Indian Journal of Fibre & Textile ResearchVol. 19, March 1994, pp. 22-29

Pigment printing o!fcotton with methacrylic acid-based synthetic thickeners

R B Chavan, P Bajaja & Meenakshi GoyalDepartment of Textile Technology, Indian Institute of Technology, New Delhi 110016, India

Received 11 June 1993; revised received 13 September 1993; accepted 28 October 1993

Methacrylic acid (MAA) - ethyl acrylate (EA) - ethylene glycol dimethacrylate (EGDM)/N~'-methylene bisacrylamide (MBAM) polymers of different compositions were used as synthetic thickenersin pigment printing of cotton. Crosslinked polymers with different feed ratios were synthesized and theirprinting behaviour was compared with the conventional kerosene emulsion thickener and a commer-cial synthetic thickener Alcoprint PTF in terms of colour value, back penetration, wash, rub (dryand wet) and scrub fastness, and handle of the fabric. Methacrylic acid-based thickeners (solid con-tent 4%), when used as a substitute of kerosene emulsion, produced prints with harsh feel. There-fore, partial substitution of kerosene emulsion (60-80%) was tried and a significant improvement inthe handle of fabric was observed.

Keywords: Bending length, Colour value, Kerosene emulsion, Pigment printing, Synthetic thickener

1 IntroductionPigment prints on cotton using kerosene emul-

sion thickener are characterized by good fastnessproperties and high degree of brilliance with noadverse effect on the handle of the fabric. How-ever, there is an increasing tendency towards thesubstitution of kerosene emulsion by syntheticthickeners due to disadvantages like risk of explo-sion in the drier, air pollution, loss of valuablekerosene during drying and curing processes, andinadequate availability of kerosene for domesticuse":'.

Successful use of aqueous system for pigmentprinting and its beneficial effect on safety, envi-ronmental pollution and economy of operationhas given added impetus to the use of syntheticthickenersv". Synthetic thickeners are high molec-ular weight polymers (M, 3,00,000-5,00,000)containing an acidic monomer such as. acrylic,methacrylic or maleic acid as an essential compo-nent. Acid comonomer appears to be the majorconstituent of such synthetic thickeners as it is re-sponsible for the building up of viscosity on neu-tralization with a base which is necessary forthickening action. Neutralization converts the acidgroups into carboxylate anions which repel eachother, resulting into uncoiling of the polymerchains, thereby developing the viscosity.

"To whom all the correspondence should be addressed.

Copolymers of acrylic or methacrylic acid withtheir esters":" or acrylamide':', and ethylene andmaleic anhydride!", and their crosslinked polym-ers using ethylene glycol dimethacrylate, N,N'-methylene bisacrylamide, divinyl benzene, methy-101 acrylamide, etc. as crosslinking agents havebeen primarily used as thickeners for textile print-ing. Different systems for replacing kerosene, par-tially or completely, based on these chemicalcompositions have been evaluated. Informationregarding the chemical compositions and synthe-sis of such thickeners, available in patented litera-ture, has been documented recently".

In the present paper, the performance of me-thacrylic acid-based synthetic thickeners, as sub-stitutes of kerosene emulsion thickener, in pig-ment printing of cotton fabric is reported. Fourorganic pigments were used. Performance wasevaluated on comparison with the prints obtainedfrom a commercial synthetic thickener (AlcoprintPTF) and conventional kerosene emulsion thick-ener.

2 Materials and Methods

2.1 Polymer PreparationEmulsion polymerization of methacrylic acid-

ethyl acrylate-ethylene glycol dimethacrylatelN,N'-methylene bisacrylamide was carried out at50°C using potassium persulphate (0.125 wt % of

CHAVAN et al: PIGMENT PRINTING OF COTTON 23

monomers)-sodium metabisulphite (0.25 wt % ofmonomers) as redox initiator and a mixed emulsi-fier containing non-ionic and ionic emulsifyingagents. Methacrylic acid-ethyl acrylate ratio waskept at 65:35 and the amount of crosslinking agentswas varied to get the desired viscosity for printing.

Details of synthesis and rheological behaviourof methacrylic acid-based synthetic thickeners hasbeen reported elsewhere",

2.2 Fabric

Cotton fabric used for printing was scoured andbleached. It had the following specifications: warpcount, 62; weft count, 74; and weight,96g1io2•

2.3 Printing Auxiliaries

Acramine Binder SLN of Colour Chern Ltd (In-dia), Pidifix 361-a melamine-formaldehydebased fixer of Pidilite Ind (India), Golden YellowTRM, Black TBR, Blue TFB pigments of Good-lass Nerolac Paints Ltd (India), and AcramineRed FGR of Colour Chern Ltd (India) were usedfor printing. Carboxymethyl cellulose (completelywater soluble) of Loba Chemie Indoaustranal Co.(India) and urea of BDH Chemicals (India) wereused for the preparation of kerosene emulsion.Diammonium hydrogen phosphate (DAP) ofMerck Ltd (Germany) was used as a catalyst.

2.4 Print Paste and Stock Paste Formulations

2.4.1 Stock Paste

2.4.1.1 Kerosene Emulsion Thickener

Ingredient

Acramine Binder SLNUreaCarboxymethyl Cellulose (6%)WaterKerosene

Parts

1021

1077

2.4.1.2 Synthetic Thickener Paste

The polymer content of the emulsion of me-thacrylic acid-based terpolymers varied between16 and 18%. To prepare the stock paste fromthese emulsions, desired amount of water wasadded to the emulsion so as to bring down thepolymer content to 4%, and then 28% ammoniumhydroxide solution was added to adjust the pH to

7.5. In case of Alcoprint PTF, 2% solution wasprepared and the pH was adjusted to 7.5.

2.4.2 Printing Paste

Ingredient Kerosene emulsion Synthetic thickener(Parts) (Parts)

Other Black Other Blackcolours colour colour colour

4 6 4 62 2 2 2

PigmentPidifix 363(fixer)DAP(catalyst)Acramine SLN(binder)Stock paste

1.5 1.5

5 10 15

92.5 85.5 84 77

100 100 100 100

With Alcoprint thickener, the viscosity of the ~printing paste increased significantly on additionof black pigment, which was brought back to nor-mal by the addition of 2 parts ammonium sulph-ate as suggested by the manufacturer.

2.5 Printing

Samples were screen printed with two squeegeestrokes followed by drying of the printed samplesat 90°C for 4 min and curing at 150°C for 5 min.In the case of methacrylic acid-based thickeners,fixation was carried out at 170°C for 5 min.

2.5.1 Partial Substitution of Kerosene Emulsion

Blends 'of synthetic thickeners (laboratory syn-thesized products and Alcoprint) and keroseneemulsion were prepared in the ratio of 80:20 and60:40 (w/w) and used for printing.

2.6 Evaluation of Printed Samples

The prints obtained were evaluated in terms ofcolour value, wash, rob and scrub fastness, andstiffness.

Colour value from front and back to determinethe back penetration -was expressed in terms of KIS and was determined by using ACS Spectro-Sen-sor II (Applied Color Systems Inc. Spectro-photometer). The wash fastness (ISO 3) was de-termined using Atlas launderometer and dry andwet rub fastness was determined using Shirleycrockmeter. Scrub fastness was measured by

24 INDIAN J. FIBRE TEXT. RES., MARCH 1994

scrubbing the sample, dipped in soap solution,100 times with a nylon brush. Stiffness of thesamples was measured in terms of bending lengthby using Eureka bending length tester.

2.7 Viscosity MeasurementThe viscosity of the various pastes was mea-

sured using Brookfield Viscometer (Model RV,Spindle No. 29).

3 Results and DiscussionThe composition of various synthetic thickeners

investigated in the present study are given inTable 1. Also included in this table is the code ofeach, which will be used hereafter.

3.1 Viscosity of Stock and Print PastesBrookfield viscosity of all the stock pastes and

printing pastes were measured (at 5 rpm) and thevalues are reported in Table 2. Stock pastes of allthe three methacrylic acid-based thickeners wereprepared at a concentration of 4% for achievingprintable viscosity. Among the three syntheticthickeners, P2M3, P2E4 and P2Es, Brookfield vis-cosity of P2M3 was the highest (70,400 cp). Theviscosity of PZE4 and P2Es was 32,000 and26,000 cp respectively. This behaviour can be ex-plained on the basis of the gel content of thesepolymers, which gives an idea of the degree ofcrosslinking. According to Kanter", crosslinkedpolymers do not undergo dissolution on the addi-tion of bases but they swell. Therefore, higher thedegree of crosslinking, higher will be the viscosity.P2M3, showing the highest viscosity value, had agel content of 90.7% as compared to 83.0 and80.6% for P2E4 and P2Es respectively. Keroseneemulsion had a viscosity of 63,000 cp and Alco-print PTF (2% solution) had a Brookfield viscos-ity of 1,11,000 cpo When the printing auxiliarieslike binder, pigment and fixer (and catalyst in thecase of kerosene emulsion only) were added tothe stock paste, a drop in the viscosity in all thecases was observed, maximum drop being in thecase of Alcoprint PTF. The drop in viscosity wasmore prominent in cases where the initial viscos-ity was higher. The extent of reduction in viscos-ity varied with different pigments. With black pig-ment, v.iscosity was lowest because 5% extra bin-der and 2% extra pigment were added to thispaste.

3.2 Printing Performance of Synthetic Thickeners

3.2.1 Colour Value (KIS)The K /S values from the front and back side

Table I-Chemical composition and code of variousthickeners used for pigment printing

Feed concentration Polymer Monomer Codecontent conversionused for efficiencyprinting %

%

MAA:EA(65:35)EDGM «3%)

MAA:f:A(65:35)EGDM (>3%)

MAAEA(65:35)MBAM-(H%)

AJcoprint PTF (Acrylic-based commercial thickener)Kerosene emulsion

80:20IP2E4:KE60:40IP2E4:KE80:20/P2E5:KE60:40/PzE5:KE80:20IP2M3:KE60:40/P2M3:KE80:201AL:KE60:401AL:KE

4 89

4 88.5 P2E5

4 90 P2M3

2" AL

KE3.2 P2E4K22.4 P2E.K.3.2 P2E5K22.4 P2E5K4

3.2 P2M3K2

2.4 P2M3K.1.6- ALK21.2" ALK.

MAA-Methacrylic acid; EA-Ethyl acrylate; EGDM-Ethy-lene glycol dimethacrylate; and MBAM-N,N'-methylene bis-acrylamide .-Commercial emulsion concentration

Table 2-Brookfield viscosity of stock paste and print paste(at 5 rpm, spindle no. 29)

Sample Stock Print paste viscosity, cpcode paste

viscosity Red Blue Golden Blackcp FGR TFB yellow TBR

TRM

KE 63,000 37,400 16,400 10,000 7000P2E4 32,000 \7,000 14,000 16,800 11,200P2E.K2 33,600 30,400 14,400 15,000 12,800P1E.K4 31,400 28,400 13,800 16,600 11,600P1Es 26,000 20,400 12,000 11,600 7800P1EsK2 43,600 16,800 7400 9000 7600P2E5K4 35,600 17,800 8000 8600 7200P1M3 70,400 13,400 10,000 9200 5600.P2M3K2 53,800 12,000 8200 7000 5000P2M]K4 39,400 9800 6200 5200 5000AL 1,11,400 17,800 19,400 23,400 12,000ALK2 96,600 22,000 18,200 17,200 7000ALK4 66,200 22,800 15,800 14,600 6200

CHAVAN et al: PIGMENT PRINTING OF corros

(back penetration) of the cotton printed with dif-ferent thickeners are shown in Fig. 1. It is ob-served that the K IS values of all the samplesprinted with synthetic thickeners, including thecommercial Alcoprint PTF, were lower than thoseprinted with kerosene emulsion. Similar observa-tion was made with all the four pigments, i.e. red,blue, yellow and black.

All the three laboratory synthesized thickeners(P2E4' P2ES and P2M3) showed better performancethan Alcoprint in terms of KIS values in the caseof red and blue pigment, whereas in yellow pig-ment, the KIS value was very low and in case ofblack pigment, a little difference was observed.

Among the three lab synthesized thickeners,P2Es showed better performance with red andblack pigments and P2E4 with blue pigment. Nosignificant difference was observed in the case ofyellow pigment.

The samples printed using synthetic thickeners,including Alcoprint, showed higher back penetra-tion than those printed using kerosene emulsion.Higher back penetration may be attributed toaqueous based synthetic thickeners due to whichmore of print paste is absorbed by the cotton fa-bric. However, kerosene emulsion being oil basedthickener can not penetrate much in the fabric ..

3.2.2 Fastness PropertiesWash and rub (dry and wet} fastness properties

of the prints obtained from laboratory synthesizedthickeners were comparable to those obtainedfrom kerosene emulsion and Alcoprint PTF.However, scrub fastness of these samples was in-ferior to that of the samples printed with kero-sene emulsion and Alcoprint PTF, which may bean outcome of incomplete fixation. The fixationwas carried out at 150°C for 5 min for all thesamples.

It is believed that during fixation the functionalgroups of binder like N-methylol acrylamide react

~I

0

"'o Front sid'! r:. Boc k SIM '" "''" ~5

"' :;:~~;"' .. "' ~ '"'" "' ~" .. ~ ~ ~~;. "- s:

~ o.~ 0. cr' "' "' ~ ..cr' ~ "0. ~

~

:; Q. 0. Q. ~

(

0 i

5

~ ~ ~ ~ao r,j fA ~ f.J

ACRAMINER~dFGR

B toe T F B Gold ••" V •. llow Block TBRTRM

Fig. 1- K IS values of cotton printed with different thickeners

25

with the hydroxyl groups of cotton and form afilm on the surface of the fabric. Acidic pH is re-quired for this reaction to occur".Binder - CH20H +HO - Cellulose

l pH3

Binder - CH2 - 0 - Cellulose +H20In case of kerosene emulsion, diammonium hy-

drogen phosphate (1.5%) was added, which creat-ed the requisite pH of 3 by in situ generation ofphosphoric acid and ammonia at a temperature of150°C as shown below:

150°C(~h HP04 ' H3P04 + 2NH3 tIn case of synthetic thickeners, no external ca-

talyst was added because it is assumed that theammonium carboxylate groups formed during thepreparation of paste (neutralization of acidgroups) liberate the ammonia which is evaporatedand acid groups are regenerated giving the acidicpH as shown below:

CH3

I-CH2-C -

ICOONHt

CH3

~""""CH2-b ---+NH3 tICOOH

The poor scrub fastness of the samples ob-tained from methacrylic acid-based thickeners ispresumably due to the inadequate dissociation ofthe carboxylate groups as a result of which thedesired pH is not achieved at 150°C. Therefore,curing of these samples was carried out at 170°Cfor 5 min to ensure complete dissociation of am-monium carboxylate ions as well as evaporationof ammonia. The samples obtained were testedfor their fastness properties (Table 3) and com-pared with the samples printed with keroseneemulsion and Alcoprint PTF which were cured at150°C for 5 min. Dry and wet rub fastness pro-perties (in terms of staining of the white fabric) ofthe samples printed with methacrylic acid-basedthickeners were comparable to those of the sam-ples printed with kerosene emulsion and Alco-print PTF using all the four pigments. Wash andrub (dry and wet) fastness (in terms of change ofcolour) was invariably 5 in all the cases. Scrubfastness was comparable to that of the Alcoprintand kerosene emulsion printed samples in case ofyellow and black pigments, whereas in case of redand blue pigments, it was lesser but within the ac-ceptable limits.

