding metal salts. The acids also react with gaseous ammonia or with ammonium hydroxide to produce ammonium salts. Metal and ammonium salts of the monocarboxylic acids containing at least 6 carbon atoms are particularly useful as emulsifying agents in the emulsion polymerization of perhalo polymers. The acids of this invention are thermally stable at temperatures of 200 C. and above Both the acids and the salts are useful as surface active agents and can be used in highly acid and/or highly corrosive environments, as, for example, in electroplating baths and in sulfuric acid storage batteries. Esters of the foregoing carboxylic acids are alsc easily prepared by usual esterification methods involving the reaction of the monoacid or diacid with an alcohol and the removal of water therefrom. Water may be removed by the presence of a water removal agent, such as concentrated sulfuric acid, or preferably may be removed by continuous distillation during the esterification reaction. Esters of the mono acids are particularly useful as softening agents for perhalogenated polymers, and esters of the diacids with poly alcohols form long chain highly halogenated polymers with advantageous properties. EXAMPLE 1. (a) HYDROLYSIS OF CCl3-(CF2CFCl)2Br TO CCl3-CF2-CFCl-CF2-COOH A stirred mixture of 108 grams (0.25 mole) of CCl,(CF2CFCl)2Br (b.p. 118 /20 mm.) and 130 ral. of fuming sulfuric acid (20% SO,) was heated to 1301400 C. for 10 hours in a reaction flask fitted with a mechanical stirrer. Bromine and acid vapors were evolved during the 10 hours after which time the homogeneous mixture was poured onto 1000 grams of ice. The pH of the solution was adjusted to pH 10 with sodium hydroxide solution and 9 grams of non-acidic starting material were recovered by ether extraction. The basic solution was concentrated to about 1900 ml., reacidified with concentrated sulfuric acid, and extracted with ether for 7 days in a continuous extractor. Concentration of the ether extract yielded 61 grams (80% yield) of product oil. distillation of the oil at reduced pressures yielded a total of 49.5 grams of acidic material with the following characteristics: Fraction Boiling point P Wt. Solubility in NaOH (1) 44-126 C. 21 mm. 0.5 grams oil partly soluble (2) 126- 39 20 " 6 " " soluble (3) 139- 47 20 " 15.5 " " "

(4) 147- 57 20 " 10.5 " " " (5) 151- 60 20 " 6 " " " (6) 151- 60 20 " 11 crystallized " 49.5 (b) HYDROLYSIS OF CCl3(CF2-CFCl)@Br Hydrolysis of 453 grams (1.05 moles) CCl3(CF2-CFCl)2Br (b.p. 115-130 C./20 mm.) was effected by heating this halocarbon with 100 ml. of 65% fuming sulfuric acid and 215 ml. of concentrated sulfuric acid under a nitrogen atmosphere at 160 C. for 23 hours. The reaction roiture was poured onto ice and ether extracted to yield 109 grams of product, soluble in sodium hydroxide solution and with the following boiling points and neutralization equivalents: Fraction Wt Gbserved N.E. (1) 100/130 C/0.5 mm 60 gms. (2) 130-145 C./0.5 mm. 49 gms. 139 Calculated N.E. - HOOC-CF2-CFCl-CF2-COOH=128 CCl3-CF2-CFCl-CF2-COOH=330 From the neutralization equivalent it was apparent that fraction (2j was primarily the diacid 3-choropentafluorogluraric acid. (c) PREPARATION OF LEAD SALT OF HYD ROLYSIS PRODUCT OF CCl2(CF2CFCl)2Br One gram of the hydrolysis product of CCl3(CF2CFCl)2Br (fraction 3 of Example 1a, b.p. 139-47 C./20 mm.) was stirred with water and excess lead carbonate. The excess carbonate was then removed by filtration and the water soluble salt (1.05 grams) obtaiiThy evaporation of the water. (d) PREPARATION OF GALCTUM SALT OF HYD ROLYSIS PRODUCT OF CCl3(CF2CFCl)2Br The calcium salt of the hydrolysis product of CCl3-(CF2CFCl)2-Br (fraction 3 of Example 1a) was prepared in the same way as described in ic above, except that an excess of calcium carbonate was used. EXAMPLE 2. HYDROLYSIS OF CCl3-(CF3-CFCl)3Br TO HOOC-(CF2CFCl)2-CF2-COOH The hydrolysis of 400 grams of (0.73 mole) of CCl3-(CF2-CFCl)3Br (b.p. 146-48 C./ 10 mm.) was effected by heating with 100 ml. of 65% fuming sulfuric acid and 215 ml. of concentrated sulfuric acid under an atmosphere of nitrogen to 160O C. for 25 hours. The alkali soluble product (261 grams corresponding to a yield of 96%), isolated as described in the above example, boiled at 145-165 C./0.2 mm. The product is identified as HOOC(CF2CFCl),-CF2-COOH (3,5-dichloro- octafluoropimelic acidj by analysis for chlorine and fluorine content and by its neutralization equivalent.

Calculated for C7H2O4Cl2F8:Cl, 19.00; F, 40.75; N.E. 186 Found :Cl, 18.94, F, 41.09; N.E. 196 EXAMPLE 3. HYDROLYSIS OF PREDOMINANTLY C7 AND C9 FRACTION Oil (635 grams) obtained from the teiomemzation of chlorotrifluoroethylene with bromotrichloromethane (distilled fraction, b.p. 85120 C./0.5 mm.) was hydrolyzed with 500 ml. of 20% fuming sulfuric acid under a nitrogen atmosphere by heating to 180-190 G for 48 hours until bromine evolution was no longer observed. The solution was then homogeneous and was cooled, poured onto ice and the aqueous solution separated from the inscluble organic material and ether extracted. The concentrated ether extract and organic material were combined and distilled in vacuo to obtain the following alkali soluble fractions:- Fraction Boiling point Weight (g) Observed N.E. (1) 150-160 C./0.4 mm. 43.3 202 (2) 160/0.4-170-.1 mm. 167 158 (3) 170/0.1-185/0.2 mm. 133 193 (4) 182/0.2-205/0.1 mm. 105 243 448.3 grams Calculated N.E.'s HOOC-(CF2-CFCl)3-CF2-COOH=245 (N.E. of C9 monoacid =563) HOOC-(CF2-CFCl)2-CF2-COOH=186 (N.E. of C7 monoacid= 446) Fraction (4) was identified as the Ca diacid 3,5,7-trichloroundecafluoroazelaic acid while the lower fractions appeared to be primarily mixtures of diacids. EXAMPLE 4. HYDROLYSIS OF PREDOMINANTLY C11 AND C13 FRACTION Oil (610 grams) obtained from the telomerization of chlorotrifluoroethylene with brorno- trichloromethane (distilled fraction, b.p. 100170 C./0.1 mm.) was hydrolyzed with 500 ml. of 20% fuming sulfuric acid under a nitrogen atmosphere by heating to 190-210 C. for 40 hours. A total yield of 415 grams of acidic product, insoluble in methylene chloride, was obtained. The neutralization equivalent was found to be equal to 294. Calculated N.E.'s:HOOC-(CF2-CFCl)4-CF2-COOH=303 HOOC-(CF2-CFCl)3-CF2-COOH=360 EXAMPLE 5. HYDROLYSIS OF CCl3(CF2-CFCl)2Br TO ACID ANHYDRIDE A mixture of CCl3(CF2-CFCl)2Br (431 grams) and 10% fuming sulfuric

acid (400 ml.) was heated with stirring to 140 for 36 hours. The product was distilled directly from the reaction flask and redistilled through an 18 inch helical column. 190 grams (80%) of diacid anhydride, b.p. 102-102.5 was obtained. N.E. Cl F M.R. nd20 d2525 Calculated for 3-chloro- pentafluoro - glutaric anhydride: 119.2 14.86 39.79 30.3 Found: 118.5 14.94 41.10 31.1 1.3630 1.704 An additional 12% yield was obtained by extraction of the sulfuric acid layer with CF2Cl-CFCl2. Total yield 92%. EXAMPLE 6. HYDROLYSIS OF CCl,(CF2-CFCl)1Br A mixture of CCl,(CF2-CFCl)2Br (442 grams; 1.02 mole) and 400 ml. of absolute (100%) sulfuric acid was heated to 125 C. for 24 hours with stirring. Red fumes were evolved throughout the reaction. The cooled two-phase mixture was diluted with 150 ml. of water, and extracted with CF2-Cl-CFCl2. The product was decolorized with saturated sodium bisulfite solution, concentrated and distilled through an 18 inch spiral column. 40 grams of a liquid boiling at 8090 C. at 20 mm, was identified as 3,5,5,5-tetrachloropentafiuorovaleric anhydride (CCl3-CF2CFCl-CF2-COO),O. nd20=1.4205 d2020=1.94 N.E.=321 (calc.) 284 (found) M.R.=84.7 (calc.) 84.3 (found) The anhydride structure was confirmed by Infra Red analysis. EXAMPLE 7. HYDROLYSIS OF TRIMER, Cl-(CF2CFCl)3-Cl TO Cl-(CF2-CFCl)2-CF2-COOH(3,5, 6, TRICHLOROOCTAFLUOROCAPROIC ACID) A mixture of 0.3 mole of Cl-(CF,-CF Cl),-Cl (b.p. 203 C., d=1.82) and 150 ml. of 10% fuming sulfuric acid was heated to reflux with stirring for 36 hours. The homogeneous reaction mixture was then added to ice, made basic and steam distilled to remove starting material (3 ml. of trimer were recovered). The mixture was then reacidified and continuously extracted with ether for 48 hours. The ether extract was concentrated and distilled to yield 59.4 grams (54% yield) of water soluble acid boiling at 132-135 C./20 i. and having the following

characteristics: Observed neutralization equivalent: 376 Calculated neutralization equivalent: 365 for Cl-(CF2-CFCl)2-CF2-COOH Observed molecular weight: 359 (determined in acetic acid) Calculated molecular weight: 365 for Cl-(CF2-CFCl)2-CF2-COOH EXAMPLE 8. HYDROLYSIS OF TETRAMER, Cl(CF2CFCl)4Cl TO MONOACID, Cl(CF,CFCl), CF2-COOH (3,5,7,8 TETRACHLOROUNDECAFLUOROCAPRY LIC ACID) AND DIACIDS, HOOC-CFCl (CF2-CFCl)2-CF2-COOH (2,4,6 TRI CHLORONONAFLUOROSUBERIC ACID AND HOOC-CF2(CF2-CFCl)2-CF2-COOH (3,5 DICHLORODECAFLUOROSUBERIC ACID) (a) A mixture containing 161 grams (0.3 mole, 87 mi.) of Cl(CF2CFCl)4C1 (b.p. 125/ 10 mm.) and 200 ml. of 20% fuming sulfuric acid was heated with stirring at reflux temperature (230-240 C.) for 46 hours. The mixture, on cooling, separated slowly into two layers. The upper layer which was mostly sulfuric acid was added to ice and neutralized with sodium hydroxide; steam distillation of the basic solution gave only a trace of unreacted starting material. The viscous lower layer was diluted with carbon tetrachloride, washed with 25% hydrochloric acid and distilled to yield 85 grams (50% yield) of acidic material boiling mainly at 150-160 C./ 10 mm. The main fraction (56.6 grams) had the following properties : - Boiling point: 154-156.5 C/10 mm. Index of refraction (nD20): 1.3980 Density (d20): 1.899 Molar refractivity: Observed: 60.8 (calcu lated M.R. for monoacid=59.83). Neutralization equivalent: Observed: 492 (Calculated N.E. of monoacid is 479.9). Analysis: Calculated for C8F11Cl1O2H: Cl, 29.50%; F, 43.55%. Found: Cl, 28.90%; F, 41.02%. Thus, the product acid is identified as having the structure Cl(CF2-CFCl)3-CF2 COOH. (6.2 grams of a fraction boiling at 159168 C./10 mm. was also obtained with nD20=1.3970-17). (b) REUSE OF SULFURIC ACID LAYER Tetramer (161 grams, 86 ml. 0.3 mole) was refluxed for 24 hours with a mixture of 100 ml. of 20% fuming sulfuric acid and 92.5 ml. of concentrated sulfuric acid (approximately 100% H2SO). On cooling, the

lower organic layer was withdrawn and the upper sulfuric acid layer re-used under similar conditions with second and third 86 ml. portions of tetramer. The organic layer was steam distilled to remove unreacted tetramer. The steam distillation residue (79.6 grams) was diluted with methylene chloride, the solution was washed with dilute hydrochloric acid, the methylene chloride distilled and the crude residual acidic product distilled at reduced pressures. The main portion boiler at 150162 C./10 mm. and was identified as the monoacid, Cl(CF2CFCl)3CF2-COOH; a second fraction boiling at 140-160 C./1 mm. was collected and found to consist chiefly of the tetramer diacid by determination of its neutralization equivalent as 230 (calculated N.E. for HOOC-CFCl-(CE0-CECI), CF-COOH is 220 and for HOOC-CF, (CF2-CFCl),-CF,-COOH is 212). Analysis of fraction, b.p. 140-160 C./l mm.: Calculated for C8O4H2F9Cl3:Cl, 24.9; F, 38.90,G for C8O4H2F10Cl2:Cl, 16.8; F, 45.0% Found (first sample) :Cl, 18.40; F, 41.40 (second sample): Cl, 17.70; F, 44.34 (No sulfur content) From the empirical analysis it was apparent that most, if not all, of the diacid had 2 rather than 3 chlorine atoms and therefore was HOOC-CF-(CF-CFCl), - CF COOH. EXAMPLE 9. AUTOCLAVE HYDROLYSIS OF TETRAMER TO MONOACID AND DIACIDS A mixture of Cl-(CF2-CFCl)-Cl(2M) and 1 litre of 8% fuming sulfuric acid was charged to a stainless steel autoclave fitted with a vent pipe through the ceiling. The mix ture was heated to 230 C. for 29 hours with stirring. The autoclave was discharged by use of an evacuated flask and a piece of bent glass tubing. Material still remaining in the autoclave was washed out with water. The organic phase which was separated rather difficultly, because of a suspended brown solid, was distilled directly. The sulfuric acid layer was added to ice, combined with the autoclave washings and extracted with ether for three days. The extracted material was filtered and distilled. Yields:Cl-(CF,-CFCI)4-Cl 0 CF,Cl(CFCl-CF2),-COOH 646 g. 67.3% HOOC(CFCl-CF2)3-COOH and HOOC-CF2(CF2CFCl)2- CF-COOH 156 g. 18% Total yield (mono+diacids)=85% Infrared analysis showed both the original organic phase and distilled acid fractions to contain carboxyl groups, but no carboxylic

anhydride. Boiling point of C8-diacids=182 C/5 mm Observed N.E.=230 (calculated N.E.=220 for alpha CFCl 212 for alpha CF2) A sample of material collected from high boiling fractions from several Cl(CF2- CFCl)4C1 hydrolyses was redistilled. 100 grams of a fraction boiling 135-156 C/0.8 mm. was obtained, having a neutral equivalent of . 229. N.E. calculated for HOOC-(CFCl- CF2)2-COOH=220; for HOOC-CF2- (CF,-CFCl)- CF2-COOH=212. EXAMPLE 10. HYDROLYSIS OF PREDOMINANTLY C,2 FRAC TION OF SULFURYL CHLORIDE TELOMER OIL (a) A distilled mixture containing 907 grams of sulfuryl chloride telomer oil (boiling point: 65-100 C./0.1 mm.), 48/ ml. concentrated H2SO4 and 520 ml. of 20% fuming sulfuric acid was hydrolyzed at about 230 C. for 30 hours. Upon completion of the reaction, the mixture was made basic with sodium hydroxide and extracted with hexane to remove starting material (only a trace was recovered). The basic solution was then acidified with sulfuric acid and continuously extracted with ether. Concentration of the ether solution yielded 586 grams of extract which was diluted with methylene chloride, filtered, washed with a 1:1 aqueous solution of hydrochloric acid and distilled to yield the following alkali soluble products:- Boiling point Weight 116 C./1.0 mm.-1400 C./0.7mm. - - 193.1 -157 C./0.8 mm. - - 190.8 -170 C./0.7 mm. - - 95.6 479.5 grams (b) A 212 gram portion of crude acid, prepared from the aforesaid fraction of sulfuryl chloride telomer oil under conditions similar to those described in Example 4a, was subjected to distillation under reduced pressure to yield the following fractions: Boiling point Weight N.E. (1) 87/.04-114' C./0.8 mm. 41.7 grams 462 (2) 111/0.03-136/0.08 mm. 58.7 grams 380 (3) -140 C./0.08 mm. 19.1 grams 323 The three fractions were soluble in a 5% aqueous sodium hydroxide solution. Ass Boiling point, C./mm. Weight Solubility in Solubility in N.E. 5% NaOH Soln. Water (1) 86/.1-87/0.07 34.9 mostly soluble partly soluble 1310 (2) - 102/0.02 52.7 soluble (foams) swells or foams 1010 (3) -115/0.05 23.3 soluble or swells or foams 707 swells (foams) (4) -122/0.04 47.1 soluble or swells or foams 595 (5) trace swells (foams)

158.0 grams By assuming Cl(CF2-CFCl)6Cl to represent the average molecular weight in the distilled telomer fraction, the combined fractions (158.0 grams) represent a 90% yield of C12-acid. Cl(CF2-CFCl)6ClMW-770 770 =1.06 Cl(CF2-CFCl)3CF2COOH=713 713 158x1.06 =90% yield (assuming all 4 fractions to be acid) 186 EXAMPLE 11. HYDROLYSIS OF HIGHER BOILING TELOMER FRACTIONS TO ACID PRODUCTS A mixture of 180 grams of sulfuryl chloridechlorotrifluoroethylene telomer oil (boiling point 135-170 C./0.1 mm.; specific gravity= 1.91 at 38 C.) and 200 ml. of 20% fuming sulfuric acid was heated to reflux (about 230 C.) for 12 hours. The separated organic layer was washed with water, the water extracted with ether and the whole distilled to yield four fractions with the following properties: Neutralization Fraction, C. /mm Weight (g.) Solubility S % NaOH equivalent (1) 121/0.3-121/0.1 48.1 partly 1850 (2) 121/0.1-127/0.09 51.2 partly 1800 (3) 127/0.09-140/0.07 43.6 reacts hot 1260 (4) 140/0.07-158/0.09 10.9 reacts hot 980 The N.E.'s of (1) and (2) are high because of unreacted starting material. EXAMPLE 12. PREPARATION OF CF2Cl(CFCl-CF)4COOH, HOOC(CF2CFCl)3CF2CF2COOH AND HOOC(CF2-CFCl)4 COOH A mixture of Cl(CF2-CFCl)3Cl (640 g., 0.98 mole) and 500 ml. of 10% fuming sul furic acid was heated to 215 C. with stirring for 42 hours. The product was isolated by extracting the crude reaction mixture with 1,1,2-trichloro-1,2,2-trifluoroethane for 48 hours. The extract was washed with 25 ,o HCl, concentrated and distilled through an 18" heated jacket, spiral column. A 95% yield of acids was obtained after recovery of 69 grams of unreacted Cl(CF2-CFCl)5Cl. Neutral Equivalent b.p. calc. found CF2Cl(CFCl(CFCl-CF2)4COOH 124-126 /0.2mm. 596 594 HOOC(CF2-CFCl)4COOH 155-159 /0.06 mm. 278 269 HOOC(CF2-CFCl)3-CF2-CF2-COOH 270

EXAMPLE 13. PREPARATION OF HOOC(CF2-CFCl)3 COOH AND HOOC(CF2CFCl)2CF2CF2COOH A mixture of Cl(CF2-CFCl)4Cl (537 grams, 1 mole) and 500 ml. of 10l, fuming sulfuric acid was heated with stirring to 230250 C. for 50 hours. The product was worked up as above, giving a 75% yield of HOOC(CF2-CFCl)3COOH and HOOC (CF3CFCl)2CF2CF2COOH, b.p. 125-127 / 0.1 mm. Neutral equivalent: 223; calculated 220 and 212 respectively. No monoacid was isolated. EXAMPLE 14. PREPARATION OF CF2Cl(CFCl-CF2)2COOH A mixture of Cl(CF2-CFCl)3Cl (1720 grams,4.1 mole) and 2050 ml. of 10% fuming sulfuric acid was heated with stirring to 205 C. for 42 hours in a stainless steel autoclave filled with a vent pipe. The discharged product was extracted with CF2Cl-CFCl2 for 24 hours and the extract washed with 25% HCl and distilled. A 78% yield of CF2Cl(CFCl- CF2)2COOH, b.p. 105-6 /5 mm. was obtained. xD20 1.3903; d2020 1.860; M.R. calc., 46.5; found, 46.4. In similar reactions the vent pipe was replaced with a laboratory liquid-liquid extractor and the product extracted directly from the autoclave with CF2Cl-CFCl2 or CH2Cl2. EXAMPLE 15. REACTION OF Cl(CF2-CFCl)3-Cl WITH ALUMINUM CHLORIDE (a) A mixture of 252.0 grams (0.6 mole, 139 ml.) of Cl(CF2-CFCl)3-Cl (b.p. 203 , d= 1.82) and 80 grams (0.6 mole of anhydrous aluminum chloride was carefully heated with stirring for about 3.5 hours, maintaining the temperature at about 90 C. Ice and hdyrochloric acid were added and the product isolated in the usual manner as described in the above examples. Distillation of the reaction product at reduced pressures gave a 64% yield (166.2 grams) of total product, the various fractions boiling at: Boiling point Weight nD20 fl,020 MR* 119.5-121 C./20 mm. 54.5 grams 1.4211-17 18.70 59.3 121 C./20 mm. 54.1. " 1.4211-17 1.87 59.3 121-123.5/20 mm. 57.6 " 1.4219-17 *Assuming molecular weight to be 437(C6Cl6F8) or Cl(CF,CFCl)2CF2CCI, the cal culated molar refractivity is 59.38. (b) WITH CARBON TETRACHLORIDE AS SOLVENT To a stirred, refluxing mixture of 80 grams (0.6 mole) of anhydrous aluminum chloride and 150 ml. of carbon tetrachloride was added 252

grams (0.6 mole) of trimer, Cl(CF2CFCl)3Cl. After 19 hours of reflux the mixture was cooled, hydrolyzed with dilute hydrochloric acid and steam distilled. Distillation of the distillate through an 18 inch spiral column gave 0.3 mole (50% yield) of CF2Cl(CFCl-CF2)2- CCi, (1,1,1,3,5,6 hexachlorooctafluorohexane), b.p. 118-22/20 mm. and 0.07 mole (11% yield based on C6(Cl7F7) of a liquid boiling 144-7/20 mm. the molar refractivity calculated for CGCI7F7 is 63.5, found was 65.0. The remainder of the product was a dark residue, presumably of higher chlorine content. HYDROLYSIS OF ClCF2-(CFCl-CF2)2 CCl3 TO ClCF2(CFCl-CF3)2-COOH A mixture containing 186 grams (0.43 moles, 100 ml.) ClCF2-(CFCl-CF2)2-CCl3 (b.p. 118-122 C./20 mm., d20=1.873), prepared as described above, and 200 ml. of 20% fuming sulfuric acid was heated with stirring to about 1500 C. for 20 hours after which time the solution was homogeneous. After cooling the mixture was extracted four times with 100 ml. portions of carbon tetrachloride and then continuously extracted with carbon tetrachloride. The extracted residues were combined and distilled to yield the following fractions: Neutraliza- Index of tion refraction Specific Boiling point Weight g. equivalent n,,20 gravity (1) 69-74 C./40 mm. 37.14 - 1.4201-18 1.769 (2) 74 C/40 mm.-174 C./20 mm. 23.19 - 1.4056-17 1.823 (3) 151-161 C./10 mm. 58.80 355.0 1.3907-17 1.857 (4) 162-164 C./10 mm. 37.65 357.8 1.3912-17 1.840 A total of 96.5 grams (fractions 3 and 4) of acidic product was obtained. It is assumed that the main product of fraction (3) is the monoacid, ClCF2-(CF2-CFCl)2-COOH (calculated N.E. for this C6-acid is 363.4). What we claim is:- 1. Fluoroperhalogenated carboxylic acids having the generic formula Z(CF2CFCl)n-2 CF2COOH, wherin Z is a monofunctional radical of the group consisting of Y,CF, CFCl-3 YbCF2CFCl-, HOOC OF2CFCl-, HOOC CFCl- and HOOC CF2- radicals, Ya in the first mentioned radical of said group being a perhalomethyl radical having a total atomic weight of not higher than 146.5 and Yb in the second mentioned radical of said group being a halogen atom selected from the group consisting of fluorine, chlorine and bromine atoms, and wherein n is an integer from 1 to 16.

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