Stabilization of vinyl resin foam systems

Claim 2

IN THE PROCESS OF FOAMING A VINYL CHLORIDE RESIN PLASTISOL CONTAINING A CHEMICALLY HEAT DECOMPOSABLE BLOWING AGENT THE IM SITION A CELL STABLIZER LIQUID, ON THE BASIS OF CONTAINED DISSOLVED SOLIDS, IN AN AMOUNT IN THE RANGE HOF 0.05 TO 2.0 PARTS BY WEIGHT PER 100 PARTS BY WEIGHT OF FUSIBLE VINYL CHLORIDE RESIN, SAID STABILIZER CONSISTING OF THE TOTAL PRODUCT OF THE REACTION, AT POLYMERIZATION CONDITIONS, OF A PRECURSOR COMPOSITION OF AT LEAST ONE MONOMERIC METHACRYLATE ESTER OF METHACRYLIC ACID WITH AC3 TO C5 ALCOHOL; A CHAIN TRANSFER AGENT SELECTED FROM THE GROUP CONSISTING OF DIBUTYL MALEATE AND DIBUTYL FUMARATE; AN INITIATOR; AND SOLVENT, SAID SOLVENT BEING PRESENT IN AN AMOUNT AT LEAST SUFFICIENT FOR SOLVATION OF PRECURSORS AND PRODUCT TO AN AMOUNT EQUAL TO AND NO GREATOR THAN 2 TIMES THE WEIGHT OF MONOMERIC METHACRYLATE ESTER, AND SAID SOLVENT BEING NON-REACTIVE IN THE PRECURSOR COMPOSITION, IN THE ABSENCE OF SAID INITIATOR, WHEREIN SAID PRECURSOR COMPOSITION CONSISTS OF 0.1 TO 20 PARTS BY WEIGHT OF CHAIN TRANSFER AGENT AND 0.05 TO 2.0 PARTS BY WEIGHT OF INITIATOR PER 100 PARTS BY WEIGHT OF THE MONOMER METHACRYLATE ESTER, AND WHEREIN THE SEPARABLE POLYMERIC MATERIAL PRODUCED FROM SAID TOTAL PRODUCT OF REACTION HAS AN INTRINSIC VISCOSITY, MEASURED AT 30*C. IN CHCL3, IN THE RANGE OF 0.05 TO 0.35 DECILITERS PER GRAM.

Claim 3

In the process of foaming a vinyl chloride resin plastisol containing a chemically heat decomposable blowing agent the improvement which comprises adding to said plastisol composition a cell stabilizer liquid, on the basis of contained dissolved solids, in an amount in the range of 0.05 to 2.0 parts by weight per 100 parts by weight of fusible vinyl chloride resin, said stabilizer consisting of the total product of the reaction, at polymerization conditions, of a precursor composition of at least one monomeric methacrylate ester of methacrylic acid with a C3 to C5 alcohol; a chain transfer agent selected from the group consisting of dibutyl maleate and dibutyl fumarate; an initiator; and solvent, said solvent being present in an amount at least sufficient for solvation of precursors and product to an amount equal to and no greater than 2 times the weight of monomeric methacrylate ester, and said solvent being non-reactive in the precursor composition, in the absence of said initIator, wherein said precursor composition consists of 0.1 to 20 parts by weight of chain transfer agent and 0.05 to 2.0 parts by weight of initiator per 100 parts by weight of the monomer methacrylate ester, and wherein the separable polymeric material produced from said total product of reaction has an intrinsic viscosity, measured at 30*C. in CHCl3, in the range of 0.05 to 0.35 deciliters per gram.

Claim 4

In the process of foaming a vinyl chloride resin plastisol containing a chemically heat decomposable blowing agent the improvement which comprises adding to said plastisol composition a cell stabilizer liquid, on the basis of contained dissolved solids, in an amount in the range of 0.05 to 2.0 parts by weight per 100 parts by weight of fusible vinyl chloride resin, said stabilizer consisting of the total product of the reaction, at polymerization conditions, of a precursor composition of at least one monomeric methacrylate ester of methacrylic acid with a C3 to C5 alcohol; a chain transfer agent selected from the group consisting of dibutyl maleate and dibutyl fumarate; an initiator; and solvent, said solvent being present in an amount at least sufficient for solvation of precursors and product to an amount equal to and no greater than 2 times the weight of monomeric methacrylate ester, and said solvent being non-reactive in the precursor composition, in the absence of said initIator, wherein said precursor composition consists of 0.1 to 20 parts by weight of chain transfer agent and 0.05 to 2.0 parts by weight of initiator per 100 parts by weight of the monomer methacrylate ester, and wherein the separable polymeric material produced from said total product of reaction has an intrinsic viscosity, measured at 30*C. in CHCl3, in the range of 0.05 to 0.35 deciliters per gram.

Claim 5

The preparation of foamed cellular bodies in accordance with claim 1 wherein said stabilizer solution is the reaction product of a precursor composition consisting of isobutyl methacrylate as the methacrylate ester, dibutyl maleate as the chain transfer agent, dibenzoyl peroxide as the initiator, and mineral spirits as the solvent.

Claim 6

The preparation of foamed cellular bodies in accordance with claim 2 wherein said precursor composition consists of 100 parts by weight of isobutyl methacrylate, 1.0 to 60 parts by weight of dibutyl maleate, 0.4 to 10.0 parts by weight of dibenzoyl peroxide, and from 100 to 200 parts by weight of mineral spirits.

Claim 7

The preparation of foamed cellular bodies in accordance with claim 3 wherein said precursor composition consists of 100 parts by weight of isobutyl methacrylate, 15.6 parts by weight of dibutyl maleate, 9.0 parts by weight of dibenzoyl peroxide and 102 parts by weight of mineral spirits.

Claim 8

The preparation of foamed cellular bodies in accordance with claim 1 wherein said elevated temperature is above about 500*F.