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US5136017A
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Continuous lactide polymerization
Assignee: Nova Chemicals International SA
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Filing: 1991-02-22
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Granted: 1992-08-04
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Expires: 2011-02-22
Abstract
Abstract Lactide monomers and copolymers may be polymerized by a continuous process using one or more continuous stirred tank reactors. The process offers productivity and product quality advantages over the batch process of polymerization.
Inventors
- 👤 Gregory B. Kharas
- 👤 Israel D. Fridman
- 👤 Speros P. Nemphos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:45
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/24; B01J19/245; C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00074; B01J2219/00087; B01J2219/00094; B01J2219/00132; B01J2219/00159
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
138 words
A continuous process for the polymerization of monomeric mixture comprising from 100 to 60 weight % of one or more monomers the formula ##STR2## wherein R 1 is hydrogen atom or a C 1-4 alkyl radical; and R 2 is a hydrogen atom or a C 1-8 alkyl radical, provided that R 1 and R 2 cannot both be a hydrogen atom; and 0-40 weight % of one or more copolymerizable monomers which comprises: (a) forming a melt or solution of said monomers; (b) passing said monomeric melt or solution continuously through a chain of at last two reactors operated at temperatures from 175° to 250° C. and at a pressure ranging from 0.5 to 5 atmospheres at a rate and for a residence time to provide not less than 75% conversion of said monomer mixture to polymer.
Claim 2
Dependent Claim
138 words
A continuous process for the polymerization of monomeric mixture comprising from 100 to 60 weight % of one or more monomers the formula ##STR2## wherein R 1 is hydrogen atom or a C 1-4 alkyl radical; and R 2 is a hydrogen atom or a C 1-8 alkyl radical, provided that R 1 and R 2 cannot both be a hydrogen atom; and 0-40 weight % of one or more copolymerizable monomers which comprises: (a) forming a melt or solution of said monomers; (b) passing said monomeric melt or solution continuously through a chain of at last two reactors operated at temperatures from 175° to 250° C. and at a pressure ranging from 0.5 to 5 atmospheres at a rate and for a residence time to provide not less than 75% conversion of said monomer mixture to polymer.
Claim 3
Dependent Claim
21 words
A process according to claim 1, wherein said copolymerizable monomer is selected from the group consisting of C 2-4 alkylene oxides.
Claim 4
Dependent Claim
41 words
A process according to claim 1, further comprising passing said melt of polymer through a preheater operated at a temperature from 180° to 220° C. at a pressure from 0.1 to 1.5 atmospheres for a time from 0.5 to 5 minutes.
Claim 5
Dependent Claim
39 words
A process according to claim 3, further comprising substantially upon exit from said preheater passing said polymer melt through a devolatilizer operated at a temperature from 150° to 225° C. and at a pressure of less than 0.02 atmospheres.
Claim 6
Dependent Claim
25 words
A process according to claim 1 wherein each successive reactor is operated at a temperature of up to 15° C. higher than the preceding reactor.
Claim 7
Dependent Claim
25 words
A process according to claim 4, wherein each successive reactor is operated at a temperature from 5° to 10° C. higher than the preceding reactor.
Claim 8
Dependent Claim
14 words
A process according to claim 5, wherein said reactors are continuous stirred tank reactors.
Claim 9
Dependent Claim
14 words
A process according to claim 6, wherein said devolatilizer is a falling strand devolatilizer.
Claim 10
Dependent Claim
20 words
A process according to claim 6, wherein the volatiles recovered from said falling strand devolatilizer is recycled to said reactors.
Claim 11
Dependent Claim
17 words
A process according to claim 8, further comprising adding to one or more said reactor(s) a catalyst.
Claim 12
Dependent Claim
23 words
A process according to claim 9, wherein said catalyst is selected from the group consisting of tin esters of C 1-18 carboxylic acids.
Claim 13
Dependent Claim
53 words
A process according to claim 10, wherein the diluent or solvent for said catalyst is selected from the group consisting of C 6-12 aromatic solvents, C 6-12 alkanes which are unsubstituted or substituted by a C 1-4 alkyl radical which are unsubstituted or substituted by a C 1-4 alkyl radical, C 1-6 ketones.
Claim 14
Dependent Claim
12 words
A process according to claim 11, wherein said catalyst is stannous octoate.
References Cited (Backward Citations)
US3879352A
Cited
US4643734A
Cited
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