e2010.10 2011.pdf3114. in addition, choosing the right linker can alter hapo’s hydrolysis...

E2010.10.19

Anti-oxidantsGeneral introduction

Primary anti-oxidantsHindered phenolic anti-oxidantsMetal deactivatorsBenzofuranone anti-oxidantsHydroxylamine anti-oxidants

Secondary anti-oxidantsPhosphorous based anti-oxidantsSulfur based anti-oxidants

UV stabilizersIntroduction of photo-oxidation pathway

Flame retardantsGeneral introduction

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1

379

13

1517

232733374147

515355

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Table of contents

Benzotriazole based Benzophenone basedTriazine basedOthers & formulatedHindered amine light stabilizers

Non-halogen basedHalogen based

OthersPVC heat co-stabilizers --------------------------------------------------------

Available packagingsPhysical appearances

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5758

21

As shown in Scheme 1, there are 5 types of active ingredients which are able to trigger the polymer degradation in the thermal oxidation pathway. They are: 1) carbon-centered radicals; 2) peroxy radicals; 3) hydroxyperoxides; 4) oxy radicals; 5) hydroxy radicals. Substances that are able to deactivate these 5 matters can greatly reduce oxidative damage which are defined as anti-oxidants (AOs).


1

Scheme 1. Thermal oxidation pathway. Carbon-centered radical shown in blue was initially generated by heat via hydrogen abstraction (there are other ways of generation). This radical went either to bond scission pathway or reacted with oxygen to form peroxy radical followed by hydrogen abstraction again to generate a hydroperoxide and a carbon-centered radical. Hydroperoxide was fragmented into a hydroxy radical and an oxy radical which caused further degradation by hydrogen abstraction and bond scission.

Introduction

Main target

for secondary anti-oxidants

Main targets for primary anti-oxidants

thermolysis

O2

OO

peroxy radical

further degradation

hydrogenabstractionO

OHO

hydroperoxide

Heat

HO +

oxy radicalhydroxy radical

H

hydrogenabstraction

hydrogenabstraction

Heat

Heat

Heat


2

Introduction

Among various AOs, those of which that are able to quench the radicals are called Primary AO. This type of AO can effectively prevent the loss of mechanical properties, e.g. melt-flow index. Another large class of AOs that scavenges hydroxy peroxide is called Secondary AOs, with a prominent functionality to curb discoloration.

Primary AO can be further divided into several subcategories. The biggest sub-category is called hindered phenolic AO. It is also the most popular AO because of its high performance/cost ratio. Apart from the phenolic AO family, several new primary AOs had been commercialized recently, e.g. hydroxylamine, benzofuranone, and phenolic acrylate. These alternate AOs were introduced in the market to respond particular requirements such as non-phenol and anti-gasing.

In general, secondary AOs can be categorized into 3 sub-families, i.e. phosphorous based, sulfur based, and amine based. Phosphorous based AO is mainly used for olefin type polymers, while the latter two are commonly used for rubber-like polymers.

When primary AOs and secondary AOs are used together, a synergistic effect will occur. This effect not only enhances the AO performance, but also reduces the overall cost. As a common practice, primary AOs and secondary AOs are used in combination in almost all the AO formulas.

Beside the synergistic effect, the following factors should be taken into consideration when looking for an optimal AO system.

1. polymer type 4. cooling systems2. process temperature 5. compatibility3. heat stability 6. physical and mechanical requirement

Our AO laboratory, equipped with the state-of-the-art instruments, is happy to run AO screening for our customers. Please contact Chitec distributors.

Anti-oxidantsHindered phenolic anti-oxidants (HPAO)

The hindered phenolic name is derived from a unique structure of this type of AO: hydroxyl moiety on the phenol is flanked by two bulky groups (R1 & R2). This special structure allows HPAO to release hydrogen to quench peroxy radicals at high temperatures without jeopardizing the phenol from being oxidized to a quinone, which is a chromophore. HAPO oxy radical produced after hydrogen releasing on Scheme 2 is stabilized by various resonance forms and is able to quench another peroxy radical, making it a two-radicals scavenger.

As the bulkiness of R1 & R2 increases, the working temperature for HAPO also rises, and its AO ability also augments. Therefore, for low process temperature (<150 ˚C) polymers such as rubber, less bulkier HPAO (e.g. Deox 112) usually delivers better performance. On the contrary, high process temperature (>200 ˚C) polymers will gain better AO result by adding bulkier HPAO such as Deox 10. The bulkiness of R1 & R2 also affects the life of AOs as their ability to protect the hyroxyl group. AO with a bulkier R1 & R2 has longer life and is usually called long-term AO. It is most suitable for applications involving with recycle. Opposed to long-term AO, AO with low bulkiness R1 & R2 is called short-term AO, which is commonly used for thermoset applications where recycle is not required.

To increase heat stability, several HAPOs can be bound together with linkers, e.g. Deox

3114. In addition, choosing the right linker can alter HAPO’s hydrolysis resistance (Deox

1330), UV stability (Deox 1790), and even its physical state (Deox BS-1000 as liquid).

