WO2009112425A1

WO2009112425A1 - An optical film for a flat panel display

Info

Publication number: WO2009112425A1
Application number: PCT/EP2009/052614
Authority: WO
Inventors: Daisuke Fujiki; Markus Grob
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2008-03-12
Filing date: 2009-03-05
Publication date: 2009-09-17
Anticipated expiration: 2010-09-12
Also published as: TWI560224B; JP2011518343A; JP5669584B2; TW201000535A; KR101618890B1; KR20110000562A

Abstract

An optical film for a flat panel display comprising the components (A) a thermoplastic polymer; (B) a mixture containing two or more different compounds selected from the group consisting of the compounds of the formulae (B-I) and (B-II); wherein E₁ is hydrogen, C₁-C₁₈alkyl, C₁-C₁₈alkyl substituted by 1, 2 or 3 radicals selected from the group consisting of -OH, C₂-C₁₈alkenyloxy, -C(O)OX₁ and -OC(O)X₂ with X₁ and X₂ being independently C₁-C₁₈alkyl; C₃-C₅₀alkyl interrupted by oxygen or C₃-C₅₀hydroxyalkyl interrupted by oxygen; E₂, E₃, E₄ and E₅ are independently hydrogen, C₁-C₁₈alkyl, phenyl or phenyl substituted by 1, 2 or 3 C₁-C₄alkyl; wherein A₁, A₂, A₃ and A₄ are independently hydrogen, C₁-C₁₈alkyl, C₁-C₁₈alkyl substituted by 1, 2 or 3 radicals selected from the group consisting of -OH, C₂-C₁₈alkenyloxy, -C(O)OY₁ and -OC(O)Y₂ with Y₁ and Y₂ being independently C₁-C₁₈alkyl; C₃-C₅₀alkyl interrupted by oxygen or C₃-C₅₀hydroxyalkyl interrupted by oxygen; and optionally (C) at least one 2,2,6,6-tetramethylpiperidine derivative.

Description

An optical film for a flat panel display

The present invention relates to an optical film for a flat panel display, containing a thermoplastic polymer, two or more different hydroxyphenyltriazines and optionally a 2,2,6,6- tetramethylpiperidine derivative, a flat panel display containing said optical film, the use of two or more different hydroxyphenyltriazines for improving the UV resistance of an optical film and a composition containing a thermoplastic polymer, two or more different UV absorbers and optionally a 2,2,6,6-tetramethylpiperidine derivative.

Optical films for displays are described for example in JP-A-2007/217667 and US-A-2007/0160828.

The present invention relates in particular to an optical film for a flat panel display comprising the components

(A) a thermoplastic polymer;

(B) a mixture containing two or more (preferably two) different compounds selected from the group consisting of the compounds of the formulae (B-I) and (B-Il);

wherein E₁ is hydrogen, CrCi₈alkyl, d-Ci₈alkyl substituted by 1 , 2 or 3 radicals selected from the group consisting of -OH, C₂-Ci8alkenyloxy, -C(O)OXi and -OC(O )X₂ with X₁ and X₂ being independently d-Ci₈alkyl; C₃-C₅₀alkyl interrupted by oxygen or C₃-C₅₀hydroxyalkyl interrupted by oxygen; E₂, E₃, E₄ and E₅ are independently hydrogen, CrCi₈alkyl, phenyl or phenyl substituted by 1 , 2 or 3 C_rC₄alkyl;

wherein A₁, A₂, A₃ and A₄ are independently hydrogen, CrCi₈alkyl, d-Ci₈alkyl substituted by 1 , 2 or 3 radicals selected from the group consisting of -OH, C₂-Ci₈alkenyloxy, -C(O)OYi and -OC(O)Y₂ with Y₁ and Y₂ being independently d-Ci₈alkyl; C₃-C₅₀alkyl interrupted by oxygen or C₃-C₅ohydroxyalkyl interrupted by oxygen; and optionally (C) at least one 2,2,6,6-tetramethylpiperidine derivative.

Examples of Ci-Ci₈alkyl are methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert- butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1 -methylpentyl, 1 ,3-dimethylbutyl, n-hexyl, 1 -methyl- hexyl, n-heptyl, isoheptyl, 1 ,1 ,3,3-tetramethylbutyl, 1 -methylheptyl, 3-methylheptyl, n-octyl, 2- ethylhexyl, 1 ,1 ,3-trimethylhexyl, 1 ,1 ,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1 -methyl- undecyl, dodecyl, 1 ,1 ,3,3,5,5-hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. CrC₈alkyl, for example methyl, n-butyl, 2-ethylhexyl or an isomeric mixtue of octyl, is particularly preferred.

Preferred examples of Ci-Ci₈alkyl, preferably C₃-Ci₈ alkyl, substituted by 1 , 2 or 3 radicals selected from the group consisting of -OH, C₂-Ci₈alkenyloxy, -C(O)OXi (or -C(O)OYi) and

^CH 3 CH₃ -OC(O)X₂ (or -OC(O)Y₂) are 2-hydroxyethyl — CH—C—O— C₈H₁₇ or — _CH— O— C— C H ■

I l Ii ^{8 17} o o

An example of C₃-C₅oalkyl interrupted by one or more oxygen is -(CH₂CH₂-O-)₃-CH₃.

Preferred examples of C₃-C₅ohydroxyalkyl interrupted by oxygen are CH-C₄H₉-H .

A preferred example of phenyl substituted by 1 , 2 or 3 CrC₄alkyl is 2,4-dimethylphenyl. Examples of a thermoplastic polymer are

1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, po- lybut-1-ene, poly-4-methylpent-1-ene, polyvinylcyclohexane, polyisoprene or polybutadiene, as well as polymers of cycloolefins, for instance of cyclopentene or norbornene, polyethylene (which optionally can be crosslinked), for example high density polyethylene (HDPE), high density and high molecular weight polyethylene (HDPE-HMW), high density and ultrahigh molecular weight polyethylene (HDPE-UHMW), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), (VLDPE) and (ULDPE).

Polyolefins, i.e. the polymers of monoolefins exemplified in the preceding paragraph, preferably polyethylene and polypropylene, can be prepared by different, and especially by the following, methods:

a) radical polymerisation (normally under high pressure and at elevated temperature).

b) catalytic polymerisation using a catalyst that normally contains one or more than one metal of groups IVb, Vb, VIb or VIII of the Periodic Table. These metals usually have one or more than one ligand, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either π- or σ-coordinated. These metal complexes may be in the free form or fixed on substrates, typically on activated magnesium chloride, titanium(lll) chloride, alumina or silicon oxide. These catalysts may be soluble or insoluble in the polymerisation medium. The catalysts can be used by themselves in the polymerisation or further activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyloxanes, said metals being elements of groups Ia, Na and/or Ilia of the Periodic Table. The activators may be modified conveniently with further ester, ether, amine or silyl ether groups. These catalyst systems are usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).