Performance of P2E4, P2Es and P2M3 was com-

26 INDIAN 1. FIBRE TEXT. RES., MARCH 1994

Table 3- Fastness properties of the prints obtained using different thickeners

Sample Red FGR BlueTFB Golden Yellow TRM BlackTBRcode

Dry rub Wet rub Scrub Dry rub Wet rub Scrub Dry rub Wet rub Scrub Dry rub Wet rub Scrub

KE 4 4 5 4 4-5 5 4-5 4-5 5 4 4 3-4AL I 4 5 4-5 4-5 5 4-5 4-5 5 4 4 4pzc. 4 4 2-6 4-5 4-5 3-4 4-5 4-5 5 4 4 3-4PzE, 4-5 4 3 4 4-5 3-4 4-5 4-5 5 4 4 2-3PZM.1 4 4 2-3 4 4-5 2-3 4-5 4-5 5 4-5 4-5 4

Dry and wet rub fastness reported in this table are rated for the staining of the white fabric.

parable in terms of wash and rub fastness in allthe four pigments. However, in case of P2M3'scrub fastness was inferior in the samples printedwith blue pigment, whereas it was higher than thatof kerosene emulsion printed samples in case ofblack pigment.

3.2.3 Bending LengthThe samples printed with kerosene emulsion

using red, blue and yellow pigments had bendinglength in the range of 1.60-1.67 em as comparedto 2.5-2.58 cm in case of Alcoprint and 2.87-3.43em in case of P2E4, P2Es and P2M3 (Table 4).With black pigment, the kerosene emulsion print-ed samples had a bending length of 1.92 em ascompared to 3.6-3.8 cm in the samples printedwith methacrylic acid-based synthetic thickeners.Higher bending length of the samples printed withsynthetic thickeners is due to the thickener resi-due left on the surface of printed fabric alongwiththe binder.

Of the three methacrylic acid-based thickeners,P2ES gave the best prints in terms of feel of thefabric. This behaviour may be correlated with theI;, and crosslink density (gel content) of the po-lymers employed as thickeners for printing. High-er the crosslink density, greater wiu be the bend"ing length of the prints. However, this is not truefor all the pigments used in the present study.

Conventionally, no after wash treatment isgiven in the pigment printing before testing thestiffness of the printed samples. However, in thepresent study, the samples printed with P2E4,

P2Es and P2M3 using blue pigment were washedand the bending length of the washed sampleswas measured. Before washing, the bending lengthof the samples printed with P2E4, P2Es and P2M3

was 3.38, 2.87 and 3.06 em respectively and itdecreased to 2.6, 2.1 and 2.1 cm respectively af-ter washing. A maximum reduction of 29.2% wasobserved in case of P2M3 which had the maximumgel content (90.7%). This confirms the effect of

Table 4-Bending length of cotton printed with differentthickeners

Sample Bending length, cmcode

Red Blue Golden BlackFGR TFB Yellow TBR

TRM

KE 1.65 1.67 1.60 1.92AL 2.58 2.51 2.50 3.80P2E• 3.27 3.28 3.30 3.70P2Es 3.17 2.87 3.26 3.60P2MJ 3.37 3.06 3.43 3.60

Bending length of control fabric, 1.45 em

crosslink density of the thickener on the feel ofthe fabric. Higher bending length of washed print-ed samples in comparison to that of the unprintedsample may be correlated with the thickener-bin-der interaction film.

In order to improve the feel of the fabric, it wasdecided to use the synthetic thickeners in combi-nation with the kerosene emulsion thickener andcheck the suitability of the laboratory synthesizedproducts for partial replacement of kerosene.

3.3 Partial Substitution or Kerosene Em.ulsionBlends of the synthetic thickeners (laboratory

synthesized and Alcoprint) with the keroseneemulsion thickener were prepared in two differentratios, viz. 80:20 and 60:40 (w/w). The code andviscosities of these products are given in Tables 1and 2 respectively.

The samples printed with these mixtures, usingfour pigments, were tested for colour value, fast-ness and bending length.

3.3.1 Colour ValueOn using the mixture of synthetic and kerosene

emulsion thickeners, prints obtained with all thepigments were much brighter, sharper and more

CHAVAN et al.: PIGMENT PRINTING OF COTTON 27

uniform than those obtained with 100% syntheticthickeners (including Alcoprint) or 100% kero-sene emulsion thickener.

In case of Alcoprint PTF, the K IS value im-proved on using the mixture of Alcoprint andkerosene emulsion with all the four pigments(Figs 2-5). The colour values of ALK2 and ALK4printed samples were comparable to those of KEprinted samples in case of red pigment, lower inyellow and blue pigments, and better in black pig-ment.

In case of laboratory synthesized thickeners, theblends of synthetic and kerosene emulsion thick-eners (80:20 and 60:40) gave better K IS values ascompared to the 100% synthetic thickener withred and black pigments. No significant improve-ment was observed with yellow and blue pig-ments.

As far as comparison with kerosene is con-cerned, the laboratory synthesized products gavecomparable colour values when used for partialsubstitution of kerosene (60-80%) in case of redand black pigments, whereas in yellow and bluepigments the values were lower but quite compar-able to those obtained with commercial thickeners.Alcoprint PTF {AL), Al.K2 and ALK4 (Figs 2-5),showing the commercial viability of the productsinvestigated in the present study for partial substi-tution of kerosene. The observed improvement inK IS value on using the mixture of synthetic andkerosene emulsion thickeners is due to the eva-poration of kerosene as a result of which the re-sidual thickener left on the printed fabric is 20-40% less as compared to that on the samplesprinted with 100% synthetic thickener. However,the samples printed with P2E4K2, P2ESK2 andP2M3K2 showed higher colour values than thesamples printed with PZE4K4, P2EsK4 and P2M3K4using red and black pigments. This is not in ac-cordance with the diluent effect of kerosene onthe thickener residue, mentioned above. Thisanomalous behaviour may presumably be relatedto the agglomeration of pigments vis-a-vis poordispersion in the mixture of synthetic and kero-sene emulsion, particularly in red and black pig-ments when higher amount of kerosene emulsion(40%) was incorporated. Out of three methacrylicacid-based thickeners, performance of P2ES wasbetter than the other two, with red and black pig-ments, for 80% as well as 60% kerosene substitu-tion, while for the blue pigment, P2E4 thickenergave higher KIS value. A similar trend was ob-served when these polymers were used for 100%substitution of kerosene. In case of yellow pig-ment, almost similar K IS values were obtained

30.-------------------------------------~o Front~. m 8ack sid.-

...'"

" .•.• "... .••• N •••

.~ Q. C..~..'"~15

o

Fig. 2- KIS values of colton printed with mixtures of synthe-tic and kerosene emulsion thickeners using Acramine red

FGR pigment

'":;,

0 Front sic:k> 0 80ck .itt.

... .. .•" .• N" '".. '" .• ..

N c"-

~ w'>l W '" N '" " "-N ~ .."- '" ~ r ,{''" .. Q. a.N C s: '" .. .t'~ ~ ~,..rr A.N.. ..

5

0

5 ~i0 ~ 11 ~ ~ D ~

30

20

Fig. 3-KIS values of cotton printed with mixtures of synthe-tic and kerosene emulsion thickeners using Blue TFB pigment

30... o Front S!df. • BOck ~I';'"5 .•

-e " N .• .•N •• ;' "'" "

~-.I' "';.." "0

~ ~ ~ '" '" '" " ," i'.• -c « .. ••• A. ... ... ... :>...Q.N ci :>: .r-s: 0::- .. .r-..

