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Title:
COLOR STABILIZATION OF CORK AND COLORED WOODS BY THE COMBINED USE OF INORGANIC AND ORGANIC UV-ABSORBERS
Document Type and Number:
WIPO Patent Application WO/2007/051741
Kind Code:
A1
Abstract:
The instant invention relates to a method for the color stabilization of cork and specific colored woods by the combined use of a small amount of inorganic UV-absorbers and an excess of organic UV-absorbers in a protective coating. A further aspect of the invention is the use of such a UV-absorber combination for the color stabilization of cork and specific colored woods.

Inventors:
SCHALLER CHRISTIAN MARCUS (CH)
MEYER RAPHAEL (CH)
Application Number:
PCT/EP2006/067743
Publication Date:
May 10, 2007
Filing Date:
October 25, 2006
Export Citation:
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Assignee:
CIBA SC HOLDING AG (CH)
SCHALLER CHRISTIAN MARCUS (CH)
MEYER RAPHAEL (CH)
International Classes:
B27K3/52; B27K7/00; C09D7/48
Domestic Patent References:
WO2004094120A12004-11-04
Foreign References:
US4505986A1985-03-19
EP0943665A11999-09-22
EP0440580A21991-08-07
Attorney, Agent or Firm:
CIBA SPECIALTY CHEMICALS HOLDING INC. (Klybeckstrasse 141, Basel, CH)
Download PDF:
Claims:

Claims

1. A method for protecting cork or wood substrates from discoloration wherein the wood substrate is selected from the group consisting of beech, alder, meranti, oak, cherry, teak, nut redwood, mahogany eucalyptus, american beech, durian, red cedar, leichhardt tree, champa, rubberwood, taiwan ash, campher tree, zebra wood, makha, rosewood, rain tree and ironwood; comprising applying to the cork or wood substrate a coating, which coating contains

a) an organic UV-absorber selected from the group consisting of the hydroxybenzophenone, hydroxyphenylbenzotriazole, oxanilide and hydroxyphenyltriazine UV-absorbers or mixtures thereof; and

b) an inorganic UV-absorber selected from the group consisting of transparent iron oxide, transparent titanium dioxide, transparent zinc oxide, transparent cerium oxide and carbon black or mixtures thereof; wherein the weight ratio of organic UV-absorber to inorganic UV-absorber is from 1000:1 to 10:1.

2. A method according to claim 1 wherein the wood substrate is selected from the group consisting of beech, alder, meranti, oak, cherry, teak, nut redwood and mahogany.

3. A method according to claim 1 wherein the substrate is cork or alder.

4. A method according to claim 1 wherein the substrate is cork.

5. A method according to claim 1 wherein the inorganic UV-absorber is a transparent iron oxide or carbon black or a mixture thereof.

6. A method according to claim 1 wherein the hydroxybenzophenone is of formula I

the 2-hydroxyphenylbenzotriazole is of formula Na, Mb or Nc

the 2-hydroxyphenyltriazine is of formula

and the oxanilide is of formula (IV)

(IV) ; wherein

in the compounds of the formula (I) v is an integer from 1 to 3 and w is 1 or 2 and the substituents Z independently of one another are hydrogen, halogen, hydroxyl or alkoxy having 1 to 12 carbon atoms;

in the compounds of the formula (Ma),

Ri is hydrogen, alkyl having 1 to 24 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, cycloalkyl having 5 to 8 carbon atoms or a radical of the formula

R,

-C n H 2n+1 ^-M 1n in which

R 4 and R 5 independently of one another are alkyl having in each case 1 to 5 carbon atoms, or R 4 , together with the radical C n H 2n +i- m , forms a cycloalkyl radical having 5 to 12 carbon atoms, m is 1 or 2, n is an integer from 2 to 20 and

M is a radical of the formula -COOR 6 in which

R 6 is hydrogen, alkyl having 1 to 12 carbon atoms, alkoxyalkyl having in each case 1 to 20 carbon atoms in the alkyl moiety and in the alkoxy moiety or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety,

R 2 is hydrogen, halogen, alkyl having 1 to 18 carbon atoms, and phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, and

R 3 is hydrogen, chlorine, alkyl or alkoxy having in each case 1 to 4 carbon atoms or -COOR 6 in which R 6 is as defined above, at least one of the radicals Ri and R 2 being other than hydrogen;

in the compounds of the formula (Mb) T is hydrogen or alkyl having 1 to 6 carbon atoms, T 1 is hydrogen, chlorine or alkyl or alkoxy having in each case 1 to 4 carbon atoms, n is 1 or 2 and, if n is 1 ,

T 2 is chlorine or a radical of the formula -OT 3 or — N and,

T 5

if n is 2, T 2 is a radical of the formula or -0-Tg-O-; in which

T 3 is hydrogen, alkyl which has 1 to 18 carbon atoms and is unsubstituted or substituted by 1 to 3 hydroxyl groups or by -OCOT 6 , alkyl which has 3 to 18 carbon atoms, is interrupted once or several times by -O- or -NT 6 - and is unsubstituted or substituted by hydroxyl or -OCOT 6 , cycloalkyl which has 5 to 12 carbon atoms and is unsubstituted or substituted by hydroxyl and/or alkyl having 1 to 4 carbon atoms, alkenyl which has 2 to 18 carbon atoms and is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl

moiety, or a radical of the formula -CH 2 CH(OH)-T 7 or , T 4 and T 5 independently of one another are hydrogen, alkyl having 1 to 18 carbon atoms, alkyl which has 3 to 18 carbon atoms and is interrupted once or several times by -O- or -NT 6 -, cycloalkyl having 5 to 12 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety or hydroxyalkyl having 2 to 4 carbon atoms, T 6 is hydrogen, alkyl having 1 to 18 carbon atoms, cycloalkyl having 5 to 12 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, T 7 is hydrogen, alkyl having 1 to 18 carbon atoms, phenyl which is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, or - CH 2 OT 8 ,

T 8 is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 8 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, Tg is alkylene having 2 to 8 carbon atoms, alkenylene having 4 to 8 carbon atoms, alkynylene having 4 carbon atoms, cyclohexylene, alkylene which has 2 to 8 carbon atoms and is interrupted once or several times by -0-, or a radical of the formula - CH 2 CH(OH)CH 2 OT 11 OCH 2 CH(OH)CH 2 - or -CH 2 -C(CH 2 OH) 2 -CH 2 -,

T 10 is alkylene which has 2 to 20 carbon atoms and can be interrupted once or several times by -0-, or cyclohexylene,

T 11 is alkylene having 2 to 8 carbon atoms, alkylene which has 2 to 18 carbon atoms and is interrupted once or several times by -O-, 1 ,3-cyclohexylene, 1 ,4-cyclohexylene, 1 ,3- phenylene or 1 ,4-phenylene, or

T 10 and T 6 , together with the two nitrogen atoms, are a piperazine ring;

in the compounds of formula (lie)

R' 2 is CrC"i 2 alkyl and k is a number from 1 to 4;

in the compounds of the formula (III) u is 1 or 2 and r is an integer from 1 to 3, the substituents

Y 1 independently of one another are hydrogen, hydroxyl, phenyl or halogen, halogenomethyl, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 18 carbon atoms, alkoxy having 1 to 18 carbon atoms which is substituted by a group -COO(CrC-i 8 alkyl); if u is 1 , Y 2 is alkyl having 1 to 18 carbon atoms, phenyl which is unsubstituted or substituted by hydroxyl, halogen, alkyl or alkoxy having 1 to 18 carbon atoms; alkyl which has 1 to 12 carbon atoms and is substituted by -COOH, -COOY 8 , -CONH 2 , - CONHY 9 , -CONY 9 Y 10 , -NH 2 , -NHY 9 , -NY 9 Y 10 , -NHCOY 11 , -CN and/or -OCOY 11 ; alkyl which has 4 to 20 carbon atoms, is interrupted by one or more oxygen atoms and is unsubstituted or substituted by hydroxyl or alkoxy having 1 to 12 carbon atoms, alkenyl having 3 to 6 carbon atoms, glycidyl, cyclohexyl which is unsubstituted or substituted by hydroxyl, alkyl having 1 to 4 carbon atoms and/or -OCOY 11 , phenylalkyl which has 1 to 5 carbon atoms in the alkyl moiety and is unsubstituted or substituted by hydroxyl, chlorine and/or methyl, -COY 12 or -SO 2 Y 13 , or, if u is 2,

Y 2 is alkylene having 2 to 16 carbon atoms, alkenylene having 4 to 12 carbon atoms, xylylene, alkylene which has 3 to 20 carbon atoms, is interrupted by one or more -O- atoms and/or is substituted by hydroxyl, -CH 2 CH(OH)CH 2 -O-Y 15 -OCH 2 CH(OH)CH 2 , -CO-Y 16 -CO-, - CO-NH-Y 17 -NH-CO- or -(CH 2 ) m -CO 2 -Y 18 -OCO-(CH 2 ) m , in which m is 1 , 2 or 3,

Y 8 is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 18 carbon atoms, alkyl which has 3 to 20 carbon atoms, is interrupted by one or more oxygen or sulfur atoms or -NT 6 - and/or is substituted by hydroxyl, alkyl which has 1 to 4 carbon atoms and is substituted by - P(O)(OY 14 ) 2 , -NY 9 Y 10 or -OCOY 11 and/or hydroxyl, alkenyl having 3 to 18 carbon atoms,

glycidyl, or phenylalkyl having 1 to 5 carbon atoms in the alkyl moiety,

Yg and Y-io independently of one another are alkyl having 1 to 12 carbon atoms, alkoxyalkyl having 3 to 12 carbon atoms, dialkylaminoalkyl having 4 to 16 carbon atoms or cyclohexyl having 5 to 12 carbon atoms, or Yg and Y-io together are alkylene, oxaalkylene or azaalkylene having in each case 3 to 9 carbon atoms,

Yii is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms or phenyl,

Y- I2 is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms, phenyl, alkoxy having 1 to 12 carbon atoms, phenoxy, alkylamino having 1 to 12 carbon atoms or phenylamino, Yi 3 is alkyl having 1 to 18 carbon atoms, phenyl or alkylphenyl having 1 to 8 carbon atoms in the alkyl radical,

Yi 4 is alkyl having 1 to 12 carbon atoms or phenyl,

Y 15 is alkylene having 2 to 10 carbon atoms, phenylene or a group -phenylene-M-phenylene- in which M is -O-, -S-, -SO 2 -, -CH 2 - or -C(CH 3 ) 2 -, Y- I 6 is alkylene, oxaalkylene or thiaalkylene having in each case 2 to 10 carbon atoms, phenylene or alkenylene having 2 to 6 carbon atoms,

Y- I 7 is alkylene having 2 to 10 carbon atoms, phenylene or alkylphenylene having 1 to 1 1 carbon atoms in the alkyl moiety, and

Y- I 8 is alkylene having 2 to 10 carbon atoms or alkylene which has 4 to 20 carbon atoms and is interrupted once or several times by oxygen; in the compounds of the formula (IV) x is an integer from 1 to 3 and the substituents L independently of one another are hydrogen, alkyl, alkoxy or alkylthio having in each case 1 to

22 carbon atoms, phenoxy or phenylthio.

7. A method according to claim 1 wherein the coating is solvent based or water based and contains a binder, which is selected from the group consisting of alkyd resins, modified alkyd resins, alkyd urethane resins, alkyd silicone resins, autocrosslinking or non-autocrosslinking acrylic resins, polyester resins, drying oils, phenolic resins and nitrocellulose or mixtures thereof.

8. A method according to claim 7 wherein the coating is water based and contains an acrylic or methacrylic resin.

9. A method according to claim 1 wherein the amount of organic UV-absorber is from 0.5% to 5% by weight based on the weight of the total binder formulation.

10. A method according to claim 1 wherein the amount of inorganic UV-absorber is from 0.002% to 0.5% by weight based on the weight of the total binder formulation.

11. A method according to claim 1 wherein the coating an additional stabilizer selected from the group consisting of a sterically hindered amine light stabilizer, a phosphite or phosphonite and sterically hindered phenolic antioxidant or mixtures thereof.

12. A method according to claim 1 wherein the cork or wood substrate has been pretreated with an aqueous and/or organic solution of bb) bis(1 -oxyl-2,2-6-6-tetramethylpiperidin-4-yl) sebacate; cc) bis(1-hydroxy-2,2-6-6-tetramethylpiperidin-4-yl) sebacate; dd) 1-hydroxy-2,2-6-6-tetramethyl-4-acetoxypiperidinium citrate; ee) 1 -oxyl-2,2,6,6-tetramethyl-4-acetamidopiperidine; ff) 1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidine; gg) 1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium bisulfate; hh) 1 -oxyl-2,2,6,6-tetramethyl-4-oxo-piperidine; ii) 1-hydroxy -2,2,6,6-tetramethyl-4-oxo-piperidine; jj) 1 -hydroxy -2,2,6,6-tetramethyl-4-oxo-piperidinium acetate; kk) 1 -oxyl-2,2,6,6-tetramethyl-4-methoxy-piperidine;

II) 1 -hydroxy-2,2,6,6-tetramethyl-4-methoxy-piperidine; mm) 1 -hydroxyl-2,2,6,6-tetramethyl-4-methoxy-piperidinium acetate; nn) 1-oxyl-2,2,6,6-tetramethyl-4-acetoxypiperidine; oo) 1 -hydroxy-2,2,6,6-tetramethyl-4-acetoxypiperidine; pp) 1 -oxyl-2,2,6,6-tetramethyl-4-propoxy-piperidine; qq) 1 -hydroxy-2,2,6,6-tetramethyl-4-propoxy-piperidinium acetate; rr) 1 -hydroxy-2,2,6,6-tetramethyl-4-propoxy-piperidine; ss) 1 -oxyl-2,2,6,6-tetramethyl-4-(2-hydroxy-4-oxapentoxy)piperidine; tt) 1 -hydroxy-2,2,6,6-tetramethyl-4-(2-hydroxy-4-oxapentoxy)piperidinium acetate; uu) 1 -oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine; vv) 1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidine; ww) 1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium chloride;

xx) 1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium acetate;

W) 1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium bisulfate; zz) 1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium citrate; aaa) bis(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) citrate; bbb) tris(1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) citrate. bb) tetra(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) ethylenediaminetetraacetate;

(cc) tetra(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) ethylenediaminetetraacetate; (dd) tetra(1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) ethylenediaminetetraacetate;

(ee) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) diethylenetriamine- pentaacetate;

(ff) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) diethylenetriamine- pentaacetate;

(gg) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) diethylenetriaminepenta- acetate;

(hh) tri(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) nitrilotriacetate;

(ii) tri(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) nitrilotriacetate; (jj) tri(1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) nitrilotriacetate;

(kk) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) diethylenetriamine- pentamethylenephosphonate;

(II) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) diethylenetriamine- pentamethylenephosphonate; (mm) penta(1-hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) diethylenetriamine- pentamethylenephosphonate or mixtures thereof.

13. A method according to claim 12 wherein the cork or wood substrate has been pretreated with an aqueous and/or organic solution of 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine.

14. Use of a combination of an organic UV-absorber selected from the group consisting of the hydroxybenzophenone, hydroxyphenylbenzotriazole, oxanilide and hydroxyphenyltriazine UV-absorbers or mixtures thereof; and an inorganic UV-absorber selected from the group

consisting of transparent iron oxide, transparent titanium dioxide, transparent zinc oxide, transparent cerium oxide and carbon black or mixtures thereof; in a weight ratio of organic UV-absorber to inorganic UV-absorber from 1000:1 to 10:1 for protecting cork or wood substrates from discoloration wherein the wood substrate is selected from the group consisting of beech, alder, meranti, oak, cherry, teak, nut redwood, mahogany, eucalyptus, american beech, durian, red cedar, leichhardt tree, champa, rubberwood, taiwan ash, campher tree, zebra wood, makha, rosewood, rain tree and ironwood.

Description:

Color Stabilization of Cork and Colored Woods by the Combined Use of Inorganic and Organic UV-Absorbers

The instant invention relates to a method for the color stabilization of cork and specific dark woods by the combined use of a small amount of inorganic UV-absorbers and an excess of organic UV-absorbers in a protective coating. A further aspect of the invention is the use of such a UV-absorber combination for the color stabilization of cork and specific colored woods.

For example cork panels are typically used in kitchens and bathrooms for flooring. They are typically covered by coatings to protect them from humidity, mechanical impacts and light.

These colored cork specimens are very sensitive to UV and visible light. Light causes a bleaching of the initial coloration, resulting in an unwished whitish/grayish appearance. This effect is also known for other colored or dark wood species, such as beech, alder, meranti, oak, cherry, teak, nut, redwood, mahogany, eucalyptus, american beech, durian, red cedar, leichhardt tree, champa, rubberwood, taiwan ash, campher tree, zebra wood, makha, rosewood, rain tree and ironwood.

The problem can not be solved by the single use of organic UV absorbers, such as benzophenone, benzotriazole or triazine UV absorbers which protect only in the UV-A and UV-B region. The visible light still bleaches the natural colorants in the cork/wood species.

UV absorbers for the visible area, which screen a part of the visible light, are in general pigments. However, when pigments are used alone they have to be used in an effective amount and thereby impart their inherent color and opacity to the coating.

WO 2005/0051 14 suggests a pretreatment of wood in general with specific hydroxy or nitroxy groups containing tetramethylpiperidines and applying then a coating over the wood panels, which contains transparent inorganic oxides. However the amounts of transparent oxides needed are too high and impart an undesired color to the substrate. Cork and specific dark wood species are not mentioned.

The present invention provides a solution for this problem. It has been found that combinations of organic UV-Absorbers and small amounts of transparent inorganic oxides, such as iron oxides, micronized titanium dioxide, zinc oxide, cerium oxide or carbon black

show synergistic effects in terms of color stabilization after light exposure without essentially affecting the initial color.

One aspect of the instant invention is a method for protecting cork or wood substrates from discoloration wherein the wood substrate is selected from the group consisting of beech, alder, meranti, oak, cherry, teak, nut, redwood, mahogany, eucalyptus, american beech, durian, red cedar, leichhardt tree, champa, rubberwood, taiwan ash, campher tree, zebra wood, makha, rosewood, rain tree and ironwood; comprising, applying to the cork or wood substrate a coating, which coating contains

a) an organic UV-absorber selected from the group consisting of the hydroxybenzophenone, hydroxyphenylbenzotriazole, oxanilide and hydroxyphenyltriazine UV-absorbers or mixtures thereof; and

b) an inorganic UV-absorber selected from the group consisting of transparent iron oxide, transparent titanium dioxide, transparent zinc oxide, transparent cerium oxide and carbon black or mixtures thereof; wherein the weight ratio of organic UV-absorber to inorganic UV-absorber is from 1000:1 to 10:1.

For instance the substrate is selected from the group consisting of beech, alder, meranti, oak, cherry, teak, nut redwood and mahogany.

For example the substrate is cork or alder.

Preferably the substrate is cork.

Typically the substrate is in the form of a panel or board, which is used in indoor applications, such as flooring. It is, however, also possible to use it in outdoor applications.

Preferably the inorganic UV-absorber is a transparent iron oxide or carbon black or a mixture thereof.

The inorganic pigments may be present, for example, in the form of nano-particles.

The iron oxides typically have a yellow, red or brown shade. The crystal forms are typically of goethite, hematite structure or mixtures thereof. The particle size is typically 50-100 nm in length, 10-20 nm wide and 2-5 nm thick. The specific surfaces measured according to BET are usually higher than 60 m 2 / g.

Alternatively titaniumdioxide may be used, preferably as rutile structure.

In general iron oxides are preferred.

The transparent inorganic pigments are items of commerce. They are produced and sold for example under the trade name Sicotrans® by BASF, under the trade name Hombitec RM® by Sachtleben, under the Tradename Rhodigard® W 200, Rhodigard® S 100 by Rhodia and under the trade name ZinClear® by Advanced Powder Technology Pty Ltd.

Preferred is a method wherein the hydroxybenzophenone is of formula I

the 2-hydroxyphenylbenzotriazole is of formula Na, Mb or Nc

(lie) ;

- A -

the 2-hydroxyphenyltriazine is of formula

and the oxanilide is of formula (IV)

(IV) ; wherein

in the compounds of the formula (I) v is an integer from 1 to 3 and w is 1 or 2 and the substituents Z independently of one another are hydrogen, halogen, hydroxyl or alkoxy having 1 to 12 carbon atoms;

in the compounds of the formula (Ma),

Ri is hydrogen, alkyl having 1 to 24 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, cycloalkyl having 5 to 8 carbon atoms or a radical of the formula

R,

-C n H 2n+1 ^ 1 -M n , in which

R 4 and R 5 independently of one another are alkyl having in each case 1 to 5 carbon atoms, or R 4 , together with the radical C n H 2n +i- m , forms a cycloalkyl radical having 5 to 12 carbon atoms, m is 1 or 2, n is an integer from 2 to 20 and

M is a radical of the formula -COORβ in which

R 6 is hydrogen, alkyl having 1 to 12 carbon atoms, alkoxyalkyl having in each case 1 to 20 carbon atoms in the alkyl moiety and in the alkoxy moiety or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety,

R 2 is hydrogen, halogen, alkyl having 1 to 18 carbon atoms, and phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, and

R 3 is hydrogen, chlorine, alkyl or alkoxy having in each case 1 to 4 carbon atoms or -COOR 6 in which R 6 is as defined above, at least one of the radicals Ri and R 2 being other than hydrogen;

in the compounds of the formula (Mb)

T is hydrogen or alkyl having 1 to 6 carbon atoms,

T 1 is hydrogen, chlorine or alkyl or alkoxy having in each case 1 to 4 carbon atoms, n is 1 or 2 and, if n is 1 ,

T 2 is chlorine or a radical of the formula -OT 3 or — N N ^ and,

if n is 2, T 2 is a radical of the formula or -0-T 9 -O-; in which

T 3 is hydrogen, alkyl which has 1 to 18 carbon atoms and is unsubstituted or substituted by 1 to 3 hydroxyl groups or by -OCOT 6 , alkyl which has 3 to 18 carbon atoms, is interrupted once or several times by -O- or -NT 6 - and is unsubstituted or substituted by hydroxyl or -OCOT 6 , cycloalkyl which has 5 to 12 carbon atoms and is unsubstituted or substituted by hydroxyl and/or alkyl having 1 to 4 carbon atoms, alkenyl which has 2 to 18 carbon atoms and is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl

moiety, or a radical of the formula -CH 2 CH(OH)-T 7 or , T 4 and T 5 independently of one another are hydrogen, alkyl having 1 to 18 carbon atoms, alkyl which has 3 to 18 carbon atoms and is interrupted once or several times by -O- or -NT 6 -, cycloalkyl having 5 to 12 carbon atoms, phenyl, phenyl which is substituted by alkyl

having 1 to 4 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety or hydroxyalkyl having 2 to 4 carbon atoms, T 6 is hydrogen, alkyl having 1 to 18 carbon atoms, cycloalkyl having 5 to 12 carbon atoms, alkenyl having 3 to 8 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety,

T 7 is hydrogen, alkyl having 1 to 18 carbon atoms, phenyl which is unsubstituted or substituted by hydroxyl, phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, or -

CH 2 OT 8 ,

T 8 is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 8 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, phenyl, phenyl which is substituted by alkyl having 1 to 4 carbon atoms, or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety,

Tg is alkylene having 2 to 8 carbon atoms, alkenylene having 4 to 8 carbon atoms, alkynylene having 4 carbon atoms, cyclohexylene, alkylene which has 2 to 8 carbon atoms and is interrupted once or several times by -O-, or a radical of the formula - CH 2 CH(OH)CH 2 OT 11 OCH 2 CH(OH)CH 2 - or -CH 2 -C(CH 2 OH) 2 -CH 2 -,

T 10 is alkylene which has 2 to 20 carbon atoms and can be interrupted once or several times by -O-, or cyclohexylene,

T 11 is alkylene having 2 to 8 carbon atoms, alkylene which has 2 to 18 carbon atoms and is interrupted once or several times by -O-, 1 ,3-cyclohexylene, 1 ,4-cyclohexylene, 1 ,3- phenylene or 1 ,4-phenylene, or

T 10 and T 6 , together with the two nitrogen atoms, are a piperazine ring;

in the compounds of formula (lie)

R' 2 is C-ι-C 12 alkyl and k is a number from 1 to 4;

in the compounds of the formula (III) u is 1 or 2 and r is an integer from 1 to 3, the substituents

Y 1 independently of one another are hydrogen, hydroxyl, phenyl or halogen, halogenomethyl, alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 18 carbon atoms, alkoxy having 1 to 18 carbon atoms which is substituted by a group -COO(C-ι-C 18 alkyl); if u is 1 ,

Y 2 is alkyl having 1 to 18 carbon atoms, phenyl which is unsubstituted or substituted by hydroxyl, halogen, alkyl or alkoxy having 1 to 18 carbon atoms; alkyl which has 1 to 12 carbon atoms and is substituted by -COOH, -COOY 8 , -CONH 2 , -

CONHY 9 , -CONY 9 Y 10 , -NH 2 , -NHY 9 , -NY 9 Y 10 , -NHCOY 11 , -CN and/or -OCOY 11 ; alkyl which has 4 to 20 carbon atoms, is interrupted by one or more oxygen atoms and is unsubstituted or substituted by hydroxyl or alkoxy having 1 to 12 carbon atoms, alkenyl having 3 to 6 carbon atoms, glycidyl, cyclohexyl which is unsubstituted or substituted by hydroxyl, alkyl having 1 to 4 carbon atoms and/or -OCOY 11 , phenylalkyl which has 1 to 5 carbon atoms in the alkyl moiety and is unsubstituted or substituted by hydroxyl, chlorine and/or methyl, -COY 12 or -SO 2 Y 13 , or, if u is 2,

Y 2 is alkylene having 2 to 16 carbon atoms, alkenylene having 4 to 12 carbon atoms, xylylene, alkylene which has 3 to 20 carbon atoms, is interrupted by one or more -O- atoms and/or is substituted by hydroxyl, -CH 2 CH(OH)CH 2 -O-Y 15 -OCH 2 CH(OH)CH 2 , -CO-Y 16 -CO-, -

CO-NH-Y 17 -NH-CO- or -(CH 2 ) m -CO 2 -Y 18 -OCO-(CH 2 ) m , in which m is 1 , 2 or 3,

Y 8 is alkyl having 1 to 18 carbon atoms, alkenyl having 3 to 18 carbon atoms, alkyl which has 3 to 20 carbon atoms, is interrupted by one or more oxygen or sulfur atoms or -NT 6 - and/or is substituted by hydroxyl, alkyl which has 1 to 4 carbon atoms and is substituted by -

P(O)(OY 14 ) 2 , -NY 9 Y 10 or -OCOY 11 and/or hydroxyl, alkenyl having 3 to 18 carbon atoms, glycidyl, or phenylalkyl having 1 to 5 carbon atoms in the alkyl moiety,

Y 9 and Y 10 independently of one another are alkyl having 1 to 12 carbon atoms, alkoxyalkyl having 3 to 12 carbon atoms, dialkylaminoalkyl having 4 to 16 carbon atoms or cyclohexyl having 5 to 12 carbon atoms, or Y 9 and Y 10 together are alkylene, oxaalkylene or azaalkylene having in each case 3 to 9 carbon atoms,

Y 11 is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms or phenyl,

Y 12 is alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 18 carbon atoms, phenyl, alkoxy having 1 to 12 carbon atoms, phenoxy, alkylamino having 1 to 12 carbon atoms or phenylamino,

Y 13 is alkyl having 1 to 18 carbon atoms, phenyl or alkylphenyl having 1 to 8 carbon atoms in the alkyl radical,

Y 14 is alkyl having 1 to 12 carbon atoms or phenyl, Y 15 is alkylene having 2 to 10 carbon atoms, phenylene or a group -phenylene-M-phenylene- in which M is -0-, -S-, -SO 2 -, -CH 2 - or -C(CH 3 ) 2 -,

Y 16 is alkylene, oxaalkylene or thiaalkylene having in each case 2 to 10 carbon atoms, phenylene or alkenylene having 2 to 6 carbon atoms,

Y 17 is alkylene having 2 to 10 carbon atoms, phenylene or alkylphenylene having 1 to 11

carbon atoms in the alkyl moiety, and

Y- 1 8 is alkylene having 2 to 10 carbon atoms or alkylene which has 4 to 20 carbon atoms and is interrupted once or several times by oxygen;

in the compounds of the formula (IV) x is an integer from 1 to 3 and the substituents L independently of one another are hydrogen, alkyl, alkoxy or alkylthio having in each case 1 to 22 carbon atoms, phenoxy or phenylthio.

d-Ciβalkyl may be linear or branched. Examples of alkyl having up to 18 carbon atoms 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-methylhexyl, n-heptyl, isoheptyl, 1 ,1 ,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethylhexyl, 1 ,1 ,3-trimethyl- hexyl, 1 ,1 ,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl, 1 ,1 ,3,3,5,5- hexamethylhexyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl.

In the compounds of the formula (Ma) Ri can be hydrogen or alkyl having 1 to 24 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl, octyl, nonyl, dodecyl, tetradecyl, hexadecyl, octadecyl, nonadecyl and eicosyl and also corresponding branched isomers. Furthermore, in addition to phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, for example benzyl, R 1 can also be cycloalkyl having 5 to 8 carbon atoms, for example

cyclopentyl, cyclohexyl and cyclooctyl, or a radical of the formula in

"C n H 2n + 1 -rn- M m

5 which R 4 and R 5 independently of one another are alkyl having in each case 1 to 5 carbon atoms, in particular methyl, or R 4 , together with the C n H 2n +i- m radical, forms a cycloalkyl radical having 5 to 12 carbon atoms, for example cyclohexyl, cyclooctyl and cyclodecyl. M is a radical of the formula -COOR 6 in which R 6 is not only hydrogen but also alkyl having 1 to 12 carbon atoms or alkoxyalkyl having 1 to 20 carbon atoms in each of the alkyl and alkoxy moieties. Suitable alkyl radicals R 6 are those enumerated for R 1 . Examples of suitable alkoxyalkyl groups are -CaH 4 OCaH 5 , -CaH 4 OCeH 17 and -C 4 H 8 OC 4 Hg. As phenylalkyl having 1 to 4 carbon atoms, R 6 is, for example, benzyl, cumyl, α-methylbenzyl or phenylbutyl.

In addition to hydrogen and halogen, for example chlorine and bromine, R 2 can also be alkyl having 1 to 18 carbon atoms. Examples of such alkyl radicals are indicated in the definitions

of Ri. R 2 can also be phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety, for example benzyl, a-methylbenzyl and cumyl.

Halogen as a substituent means in all cases fluorine, chlorine, bromine or iodine, preferably chlorine or bromine and more preferably chlorine.

At least one of the radicals Ri and R 2 must be other than hydrogen.

In addition to hydrogen or chlorine, R 3 is also alkyl or alkoxy having in each case 1 to 4 carbon atoms, for example methyl, butyl, methoxy and ethoxy, and also -COOR 6 .

In the compounds of the formula (Mb) T is hydrogen or alkyl having 1 to 6 carbon atoms, such as methyl and butyl, T 1 is not only hydrogen or chlorine, but also alkyl or alkoxy having in each case 1 to 4 carbon atoms, for example methyl, methoxy and butoxy, and, if n is 1 , T 2 is chlorine or a radical of the formula -OT 3 or -NT 4 T 5 . T 3 is here hydrogen or alkyl having 1 to 18 carbon atoms (cf. the definition of Ri). These alkyl radicals can be substituted by 1 to 3 hydroxyl groups or by a radical -OCOT 6 . Furthermore, T 3 can be alkyl having 3 to 18 carbon atoms (cf. the definition of Ri) which is interrupted once or several times by -O- or -NT 6 - and is unsubstituted or substituted by hydroxyl or -OCOT 6 . Examples of T 3 as cycloalkyl are cyclopentyl, cyclohexyl or cyclooctyl. T 3 can also be alkenyl having 2 to 18 carbon atoms. Suitable alkenyl radicals are derived from the alkyl radicals enumerated in the definitions of R 1 . These alkenyl radicals can be substituted by hydroxyl. Examples of T 3 as phenylalkyl are benzyl, phenylethyl, cumyl, α-methylbenzyl or benzyl. T 3 can also be a radical of the formula

Like T 3 , T 4 and T 5 can, independently of one another, be not only hydrogen but also alkyl having 1 to 18 carbon atoms or alkyl which has 3 to 18 carbon atoms and is interrupted once or several times by -O- or -NT 6 -. T 4 and T 5 can also be cycloalkyl having 5 to 12 carbon atoms, for example cyclopentyl, cyclohexyl and cyclooctyl. Examples of T 4 and T 5 as alkenyl groups can be found in the illustrations of T 3 . Examples of T 4 and T 5 as phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety are benzyl or phenylbutyl. Finally, these substituents can also be hydroxyalkyl having 1 to 3 carbon atoms.

If n is 2, T 2 is a divalent radical of the formula / 10 \ or -0-Tg-O-.

In addition to hydrogen, T 6 (see above also) is alkyl, cycloalkyl, alkenyl, aryl or phenylalkyl; examples of such radicals have already been given above.

In addition to hydrogen and the phenylalkyl radicals and long-chain alkyl radicals mentioned above, T 7 can be phenyl or hydroxyphenyl and also -CH 2 OT 8 in which T 8 can be one of the alkyl, alkenyl, cycloalkyl, aryl or phenylalkyl radicals enumerated.

The divalent radical Tg can be alkylene having 2 to 8 carbon atoms, and such radicals can also be branched. This also applies to the alkenylene and alkynylene radicals Tg. As well as cyclohexylene, Tg can also be a radical of the formula CH 2 CH(OH)CH 2 OT 11 OCH 2 CH(OH)CH 2 - or -CH 2 -C(CH 2 OH) 2 -CH 2 -.

T 10 is a divalent radical and, in addition to cyclohexylene, is also alkylene which has 2 to 20 carbon atoms and which can be interrupted once or several times by -O-. Suitable alkylene radicals are derived from the alkyl radicals mentioned in the definitions of R 1 .

T 11 is also an alkylene radical. It contains 2 to 8 carbon atoms or, if it is interrupted once or several times by -O-, 4 to 10 carbon atoms. T 11 is also 1 ,3-cyclohexylene, 1 ,4-cyclohexylene, 1 ,3-phenylene or 1 ,4-phenylene.

Together with the two nitrogen atoms, T 6 and T 10 can also be a piperazine ring.

Examples of alkyl, alkoxy, phenylalkyl, alkylene, alkenylene, alkoxyalkyl and cycloalkyl radicals and also alkylthio, oxaalkylene or azoalkylene radicals in the compounds of the formulae (I), (Na), (Mb), (lie), (III) and IV) can be deduced from the above statements.

Within the benzotriazole UV-absorbers those according to formula Ma are in general preferred.

The UV absorbers of the formulae (I), (Ma), (lib), (lie), (III) and (IV) are known per se and are described, together with their preparation in, for example, WO 96/28431 , EP-A-323 408, EP- A-57 160, US 5 736 597 (EP-A-434 608), US 4 619 956, DE-A 31 35 810 and GB-A 1 336 391. Preferred meanings of substituents and individual compounds can be deduced from the documents mentioned.

In another embodiment the UV-absorbers of the class of hydroxyphenyl triazines are of formula (Ilia)

in which n is 1 or 2;

R 301 , R 1 Jj01 , R 302 and R' 3O2 , independently of one another, are H, OH, C r C 12 alkyl; C 2 -

C 6 alkenyl; C^C^alkoxy; C 2 -C 18 alkenoxy; halogen; trifluoromethyl; C^C^phenylalkyl; phenyl; phenyl which is substituted by C -C alkyl, C^C^alkoxy or halogen; phenoxy; or phenoxy which is substituted by C^C^alkyl, C^C^alkoxy or halogen;

R 303 and R 304 , independently of one another, are H, C^C^alkyl; OR' 307 ; C 2 -C 6 alkenyl; C 2 - C 18 alkenoxy; halogen; trifluoromethyl; C^C^phenylalkyl; phenyl; phenyl which is substituted by C -C alkyl, C^C^alkoxy or halogen; phenoxy; or phenoxy which is substituted by C 1 - C 18 alkyl, C 1 -C^aIkOXy or halogen;

R 306 is hydrogen, C^C^alkyl, C 5 -C 12 cycloalkyl or C 7 -C 15 phenylalkyl;

R, , in the case where n = 1 , and R' , independently of one another, are hydrogen or C -

C 18 alkyl; or are C -C alkyl which is substituted by OH, C^C^alkoxy, allyloxy, halogen, -

COOH, -COOR 308 , -CONH 2 , -CONHR 309 , -CON(R 309 )(R 310 ), -NH 2 , -NHR 309 , -N(R 309 )(R 310 ), - NHCOR,.., -CN, -OCOR,.., phenoxy and/or phenoxy which is substituted by C.-C. a alkyl, C 1 -

C 18 alkoxy or halogen; or R 307 is C 3 -C 50 alkyl which is interrupted by -O- and may be substituted by OH; or R / is C0 -C0.alkenyl; glycidyl; C o -C 1.2x. ycloalkyl which is substituted by

OH, C 1 -C 4 SIkYl Or -OCOR 311 ; C^C^phenylalkyl which is unsubstituted or substituted by OH, Cl or CH 3 ; -CO-R 312 or -SO 2 -R 313 ;

R, n- ,, in the case where n = 2, is C -C..alkylene, C -C..alkenylene, xylylene, C -C. n alkylene which is interrupted by O and/or substituted by OH, or is a group of the formula - CH 2 CH(OH)CH 2 O-R 320 -OCH 2 CH(OH)CH 2 -, -CO-R 321 -CO-, -CO-NH-R 322 -NH-CO- or -(CH 2 ) m - COO-R 323 -OOC-(CH 2 ) m -, in which m is a number in the range from 1 to 3, or is

R qna is C.-C. Q alkyl; C -C, Q alkenyl; hydroxyethyl; C -C κ- alkyl which is interrupted by O, NH,

NR 309 or S and/or is substituted by OH; C r C 4 alkyl which is substituted by -P(O)(OR 314 ) 2 , - N(R 309 )(R 310 ) Or -OCOR 311 and/or OH; glycidyl; C 5 -C 12 cycloalkyl; phenyl; C 7 -C 14 alkylphenyl or C y -C^phenylalkyl; R, o m uy and R, o, i n u, independently of one another, are C i-C. i -._.alkyl; C o -C. i -._.alkoxyalkyl; C T--

C. 10-dialkylaminoalkyl or C o -C. i -x_. ycloalkyl, or R ouy and R, o, i n u together are C o -C y.alkylene or - oxaalkylene or -azaalkylene;

R,.. is C -C..alkyl; C -C..alkenyl or phenyl; C -C..hydroxyalkyl; cyclohexyl; or is C -C ^ alkyl which is interrupted by -O- and may be substituted by OH; R 312 is C r C 18 alkyl; C 2 -C alkenyl; phenyl; C r C alkoxy; C 3 -C 18 alkenyloxy; C 3 -C 5Q alkoxy which is interrupted by O, NH, NR Qnn or S and/or substituted by OH; cyclohexyloxy; C - C 14 alkylphenoxy; C^C^phenylalkoxy; phenoxy; C^C^alkylamino; phenylamino; tolylamino or naphthylamino; R,., is C -C..alkyl; phenyl; naphthyl or C -C..alkylphenyl; R 314 is C^C^alkyl, methylphenyl or phenyl;

R,. n is C -C. n alkylene; C -C ^ alkylene which is interrupted by O, phenylene or a -phenylene-

X-phenylene- group, in which X is -0-, -S-, -SO -, -CH - or -C(CHJ -;

R,.. is C -C. n alkylene, C -C.xxaalkylene, C -C. n thiaalkylene, C -C..arylene or C - C alkenylene;

R 322 is C 2 -C 10 alkylene, phenylene, tolylene, diphenylenemethane or a CH 2 -

group; and

R... is C -C, n alkylene or C -C_ n alkylene which is interrupted by O.

Halogen is in all cases fluorine, chlorine, bromine or iodine.

Examples of alkyl 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-methylhexyl, n- heptyl, isoheptyl, 1 ,1 ,3,3-tetramethylbutyl, 1-methylheptyl, 3-methylheptyl, n-octyl, 2-ethyl- hexyl, 1 ,1 ,3-trimethylhexyl, 1 ,1 ,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1-methylundecyl, dodecyl.

Examples of alkoxy having up to 12 carbon atoms are methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy, octoxy, decyloxy, dodecyloxy.

Examples of alkenoxy are propenyloxy, butenyloxy, pentenyloxy and hexenyloxy.

Examples of C 5 -Ci 2 cycloalkyl are cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl and cyclo- dodecyl. C 5 -C 8 Cycloalkyl, especially cyclohexyl, is preferred.

C 1 -C 4 Alkyl-substit.ut.ed C 5 -Ci 2 cycloalkyl is for example methylcyclohexyl or dimethyl- cyclohexyl.

OH- and/or d-C-ioalkyl-substituted phenyl is for example methylphenyl, dimethylphenyl, trimethylphenyl, tert-butylphenyl or 3,5-di-tert-butyl-4-hydroxyphenyl.

Alkoxy-substituted phenyl is for example methoxyphenyl dimethoxyphenyl or trimethoxy- phenyl.

Examples of C 7 -C 9 phenylalkyl are benzyl and phenylethyl.

C 7 -C 9 Phenylalkyl which is substituted on the phenyl radical by -OH and/or by alkyl having up to 10 carbon atoms is for example methylbenzyl, dimethylbenzyl, trimethylbenzyl, tert- butylbenzyl or 3,5-di-tert-butyl-4-hydroxybenzyl.

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

Examples of alkylene are methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, 2,2-dimethyltrimethylene, hexamethylene, trimethylhexamethylene, octa- methylene and decamethylene.

Examples of alkenylene are butenylene, pentenylene and hexenylene.

C 6 -Ci 2 arylene is preferably phenylene.

Alkyl interrupted by O is for example -CH 2 -CH 2 -O-CH 2 -CH 3 , -CH 2 -CH 2 -O-CH 3 - or -CH 2 -CH 2 - 0-CH 2 -CH 2 -CH 2 -O-CH 2 -CH 3 -. It is preferably derived from polyethlene glycol. A general description is -((CH 2 ) a -O) b -H/CH 3 , wherein a is a number from 1 to 6 and b is a number from 2 to 10.

C 2 -CiO oxaalkylene and C 2 -Ciothiaalkylene can be deduced from the above mentioned alkylene groups by substituting one or more carbon atoms by an oxygen atom or a sulphur atom.

Specific examples of 2-hydroxybenzophenones are for example the 4-hydroxy, 4-methoxy, 4- octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy and 2'-hydroxy-4,4'-dimethoxy derivatives.

Specific examples of 2-(2'-hydroxyphenyl)benzotriazoles are for example 2-(2'-hydroxy-5'- methylphenyl)-benzotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)benzotriazole, 2-(5'-tert- butyl-2'-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-(1 ,1 ,3,3-tetramethylbutyl)phenyl)ben- zotriazole, 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-5-chloro-benzotriaz ole, 2-(3'-tert-butyl- 2'- hydroxy-5'-methylphenyl)-5-chloro-benzotriazole, 2-(3'-sec-butyl-5'-tert-butyl-2'-hydroxyphe- nyl)benzotriazole, 2-(2'-hydroxy-4'-octyloxyphenyl)benzotriazole, 2-(3',5'-di-tert-amyl-2'-hy- droxyphenyl)benzotriazole, 2-(3',5'-bis-(α,α-dimethylbenzyl)-2'-hydroxyphenyl)benzotr iazole,

2-(3'-tert-butyl-2'-hydroxy-5'-(2-octyloxycarbonylethyl)p henyl)-5-chloro-benzotriazole, 2-(3'- tert-butyl-5'-[2-(2-ethylhexyloxy)-carbonylethyl]-2'-hydroxy phenyl)-5-chloro-benzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl) -5-chloro-benzotriazole, 2-(3'-tert- butyl-2'-hydroxy-5'-(2-methoxycarbonylethyl)phenyl)benzotria zole, 2-(3'-tert-butyl-2'-hydroxy- 5'-(2-octyloxycarbonylethyl)phenyl)benzotriazole, 2-(3'-tert-butyl-5'-[2-(2-ethylhexyloxy)car- bonylethyl]-2'-hydroxyphenyl)benzotriazole, 2-(3'-dodecyl-2'-hydroxy-5'-methylphenyl)benzo- triazole, 2-(3'-tert-butyl-2'-hydroxy-5'-(2-isooctyloxycarbonylethyl)p henylbenzotriazole, 2,2'- methylene-bis[4-(1 ,1 ,3,3-tetramethylbutyl)-6-benzotriazole-2-ylphenol]; the transesterification product of 2-[3'-tert-butyl-5'-(2-methoxycarbonylethyl)-2'-hydroxypheny l]-2H-benzotriazole

with polyethylene glycol 300; [R-CH 2 CH 2 -COO-CH 2 CH 2 -^- where R = 3'-tert-butyl-4'-

hydroxy-5'-2H-benzotriazol-2-ylphenyl, 2-[2'-hydroxy-3'-(α,α-dimethylbenzyl)-5'-(1 ,1 ,3,3-tetra- methylbutyl)-phenyl]benzotriazole; 2-[2'-hydroxy-3'-(1 ,1 ,3,3-tetramethylbutyl)-5'-(α,α-dime- thylbenzyl)-phenyl]benzotriazole.

Specific examples of 2-(2-hydroxyphenyl)-1 ,3,5-triazines are for example 2,4,6-tris(2- hydroxy-4-octyloxyphenyl)-1 ,3,5-triazine, 2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dime- thylphenyl)-1 ,3,5-triazine, 2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1 ,3,5-triazine, 2,4-bis(2-hydroxy-4-propyloxyphenyl)-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-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/tridecyloxy-2-hydroxypropoxy)-2-hydroxy- phenyl]-4,6-bis(2,4-dimethylphenyl)-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-hydroxy- propyloxy]phenyl}-4,6-bis(2,4-dimethylphenyl)-1 ,3,5-triazine and 2-(2-hydroxy-4-(2-ethyl- hexyl)oxy)phenyl-4,6-di(4-phenyl)phenyl-1 ,3,5-triazine.

For instance the hydroxyphenyl-triazine UV-absorbers are of formulae:

, 3

; GI=CH(CHa)-COO-C 2 H 5 ,

= a mixture of a) R1 = R2 = CH(CHa)-COO-C 8 H 17 , R3= R4 =H; b) R1 = R2 = R3 = CH(CHa)-COO-C 8 H 17 , R4 =H; c) R1 = R2 = R3 = R4 = CH(CH 3 )-COO-C 8 H 17 ,

The hydroxyphenyl triazine UV-absorbers are known and partially items of commerce. They can be prepared according to the above documents.

Specific examples for oxamides are 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.

The above mentioned UV-absorbers are largely items of commerce and for example known as Tinuvin® 109, 171 , 326, 327, 328, 350, 360, 384, 400, 405, 41 1 or Chimassorb® 81 from Ciba Specialty Chemicals or Cyasorb® 1 164 from Cytech Inc.

In many cases it may be of advantage to use a combination of UV-absorbers from different classes, such as for example a benzophenone UV-absorber with a benzotriazole UV- absorber or a hydroxyphenyltriazine UV-absorber with a benzotriazole UV-absorber. If such a combination is used, the weight ratio between both UV-absorbers is for example from 1 :5 to 5:1 , for instanc from 1 :3 to 3:1 , particularly 1 :1.5 to 1.5:1.

When a water based coating is applied the organic UV-absorber is advantageously in the form of concentrated aqueous polymer dispersion with a particle size of less than 1000 nm, prepared by heterophase radical polymerization of ethylenically unsaturated monomers in the presence of the UV-absorber. Such preparations are, for example, described in WO 05/023878.

Principally a variety of coatings may be applied, for example, those listed below:

a) 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.

b) Drying and non-drying alkyd resins.

c) 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.

d) Crosslinkable acrylic resins derived from substituted acrylates, for example epoxy acry- lates, urethane acrylates or polyester acrylates.

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

f) 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.

In principal the coating is solvent based or water based and contains a binder, which is selected from the group consisting of alkyd resins, modified alkyd resins, alkyd urethane resins, alkyd silicone resins, autocrosslinking or non-autocrosslinking acrylic resins, polyester resins, drying oils, phenolic resins and nitrocellulose or mixtures thereof.

Typical examples of organic solvents, which may suitably be used for the coating compositions are aliphatic, aromatic or cycloaliphatic hydrocarbons, alcohols, esters, ketones or chlorinated hydrocarbons.

Water/solvent mixtures are typically mixtures of water and lower alcohols, glycols or glycol ethers.

The coating may also be a radiation-curable, solvent-free formulation of photopolymerisable compounds. Illustrative examples are mixtures of acrylates or methacrylates, unsaturated polyester/styrene mixtures or mixtures of other ethylenically unsaturated monomers or oligomers.

Preferably the coating is water based and contains an acrylic or methacrylic resin.

For example the amount of organic UV-absorber is from 0.5% to 5%, in particular from 0.5% to 3% by weight based on the weight of the total binder formulation.

For instance the amount of inorganic UV-absorber is from 0.002% to 0.5%, in particular from 0.01 to 0.3% by weight based on the weight of the total binder formulation.

The coating can be applied to the cork or wood substrate by conventional techniques, for example by spreading, brushing, dipping, deluging or spraying.

The coating may contain an additional stabilizer selected from the group consisting of a sterically hindered amine light stabilizer, a phosphite or phosphonite and sterically hindered phenolic antioxidant or mixtures thereof. Examples are given below

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 there- of.

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-buty l-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-dodecylmer captobutane, 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.δ-di-tert-butyl^-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)malona te, 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-hydroxybe nzyl)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)isocyanu rate, 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-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, 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-O.δ-dicvclohexyl^-hvdroxyphenvDpropionic 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, tri- ethylene glycol, pentaerythritol, tris(hydroxyethyl)isocyanurate, N,N'-bis(hydroxyethyl)ox- amide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hy- droxymethyl-i-phospha^.θj-trioxabicycloβ^^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-i-phospha^.θj-trioxabicyclolz.^^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]propionylox y)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.

2.1. Sterically hindered amines, for example 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)hexamethylenediamin e 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-tetramethylpiperazinone), 4-benzoyl-2,2,6,6-tetramethylpiperidine, 4-stearyloxy- 2,2,6,6-tetramethylpiperidine, 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 -octyloxy-2,2,6,6-tetramethylpiperidyl)sebacate, bis(1 -octyloxy-2,2,6,6- tetramethylpiperidyl)succinate, linear or cyclic condensates of N,N'-bis(2,2,6,6-tetramethyl-4- piperidyl)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-pentamethylpiperidyl)-1 ,3,5-triazine and 1 ,2-bis(3-aminopropylamino)ethane, 8- acetyl-3-dodecyl-7,7,9,9-tetramethyl-1 ,3,8-triazaspiro[4.5]decane-2,4-dione, 3-dodecyl-1 - (2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-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 7,7,9,9-tetramethyl-2-cycloundecyl-1-oxa-3,8-diaza-4-oxospir o- [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)hex a- methylenediamine, 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-ami- nopiperidine 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-hydr- oxy-2-methylpropoxy)-4-octadecanoyloxy-2,2,6,6-tetramethylpi peridine, 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- [(i-cyclohexyloxy^^.θ.θ-piperidine^-yljbutylaminoj-θ-chlo ro-s-triazine with N,N'-bis(3-ami- nopropyl)ethylenediamine), 1 ,3,5-tris(N-cyclohexyl-N-(2,2,6,6-tetramethylpiperazine-3-on e-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.

3. 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,

(F) H 37 C 11 - -C 1 18 0 H' '37 (G)

In a specific embodiment of the invention the cork or wood substrate has been pretreated with an aqueous and/or organic solution of a) bis(1-oxyl-2,2-6-6-tetramethylpiperidin-4-yl) sebacate; b) bis(1-hydroxy-2,2-6-6-tetramethylpiperidin-4-yl) sebacate; c) 1-hydroxy-2,2-6-6-tetramethyl-4-acetoxypiperidinium citrate; d) 1-oxyl-2,2,6,6-tetramethyl-4-acetamidopiperidine; e) 1 -hydroxy^^.θ.θ-tetramethyM-acetamidopiperidine; f) 1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium bisulfate; g) 1 -oxyl-2,2,6,6-tetramethyl-4-oxo-piperidine; h) 1 -hydroxy -2,2,6,6-tetramethyl-4-oxo-piperidine; i) 1 -hydroxy -2,2,6, 6-tetramethyl-4-oxo-piperidinium acetate; j) 1 -oxyl-2,2,6,6-tetramethyl-4-methoxy-piperidine; k) 1 -hydroxy-2,2,6,6-tetramethyl-4-methoxy-piperidine;

I) 1 -hydroxyl-2,2,6,6-tetramethyl-4-methoxy-piperidinium acetate; m) 1 -oxyl-2,2,6,6-tetramethyl-4-acetoxypiperidine; n) 1-hydroxy-2,2,6,6-tetramethyl-4-acetoxypiperidine; o) 1 -oxyl-2,2,6,6-tetramethyl-4-propoxy-piperidine; p) 1 -hydroxy-2,2,6,6-tetramethyl-4-propoxy-piperidinium acetate; q) 1 -hydroxy-2,2,6,6-tetramethyl-4-propoxy-piperidine; r) 1-oxyl-2,2,6,6-tetramethyl-4-(2-hydroxy-4-oxapentoxy)piperid ine; s) 1-hydroxy-2,2,6,6-tetramethyl-4-(2-hydroxy-4-oxapentoxy)pipe ridinium acetate;

t) 1 -oxyl-2,2,6,6-tetramethyl-4-hydroxypipeιϊdine; u) 1 -hydroxy^^.θ.θ-tetramethyM-hydroxypiperidine; v) 1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium chloride; w) 1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium acetate; x) 1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium bisulfate; y) 1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium citrate; z) bis(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) citrate; aa) tris(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) citrate. bb) tetra(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) ethylenediaminetetraacetate;

(cc) tetra(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) ethylenediaminetetraacetate;

(dd) tetra(1 -hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) ethylenediaminetetraacetate; (ee) penta(1-hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) diethylenetriamine- pentaacetate;

(ff) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) diethylenetriamine- pentaacetate;

(gg) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) diethylenetriaminepenta- acetate;

(hh) tri(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) nitrilotriacetate;

(ii) tri(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) nitrilotriacetate;

(jj) tri(1 -hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) nitrilotriacetate;

(kk) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-hydroxypiperidinium) diethylenetriamine- pentamethylenephosphonate;

(II) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-acetamidopiperidinium) diethylenetriamine- pentamethylenephosphonate;

(mm) penta(1 -hydroxy-2,2,6,6-tetramethyl-4-oxopiperidinium) diethylenetriamine- pentamethylenephosphonate or mixtures thereof.

The pretreatment can be applied to the wood by conventional techniques, for example by impregnating, spreading, brushing, dipping, deluging or spraying. Also impregnating under high pressure or under vacuum is possible.

Such a pretreatment of wood has been described in WO 2005/0051 14.

In a preferred embodiment the cork or wood substrate has been pretreated with an aqueous and/or organic solution of 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine.

The hindered amine compounds are known and partially commercially available, such as Lignostab® 1198 from Ciba Specialty Chemicals Inc. or may be produced by chemical standard methods. Examples are given in J. Polym Sci. Polym. Chem. Ed., 22, 277-281 (1984) and in US 4,831 134. The salts are readiliy prepared from the corresponding amine precursor and a suitable acid.

The intermediates needed to make the instant compounds are largely items of commerce.

For example the hindered amine compound is applied in an amount of 0.1-10 %, preferably from 0.1-5% and more preferably from 0.2-2% by weight based on the weight of the stain or impregantion.

A further aspect of the invention is the use of a combination of an organic UV-absorber selected from the group consisting of the hydroxybenzophenone, hydroxyphenylbenzo- triazole, oxanilide and hydroxyphenyltriazine UV-absorbers or mixtures thereof; and an inorganic UV-absorber selected from the group consisting of transparent iron oxide, transparent titanium dioxide, transparent zinc oxide, transparent cerium oxide and carbon black or mixtures thereof; in a weight ratio of organic UV-absorber to inorganic UV-absorber from 1000:1 to 10:1 for protecting cork or wood substrates from discoloration wherein the wood substrate is selected from the group consisting of beech, alder, meranti, oak, cherry, teak, nut redwood, mahogany, eucalyptus, american beech, durian, red cedar, leichhardt tree, champa, rubberwood, taiwan ash, campher tree, zebra wood, makha, rosewood, rain tree and ironwood.

Preferences and definitions have already been given. They apply also for the other aspect of the invention.

The following examples illustrate the invention.

Example 1 : Light stabilization of cork

The additives and pigments given in table 1 are added to the waterborne acrylic dispersion (see formulation table 2). The pigments are added pre-dispersed and used as concentrates (see table 3). The paint is applied on the cork panel by brush in two layers (approximately 100-1 10g/m 2 per brush) with a drying time of one day between each layer. The color difference (DE * ) is measured according to DIN 6174 before and after 100 hours exposure to Xenon lamp light according DIN EN ISO 11341 C as given below:

Machine type: Atlas Weather-O-meter Ci-65 A (two-tier rack) Light Source: 6.5 kW Xenon burner water-cooled Filter combination: Outer filter "Sodalime" (Window glass) / Inner filter Boro S Procedure: C Cycle Conditions:

Permanent light

0.35 VWm 2 @ 340 nm Irradiance, controlled (50±2) 0 C Black panel temperature (50±5) % ReI. humidity at the end of the dry period

Table 1 : UV-Absorber Combinations and Corresponding Color Differences after Exposure

1 ) Sicotrans® Yellow L1916 and Sicotrans® Red L 2815 are transparent iron oxides from BASF; FW 200 is a carbon black from Degussa

2) TINUVIN® 477 DW is a UV-Absorber (20% active UVA) from Ciba Specialty Chemicals Inc.

3) Based on total paint

4) Amount of inorganic and organic UVA corresponds to 2% active UVA

Table 2: Used Acrylic Dispersion

(1 ) Johnson Polymer B.V.

(2) Ciba Specialty Chemicals Inc.

(3) Dow Chemical Company

Table 3: Transparent iron oxide (TIO) concentrates 1

1 ) TIO concentrates are made according to Table 3 in 250ml glass jars, 100g Zirconia beads (0 1 mm), dispersed with Skandex Lau for 2h

2) EFKA 4550 and 2550 are from Ciba Specialty Chemicals

The above comparative experiments clearly show that the combination of a transparent iron oxide and an organic UV-absorber perform better than the single usage of a transparent iron oxide or the single usage of an organic UV-absorber, a synergistic effect is clearly achieved and almost no bleaching effect is visible.

Example 2: Waterborne Acrylic on Alder

The additives given in Table 1 are added to the waterborne acrylic dispersion (see formulation table 2). The pigments are added pre-dispersed and used as concentrate (see table 3). The paint is applied on the wood panel by brush in two layers (approximately 1 10g/m 2 per brush) with a drying time of one day between each layer. The color difference (DE * ) is measured according DIN 6174 before and after 100 hours exposure to Xenon lamp light according to DIN EN ISO 11341 C as given below:

Machine type: Atlas Weather-O-meter Ci-65 A (two-tier rack) Light Source: 6.5 kW Xenon burner water-cooled Filter combination: Outer filter "Sodalime" (Window glass) / Inner filter Boro S Procedure: C Cycle Conditions:

Permanent light

0.35 VWm 2 @ 340 nm Irradiance, controlled (50±2) 0 C Black panel temperature (50±5) % ReI. humidity at the end of the dry period

Table 1 : UV-Absorber Combinations and Corresponding Color Differences after Exposure

1 ) Sicotrans® Yellow L1916 and Sicotrans® Red L 2815 are transparent iron oxides from BASF

2) TINUVIN® 477 DW is a UV-Absorber (20% active UVA) from Ciba Specialty Chemicals Inc.

3) Based on total paint

4) Amount of inorganic and organic UVA corresponds to 2% active UVA

5 TINUVIN 5100 is a sterically hindered amine light stabilizer from Ciba Specialty Chemicals

Inc.

Table 2: Used Acr lic Dispersion

(1 ) Johnson Polymer B.V.

(2) Ciba Specialty Chemicals Inc.

(3) Dow Chemical Company

Table 3: Transparent iron oxide (TIO) concentrates 1

1 ) TIO concentrates are made according table 3 in 250ml glass jars, 100g Zirconia beads 1 mm), dispersed with Skandex Lau for 2h

2) EFKA 4550 and 2550 are from Ciba Specialty Chemicals Inc.

The above comparative experiments clearly show that the combination of a transparent iron oxide and an organic UV-absorber perform better than the single usage of a transparent iron oxide or the single usage of an organic UV-absorber, a synergistic effect is clearly achieved and almost no bleaching effect is visible.

Example 3: Solventborne Alkyd on Exotic Wood

The additives given in Table 1 are added to the solventborne alkyd paint (see formulation table 2). The pigment preparations are added in delivery form (see table 3). The paint is applied on the wood panel by brush in two layers (approximately 100 g/m 2 per brush) with a drying time of one day between each layer. The color difference (DE * ) is measured according DIN 6174 before and after 1000 hours exposure to Xenon lamp light according to DIN EN ISO 1 1341 C as given below:

Machine type: Atlas Weather-O-meter Ci-65 A (two-tier rack)

Light source: 6.5kW Xenon burner water-cooled

Filter combination: Outer filter Boro S / Inner filter Boro S

Procedure: A Cycle conditions: 102 min Light

0.35 VWm 2 @ 340 nm Irradiance, controlled (60±2) 0 C Black panel temperature (50±5) % ReI. humidity at the end of the dry period

18 min Light and Spray

0.35 VWm 2 @ 340 nm Irradiance, controlled (35±2) 0 C Black panel temperature (95±5) % ReI. humidity

Table 1 : UV-Absorber Combinations and Corresponding Color Differences after Exposure

1 ) Mix A, B and C are compositions as shown in table 3, based on SICOFLASH® pigment preparations from BASF

2) TINUVIN® 5060 is a blend of the UV-Absorber TINUVIN® 99-2 and the HALS TINUVIN® 123 (1 : 1 ) from Ciba Specialty Chemicals Inc.

3) Based on total paint

Table 2: Used Alkyd Dispersion

(1 ) Bayer Material Science (www.bayer.com)

(2) Ciba Specialty Chemicals Inc. (www.dba.com)

(3) Borchers GmbH (www.borchers.com)

Table 3: Transparent iron oxide (TIO) composition

1 ) Pigmented preparation from BASF (www.basf.de); highly concentrated paste based on organic binders and solvents; can be stirred directly into the binder. Used in delivery form

2) SICOFLASH® 1 P Schwarz 0054: 20% TIO

3) SICOFLUSH® 1 P GeIb 1916: 35% TIO

4) SICOFLUSH® 1 P Rot 2817: 35% TIO

The above comparative experiments clearly show that the combination of a transparent iron oxide and an organic UV-absorber perform better than the single usage of a transparent iron oxide or the single usage of an organic UV-absorber, a synergistic effect is clearly achieved and the color deviation is significantly reduced.