US4332710A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal coagulation of polyurethane dispersions
Assignee: NORWOOD INDUSTRIES Inc A CORP OF PA
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Filing: 1981-02-17
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Granted: 1982-06-01
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Expires: 2001-02-17
Abstract
Abstract An aqueous polyurethane composition capable of thermal coagulation is disclosed. The polyurethane composition is comprised of an aqueous polyurethane dispersion having anionic groups covalently bonded to the polymer chain and solubilized by the addition of a cationic compound which forms a salt with the anionic group. The composition also includes a compound which, when heated in an aqueous solution, generates acid which causes displacement of the cationic compound from the covalently bonded anionic groups. A method of forming a composite sheet material is also disclosed. The composite sheet material is formed by impregnating a porous sheet material with the polyurethane composition and heating the impregnant to generate acid causing coagulation of the polyurethane dispersion in the porous sheet material. The impregnant is dried to form a composite sheet material.
Inventors
- 👤 John McCartney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:27
CPC Classifications
C; C08; C08L; C08L75/00; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0804; C08G18/0819; C08G18/0823
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
68 words
An aqueous polyurethane composition capable of coagulation by the application of heat thereto comprising: an aqueous anionic polyurethane dispersion having anionic groups covalently bonded to the polymer chain and solubilized by the addition of a cationic compound which forms a salt with the anionic group; and a compound which, when heated in an aqueous solution, generates acid which displaces the cationic compound from the covalently bonded anionic group.
Claim 2
Dependent Claim
68 words
An aqueous polyurethane composition capable of coagulation by the application of heat thereto comprising: an aqueous anionic polyurethane dispersion having anionic groups covalently bonded to the polymer chain and solubilized by the addition of a cationic compound which forms a salt with the anionic group; and a compound which, when heated in an aqueous solution, generates acid which displaces the cationic compound from the covalently bonded anionic group.
Claim 3
Dependent Claim
21 words
The polyurethane composition of claim 1 wherein said polyurethane dispersion has a solids content of 5 to 50 percent by weight.
Claim 4
Dependent Claim
21 words
The polyurethane composition of claim 2 wherein said polyurethane dispersion has a solids content of 10 to 40 percent by weight.
Claim 5
Dependent Claim
18 words
The polyurethane composition of claim 1 wherein said polyurethane dispersion has a viscosity of 10 to 5,000 centipoise.
Claim 6
Dependent Claim
18 words
The polyurethane composition of claim 4 wherein said polyurethane dispersion has a viscosity of 10 to 5,000 centipoise.
Claim 7
Dependent Claim
15 words
The polyurethane composition of claim 1 wherein said polyurethane dispersion is a crosslinked polyurethane dispersion.
Claim 8
Dependent Claim
20 words
The polyurethane composition of claim 1 wherein the compound which, when heated, generates acid is a salt of hydrofluorosilicic acid.
Claim 9
Dependent Claim
24 words
The polyurethane composition of claim 7 wherein said salt of hydrofluorosilicic acid is selected from the group consisting of sodium silicofluoride and potassium silicofluoride.
Claim 10
Dependent Claim
34 words
The polyurethane composition of claim 1 wherein said compound which, when heated, generates acid is present at a level wherein there is a stoichiometric excess of acid based upon the anionic covalently bonded groups.
Claim 11
Dependent Claim
21 words
The polyurethane composition of claim 1 including a buffer to maintain the pH of said polyurethane dispersion at 7 to 9.
Claim 12
Dependent Claim
19 words
The polyurethane composition of claim 10 wherein said buffer maintains the pH of said polyurethane dispersion at about 8.5.
Claim 13
Dependent Claim
11 words
The polyurethane composition of claim 10 wherein said buffer is borax.
Claim 14
Dependent Claim
10 words
The polyurethane composition of claim 1 including an alkali hydroxide.
Claim 15
Dependent Claim
48 words
A polyurethane composition comprising an aqueous anionic polyurethane having anionic groups covalently bonded to the polymer chain and solubilized by the addition of a cationic compound which forms a salt with the anionic group; and a sufficient amount of borax to stabilize the pH of the polyurethane dispersion.
Claim 16
Dependent Claim
48 words
A polyurethane composition comprising an aqueous anionic polyurethane having anionic groups covalently bonded to the polymer chain and solubilized by the addition of a cationic compound which forms a salt with the anionic group; and a sufficient amount of borax to stabilize the pH of the polyurethane dispersion.
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) | 1985-05-31 | 1985-11-30 | 1986-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-31 | 1989-11-30 | 1990-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-31 | 1993-11-30 | 1994-06-01 | $7700.00 | Window Closed / Lapsed |