Prepregs and cured in place solid surfaces prepared therefrom
View Patent ↗A prepreg which is capable of being cured-in-place into a solid surface by irradiation, heating or a combination of the two is prepared. The cured-in-place solid surfaces can be used as veneer cladding for rigid substrates such as floor and wall tiles, kitchen and bath counter tops, sinks, cabinet door veneers, bath surrounds, architectural surfaces such as columns and roofs and the like.
1. A prepreg comprising the reaction product of a curable composition which comprises: a) polymerizable component that comprises i) a reactive material which reactive material is selected from the group consisting of acrylate monomers, acrylate oligomers, acrylate polymers and combinations thereof, ii) a Michael Addition reactive thickening agent having a β-dicarbonyl reactive methylene Michael Donor, and iii) an activated olefin-functional Michael Acceptor; b) an additive component that comprises a catalyst for the Michael Addition reactive thickening agent and a photoinitiator or peroxide or both; and c) a filler wherein the prepreg comprises a gel having a thermosettable resin that is crosslinked with a crosslink density which imparts recoverable elasticity to the prepreg and wherein the prepreg is a castable paste and the polymerizable component comprises about 3 to about 20 weight percent of the thermosettable resin or a prepolymer and the reactive material in amounts of about 5 to about 30 weight percent and the Michael Addition reactive thickening agent comprises the β-dicarbonyl reactive methylene Michael Donor in amounts of about 3 to about 25 weight percent and the activated olefin-functional Michael Acceptor in amounts of about 4 to about 25 weight percent.
2. The prepreg of claim 1 wherein the amount of the polymerizable component is about 15 to about 55 weight percent; the amount of the filler component is about 45 to about 85 weight percent, and the amount of the additive component is about 0.2 to 3 weight percent.
3. The prepreg of claim 1 wherein the amount of the polymerizable component is about 25 to about 45 weight percent; the amount of the filler component is about 50 to about 75 weight percent, and the amount of the additive component is about 0.3 to 2 weight percent.
4. The prepreg of claim 1 which further comprises an unreactive thermoplastic resin.
5. The prepreg of claim 1 wherein the additive component comprises a member selected from the group consisting of a photoinitiator in amounts of about 0.001 to about 0.2 weight percent; a peroxide in amounts of about 0.05 to about 1 weight percent; and mixtures thereof in amounts of about 0.06 to about 1.2 weight percent.
6. The prepreg of claim 1 which comprises the Michael Addition reactive thickening agent catalyst in amounts of about 0.025 to about 0.25 weight percent.
7. The prepreg of claim 1 further comprising an air-release agent component in amounts of about 0.5 to about 1.5 weight percent.
8. The prepreg of claim 1 which further comprises a stabilizer component.
9. The prepreg of claim 1 which further comprises a flexibilizing component and in amounts of about 2 to about 25 weight percent.
10. The prepreg of claim 1 which has a shelf life in an uncured state of greater than 100 hours at 60° C. or greater than 30 days at room temperature.
11. The prepreg according to claim 1 comprising a Michael addition product.
12. The prepreg according claim 11 wherein the Michael product comprises at least one member selected from the group consisting of polyester diols or polyols which are capped with acetoacetate functionalities; polyesters containing mid-chain β-dicarbonyl-functional esters and hydrogenated bisphenol A diacetoacetate.
13. The prepreg according to claim 1 which comprises a photoinitiator.
14. The prepreg according to claim 13 wherein the photoinitiator comprises a visible light activated photoinitiator.
15. The prepreg according to claim 13 wherein the photoinitiator comprises at least one member selected from the group consisting of an acylphosphine oxide and a cyanine borate.
16. The prepreg according to claim 15 wherein the acylphosphine oxide is bis (2,4,6-trimethylbenzoyl)phenylphosphine oxide.
17. The prepreg according to claim 15 wherein the cyanine borate is an organic-soluble salt of a cationic cyanine dye and tetraalkyl, and/or aryl functional borate anion.
18. The prepreg according to claim 1 which comprises a peroxide.
19. The prepreg according to claim 1 wherein said filler is at least one member selected from the group consisting of alumina, alumina monohydrate, aluminum trihydrate, aluminum hydroxide, aluminum oxide, aluminum sulfate, aluminum phosphate, aluminum silicate, borosilicate, calcium sulfate, calcium phosphate, calcium carbonate, calcium hydroxide, magnesium sulfate, magnesium phosphate, magnesium carbonate, magnesium hydroxide, and silica.
20. The prepreg according to claim 19 wherein said filler comprises aluminum trihydrate.
21. The prepreg according to claim 1 wherein said filler comprises a Group II metal in combination with an oxide of aluminum and/or silica.
22. The prepreg according to claim 1 which further comprises a cure rate-enhancer.
23. The prepreg according to claim 22 wherein said cure rate-enhancer is at least one member selected from the group consisting of mercaptan,disulfide, polysulfide, phosphine, phosphine oxide, vinyl triazine, branched alkyl aryl amine, sulfinamine, sulfonamide, alkyl thiourea, and aryl thiourea.
24. The prepreg according to claim 11 wherein the Michael Addition product comprises poly(meth)acrylates having side-chain acetoacetate groups.
25. The prepreg according to claim 11 wherein the Michael Addition product comprises a reaction product of a crystalline diacetoacetate and a crystalline poly acrylate.
26. The prepreg according to claim 11 wherein the Michael Addition product comprises chain extended products formed by a prereaction between a crystalline diacetoacetate and a crystalline poly acrylate later reacted into a cross linked Michael Addition polymer network.
27. A method of making the prepreg according to claim 1 which comprises obtaining the polymerizable component a) and then adding and mixing with the polymerizable component a), a reactive thickening agent, photoinitiator or peroxide or both and a filler and removing entrained air bubbles.
28. The method according to claim 27 wherein release of entrained air is facilitated by using a vacuum and/or vibration.
29. The method of making the prepreg according to claim 27 which further comprises partially curing to thereby obtain the prepreg.
30. The method according to claim 27 wherein the partially cured prepreg test sample has a degree of sag from horizontal of less than 20 degrees.
31. The method according to claim 27 wherein the partially cured prepreg test sample has a degree of sag from horizontal of less than 5 degrees.
32. The method according to claim 27 wherein said prepreg is formed between two film layers.
33. A method of preparing a solid surface article which comprises curing the prepreg of claim 1 .
34. The method according claim 33 wherein said curing comprises radiation.
35. The method according claim 34 wherein said radiation comprises ambient light.
36. The method according claim 33 wherein the curing comprises heating.
37. The method according claim 33 wherein the curing comprises a combination of radiation and heat.
38. The method according to claim 32 wherein the cured prepreg has a linear shrinkage on cure of less than 1 mil/in.
39. A solid surface article comprising the cured prepreg of claim 1 bonded onto a supporting substrate.