Piperazinone derivatives

0001Piperazinone derivatives

0002This invention relates to piperazinone derivatives, to an organic material susceptible to light , heat or oxidation, containing a piperazinone derivative and to a method for stabilizing such an organic material. This invention further relates to intermediate products.

0003Several piperazinone derivatives and their use as stabilizers are described in US-A-4,629,752 and US-A-4,480,092.

0004The present invention relates in particular to a compound of the formula (I)

0005<img file="WO0031069A1_D0001.tif" /> wherein at least one group of the formula (II)

0006<img file="WO0031069A1_D0002.tif" /> is present in the repeating unit of the formula (I); n is a number from 1 to 100; G₂, G₃ and G₄ are independently of one another d-Cjealkyl or C₅-C₁₂cycloalkyl or the radicals Gs and G₂ and the radicals G₃ and G form independently of one another, together with the carbon atom they are attached to, C₅-C₁₂cycloalkyl;

0007R_T is hydrogen, C_rC₁₈alkyl, oxyl, -OH, -CH₂CN, C₃-C₆alkenyl, C₃-C₈alkynyl,

0008C₇-C₁₂phenylalkyl unsubstituted or substituted on the phenyl by 1 , 2 or 3 C₁-C₄alkyi or

0009C C alkoxy; C C₈acyl, C C₁₈alkoxy, C₅-C₁₂cycloalkoxy, C₇-C₁₂phenylalkoxy unsubstituted or substituted on the phenyl by 1 , 2 or 3 Cj-C alkyl or Cj-Ctalkoxy; C_rCi₈alkanoyloxy, <img file="WO0031069A1_D0003.tif" /> glycidyl or a group -CH₂CH(OH)(G) with G being hydrogen, methyl or phenyl;

0010R₂ is C₂-C₁₄alkylene or a group -CR₂'(R₂")- with R₂' and R₂" being independently of one another hydrogen, <img file="WO0031069A1_D0004.tif" /> or C₅-Cι₂cycloalkyl;

0011R₃' and R₃" are independently of one another hydrogen, Cι-C₁₈al yl, C₂-C₁₈alkyl interrupted by oxygen; or C₅-C₁₂cycloalkyl;

0012R₄ is C -C₁₄alkylene, C₄-C₁₄alkylene interrupted by oxygen or sulphur; C₅-C₇cycloalkylene,

0013C₅-C₇cycloalkylenedi(C₁-C alkylene), C₁-C₄alkylenedi(C₅-C₇cycloalkylene) or phenylenedi-

0014(CrC alkylene);

0015R₅' and R₅" are independently of one another hydrogen, Cι-C₁₈alkyl, C₃-C₁₈alkenyl,

0016C₅-Cι₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 C C alkyl;

0017C₇-C₁₂phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 C C alkyl; tetrahydrofurfuryl, a group of the formula (II) or C₂-C₄alkyl which is substituted in the 2, 3 or 4 position by -OH, CrC₈alkoxy, di(C₁-C alkyl)amino or a group of the formula (III);

0018N - (Ml)

0019\

0020with E being a direct bond, -0-, -CH₂-, -CH₂CH₂- or >N-CH₃; X is -OR₆, -SR₆, -N(R₇)(R₈) or a group of the formula (IV);

0021<img file="WO0031069A1_D0005.tif" />

0022R₆, R₇ and R₈ are independently of one another hydrogen, Cj-Cjβalkyl, C₃-C₁₈alkenyl, C₅-C₁₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 C C₄alkyl; phenyl which is unsubstituted or substituted by 1 , 2 or 3 C C alkyl or C C₄alkoxy; C₇-C₁₂phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 C C₄alkyl; tetrahydrofurfuryl or C₂-C₄alkyl which is substituted in the 2, 3 or 4 position by CrC₈alkoxy, di(C_rC₄alkyl)amino or a group of the formula (III); or -N(R₇)(R₈) is additionally a group of the formula (III);

0023T is -O- or >N-R₉; and

0024R₉ is hydrogen, C C₁₈alkyl, C₂-C₁₈hydroxyalkyl, C₃-C₁₈alkenyl, C₅-C₁₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 d-C₄alkyl; C₇-C₁₂phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 C C₄alkyl; tetrahydrofurfuryl, a group of the formula (II), or C₂-C₄alkyl which is substituted in the 2, 3 or 4 position by CrC₈alkoxy, di(C C₄alkyl)amino or a group of the formula (III); the radicals R_{1 f} the radicals R₂, the radicals R₃', the radicals R₃", the radicals G^ the radicals G₂, the radicals G₃ or the radicals G , independently of one another, have the same or a different meaning; and in the individual recurrent units of the formula (I), each of the radicals X, R₄, R₅' and R₅" has the same or a different meaning; with the proviso that one of the radicals R₅' and R₅" is different from hydrogen, when

0025X is a group of the formula (IV) with T being >N-R₉.

0026Examples of alkyl containing not more than 18 carbon atoms are methyl, ethyl, propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl, 2-pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, hexadecyl and octadecyl.

0027Gi, G₂, G₃ and G₄ are preferably d-dalkyl, in particular methyl.

0028One of the preferred meanings of R is CrC₄alkyl, in particular methyl.

0029One of the preferred meanings of R₃' and R₃" are C_rC₈alkyl, in particular d-dalkyl, for example methyl.

0030One of the preferred meanings of R₇, R₈ and R₉ is C C₈alkyl.

0031An example of C₂-C₁₈hydroxyalkyl and of C₂-C alkyl substituted by -OH is 2-hydroxyethyl.

0032Examples of C₂-C₁₈alkyl interrupted by oxygen and of C₂-C alkyl substituted by Cj-Cβalkoxy, preferably by C C₄alkoxy, in particular methoxy or ethoxy, are 2-methoxyethyl, 2-ethoxyethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-butoxypropyl, 3-octoxypropyl and 4-methoxybutyl.

0033Examples of C₂-C₄alkyl substituted by di(C₁-C₄alkyl)amino, preferably by dimethylamino or diethylamino, are 2-dimethylaminoethyl, 2-diethylaminoethyl, 3-dimethylaminopropyl, 3-diethyiaminopropyl, 3-dibutylaminopropyl and 4-diethylaminobutyl.

0034The group of the formula (III) is preferably — N O

0035Preferred examples of C₂-C alkyl substituted by a group of the formula (III) are groups of the

0036formula Y N (CH₂) . The group o N (CH₂) is particularly

0037preferred.

0038Examples of alkenyl containing not more than 18 carbon atoms are allyl, 2-methylallyl, butenyl, hexenyl, undecenyl and octadecenyl. Alkenyls in which the carbon atom in the 1 -position is saturated are preferred, and allyl is particularly preferred.

0039An example of C₃-C₈alkynyl is 2-butynyl.

0040Examples of alkoxy containing not more than 18 carbon atoms are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy, dodecyloxy, tetradecyloxy, hexadecyloxy and octadecyloxy. C₆-C₁₂Alkoxy, in particular heptoxy and octoxy, is one of the preferred meanings of Rj.

0041Examples of acyl (aliphatic, cycloaliphatic or aromatic) containing not more than 8 carbon atoms are formyl, acetyl, propionyl, butyryl, pentanoyl, hexanoyl, heptanoyl, octanoyl and benzoyl. d-C₈Alkanoyl and benzoyl are preferred. Acetyl is especially preferred.

0042Examples of C_rC₁₈alkanoyloxy are formyloxy, acetyloxy, propionyloxy, butyryloxy, pentanoyloxy, hexanoyloxy, heptanoyloxy and octanoyloxy.

0043Examples of (d-C₁₈alkoxy)carbonyl are methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl, heptyloxycarbonyl and octyloxycarbonyl. Examples of C₅-d₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 C C alkyl are cyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, trimethylcyclohexyl, t-butylcyclohexyl, cyclooctyl, cyclodecyl and cyclododecyl. Unsubstituted or substituted C₅-C₈cycloalkyl, in particular cyclohexyl, is preferred.

0044Examples of C₅-d₂cycloalkoxy are cyclopentoxy, cyclohexoxy, cycloheptoxy, cyclooctoxy, cyclodecyloxy, cyclododecyloxy and methylcyclohexoxy. C₅-C₈Cycloalkoxy, in particular cyclopentoxy and cyclohexoxy, is preferred.

0045Examples of phenyl substituted by 1 , 2 or 3 C C₄alkyl or C_rC₄alkoxy are methylphenyl, dimethylphenyl, trimethylphenyl, t-butylphenyl, di-t-butylphenyl, 3,5-di-t-butyl-4-methylphenyl, methoxyphenyl, ethoxyphenyl and butoxyphenyl.

0046Examples of C₇-C₁₂phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 Cι-C alkyl or C C₄alkoxy are benzyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl, t-butylbenzyl, 2-phenylethyl and methoxybenzyl. C₇-C₉phenylalkyl, in particular benzyl, is preferred.

0047Example of C₇-C₁₂phenylalkoxy unsubstituted or substituted on the phenyl by 1 , 2 or 3 Cι-C alkyl or C C alkoxy are benzyloxy, methylbenzyloxy, dimethylbenzyloxy, thmethylbenzyloxy, t-butylbenzyloxy, 2-phenylethyloxy and methoxybenzyloxy. C₇-C₉phenylalkoxyi, in particular benzyloxy, is preferred.

0048Examples of alkylene containing not more than 14 carbon atoms are ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, octamethylene, decamethylene and dodecamethylene. R₄ is for example C₂-C₈alkylene, preferably hexamethylene.

0049R₂ as a group -CR '(R₂")- is preferably methylene.

0050Examples of C₄-Cι₄alkylene interrupted by -O- or -S-, e.g. 1 , 2 or 3 -O- or -S-, are 3-oxapentane-1 ,5-diyl, 4-oxaheptane-1 ,7-diyl, 3,6-dioxaoctane-1 ,8-diyl, 4,7-dioxadecane- 1 ,10-diyl, 4,9-dioxadodecane-1 ,12-diyl, 3,6,9-trioxaundecane-1 ,1 1-diyl, 4,7,10-trioxatridecane-1 ,13-diyl, 3-thiapentane-1 ,5-diyl, 4-thiaheptane-1 ,7-diyl, 3,6-dithiaoctane-1 ,8-diyl, 4,7-dithiadecane-1 ,10-diyl, 4,9-dithiadodecane-1 ,12-diyl, 3,6,9-trithiaundecane-1 ,11-diyl and 4,7,10-trithiatridecane-1 ,13-diyl.

0051An example of C₅-C₇cycloalkylene is cyclohexylene.

0052An example of C₅-C₇cycloalkylenedi(C_rC₄alkylene) is cyclohexylenedimethylene.

0053Examples of d-C alkylenedi(C₅-C₇cycloalkylene) are methylenedicyclohexylene and isopropylidenedicyclohexylene.

0054An example of phenylenedi(d-C₄alkylene) is phenylenedimethylene.

0055n is for example a number from 1 to 100, 2 to 100, 3 to 100, 4 to 100, 5 to 100, 6 to 100, 1 to 50, 2 to 50, 3 to 50, 4 to 50, 5 to 50, 6 to 50, 1 to 30, 2 to 30, 3 to 30, 4 to 30, 5 to 30, 6 to 30, 1 to 20, 2 to 20, 3 to 20, 4 to 20, 5 to 20 or 6 to 20. n as a number from 2 to 50, in particular 3 to 7, is preferred.

0056R₅' and R₅" are preferably a group of the formula (II).

0057R₃' is preferably hydrogen.

0058R₂ is preferably methylene.

0059X is preferably a group -N(R₇)(R₈), in particular -NH(R₈).

0060Rj is preferably hydrogen, C C₄alkyl, -OH, allyl, C_rCι₂alkoxy, C₅-C₈cycloalkoxy, benzyl or acetyl, in particular hydrogen or C C₄alkyl such as methyl.

0061Preferred compounds of the formula (I) are those wherein

0062G₁₅ G₂, G₃ and G₄ are independently of one another C C₆alkyl or cyclohexyl or the radicals Gj and G₂ and the radicals G₃ and G₄ form independently of one another, together with the carbon atom they are attached to, cyclohexyl; R₂ is C₂-C₈alkylene or a group -CR₂'(R₂")- with R₂' and R₂" being independently of one another hydrogen, d-C₈alkyl or C₅-C₈cycloalkyl;

0063R₃' and R₃" are independently of one another hydrogen, d-C₈alkyl, C₂-C₈alkyl interrupted by oxygen; or C₅-C₈cycloalkyl;

0064R₄ is C₂-C₁₀alkylene, C₄-Cι₀alkylene interrupted by oxygen or sulphur; cyclohexylene, cyclohexylenedi(d-C alkylene), C₁-C alkylenedi(cyclohexylene) or phenylenedi(d-dalkylene);

0065R₅' and R₅" are independently of one another hydrogen, C_rC₈alkyl, C₃-C₁₂alkenyl,

0066C₅-C₈cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 C C alkyl;

0067C₇-C₉phenylalkyl; tetrahydrofurfuryl, a group of the formula (II) or C -C₄alkyl which is substituted in the 2, 3 or 4 position by -OH, C_rC alkoxy, di(Cι-C₄alkyl)amino or a group of the formula (III);

0068R₆, R₇ and R₈ are independently of one another hydrogen, d-C₈alkyl, C₃-Cι₂alkenyl,

0069C₅-C₈cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 C C alkyl; phenyl which is unsubstituted or substituted by 1 , 2 or 3 d-C₄alkyl or C C alkoxy; C₇-C₁₂phenylalkyl; tetrahydrofurfuryl or C₂-C alkyl which is substituted in the 2, 3 or 4 position by C C alkoxy, di(Cι-C alkyl)amino or a group of the formula (III); or -N(R₇)(R₈) is additionally a group of the formula (III); and

0070R₉ is hydrogen, C_rC₈alkyl, C₂-C₈hydroxyalkyl, C₃-C₁₂alkenyl, C₅-C₈cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 d-C alkyl; C₇-C₁₂phenylalkyl; tetrahydrofurfuryl, a group of the formula (II), or C -C alkyl which is substituted in the 2, 3 or 4 position by d-C₄alkoxy, di(C₁-C alkyl)amino or a group of the formula (III).

0071Particularly preferred compounds of the formula (I) are those wherein

0072G- , G₂, G₃ and G₄ are independently of one another d-C₄alkyl;

0073R₂ is C₂-C₄alkylene or a group -CR₂'(R₂")- with R₂' and R₂" being independently of one another hydrogen or d-C₄alkyl;

0074R₃' and R₃" are independently of one another hydrogen or d-C alkyl;

0075R₄ is C₂-C₁₀alkylene;

0076R₅' and R₅" are independently of one another hydrogen, C C₄alkyl, C₃-C₈alkenyl, cyclohexyl, benzyl or a group of the formula (II);

0077X is -N(R₇)(R₈) or a group of the formula (IV);

0078R₇ and R₈ are independently of one another hydrogen or C_rC₈alkyl; or -N(R₇)(R₈) is additionally a group of the formula (III) with E being -O-; and R₉ is hydrogen, Cι-C₈alkyl or cyclohexyl.

0079Compounds of the formula (I) which are of particular interest are those wherein n is a number from 2 to 50;

0080G-i, G₂, G₃ and G₄ are independently of one another d-C₄alkyl;

0081R-i is hydrogen or d-C₄alkyl;

0082R₂ is methylene;

0083R₃' is hydrogen and R₃" is hydrogen or C₁-C₄alkyl;

0084R₄ is C₂-C₈alkylene;

0085R₅' and R₅" are a group of the formula (II); and

0086X is -N(R₇)(R₈) with R₇ and R₈ being independently of one another hydrogen or C C₈alkyl.

0087The definition of the terminal groups which saturate the free valences in the compounds of the formula (I) depends on the process used for their preparation. The terminal groups can also be modified after the preparation of these compounds.

0088The compounds of the formula (I) may be prepared, for example, by reacting a compound of the formula (Z-00)

0089Cl ^ Cl (Z-00)

0090X with a compound of the formula (Z-0)

0091<img file="WO0031069A1_D0006.tif" /> wherein X, R₄, R₅' and R₅" are as defined above. Either the compound of the formula (Z-00) or the compound of the formula (Z-0) can be used in an excess of up to 20 mol %, preferably 5 mol %. The molar ratio of the compounds of the formulae (Z-00) and (Z-0) is in particular 1 :1.1. According to a preferred procedure, the compound of the formula (Z-0) is used in an excess of up to 5 mol %. The reaction is preferably carried out in an inert organic solvent, for example toluene, xylene or benzene, in the presence of an inorganic base at a temperature of 40° to 145°C, in particular 60° to 140°C. Examples of a base are NaOH, KOH, Na₂CO₃ and K₂CO₃.

0092In this case, the terminal group bonded to the diamino radical may be hydrogen or a group

0093<img file="WO0031069A1_D0007.tif" /> and the terminal group bonded to the triazine radical may be Cl or a group

0094<img file="WO0031069A1_D0008.tif" />

0095When the terminal group is Cl, it is advantageous to replace it, for example, by a group -X as defined above, in particular -OH, an amino group -N(R₇)(R₈) or a group of the formula (IV), after the reaction is complete. Examples of suitable replacement groups are pyrrolidin-1-yl, morpholino, -NH₂, -N(d-C₈alkyl)₂ and -NR(d-C₈alkyl) with R being hydrogen or a group of the formula (II).

0096It is further advantageous to replace the terminal hydrogen of the group

0097<img file="WO0031069A1_D0009.tif" /> by C C₈acyl, (C_rC₈alkoxy)carbonyl, (C₅-C₁₂cycloalkoxy)carbonyl, (d-C₈alkyl)aminocarbonyl, (C₅-Cι₂cycloalkyl)aminocarbonyl,

0098(C₇-C₉phenylalkyl)aminocarbonyl, d-C₈alkyl, C₅-d₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 C_rC alkyl; C₃-C₆alkenyl, C₇-C₉phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 Cι-C₄alkyl; or -CH₂CN.

0099d-C₈acyl, preferably d-C₈alkanoyl, in particular acetyl as shown below in EXAMPLE 5 is preferred.

0100A preferred embodiment of this invention relates to compounds of the formula (I) wherein the terminal group attached to the diamino radical is hydrogen, C C₈acyl, (d-C₈alkoxy)carbonyl, (C₅-C₁₂cycloalkoxy)carbonyl, (d-C₈alkyl)aminocarbonyl, (C₅-C₁₂cycloalkyl)aminocarbonyl, (C₇-C₉phenylalkyl)aminocarbonyl, C C₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 d-C alkyl; C₃-C₆alkenyl, C₇-C₉phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 C_rC₄alkyl; or -CH₂CN, and the terminal group attached to the triazine residue is a group

0101<img file="WO0031069A1_D0010.tif" /> with R^* being hydrogen, d-C₈acyl, (d-C₈alkoxy)carbonyl,

0102(C₅-C₁₂cycloalkoxy)carbonyl, (d-C₈alkyl)aminocarbonyl, (C₅-C₁₂cycloalkyl)aminocarbonyl, (C₇-C₉phenylalkyl)aminocarbonyl, C C₈alkyl, C₅-C₁₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 d-dalkyl; C₃-C₆alkenyl, C₇-C₉phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 C_rC₄alkyl; or -CH₂CN.

0103A particularly preferred embodiment of this invention relates to compounds of the formula (I) wherein the terminal group attached to the diamino radical is d-C₈alkanoyl and the terminal group attached to the triazine residue is a group

0104-N- -(C C₈alkanoyl)

0105Compounds of the formula (Z-0) wherein R₅' is a group of the formula (II) correspond to the formula (Z-1 )

0106<img file="WO0031069A1_D0011.tif" />with Gi, G₂, G₃, G , R^ R₂, R₃', R₃", R and R₅" being as defined above,

0107and constitute a further embodiment of this invention.

0108When R₃' and/or R₃" are hydrogen, a compound of the formula (Z-1 ) wherein R₅" is optionally a group of the formula (II) can be prepared, for example, by reacting - in a stoichiometric ratio - a ketone of the formula (Z-2)

0109<img file="WO0031069A1_D0012.tif" /> with a diamine of the formula (Z-3)

0110H- — N— -R₄- — N H (Z-3)

I

I

0113H R_β wherein Gi, G , G₃, G₄, Ri, R₂, R₃" and R are as defined above and R₅ is hydrogen, d-C₁₈alkyl, C₃-C₁₈alkenyl, C₅-d₂cycloalkyl which is unsubstituted or substituted by 1 , 2 or 3 d-C alkyl; C₇-C₁₂phenylalkyl which is unsubstituted or substituted on the phenyl by 1 , 2 or 3 d-C alkyl; tetrahydrofurfuryl, or C₂-C₄alkyl which is substituted in the 2, 3 or 4 position by -OH, d-C₈alkoxy, di(d-C₄alkyl)amino or a group of the formula (III), and subsequent hydrogenation.

0114The reaction which is a reductive amination is conveniently carried out under a hydrogen pressure of 30 to 35 atm in the presence of a hydrogenation catalyst such as platinum on carbon, palladium or Raney nickel, in particular platinum on carbon, in neat or in an organic solvent, for example methanol or a mixture of isopropanol and water. The temperature is preferably 40° to 100°C.

0115When R₃' and R₃" are different from hydrogen, the compound of the formula (Z-1 ) may be prepared, for example, by adding an organometallic derivative of the formula R₃'-M with R₃' being C C₁₈alkyl, C₂-C₁₈alkyl interrupted by oxygen; or C₅-C₁₂cycloalkyl and M being Li⁺, MgCI⁺, Na⁺, K⁺ or Cu⁺, in particular Li\ to a solution of the corresponding ketimine in an inert organic solvent such as diethyl ether, tetrahydrofurane or xylene at low temperature, for example -78° - 0°C. The reaction may be carried out in analogy to the procedure described in "Advanced Organic Chemistry, Jerry March, John Wiley &amp; Sons, 4 th edition, pp 934-935" or in 'The chemistry of the carbon-nitrogen double bond, edited by S. Patai, John Wiley &amp; Sons, 1970, pp 266-272".

0116The ketone of the formula (Z-2) which constitute a further embodiment of this invention can be prepared, for example, by oxidation of a compound of the formula (Z-4)

0117<img file="WO0031069A1_D0013.tif" /> wherein Gi, G₂, G₃, G₄, Ri, R₂ and R₃" are as defined above. The reaction may be carried out analogously to the Swern oxidation (Fieser and Fieser's Reagents for Organic Synthesis, Volume 8, John Wiley &amp; Sons, 1980, page 200).

0118The compounds of the formula (Z-4) can be prepared, for example, in analogy to the method described in US-A-4, 167,512.

0119The compounds of the formula (I) as well as the intermediates of the formulae (Z-1) and (Z-2) are very effective in improving the light, heat and oxidation resistance of organic materials, especially synthetic polymers and copolymers.

0120Examples of organic materials which can be stabilized are: 1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, po- lybut-1-ene, poly-4-methylpent-1 -ene, 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).

0121Polyolefins, 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:

0122a) radical polymerisation (normally under high pressure and at elevated temperature).

0123b) catalytic polymerisation using a catalyst that normally contains one or more than one metal of groups IVb, Vb, Vlb 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 la, Ila 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).

01242. 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, propylene/butadiene copolymers, isobutylene/isoprene copolymers, ethy- lene/alkyl acrylate copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl acetate copolymers and their copolymers with carbon monoxide 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-norbomene; and mixtures of such copolymers with one another and with polymers mentioned in 1 ) above, for example polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random polyalkylene/carbon monoxide copolymers and mixtures thereof with other polymers, for example polyamides.

01254. Hydrocarbon resins (for example C₅-C₉) including hydrogenated modifications thereof (e.g. tackifiers) and mixtures of polyalkylenes and starch.

01265. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).

01276. Copolymers of styrene or α-methylstyrene with dienes or acrylic derivatives, for example styrene/butadiene, styrene/acrylonitrile, styrene/alkyl methacrylate, styrene/butadiene/alkyl acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic anhydride, styrene/acryloni- trile/methyl acrylate; mixtures of high impact strength of styrene copolymers and another polymer, for example a polyacrylate, a diene polymer or an ethylene/propylene/diene terpo- lymer; and block copolymers of styrene such as styrene/butadiene/styrene, styrene/iso- prene/styrene, styrene/ethylene/butylene/styrene or styrene/ethylene/propylene/ styrene.

01287. Graft copolymers of styrene or α-methylstyrene, for example styrene on polybutadiene, styrene on polybutadiene-styrene or polybutadiene-acrylonitrile copolymers; styrene and acrylonitrile (or methacrylonitrile) on polybutadiene; styrene, acrylonitrile and methyl methacrylate on polybutadiene; styrene and maleic anhydride on polybutadiene; styrene, acrylo^¬ nitrile and maleic anhydride or maleimide on polybutadiene; styrene and maleimide on poly- butadiene; 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 6), for example the copolymer mixtures known as ABS, MBS, ASA or AES polymers.

01298. Halogen-containing polymers such as polychloroprene, chlorinated rubbers, chlorinated and brominated copolymer of isobutylene-isoprene (halobutyl rubber), chlorinated or sulfo- chlorinated polyethylene, copolymers of ethylene and chlorinated ethylene, epichlorohydrin homo- and copolymers, especially polymers of halogen-containing vinyl compounds, for example polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, as well as copolymers thereof such as vinyl chloride/vinylidene chloride, vinyl chloride/vinyl acetate or vinylidene chloride/vinyl acetate copolymers.

01309. Polymers derived from α,β-unsaturated acids and derivatives thereof such as polyacry- lates and polymethacrylates; polymethyl methacrylates, polyacrylamides and polyacryloni- triles, impact-modified with butyl acrylate.

013110. Copolymers of the monomers mentioned under 9) with each other or with other unsaturated monomers, for example acrylonitrile/ butadiene copolymers, acrylonitrile/alkyl acrylate copolymers, acrylonithle/alkoxyalkyl acrylate or acrylonitrile/vinyl halide copolymers or acrylonitrile/ alkyl methacrylate/butadiene terpolymers.

013211. Polymers derived from unsaturated alcohols and amines or the acyl derivatives or ace- tals 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.

013312. Homopolymers and copolymers of cyclic ethers such as polyalkylene glycols, polyethylene oxide, polypropylene oxide or copolymers thereof with bisglycidyl ethers.

013413. Polyacetals such as polyoxymethylene and those polyoxymethyienes which contain ethylene oxide as a comonomer; polyacetals modified with thermoplastic polyurethanes, acrylates or MBS. 14. Polyphenylene oxides and sulfides, and mixtures of polyphenylene oxides with styrene polymers or polyamides.

013515. Polyurethanes derived from hydroxyl-terminated polyethers, polyesters or polybutadi- enes on the one hand and aliphatic or aromatic polyisocyanates on the other, as well as precursors thereof.

013616. Polyamides and copolyamides derived from diamines and dicarboxylic acids and/or from aminocarboxylic acids or the corresponding lactams, for example polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11 , polyamide 12, aromatic polyamides starting from m-xylene diamine and adipic acid; polyamides prepared from hexamethylenediamine and isophthalic or/and terephthalic acid and with or without an elastomer as modifier, for example poly-2,4,4,-thmethylhexamethylene terephthalamide or poly- m-phenylene isophthalamide; and also block copolymers of the aforementioned polyamides with polyolefins, olefin copolymers, ionomers or chemically bonded or grafted elastomers; or with polyethers, e.g. with polyethylene glycol, polypropylene glycol or polytetramethylene glycol; as well as polyamides or copolyamides modified with EPDM or ABS; and polyamides condensed during processing (RIM polyamide systems).

013717. Polyureas, polyimides, polyamide-imides, polyetherimids, polyesterimids, polyhydantoins and polybenzimidazoles.

013818. Polyesters derived from dicarboxylic acids and diols and/or from hydroxycarboxylic acids or the corresponding lactones, for example polyethylene terephthalate, polybutylene terephthalate, poly-1 ,4-dimethylolcyclohexane terephthalate and polyhydroxybenzoates, as well as block copolyether esters derived from hydroxyl-terminated polyethers; and also polyesters modified with polycarbonates or MBS.

