Monsanto Research Corporation

James L Schwendeman

Ival O Salyer

Charles E McClung

Robert T Jefferson

Shih-ming Sun

In a process for rapidly producing a substantially uniform, elongated, cellular thermoplastic article comprising rapidly discharging from a vessel a pressurized gel of a solid thermoplastic amorphous polymer and a gaseous solvent in an amount in the range of from about 25-100% by weight of said polymer, said solvent being capable of forming a flowable gel with the polymer when subjected to superatomospheric pressure, the improvement for shaping the article comprising restraining sufficiently the speed of flow of the gel from the vessel through a die to form the desired shaped article with the gel at ambient temperature in said vessel.

Process for making instant shaped foams

A process for rapidly producing a substantially uniform, solid, cellular thermoplastic article comprising the steps of: (a) charging a vessel with (1) a solid thermoplastic polymer, (2) a solvent mixture the amount of which in the range of from about 25-50% by weight of said polymer boils at or below 0.degree.C. and to prevent shrinkage the minor amount of which in the range of from about 3-30% by weight of said polymer boils at or near 20.degree.C., said solvent mixture being capable of forming a gel with the polymer when subjected to super-atmospheric pressure, (3) water in sufficient amount to lubricate the flow of the gel from the vessel as specified in step (c) below, and (4) for homogeneous polymer solutions a nucleating agent selected from the group consisting of spherical polyethylene powder, glass hollow spheres, phenolic hollow spheres and mixtures thereof; (b) subjecting the contents of the vessel to super-atmospheric pressure at a temperature in the range of room temperature to below the critical temperature of said solvent mixture for a time sufficient to form a flowable gel; and, (c) thereafter rapidly opening an outlet at the bottom of the vessel to cause the gel to flow from the vessel and form the cellular article. Foamable compositions usable in the process to make the cellular articles are described. Major means more than 50% by weight of the solvent mixture and minor means less than 50% by weight of the solvent mixture as the terms imply.

Use of solvent mixtures in making foamable compositions

Aqueous foamable compositions can be used to suppress coal dust, especially respirable coal dust, i.e., coal dust having particle size less than about 10 microns. These compositions are composed principally of water with a minor amount of an interpolymer of:

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Dayton, OH, United States of America

James L Schwendeman