US4269748A
Expired / Lapsed
US
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Process for the preparation of aqueous polyurethane dispersions and solutions
Assignee: Bayer AG
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Filing: 1979-03-02
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Granted: 1981-05-26
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Expires: 1999-03-02
Abstract
Abstract The present invention relates to a process for the preparation of aqueous solutions or dispersions of polyurethanes, in which process prepolymers which have at least two free isocyanate groups and contain chemically-fixed hydrophilic groups and/or external emulsifiers which are not chemically fixed are reacted with chain lengthening agents in the aqueous phase, characterized in that the isocyanate prepolymer which is hydrophilically modified and/or contains an external emulsifier is mixed with chain lengthening agents selected from the group consisting of azines and hydrazones in the absence of water and the mixture obtained is then mixed with water. The present invention also relates to the dispersions or solutions which can be obtained by this process. Lastly, this invention relates to the use of the dispersions or solutions which can be obtained by this process for coating flexible substrates.
Inventors
- 👤 Klaus Nachtkamp
- 👤 Josef Pedain
- 👤 Jurgen Grammel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:36
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/2805; C08G18/2815; C08G18/283; C08G18/08; C08G18/0804; C08G18/10; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
91 words
A process for the preparation of aqueous solutions or dispersions of polyurethanes prepared by the reaction of prepolymers which have at least two free isocyanate groups and contain either chemically fixed hydrophilic groups and/or external emulsifiers which are not chemically fixed, with chain lengthening agents in the aqueous phase, characterized in that the isocyanate prepolymer which is hydrophilically modified and/or contains an external emulsifier is mixed with azine chain lengthening agents in the absence of water, and the resulting mixture is then mixed with water before significant increases in viscosity occur.
Claim 2
Dependent Claim
91 words
A process for the preparation of aqueous solutions or dispersions of polyurethanes prepared by the reaction of prepolymers which have at least two free isocyanate groups and contain either chemically fixed hydrophilic groups and/or external emulsifiers which are not chemically fixed, with chain lengthening agents in the aqueous phase, characterized in that the isocyanate prepolymer which is hydrophilically modified and/or contains an external emulsifier is mixed with azine chain lengthening agents in the absence of water, and the resulting mixture is then mixed with water before significant increases in viscosity occur.
Claim 3
Dependent Claim
47 words
The process according to claim 1, characterized in that the nature and proportions of the reactants are chosen to provide from about 0.25 to 1.5 isocyanate-reactive, at least partially blocked hydrazinic-NH 2 groups of the chain lengthening agent for each isocyanate group of the isocyanate group-containing prepolymer.
Claim 4
Dependent Claim
8 words
Dispersions or solutions obtainable according to claim 1.
Claim 5
Dependent Claim
18 words
Coatings prepared by a process which comprises applying the solutions or dispersions of claim 1 to a substrate.
Claim 6
Dependent Claim
10 words
Films prepared from the solutions or dispersions of claim 1.
Claim 7
Dependent Claim
10 words
Lacquers prepared from the solutions or dispersions of claim 1.
Claim 8
Dependent Claim
170 words
A process for the preparation of aqueous solutions or dispersions comprising (A) mixing in the absence of water (i) a hydrophilic isocyanate prepolymer having (a) an average isocyanate functionality of from about 1.8 to 2.2; (b) its hydrophilic properties contributed by dispersing centers selected from the group consisting of chemically incorporated cationic or anionic groups present in from about 0 to 100 milliequivalents per 100 g of isocyanate prepolymer, chemically incorporated ethylene oxide units present in the isocyanate prepolymer in from about 0 to 30% by weight, based on the weight of the isocyanate prepolymer, and external emulsifiers present in about 0 to 30% by weight, based on the weight of the isocyanate prepolymer; and (c) an average molecular weight of from about 500 to 10,000 (ii) with an azine chain lengthening agent which forms hydrazine under the hydrolytic influence of water to form a mixture and (B) mixing the mixture of (A), before significant increases in viscosity occur, with water to release the hydrazine and chain lengthen the prepolymer.
Claim 9
Dependent Claim
170 words
A process for the preparation of aqueous solutions or dispersions comprising (A) mixing in the absence of water (i) a hydrophilic isocyanate prepolymer having (a) an average isocyanate functionality of from about 1.8 to 2.2; (b) its hydrophilic properties contributed by dispersing centers selected from the group consisting of chemically incorporated cationic or anionic groups present in from about 0 to 100 milliequivalents per 100 g of isocyanate prepolymer, chemically incorporated ethylene oxide units present in the isocyanate prepolymer in from about 0 to 30% by weight, based on the weight of the isocyanate prepolymer, and external emulsifiers present in about 0 to 30% by weight, based on the weight of the isocyanate prepolymer; and (c) an average molecular weight of from about 500 to 10,000 (ii) with an azine chain lengthening agent which forms hydrazine under the hydrolytic influence of water to form a mixture and (B) mixing the mixture of (A), before significant increases in viscosity occur, with water to release the hydrazine and chain lengthen the prepolymer.
Claim 10
Dependent Claim
111 words
The process of claim 7 wherein the hydrophilic isocyanate prepolymer has (a) an average isocyanate functionality of about 2, (b) its hydrophilic properties contributed by dispersing centers selected from the group consisting of chemically incorporated cationic or anionic groups present in from about 0.1 to 100 milliequivalents per 100 g of isocyanate prepolymer, chemically incorporated ethylene oxide units present in the isocyanate prepolymer in from about 0.5 to 30% by weight, based on the weight of the isocyanate prepolymer, and external emulsifiers present in from about 1 to 30% by weight, based on the weight of the isocyanate prepolymer, and (c) an average molecular weight of from about 800 to 4000.
Claim 11
Dependent Claim
75 words
The process of claim 7 wherein the azines have the formula ##STR2## wherein R 1 , R 2 , R 3 and R 4 , which may be the same or different, represent hydrogen, aliphatic hydrocarbon groups having from 1 to 17 carbon atoms, or R 1 and R 2 and/or R 3 and R 4 , together with the >C═ carbon atom, may form a cycloaliphatic ring having from 5 to 18 carbon atoms.
Claim 12
Dependent Claim
35 words
The process of claim 7 wherein the equivalent ratio of isocyanate groups of hydrophilic isocyanate prepolymer (i) to free and blocked hydrazinic-NH 2 -groups of chain lengthening agent (ii) is from about 4:1 to 1:1.5.
Claim 13
Dependent Claim
27 words
The process of claim 7 wherein hydrophilic isocyanate prepolymer (i) is mixed with chain lengthening agent (ii) at a temperature of from about -20° to 100° C.
Claim 14
Dependent Claim
40 words
The process of claim 11 wherein hydrophilic isocyanate prepolymer (i) is mixed with chain lengthening agent (ii) in the presence of up to about 30% by weight of an organic solvent, based on the weight of the hydrophilic isocyanate prepolymer.
Claim 15
Dependent Claim
44 words
The process of claim 7 wherein the mixture of hydrophilic isocyanate prepolymer (i) and chain lengthening agent (ii) is mixed with a sufficient quantity of water to produce a solution or dispersion having a solids content of from about 40 to 60% by weight.
Claim 16
Dependent Claim
19 words
The process of claim 13 wherein the water is at a temperature of from about 0° to 90° C.
Claim 17
Dependent Claim
13 words
The aqueous polyurethane solutions or dispersions produced by the process of claim 7.
Claim 18
Dependent Claim
91 words
A process for the preparation of aqueous solutions or dispersions of polyurethanes prepared by the reaction of prepolymers which have at least two free isocyanate groups and contain either chemically fixed hydrophilic groups and/or external emulsifiers which are not chemically fixed, with chain lengthening agents in the aqueous phase, characterized in that the isocyanate prepolymer which is hydrophilically modified and/or contains an external emulsifier is mixed with hydrazone chain lengthening agents in the absence of water, and the resulting mixture is then mixed with water, before significant increases in viscosity occur.
Claim 19
Dependent Claim
91 words
A process for the preparation of aqueous solutions or dispersions of polyurethanes prepared by the reaction of prepolymers which have at least two free isocyanate groups and contain either chemically fixed hydrophilic groups and/or external emulsifiers which are not chemically fixed, with chain lengthening agents in the aqueous phase, characterized in that the isocyanate prepolymer which is hydrophilically modified and/or contains an external emulsifier is mixed with hydrazone chain lengthening agents in the absence of water, and the resulting mixture is then mixed with water, before significant increases in viscosity occur.
Claim 20
Dependent Claim
174 words
A process for the preparation of aqueous solutions or dispersions comprising: (A) mixing in the absence of water (i) a hydrophilic isocyanate prepolymer having (a) an average isocyanate functionality of from about 1.8 to 2.2; (b) its hydrophilic properties contributed by dispersing centers selected from the group consisting of chemically incorporated cationic or anionic groups present in from about 0 to 100 milliequivalents per 100 g of isocyanate prepolymer, chemically incorporated ethylene oxide units present in the isocyanate prepolymer in from about 0 to 30% by weight, based on the weight of the isocyanate prepolymer, and external emulsifiers present in about 0 to 30% by weight, based on the weight of the isocyanate prepolymers; and (c) an average molecular weight of from about 500 to 10,000 (ii) with an at least partially blocked hydrazone chain lengthening agent which forms hydrazine under the hydrophilic influence of water to form a mixture, and (B) mixing the mixture of (A), before significant increases in viscosity occur, with water to release the hydrazine and chain lengthen the prepolymer.
Claim 21
Dependent Claim
174 words
A process for the preparation of aqueous solutions or dispersions comprising: (A) mixing in the absence of water (i) a hydrophilic isocyanate prepolymer having (a) an average isocyanate functionality of from about 1.8 to 2.2; (b) its hydrophilic properties contributed by dispersing centers selected from the group consisting of chemically incorporated cationic or anionic groups present in from about 0 to 100 milliequivalents per 100 g of isocyanate prepolymer, chemically incorporated ethylene oxide units present in the isocyanate prepolymer in from about 0 to 30% by weight, based on the weight of the isocyanate prepolymer, and external emulsifiers present in about 0 to 30% by weight, based on the weight of the isocyanate prepolymers; and (c) an average molecular weight of from about 500 to 10,000 (ii) with an at least partially blocked hydrazone chain lengthening agent which forms hydrazine under the hydrophilic influence of water to form a mixture, and (B) mixing the mixture of (A), before significant increases in viscosity occur, with water to release the hydrazine and chain lengthen the prepolymer.
Claim 22
Dependent Claim
72 words
The process of claim 7 or 17 wherein the hydrophilic properties of the prepolymer are contributed by dispersing centers selected from the group consisting of chemically incorporated cationic or anionic groups present in from about 0.1 to 100 milliequivalents per 100 g of isocyanate prepolymer and chemically incorporated ethylene oxide units present in the isocyanate prepolymer in from about 0.5 to 30% by weight, based on the weight of the isocyanate prepolymer.
References Cited (Backward Citations)
US3420800A
Cited
US4066591A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-25 | 1984-11-24 | 1985-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-25 | 1988-11-24 | 1989-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-25 | 1992-11-24 | 1993-05-26 | $7700.00 | Window Closed / Lapsed |