| abstract |
An aqueous sizing composition, glass fiber strands having the dried residue of the aqueous sizing composition and processes for producing these articles are provided that enable the production of glass fiber reinforced polymeric materials having improved properties. In addition, improvements are obtained in the processability of using glass fiber roving in the production of sheet molding compound, bulk molding compound and thick molding compound. The sizing composition, sized glass fiber strands, processes, reinforced polymeric materials and improvements of this invention emanate from the use of epoxidized polar thermoplastic copolymers in aqueous sizing compositions that are substantially insoluble in the matrix polymer. The aqueous sizing composition has one or more cross-linkable film formers, one or more organosilane coupling agents and about 3 to about 12 weight percent of the aqueous sizing composition of the epoxidized polar thermoplastic copolymer. The epoxy copolymer has about 3 to about 10 parts of epoxy functionality per 10 parts of the functionality of the other polymer material in the copolymer. Also the epoxy copolymer has a glass transition temperature (Tg) of from ambient temperature to about 50 DEG C. The sizing composition can also have additional additives like lubricants, plasticizers, emulsifiers, urea formaldehyde condensates, and the like. The aqueous sizing composition is applied to glass fibers during their formation, and the sized glass fibers are gathered into strands and dried. A plurality of the dried, sized glass fiber strands are gathered, dried and collected for use as reinforcement in polymeric materials. |