Patent US4526581A successfully refreshed from Google Patents.
US4526581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing leather
Assignee: Rohm and Haas Co
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Filing: 1983-02-07
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Granted: 1985-07-02
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Expires: 2003-02-07
Abstract
Abstract This invention is directed to an improved process for producing leather and products resulting thereby. The process employs methacrylic acid/alkyl acrylate copolymers having a narrow range of molecular weight and produces leather which is flexible, with a smooth grain and well-filled and which is resistant to detannage by washing with alkaline solution.
Inventors
- 👤 William C. Prentiss
- 👤 David N. Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:06
CPC Classifications
C; C14; C14C; C14C3/00; C14C3/02; C14C3/08; C14C3/18; C14C3/22
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
59 words
In a process for producing leather the use as a tanning agent of a copolymer comprising at least 60 mole percent of residues of methacrylic acid and at least about 5 mole percent of residues of at least one (C 1 -C 4 ) alkyl acrylate, said copolymer having a weight average molecular weight from about 3500 to 9000.
Claim 2
Dependent Claim
59 words
In a process for producing leather the use as a tanning agent of a copolymer comprising at least 60 mole percent of residues of methacrylic acid and at least about 5 mole percent of residues of at least one (C 1 -C 4 ) alkyl acrylate, said copolymer having a weight average molecular weight from about 3500 to 9000.
Claim 3
Dependent Claim
29 words
The process of claim 2 wherein the copolymer comprises from about 5 to 40 mole percent of residues of at least one (C 1 -C 4 ) alkyl acrylate.
Claim 4
Dependent Claim
28 words
The process of claim 2 wherein the copolymer consists essentially of residues of methacrylic acid and from about 5 to 30 mole percent of residues of methyl acrylate.
Claim 5
Dependent Claim
28 words
The process of claim 2 wherein the copolymer consists essentially of residues of methacrylic acid and from about 5 to 25 mole percent of residues of ethyl acrylate.
Claim 6
Dependent Claim
28 words
The process of claim 2 wherein the copolymer consists essentially of residues of methacrylic acid and from about 5 to 15 mole percent of residues of butyl acrylate.
Claim 7
Dependent Claim
21 words
The process of claim 2 wherein the weight average molecular weight of the copolymer is from about 4000 to about 7500.
Claim 8
Dependent Claim
21 words
The process of claim 3 wherein the weight average molecular weight of the copolymer is from about 4000 to about 7500.
Claim 9
Dependent Claim
21 words
The process of claim 4 wherein the weight average molecular weight of the copolymer is from about 4000 to about 7500.
Claim 10
Dependent Claim
21 words
The process of claim 5 wherein the weight average molecular weight of the copolymer is from about 4000 to about 7500.
Claim 11
Dependent Claim
8 words
The product of the process of claim 1.
Claim 12
Dependent Claim
8 words
The product of the process of claim 2.
Claim 13
Dependent Claim
8 words
The product of the process of claim 3.
Claim 14
Dependent Claim
8 words
The product of the process of claim 4.
Claim 15
Dependent Claim
8 words
The product of the process of claim 5.
Claim 16
Dependent Claim
8 words
The product of the process of claim 6.
Claim 17
Dependent Claim
8 words
The product of the process of claim 7.
Claim 18
Dependent Claim
8 words
The product of the process of claim 8.
Claim 19
Dependent Claim
8 words
The product of the process of claim 9.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-01 | 1992-12-31 | 1993-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-01 | 1996-12-31 | 1997-07-02 | $7700.00 | Window Closed / Lapsed |