Self-release foam laminate
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
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Jun 23, 1987
Grant Date -
N/A
app pub date -
May 19, 1986
filing date -
May 19, 1986
priority date (Note) -
Expired
status (Latency Note)
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Abstract
A method of mechanically frothing and casting an aqueous polyurethane dispersion yields a foam which, when rolled, wound or stacked, is self-releasing from the pressure sensitive adhesive layer co-cured therewith. The method includes admixing an aqueous ionic polyurethane dispersion with a stearate stabilizer and an optional aziridine crosslinking agent, frothing and casing the admixture, and co-curing the resultant foam sheet with a pressure sensitive adhesive layer. Before frothing, the polyurethane dispersion contains particles having an average size of less than one micron, and contains between 35 and 70 percent by weight of the polyurethane dispersion, between 13 and 50 percent by weight of a 33 percent by weight dispersion of a stearate salt, and up to 33 percent by weight of polyfunctional aziridine. The foam produced from the frothed admixture provides a substrate with which an uncured pressure sensitive adhesive can firmly co-cure but to which the cured adhesive demonstrates readily removable adhesion. The laminate of the foam with a pressure sensitive adhesive thus provides either a medical dressing, or a general purpose tape for industrial use, which may be stacked or self-wound without release paper.
First Claim
Other Claims data not available