Cook Composites & Polymers Co.

L Scott Crump

Ming Yang Zhao

Chih-Pin Hsu

Erwoan Pezron

Ming-Yang Zhao

A coating may be incorporated in a molded composite article made via a process in which neither the coating nor the resin contact the mold surface. A multilayer sandwich structure is formed having two outside layers of flexible membranes, typically made of silicon. An interior dissolvable film is disposed between the two outer flexible membranes. A layer of fiber reinforcement is disposed between the dissolvable film and one of the flexible membranes. A coating is distributed between a flexible membrane and the dissolvable film, opposite the side having the reinforcement, wherein the film is only slowly soluble, or insoluble, in the coating. The coating is allowed to at least partially cure and a resin is infused through the reinforcement wherein the dissolvable film rapidly dissolves in the resin. The sandwich structure is formed around a mold and the resin is allowed to cure.

In-mold coating by a multiple step infusion process

A low viscosity (and therefore low VOC) resin can be produced by limiting the molar ratio of the reactants, especially the dicarboxylic acid compound, used in the reaction. Specifically, reacting a reaction mixture comprising (i) one mole of a diepoxide having at least two glycidyl ether type epoxy groups; (ii) 0.5 to 2.0 moles of an unsaturated monocarboxylic acid; (iii) 0.1 to 0.5, preferably 0.1 to 0.3, moles of maleic anhydride; and, (iv) water, until substantially all of the epoxy groups disappear leads to the formation of a resin with a high shear (at least 500 s) viscosity of less than 1200 cP when measured in a 70% NVM (non-volatile matter) styrene solution. The resin may be used in barrier coatings, gel coatings, skin coatings and as a laminate resin.

Low VOC vinylester resin and applications

A low tack, low VOC gel coat is disclosed comprising a unsaturated polyester resin derived from maleic anhydride and up to about 30% of an organic solvent. The resin is characterized by: a viscosity of less than or equal to about 1750 cp at 70% NVM in styrene; a glass transition temperature greater than or equal to about 11&deg; C.; and a weight average molecular weight less than or equal to about 6,050. A process for making such a gel coat is also disclosed.

Low VOC low tack gel coat resin

An improved two-stage process for the preparation of polyester resins is provided which involves an initial reaction of a dicarboxylic acid such as isophthalic acid with an alkylene oxide such as ethylene or propylene oxide in the presence of a catalyst to form an oligoester reaction mixture, followed by a second stage reaction between the oligoester reaction mixture and a dibasic acid or anhydride; a first-stage catalyst is employed which has a thermal decomposition temperature substantially at or below the second-stage reaction temperature. The most preferred first-stage catalyst is benzyltriethylammonium chloride.

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Gladstone, MO, United States of America

L Scott Crump