Process for the polymerization of formaldehyde
First Claim
1. A method for preparing a polyoxymethylene, comprising the step of supplying anhydrous monomeric formaldehyde to a reaction medium comprising an organic diluent which is a liquid and non-solvent for the polyoxymethylene under the reaction conditions and inert towards the other constituents of the reaction medium, and comprising from 0.001 to 0.5 percent by weight of a catalyst based upon the polyoxymethylene, dispersed in said medium, said catalyst having a molecular weight of from 1,000 to 50,000, containing block A in a proportion of from 1 to 89 weight percent, and consisting of a block copolymer carrying ionic couples on its macromolecular chain, said block copolymer being defined by the general structure A-B in which:
- A is a polylactonic block consisting of recurring units;
##EQU5## obtainable from at least one monomeric lactone of the general formula;
##EQU6## B is a polylactam block consisting of recurring units;
##EQU7## obtainable from at least one monomeric lactam of the general formula;
##EQU8## wherein PM1 and PM2 are polymethylene chains having from 2 to 13 and 3 to 13 carbon atoms, respctively, non-substituted or having at least one hydrogen atom replaced by a radical selected from the group consisting of alkyl, aryl, alkylaryl and cycloalkyl radicals.
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Abstract
Polyformaldehyde is prepared by feeding anhydrous formaldehyde to a reaction medium containing a liquid organic diluent non-solvent for the polyformaldehyde and non-reactive towards the other constituents of the reaction medium, and containing in a dispersed form a copolymer A-B, wherein
A is a polylactonic block of recurring units ##EQU1## B is a polylactamic block of recurring units ##EQU2## wherein PM1 and PM2 are linear polymethylene chains having from 2 to 13 and 3 to 13 carbon atoms, respectively.
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Citations
11 Claims
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1. A method for preparing a polyoxymethylene, comprising the step of supplying anhydrous monomeric formaldehyde to a reaction medium comprising an organic diluent which is a liquid and non-solvent for the polyoxymethylene under the reaction conditions and inert towards the other constituents of the reaction medium, and comprising from 0.001 to 0.5 percent by weight of a catalyst based upon the polyoxymethylene, dispersed in said medium, said catalyst having a molecular weight of from 1,000 to 50,000, containing block A in a proportion of from 1 to 89 weight percent, and consisting of a block copolymer carrying ionic couples on its macromolecular chain, said block copolymer being defined by the general structure A-B in which:
A is a polylactonic block consisting of recurring units;
##EQU5## obtainable from at least one monomeric lactone of the general formula;
##EQU6## B is a polylactam block consisting of recurring units;
##EQU7## obtainable from at least one monomeric lactam of the general formula;
##EQU8## wherein PM1 and PM2 are polymethylene chains having from 2 to 13 and 3 to 13 carbon atoms, respctively, non-substituted or having at least one hydrogen atom replaced by a radical selected from the group consisting of alkyl, aryl, alkylaryl and cycloalkyl radicals.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
Specification