摘要:
A polysiloxane-modified epoxy-based encapsulation composition comprising an epoxy resin, a curing agent for the epoxy resin, a polylactone-polysiloxane block copolymer, and a filler is described. The powder moulding compositions provide a low internal stress epoxy composition without significantly sacrificing T g .
摘要:
Glycidyl ethers of hydroxyalkyl carbamates of the general formula I
in which R is a C 1-15 aliphatic or cycloaliphatic linking group; R' is H or C 1-3 alkyl, at least one R' being hydrogen; m is 0, 1, 2 or 3; n is 1, 2, 3 or 4; and m + n is 2, 3 or 4, are prepared which are suitable for resinous binders for coatings and as crosslinking agents for carboxyl-functional resins such as acrylic resins.
摘要:
A polysiloxane-modified epoxy-based encapsulation composition comprising an epoxy resin, a curing agent for the epoxy resin, a polylactone-polysiloxane block copolymer, and a filler is described. The powder moulding compositions provide a low internal stress epoxy composition without significantly sacrificing T g .
摘要:
A composition comprising (a) a diglycidyl ether of the formula in which each R is selected from alkaryl, cycloalkyl, aromatic, heterocyclic, -SO₂-, -O-, and -S-, and each Rʹ is independently selected from H, lower alkyl and halide; (b) a normally liquid elastomeric polydiene comprising carboxyl and/or amine groups and having a molecular weight of from 2000 to 10000, (c) a polyaromatic polyamine curing agent for the diglycidyl ether, present in a stoichiometric excess, with respect to the diglycidyl ether, of at least 10 per cent.
(a) a diglycidyl ether of the formula in which each R is selected from alkaryl, cycloalkyl, aromatic, heterocyclic, -SO₂-, -O-, and -S-, and each Rʹ is independently selected from H, lower alkyl and halide; (b) a normally liquid elastomeric polydiene comprising carboxyl and/or amine groups and having a molecular weight of from 2000 to 10000, (c) a polyaromatic polyamine curing agent for the diglycidyl ether, present in a stoichiometric excess, with respect to the diglycidyl ether, of at least 10 per cent.
摘要:
A process is described for preparing thermoset composite articles under relatively mild conditions. The process includes exposing a laminate comprising a partially-cured thermosettable resin and a fibrous substrate to an elevated temperature which increases over time, the elevated temperature being below the glass transition temperature of the resin but sufficient to promote further curing and increase the glass transition temperature thereof to the ultimate glass transition temperature of the resin. The temperature of exposure is generally increased at a rate which maintains the temperature within 20°C below the glass transition temperature of the thermosettable resin, so that cure of the resin proceeds in the glassy state. The pressure during the process is generally maintained below 3.4 atmosphere and is preferably atmospheric pressure. The process enables the production of thermoset composite articles suitable for high-performance applications without lengthy autoclave treatments.
摘要:
A composition is provided comprising an epoxy resin and an aromatic amine curing agent, having the formula in which each R is selected C₂-C₇ alkyl and each R′ is selected from C₁-C₇ alkyl. The described composition has good physical properties for high-performance composite applications and has a relatively long working life.