US3959237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sustained release polymers
Assignee: Hydrophilics International Inc
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Filing: 1972-08-11
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Granted: 1976-05-25
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Expires: 1992-08-11
Abstract
Abstract A copolymer derived from a monomeric mixture comprising from 20 to 60 parts of acrylic or methacrylic acid, from 20 to 70 parts of a lower alkyl acrylate or methacrylate, and from 5 to 20 parts of a plasticizing monomer is at least partially neutralized by multivalent cations.
Inventors
- 👤 Izhak Blank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:49
CPC Classifications
C; C08; C08L; C08L33/00; C08L33/02; A; A01; A01N; A01N25/00; A01N25/08; A01N25/10; A61; A61K; A61K9/00; A61K9/0012; A61K9/0048; A61K9/0051; A61K9/70; A61K9/7007; B; B29; B29D; B29D11/00; B29D11/02; C08F; C08F220/00; C08F220/02; C08F220/04; C08F220/06; C08F8/00; C08F8/30; C08F8/44; Y; Y10; Y10S; Y10S526/00; Y10S526/936
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
113 words
A water soluble copolymer consisting essentially of from 20 to 60 parts of at least one member selected from the class consisting of acrylic acid and methacrylic acid, from 20 to 70 parts of at least one member selected from the class consisting of lower alkyl acrylates and lower alkyl methacrylates, and from 5 to 20 parts of a long chain ester of acrylic or methacrylic acid, said chain having from 8 to 18 carbon atoms, said copolymer having a molecular weight of more than one million as determined by its intrinsic viscosity in methylethyl ketone at 25°C, in which at least 25% of the acid groups have been neutralized by multi-valent cations.
Claim 2
Dependent Claim
113 words
A water soluble copolymer consisting essentially of from 20 to 60 parts of at least one member selected from the class consisting of acrylic acid and methacrylic acid, from 20 to 70 parts of at least one member selected from the class consisting of lower alkyl acrylates and lower alkyl methacrylates, and from 5 to 20 parts of a long chain ester of acrylic or methacrylic acid, said chain having from 8 to 18 carbon atoms, said copolymer having a molecular weight of more than one million as determined by its intrinsic viscosity in methylethyl ketone at 25°C, in which at least 25% of the acid groups have been neutralized by multi-valent cations.
Claim 3
Dependent Claim
25 words
The copolymer of claim 1 containing from 20 to 60 parts of a member selected from the class consisting of lower alkyl acrylates and methacrylates.
Claim 4
Dependent Claim
13 words
The copolymer of claim 2 having from 25 to 50 parts methyl methacrylate.
Claim 5
Dependent Claim
17 words
The copolymer of claim 1 wherein from 25 to 75% of the acid groups have been neutralized.
Claim 6
Dependent Claim
20 words
The copolymer of claim 1 wherein the multivalent cations are ions selected from the class consisting of zinc and copper.
Claim 7
Dependent Claim
27 words
The copolymer of claim 5 wherein the neutralization is effected by at least one member selected from the class consisting of zinc ammonium and copper ammonium compounds.
Claim 8
Dependent Claim
13 words
The copolymer of claim 1 having from 40 to 60 parts acrylic acid.
Claim 9
Dependent Claim
18 words
The copolymer of claim 1 wherein the long-chain ester of acrylic acid or methacrylic acid is ethylhexyl acrylate.
References Cited (Backward Citations)
US3113867A
Cited
US3317493A
Cited
US3431226A
Cited
US3577517A
Cited
US3779952A
Cited
US3764587A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-25 | 1979-11-24 | 1980-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-25 | 1983-11-24 | 1984-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-25 | 1987-11-24 | 1988-05-25 | $7700.00 | Window Closed / Lapsed |