Composition capable of radiation activated catalysis and radiation curable urethane containing the composition

1. A radiation curable urethane composition comprising

a) a composition capable of radiation activated catalysis comprising a metal compound having catalytic activity, a mercapto compound which passivates the metal compound by inhibiting the catalytic activity of the metal compound; and an olefinic compound which reacts with the mercapto compound wherein the reaction between the mercapto compound and the olefinic compound is caused by the radiation;

b) a hydroxyl compound; and

c) an isocyanate compound.

2. The composition as claimed in claim 1 , wherein the metal compound is selected from the group consisting of a tin compound, a bismuth compound, a germanium compound, a cobalt compound, a manganese compound and mixtures thereof.

3. The composition as claimed in claim 1 , wherein the mercapto compound is selected from the group consisting of trimethylol propane tri-(3-mercapto propionate), pentaerythritol tetra-(3-mercapto propionate), glycol di-(3-mercapto propionate), glycol dimercapto acetate, trimethylol propane trithioglycolate, mercapto diethyl ether, ethane dithiol, thiolactic acid, mercapto propionic acid, mercapto propionic acid esters, thiophenol, thio acetic acid, 2-mercapto ethanol, 1, 4-butanedithiol, 2,3-dimercapto propanol, toluene-3,4-dithiol, alpha,alpha'-dimercapto-para-xylene, thiosalicylic acid, mercapto acetic acid, dodecane dithiol, didodecane dithiol, di-thio phenol, di-para-chlorothiophenol, dimercapto benzothiazole, 3,4-dimercapto toluene, allyl mercaptan, benzyl mercaptan, 1,6-hexane dithiol, 1-octane thiol, para-thiocresol, 2,3,5,6-tetrafluorothiophenol, cyclohexyl mercaptan, methylthioglycolate, mercapto pyridines, dithioerythritol, 6-ethoxy-2-mercaptobenzothiazole, d-limonene dimercaptan, γ-mercapto silane and mixtures thereof.

4. The composition as claimed in claim 1 , wherein the olefinic compound is selected from the group consisting of diallyl phthalate, acrylic acid, methacrylic acid, alkyl acrylate, alkyl methacrylate, acrylamide and mixtures thereof.

5. The composition as claimed in claim 1 , wherein the metal compound is selected from the group consisting of dibutyltindilaurate, stannous acetate, stannic oxide, stannous octoate, dibutyltin dioctoate, tin mercaptides, stannous citrate, stannous oxylate, stannous chloride, stannic chloride, tetra-phenyl tin, tetra-butyl tin, tri-n-butyl tin, tri-n-butyl tin acetate, dialkyl tin dicarboxylates, dimethyl tin dichloride, bismuth tricarboxylates, bismuth nitrate, bismuth halides, bismuth sulfide, basic bismuth dicarboxylates, and mixtures thereof.

6. The radiation curable urethane composition as claimed in claim 1 , wherein the hydroxyl compound is a polyol.

7. The radiation curable urethane composition as claimed in claim 6 , wherein the polyol is an aliphatic polyol.

8. The radiation curable urethane composition as claimed in claim 1 , wherein the hydroxyl compound is selected from the group consisting of hydroxypolyester, hydroxypolyethers, hydroxypolythioester, hydroxypolyacetal, hydroxypolycarbonate, dimeric fatty alcohol, esteramide, polyetherpolyol, polyesterpolyol, polycarbonatepolyol, ethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bis -(hydroxymethy)-cyclohexane, bis-(hydroxymethyl)-(tricycle-[5.2.1.0 2.6 ]-decane, 1,4-bis-(2-hydroxyethoxy)-benzene, 2-methyl-1,3-propanediol, 2,2,4-trimethylpentanediol, 2-ethyl-1,3-hexanediol, dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A, tetra-bromobisphenol A, glycerol, trimethylolpropane, 1,2,6-hexanetriol, 1,2,4-butanetriol, pentaerythritol, quinitol, mannitol, sorbitol, methylglycoside 1,4:3,6-dianhydrohexitol and mixtures thereof.

9. The radiation curable urethane composition as claimed in claim 1 , wherein the isocyanate compound is a polyisocyanate.

10. The radiation curable urethane composition as claimed in claim 9 , wherein the polyisocyanate is an aliphatic polyisocyanate.

11. The radiation curable urethane composition as claimed in claim 1 , wherein the isocyanate compound is selected from the group consisting of hexamethylene diisocyanate, 4,4′-toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethyl polphenyl isocyanate (Polymeric MDI or PAPI), m-phenylene diisocyanates, p-phenylene diisocyanates, bitolylene diisocyanate, triphenylmethane triisocyanate, tris-(4-isocyanatophenyl)thiophosphate, cyclohexane diisocyanate (CHDI), bis-(isocyanatomethyl)cyclohexane (H 6 XDI), dicyclohexylmethane diisocyanate (H 12 MDI), trimethyihexane diisocyanate, dimer acid diisocyanate (DDI), dicyclohexylmethane diisocyanate, dimethyl derivatives of dicyclohexylmethane diisocyanate, trimethyl hexamethylene diisocyanate, lysine diisocyanate, methyl ester of lysine diisocyanate, isophorone diisocyanate, methyl cyclohexane diisocyanate, 1,5-naphthalene diisocyanate, triphenyl methane triisocyanate, xylene diisocyanate, methyl derivatives of xylene diisocyanate, hydrogenated derivatives of xylene diisocyanate, polymethylene polyphenyl isocyanates, chlorophenylene-2,4-diisocyanate and mixtures thereof.

12. A coating composition comprising the radiation curable urethane composition as claimed in claim 1 .

13. The composition as claimed in claim 1 , wherein the radiation is actinic radiation or e-beam radiation.

14. The composition as claimed in claim 1 , wherein the radiation is UV radiation.