2. Mixtures of the polymers mentioned under 1 ), for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of different types of polyethylene (for example LDPE/HDPE). 3. Copolymers of monoolefins and diolefins with each other or with other vinyl monomers, for example ethylene/propylene copolymers, linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylene/but-1-ene copolymers, propylene/isobutylene copolymers, ethylene/but-1-ene copolymers, ethylene/hexene copolymers, ethylene/methylpentene copolymers, ethylene/heptene copolymers, ethylene/octene copolymers, ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin copolymers (e.g. ethylene/norbornene like COC), ethylene/1 -olefins copolymers, where the 1 -olefin is generated in-situ; propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethylene/vi- nylcyclohexene copolymers, ethylene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers or ethylene/acrylic acid copolymers and their salts (ionomers) as well as terpolymers of ethylene with propylene and a diene such as hexadiene, dicyclopentadiene or ethylidene-norbornene; and mixtures of such copolymers with one another and with polymers mentioned in 1 ) above, for example polypropylene/ethy- lene-propylene copolymers, LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene- acrylic acid copolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random polyal- kylene/carbon monoxide copolymers and mixtures thereof with other polymers, for example polyamides.

4. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).

5. Aromatic homopolymers and copolymers derived from vinyl aromatic monomers including styrene, α-methylstyrene, all isomers of vinyl toluene, especially p-vinyltoluene, all isomers of ethyl styrene, propyl styrene, vinyl biphenyl, vinyl naphthalene, and vinyl anthracene, and mixtures thereof. Homopolymers and copolymers may have any stereostructure including syndiotactic, isotactic, hemi-isotactic or atactic; where atactic polymers are preferred. Ste- reoblock polymers are also included.

5a. Copolymers including aforementioned vinyl aromatic monomers and comonomers selec- ted from ethylene, propylene, dienes, nitriles, acids, maleic anhydrides, maleimides, vinyl acetate and vinyl chloride or acrylic derivatives and mixtures thereof, for example styrene/bu- tadiene, styrene/acrylonitrile, styrene/ethylene (interpolymers), styrene/alkyl methacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic anhydride, styrene/acrylonitrile/methyl acrylate; mixtures of high impact strength of styrene copo- lymers and another polymer, for example a polyacrylate, a diene polymer or an ethylene/pro- pylene/diene terpolymer; and block copolymers of styrene such as styrene/butadiene/sty- rene, styrene/isoprene/styrene, styrene/ethylene/butylene/styrene or styrene/ethylene/propy- lene/styrene.

5b. Hydrogenated aromatic polymers derived from hydrogenation of polymers mentioned under 5.), especially including polycyclohexylethylene (PCHE) prepared by hydrogenating atactic polystyrene, often referred to as polyvinylcyclohexane (PVCH).

5c. Hydrogenated aromatic polymers derived from hydrogenation of polymers mentioned under 5a.).

Homopolymers and copolymers may have any stereostructure including syndiotactic, isotac- tic, hemi-isotactic or atactic; where atactic polymers are preferred. Stereoblock polymers are also included.

6. Graft copolymers of vinyl aromatic monomers such as styrene or α-methylstyrene, for example styrene on polybutadiene, styrene on polybutadiene-styrene or polybutadiene-acry- lonitrile copolymers; styrene and acrylonitrile (or methacrylonitrile) on polybutadiene; styrene, acrylonitrile and methyl methacrylate on polybutadiene; styrene and maleic anhydride on polybutadiene; styrene, acrylonitrile and maleic anhydride or maleimide on polybutadiene; styrene and maleimide on polybutadiene; styrene and alkyl acrylates or methacrylates on polybutadiene; styrene and acrylonitrile on ethylene/propylene/diene terpolymers; styrene and acrylonitrile on polyalkyl acrylates or polyalkyl methacrylates, styrene and acrylonitrile on acrylate/butadiene copolymers, as well as mixtures thereof with the copolymers listed under 5), for example the copolymer mixtures known as ABS, MBS, ASA or AES polymers.

7. Polymers derived from α,β-unsatu rated acids and derivatives thereof such as polyacry- lates and polymethacrylates; polymethyl methacrylates, polyacrylamides and polyacryloni- triles, impact-modified with butyl acrylate.

8. Copolymers of the monomers mentioned under 7) with each other or with other unsaturated monomers, for example acrylonitrile/ butadiene copolymers, acrylonitrile/alkyl acrylate copolymers, acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide copolymers or acry- lonitrile/ alkyl methacrylate/butadiene terpolymers.

9. Polymers derived from unsaturated alcohols and amines or the acyl derivatives or acetals thereof, for example polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl butyral, polyallyl phthalate or polyallyl melamine; as well as their copolymers with olefins mentioned in 1 ) above.

10. Polyacetals such as polyoxymethylene and those polyoxymethylenes which contain ethylene oxide as a comonomer; polyacetals modified with thermoplastic polyurethanes, acrylates or MBS.

1 1. Polyphenylene oxides and sulfides, and mixtures of polyphenylene oxides with styrene polymers or polyamides.

12. Polyesters derived from dicarboxylic acids and diols and/or from hydroxycarboxylic acids or the corresponding lactones, for example polyethylene terephthalate, polybutylene tereph- thalate, poly-1 ,4-dimethylolcyclohexane terephthalate, polyalkylene naphthalate (PAN) and polyhydroxybenzoates, as well as block copolyether esters derived from hydroxyl-terminated polyethers; and also polyesters modified with polycarbonates or MBS.

13. Polycarbonates and polyester carbonates.

14. Natural polymers such as cellulose, rubber, gelatin and chemically modified homologous derivatives thereof, for example cellulose acetates, cellulose propionates and cellulose butyrates, or the cellulose ethers such as methyl cellulose; as well as rosins and their derivatives.

15. Blends of the aforementioned polymers (polyblends), for example PP/EPDM, PoIy- amide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS, PBTP/ABS, PC/ASA,

PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA 6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or PBT/PET/PC. Preferred thermoplastic polymers are those listed above under items 3, 4, 5, 5a, 6 and 12 to 14.

One embodiment of the present invention which is of interest is an optical film wherein component (A) is a polystyrene, a styrene copolymer, a cyclic olefin homopolymer, a cyclic olefin copolymer, a polyester, a polycarbonate or a cellulose derivative, in particular a styrene/methyl methacrylate copolymer, a poly(methyl methacrylate), a cyclic olefin polymer or a triacetyl cellulose.

One of the preferred styrene copolymers is obtained by the polymerization of two or more different styrene monomers. The styrene monomers may be unsubstituted or substituted styrenes. Examples of the substituted styrenes include halogenated styrenes such as chlorostyrene and bromostyrene, and alkyl styrenes such as vinyltoluene and α- methylstyrene.

One preferred styrene/methyl methacrylate copolymer comprises 20% by weight to 95% by weight of the styrene monomer unit and 80% by weight to 5% by weight of the methyl methacrylate unit, preferably 70% by weight or more of the styrene monomer unit and 30% by weight or less of the methyl methacrylate unit.

A norbornene based resin or a maleimide base resin is also preferred as present Component (A).

A further preferred embodiment of the present invention is an optical film wherein component (B) is a mixture of a compound of the formula (B-I) and a compound of the formula (B-Il).

The compound of the formula (B-I) is preferably a compound of the formula (B-l-a), (B-l-b), (B-1-c), (B-l-d), (B-l-e) or (B-l-f).

(B-l-d)

The compound of the formula (B-Il) is preferably a compound of the formula (B-ll-a), (B-ll-b) or (B-Il-C).

A particularly preferred embodiment of the present invention relates to an optical film wherein component (B) is a mixture of the compounds (B-l-a) and (B-ll-b) or a mixture of the compounds (B-l-c) and (B-ll-c).

The compounds of the formulae (B-I) and (B-Il) are essentially known and can be prepared in analogy to known methods, e.g. as described in US-A-6,060,543. Some compounds are commercially available.

Preferred commercially available compounds of the formula (B-I) are TINUVI N^®479, TINUVIN^®1577, TINUVIN^®411 , TINUVIN^®400 and TINUVIN^®405.

