Hydrogenation of methylenedianiline homologs and epoxy resins cured with same
View Patent ↗This invention relates to improved polyepoxide resins cured with a mixture of methylene bridged poly(cycloaliphatic-aromatic)amines and a process for preparing such polyepoxide resins as well as to the methylene bridged poly(cycloaliphatic-aromatic)amine compositions and a method of making them. The improvement resides in using a curative (herein referred to as “Heavy MPCA”) comprised of the partially hydrogenated condensation product of formaldehyde and aniline or methyl substituted aniline containing a substantial amount (from 35 to 85% by weight, preferably 40 to 60% by weight) of oligomers in the form of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15 aniline or methyl substituted aniline derivatives.
1. In a polyepoxide resin comprising the reaction product of a polyglycidyl ether of a polyhydric alcohol having terminal 1,2 epoxy groups cured with a polyamine curative, the improvement which comprises said curative comprising a methylene bridged poly(cyclohexyl-aromatic)amine mixture herein designated Heavy MPCA, wherein the Heavy MPCA contains 3 ring and higher ring components, represented by the formulas:
wherein R is hydrogen or methyl x is 1-13, y is 1-13, z is 1-13, the sum of x, y and z is from 3 to 15, p is 0-14, q is 0-14, the sum of p and q is from 1-14, r is 0-14, s is 0-14, the sum of r and s is from 1-14, u is 0-14, v is 0-14, the sum of u and v is 1-14, and the total number of rings is between 3 and 15 and at least 15-40% of said Heavy MPCA is non-elutable as determined by gas chromatography at a 300° C. injector temperature and said Heavy MPCA comprising at least a portion of said polyamine curative.
2. The polyepoxide resin of claim 1 wherein said Heavy MPCA has an amine hydrogen equivalent of 50 to 60.
3. The polyepoxide resin claim 2 wherein the polyglycidyl ether of a polyhydric alcohol is a polyglycidyl ether of bisphenol A or a polyglycidyl ether of bisphenol F.
4. The polyepoxide resin claim 3 wherein R in the formulas is hydrogen.
5. The polyepoxide resin claim 4 wherein the polyglycidyl ether of a polyhydric alcohol is a polyglycidyl ether of bisphenol A.
6. The polyepoxide resin claim 5 wherein at least 20-40% by weight of the Heavy MPCA is non-elutable.
7. In a polyepoxide resin comprising the reaction product of a polyglycidyl ether of a polyhydric alcohol having terminal 1,2 epoxy groups cured with a polyamine curative, the improvement which comprises: said polyepoxide resin at least partially cured with a polyamine curative mixture of partially hydrogenated methylene bridged aniline derivatives, said polyamine curative mixture is formed by hydrogenating a feedstock having as a component thereof a methylene bridged aniline composition having from 35 to 85% oligomer content by weight followed by distillation of the resulting reaction product for removing 2-ring methylene bridged aniline therefrom and recovering a bottoms fraction herein referred to as Heavy MPCA as said polyamine curative mixture.
8. The polyepoxide resin claim 7 wherein the polyglycidyl ether of a polyhydric alcohol is a polyglycidyl ether of bisphenol A or a polyglycidyl ether of bisphenol F.
9. The polyepaxide resin claim 8 wherein the polyglycidyl ether of a polyhydric alcohol is a polyglycidyl ether of bisphenol A.
10. The polyepoxide resin claim 9 wherein at least 20-40% by weight of the Heavy MPCA is a non-elutable fraction as determined by gas chromatography at a 300° C. injector temperature and the secondary amine concentration is less than 20% by weight.
11. The polyepoxide resin of claim 10 wherein the ratio of 5 or more ring components to 2-4 ring components in the non-elutable fraction as determined by MALDI analysis is greater than 1:1.
12. The polyepoxide of claim 10 wherein the ratio of 5 or more ring components to 2-4 ring components in the non-elutable fraction as determined by MALDI analysis is greater than 2:1.
13. The polyepoxide resin of claim 9 wherein the feedstock for the methylene bridged aniline composition has from 40 to 60% oligomer content by weight.
14. In a process for forming an epoxy resin by reacting a polyglycidyl ether of a polyhydric phenol with a polyamine curative wherein the ratio of polyglycidyl ether of a polyhydric phenol to polyamine curative is from 0.6-1.7 amine hydrogens per epoxide equivalent of polyglycidyl ether of a polyhydric phenol, the improvement which comprises utilizing a polyamine curative mixture designated Heavy MPCA, wherein the Heavy MPCA contains 3 ring and higher ring components, represented by the formulas:
wherein R is hydrogen or methyl, x is 1-13, y is 1-13, z is 1-13, the sum of x, y and z is from 3 to 15, p is 0-4, q is 0-4, the sum of p and q is from 1-14, r is 0-4, s is 0-4, the sum of r and s is from 1-14, u is 0-4, v is 0-4, the sum of u and v is 1-14, and at least a portion of said polyamine curative has a total number of rings between 3 and 15.
15. The process of claim 14 wherein at least 20-40% by weight of the Heavy MPCA employed as said polyamine curative is a non-elutable fraction as determined by gas chromatography at a 300° C. injector temperature and the secondary amine concentration is less than 20% by weight.
16. The process of claim 15 wherein the polyglycidyl ether of a polyhydric phenol is a polyglycidyl ether of bisphenol A or a polyglycidyl ether of bisphenol F.
17. The process of claim 16 wherein R in the formulas is hydrogen.
18. The process of claim 17 wherein the polyglycidyl ether is a polyglycidyl ether of bisphenol A.
19. The process of claim 18 wherein the ratio of 5 or more ring components to 2-4 ring components in the non-elutable fraction as determined by MALDI analysis is greater than 2:1.
20. A methylene bridged poly(cyclohexyl-aromatic)amine mixture containing 3 ring and higher ring components, represented by the formulas:
wherein R is hydrogen or methyl, x is 1-13, y is 1-13, z is 1-13, the sum of x, y and z is from 3 to 15, p is 0-14, q is 0-14, the sum of p and q is from 1-14, r is 0-14, s is 0-14, the sum of r and s is from 1-14, u is 0-14, v is 0-14, the sum of u and v is 1-14, and the total number of rings is between 3 and 15 and at least 15-40 % of said mixture is non-elutable as determined by gas chromatography at a 3000° C. injector temperature.
21. In a process for forming a partially hydrogenated methylene bridged aniline mixture by the partial hydrogenation of methylenedianiline having oligomers therein, the improvement which comprises forming a partially hydrogenated methylene bridged aniline mixture containing 3 ring and higher ring components, represented by the formulas:
wherein R is hydrogen or methyl, x is 1-13, y is 1-13, z is 1-13, the sum of x, y and z is from 3 to 15, p is 0-4, q is 0-4, the sum of p and q is from 1-14, r is 0-4, s is 0-4, the sum of r and s is from 1-14, u is 0-4, v 0-4, the sum of u and v is 1-14, and the total number of rings is between 3 and 15, and at least 15-40% by weight is a non-elutable fraction as determined by gas chromatography at a 300° C. injector temperature.