Glass sizing composition
View Patent ↗The present invention relates to a sizing composition for use on glass fibers which are used to reinforce plastic resins used in the formation of fiber-reinforced plastics (FRPs). The sizing composition comprises a copolymer formed from at least one functional monomer that is selected from the group consisting of hydroxy, phenyl and alkoxylated functional groups. The glass fibers sized with the sizing composition of the invention have excellent computability with resins used in forming FRPs, as seen by a low level of white glass.
1. A fiber-reinforced plastic comprising a plastic resin and glass fibers, where the plastic resin is selected from the group consisting of epoxy, epoxy novalac resin, and low-styrene epoxy resins, and wherein said glass fibers have directly coated thereon a film-forming functional copolymer composition comprising:
a) 0.1 to 30 percent by weight of functional monomer units selected from the group consisting of hydroxyl functional monomer units, phenyl functional monomer units, alkoxylated functional monomer units, and mixtures thereof, wherein the alkoxylated functional monomer has a group with the formula —(RO) n —where R is a methyl, ethyl, propyl or butyl group, or a mixture thereof, and n is from 1 to 50; and
b) 70 to 99.9 percent by weight of one or more non-functional ethylenically unsaturated monomer units, wherein said functional polymer has a molecular weight of greater than 55,000,
wherein said fiber-reinforced plastic exhibits less white glass as compared with a like fiber-reinforced plastic which contains glass fiber which is sized with a like film-forming composition without said functional monomer units.
2. A fiber-reinforced plastic comprising glass fibers and a plastic matrix resin selected from the group consisting of epoxy, epoxy novolac resins, and low-styrene epoxy resins, wherein said glass fibers are sized with a film-forming functional copolymer composition comprising:
c) 0.1 to 30 percent by weight of phenyl functional monomer units; and
d) 70 to 99.9 percent by weight of one or more non-functional ethylenically unsaturated monomer units.
3. The fiber-reinforced plastic of claim 2 , wherein the phenyl functional monomer units comprise phenoxyethyl (meth) acrylate.
4. The fiber-reinforced plastic of claim 2 , wherein the functional polymer has a molecular weight of greater than 55,000.