Preferred commercially available compounds of the formula (B-Il) are TINOSORB^®S, TINUVIN^®460 and TINUVIN^®477.

Examples of Component (C) are carbonic acid bis(1-undecyloxy-2,2,6,6-tetramethyl-4- piperidyl)ester, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(2,2,6,6-tetramethyl-4- piperidyl)succinate, bis(1 ,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-octyloxy-2, 2,6,6- tetramethyl-4-piperidyl)sebacate, bis(1 ,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert- butyl-4-hydroxybenzylmalonate, the condensate of 1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4- hydroxypiperidine and succinic acid, linear or cyclic condensates of N,N'-bis(2,2,6,6- tetramethyl-4-piperidyl)hexamethylenediamine and 4-tert-octylamino-2,6-dichloro-1 ,3,5- triazine, tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate, tetrakis(2,2,6,6-tetramethyl-4- piperidyl)-1 ,2,3,4-butanetetracarboxylate, 1 ,1'-(1 ,2-ethanediyl)-bis(3,3,5,5-tetrame- thylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2,2,6,6-tetramethyl- piperidine, bis(1 , 2,2,6, 6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)- malonate, 3-n-octyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4.5]decane-2,4-dione, bis(1 -octyl- oxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succi- nate, linear or cyclic condensates of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylene- diamine and 4-morpholino-2,6-dichloro-1 ,3,5-triazine, the condensate of 2-chloro-4,6-bis(4-n- butylamino-2,2,6,6-tetramethylpiperidyl)-1 ,3,5-triazine and 1 ,2-bis(3-aminopropylamino)- ethane, the condensate of 2-chloro-4,6-di-(4-n-butylamino-1 ,2,2,6,6-pentamethylpiperidyl)- 1 ,3,5-triazine and 1 ,2-bis(3-aminopropylamino)ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetrame- thyl-1 ,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyr- rolidine-2,5-dione, 3-dodecyl-1-(1 ,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensate of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6- dichloro-1 ,3,5-triazine, a condensate of 1 ,2-bis(3-aminopropylamino)ethane and 2,4,6- trichloro-1 ,3,5-triazine as well as 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [136504-96-6]); a condensate of 1 ,6-hexanediamine and 2,4, 6-trichloro-1 ,3,5-triazine as well as N,N-dibutylamine and 4-butylamino-2,2,6,6-tetramethylpiperidine (CAS Reg. No. [192268- 64-7]); N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimide, N-(1 ,2,2,6,6-pentamethyl-4- piperidyl)-n-dodecylsuccinimide, 2-undecyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro- [4,5]decane, a reaction product of 7,7,9, θ-tetramethyl^-cycloundecyl-i-oxa-S.δ-diaza^-oxo- spiro-[4,5]decane and epichlorohydrin, 1 ,1-bis(1 ,2,2,6, 6-pentamethyl-4- piperidyloxycarbonyl)-2-(4-methoxyphenyl)ethene, N,N'-bis-formyl-N,N'-bis(2,2,6,6- tetramethyl-4-piperidyl)hexamethylenediamine, a diester of 4-methoxymethylenemalonic acid with 1 ,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly[methylpropyl-3-oxy-4-(2, 2,6,6- tetramethyl-4-piperidyl)]siloxane, a reaction product of maleic acid anhydride-α-olefin copolymer with 2,2,6,6-tetramethyl-4-aminopiperidine or 1 ,2,2,6,6-pentamethyl-4- aminopiperidine, 2,4-bis[N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4-yl)-N- butylamino]-6-(2-hydroxyethyl)amino-1 ,3,5-triazine, 1-(2-hydroxy-2-methylpropoxy)-4- octadecanoyloxy-2,2,6,6-tetramethylpiperidine, 5-(2-ethylhexanoyl)oxymethyl-3,3,5-trimethyl- 2-morpholinone, Sanduvor (Clariant; CAS Reg. No. 106917-31-1], 5-(2- ethylhexanoyl)oxymethyl-3,3,5-trimethyl-2-morpholinone, the reaction product of 2, 4-bis[(1- cyclohexyloxy^^^^-piperidine^-y^butylaminoj-θ-chloro-s-triazine with N,N'-bis(3-ami- nopropyl)ethylenediamine), 1 ,3,5-tris(N-cyclohexyl-N-(2,2,6,6-tetramethylpiperazine-3-one-4- yl)amino)-s-triazine, 1 ,3,5-tris(N-cyclohexyl-N-(1 ,2,2,6,6-pentamethylpiperazine-3-one-4-yl)- amino)-s-triazine. Component (C) is preferably a compound of the formula (C-l-a), (C-l-b), (C-l-c), (C-l-d) (C-I (C-III) or (C-IV)

wherein bi is a number from 2 to 20, preferably 2 to 20, and the radicals Ri are independently hydrogen, Ci-C₈alkyl, O, -OH, -CH₂CN, d-Ci₈alkoxy, C₅-Ci₂cycloalkoxy, C₃-C₆alkenyl, C₇-C₉phenylalkyl unsubstituted or substituted on the phenyl by 1 , 2 or 3 Ci-C₄alkyl; or d-C₈acyl;

wherein the radicals R₂ have independently one of the meanings of Ri

(C-III) wherein b₂ is 2 to 20 and the radicals R₃ have independently one of the meanings of Ri;

wherein R₄ is hydrogen or CrC₄alkyl, R₅ is a direct bond or Ci-Ci_Oalkylene, and b₃ is a number from 2 to 20. Examples of alkyl having up to 8 carbon atoms are methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, 2-ethylbutyl, n-pentyl, isopentyl, 1-methylpentyl, 1 ,3-dimethyl- butyl, n-hexyl, 1-methylhexyl, n-heptyl, isoheptyl, 1 ,1 ,3,3-tetramethylbutyl, 1-methylheptyl, 3- methylheptyl, n-octyl, 2-ethylhexyl. CrC₄alkyl, in particular methyl, is preferred.

Preferred examples of Ci-Ci₈alkoxy, e.g. Ci-C₈alkoxy, are methyoxy, propoxy and octoxy.

A preferred example of C₅-Ci₂cycloalkoxy is cyclohexyloxy.

Examples of C₃-C₆alkenyl are allyl, 2-methallyl, butenyl, pentenyl and hexenyl. AIIyI is preferred. The carbon atom in position 1 is preferably saturated.

Examples of Cr-Cgphenylalkyl unsubstituted or substituted on the phenyl by 1 , 2 or 3 Ci-C₄alkyl are benzyl, phenylethyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl and tert- butylbenzyl.

Examples of Ci-C₈acyl are formyl, acetyl, propionyl, butyryl, pentanoyl, hexanoyl, heptanoyl, octanoyl, acryloyl, methacryloyl and benzoyl. Ci-C₈Alkanoyl, C₃-C₈alkenyl and benzoyl are preferred. Acetyl and acryloyl are especially preferred.

Examples of C-i-C-ioalkylene are methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, 2,2-dimethyltrimethylene, hexamethylene, trimethylhexamethylene, octamethylene and decamethylene.

Ri is preferably hydrogen, methyl or propoxy.

R₂ is preferably methyl.

R₃ and R₄ are preferably hydrogen.

R₅ is preferably ethylene. The compounds of Component (C) are essentially known and can be prepared in analogy to known methods, as e.g. described in US-A-4,086,204, US-A-6,046,304, US-A-4,331 ,586, US-A-4,108,829, US-A-4,477,615 and US-A-4,233,412.

