PEO-PPO-PEO TRIBLOCK COPOLYMERS AS ADDITIVES FOR EPOXIDE-ANHYDRIDE SYSTEMS

Abstract

The present invention relates to curable resin compositions, to methods for producing a cured composition using said curable resin compositions, and articles, in particular molded parts, produced by such methods.

Claims

1. A resin composition comprising at least one epoxy resin component and at least one curing component, wherein the resin composition further comprises at least one PEO-PPO-PEO triblock copolymer.

2. The resin composition according to claim 1, wherein the at least one PEO-PPO-PEO triblock copolymer in the resin composition is present in a range of 5-20 wt. %, based in each case on total weight of the resin composition.

3. The resin composition according to claim 1, wherein the at least one PEO-PPO-PEO triblock copolymer has a molecular weight of >6,000.

4. The resin composition according to claim 1, wherein the at least one PEO-PPO-PEO triblock copolymer has a molar mass fraction of PEO block polymers of 50%-90%.

5. The resin composition according to claim 1, wherein the at least one epoxy resin component is an epoxy compound selected from the group consisting of bis-(3,4-epoxycyclohexylmethyl) oxalate, bis-(3,4-epoxy-cyclohexylmethyl) adipate, bis-(3,4-epoxy-6-methylcyclohexylmethyl) adipate, bis-(3,4-epoxycyclohexylmethyl) pimelate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, bis-(3,4-epoxycyclohexyl) adipate, 3,4-epoxy-1-methylcyclohexylmethyl-3,4-epoxy-1-methylcyclohexane carboxylate, and mixtures thereof.

6. The resin composition according to claim 1, wherein the at least one curing component comprises at least one anhydride curing agent.

7. The resin composition according to claim 6, wherein the at least one anhydride curing agent is selected from hexahydrophthalic anhydride, methylhexahydrophthalic anhydride and mixtures thereof.

8. A method for producing a cured composition, comprising steps of (1) providing a resin composition according to claim 1; and (2) curing the resin composition to obtain a cured composition.

9. The method according to claim 8, wherein the method is a transfer molding (RTM) method and the resin composition is a reactive injection resin.

10. The method according to claim 9, wherein step (1) comprises injecting the resin composition into a die into which fibers or semi-finished fiber products are inserted, said semi-finished fiber products being selected from prewovens and/or preforms.

11. The method according to claim 8, wherein (a) the resin composition in step (2) is cured at a temperature of between 80° C. and 240° C. for 0.01 to 10 hours; or (b) the resin composition in step (2) is first cured at a temperature of between 70° C. and 150° C. for 0.1 hours to 3 hours; and then is cured at least twice at a temperature of between 110° C. and 260° C., for 0.1 hours to 3 hours in each case.

12. A cured composition made according to the method of claim 8.

13. The cured composition according to claim 12, wherein the K1c value of the cured composition is at least 0.8.

14. The cured composition according to claim 12, wherein the cured composition has a glass transition temperature T.sub.g≥180° C.

15. The cured composition according to claim 12, wherein the cured composition is a molded part, optionally a fiber-reinforced molded part.

Description

EXAMPLES

[0079] The material properties of resin compositions consisting of an epoxide component (110 g of a cycloaliphatic epoxide (epoxide weight 130 g/mol; viscosity 240 mPas at room temperature) plus 0.15 g of a multifunctional fatty acid ester) and a curing component (140 g methyl hexahydrophthalic anhydride plus 4.4 g tributyl(ethyl)phosphonium diethyl phosphate) with regard to the composition and amount of PEO-PPO-PEO-based block copolymers are listed below in table form. For the production of corresponding pure resin panels, the listed raw materials of the epoxy resin component were first weighed into a speed mixer and mixed for 5 minutes at 800 rpm in a vacuum. The raw materials of the curing component were then weighed and mixed again for 5 minutes at 800 rpm in a vacuum. The mixtures obtained in this way were then poured into correspondingly prepared stainless steel molds preheated to 120° C. in the autoclave, and first cured in the autoclave at 120° C. for 30 minutes and then at 180° C. for one hour.

TABLE-US-00001 T.sub.g Additive (DSC) Visual No. Additive [wt. %] [° C.] K1c appearance 1 Fortegra 100.sup.a) 10.54 206 0.80 clear, colorless 2 Pluronic PE 10500.sup.b) 10.54 203 0.84 clear, yellow- brown 3 Pluronic PE 10500 15.02 186 0.85 clear, yellow- brown 4 Pluronic L64.sup.c) 10.58 195 0.52 clear, colorless 5 Pluronic L121.sup.d) 10.58 207.5 0.75 slightly cloudy 6 Pluronic F108.sup.e) 10.58 222 1.05 clear, slightly yellowish 7 Pluronic F127.sup.f) 10.58 205.6 0.97 clear, slightly yellowish .sup.a)PPO-PBO diblock copolymer; .sup.b)PEO-PPO-PEO triblock copolymer, MW PPO = 3,250, MW PEO = 3,250, total MW = 6,500; .sup.c)PEO-PPO-PEO triblock copolymer, MW PPO = 1,750, MW PEO = 1,167, total MW = 2,917; .sup.d)PEO-PPO-PEO triblock copolymer, MW PPO = 4,000, MW PEO = 444, total MW = 4,444; .sup.e)PEO-PPO-PEO triblock copolymer, MW PPO = 3,250, MW PEO = 13,000, total MW = 16,250; .sup.f)PEO-PPO-PEO triblock copolymer, MW PPO = 4,000, MW PEO = 9,333, total MW = 13,333.