AO, when equipped with a metal-chelating group, is called metal deactivator, which can substantially increase the life of polymers in contact with metal (e.g. wire and cable).

Primary anti-oxidants

3



Scheme 2. General structure of hindered phenolic anti-oxidant. Hydroxyl group at the 1st position are flanked by two alkyl groups, R1 and R2. The hydroxyl group is able to release a hydrogen (shown in red) to quench the peroxy radical generated by thermal oxidation. The rate of hydrogen-releasing is determined largely by the bulkiness of R1& R2 and temperature. The bulkier the group, the slower the rate. On the contrary, the higher the temperature, the faster the speed. The commonly seen R1 & R2 are methyl, methylene, and tert-butyl groups, whereas the other three substituents, R3, R4, and R5, are used as linkers to other substituents.

4

OH

R1R2

R5

R3

R4

O

R1R2

R5

R3

R4

O

R1R2

R5

R3

R4

O

R1R2

R5

R3

R4

OR1

R2

R5

R3

R4

OO R

OO

O2

oxy radical



Deox 10 Deox 112

5

Deox 115 Deox 1330

REACH Status: items listed above are all pre-registered, except for Deox BS-1000 which will be registered later on.

NameDeox 10Deox 112Deox 115Deox 1330Deox 1790Deox 3114Deox BS-1000

CAS No.6683-19-8119-47-133145-10-71709-70-240601-76-127676-62-6144429-84-5

AppearanceWhite powderWhite powderWhite powderWhite powderWhite powderWhite powderSlightly yellow liquid

Melting point110-125 ˚C128 ˚C min.160-164 ˚C240-245 ˚C159-163 ˚C218-223 ˚C-

UniquenessLow costLight color rubberLow working temperature (<100 ˚C)Hydrolysis resistantHigh TGA/Anti-gas-fadingUV stabilityLiquid

Deox 1790 Deox 3114



Deox BS-1000

O O

OH

Metal ions catalyze the decompositon of hydroxy peroxides, forming reactive radicals as shown below:

Metal deactivators form stable complexes with metal and its ion as shown below. As a result, the process deactivates the metal catalyzed destructions.

Metal deactivators resemble each other with minor difference in the length of diamine linkers (blue region), which affect their compatibilities in polymers and their effectiveness as metal chelators.

7Prim

ary anti-oxidants

Scheme 3. Metal deactivator chelates with Cu ion.

Anti-oxidantsHindered phenolic anti-oxidants (HPAO)Metal deactivators

Deox MD-1024

8



Metal deactivators

Deox MD-1098

Deox MD-1072

REACH Status: items listed above are all pre-registered.

NameDeox MD-1024Deox MD-1072Deox

MD-1098

CAS No.32687-78-869851-61-223128-74-7

AppearanceWhite powderWhite powderWhite powder

Melting point221-232 ˚C170 ˚C min.156-161 ˚C

ApplicationsPE, PPEngineering plasticsNylon

Benzofuranone AOs were discovered in the early 80’s. They are known for their superb ability to quench carbon-centered radicals as shown in scheme 4. Carbon-centered radicals, as illustrated on page 1, appeared at the very beginning of the thermal oxidation pathway. Their decomposition ensures a very efficient way of inhibition on degradation. In fact, when used in combination with phosphorus AOs, there was an unprecedented synergistic AO effect that was observed on the melt flow index and color stability.

Scheme 4. Radicals scavenged by benzofuranone based anti-oxidant.

Anti-oxidantsPrimary anti-oxidantsBenzofuranone based anti-oxidants

9Prim

ary anti-oxidants

OH

R1R2

R3

R1R2

R3

R1R2

R3

O

O O

O

OHheat

or

or

R1R2

R3

O

O

R1R2

R3

O

O OO

R1R2

R3

O

O R

Note 1: Detailed mechanism proposed by J.C. Scaiano. Please refer to JACS, 2006, 128, 16432-16433 and reference listed therein.

Anti-oxidantsPrimary anti-oxidants

Benzofuranone based anti-oxidants

10


REACH Status: items listed above will be registered.

Benzofuranone’s super AO activity has been demonstrated in numerous papers1. Unfortunately, the only benzofuranone AO commercially available was withdrawn from the market due to suspected toxicty. Chitec had recently introduced two novel benzofuranone AOs (Deox SP-3000 & SP-7000), aiming at synthetic rubbers and olfine markets respectively. Deox SP-7000, as demonstrated in figure 1.1 and 1.2, significantly enhances PP's heat and color stabilites.

Figure 1.1. Melt flow indexes (MFI) obtained from polypropylene where AOs were processed by five extrusions at 220 °C. Melt flow indexes were measured by g/10 min (190 °C, 2.16 kg). All samples contain 0.2% calcium stearate. Irganox is a trade name of Ciba/BASF. B210 is a 1:3 mixture of 1010 and 168. AOs were added as percentage by weight.

1 3 5

Control

NameDeox SP-3000Deox SP-7000

CAS No.ProprietaryProprietary

AppearanceWhite powderWhite powder

ApplicationsABS, SEBS, HIPSPP, PE, PU

Melting point114-160 ˚C105 ˚C min

Anti-oxidantsPrimary anti-oxidantsBenzofuranone based anti-oxidants


11

Figure 1.2. Yellowness(YI) (∆E) obtained from polypropylene with different AOs processed by five extrusions at 220 °C .

16

14

12

10

8

6

4

2

0

-2

-41 2 3

Control

Irganox B210 0.12%

SP-7000 0.06%

SP-7000 0.12%

1 3 5

13


Hydroxylamine based anti-oxidantsIn addition to benzofuranone, two unique amines are capable of quenching carbon-centered radicals, making them efficient primary AOs. One of them is based on hydroxyl amine, and the other one is based on hindered amine which will be introduced on page 45 .

Hydroxylamine ( ), due to its high affinity to hydroperoxide through hydrogen bonding, as shown on Scheme 5, is an active hydroperoxide decomposer. As a minor function, its oxidized intermediate ( ) can react with carbon-centered radicals. Even though hydroxyl amine is not as an efficient AO as benzofuranone, it out-performs benzofuranone in color protection for applications exposed to UV light and NO/NO2 gas-fading.

Scheme 5. Radicals scavenged by hydroxylamine.



Hydroxylamine based anti-oxidants

Deox 420

14


REACH Status: items listed above will be registered.

NameDeox 420Deox 4268

CAS No.143925-92-2143925-92-2

AppearanceOff-white powderWhite powder

ApplicationsTPO, TPE for auto parts or constructionTPO, TPE for auto parts or construction

Melting point96-98 ˚C>88 ˚C

15

Ironically, even though phosphites and phosphonites are able to decompose hydroperoxide and radicals at the same time as specified in Scheme 6, they are still customarily categorized as secondary AOs. One plausible reason for this misleading expression might lie in the superiority of their color protection than in the mechanical property protection. Nonetheless, their dual functions make them the top choice of the secondary AO.

A disadvantage of phosphites is their susceptibility to hydrolyze; they react with water to form acids, which then cause several consequent problems, such as corrosion of metal parts in the processing equipments. Therefore, all of the high-end phosphorus based AOs are resistant to hydrolysis.

Secondary anti-oxidants

Anti-oxidantsSecondary anti-oxidants

Phosphorous based anti-oxidants

ROOH

ROH

R O P O R

R O P O R

R O P O R

R

RRO

R

O

O

O

OOR

ROO

O

Further decomposeprocess

Scheme 6. Outline of the decomposition reactions on hydroperoxides and radicals by trivalent phosphorous AO. Due to high affinity of hydroxyl group to phosphorous group, hydroperoxides are decomposed quickly by phosphite AOs. Phosphrous based AO can decompose radicals, but is not as efficient as it does to hydroxyperoxides.

Deox 604 Deox 618

16



Phosphorous based anti-oxidants

Deox 3030

REACH Status: Deox 604, Deox 618, and Deox 1500 are pre-registered. Deox 3030 will be registered.

Deox BS-1500

O

O

P H P ORO

RO

OR

ORO P

R = 12-15 alkyl group

NameDeox 604Deox

618Deox

3030Deox

BS-1500

CAS No.26741-53-73806-34-635948-25-596152-48-6

AppearanceOff-white powderWhite powderWhite flakeColorless liquid

ApplicationsOlefinRubberEpoxyPlastisol

Melting point140 ˚C min37- 46 ˚C118 -121 ˚C-


Sulfur based anti-oxidants

Similar to phosphorous, sulfur based AOs are active hydroperoxide decomposers, so they are used in large quantity as secondary AOs, especially for rubber-like polymers. They do not react with radicals and thus will only improve the polymers’ color stability rather than the melt flow index. Commodity sulfur based AOs are all derived from esters of 3,3'-thiodipropionic acids, e.g. dilauryl thiodipropionate (DLTDP). DLTDP swiftly quenches hydroxyperoxides and turns into an oxidized form followed by reverse michael reactions to release sulferic acid, which is also able to reduce hydroxyperoxides as depicted in Scheme 7. Deox 1412 is also a derivative of 3,3'-thiodipropionic acids and is suitable for high temperature applications thanks to its high molecular weight structure.

Scheme 7. Hydroxyperoxide decompositions in presence of thiodipropionate esters.

17Secondary anti-oxidants

ROOHH3C

O

O S

2

H3CO

O S

2

O= + ROH

H3CO

O S

2

O=H3C

O

O S O=H

H3CO

O

+

H3CO

O S OH

O

O

( ROOH )n

SO2, SO3, H2SO3

In contrast to trivalent phosphorus based AOs, sulfur based AOs are very efficient for long-term thermal aging applications at the preferred temperature of 100-150°C. They are customarily used in combination with hindered phenolic AOs, rather than phosphorous AOs.



A new class of sulfur based AO was developed in the 90’s based on phenolic disulfide. Like hydroxyl amines, this type of AO utilizes the hydrogen bonding to increase its affinity toward hydroperoxides and hence increases their efficiency as secondary AOs as illustrated in Scheme 8.

One disadvantage of sulfur based AO is its unpleasant odor, which might cause smell issues in end applications.

OH

R1OOH

S R

RS

S R S R

S RO

OH

OOR1

S R

H

HO

+ R1OH

Scheme 8. Hydrogen bonding facilitates the decomposition of hydroperoxide by phenolic disulfide.

18


20



Deox 1412 Deox 520

Deox 726 Deox 565


REACH Status: Deox 1412 and Deox 565 are pre-registered. Deox 520 is under registeration. Deox 726 will be registered.

S C8H17

S C8H17

HO NN

NNH

C8H17

C8H17

S

S

OH

OH

C12H25

C12H25

S

S

S SOOO O

OOS SO O

NameDeox 1412Deox 520Deox 726Deox 565

CAS No.29598-76-3110553-27-0110675-26-8991-84-4

AppearanceOff-white powderColorless to light yellow liquidOff-white to wax-like solidWhite powder

Melting point44-52 ˚C-28 ˚C

91-96 ˚C

ApplicationsEngineering plasticsABS, adhesiveABS, MBS, HIDSRubber

Anti-oxidantsOthers

PVC heat co-stabilizers

21O

thers

Upon heating PVC generates HCl which catalyzes destruction of polymer chains and thus causes discoloration and loss of mechanical properties. Scavenging HCl is an efficient way to terminate this thermal degradation process. Numerous HCl acid scavengers are commercially available and they are generally called PVC heat stabilizers. Among various heat stabilizers, calcium/zinc based stabilizers are used most extensively due to its low toxicity and environmental impact.

The scavenging mechanism of calcium/zinc based stabilizers is via neutralization of HCl by calcium/zinc soap to form metal chloride salt and fatty aid. The metal chloride salt is not as efficient as HCl as a catalyst for PVC thermal degradation, but is still able to cause problems. Therefore, secondary heat stabilizers for calcium/zinc based stabilizers were developed and are generally called PVC heat co-stabilizers. They are able to deactivate further the metal chloride salt by chelating. Most commonly used co-stabilizers are diketone-based compounds such as dibenzoylmethane and stearoylbenoylmethane. The latter one is more expensive but is on FDA for indirect food contact applications.

Anti-oxidantsOthers

PVC heat co-stabilizers

22

Others

SBM-50

OOCH2 CH17H35

DBM-83

OOCH2

NameSBM-50DBM-83

CAS No.58446-52-9120-46-7

AppearanceWhite to slight yellow fine powderWhite crystalline solid

Melting point57 ˚C min.76 - 80 ˚C

ApplicationsPVCFood-contact PVC

UV stabilizersPhoto-oxidation pathway

UV stabilizers

Scheme 9. Polymers such as polypropylene demostrated above are sensitized by UV light which results in photolysis and formation of carbon-centered radicals. Like the thermal oxidation, the reactions followed by photolysis are the formation of various oxygen containing radicals and hydroperoxides. Hydroperoxide decomposition is also faciliated by UV light.

23

UV energy photolysis

UV energy hydrogenabstraction

hydroperoxide peroxy radical

hydroxy radical oxy radical

O2

+

OOO

O+

- OH

carbon-centered radicals

sensitized form

Photo-oxidation of polymers as shown in Scheme 9 involves the combined activity of UV light and oxygen. UV light provides the energy for photolysis of various bonds including carbon/carbon bonds and hydroperoxides to generate more radicals, whereas oxygen plays as an oxidant to form hydroperoxide and peroxy radicals.

In Scheme 9, the first step of the photo-oxidation is the sensitization of polymers from the ground state to the activated state by UV light, which in turn triggers the bond dissociation (also known as photolysis) to generate carbon-centered radicals followed by peroxy radicals and hydroperoxides formation superimposed on the thermal oxidation pathway.

The most visible result of photo-oxidation is the discoloration of material and at the same time the loss of mechanical properties. To retard or inhibit these kinds of deterioration has been a long-term investigation effort in the industry. Special additives called light stabilizers or UV stabilizers were developed for this purpose.

There are two main types of UV stabilizers. One is called UV absorbers, the other one is hindered amine light stabilizer (HALS). Namely, UV absorbers efficiently absorb UV light and transfer the energy into harmless heat via resonance structure interchange, and thus prevent the photolysis of polymers. The photolysis step is on the tip of the photo-oxidation stage, deactivating this step completely terminates the following cascading reactions and therefore has the best overall effect. Many UV absorbers are commercially available. In this catalog, they are grouped into four categories: benzotriazole, benzophenone, triazine, and others. Some pigments if added in large quantities such as carbon black and TiO2 can also give some UV protection, but they are farless efficient than UV stabilizers introduced in this catalogue.

