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US 5,710,188 AGranted
PVC foam compositions
AssigneeMorton International, Inc.
InventorsGeorge F. Beekman, Lionel R. Price
Life of this patent
Estimating the term…
Abstract
The density of rigid foamed articles made by the thermal decomposition of a blowing agent in a vinyl chloride polymer is reduced by the use of an organotin halide in combination with a mercaptocarboxylic acid ester or a sulfide of such ester or a mixture of the ester and the sulfide to activate the blowing agent.
Claims8
A method for foaming a vinyl chloride polymer comprising heating a mixture comprising the polymer, a blowing agent, an an organotin halide having the formula:
- R.sub.(4-x) SnX.sub.x I
- wherein R is an alkyl radical having from 1 to 18 carbon atoms, and X is halogen of atomic weight 35 to 127, and x is from 1 to 3;
- and
- at least one stabilizer selected from the group consisting of:
- (A) an organotin mercaptide of a mercaptocarboxylic acid ester having the formula:
- R.sup.1.sub.(4-y) SnSZ(COOR.sup.2).sub.m !.sub.y II
- wherein R.sup.1 is an alkyl or cycloalkyl group having from 1 to 30 carbon atoms, Z is a alkylene radical group derived from an alcohol having from 1 to 4 hydroxyl groups and from 1 to 30 carbon atoms, m is an integer from 1 to 4, and y is any number from 1 to 3;
- with the proviso that when y is less than 3, the R.sup.1 groups may be the same or different, and when m is more than 1, the R.sup.2 groups may be the same or different, and
- (B) a sulfide of an organotin mercaptide of Formula II.
6 more elements
Dependencies are inferred from the claim text.