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US4481326A Expired / Lapsed US ⏱️ 0.0 years remaining

Water soluble films of polyvinyl alcohol polyvinyl pyrrolidone

Assignee: Colgate Palmolive Co
•
Filing: 1983-07-26
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Granted: 1984-11-06
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Expires: 2003-07-26
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Abstract

Abstract Films which are rapidly soluble in cold and warm water are formed from blends of water soluble polyvinyl alcohol (partially hydrolyzed polyvinyl acetate) and polyvinyl pyrrolidone. The polymers are compatible and form homogeneous mixtures from which clear, transparent, non-tacky, easily handleable, mechanically strong films can be formed. The films are stable at both low and high humidity conditions, i.e., the films do not become brittle or tacky and retain their high rates of dissolution in water even after being stored in low or high humidity environments at both high and low temperatures. Further, improvements are achieved by incorporating a plasticizer into the polymer blend. The films are also heat sealable and biodegradable.

Inventors

  • 👤 Gerard G. Sonenstein

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 16:24
CPC Classifications
C; C08; C08L; C08L29/00; C08L29/02; C08L29/04; C08L39/00; C08L39/04; C08L39/06

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 59 words
A water soluble coherent self-supporting film comprising a uniform mixture of water soluble polyvinyl alcohol, namely 79-95% hydrolyzed polyvinylacetate, and polyvinyl pyrrolidone wherein both of said polymers have weight average molecular weights in the range of about 10,000 to 50,000, the weight ratio of polyvinyl alcohol to polyvinyl pyrrolidone being in the range of from 10:1 to about 1:1.
Claim 2
Dependent Claim 59 words
A water soluble coherent self-supporting film comprising a uniform mixture of water soluble polyvinyl alcohol, namely 79-95% hydrolyzed polyvinylacetate, and polyvinyl pyrrolidone wherein both of said polymers have weight average molecular weights in the range of about 10,000 to 50,000, the weight ratio of polyvinyl alcohol to polyvinyl pyrrolidone being in the range of from 10:1 to about 1:1.
Claim 3
Dependent Claim 14 words
The water soluble film of claim 1 wherein the weight ratio is about 4:1.
Claim 4
Dependent Claim 60 words
The water soluble film of claim 1 wherein the polyvinyl alcohol has a degree of hydrolysis in the range of from about 85% to about 90% and a weight average molecular weight in the range of from about 20,000 to about 40,000 and the polyvinyl pyrrolidone has a molecular weight in the range of from about 20,000 to about 50,000.
Claim 5
Dependent Claim 58 words
The water soluble film of claim 1 wherein the polyvinyl alcohol has a degree of hydrolysis in the range of from about 86 to 89% and a weight average molecular weight in the range of from about 22,000 to 31,000 and the polyvinyl pyrrolidone has a molecular weight in the range of from about 30,000 to about 45,000.
Claim 6
Dependent Claim 17 words
The water soluble film of claim 1 which further comprises a plasticizer for the polyvinyl alcohol component.
Claim 7
Dependent Claim 16 words
The water soluble film of claim 5 in which the plasticizer is tetraethylene glycol or polyglycerol.

References Cited (Backward Citations)

US3892905A Cited
US3997489A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-11-06 1988-05-07 1988-11-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-11-06 1992-05-07 1992-11-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-11-06 1996-05-07 1996-11-06 $7700.00 Window Closed / Lapsed

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