UV stabilizers Photo-oxidation pathway

UV stabilizers

24

UV stabilizersPhoto-oxidation pathway

If UV light does pass on polymers and photo-oxidation does occur, HALS acts as a secondary defense system to scavenge the radicals and hydroperoxides generated. After more than 30 years of development, a variety of HALS are commercially available varying in molecular weight, basicity, physical form…etc.

The combinational use of UV absorbers and HALS are a common practice among most polymers due to their high synergistic effect, except for those polymers which are not compatible with either UV absorbers or HALS. Selection work on a suitable UV package relies on extensive tests and experiences. Chitec possesses a significant range of UV stabilizer package data base and a UV stabilizer lab equipped with many dedicated instruments which can facilitate your UV stabilizer research.

25U

V stabilizers

UV absorbersBenzotriazole based

Benzotriazole based UV absorbers are the world's largest UV absorber family counting by both dollars and tonnages. These UV absorbers have high absorption extinct coefficients as well as broad absorption spectra edges toward 400 nm, making them the first option recommended for the protection of weathering in plastics and coatings.

The elimination of the excitation energy in the form of harmless heat was thought to proceed via proton transfer between mesomeric (ground state) and tautomeric forms (excited state) of 2-hydorxyphenyl benzotriazoles shown in Scheme 10. A feature specific to benzotriazole is that no triplet state is involved during recession of excited to ground state. This explains its high efficiency and good light fastness property as an UV absorber. The UV spectrum can be tuned by changing substituent on the molecule, e.g. a chloro moiety red-shifted the absorption for 10-15 nm. The physical state can also be altered. For example, polyethylene glycol tail makes it water-dispersible,etc.

The main drawback for benzotriazole is its basicity, especially at the excited state (tautomeric form); therefore, it is not suitable for acidic polymers such as fluorinated polymers.

27U

V absorbers

UV absorbers Benzotriazole based

Scheme 10. Various resornance forms of benzotriazole and their associated states. Illustration on the right is a scheme of main radiationless transition on energy dissipation (i.c.=internal conversion; v.r.=vibrational realxation.)

28

UV absorbers

Forms State

Tautomeric Excited

Mesomeric Ground

v.r. proton transfer

i.c.

NN

N

RN

NN

HO

R

NN

NH - O

R

NN

NH O

R

+-

proton transfer

proton transfer

v.r.

+-

HO

+-

UV absorbersBenzotriazole based

Chiguard® P Chiguard® 326

Chiguard® 327 Chiguard® 328

Chiguard® 5411

29U

V absorbers

REACH Status: items listed above are all pre-registered.

NameChiguard® PChiguard® 326Chiguard® 327Chiguard® 328Chiguard® 5411

CAS No.2440-22-43896-11-53864-99-125973-55-13147-75-9

AppearancePale yellow crystalline powderLight yellow powderPale yellow crystalline powderPale yellow crystalline powderOff-white crystalline powder

Melting point128-132 ˚C137-141 ˚C155 ˚C min.79-84 ˚C102-107 ˚C

ApplicationsPVC/Unsaturated polyesterHIPS/SEBS/coatingsABS/HIPSAutomobile coatingPC/PMMA


30

UV absorbers

*All items are measured with this concentration: 2x10-5 g/L

UV absorbersBenzotriazole basedSpeciality

Chiguard® 234

31U

V absorbers

Chiguard® 5530

REACH Status: Chiguard® 5530 and 5431 are registered. Chiguard® 234 is pre-registered. Chiguard® 5571 and 5582 will be registered.

Chiguard® 5582

CH2CH2CO2C8H17

HON

NN

NN

N

HO

CH2CH2CO(OCH2CH2)6-7OH

NameChiguard® 234Chiguard® 5530Chiguard® 5582Chiguard® 5431Chiguard® 5571

CAS No.70321-86-7104810-48-2127519-17-9103597-45-1125304-04-3

AppearanceOff-white crystalline powderYellow to light amber liquidYellow to light amber liquidOff-white crystalline powderViscous clear yellow liquid

Melting point137 - 141 ˚C--195˚C-

ApplicationsNylon, PBTWater-borne, automobile coatingAutomobile coatingPCPUR



Speciality

32

UV absorbers


UV absorbersBenzophenone based

Benzophenone based UV absorbers were the first UV absorbers used in the industries since more than 50 years ago. They are still used in many applications nowadays for economic reasons and unique features such as neutrality and are standard UV filters for acidic resin such as PVC and cosmetic products.

Like benzotriazoles, benzophenones also absorb UV light and dissipate the absorbed energy into harmless heat via proton transfer mechanisms. Unlike benzotriazoles, benzophenones' relaxation from excited state involve triplet states as shown in Scheme 11.This explains the outcome of the shorter light fastness and lower efficiency of benzophenone versus benzotriazole because triplet process takes longer time to relax and is easier to decompose.