5

~ ~ ~ ~ ~ ~ ~ ~ r.J

10

Fig. 4-KIS values of cotton printed with mixtures of synthe-tic and kerosene emulsion thickeners using Golden yellow

TRM pigment

'"<,

" 1

o Front SIck IIBack side-0 e .•

;t " "N;'~w ..• N· s:5 " " ...'".•

,," ~ rr :c: .r- .•~ •• w ".. ~ ~ ..... a.N ... :>:" f'0

.. e: ..N ..N••N

5

0

5

~ ~ ~ ~ ~~ ~ ~ ~~ig. 5- KIS values of colton printed with mixtures of synthe-nc and kerosene emulsion thickeners using Black TBR

pigment

28 INDIAN J. FIBRE TEXT. RES., MARCH 1994

Table 5 - Fastness properties of the prints obtained using mixtures of synthetic thickeners and kerosene emulsion

Sample Red FGR B1ueTFB Golden Yellow TRM B1ackTBRcode -----

Dry rub Wet rub Scrub Dry rub Wet rub Scrub Dry rub Wet rub Scrub Dry rub Wet rub Scrub

KE 4 4 5 4 4 5 4-5 4-5 5 4 4 3-4

ALK2 4 4 5 4 4 4 4-5 4-5 5 4 4 4

ALK. 4 4 5 4 4 4 4-5 4-5 5 4 4 4

P2E•K2 4 3-4 3 4 4 2-3 4-5 4 3-4 4 4 3

P2E.K. 3-4 3 3 4 4 3-4 4-5 4 5 3-4 4 3-4

P2E,K2 4 4 3-4 3-4 4 3 4-5 4 5 4 4 3P2E;K. 3 3-4 4 3-4 4 3-4 4 4 5 3-4 4 2-3P2M.lK2 4 3-4 2-3 4 4-5 2-3 4 4 5 4 4 4P2M.lK. 3-% 3-4 2-3 4 4 2-3 4 4 5 3-4 3-4 4

Dry and wet rub fastness values reported in this table are rated in terms of the staining of the wuite fabric.

with all the three thickeners. Performance of P2M3was comparable to that of P2Es with red pigmentand to that of P2E4with blue pigment.

Irrespective of the pigment, back penetrationwas higher in all the samples printed with -themixtures of kerosene emulsion and syntheticthickener as compared to that in the samplesprinted with 100% kerosene emulsion or 100%synthetic thickener. The back penetration in caseof ALK2, P2E4K2, P2EsK2 and P2M3K2 was high-er than that in case of ALK4, P2E4K4, P2EsK4

and P2M3K4.

3.3.2 Fastness Properties. The fastness properties, except the scrub fast-ness, of the samples printed with the blends ofP2E41P2EslP2M3 and kerosene emulsion werecomparable to that of Alcoprint and keroseneemulsion printed samples (Table 5). Wash fastnesswas invariably 5 in all the cases. Dry and wet rubfastness (in terms of change of shade) was also 5.The scrub fastness was comparable to standardswith black and yellow pigments and slightly inferi-or with red and blue pigments.

All the three laboratory synthesized thickenersgave comparable wash and rub (dry and wet) fast-ness with all the four pigments. Scrub fastness wasless (2-3) in case of P2M3K2 and P2M3K4 withred and blue pigments. With. black pigment, thescrub fastness was comparable to that of Alco-print printed samples, and was higher than that ofkerosene emulsion printed samples",

3.3.3 Bending LengthWith the incorporation of kerosene emulsion in

!he laboratory synthesized as well as commercialsynthetic thickener there was significant improve-ment in the fabric handle, as expected. The in-

Table 6-Bending length of the cotton printed with the mix-tures of synthetic thickeners and kerosene emulsion

Sample Bending length, cmcode

Red Blue Golden BlackFGR TFB Yellow TBR

TRMKE 1.65 1.67 1.6 1.92ALK2 2.11 2.05 2.25 3.23ALK4 2.03 2.07 1.97 3.08P2E4K2 2.48 2.32 2.30 2.60P2E4K4 2.12 1.97 1.93 2.26P2EsK2 2.45 2.46 2.2 2.63P2EsK. 2.13 2.08 1.88 2.18P2M)K2 2.58 2.63 2.6.1 2.70P2M¥4 2.17 1.91 1.92 2.13

Bending length of control fabric, 1.45 cm

crease in kerosene emulsion from 20% to 40%gave lower values of bending length (Table 6). Incase of P2E4K2, P2EsKz and PZM3K2 (the compo-sitions containing 20% kerosene emulsion), thebending length values were comparable to that incase of Alcoprint (AL). With the compositionscontaining 40% kerosene emulsion (P2E4K4,

PzEsK4 and P2M3K4), the bending length dec-reased further, became lower than that in case ofAlcoprint but was slightly higher than that incase of kerosene emulsion. The samples printedwith P2E4K/P2E4K4 and P2ESK21P2ESK4 hadcomparable bending lengths while the samplesprinted with P2M3K/P2M3K4 were little harsherwith all the pigments.

4 ConclusionsThe laboratory synthesized thickeners when

used for pigment printing of cotton gave good re-sults in terms of colour -value, print sharpness, un-

CHAVAN et al.: PIGMENT PRINTING OF COTTON 29

iformity, and wash and rub fasUtess. Scrub fast-ness was lower than that of kerosene emulsionprinted samples with red and black pigments.Bending length was as high as 2.83-3.43 em ascompared to 1.60-1.67 em in case of keroseneemulsion printed samples. Handle of the fabricwas significantly improved by using 80:20 and60:40 (w/w) blends of synthetic and keroseneemulsion thickeners. Hence, the laboratory syn-thesized thickeners can be successfully used for60-80% substitution of kerosene in pigment print-ing. Out of the three thickeners synthesized, P2E5

gave the best performance in terms of bendinglength, colour value and fastness properties.

AcknowledgementOne of the authors (M G) wishes to thank the

University Grants Commission, India, for provid-ing the financial support in the form of researchfellowship.

References1 Davids J H, Colourage Annual; 21 (1974) 60.2 Schwindt W, Faulhaber G & Moore, Rev Prog Colour, 2

(1971) 33.

3 Ratcliffe W A, Rev Prog Color, 7 (1976) 43.4 Seddon R, Arn Dyestuff Rep. 74 (Feb. 1985) 13.5 Clarke W & Miles L W C, Rev Prog Color, 13 (1983) 27.6 Humpheries A, Muff J R & Seddon R, Colourage, 32

(March 1985) 15.7 Bajaj P, Chavan R B & Manjeet B, Rev Macrornol Chern

Phys, C24 (3) (1984) 387.8 Shenai V A & SarafN M, Colourage, 28 (Oct. 1981) 44.9 Norimasa H & Yuzuru Y, Eur Pat 19660 (to Dianippon

Ink and Chern Inc.), 1980; Chern Abstr, 94 (1981)158251q.

10 Gajdo S, Emeric, Russescu & Dumitru, Romanian PatRO 96973 (to Inter Prinderea Chimica, Risnov), 1989;Chern Abstr, 114 (1991 ) 83813p.

11 Drahomir D, Karel C & Peter C, Czech Pat CS 2585371989; Chern Abstr, 112 (1990) 79362k.

12 Langerbins K, Hans T, Josef K & Wolfgang K, Eur Pat398151 (to Roehm GmbH), 1990; Chern Abstr, 114(1991) 83552c.

13 Flesher P, Farrar D & Allen A, Eur Pat 343840 (to Alli-ed Colloids Ltd), 1989; Chern Abstr, 112 (1990) 180577f.

14 Nikolaeva T I, Senakhov A V & Repina E V, Izv VuzovTekhnol Tekst Promsti; 6 (1983) 71; Chern Abstr, 100(1984) 69737w.

15 Bajaj P, Meenakshi Goyal & Chavan R B, Rev MacrornolChern Phys, C33'(3) (1993) 321.

16 Bajaj P, Meenakshi Goyal & Chavan R B. Polym Gel Network(communicate?).

17 KanterG, A", DyestujfRep, 65 (1976) 52.18 Miles L W C, Textile printing (The Dyers Company Pu-

blications Trust), 1981, 141.