013919. Polycarbonates and polyester carbonates.

014020. Polysulfones, polyether sulfones and polyether ketones. 21. Crosslinked polymers derived from aldehydes on the one hand and phenols, ureas and melamines on the other hand, such as phenol/formaldehyde resins, urea/formaldehyde resins and melamine/formaldehyde resins.

014122. Drying and non-drying alkyd resins.

014223. Unsaturated polyester resins derived from copolyesters of saturated and unsaturated dicarboxylic acids with polyhydric alcohols and vinyl compounds as crosslinking agents, and also halogen-containing modifications thereof of low flammability.

014324. Crosslinkable acrylic resins derived from substituted acrylates, for example epoxy acrylates, urethane acrylates or polyester acrylates.

014425. Alkyd resins, polyester resins and acrylate resins crosslinked with melamine resins, urea resins, isocyanates, isocyanurates, polyisocyanates or epoxy resins.

014526. Crosslinked epoxy resins derived from aliphatic, cycloaliphatic, heterocyclic or aromatic glycidyl compounds, e.g. products of diglycidyl ethers of bisphenol A and bisphenol F, which are crosslinked with customary hardeners such as anhydrides or amines, with or without accelerators.

014627. 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.

014728. Blends of the aforementioned polymers (polyblends), for example PP/EPDM, Poly- 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.

014829. Naturally occurring and synthetic organic materials which are pure monomeric compounds or mixtures of such compounds, for example mineral oils, animal and vegetable fats, oil and waxes, or oils, fats and waxes based on synthetic esters (e.g. phthalates, adipates, phosphates or trimellitates) and also mixtures of synthetic esters with mineral oils in any weight ratios, typically those used as spinning compositions, as well as aqueous emulsions of such materials.

014930. Aqueous emulsions of natural or synthetic rubber, e.g. natural latex or latices of carbo- xyiated styrene/butadiene copolymers.

0150This invention thus also relates to a composition comprising an organic material susceptible to degradation induced by light, heat or oxidation and at least one compound of the formula (I).

0151The organic material is preferably a synthetic polymer, more particularly one selected from the aforementioned groups.

0152A thermoplastic rubber (TPR) as an organic material is also of interest.

0153Polyolefins and their copolymers, for example those listed above under items 1-3, in particular polyethylene and polypropylene, are preferred.

0154Polycarbonate such as in item 19 above, and blends, such as in item 28 above, thermoplastic polyurethan (TPU) or polyacetal are also preferred.

0155Other materials which may be stabilized with the compounds of the formula (I) are recording materials for photographic reproduction and other reprographic techniques as described for example in Research Disclosure 1990, 31429 (pages 474-480), GB-A-2,319,523 or DE-A-19,750,906, page 22, line 15 to page 105, line 32.

0156Thus, a further embodiment of this invention is a recording material, in particular a photographic material, containing at least one compound of the formula (I). Of special importance is also the stabilization of non-silver reprographic materials, for example, those used for pressure-sensitive copying systems, microcapsule photocopier systems, heat-sensitive copier systems and ink-jet printing.

0157The recording materials stabilized with the compounds of the formula (I) have an unexpectedly high quality, especially in terms of their light stability.

0158The recording materials have a structure which is known per se and which corresponds to their utility. They consist of a base, for example a paper or plastic film, on which one or more coatings are applied. Depending on the type of the material, these coats contain the suitable components required. In the case of photographic materials, the coats contain for example silver halide emulsions, colour couplers, dyes and the like. The material intended for ink-jet printing has e.g. a customary base on which an absorption layer suitable for ink is located. Uncoated paper can likewise be employed for ink-jet printing. In the latter case, the paper simultaneously functions as a base and has the absorbent for the ink. Suitable materials for ink-jet printing are described, inter alia, in US-A-5,073,448, the disclosure content of which is regarded as part of the present description.

0159The recording material can also be transparent, for example in the case of projection films.

0160The compound of the formula (I) can be incorporated into the material even in the course of manufacture; in papermaking, for example, by addition to the pulp. Another method of use is the spraying of the material with an aqueous solution of the compound of the formula (I), or the addition thereof to the coating.

0161Coatings for transparent recording materials for projection must not contain any light-scattering particles such as pigments or fillers.

0162The colour-binding coatings can contain further additives, for example antioxidants, light stabilizers (including UV absorbers and/or conventional hindered amine light stabilizers), viscosity improvers, brighteners, biocides and/or antistats.

0163The coating is usually prepared as described in the following. The water-soluble components, for example the binder, are dissolved in water and mixed. The solid components, for example fillers and other additives as already described, are dispersed in this aqueous medium. Dispersion is advantageously brought about with the aid of equipment such as ultrasonic devices, turbine agitators, homogenizers, colloid mills, bead mills, sand mills, high-speed stirrers and the like. A particular advantage of the compounds of the formula (I) is that they can easily be incorporated into the coating.

0164As mentioned above, the recording materials cover a broad field of use. Compounds of the formula (I) can be employed, for example, in pressure-sensitive copier systems. They can be added to the paper to protect the micro-encapsulated dye precursors against light, or to the binder of the developer layer for protecting the dyes formed therein.

0165Photocopier systems with light-sensitive microcapsules which are developed by pressure are described, inter alia, in US-A-4,416,966, US-A-4,483,912, US-A-4,352,200, US-A-4,535,050, US-A-4,536,463, US-A-4,551 ,407, US-A-4,562,137 and US-A-4,608,330 and also in EP-A-139,479, EP-A-162,664, EP-A-164,931 , EP-A-237,024, EP-A-237,025 and EP-A-260,129. In all these systems, the compounds of the formula (I) can be added to the colour-accepting layer. Alternatively, the compounds of the formula (I) can be added to the donor layer for protecting the colour formers against light.

0166The compounds of the formula (I) can also be employed in recording materials which are based on the principle of photopolymerization, photosoftening or the rupture of microcapsules, or, when heat-sensitive or photosensitive diazonium salts, leuco dyes with oxidizing agent or colour lactones with Lewis acids are used.

0167Heat-sensitive recording material exploits the colour-imparting reaction between a colourless or weakly coloured base dye and an organic or inorganic colour developer; the recorded image being produced by heat-induced contact of the two materials. This type of heat- sensitive recording material is very widespread, not only as the recording medium for faxes, computers, etc., but also in many other fields, for example in label printing.

0168The heat-sensitive recording material according to the present invention is composed of a base, a heat-sensitive colour-forming recording layer on this base, and, optionally, a protective layer on the heat-sensitive, colour-forming recording layer. The heat-sensitive, colour-forming recording layer contains as its principal constituent a colour-imparting compound and a colour-developing compound, and also a compound of the formula (I). If a protective layer is present, the compound of the formula (I) can also be incorporated into the protective layer.

0169Heat-sensitive recording materials are described, for example, in JP-A-Hei 8-267 915.

0170Further fields of use are recording materials for dye diffusion transfer printing, thermal wax transfer printing and dot matrix printing, and for use with electrostatic, electrographic, electrophoretic, magnetographic and laser-electrophotographic printers, recorders or plotters. Of the materials mentioned, preference is given to recording materials for dye diffusion transfer printing as described for example in EP-A-507,734.

0171Compounds of the formula (I) can also be employed in inks (preferably for ink-jet printing) for example as described in US-A-5, 098, 477, the disclosure content of which is regarded as part of the present description. The invention therefore preferably also relates to an ink comprising at least one compound of the formula (I) as stabilizer. The ink, especially for ink- jet printing, contains preferably water. Inks contain the stabilizer of the formula (I) usually in a concentration of from 0.01 to 20% by weight, in particular from 0.5 to 10% by weight.

0172The photographic material according to this invention can be a black and white or can be a colour photographic material. A colour photographic material is preferred.

0173Examples of colour photographic materials are colour negative films, colour reversal films, colour positive films, colour photographic paper, colour reversal photographic paper, colour- sensitive materials for the dye diffusion transfer process or the silver dye bleach process.

0174Details of the photographic materials to be stabilized according to this invention and components which can be employed therein are given, inter alia, in GB-A-2, 319,523, DE-A-19,750,906, page 23, line 20 to page 105, line 32, and US-A-5,538,840, column 25, line 60 to column 106, line 31. These parts of US-A-5,538,840 are incorporated herein by way of reference.

0175The compounds of this invention can be introduced in any layer of a silver halide photographic material, however, they are preferably incorporated in a chromogenic layer, in particular in a layer containing a yellow coupler. They are used, for example, in a 1% to 200% weight ratio with the coupler, preferably 1 % to 100%. The compounds of the present invention can be used in combination with other conventional stabilizers that can be incorporated in the same layer or in a different layer. Examples of suitable conventional stabilizers are described in GB-A-2,319,523, DE-A-19,750,906 and US-A-5,538,840 and include in particular phenolic stabilizers, conventional hindered amine stabilzers, UV absorbers, preferably those of the hydroxyphenyl benztriazole type or of the hydroxyphenyl triazine class, and the like.

0176Examples of yellow couplers are also disclosed in US-A-5,538,840, column 33, line 3 to column 47, line 15.

0177Thus, further preferred embodiments of this invention are:

0178(1 ) A photographic material comprising on a substrate at least one layer containing a compound of the formula (I).

0179(2) A silver halide colour photographic material comprising a support having thereon at least one light-sensitive silver halide emulsion layer and optionally a non-light sensitive emulsion layer, characterized in that at least one light-sensitive layer contains a compound of the formula (I).

0180(3) A silver halide colour photographic material comprising a support having thereon a) at least one cyan-forming unit composed of a red-sensitive silver halide emulsion layer containing a cyan dye-forming coupler, b) at least one magenta-forming unit composed of a green-sensitive silver halide emulsion layer containing a magenta dye-forming coupler and c) at least one yellow-forming unit composed of a blue-sensitive silver halide emulsion layer containing a yellow dye-forming coupler, characterized in that the blue-sensitive layer contains a compound of the formula (I). A further embodiment of this invention is a method for stabilizing an organic material against degradation induced by light, heat or oxidation, which comprises incorporating into said organic material at least one compound of the formula (I).

0181The compounds of the formula (I) can be used in various proportions depending on the nature of the material to be stabilized, on the end use and on the presence of other additives.

0182In general, it is appropriate to use, for example, 0.01 to 5 % by weight of the compounds of the formula (I), relative to the weight of the material to be stabilized, preferably 0.05 to 2 %, in particular 0.05 to 1 %.

0183The compounds of the formula (I) can be added, for example, to the polymeric materials before, during or after the polymerization or crosslinking of the said materials. Furthermore, they can be incorporated in the polymeric materials in the pure form or encapsulated in waxes, oils or polymers.

0184In general, the compounds of the formula (I) can be incorporated in the polymeric materials by various processes, such as dry mixing in the form of powder, or wet mixing in the form of solutions or suspensions or also in the form of a masterbatch which contains the compounds of the formula (I) in a concentration of 2.5 to 25 % by weight; in such operations, the polymer can be used in the form of powder, granules, solutions, suspensions or in the form of latices.

0185The materials stabilized with the compounds of the formula (I) can be used for the production of mouldings, films, tapes, monofilaments, fibres, surface coatings and the like.

0186If desired, other conventional additives for synthetic polymers, such as antioxidants, UV absorbers, nickel stabilizers, pigments, fillers, plasticizers, corrosion inhibitors and metal deactivators, can be added to the organic materials containing the compounds of the formula (I).

0187Particular examples of said conventional additives are:

01881. 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- methoxymethylphenol, 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-di- methyl-6-(1 '-methylheptadec-1 '-yl)phenol, 2,4-dimethyl-6-(1 '-methyltridec-1 '-yl)phenol and mixtures thereof.

01891.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioc- tyIthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethyiphenol, 2,6-di-dodecylthiomethyl- 4-nonylphenol.

01901.3. 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- butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis-(3,5-di-tert-butyl-4- hydroxyphenyl) adipate.

01911.4. Tocopherols. for example α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures thereof (Vitamin E).

01921.5. Hvdroxylated 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-hydroxyphe- nyl)disulfide.

01931.6. 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-me- thylphenol), 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)dicyclopentadi- ene, bis[2-(3'-tert-butyl-2'-hydroxy-5'-methylbenzyl)-6-tert-butyl-4-methylphenyljterephthalate, 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.

01941.7. O-, N- and S-benzyl compounds, for example 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxydi- benzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzyImercaptoacetate, 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-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

01951.8. 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.

01961.9. Aromatic hvdroxybenzyl 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.

01971.10. Triazine Compounds, for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hy- droxyanilino)-1 ,3,5-thazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1 ,3,5- triazine, 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-hydroxy- benzyl)isocyanurate, 1 ,3,5-ths(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- hydroxyphenylpropionyl)-hexahydro-1 ,3,5-triazine, 1 ,3,5-tris(3,5-dicyclohexyl-4-hydroxyben- zyl)isocyanurate. 1.11. Benzylphosphonates, 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-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

01981.12. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N- (3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

01991.13. 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, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicycIo[2.2.2]octane.

02001.14. Esters of β-(5-tert-butyl-4-hvdroxy-3-methylphenyl)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, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'- bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

02011.15. 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.

02021.16. 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.

02031.17. 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)- hydrazide, N,N'-bis[2-(3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyloxy)ethyl]oxamide (Naugard^®XL-1 supplied by Uniroyal).

02041.18. Ascorbic acid (vitamin C)

02051.19. Aminic antioxidants, for example N,N'-di-isopropyl-p-phenylenediamine, N,N'-di-sec- butyl-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'-dicyclohexyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, N,N'-bis(2-naph- thyl)-p-phenyienediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1 ,3-dimethylbutyl)- N'-phenyl-p-phenylenediamine, N-(1 -methylheptyl)-N'-phenyl-p-phenylenediamine, N-cyclo- hexyl-N'-phenyl-p-phenlenediamine, 4-(p-toluenesulfamoyl)diphenylamine, N,N'-dimethyl- N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4-isopropoxy- diphenylamine, N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine, N-phe- nyl-2-naphthylamine, octylated diphenylamine, for example p,p'-di-tert-octyldiphenylamine, 4- n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylamino- phenol, 4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine, 2,6-di-tert-butyl-4-dime- thylaminomethylphenol, 2,4'-diaminodiphenyimethane, 4,4'-diaminodiphenylmethane, N,N,N',N'-tetramethyl-4,4'-diaminodiphenylmethane, 1 ,2-bis[(2-methylphenyl)amino]ethane, 1 ,2-bis(phenylamino)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- octyldiphenylamines, a mixture of mono- and dialkylated nonyldiphenylamines, a mixture of mono- and dialkylated dodecyldiphenylamines, a mixture of mono- and dialkylated isopro- pyl/isohexyldiphenylamines, a mixture of mono- und dialkylated tert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1 ,4-benzothiazine, phenothiazine, a mixture of mono- und dialkylated tert-butyl/tert-octylphenothiazines, a mixture of mono- und dialkylated tert-octyl-phe- nothiazines, N-allylphenothiazin, N,N,N',N'-tetraphenyl-1 ,4-diaminobut-2-ene, N,N-bis- (2,2,6, 6-tetramethyl-piperid-4-yl-hexamethylenediamine, bis(2,2,6,6-tetramethylpiperid-4-yl)- sebacate, 2,2,6,6-tetramethylpiperidin-4-one, 2,2,6, 6-tetramethylpiperidin-4-oi.

02062. UV absorbers and light stabilisers

02072.1. 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)benzothazole, 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- ethylhexyloxy)-carbonylethyl]-2'-hydroxyphenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hy- droxy-5'-(2-methoxycarbonylethyl)phenyl)-5-chloro-benzotriazole, 2-(3'-tert-butyl-2'-hydroxy- 5'-(2-methoxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxy- carbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)carbonylethyl]-2'- hydroxyphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(3'- tert-butyl-2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)phenylbenzothazole, 2,2'-methylene-bis- [4-(1 ,1 ,3,3-tetramethylbutyl)-6-benzothazole-2-ylphenol]; the transeste fication product of 2- [3'-tert-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxyphenyl]-2H-benzotriazole with polyethy¬

0208lene glycol 300; [R -CH₂CH — COO-CH-CHr}- where R = 3'-tert-butyl-4'-hydroxy-5'-2H-

0209benzotriazol-2-ylphenyl, 2-[2'-hydroxy-3'-(α,α-dimethylbenzyl)-5'-(1 ,1 ,3,3-tetramethylbutyl)- phenyljbenzotriazole; 2-[2'-hydroxy-3'-(1 ,1 ,3,3-tetramethylbutyl)-5'-(α,α-dimethylbenzyl)- phenyljbenzotriazole.

02102.2. 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.

02112.3. Esters of substituted and unsubstituted benzoic acids, as for example 4-tertbutyl-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, hexadecyi 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl 3,5-di-tert-butyl-4-hydroxy- benzoate, 2-methyi-4,6-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate.

02122.4. 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-methoxy-cinna- mate, butyl α-cyano-β-methyl-p-methoxy-cinnamate, methyl α-carbomethoxy-p-methoxycin- namate and N-(β-carbomethoxy-β-cyanovinyl)-2-methylindoline.

02132.5. Nickel compounds, for example nickel complexes of 2,2'-thio-bis-[4-(1 ,1 ,3,3-tetrame- thylbutyl)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- nyl undecylketoxime, nickel complexes of 1-phenyI-4-lauroyl-5-hydroxypyrazole, with or without additional ligands.

02142.6. Sterieally hindered amines, for example bis(2,2,6,6-tetramethyl-4-pipehdyl)sebacate, bis(2,2,6,6-tetramethyl-4-pipehdyl)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-pi- peridyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzylmalonate, the condensate of 1 -(2-hydroxy- ethyl)-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-butane-tetracarboxylate, 1 ,1 '-(1 ,2-ethanediyl)-bis(3, 3,5,5- tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy-2, 2,6,6- tetramethylpiperidine, bis(1 , 2,2,6, 6-pentamethylpipehdyl)-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]decan-2,4-dione, bis(1 -octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1 -octyloxy-2,2,6,6-tetrame- thylpiperidyl)succinate, linear or cyclic condensates of N,N'-bis-(2,2,6,6-tetramethyl-4-piperi- dyl)hexamethylenediamine 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-pen- tamethy!piperidyl)-1 ,3,5-triazine and 1 ,2-bis-(3-aminopropylamino)ethane, 8-acetyl-3-dode- cyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1 -(2,2,6,6-tetrame- thyl-4-pipehdyl)pyrrolidin-2,5-dione, 3-dodecyl-1 -(1 ,2,2,6,6-pentamethyl-4-piperidyl)pyrroli- dine-2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, a condensation product of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and 4-cyclohexylamino-2,6-dichloro-1 ,3,5-triazine, a condensation product of 1 ,2-bis(3-ami- nopropylamino)ethane and 2,4,6-trichioro-1 ,3,5-triazine as well as 4-butylamino-2,2,6,6-te- tramethylpiperidine (CAS Reg. No. [136504-96-6]); N-(2,2,6,6-tetramethyl-4-piperidyl)-n-do- decylsuccinimid, N-(1 ,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimid, 2-undecyl- 7,7,9, 9-tetramethyl-1 -oxa-3,8-diaza-4-oxo-spiro[4,5]decane, a reaction product of 7,7,9,9- tetramethyl-2-cycloundecyl-1 -oxa-3,8-diaza-4-oxospiro [4,5]decane und epichlorohydrin, 1 ,1 - bis(1 , 2,2,6, 6-pentamethyl-4-pipehdyloxycarbonyl)-2-(4-methoxyphenyl)ethene, N,N'-bis- formyl-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine, diester of 4-methoxy- methylene-malonic acid with 1 ,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly[methylpropyl-3- oxy-4-(2,2,6,6-tetramethyl-4-piperidyl)]siloxane, reaction product of maleic acid anhydride-α- olefin-copolymer with 2,2,6,6-tetramethyl-4-aminopipehdine or 1 , 2,2,6, 6-pentamethyl-4- aminopiperidine.

02152.7. Oxamides. for example 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy- 5,5'-di-tert-butoxanilide, 2,2'-didodecyioxy-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.

02162.8. 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-pro- pyloxyphenyl)-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-dimethylphe- nyl)-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-butyloxy-propoxy)phenyl]-4,6-bis(2,4-dimethyl)-1 ,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-octyloxy-propyloxy)phenyl]-4,6-bis(2,4-dimethyl)-1 ,3,5- triazine, 2-[4-(dodecyloxy/thdecyloxy-2-hydroxypropoxy)-2-hydroxy-phenyl]-4,6-bis(2,4-di- methylphenyl)-1 ,3,5-triazine, 2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxy-propoxy)phenyl]-4,6- bis(2,4-dimethylphenyl)-1 ,3,5-triazine, 2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1 ,3,5- triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1 ,3,5-triazine, 2,4,6-tris[2-hydroxy-4-(3- butoxy-2-hydroxy-propoxy)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.

02173. 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.

02184. Phosphites and phosphonites, for example triphenyl phosphite, diphenyl alkyl phosphites, phenyl dialkyl phosphites, tris(nonylphenyl) phosphite, trilauryl phosphite, trioctadecyl phosphite, distearyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di- tert-butyl-4-methylphenyl)-pentaerythritol diphosphite, diisodecyloxypentaeryth tol diphosphite, bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite, bis(2,4,6-tris(tert- butylphenyl)pentaerythritol diphosphite, tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-bu- tylphenyl) 4,4'-biphenylene diphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-di- benz[d,g]-1 ,3,2-dioxaphosphocin, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-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, 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'-tetra-tert-butyl-1 ,1'-biphenyI-2,2'-di- yl)phosphite.

02195. Hvdroxylamines, 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-octadecylhy- droxylamine, N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamine derived from hydrogenated tallow amine.

02206. Nitrones, for example, N-benzyl-alpha-phenyl-nitrone, N-ethyl-alpha-methyl-nitrone, N-oc- tyl-alpha-heptyl-nitrone, N-lauryl-alpha-undecyl-nitrone, N-tetradecyl-alpha-tridcyl-nitrone, N- hexadecyl-alpha-pentadecyl-nitrone, N-octadecyl-alpha-heptadecyl-nitrone, N-hexadecyl- alpha-heptadecyl-nitrone, N-ocatadecyl-alpha-pentadecyl-nitrone, N-heptadecyl-alpha-hep- tadecyl-nitrone, N-octadecyl-alpha-hexadecyl-nitrone, nitrone derived from N,N-dialkylhy- droxylamine derived from hydrogenated tallow amine.

02217. Thiosvnerqists, for example, dilauryl thiodipropionate or distearyl thiodipropionate.

02228. 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.

02239. Polyamide stabilisers, for example, copper salts in combination with iodides and/or phosphorus compounds and salts of divalent manganese.

022410. Basic co-stabilisers, 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 cinoleate and potassium palmitate, antimony pyrocatecholate or zink pyrocatecholate.

022511. 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).

022612. Fillers and reinforcing agents, for example, calcium carbonate, silicates, glass fibres, glass bulbs, 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.

022713. Other additives, for example, plasticisers, lubricants, emulsifiers, pigments, rheology additives, catalysts, flow-control agents, optical brighteners, 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-4316611 ; DE-A-4316622; DE-A-4316876; EP-A-0589839 or EP-A-0591102 or 3-[4-(2-acetoxyethoxy)- phenyl]-5,7-di-tert-butyl-benzofuran-2-one, 5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phe- nyl]benzofuran-2-one, 3,3'-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)benzofuran-2- one], 5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one, 3-(4-acetoxy-3,5-dimethylphe- nyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(3,5-dimethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butyl- benzofuran-2-one, 3-(3,4-dimethylphenyl)-5,7-di-tert-butyl-benzofuran-2-one, 3-(2,3-di- methylphenyl)-5,7-di-tert-butyl-benzofuran-2-one.

0228The weight ratio of the compounds of the formula (I) to the conventional additives may be for example 1 :0.5 to 1 :5.

0229This invention is illustrated in more detail by the following Examples. All percentages are by weight, unless otherwise indicated. The compounds disclosed in Examples 1A), 1 B), 1 C), 4A) and 4B) relate to a particular preferred embodiment of the present invention.

EXAMPLE 1 :

0231A) Preparation of the intermediate of the formula

0232<img file="WO0031069A1_D0014.tif" />

02331 ) Preparation of 1-(2-nitro-2-methylpropylamino)propan-2-ol.

0234Following the procedure described below in EXAMPLE 4A, step 1 , 526.3 g (6.66 mol) of 1-amino-2-propanol (95 %) are reacted with 561.6 g (6.05 mol) of 2-nitropropane (96 %) and 181.7 g (6.05 mol) of paraformaldehyde in 100 ml of isopropanol to give the product which is used in the following reaction without any isolation.

02352) Preparation of 1 -(2-amino-2-methylpropylamino)propan-2-ol. Following the procedure described below in EXAMPLE 4A, step 2, the mixture of above step 1 is hydrogenated by using 100 g of Raney Ni as a catalyst. A white oil with a boiling point of 116° - 120°C at 13.3 mbar is obtained.

02363) Preparation of 1 -(2-hydroxypropyl)-3,3,5,5-tetramethylpiperazin-2-one. Following the procedure described below in EXAMPLE 4A, step 3, 250 g (1.71 mol) of 1-(2-amino-2-methylpropylamino)propan-2-ol are reacted with 306.2 g (2.57 mol) of chloroform and 1509 ml of acetone in the presence of 410.4 g (10.26 mol) of sodium hydroxide in 410 ml of water. A yellow oil with a boiling point of 137° - 140°C at 1.1 mbar is obtained.

02374) The intermediate of the above formula is prepared by adding 107 g (0.5 mol) of dimethylsulfoxide drop by drop to a solution of 63.5 g (0.5 mol) of oxalyi chloride in 800 ml of dichloromethane cooled to -60°C. After the addition, a solution of 1-(2-hydroxypropyl)- 3,3,5, 5-tetramethylpiperazin-2-one in 300 ml of dichloromethane are slowly added, keeping the temperature at -60°C. After 20 minutes, 101 g (1 mol) of triethylamine are added. After additional 30 minutes, the temperature is increased to room temperature. Then, the mixture is filtered and evaporated under vacuum. The row material is purified by distillation (129°C/1 mmHg). The product is recovered as a yellow oil. The yield is 80 % of theory.

0238¹H NMR: 4.03 (s, 2H.: 3.11 (s, 2H); 2.018 (s, 3H); 1.24 (s, 6H); 1.09 (s, 6H)

0239B) Preparation of the intermediate of the formula

0240<img file="WO0031069A1_D0015.tif" />

0241At room temperature, 50 g of Pt (5 %) supported on carbon with 50 % water are added to a mixture of 132.4 g (0.62 mol) of 3,3,5,5-tetramethyl-1 -(2-oxopropyl)piperazin-2-one and 36.2 g (0.31 mol) of hexamethylendiamine in methanol. The mixture is hydrogenated at 70°C and 35 bar for 20 hours. Then, the mixture is filtered and the organic phase is washed with water, dehydrated on sodium sulphate and evaporated under vacuum. The product is recovered as a yellow resin. The yield is 93 % of theory.

0242Η NMR: 3.37 (dd, 2H); 3.17 (s, 4H); 3.14 (dd, 2H); 2.82 (sext, 2H); 2.61 - 2.40 (m, 4H); 1.33 (m, 4H); 1.27 (s, 12H); 1.22 (s, 4H); 1.10 (s, 12H); 0.96 (d, 6H)

0243C) Preparation of the compound of the formula

0244<img file="WO0031069A1_D0016.tif" />

024546.5 g (0.21 mol) of 2-tert-butylamino-4,6-dichlorotriazine in 500 ml of xylene are added to a solution of 125 g (0.23 mol) of the intermediate described under B) in 300 ml of xylene. The solution is heated at 60°C for 2 hours, under stirring. Then, 25.2 g (0.63 mol) of NaOH in 50 ml of water are added. The mixture is heated to reflux for 5 hours, the water being removed by azeotropic distillation. Subsequently, the mixture is cooled to 60°C and 29 g (0.21 mol) of sodium carbonate in 50 ml of water are added and the mixture is refluxed for additional 24 hours, the water being removed by azeotropic distillation. Then, the mixture is cooled and filtered. The organic phase is dehydrated on sodium sulphate and evaporated under vacuum. 153.3 g of the product are recovered. The yield is 98 % of theory.

0246Melting point: 96° - 99°C

0247EXAMPLE 2 : Preparation of the compound of the formula <img file="WO0031069A1_D0017.tif" />

0248The compound is prepared in analogy to the method described in EXAMPLE 1 , using the appropriate starting materials.

0249Melting point: 130° - 140°C (yellow powder)

0250EXAMPLE 3: Preparation of the compound of the formula

0251<img file="WO0031069A1_D0018.tif" />

02525 g of paraformaldehyde are added to a solution of 36.1 g (0.055 mol) of the compound of EXAMPLE 1C in tert-amyl alcohol. The mixture is heated to 80°C and 7.6 g (0.165 mol) of formic acid dissolved in 10 ml of tert-amyl alcohol are slowly added. The mixture is then stirred for 3 hours at 80°C. Then, 50 ml of toluene are added, the temperature being cooled down to room temperature. Subsequently, a solution of 6.6 g (0.165 mol) of sodium hydroxide in 50 ml of water is slowly added. After stirring for Vz hour , the organic phase is separated , washed twice with water, dried over anhydrous sodium sulfate, filtered and evaporated under vacuum (80°C / 1.3 mbar). Melting point: 95° - 99°C

EXAMPLE 4:

0254A) Preparation of the intermediate of the formula

0255<img file="WO0031069A1_D0019.tif" />

02561 ) Preparation of 2-(2-nitro-2-methyl-propylamino)ethanol.

0257607.8 g (6.55 mol) of 2-nitropropane and 100 ml of water are added to a solution of 450 g (7.40 mol) of ethanolamine in 1000 ml of isopropanol. The solution is stirred at room temperature and 225.4 g (7.5 mol) of paraformaldehyde and 7 ml of 20 % agueous solution of sodium hydroxide (% w/v) are added under stirring and maintaining the temperature at room temperature for 16 hours. The mixture is then heated to 50°C with nitrogen being bubbled into the mixture to eliminate the formaldehyde in excess. The mixture obtained is used for the following reaction without any isolation of the product.

02582) Preparation of 2-(2-amino-2-methyl-propylamino)ethanol.

0259The mixture of 1 ) is transferred into an autoclave and 100 g of Raney Ni are added. The autoclave is closed and purged with nitrogen. Hydrogen is added until the pressure is 50 bars. The mixture is maintained under a hydrogen pressure of 50 bars at room temperature and under stirring for 8 hours. Subsequently, the mixture is heated to 50°C at the same pressure. The catalyst is then separated off by filtration and the mixture is distilled under vacuum. A white oil with a boiling point of 100° - 105°C at 13.3 mbar is obtained.

02603) Preparation of 1-(2-hydroxyethyl)-3,3,5,5-tetramethylpiperazin-2-one.

0261244.2 g (2.05 mol) of chloroform are added to 180 g (1.36 mol) of 2-(2-amino-2-methyl- propylamino)ethanol in 1204 ml of acetone. The mixture is cooled to 5°C under stirring and a solution of 327 g (8.18 mol) of sodium hydroxide in 327 ml of water is slowly added, the temperature of the mixture being maintained at 0° - 5°C during the addition. The mixture is then stirred at this temperature for further 2 hours and at room temperature for 15 hours. Subsequently, the pH of the aqueous solution is corrected to 11 and the mixture is stirred for further 4 hours. Then, the mixture is filtered and the residue is washed with acetone. The filtrate and the acetone of washing are collected and evaporated under vacuum (70°C/24 mbar). The residue is distilled giving a white oil with a boiling point of 115°C at 2.66 mbar. After cooling a solid product with a melting point of 91 ° - 93°C is obtained.

02624) Preparation of 1-(2-hydroxyethyl)-3,3,4,5,5-pentamethylpiperazin-2-one.

026324.3 g (0.78 mol) of paraformaldehyde are added to a solution of 120 g (0.6 mol) of 1-(2-hydroxyethyl)-3,3,5,5-tetramethylpiperazin-2-one in 300 ml of tert-amyl alcohol. The mixture is then heated to 80°C and 35.8 g (0.78 mol) of formic acid dissolved in 30 ml of tert-amyl alcohol are slowly added. Then, the mixture is maintained at 80°C for further 1 hour and cooled to 50°C. Subsequently, 250 ml of toluene and 100 ml of water are added. The mixture is then stirred and 33 g (0.825 mol) of sodium hydroxide dissolved in 60 ml of water are slowly added. The organic phase is separated, washed with water, dried over anhydrous sodium sulfate, filtered and evaporated under vacuum (60°C/10 mbar). A white solid with a melting point of 77° - 80°C is obtained.

02645) The intermediate of the above formula is prepared in analogy to the procedure described in EXAMPLE 1A, step 4, starting from 1 -(2-hydroxyethyl)-3,3,4,5,5-pentamethylpiperazin-2- one. A brown oil is obtained.

0265¹H NMR: 9.50 (s, 1 H); 4.06 (s, 2H); 3.07 (s, 2H); 2.20 (s, 3H); 1.27 (s, 6H); 1.06 (s, 6H)

0266B) Preparation of the intermediate of the formula <img file="WO0031069A1_D0020.tif" />

0267This intermediate is prepared in analogy to the procedure described in EXAMPLE 1 B, starting from the intermediate of the above step A.

0268C) Preparation of the compound of the formula

0269<img file="WO0031069A1_D0021.tif" />

0270This compound is prepared in analogy to the method described in EXAMPLE 1 C, using the reagent of the above step B. The product obtained is a yellow powder.

0271Melting point: 78° - 81 °C

0272EXAMPLE 5: Preparation of the compound of the formula <img file="WO0031069A1_D0022.tif" />

0273A solution of 15 g of the product of EXAMPLE 1C, 4 g (0.02 mol) of acetic anhydride and 4 g (0.02 mol) of triethylamine in 150 ml of dichloromethane is refluxed for 5 hours. After cooling, 30 ml of a 40 % solution of potassium carbonate is added. The organic phase is separated, dried over anhydrous sodium sulfate, filtered and evaporated under vacuum (80°C/1.3mbar). A white powder is obtained.

0274Melting point: 103° - 107°C

0275EXAMPLE 6: Preparation of the compound of the formula

0276<img file="WO0031069A1_D0023.tif" />

0277The compound is prepared in analogy to the method described in EXAMPLE 5, using the compound of EXAMPLE 2.

0278Melting point: 122° - 127°C (yellow powder)

0279EXAMPLE 7: Preparation of the compound of the formula <img file="WO0031069A1_D0024.tif" />

0280A solution of 50 g of the compound of EXAMPLE 2C and 8.9 g (0.024 mol) of 2,4-bis{dibutylamino}-6-chloro-{1 ,3,5}-triazine in 250 ml of xylene is allowed to react for 4 hours at 140°C. After cooling to 60°C, 0.96 g (0.024 mol) of sodium hydroxide and 4 g of potassium carbonate in 10 ml of water are added. The mixture is heated to reflux and the reaction water is azeotropically eliminated. After 6 additional hours, the mixture is cooled to 60°C, diluted with 50 ml of xylene, filtered and concentrated under vacuum at 140°C/1 mbar. A yellow powder is obtained.

0281Melting point: 60° - 64°C

0282EXAMPLE 1-1 : Light stabilizing action in polypropylene tapes.

02831 g of each of the compounds listed in Table 1-1 , 1 g of ths[2,4-di-tert-butylphenyl] phosphite,

02840.5 g of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 1 g of calcium stearate are mixed in a turbomixer with 1000 g of polypropylene powder

0285(PP ^®MOPLEN S SF ) having a melt index of 3.7 (measured at 230°C and 2.16 Kg).

0286The mixtures are extruded at 200-220°C to give polymer granules which are subsequently converted to stretched tapes of 50 μm thickness and 2.5 mm width, using a semi-industrial type of apparatus (^®Leonard-Sumirago (VA) - Italy) and working under the following conditions:

0287Extruder temperature: 210-230°C

0288Head temperature: 240-260°C

0289Stretch ratio: 1 :6 The tapes thus prepared are mounted on a white card and exposed in a Weather-O-Meter 65 WR (ASTM D 2565-85) with a black panel temperature of 63°C.

0290The residual tenacity is measured, by means of a constant velocity tensometer, on a sample taken after various light exposure times; from this, the exposure time (in hours) required to halve the initial tenacity (T₅₀) is measured.

0291By way of comparison, tapes prepared under the same conditions as indicated above, but without the addition of the stabilizers of the present invention, are exposed.

0292The results obtained are shown in Table 1-1.

0293Table 1-1 :

0294Stabilizer Isoihours)

0295Without stabilizer 520 Compound of EXAMPLE 1 C 2620 Compound of EXAMPLE 3 2600

0296The above results show that the compounds of this invention are effective light stabilizers.

0297EXAMPLE I-2: Light stabilizing action in polypropylene fibres.

02982.5 g of each of the compounds listed in Table I-2, 1 g of tris(2,4-di-t-butylphenyl) phosphite, 1 g of calcium monoethyl 3,5-di-t-butyl-4-hydroxybenzyl-phosphonate,

02991 g of calcium stearate and 2.5 g of titanium dioxide are mixed in a slow mixer with

03001000 g of polypropylene powder (PP ^®MOPLEN FLF 20) having a melt index = 12.2 g/10 min (measured at 230°C and 2.16 kg).

0301The mixtures are extruded at 200-230°C to obtain polymer granules which are then converted into fibres using a pilot-type apparatus (^®Leonard-Sumirago(VA), Italy) and operating under the following conditions: Extruder temperature: 230-245°C

0302Head temperature: 255-260°C

0303Draw ratio : 1 :3.5

0304Linear density: 1 1 dtex per filament

0305The fibres prepared in this way are exposed, after mounting on white cardboard, in a 65WR Weather-O-Meter (ASTM D2565-85) with a black panel temperature of 63°C.

0306For samples taken after various times of exposure to the light, the residual tenacity is measured using a constant-speed tensometer, and the exposure time in hours needed to halve the initial tenacity (T₅₀) is then calculated.

0307For purposes of comparison, fibres prepared under the same conditions as stated above, but without adding the stabilizers of the present invention, are also exposed.

0308The results are shown in Table I-2.

0309Table I-2:

0310Stabilizer TRΠ (hours)

0311Without stabilizer 310

0312Compound of EXAMPLE 1C 2790

0313Compound of EXAMPLE 3 2830

0314The above results show that the compounds of this invention are effective light stabilizers.

0315EXAMPLE 11-1 : Stabilization of a gray pigmented polycarbonate/acrylonitrile-butadiene- styrene (PC/ABS) blend. A commercial PC/ABS blend (^®Cycoloy MC 8002) pigmented with 1 % by weight of ^®Gray 9779 from Uniform Color Company is stabilized by addition of 1 % by weight of 2-(2'-hydroxy-3',5'-bis(1 ",1 "-dimethylbenzyl)phenyl)benzotriazole and 0.5% by weight of the compound indicated in Table 11-1. A sample containing only the 1 % by weight of the benzotriazole stabilizer and an unstabilized sample - both containing 1 % by weight of gray pigment - serve as comparison.

0316Izod bars (2.5"L x 0.5"W x 0.125"W) are prepared by injection molding on a ^®BOY 30 machine, barrel temperature 246° - 268°C, die temperature 268°C. Accelerated weathering is performed using an ^®Atlas Ci65A Weather-O-meter (XAW), operating in "Dry XAW" mode (ASTM G26-90, method C). After regular intervals, the color change ΔE according to DIN 6174 is determined. The results are listed in Table 11-1.

0317Table 11-1 :

0318<img file="WO0031069A1_D0025.tif" />

0319^*) 2-(2'-hydroxy-3',5'-bis(1 ",1 "-dimethylbenzyl)phenyl)benzotriazole

0320The PC/ABS samples stabilized according to this invention show an excellent color stability.

0321EXAMPLE II-2: Stabilization of a white pigmented polycarbonate/acrylonitrile-butadiene- styrene (PC/ABS) blend. Samples are prepared from a commercial PC/ABS blend (^®Cycoloy MC 8002) as described in EXAMPLE 11-1 except that TiO₂ (^®Tiona RCL-4 rutile; ^®SCM chemicals) is used as pigment. Weathering and assessment is carried out as described in EXAMPLE 11-1. The results are shown in Table II-2. Table 11-2:

0322<img file="WO0031069A1_D0026.tif" />

0323^*) 2-(2'-hydroxy-3',5'-bis(1 ", 1 "-dimethylbenzyl)phenyl)benzotriazole

0324The PC/ABS samples stabilized according to this invention show an excellent color stability, particularly at prolonged exposure intervals.

0325Abbreviations used in the following EXAMPLES III-1 to III-5:

0326CoupYI : Compound of the formula

0327<img file="WO0031069A1_D0027.tif" />

0328CoupY2: Compound of the formula

0329<img file="WO0031069A1_D0028.tif" />

0330<img file="WO0031069A1_D0029.tif" />Ha1 : Compound of the formula <img file="WO0031069A1_D0030.tif" />

0331Su1 : Compound of the formula

0332<img file="WO0031069A1_D0031.tif" />

0333Coaddl : Compound of the formula

0334<img file="WO0031069A1_D0032.tif" />

0335Coadd2: Compound of the formula

0336<img file="WO0031069A1_D0033.tif" />

0337EXAMPLE 111-1 : Stabilization of photographic layers.

0338Chromogenic photographic layers are prepared by hand-coating a gelatine emulsion containing silver bromide, yellow coupler and an additive of this invention on a polyethylene- coated paper.

0339The composition of the layer is as given in the following table (amounts are in mg/m2).

0340<img file="WO0031069A1_D0034.tif" /><img file="WO0031069A1_D0035.tif" />

0341The layers are dried for 7 days in a ventilated cabinet. The dried samples are exposed to white light through a stepwedge of 0.3 logE exposure steps. They are developed with the P94 process for negative colour paper from ®Agfa-Gevaert, following the manufacturer's recommendations.

0342After exposure and processing, the remission density of the yellow dye is measured in the blue channel. The results are listed in Table 111-1.

0343Table 111-1 :

0344<img file="WO0031069A1_D0036.tif" />

0345These results show that the compounds of the present invention improve the maximal dye yield.

0346EXAMPLE 111-2: Stabilization of photographic layers.

0347Chromogenic photographic layers are prepared by hand-coating a gelatine emulsion containing silver bromide, yellow coupler and an additive of this invention on a polyethylene- coated paper.

0348The composition of the layer is as given in the following table (amounts are in mg/m²).

0349<img file="WO0031069A1_D0037.tif" />

0350<img file="WO0031069A1_D0038.tif" />

0351The layers are dried for 7 days in a ventilated cabinet. The dried samples are exposed to white light through a stepwedge of 0.3 logE exposure steps. They are developed with the P94 process for negative colour paper from ^®Agfa-Gevaert, following the manufacturer's recommendations.

0352After exposure and processing, the remission density of the yellow dye is measured in the blue channel. The results are listed in Table III-2.

0353Table III-2:

0354<img file="WO0031069A1_D0039.tif" />

0355These results show that the compounds of the present invention improve the maximal dye yield.

0356EXAMPLE HI-3: Stabilization of photographic layers.

0357Chromogenic photographic layers are prepared by hand-coating a gelatine emulsion containing silver bromide, yellow coupler and an additive of this invention on a polyethylene- coated paper.

0358The composition of the layer is as given in the following table (amounts are in mg/m²).

0359<img file="WO0031069A1_D0040.tif" />

0360<img file="WO0031069A1_D0041.tif" />

0361The layers are dried for 7 days in a ventilated cabinet. The dried samples are exposed to white light through a stepwedge of 0.3 logE exposure steps. They are developed with the P94 process for negative colour paper from ^®Agfa-Gevaert, following the manufacturer's recommendations.

0362After exposure and processing, the remission density of the yellow dye is measured in the blue channel. The samples are then exposed in an ^®Atlas weather-O-meter so as to receive 60kJ/cm² light energy. The temperature is 43°C and the relative humidity is 50%. The density loss (-ΔD) starting from a blue-density of 1 (OD = 1) is determined. The results are listed in Table III-3.

0363Table

0364<img file="WO0031069A1_D0042.tif" />

0365These results show that the compounds of the present invention improve the light stability of yellow photographic layers.

0366EXAMPLE 4: Stabilization of photographic layers. Chromogenic photographic layers are prepared by hand-coating a gelatine emulsion containing silver bromide, yellow coupler and an additive of this invention on a polyethylene- coated paper.

0367The composition of the layer is as given in the following table (amounts are in mg/m²).

0368<img file="WO0031069A1_D0043.tif" />

0369The layers are dried for 7 days in a ventilated cabinet. The dried samples are exposed to white light through a stepwedge of 0.3 logE exposure steps. They are developed with the P94 process for negative colour paper from ^®Agfa-Gevaert, following the manufacturer's recommendations.

0370After exposure and processing, the remission density of the yellow dye is measured in the blue channel. The samples are then exposed in an ^®Atias weather-O-meter so as to receive 60kJ/cm² light energy. The temperature is 43°C and the relative is humidity 50%. The density loss (-ΔD) starting from a blue-density of 1 (OD = 1) is determined. The results are listed in Table III-4.

0371Table III-4:

0372<img file="WO0031069A1_D0044.tif" /><img file="WO0031069A1_D0045.tif" />

0373These results show that compounds of the present invention improve the light stability of yellow photographic layers.

0374EXAMPLE III-5: Stabilization of photographic layers.

0375Chromogenic photographic layers are prepared by hand-coating a gelatine emulsion containing silver bromide, yellow coupler and an additive of this invention in combination with a co-stabilizer on a polyethylene-coated paper.

0376The composition of the layer is as given in the following table (amounts are in mg/m²).

0377<img file="WO0031069A1_D0046.tif" />

0378The layers are dried for 7 days in a ventilated cabinet. The dried samples are exposed to white light through a stepwedge of 0.3 logE exposure steps. They are developed with the P94 process for negative colour paper from ^®Agfa-Gevaert, following the manufacturer's recommendations.

0379After exposure and processing, the remission density of the yellow dye is measured in the blue channel. The samples are then exposed in an ^®Atlas weather-O-meter so as to receive 60kJ/cm² light energy. The temperature is 43°C and the relative humidity is 50%. The density loss (-ΔD) starting from a blue-density of 1 (OD = 1 ) is determined. The results are listed in Table III-5. Table 111-5:

0380<img file="WO0031069A1_D0047.tif" />

0381These results show that the compounds of the present invention improve the efficiency of classical stabilizers used in yellow photographic layers.