US4894428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for coating substrates with polyurethane ureas
Assignee: Bayer AG
•
Filing: 1989-01-03
•
Granted: 1990-01-16
•
Expires: 2009-01-03
Abstract
Abstract The present invention is directed to a process for coating substrates with polyurethane ureas which is characterized in that a substrate is coated with a product, which has been obtained by the reation of (A) a prepolymer based on an aromatic polyisocyanate containing on average two ketoxime-blocked NCO groups and having an average molecular weight of about 500 to 15,000 with (B) a chain-extending agent corresponding to the formula H.sub.2 N--R'--NH.sub.2 in which R' is an aliphatic or cycloaliphatic radical, in the presence of solvents at temperatures above 50° C. and at an equivalent ratio of blocked NCO groups to NH 2 groups of 1.43 to 1.02, wherein after about 40 to 90% of the available amino groups have reacted, the reaction is completed with crosslinking at temperatures above 120° C. The present invention is also directed to the coated substrates produced by this process.
Inventors
- 👤 Wilhelm Thoma
- 👤 Josef Pedain
- 👤 Waldemar Kling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:09
CPC Classifications
D; D06; D06N; D06N3/00; D06N3/12; D06N3/14; C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; C08G18/12; C08G18/28; C08G18/40; C08G18/4009; C08G18/4018; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31551; Y10T428/31591; Y10T442/00; Y10T442/20; Y10T442/2549; Y10T442/2566
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
122 words
A process for coating a substrate with a polyurethane urea which comprises reacting a prepolymer based on an aromatic polyisocyanate containing an average of two ketoxime blocked NCO groups and having an average molecular weight of about 500 to 15,000 with (B) a chain-extending agent corresponding to the formula H.sub.2 N--R'--NH.sub.2 in which R' is an aliphatic or cycloaliphatic radical, in the presence of a solvent at a temperature of greater than 50° C. and at an equivalent ratio of blocked isocyanate groups to NH 2 groups of 1.43 to 1.02 until about 40 to 90% of the amino groups have reacted, applying the partially reacted prepolymer to a substrate and crosslinking the coating at a temperature of greater than 120° C.
Claim 2
Dependent Claim
122 words
A process for coating a substrate with a polyurethane urea which comprises reacting a prepolymer based on an aromatic polyisocyanate containing an average of two ketoxime blocked NCO groups and having an average molecular weight of about 500 to 15,000 with (B) a chain-extending agent corresponding to the formula H.sub.2 N--R'--NH.sub.2 in which R' is an aliphatic or cycloaliphatic radical, in the presence of a solvent at a temperature of greater than 50° C. and at an equivalent ratio of blocked isocyanate groups to NH 2 groups of 1.43 to 1.02 until about 40 to 90% of the amino groups have reacted, applying the partially reacted prepolymer to a substrate and crosslinking the coating at a temperature of greater than 120° C.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein the equivalent ratio of blocked NCO groups to amino groups is 1.18:1 to 1.05:1.
Claim 4
Dependent Claim
24 words
The process of claim 1 which comprises reacting about 50 to 70% of the amino groups prior to applying the coating to a substrate.
Claim 5
Dependent Claim
27 words
The process of claim 1 wherein said chain-extending agent corresponds to the formula ##STR2## wherein R and R 1 represent H or C 1 -C 4 alkyl.
Claim 6
Dependent Claim
27 words
The process of claim 1 wherein the initial reaction of component (A) and (B) is carried out at a temperature of about 70° to about 100° C.
Claim 7
Dependent Claim
20 words
The process of claim 1 which comprises conducting said crosslinking reaction at a temperature of about 150° to 160° C.
Claim 8
Dependent Claim
20 words
The process of claim 1 wherein said prepolymer is also based on a polyhydroxypolyether, a polyhydroxypolyester or a mixture thereof.
Claim 9
Dependent Claim
29 words
The process of claim 7 wherein said prepolymer is based on a mixture comprising about 40 to 90% by weight of a polyhydroxypolyether and the remainder comprising a polyhydroxypolyester.
Claim 10
Dependent Claim
12 words
A coated substrate produced in accordance with the process of claim 1.
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) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |