Low-density polyester resin foams and method of preparation

Claim 1

AN EXPANDABLE LIQUID UNSATURATED POLYESTER RESIN COMPOSITION ADAPTED TO EXPAND AND CURE, BY ITS REACTION EXOTHERM, INTO A LOW-DENSITY POLYESTER RESIN FOAM PRODUCT, HICH COMPOSITION COMPRISES: A. A LIQUID UNSATURATED POLYETER RESIN IN SOLUTION WITH AN ETHYLENICALLY UNSATURATED MONOMER SUBJECT TO CROSS-LINKING BY CATALYSIS WITH A PEROXIDE CATALYST BY ITS OWN REACTION EXOTHERM ON ADDITION OF THE PEROXIDE CATALYST, B. A SULFONYL HYDRAZIDE MOIETY PERSENT IN AN AMOUNT OF FROM ABOUT 0.1 TO 15 PHR AS A FOAMING AGENT; C. A COBALT ACCELERATOR PERSENT IN AN AMOUNT SUFFICIENT TO PROMOTE THE CURE OF THE POLYESTER RESIN, D. A PEROXIDE CATALYST ACTIVATED AT A TEMPERATURE BELOW ABOUT 100*F, WHICH CATALYST IS PERSENT IN AN AMOUNT TO PROVIDE FREE RADICALS ON DECOMPOSITION SUFFICIENT TO CROSS-LINK THE POLYESTER RESIN, AND E. A REDOX AMINE COMPOUND SELECTED FROM THE GROUP CONSISTING OF ALKYL AMINE, ALKANOL AMINES, AMMONIA, ALICYCLIC AMINES, ALKENE AMINES, AN ALKYL-SUBSTITUTED AMINO ALKYL PHENOL, AN ALKYL-SUBSTITUTED HETEROCYCLIC AMINE AND POLY C2-C4 ALKYLENE POLYAMINE, WHICH AMINE COMPOUNDS ARE PRESENT IN AN AMOUNT OF FROM ABOUT 0.01 TO 10 PHR TO PERMIT, DURING THE POLYESTER RESIN REACTION EXOOOTHERM, THE SUBSTANTIAL DECOMPOSITION OF THE FOAMING AGENT TO PRECEDE SELECTIVELY THE EXOTHERMIC GELATION AND CURING OF THE POLYESTER RESIN COMPOSITION.

Claim 13

A method of preparing low-density polyester foams, which method comprises: a. admixing a liquid polyester resin composition which comprises i. a liquid unsaturated polyester resin in solution with an ethylenically unsaturated monomer subject to cross-linking by catalysis with a peroxide catalyst by its own reaction exotherm on addition of the peroxide catalyst, ii. a sulfonyl hydrazide moiety present in an amount of from about 0.1 to 15 phr as a foaming agenT, iii. a cobalt accelerator present in an amount sufficient to promote the cure of the polyester resin, iv. a peroxide catalyst activated at a temperature below about 100*F, which catalyst is present in an amount to provide free radicals on decomposition sufficient to cross-link the polyester resin, and v. a redox amine compound selected from the group consisting of alkyl amines, alkanol amines, ammonia, alicyclic amines, alkene amines, an alkyl-substituted amino alkyl phenol, an alkyl-substituted heterocyclic amine and poly C2-C4 alkylene polyamine, which amine compounds are present in an amount of from about 0.01 to 10 phr to permit, during the polyester resin reaction exotherm, the substantial decomposition of the foaming agent to precede selectively the exothermic gelation and curing of the polyester resin composition; and b. expanding, by the reaction exotherm of the polyester resin composition, the polyester resin composition after admixing of the polyester resin composition components by decomposing all or substantially all of the foaming agent, such decomposition and expansion occurring prior to the gelation of the polyester resin, thereby providing a low-density polyester resin foam product.

Claim 14

A method of preparing low-density polyester foams, which method comprises: a. admixing a liquid polyester resin composition which comprises i. a liquid unsaturated polyester resin in solution with an ethylenically unsaturated monomer subject to cross-linking by catalysis with a peroxide catalyst by its own reaction exotherm on addition of the peroxide catalyst, ii. a sulfonyl hydrazide moiety present in an amount of from about 0.1 to 15 phr as a foaming agenT, iii. a cobalt accelerator present in an amount sufficient to promote the cure of the polyester resin, iv. a peroxide catalyst activated at a temperature below about 100*F, which catalyst is present in an amount to provide free radicals on decomposition sufficient to cross-link the polyester resin, and v. a redox amine compound selected from the group consisting of alkyl amines, alkanol amines, ammonia, alicyclic amines, alkene amines, an alkyl-substituted amino alkyl phenol, an alkyl-substituted heterocyclic amine and poly C2-C4 alkylene polyamine, which amine compounds are present in an amount of from about 0.01 to 10 phr to permit, during the polyester resin reaction exotherm, the substantial decomposition of the foaming agent to precede selectively the exothermic gelation and curing of the polyester resin composition; and b. expanding, by the reaction exotherm of the polyester resin composition, the polyester resin composition after admixing of the polyester resin composition components by decomposing all or substantially all of the foaming agent, such decomposition and expansion occurring prior to the gelation of the polyester resin, thereby providing a low-density polyester resin foam product.