Preferred commercially available compounds of Component (C) are CHIMASSORB^®944, CHIMASSORB^®2020, DASTIB^®1082, CYASO RB^®UV3346, CYASORB^®UV3529, CHIMASSORB^®119, UVASORB^®HA 88 and TINUVIN^®622.

The meanings of the terminal groups which saturate the free valences in the compounds of the formulae (C-l-a), (C-l-b), (C-l-c), (C-l-d), (C-Il), (C-III) and (C-IV) depend on the processes used for their preparation. The terminal groups can also be modified after the preparation of the compounds.

If the compounds of the formula (C-l-a), (C-l-b), (C-l-c) or (C-l-d) are prepared by reacting a correspondingly substituted 2,5-dichlorotriazine with a diamine compound of the formula

the terminal group bonded to the diamino radical is hydrogen or a correspondingly substituted triazinyl residue, e.g. in the case of the formula (C-1-a) the group

-Cl

CH, CH,

-CH,

CH, CH, and the terminal group bonded to the triazine radical is Cl or the group

It may be advantageous to replace the -Cl, for example, by -OH or an amino group when the reaction is complete. Examples of amino groups which may be mentioned are pyrrolidin-1-yl, morpholino, -NH₂, -N(Ci-C8alkyl)₂ and -NR(Ci-C8alkyl), in which R is hydrogen or a 2,2,6,6- tetramethyl-4-piperidyl group.

In the compounds of the formula (lll-c) the terminal group bonded to the triazine radical is, for

example, Cl or a group, and the terminal group bonded to the amino

radical is, for example, hydrogen or a group.

If the compounds of the formula (C-IV) are prepared, for example, by reacting a compound of

the formula with a dicarboxylic acid diester of the formula

Y_O-OOC-R₅-COO-Y_O, in which Y₀ is, for example, methyl, ethyl or propyl, the terminal group bonded to the 2,2,6,6-tetramethyl-4-oxypiperidin-1-yl radical is hydrogen Or -CO-R₅-COO-Y₀,

and the terminal group bonded to the diacyl radical is -0-Y₀ or .

Particularly preferred compounds of Component (C) are

wherein bi is 2 to 20 in the formulae (C-l-a-1 ), (C-l-b-1 ), (C-l-c-1 ), (C-l-d-1 ) and (C-l-d-2),

(C-I I l-a) wherein b₂ is 2 to 20;

wherein b₃ is a number from 2 to 20.

One of the particularly preferred compounds of the formula (C-l-b) is

The preparation of this compound is described in Example 10 of US-A-6,046,304.

A preferred embodiment of the present invention relates to an optical film containing the components (A), (B) and (C).

If desired, the optical film of the present invention may further contain one or more conventional additives. Suitable examples are listed in the following.

1. Antioxidants

1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-di- methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-bu- tyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(α-methylcyclohexyl)-4,6-dimethyl- phenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-meth- oxymethylphenol, nonylphenols which are linear or branched in the side chains, for example, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6-(1 '-methylundec-1 '-yl)phenol, 2,4-dimethyl-6-(1 '- methylheptadec-1 '-yl)phenol, 2,4-dimethyl-6-(1'-methyltridec-1'-yl)phenol and mixtures thereof.

1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctyl- thiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-di-dodecylthiomethyl-4- nonylphenol. 1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4-methoxy- phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octade- cyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-bu- tyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis(3,5-di-tert-butyl-4-hy- droxyphenyl) adipate.

1.4. Tocopherols, for example α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures thereof (vitamin E).

1.5. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2- methylphenol), 4,4'-thiobis(3,6-di-sec-amylphenol), 4,4'-bis(2,6-dimethyl-4-hydroxyphenyl)- disulfide.

1.6. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tert-butyl-4-methylphenol), 2,2'- methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(α-methylcyclohexyl)- phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4- methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis(4,6-di-tert-butyl- phenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis[6-(α-methylben- zyl)-4-nonylphenol], 2,2'-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol], 4,4'-methy- lenebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tert-butyl-2-methylphenol), 1 ,1-bis(5-tert- butyl-4-hydroxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4- methylphenol, 1 , 1 ,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane, 1 , 1 -bis(5-tert-butyl-4- hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3'-tert- butyl-4'-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopenta- diene, bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephtha- late, 1 ,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane, 2,2-bis(3,5-di-tert-butyl-4-hydroxyphe- nyl)propane, 2,2-bis(5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane,

1 ,1 ,5,5-tetra-(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7. Q-, N- and S-benzyl compounds, for example 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxydi- benzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tridecyl-4-hydroxy- 3,5-di-tert-butylbenzylmercaptoacetate, tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine, bis(4- tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxy- benzyl)sulfide, isooctyl-S^-di-tert-butyM-hydroxybenzylmercaptoacetate.

1.8. Hydroxybenzylated malonates, for example dioctadecyl-2,2-bis(3,5-di-tert-butyl-2-hy- droxybenzyl)malonate, di-octadecyl-2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate, di- dodecylmercaptoethyl-2,2-bis (3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis[4-(1 ,1 ,3,3-te- tramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.9. Aromatic hydroxybenzyl compounds, for example 1 ,3,5-tris(3,5-di-tert-butyl-4-hydroxy- benzyl)-2,4,6-trimethylbenzene, 1 ,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetrame- thylbenzene, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.

1.10. Triazine compounds, for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxy- anilino)-1 ,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1 ,3,5-tri- azine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1 ,3,5-triazine, 2,4,6-tris- (3,5-di-tert-butyl-4-hydroxyphenoxy)-1 ,2,3-triazine, 1 ,3,5-tris(3,5-di-tert-butyl-4-hydroxyben- zyl)isocyanurate, 1 ,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, 2,4,6-tris- (3, 5-di-tert-butyl-4-hydroxyphenylethyl)-1 ,3,5-triazine, 1 ,3,5-tris(3,5-di-tert-butyl-4-hydroxy- phenylpropionyl)-hexahydro-1 ,3,5-triazine, 1 ,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)iso- cyanurate.

1.1 1. Benzylphosphonat.es, for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphospho- nate, diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate, dioctadecyl3,5-di-tert-butyl-4-hy- droxybenzylphosphonate, dioctadecyl-δ-tert-butyl^-hydroxy-S-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

1.12. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N- (3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

1.13. Esters of β-(3,5-di-tert-butyl-4-hvdroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1 ,6-hexanediol, 1 ,9- nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethy- lene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hy- droxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylol- propane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.14. Esters of β-(5-tert-butyl-4-hvdroxy-3-methylphenyl)propionic acid with mono- or poly- hydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1 ,6-hexanedi- ol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis- (hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethyl- olpropane, 4-hydroxymethyl-1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane; 3,9-bis[2-{3-(3-tert- butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1 ,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]- undecane.

1.15. Esters of β-(3,5-dicvclohexyl-4-hvdroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1 ,6-hexanediol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)ox- amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy- droxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.16. Esters of 3,5-di-tert-butyl-4-hvdroxyphenyl acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1 ,6-hexanediol, 1 ,9-nonanediol, ethylene glycol, 1 ,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)ox- amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy- droxymethyl-1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.17. Amides of β-(3,5-di-tert-butyl-4-hvdroxyphenyl)propionic acid e.g. N,N'-bis(3,5-di-tert- butyl-4-hydroxyphenylpropionyl)hexamethylenediamide, N,N'-bis(3,5-di-tert-butyl-4-hydroxy- phenylpropionyl)trimethylenediamide, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hy- drazide, N,N'-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide (Nau- gard^®XL-1 , supplied by Uniroyal).

1.18. Ascorbic acid (vitamin C) 1.19. Aminic antioxidants, for example N,N'-di-isopropyl-p-phenylenediamine, N,N'-di-sec-bu- tyl-p-phenylenediamine, N,N'-bis(1 ,4-dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3- methylpentyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-dicy- clohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-bis(2-naphthyl)-p- phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1 ,3-dimethylbutyl)-N'-phe- nyl-p-phenylenediamine, N-(1 -methylheptyl)-N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'- phenyl-p-phenylenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N'-dimethyl-N,N'-di- sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4-isopropoxydiphenyl- amine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phenyl-2-naph- thylamine, octylated diphenylamine, for example p,p'-di-tert-octyldiphenylamine, 4-n-butyl- aminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol, 4- octadecanoylaminophenol, bis(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dimethylamino- methylphenol, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, N,N,N',N'-tetra- methyl-4,4'-diaminodiphenylmethane, 1 ,2-bis[(2-methylphenyl)amino]ethane, 1 ,2-bis(phenyl- amino)propane, (o-tolyl)biguanide, bis[4-(1',3'-dimethylbutyl)phenyl]amine, tert-octylated N- phenyl-1-naphthylamine, a mixture of mono- and dialkylated tert-butyl/tert-octyldiphenyl- amines, a mixture of mono- and dialkylated nonyldiphenylamines, a mixture of mono- and dialkylated dodecyldiphenylamines, a mixture of mono- and dialkylated isopropyl/isohexyl- diphenylamines, a mixture of mono- and dialkylated tert-butyldiphenylamines, 2,3-dihydro- 3,3-dimethyl-4H-1 ,4-benzothiazine, phenothiazine, a mixture of mono- and dialkylated tert- butyl/tert-octylphenothiazines, a mixture of mono- and dialkylated tert-octyl-phenothiazines, N-allylphenothiazine, N,N,N',N'-tetraphenyl-1 ,4-diaminobut-2-ene.

2. UV absorbers and light stabilizers

2.1. 2-(2'-Hvdroxyphenyl)benzotriazoles, for example 2-(2'-hydroxy-5'-methylphenyl)-benzo- triazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert-butyl-2'-hydroxyphe- nyl)benzotriazole, 2-(2'-hydroxy-5'-(1 ,1 ,3,3-tetramethylbutyl)phenyl)benzotriazole, 2-(3',5'-di- tert-butyl-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-methylphe- nyl)-5-chloro-benzotriazole, 2-(3'-sec-butyl-5'-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'- hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hydroxyphenyl)benzotriazole, 2-(3',5'-bis-(α,α-dimethylbenzyl)-2'-hydroxyphenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy- 5'-(2-octyloxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyl- oxy)-carbonylethyl]-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2- methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-meth- oxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonyl- ethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonylethyl]-2'-hydroxy- phenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3'-tert-butyl- 2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)phenylbenzotriazole, 2,2'-methylene-bis[4-(1 ,1 ,3,3- tetramethylbutyl)-6-benzotriazole-2-ylphenol]; the transesterification product of 2-[3'-tert-bu- tyl-5'-(2-methoxycarbonylethyl)-2'-hydroxyphenyl]-2H-benzotriazole with polyethylene glycol

300; [R-CH₂CH₂-COO-CH₂CH₂-^- , where R = 3'-tert-butyl-4'-hydroxy-5'-2H-benzotri-

azol-2-ylphenyl, 2-[2'-hydroxy-3'-(α,α-dimethylbenzyl)-5'-(1 ,1 ,3,3-tetramethylbutyl)-phenyl]- benzotriazole; 2-[2'-hydroxy-3'-(1 ,1 ,3,3-tetramethylbutyl)-5'-(α,α-dimethylbenzyl)-phenyl]ben- zotriazole.

2.2. 2-Hvdroxybenzophenones, for example the 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyl- oxy, 4-dodecyloxy, 4-benzyloxy, 4,2',4'-trihydroxy and 2'-hydroxy-4,4'-dimethoxy derivatives.

2.3. Esters of substituted and unsubstituted benzoic acids, for example 4-tert-butyl-phenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoyl resorcinol, bis(4-tert-butylben- zoyl)resorcinol, benzoyl resorcinol, 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzo- ate, hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxyben- zoate, 2-methyl-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

2.4. Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate, isooctyl α-cyano-β,β-diphe- nylacrylate, methyl α-carbomethoxycinnamate, methyl α-cyano-β-methyl-p-methoxycinna- mate, butyl α-cyano-β-methyl-p-methoxy-cinnamate, methyl α-carbomethoxy-p-methoxycin- namate, N-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline, neopentyl tetra(α-cyano-β,β-di- phenylacrylate.

2.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis[4-(1 ,1 ,3,3-tetramethyl- butyl)phenol], such as the 1 :1 or 1 :2 complex, with or without additional ligands such as n- butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel dibutyldithiocarbamate, nickel salts of the monoalkyl esters, e.g. the methyl or ethyl ester, of 4-hydroxy-3,5-di-tert- butylbenzylphosphonic acid, nickel complexes of ketoximes, e.g. of 2-hydroxy-4-methylphe- nylundecylketoxime, nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole, with or without additional ligands.

2.6. Oxamides, for example 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy- 5,5'-di-tert-butoxanilide, 2,2'-didodecyloxy-5,5'-di-tert-butoxanilide, 2-ethoxy-2'-ethyloxanilide, N,N'-bis(3-dimethylaminopropyl)oxamide, 2-ethoxy-5-tert-butyl-2'-ethoxanilide and its mixture with 2-ethoxy-2'-ethyl-5,4'-di-tert-butoxanilide, mixtures of o- and p-methoxy-disubstituted oxanilides and mixtures of o- and p-ethoxy-disubstituted oxanilides.

2.7. 2-(2-Hydroxyphenyl)-1 ,3,5-triazines, for example 2,4,6-tris(2-hydroxy-4-octyloxyphenyl)- 1 ,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1 ,3,5-triazine, 2- (2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1 ,3,5-triazine, 2,4-bis(2-hydroxy-4-propyl- oxyphenyl)-6-(2,4-dimethylphenyl)-1 ,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(4- methylphenyl)-1 ,3,5-triazine, 2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)- 1 ,3,5-triazine, 2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1 ,3,5-triazine, 2- [2-hydroxy-4-(2-hydroxy-3-butyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl)-1 ,3,5-triazine, 2-[2- hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1 ,3,5-triazine, 2-[4- (dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)- 1 ,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethyl- phenyl)-1 ,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1 ,3,5-triazine, 2-(2-hydr- oxy-4-methoxyphenyl)-4,6-diphenyl-1 ,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3-butoxy-2- hydroxypropoxy)phenyl]-1 ,3,5-triazine, 2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl- 1 ,3,5-triazine, 2-{2-hydroxy-4-[3-(2-ethylhexyl-1-oxy)-2-hydroxypropyloxy]phenyl}-4,6-bis(2,4- dimethylphenyl)-1 ,3,5-triazine, 2,4-bis(4-[2-ethylhexyloxy]-2-hydroxyphenyl)-6-(4- methoxyphenyl)-1 ,3,5-triazine.

