Maturation of polyester compositions for viscosity index control
AssigneeThe Budd Company
InventorsJoseph Norman Epel, Vinod Chandulal Shah, Kenneth Alfred Iseler
Life of this patent
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Abstract
The invention relates to improving the viscosity temperature dependence of a maturated moldable unsaturated polyester resin system, by utilizing a dual thickening system consisting of an oxide or hydroxide of magnesium or calcium and a polyisocyanate, which dual thickening system provides a greatly improved viscosity index, i.e., less viscosity decrease with increase in temperature, thereby providing substantial advantages upon being subjected to temperature increases such as are encountered in molding.
Claims33
A maturated moldable thermosetting resin-containing composition for molding under pressure having a filler selected from the group consisting of (a) reinforcing fiber, (b) inert filler, and (c) a combination of both (a) and (b), dispersed therein, in which the curable resin binder consists essentially of the reaction product, in intimate contact with said filler, of
- A. an unsaturated polyester resin having (1) a ratio of hydroxyl groups to carboxyl groups between about 5.7 and 0.8 and (2) an acid number of at least 14 and (3) an average molecular weight between about 800 and 5,000, and
- B. (1) an organic polyisocyanate in an amount sufficient to react with at least thirty percent but not more than one hundred five percent of the hydroxyl groups present, and
- B. (2) a metallic oxide or hydroxide selected from the group consisting of calcium and magnesium oxides and hydroxides in an amount sufficient to react with at least thirty percent but not more than seventy-five percent of the carboxyl groups present,
- said reaction product containing dispersed therein
- C. an aliphatically-unsaturated monomer,
- D. a free radical polymerization catalyst, and
- E. an internal mold release agent,
- said binder comprising at least about eight weight percent of said composition.
The method of producing a controllable rise in viscosity and an improved viscosity index as herein defined of an uncured polyester compound, said compound comprising:
- (A) an unsaturated polyester resin have (1) a ratio of hydroxyl groups to carboxyl groups between about 5.7 and 0.8 and (2) an acid number of at least 14 and (3) an average molecular weight between about 800 and 5,000;
- at least one (C) aliphatically-unsaturated monomer;
- and (D) a free radical polymerization catalyst, comprising the step of introducing into said polyester resin compound reaction mixture prior to curing (B)(1) an organic polyisocyanate in an amount sufficient to react with at least thirty percent but not more than one hundred five percent of the hydroxyl groups present, and (B)(2) a metallic oxide or hydroxide selected from the group consisting of calcium and magnesium oxides and hydroxides in an amount sufficient to react with at least thirty percent but not more than seventy-five percent of the carboxyl groups present.
In the preparation of a molding compound comprising (A) an unsaturated polyester resin having (1) a ratio of hydroxyl groups to carboxyl groups between about 5.7 and 0.8 and (2) an acid number of at least 14 and (3) an average molecular weight between about 800 and 5,000;
- (C) an aliphatically-unsaturated monomer;
- and (D) a free radical polymerization catalyst, the improvement comprising introducing into said polyester resin compound reaction mixture prior to curing (B)(1) an organic polyisocyanate in an amount sufficient to react with at least thirty percent but not more than one hundred five percent of the hydroxyl groups present, and (B)(2) a metallic oxide or hydroxide selected from the group consisting of calcium and magnesium oxides and hydroxides in an amount sufficient to react with at least thirty percent but not more than seventy-five percent of the carboxyl groups present, thereby to produce a controllable rise in viscosity of said molding compound and an improved viscosity index as herein defined.
Dependencies are inferred from the claim text.