Process for forming microcellular structures having an integral skin and products thereof
AssigneeUrethane Technologies, Inc.
InventorsThomas Roy McClellan, John T. Mizulo, Edwin S. Nelson, Grant R. Pato
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Abstract
Shaped microcellular structures having substantially non-cellular skins are produced from reactive liquid polymer systems incorporating thermoplastic microspheres containing volatile materials such as low boiling point halogenated or non-halogenated organic materials. Use of thermoplastic microspheres encapsulating such volatile materials facilitates the removal of the shaped foamed structure from molds, eliminating the need for release agents. Various products based on this process, such as bathroom fixtures, bicycle and wheel chair tires, shoe soles, and automotive parts, are provided.
Claims24
A process for preparing microcellular structures having substantially non-cellular skins comprising:
- providing a non-aqueous reactive polymer-forming system;
- suspending in said polymer-forming system a material which functions as a combined nonaqueous blowing agent and release agent, said material consisting of a plurality of thermoplastic microspheres encapsulating a volatile material and wherein no additional blowing agents and/or release agents are included;
- said microspheres having a diameter of about 5 .mu.m to 15 .mu.m and an expansion initiation temperature of about 80.degree. C. to 130.degree. C.;
- contacting at least a portion of said plurality of thermoplastic microspheres with a shaping surface at a temperature between about 40% and 90% of said expansion initiation temperature;
- and
- polymerizing said reactive polymer-forming system in which said plurality of thermoplastic microspheres is suspended, to produce a microcellular structure having a substantially non-cellular skin which is readily released from said shaping surface.
Dependencies are inferred from the claim text.