Patent US4601951A successfully refreshed from Google Patents.
US4601951A
Expired / Lapsed
US
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Impregnation of leather with polyurethane dispersions
Assignee: Steon Co
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Filing: 1983-12-05
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Granted: 1986-07-22
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Expires: 2003-12-05
Abstract
Abstract A method of preparing an impregnated leather composite is provided. A low density leather sheet is impregnated with an aqueous ionic dispersion of a polyurethane polymer. The polyurethane polymer which is impregnated in the leather sheet is ionically coagulated from the dispersion. The impregnate is dried to form an impregnated leather composition.
Inventors
- 👤 Paul A. Fertell
- 👤 John McCartney
- 👤 Giandaniele Robbiati
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:19
CPC Classifications
C; C14; C14C; C14C9/00; Y; Y10; Y10S; Y10S428/00; Y10S428/904; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31558
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
56 words
A method of impregnating leather comprising: impregnating a leather sheet by completely saturating the leather sheet to eliminate all voids therefrom with an aqueous ionic dispersion of a polyurethane polymer; ionically coagulating said polyurethane polymer from said dispersion impregnated in said leather sheet; and drying the impregnant to form an impregnated leather having improved tear strength.
Claim 2
Independent Claim
56 words
A method of impregnating leather comprising: impregnating a leather sheet by completely saturating the leather sheet to eliminate all voids therefrom with an aqueous ionic dispersion of a polyurethane polymer; ionically coagulating said polyurethane polymer from said dispersion impregnated in said leather sheet; and drying the impregnant to form an impregnated leather having improved tear strength.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said polyurethane polymer has solubilizing ionizable groups covalently bonded to the polymer chain which are reacted with an ionic dispersing agent.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein said polyurethane polymer has substantially no unreacted N═C═O groups.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said leather is a low density leather.
Claim 6
Dependent Claim
33 words
The method of claim 4 including heating the impregnated low density leather under heat and pressure, said heat and pressure being applied to at least one surface thereof to develop a grain layer.
Claim 7
Dependent Claim
17 words
The method of claim 4 wherein said low density leather is fully impregnated with the polyurethane dispersion.
Claim 8
Dependent Claim
19 words
The method of claim 4 wherein said low density leather has a bulk density of 0.3 to 0.8 g/cc.
Claim 9
Dependent Claim
14 words
The method of claim 4 wherein said low density leather is a leather split.
Claim 10
Dependent Claim
22 words
The method of claim 4 wherein said low density leather is selected from the group consisting of pig skin and sheep skin.
Claim 11
Dependent Claim
21 words
The method of claim 1 including removing substantially all of the dispersing agent from the impregnated sheet prior to said drying.
Claim 12
Dependent Claim
14 words
The method of claim 1 wherein said polyurethane dispersion is coagulated by thermal coagulation.
Claim 13
Dependent Claim
23 words
The method of claim 1 wherein said aqueous ionic polyurethane polymer dispersion has a solids content of 5 to 50 percent by weight.
Claim 14
Dependent Claim
20 words
The method of claim 1 wherein said aqueous ionic polyurethane polymer dispersion has a viscosity of 10 to 5,000 centipoise.
Claim 15
Dependent Claim
21 words
The method of claim 1 wherein said dried impregnant is comprised of up to 40 percent by weight of polyurethane polymer.
Claim 16
Dependent Claim
13 words
The method of claim 1 wherein said dispersion is a crosslinked polyurethane dispersion.
Claim 17
Dependent Claim
18 words
The method of claim 1 wherein said dried impregnant has a bulk density of 0.5 to 1.3 g/cc.
Claim 18
Dependent Claim
73 words
An impregnated leather composite comprised of a leather sheet having an ionically coagulated aqueously ionically solubilized polyurethane polymer impregnated throughout said leather sheet at a level sufficient to improve the tear strength of said leather, said composite having an internal structure attributable to the complete saturation thereof with an impregnant from which said ionically coagulated aqueously ionically solubilized polyurethane is derived, and said composite having a bulk density less that its actual density.
Claim 19
Dependent Claim
73 words
An impregnated leather composite comprised of a leather sheet having an ionically coagulated aqueously ionically solubilized polyurethane polymer impregnated throughout said leather sheet at a level sufficient to improve the tear strength of said leather, said composite having an internal structure attributable to the complete saturation thereof with an impregnant from which said ionically coagulated aqueously ionically solubilized polyurethane is derived, and said composite having a bulk density less that its actual density.
Claim 20
Dependent Claim
16 words
The impregnated leather composite of claim 17 wherein said polyurethane polymer is a crosslinked polyurethane polymer.
Claim 21
Dependent Claim
13 words
The impregnated leather composition of claim 17 having at least one grain layer.
Claim 22
Dependent Claim
19 words
The impregnated leather composition of claim 17 having up to 40 percent by weight of polyurethane polymer impregnated therein.
Claim 23
Dependent Claim
14 words
The impregnated leather composition of claim 17 wherein said leather is low density leather.
Claim 24
Dependent Claim
16 words
The impregnated leather composition of claim 21 wherein the low density leather is a leather split.
Claim 25
Dependent Claim
21 words
The impregnated leather composition of claim 21 wherein the low density leather has a bulk density of 0.3 to 0.8 g/cc.
Claim 26
Dependent Claim
23 words
The impregnated leather composition of claim 21 wherein low density leather is selected from the group consisting of pig skin and sheep skin.
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) | 1989-07-21 | 1990-01-20 | 1990-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-21 | 1994-01-20 | 1994-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-21 | 1998-01-20 | 1998-07-22 | $7700.00 | Window Closed / Lapsed |