2.8. Quinoline derivatives such as e.g. the commercially available UVINUL^® S-Pack.

3. Metal deactivators, for example N,N'-diphenyloxamide, N-salicylal-N'-salicyloyl hydrazine, N,N'-bis(salicyloyl)hydrazine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine, 3-salicyloylamino-1 ,2,4-triazole, bis(benzylidene)oxalyl dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl bisphenylhydrazide, N,N'-diacetyladipoyl dihydrazide, N,N'-bis(salicyl- oyl)oxalyl dihydrazide, N,N'-bis(salicyloyl)thiopropionyl dihydrazide. 4. Phosphites and phosphonites, for example triphenyl phosphite, diphenylalkyl phosphites, phenyldialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(2,4-di- cumylphenyl)pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, diisodecyloxypentaerythritol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)- pentaerythritol diphosphite, bis(2,4,6-tris(tert-butylphenyl)pentaerythritol diphosphite, tristea- ryl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphonite, 6- isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz[d,g]-1 ,3,2-dioxaphosphocin, bis(2,4-di-tert- butyl-6-methylphenyl)methyl phosphite, bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1 ,3,2-dioxaphosphocin, 2,2',2"-nitrilo- [triethyltris(3,3',5,5'-tetra-tert-butyl-1 ,1 '-biphenyl-2,2'-diyl)phosphite], 2-ethylhexyl(3,3',5,5'-te- tra-tert-butyl-1 ,1 '-biphenyl-2,2'-diyl)phosphite, 5-butyl-5-ethyl-2-(2,4,6-tri-tert-butylphenoxy)- 1 ,3,2-dioxaphosphirane.

The following phosphites are especially preferred:

Tris(2,4-di-tert-butylphenyl) phosphite (lrgafos^®168, Ciba Specialty Chemicals Inc.), tris(no- nylphenyl) phosphite,

5. Hydroxylamines, for example N,N-dibenzylhydroxylamine, N,N-diethylhydroxylamine, N, N- dioctylhydroxylamine, N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine, N, N- dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine, N-hexadecyl-N-octadecylhydrox- ylamine, N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derived from hydrogenated tallow amine.

6. Nitrones, for example, N-benzyl-alpha-phenylnitrone, N-ethyl-alpha-methylnitrone, N-octyl- alpha-heptylnitrone, N-lauryl-alpha-undecylnitrone, N-tetradecyl-alpha-tridecylnnitrone, N- hexadecyl-alpha-pentadecylnitrone, N-octadecyl-alpha-heptadecylnitrone, N-hexadecyl-al- pha-heptadecylnitrone, N-ocatadecyl-alpha-pentadecylnitrone, N-heptadecyl-alpha-hepta- decylnitrone, N-octadecyl-alpha-hexadecylnitrone, nitrone derived from N,N-dialkylhydroxyl- amine derived from hydrogenated tallow amine.

7. Thiosynergists, for example dilauryl thiodipropionate, dimistryl thiodipropionate, distearyl thiodipropionate or distearyl disulfide.

8. Peroxide scavengers, for example esters of β-thiodipropionic acid, for example the lauryl, stearyl, myristyl or tridecyl esters, mercaptobenzimidazole or the zinc salt of 2-mercapto- benzimidazole, zinc dibutyldithiocarbamate, dioctadecyl disulfide, pentaerythritol tetrakis(β- dodecylmercapto)propionate.

9. Polvamide stabilizers, for example copper salts in combination with iodides and/or phos- phorus compounds and salts of divalent manganese.

10. Basic co-stabilizers, for example melamine, polyvinylpyrrolidone, dicyandiamide, triallyl cyanurate, urea derivatives, hydrazine derivatives, amines, polyamides, polyurethanes, alkali metal salts and alkaline earth metal salts of higher fatty acids, for example calcium stearate, zinc stearate, magnesium behenate, magnesium stearate, sodium ricinoleate and potassium palmitate, antimony pyrocatecholate or zinc pyrocatecholate.

1 1. Nucleating agents, for example inorganic substances, such as talcum, metal oxides, such as titanium dioxide or magnesium oxide, phosphates, carbonates or sulfates of, preferably, alkaline earth metals; organic compounds, such as mono- or polycarboxylic acids and the salts thereof, e.g. 4-tert-butylbenzoic acid, adipic acid, diphenylacetic acid, sodium succinate or sodium benzoate; polymeric compounds, such as ionic copolymers (ionomers). Especially preferred are 1 ,3:2,4-bis(3',4'-dimethylbenzylidene)sorbitol, 1 ,3:2,4-di(paramethyl- dibenzylidene)sorbitol, and 1 ,3:2,4-di(benzylidene)sorbitol.

12. Fillers and reinforcing agents, for example calcium carbonate, silicates, glass fibres, glass beads, asbestos, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black, graphite, wood flour and flours or fibers of other natural products, synthetic fibers. 13. Other additives, for example plasticisers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow-control agents, flameproofing agents, antistatic agents and blowing agents.

14. Benzofuranones and indolinones, for example those disclosed in U.S. 4,325,863; U.S. 4,338,244; U.S. 5,175,312; U.S. 5,216,052; U.S. 5,252,643; DE-A-431661 1 ; DE-A-4316622; DE-A-4316876; EP-A-0589839, EP-A-0591102; EP-A-1291384 or 3-[4-(2- acetoxyethoxy)phenyl]-5,7-di-tert-butylbenzofuran-2-one, 5,7-di-tert-butyl-3-[4-(2-stearoyloxy- ethoxy)phenyl]benzofuran-2-one, 3,3'-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)ben- zofuran-2-one], 5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one, 3-(4-acetoxy-3,5-di- methylphenyl)-5,7-di-tert-butylbenzofuran-2-one, 3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di- tert-butylbenzofuran-2-one, 3-(3,4-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one, 3-(2,3- dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one, 3-(2-acetyl-5-isooctylphenyl)-5-isooctyl- benzofuran-2-one.

In general, the conventional additive may be present in the optical film of the present invention in an amount of, for example, 0.001 to 20 % or 0.01 to 20 %, preferably 0.001 to 5 % or 0.01 to 5 %, relative to the weight of Component (A).

Of interest is an optical film containing one or more further components selected from the group consisting of

(D) a benzotriazole UV absorber, preferably one of those listed above under item 2.1.

(E) a phenolic antioxidant, preferably one of those listed above under item 1.

(F) a pigment, preferably TiO₂, (G) a filler, for example one of those listed above under item 12; in particular TiO₂, and

(H) an optical brightener, for example 2,5-thiophenediyl bis(5-tert-butyl-1 ,3-benzoxazole) or 2,2'-(vinylene di-p-phenylene)bis(benzoxazole).

A particularly preferred benzotriazole UV absorber has the following structure:

This compound is commercially available as TINUVIN^®360.

In the optical film according to the present invention Component (B) is present in an amount of e.g. 0.05 to 10%, preferably 0.5 to 2%, relative to the weight of component (A).

Component (C) is optionally present in an amount of preferably 0.01 to 5%, in particular 0.1 to 0.5%, relative to the weight of component (A).

Component (D) is optionally present in an amount of preferably 0.05 to 10%, in particular 0.5 to 2%, relative to the weight of component (A).

Component (E) is optionally present in an amount of preferably 0.01 to 1 %, in particular 0.01 to 0.5%, relative to the weight of component (A).

Component (F) is optionally present in an amount of preferably 0.01 to 10%, relative to the weight of component (A). Component (G) is optionally present in an amount of preferably 1 to 70%, in particular 1 to

50%, e.g. 1 to 20%, relative to the weight of component (A).

Component (H) is optionally present in an amount of preferably 0.0001 to 10%, relative to the weight of component (A).

The weight ratio of the two different compounds selected from the group consisting of the compounds of the formulae (B-I) and (B-Il) is for example 1 :20 to 20:1 , preferably 1 :10 to 10:1 or 1 :5 to 5:1 , in particular 1 :3 to 3:1 or 1 :2 to 2:1 or 1 :1.

The optical film (or plaque) according to the present invention has for example a thickness of 10 to 2 000 μm, in particular 50 to 200 μm.

The optical film according to the present invention has excellent optical properties such as optical transparency, mechanical strength high enough to prevent e.g. contraction of a polarizer with high contractability, thermal resistance which can endure the high temperature which is applied during processes, and the like. The optical film according to the present invention has preferably a light transmittance at a wavelength of 280-380 nm of less than 5 %.

In the optical film according to the present invention, the amount of volatilization of component (B), when maintained at 300⁰C, is preferably less than 2 % by weight, in particular less than 1 % by weight.

The optical film according to the present invention preferably has a low haze value of e.g. less than 1 (determined at a 20 μm film) according to ASTM D 1003.

If desired, the optical film may be mono or biaxially oriented.

The optical films according to the present invention can be prepared by conventional methods which are well known to those skilled in the art; for example solution casting methods, melt molding methods such as melt extrusion molding, press molding or injection molding, or the like.

The method of incorporating present Component (B) and optionally futher additives into the optical film is not particularly limited and well known to those skilled in the art. There may be mentioned, for example, the incorporation of the compounds of the formulae (B-I) and (B-Il) into the thermoplastic resin or the use of a masterbatch of the compounds of the formulae (B-I-) and (B-Il) for the incorporation into the resin. It is for example possible to supply the compounds of the formulae (B-I) and (B-Il) during the melt extrusion molding; and the like, and any of these methods may be employed.

If desired, the optical film according to the present invention may be subjected to a corona treatment of the surface. This is adavantageous for improving the mutual adhesiveness; particularly, in the case of providing a surface treatment such as coating processing to the film surface, or in the case of laminating another film by using an adhesive.

A further preferred embodiment of the present invention is an optical film having a coating layer of e.g. 0.1 to 10 μm, in particular 1 to 5 μm, on one or both sides. The coating layer may contain for example an organic resin, an organic-silicone composite resin or a silicone-based material.

Examples of the aforementioned organic resin are melamine resins, acrylic resins, urethane resins, alkyd resins and fluorine-containing resins.

Examples of the aforementioned organic-silicone composite resin are a product formed by incorporating a partial hydrolysate of alkyltrialkoxysilane or tetraalkoxysilane to a polyester polyol or an etherified methylol melamine, and the like.

Examples of the aforementioned silicone-based material include a partial hydrolysate of aminosilane or epoxysilane, a partial hydrolysate of a silane coupling agent and alkyltrialkoxysilane tetraalkoxysilane, a hydrolysate of colloidal silica and alkyltrialkoxysilane, and the like.

If desired, the coating layer may contain various fillers. For example: in the case of forming a transparent conductive layer on the retardation and protection films of a liquid crystal display (LCD) and then using it as an electrode film for resistive overlay touch panels, the generation of a Newton ring caused by light interference between the transparent electrodes, or the blocking between the transparent conductive substrates can be prevented by adding suitable fillers.

Examples of fillers are organic fillers based on polymethacrylic acid ester, polyacrylic acid ester, polyolefin, polystyrene, divinylbenzene, benzoguanamine or organic silicone and inorganic fillers based on silica, alumina or titanium oxide.

A further embodiment of the present invention is a flat panel display containing an optical film as defined herein. The flat panel display is preferably a liquid crystal display or a plasma display. Such displays are well known to those skilled in the art. They are used for example in flat screen TV's, personal computers (note books and desk tops), mobile phones, personal digital assistants (PALM), video cameras, car navigation systems and games.

A typical LCD panel contains the following layers: Coating Layer Protection Film

Polarizing Film

Protection Film

Retardation Film (can be combined with the Protection Film) Color Filter

Retardation Film (can be combined with the Protection Film)

Protection Film

Polarizing Film

Protection Film DBEF (Dual brightness Enhancement Film)

BEF (brightness Enhancement RIm)

Prism Sheet

Diffuser Film

Diffuser Plate (multi-layered) CCFL (Cold Cathode Flourescent Light) or LED (Light Emitting Diode)

Reflection Film

A preferred embodiment of the present invention relates to a flat panel display which is a liquid crystal display wherein at least one film selected from the group consisting of the reflection film, the diffuser plate, the retardation and protection film is an optical film as defined herein.

The reflection film may contain for example one or more additives selected from the group consisting of pigments, fillers, optical brighteners, antistatic agents, nucleating agents, dispersants and slipping agent. Organic particles of polyolefins (e.g. polyethylene, polypropylene, polymethyl pentene, polybutane, cyclic olefin polymers), polystyrene, acrylics, polyesters, fluoro polymers or styrenic polymers, and inorganic particles of CaCO₃, ZnCO₃, TiO₂, ZnS, Sb₂O₃, MgO, silica, mica, talk, kaolin or BaSO₄ are particularly preferred.

The diffuser plate may contain for example one or more additives selected from the group consisting of glass, SiO₂, AI₂(OH)₃, CaCO₃, BaSO₄, TiO₂, styrenics, acrylics and siloxanes. The retardation and protection film may contain for example one or more additives selected from the group consisting of frame retardants, dispersants, lubricant, antioxidants, metal deactivators, SiC, TiO₂, SnO₂, BeO, SnO₂ and AI₂O₃.

Another embodiment of the present invention is the use of component (B) as defined above for improving the UV resistance of at least one optical film being present in a flat panel display.

Still another embodiment of the present invention is a composition containing the components (A), (B) and optionally (C) as defined above. All preferences indicated above for the optical film can be applied in appropriate manner to the composition.

The examples below illustrate the invention in greater detail. All percentages and parts are by weight, unless stated otherwise.

ADDITIVES TESTED:

Additive (B-l-a):

Additive (B-l-c): (TINUVI N^®1577)

Additive (B-ll-b): (TINUVIN^®460)

Additive (B-ll-c):

(TINUVIN^®477)

Additive (C-ll-a):

(CHIMASS0RB^®1 19)

DETERMINATION OF SYNERGISM: The synergistic effect of two coadditivs ((α) and (β)) is determined by a comparison of the calculated Yl (Yellowness Index) with the actually measured Yl. The Yl values are calculated on the basis of the additivity law (B. Ranby and J. F. Rabek; Photodegradation, Photo- oxidation and Photostabilization of Polymers, Principles and Applications, John Wiley & Sons, London, New York, Sydney, Toronto, 1975, pages 418 and 419) according to the following equation:

Expected stabilizing activity = Stabilizing activity of 100 % (α) + stabilizing activity of 100 % (β)

There is a synergistic effect for the two coadditivs in question, when Yl _measured^<YI calculated

Example 1 : Stabilization of injection molded styrene/methyl methacrylate copolymer plaques. Commercial styrene/methyl methacrylate copolymer (Estyrene^®MS 200, manufactured by Nippon Steel Chemical Co., Ltd.,) is mixed with the additives indicated in Table 1 in an inner mixer and compounded at 220⁰C with a twin-screw extruder. 2 mm plates of the compounded materials are prepared by an injection molding machine (barrel temperature: 220⁰C; mold temperature: 50°C.