The main absorption of simple benzophenone UV absorber like Chiguard® BP-3 is situated in 280 nm and extend to 350 nm. Electronic donating substituent pushes this absorption towards longer wavelengths as shown in the UV spectrum (pg.32) of Chiguard® BP-2. Water solubility benzophenone is also available as Chiguard® BP-4.

33U

V absorbers

UV absorbers Benzophenone based

Scheme 11. Scheme of two resornance forms of benzophenone and their associated states. Illustration on the right is a scheme of main radiationless transition on energy dissipation (i.s.c.=intersystem crossing; v.r.= vibrational realxation.)

34

UV absorbers

O

Proton transfer

OH

H3CO

Forms State

Enol Excited

H3CO

OOH

Pheno

v.r. proton transfer

i.s.c.

i.s.c.

v.r.

v.r.

GroundPheno

UV absorbersBenzophenone based

35U

V absorbers

Chiguard® BP-1 Chiguard® BP-2


REACH Status: all items listed above are all pre-registed except Chiguard® BP-8

NameChiguard® BP-1Chiguard® BP-2Chiguard® BP-3Chiguard® BP-4Chiguard® BP-6Chiguard® BP-8Chiguard® BP-12

CAS No.131-56-6131-55-5131-57-74065-45-6131-54-4131-53-31843-05-6

AppearanceYellow crystalsLight yellow crystalline powderLight yellow crystalline powderOff white powderLight yellow powderLight yellow powderPale yellow crystalline powder

Melting point142 - 145 ˚C195 ˚C min.63 - 65 ˚C107 ˚C min.130 ˚C min.68 ˚C46.5 - 48.5 ˚C

ApplicationsPVCCosmeticsCosmeticsCosmeticsFilmFilmPVC/EVA

UV absorbers Benzophenone based


Chiguard® BP-12

36

UV absorbers


UV absorbersTriazine based

Scheme 12. Proton transfer in 2-hydroxyphenyl triazines.

In the 90’s, an innovative class of UV absorbers was commercialized and quickly dominated the high-end UV absorber market. They are representatives of 2-(2’-hydroxyphenyl)-1, 3,5-triazines shown in Scheme 12, which is characterized by high extinction coefficient compared to benzophenone and benzotriazole. Their energy dissipation mechanism is believed to be attributed to the excited state intramolecular proton transfer, similar to that discussed for benzotriazole. Triazine-based UV absorbers have a superior light fastness property to benzotriazole and benzophenole especially in lipophilic polymers, e.g. PP. Another unique feature is their acidic nature, so they can be used for acidic rain applications or acid-catalyzed systems. The main drawback of trazine is its high cost compared to traditional UV absorbers.

37U

V absorbers

Proton

transfer

Pheno(Ground state)

Keto(Excited state)

UV absorbers Triazine based

38

UV absorbers

Chiguard® 1064 Chiguard® 5405*

Chiguard® 5400*

REACH Status: all items listed above are to be registered.

* Product is still on patent in certain areas of the world.

NameChiguard® 1064Chiguard® 5400*Chiguard® 5405*

CAS No.2725-22-6153519-44-9137658-79-8

AppearanceLight yellow powderLight yellow liquidLight yellow powder

Melting point89 - 91 ˚C-77 - 74 ˚C

ApplicationsPP, PE, TPEAutomobile/UV coatingsEngineering plastics

UV absorbers Triazine based

UV absorbers

40


Contrary to the three UV absorber familes described earlier, compounds introduced here are active not via proton transfer. Among them, both cinnamate-based UV absorber Chiguard® 336 and benzoxazinone-based UV absorber Chiguard® 380 use a large number of possibilities of vibration to transform the absorbed energy into heat. The benzoate type UV absorbers, Chiguard® 5540 and 1908, undergo Fries arrangement and transformation into benzophenone and hindered phenol, thus becoming an UV absorber and an AO (shown in Scheme 13). Oxanilide based Chiguard® 1033 has dual roles as a short wavelength UV filter and an UV quencher. All of the UV absorbers in this system are used only for special applications.

UV absorbersOthers

Scheme 13. Benzoate based UV absorber needs to undergo a Fries rearrangement prior to function as UV absorber and anti-oxidant.

41U

V absorbers

UV

HOO

O

O

O

benzophenone

HOO

HO

hinderedphenol

HO

UV absorbers Others

42

UV absorbers

REACH Status: Chiguard® 5540, 1108, 1033, and 336 are pre-registered. Chiguard® 380 is under registeration.


NameChiguard® 5540Chiguard® 1108Chiguard® 380Chiguard® 1033Chiguard® 336

CAS No.4221-80-167845-93-618600-59-423949-66-86197-30-4

AppearanceWhite crystalline powderWhite to off-white powderOff-white to light yellow powderWhite powderPale yellow liquid

Melting point193 ˚C min.58 ˚C min.300 ˚C min.120 ˚C min.-

ApplicationsPP/PEPP/PEPETAcrylic/PVCPVC

UV absorbersOthers


Chiguard® 336

43U

V absorbers

UV absorbers Others

44

UV absorbers


UV absorbersOthers (formulated)

45U

V absorbers

REACH Status: Chiguard® 3053 and 3253 are registered. Chiguard® 9735 is pre-registered. Chiguard® 1099, U-988, U-800, 8431, and 6447 will be registered.

