Epoxy resin systems
Compositions and methods for forming epoxy resin systems are provided. In one embodiment, a composition is provided for an epoxy resin system including an epoxy resin blend comprising an epoxy resin, a first curing agent selected from the group of a polyarylene alkylphosphonate, a polyarylene arylphosphonate, and combinations thereof, and a second curing agent.
1. An epoxy resin system, consisting essentially of:
an epoxy resin blend consisting essentially of:
a liquid epoxy resin based on aromatic compounds selected from the group consisting of bisphenol F, bisphenol A, 1,1-bis(4-hydroxyphenyl)ethane, 1,1-dichloro-2,2-bis(4-hydroxyphenyl)ethene, phenolic novolacs, phenolic resoles, and combinations thereof;
a first curing agent consisting essentially of:
a polyarylene alkylphosphonate; and
a polyarylene arylphosphonate;
an optional monofunctional epoxy additive; and
an optional additive selected from the group consisting of an additive phosphorus compound, a diluent, and combinations thereof; and
a second curing agent selected from the group consisting of a compound having an imidazole group, a compound having a fused imidazole ring, and combinations thereof.
2. The epoxy resin system of claim 1 , wherein the polyarylene alkylphosphonate or polyarylene arylphosphonate is selected from the group of poly-(m-phenylene methylphosphonate), poly-(m-phenylene phenylphosphonate), and combinations thereof.
3. The epoxy resin system of claim 1 , wherein, if present, the additive phosphorus compound is selected from the group consisting of a non-polyarylene phosphonate, a phosphazene, an alkyl phosphate, an aryl phosphate, an alkyl phosphite, an aryl phosphite, and combinations thereof.
4. The epoxy resin system of claim 3 , wherein the additive phosphorus compound is selected from the group of dimethyl methylphosphonate, diethyl ethylphosphonate, P,P′,P″,P,P′,P″-hexamethoxyphosphazene, P,P′,P″,P,P′,P″-hexaphenoxyphosphazene, dimethyl phosphite, diethyl N,N-bis (2-hydroxyethyl) aminomethylphosphonate, tributyl phosphate, triphenyl phosphate, diphenyl methylphosphonate, diphenyl phenylphosphonate, resorcinol bis(diphenyl phosphate), t-butylated triphenyl phosphate, bisphenol A bis(diphenyl phosphate), bisphenol F bis(diphenyl phosphate), and combinations thereof.
5. The epoxy resin system of claim 1 , wherein the total phosphorus content is greater than 4 wt. % of the epoxy resin system/epoxy resin blend.
6. The epoxy resin system of claim 1 , wherein, if present, the diluent is selected from the group consisting of monoglycidyl ethers of alcohols, polyglycidyl ethers of non-aromatic glycols or triols or polyols, polyglycols, glycidyl esters, and combinations thereof.
7. The epoxy resin system of claim 1 , wherein the compound having an imidazole group is selected from the group consisting of imidazole, 1-methylimidazole, 2-methylimidazole, 2-propylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and combinations thereof.
8. The epoxy resin system of claim 1 , wherein the compound having a fused imidazole ring is selected from the group consisting of benzimidazole, toluimidazole, and combinations thereof.
9. The epoxy resin system of claim 1 , wherein the epoxy resin blend consists essentially of:
from about 40 wt. % to about 85 wt. % of the epoxy resin;
from about 15 wt. % to about 60 wt. % of the first curing agent comprising polyarylene alkylphosphonate and a polyarylene arylphosphonate;
from about 0 wt. % to about 30 wt. % of an additive phosphorus compound; and
from about 0 wt. % to about 20 wt. % of a diluent, wherein the total of all components are 100 wt. % of the epoxy resin blend.
10. The epoxy resin system of claim 1 , wherein the epoxy resin system consists essentially of:
from about 60 wt. % to about 99.8 wt. % of the epoxy resin blend; and
from about 0.2 wt. % to about 40 wt. % of the second curing agent.
11. The epoxy resin system of claim 1 , wherein the epoxy resin system is free of fillers.