Accelerated weathering is performed using an Atlas Ci65A Weather-O-meter, operated in dry mode (ASTM G 26 C).

After regular intervals, the yellowness indices (Yl) according to DIN 6167 are determined by means of a Spectraflash^®SF 600 Plus. The results are listed in Tables 1 and 2.

Table 1 :

Yl of 2 mm styrene/methyl methacrylate copolymer plaques after weathering.

Low values are desired.

Table 2:

Yl of 2 mm styrene/methyl methacrylate copolymer plaques after weathering.

Example 2: Stabilization of cyclic olefin polymer films.

10 g of commercial cyclic olefin polymer (Zeonex^®480 R, manufactured by Nippon Zeon Co., Ltd.,) are solved in 40 g of a mixture of chloroform (70%), cyclohexane (20%) and toluene (10%) with the additives indicated in Table 3 at room temperature. Then, 5 g of the solution are poured on a crystal plate and the solution is equally spread on the crystal plate by Erichen^®casting machine at room temperature. After 10 min evaporation of the solvent, a 20 micron solution cast film is obtained.

After regular intervals, the yellowness indices (Yl) according to DIN 6167 are determined by means of a Spectraflash^®SF 600 Plus. The results are listed in Table 3.

Table 3:

Yl of 20 micron cyclic olefin polymer films after weathering.

Low values are desired. Example 3: Stabilization of poly (methylmethacrylate).

10 g of a cyclic olefin polymer (Plaxiglas^® 7 N, manufactured by Evonik) are solved in 40 g of dichloromethane with the additives indicated in Table 4 at room temperature. Then, 5 g of the solution are poured on a crystal plate and the solution is equally spread on the crystal plate by an Erichen^®casting machine at room temperature. After 10 min evaporation of the solvent, a 20 micron solution cast film is obtained.

After regular intervals, the yellowness indices (Yl) according to DIN 6167 are determined by means of a Spectraflash^®SF 600 Plus. The results are listed in Table 4.

Table 4:

Yl of 20 micron poly (methylmethacrylate) films after weathering.

Low values are desired.

Example 4: Stabilization of an extrusion film sample of polycarbonate. Grinded commercial polycarbonate (Makrolon^®3108 FBL, manufactured by Bayer Material Science) is dried in a vacuum drier (Vacutherm 1400) for 6 hours at 120⁰C and mixed with the compounds indicated in Table 5 in an inner mixer (MTI / M20 FU) at 80⁰C. The mixture is compounded at 280⁰C with a twin-screw extruder (Berstorff ZE 25x32D). After drying for 6 hours at 120°C, the composition is processed at 280°C with a twin-screw extruder (Berstorff ZE 25x32D) again. After further drying of the composition for 6 hours at 120⁰C, a 0.1 mm film is obtained by means of an extruder (CoIMn CR-136 / 350) at 280°C. Accelerated weathering is performed using an Atlas Ci65A Weather-O-meter, operated in wet mode (ASTM G 26 A).

Initial and after 257 h, the yellowness indeces (Yl) are measured with a Spectraflash SF 600 Plus according to DIN 6167.

The results are listed in Table 5.

Table 5:

Yl of 0.1 mm polycarbonate films after weathering.

Low values are desired.

Claims

Claims:

1. An optical film for a flat panel display comprising the components

(A) a thermoplastic polymer;

(B) a mixture containing two or more different compounds selected from the group consisting of the compounds of the formulae (B-I) and (B-Il);

wherein E₁ is hydrogen, Ci-Ci₈alkyl, d-Ci₈alkyl substituted by 1 , 2 or 3 radicals selected from the group consisting of -OH, C₂-Ci8alkenyloxy, -C(O)OXi and -OC(O )X₂ with X₁ and X₂ being independently d-Ci₈alkyl; C₃-C₅₀alkyl interrupted by oxygen or C₃-C₅₀hydroxyalkyl interrupted by oxygen; E₂, E₃, E₄ and E₅ are independently hydrogen, CrCi₈alkyl, phenyl or phenyl substituted by 1 , 2 or 3 Ci-C₄alkyl;

wherein A₁, A₂, A₃ and A₄ are independently hydrogen, CrC₁₈alkyl, CrC₁₈alkyl substituted by

1 , 2 or 3 radicals selected from the group consisting of -OH, C₂-C₁₈alkenyloxy, -C(O)OY₁ and

-OC(O)Y₂ with Y₁ and Y₂ being independently CrC₁₈alkyl; C₃-C₅oalkyl interrupted by oxygen or C₃-C₅₀hydroxyalkyl interrupted by oxygen; and optionally

(C) at least one 2,2,6,6-tetramethylpiperidine derivative.

2. An optical film according to claim 1 wherein component (A) is a polystyrene, a styrene copolymer, a cyclic olefin homopolymer, a cyclic olefin copolymer, a polyester or a polycarbonate.

3. An optical film according to claim 1 wherein component (A) is a styrene/methyl methacrylate copolymer, a poly(methyl methacrylate) or a cyclic olefin polymer.

4. An optical film according to claim 1 wherein component (B) is a mixture of a compound of the formula (B-I) and a compound of the formula (B-Il).

5. An optical film according to claim 1 wherein the compound of the formula (B-I) is a compound of the formula (B-l-a), (B-l-b), (B-1-c), (B-l-d), (B-l-e) or (B-l-f) and the compound of the formula (B-Il) is a compound of the formula (B-ll-a), (B-ll-b) or (B-ll-c).

(B-l-e)

6. An optical film according to claim 1 , wherein component (B) is a mixture of the compounds (B-l-a) and (B-ll-b) or a mixture of the compounds (B-l-c) and (B-ll-c).

7. An optical film according to claim 1 , wherein component (C) is a compound of the formula (C-l-a), (C-l-b), (C-I-C), (C-l-d) (C-Il), (C-III) or (C-IV)

(C-l-b)

wherein bi is a number from 2 to 20 and the radicals Ri are independently hydrogen, Ci-C₈alkyl, O-, -OH, -CH₂CN, d-Ci₈alkoxy, C₅-Ci₂cycloalkoxy, C₃-C₆alkenyl, C₇-C₉phenylalkyl unsubstituted or substituted on the phenyl by 1 , 2 or 3 Ci-C₄alkyl; or

wherein the radicals R₂ have independently one of the meanings of Ri

wherein R₄ is hydrogen or Ci-C₄alkyl, R₅ is a direct bond or Ci-Cioalkylene, and b₃ is a number from 2 to 20.

8. An optical film according to claim 1 , containing the components (A), (B) and (C).

9. An optical film according to claim 1 , containing one or more further components selected from the group consisting of

(D) a benzotriazole UV absorber,

(E) a phenolic antioxidant,

(F) a pigment, and

(G) a filler.

10. An optical film according to claim 1 , which has a thickness of 10 to 2 000 μm.

11. A flat panel display which contains an optical film as defined in claim 1.

12. A flat panel display according to claim 1 , which is a liquid crystal display (LCD) or a plasma display.

13. A flat panel display according to claim 1 , which is a liquid crystal display wherein at least one film selected from the group consisting of the reflection film, the diffusion film, the retardation and protection film and the front film is an optical film as defined in claim 1.

14. The use of component (B) as defined in claim 1 for improving the UV resistance of at least one optical film being present in a flat panel display.

15. A composition containing the components (A), (B) and optionally (C) as defined in claim 1.