NameChiguard® 3053Chiguard® 3253Chiguard® 1099Chiguard® U-988Chiguard® U-800Chiguard® 9735Chiguard® 8431Chiguard® 6447

CAS No.--------

AppearancePale yellow liquidPale yellow liquidLight yellow liquidWhite to pale yellow powderLight yellow liquidPale yellow liquidYellow to amber liquidPale yellow powder

Melting point---75 ˚C min.---68 ˚C min.

ApplicationsAcrylic emulsionWood coatingAlkylTPUPU FoamEpoxy flooringSolar filmPP/PE

UV absorbers Others (formulated)

UV absorbers

46


Light stabilizers

Light stabilizersHindered amine light stabilizers

47

HALS, since its commercialization more than 30 years ago, has become the industry standard light stabilizer for many polymers. They do not absorb UV lights above 250 nm, thus can not be considered as an UV absorber or even quencher of the excited state. Numerous mechanisms of stabilization have been proposed since its debut. Among the main mechanisms of stabilization proposed, free radical scavenging, especially carbon-centered radicals scavenging, have attracted the most attention. This mechanism also explains why this class of light stabilizer can be the primary AO as well.

As a radical scavenger, the imine on HALS needs to be transformed into nitroxy radical by oxygen. Nitroxy radical scavenges various radicals efficiently even at ambient temperatures. Remarkably, nitroxy radical can be regenerated during light stabilization process as shown in Scheme 14. Nitroxy radical additionally generated by hydroperoxide oxidation is also another plausible mechanism of stabilization by HALS. Some research shows HALS when becoming nitroxy radical is also an effective UV quencher. With HALS, even if UV light is escaped from the screening of UV absorber and causes photolysis, the damages could still be fixed quickly.

More than 20,000 tons of HALS is consumed every year because they are used heavily in the two largest polymer families, PP and PE. Their lipophilic and high molecular weight structures make them well compatible in PP and PE. Bearing no chromophore makes them inherently colorless and transparent. Its UV stabilization function is not affected by thickness, while UV absorbers are. Therefore they are ideal for film and fiber applications. Combinations of the above advantages also help to explain the large consumption of HALS.

Recent awareness on new HALS design has been shifted to low basicity HALS(e,g. Chiguard® 101) and dual function HALS (e.g. Chiguard® 100) and their synergical blends with UV absorbers(e.g. Chiguard® 6447).

Light stabilizers


48

Scheme 14. Cyclic mechanism involves generating, consuming and regenerating of nitroxy radical.

ROHROOHROOR ROO

HALS

N - HR R N - O N - O - RR

R

nitroxy

radical

49


C8H17 C8H17C8H16

N NO

O

O OO

OON

O O

O NC4H9

OH

REACH Status: Chiguard® 100, 353, 622, 770, and 944 are pre-registered. Chiguard® 101 is registered. Chiguard® 405 and 228 will be registered.

Chiguard® 353

Light stabilizers


NameChiguard® 100Chiguard® 101Chiguard® 228Chiguard® 353Chiguard® 405Chiguard® 622Chiguard® 770Chiguard® 944

CAS No.63843-89-0129757-67-1106990-43-6-124172-53-865447-77-052829-07-970624-18-9

AppearanceWhite powderLight yellow liquidLight yellow crystalline powderLight yellow liquidWhite crystalline powderWhite crystalline powderWhite crystalline powderWhite to off-white granule

Melting point144 ˚C min.-115 - 150 ˚C

-155 - 158 ˚C65 - 80 ˚C80-86 ˚C105 - 135 ˚C

ApplicationsPUAutomobile coatingNon-migrating film applicationAutomobile coating/water borneOlefinOlefinEngineering plasticsOlefin

50

Chiguard® 228



(CH2)2(CH2)2

OO

OO N C C OCH3n

H

CH3

CH3

CH3

CH3

CH3

CH2HN

(CH2)6

H

N

H

N

NN

NN

Nn

HN NH

HN

NH

R

NH2C

H2CH2C

H2C

CH2

CH2

CH2

CH2

N

R

RR

C4H9

N

N

N

N N

N C4H9

C

C

C

C

C

C

C

N

CH

CH2

H2C

H2C

CH

CH3

H2C

CH3

CH3

CH3

CH3

CH3

CH3H3C

H3C

H3C

Where R=

N HH N NN (CH2)6

OHHO

Light stabilizers


Flame retardants

Flame retardantsGeneral

51

Microscopically speaking, ignition per se is a vigirous thermal oxidation which involves a series of radical chain reactions. Both oxygen and heat are required to sustain ignition. Chemicals which can scavenge radicals and block out the heat/oxygen are able to inhibit or retard the spread of fire, and are thus called flame retardants. Over a hundred years of development, there are four types of commercially available flame retardants based on different compositions as shown in the table below. The annual consumption of flame retardants is currently over 1.5 millions tons, which is the eqivalent of a sales volume of approximately 1.8 billion Euro.

