US4115373A
Expired / Lapsed
US
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Process for the production of polyisocyanates containing isocyanurate groups
Assignee: Bayer AG
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Filing: 1976-11-01
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Granted: 1978-09-19
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Expires: 1996-11-01
Abstract
Abstract This invention relates to a new process for the production, in inert organic solvents, of physiologically compatible polyisocyanates containing isocyanurate groups which have a monomeric diisocyanate content, based on solids, of at most 0.7%, by weight. The process uses Mannich bases as the trimerizing catalyst at temperatures below 60° C and the reaction is terminated at the desired degree of trimerization by thermally decomposing the catalyst or by deactivating with a catalyst poison.
Inventors
- 👤 Gerhard Henes
- 👤 Hans Jurgen Muller
- 👤 Pramod Gupta
- 👤 Joachim Zirner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:14
CPC Classifications
C; C07; C07D; C07D251/00; C07D251/02; C07D251/12; C07D251/26; C07D251/30; C07D251/34; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/77; C08G18/78; C08G18/79; C08G18/791
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
105 words
A process for the production of polyisocyanates containing isocyanurate groups and having a monomeric diisocyanate content, based on solids, of at most 0.7%, by weight, comprising (1) partially trimerizing the isocyanate groups in organic diisocyanates in the presence of catalysts which accelerate the trimerizing reaction of isocyanate groups and (2) terminating the trimerizing reaction at the desired degree of trimerization by thermally decomposing the catalyst used or by deactivating the catalyst used by adding a catalyst poison, wherein (a) Mannich bases are used as catalysts and (b) the trimerizing reaction is carried out in the presence of inert solvents at a temperature below 60° C.
Claim 2
Dependent Claim
105 words
A process for the production of polyisocyanates containing isocyanurate groups and having a monomeric diisocyanate content, based on solids, of at most 0.7%, by weight, comprising (1) partially trimerizing the isocyanate groups in organic diisocyanates in the presence of catalysts which accelerate the trimerizing reaction of isocyanate groups and (2) terminating the trimerizing reaction at the desired degree of trimerization by thermally decomposing the catalyst used or by deactivating the catalyst used by adding a catalyst poison, wherein (a) Mannich bases are used as catalysts and (b) the trimerizing reaction is carried out in the presence of inert solvents at a temperature below 60° C.
Claim 3
Dependent Claim
14 words
The process of claim 1, wherein 2,4-diisocyanato toluene is used as the organic diisocyanate.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein said solvent is an ester.
Claim 5
Dependent Claim
28 words
The process of claim 3 wherein the solvent is selected from the group consisting of butyl acetate, ethyl acetate, ethyl glycol acetate, dibutyl phthalate, and diphenyl octyl phthalate.
Claim 6
Dependent Claim
39 words
The process of claim 1 wherein said Mannich base is prepared from (A) a monohydric or polyhydric phenol containing at least one CH-bond condensable with respect to formaldehyde in the o- and/or p-position, (B) formaldehyde and (C) dimethyl amine.
Claim 7
Dependent Claim
15 words
The process of claim 1 wherein said catalyst poison is an alkylating or acylating agent.
Claim 8
Dependent Claim
25 words
The process of claim 1 wherein the Mannich base is used in a concentration of from 200 to 2,500 ppm based on the starting polyisocyanate.
Claim 9
Dependent Claim
27 words
The process of claim 1 wherein the reaction is stopped after from 60 to 70% of the isocyanate groups present in the starting isocyanate have been trimerized.
Claim 10
Dependent Claim
8 words
The product of the process of claim 1.
Claim 11
Dependent Claim
26 words
A process for the production of polyurethane plastics by reacting the polyisocyanates of claim 1 with compounds containing isocyanate-reactive hydrogen atoms by the isocyanate polyaddition process.
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) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |