Curable compositions
View Patent ↗The present invention relates to curable compositions of benzoxazines, a combination of adducts one of which is prepared from hydroxy-containing compounds, isocyanate-containing compounds and phenolic compounds and the second of which is prepared from the first adduct and epoxy-containing compounds and phenolic compounds, epoxy resins and optionally tougheners.
1. A curable composition comprising:
A) a benzoxazine component,
B) a combination of two adducts a first adduct of which is prepared from hydroxy-containing compounds, isocyanate-containing compounds, and an amino phenolic compound, wherein the first adduct has a molecular weight in the range of 55,000 to 90,000 Mn, and a second adduct of which is prepared from the first adduct, an epoxy-containing compound and a phenolic compound,
C) an epoxy resin component, and
D) one or more tougheners in addition to the combination of adducts of B).
2. A composition according to claim 1 , wherein the benzoxazine component comprises one or more of
wherein o is 1-4, X is selected from the group consisting of a direct bond (when o is 2), alkyl (when o is 1), alkylene (when o is 2-4), carbonyl (when o is 2), thiol (when o is 1), thioether (when o is 2), sulfoxide (when o is 2), and sulfone (when o is 2), R 1 is selected from the group consisting of hydrogen, alkyl, and aryl, and R 4 is selected from the group consisting of hydrogen, halogen, alkyl, and alkenyl, or
wherein p is 2, Y is selected from the group consisting of biphenyl (when p is 2), diphenyl methane (when p is 2), diphenyl isopropane (when p is 2), diphenyl sulfide (when p is 2), diphenyl sulfoxide (when p is 2), diphenyl sulfone (when p is 2), and diphenyl ketone (when p is 2), and R 4 is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, and aryl.
3. A composition according to claim 2 , wherein the benzoxazine component comprises one or more of
wherein X is selected from the group consisting of a direct bond, CH 2 , C(CH 3 ) 2 , C═O, S, S═O and O═S═O, and R 1 , R 2 , and R 3 are the same or different and is selected from the group consisting of hydrogen, alkyl, and aryl, and R 4 is selected from the group consisting of a hydrogen, halogen, alkyl, alkenyl and aryl.
4. A composition according to claim 1 , wherein the benzoxazine component comprises one or more of
5. A composition according to claim 1 , wherein the benzoxazine component is present in an amount in the range of about 10 to about 99 percent by weight, based on the total weight of the composition.
6. A composition according to claim 1 , wherein the epoxy resin component is a member selected from the group consisting of C 1 -C 28 alkyl-, polyphenol glycidyl ethers; polyglycidyl ethers of pyrocatechol, resorcinol, hydroquinone, 4,4′-dihydroxydiphenyl methane, 4,4′-dihydroxy-3,3′-dimethyldiphenyl methane, 4,4′-dihydroxydiphenyl dimethyl methane, 4,4′-dihydroxydiphenyl methyl methane, 4,4′-dihydroxydiphenyl cyclohexane, 4,4′-dihydroxy-3,3′-dimethyldiphenyl propane, 4,4′-dihydroxydiphenyl sulfone, and tris(4-hydroxyphenyl)methane; polyglycidyl ethers of transition metal complexes; chlorination and bromination products of pyrocatechol, resorcinol, hydroquinone, 4,4′-dihydroxydiphenyl methane, 4,4′-dihydroxy-3,3′-dimethyldiphenyl methane, 4,4′-dihydroxydiphenyl dimethyl methane, 4,4′-dihydroxydiphenyl methyl methane, 4,4′-dihydroxydiphenyl cyclohexane, 4,4′-dihydroxy-3,3′-dimethyldiphenyl propane, 4,4′-dihydroxydiphenyl sulfone, and tris(4-hydroxyphenyl)methane; polyglycidyl ethers of novolacs; polyglycidyl ethers of diphenols obtained by esterifying ethers of diphenols obtained by esterifying salts of an aromatic hydrocarboxylic acid with a dihaloalkane or dihalogen dialkyl ether; polyglycidyl ethers of polyphenols obtained by condensing phenols and long-chain halogen paraffins containing at least two halogen atoms; phenol novolac epoxy; cresol novolac epoxy; and combinations thereof.
7. A composition according to claim 1 , wherein the toughener is a member selected from the group consisting of 1,3-butadiene/acrylonitrile, 1,3-butadiene/(meth) acrylic acid esters, 1,3-butadiene/methacrylic acid esters, a 1,3-butadiene/acrylonitrile/styrene graft copolymer, a 1,3-butadiene/methyl methacrylate/styrene graft copolymer, a 1,3-butadiene/acrylonitrile copolymer, core shell polymers, polyether sulfones, polyamide imides, polysulfones, polyether ketones and combinations thereof.
8. A composition according to claim 1 , further comprising an inorganic filler component.
9. A composition according to claim 8 , wherein the inorganic filler component is a silica having a particle size in the nanoscale range.
10. A prepreg comprising a layer of fibers infused with the composition of claim 1 .
11. Cured reaction products of the prepreg according to claim 10 .
12. A process for producing a prepreg, steps of which comprise:
A) providing a layer of fibers;
B) providing the composition according to claim 1 ; and
C) joining the composition and the layer of fibers to form a prepreg assembly, and exposing the resulting prepreg assembly to elevated temperature and pressure conditions sufficient to infuse the layer of fibers with the heat curable composition to form a prepreg.
13. A prepreg made by the process according to claim 12 .
14. A process for producing a prepreg, steps of which comprise:
A) providing a layer of fibers;
B) providing the composition according to claim 1 in liquid form;
C) passing the layer of fibers through the liquid heat curable composition to infuse the layer of fibers with the heat curable composition; and
D) removing excess heat curable composition from the prepreg assembly.
15. A prepreg made by the process according to claim 14 .
16. A towpreg comprising:
A) a bundle of fibers infused with the composition according to claim 1 .
17. Cured reaction products of the towpreg according to claim 16 .
18. A process for producing a towpreg, steps of which comprise:
A) providing a bundle of fibers;
B) providing the composition according to claim 1 ; and
C) joining the heat curable composition and the bundle of fibers to form a towpreg assembly, and exposing the resulting towpreg assembly to elevated temperature and pressure conditions sufficient to impregnate the bundle of fibers with the heat curable composition to form a towpreg.
19. A towpreg made by the process according to claim 18 .
20. A process for producing a towpreg, steps of which comprise:
A) providing a bundle of fibers;
B) providing the composition according to claim 1 in liquid form;
C) passing the bundle of fibers through the liquid heat curable composition to impregnate the bundle of fibers with the heat curable composition; and
D) removing excess heat curable composition from the towpreg assembly, thereby forming a towpreg.
21. A towpreg made by the process according to claim 20 .
22. An adhesive composition comprising the composition according to claim 1 .
23. An adhesive composition according to claim 22 , further comprising one or more of an adhesion promoter, a flame retardant, a thermoplastic additive, a reactive or unreactive diluent, and a thixotrope.
24. Cured reaction product of the adhesive composition according to claim 23 .
25. An adhesive film comprising the composition according to claim 22 .
26. An adhesive film according to claim 25 , further comprising a support selected from the group consisting of nylon, glass, carbon, polyester, polyalkylene, quartz, polybenzimidazole, polyetheretherketone, polyphenylene sulfide, poly p-phenylene benzobisoxazole, silicon carbide, phenolformaldehyde, phthalate and napthenoate.
27. Cured reaction product of the adhesive film according to claim 26 .
28. A composition according to claim 1 , wherein the first adduct has a molecular weight of 65,000 to 75,000 Mn.
29. A composition according to claim 1 , wherein the first adduct has a molecular weight of at least 62,000 Mn.
30. A composition according to claim 1 , wherein the first adduct has a softening point below 120° C.
31. A composition according to claim 1 , wherein the toughener is a polyether sulfone, which contains the structure represented below