Chitec’s flame retardant packages are designed specifically for olefin, and for injection and extrusion processes, used in parts of electrical equipment, cars, airplanes and building components. They are divided into two groups; one is based on halogen, the other is non-halogen. UL94 and oxygen index are the two most commonly used flame retardant tests for evaluating the efficiency of the flame retardancy in our lab.

Table 1. Categories of flame retardants and their functions.

Functions Global consumption by weight (%)

Metal hydroxide and metal oxide heat sink 60%

Halogenated radical scavenger 24%

Phosphorous radical scavenger/thermal shield

15%

Others (nitrogen, silicone, carbon black, ec

various 1%

Family

Flame retardants

Flame retardantsNon-halogen based

53

Olefine type polymer is difficult to increase the flame retardancy by using non-halogenated FRs. For example, for polypropylene, it requires 40-50% of phosphate based FR (by weight) to reach UL94 V-0 grade compared to 15-20% if halogentated based FR is used. Fortunately, there is one type of non-halogen flame retardants called intumescent (originated from Latin meaning “swell up”) FRs which are very effective for olefin. Intumescent FRs upon exposure to heat transform into foam which prevents the heat from spreading and oxygen from getting in.

Intumescent FRs are usually composed of three major ingredients; 1. An inorganic acid;2. A carbon rich material as char former (carbonific);3. A blowing agent-called spumific.

The interaction of these components to form a foamed char is illustrated in figure 1.

A variety of intumescent FRs are commercially available. A suitable intumescent FR has to be low in dosage and does not alter the mechanical properties.

Figure 1. Left is the powder form before the reaction, and right is the form after the reaction.

Flame retardants

Flame retardantsNon-haolgen based

54

Zuran® 808 compared to other commercial intumescents FR bears the following advantages:

1. Low loading required to reach UL94 V-0. (e.g. 20-23% Zuran 808 vs. 20-30% traditional intumescent FRs)2. High process tempearure up to 250 ˚C.3. Minor impact on mechanical properties.

REACH Status: Zuran® 808 will be registered.

NameZuran® 808

CAS No.proprietary

AppearanceWhite powder

ApplicationsPP/PE/TPE

Melting point> 260˚C

Flame retardants

Flame retardantsHalogen based

Brominated flame retardants

55

Halogenated flame retardants are the second largest FR families in terms of volume. They are broad spectrum FRs and can be used for any polymers. Their FR mechanism is via radicals quenching with dense halogenated radicals. They have strong synergic effect with antimony oxides. They are dominating the UL94 V-2 applications where only 3~5% halogenated FR is required along with 1-2% Sb2O3. More than 20 halogenated FRs are commercially available. Chitec supplies only brominated FR designed for olefin polymer, especially non-migratory and V-2 applications.

Halogenated flame retardants have been under scrutiny for years due to their bio-accumulating and ozone depleting effect. European RoHS regulation had recently started to ban some commodity brominated FRs used in goods. In addition to environmental concern, the price of the brominated FR has soared since early 2009 due to bromine shortage. The combined effect of regulation and price make halogenated FR targets to replace. For example, flame-retardant grade bisphenol A expoxy used completely brominated FR as flame retardant in 2005, but just three years later in 2008, 8% of brominated FR was replaced by phoshporous based FR.

REACH Status: Chitex® 900 and 920 are pre-registered. Chitex® 950 will be registered.

NameChitex® FR-900Chitex® FR-920Chitex® FR-950

CAS No.21850-44-242757-55-119186-97-1

AppearanceWhite powderOff-white powderWhite powder

Melting point98 ˚C min.100 ˚C min.175 ˚C min.

ApplicationsPP/PEPP/PEPP/PE

Bromine content66% min.64% min.68% min.

Flame retardants

Flame retardantsHalogen based

Brominated flame retardants

56

Chitex® FR-900

Chitex® FR-950

C(CH2Br)3

C(CH2Br)3

(BrH2C)3C

O

OOO P

Chitex® FR-920

H2C C C O

BrBr

BrBr

O C C CH2

Br BrBrBr

HH

H

HH

H

CH3

CH3

BrBr

BrBr

S

O

O

O C C CH2

Br Br

HH

HH2C C C O

BrBr

HH

H

Available packagings

Available packaging

57

IBC tank1000kgs

Fiber drum20~100kgs

Gaylord400~500kgs

Iron drum100~200kgs

Carton box20~50kgs

Plastic drum20~30kgs

Paper bag20~25kgs

Physical appearances

Physical appearances

58

Powder

Crystalline powder

Flake

Granules

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