US 4,948,859 AGranted

Extruder polymerization of polyurethanes

AssigneeMinnesota Mining and Manufacturing Company

InventorsJimmie L. Echols, Walton J. Hammar, Thomas A. Kotnour

Life of this patent

Estimating the term…

Loading patent…

Abstract

Bulk polymerization process for making radiation curable polyurethanes which comprises: (A) providing the following raw materials: (1) diisocyanate; (2) oligomeric diol>400 molecular weight; and (3) >1 chain extending monomer; (B) reacting the raw materials in a twin screw extruder under the following conditions: (1) molar ratio of isocyanate to hydroxy moieties of about 1; (2) ratio of chain extending monomer to other monomers sufficient to yield a polymer having chain extender incorporated at 0.1 to 10 weight percent; (3) extruder temperature sufficient to initiate and maintain reaction; and (4) residence time sufficient to obtain substantially complete reaction of diisocyanate; (C) cooling product polymer. Polyurethane product has weight average molecular weight greater than 80,000 and acrylate or methacrylate functionality. Process permits continuous production of radiation curable polyurethanes having narrow molecular weight distribution and high tensile strength.

Claims12

Dependent claims

A process for bulk polymerization of polyurethanes which comprises:

(A) providing the following raw materials:
(1) at least one diisocyanate;
(2) at least one oligomeric diol having a molecular weight of at least 400;
and
(3) at least one chain extending monomer having an acrylate or methacrylate moiety;
(B) continuously conveying the above raw materials to a twin screw extruder and reacting them together to the desired degree of conversion in the extruder while conveying the reacting mass through the extruder under the following conditions:
(1), molar ratio of isocyanate to hydroxy moieties 1.00.+-.0.05;
(2) ratio of chain extending monomer to other monomers sufficient to yield a polymer product having such chain extender incorporated therein to a level of from 0.1 to less than about 10 weight percent;
(3) extruder barrel temperature sufficient to initiate and maintain reaction between the raw materials;
and a residence time
(4) extruder configured to have sufficient to obtain substantially complete reaction of the diisocyanate as measured by infrared spectrometry of the extrudate;
and
(C) cooling the resulting product polymer from the discharge of the extruder;
to yield a polyurethane having the following properties:
(i) weight average molecular weight greater than 80,000;
and
(ii) acrylate or methacrylate functionality in the polymer molecule resulting from the chain extending monomer and which functionality survived the extruder reaction conditions.

14 more elements

A process for bulk polymerization of polyurethane which comprises:

(A) providing the following raw materials:
(1) at least one diisocyanate;
(2) at least one oligomeric diol having a molecular weight of at least 400;
and
(3) at least one chain extending monomer having an acrylate or methacrylate
moiety and selected from the group consisting of monomers having the formulas:
##STR7## wherein m=0-4
n.sub.1 =1-4
R1 is --H or --CH.sub.3
R.sub.7 is --H, --CH.sub.3, or --C.sub.2 H.sub.5
A is ##STR8## Y is ##STR9## (B) continuously conveying the above raw materials to a twin screw extruder and reacting them together to a desired degree of conversion in the extruder while conveying the reacting mass through the extruder under the following conditions:
(1) molar ratio of isocyanate to hydroxy moieties 1.00.+-.0.05;
(2) ratio of chain extending monomer to other monomers sufficient to yield a polymer product having such chain extender incorporated therein to a level of from 0.5 to less than about 10 weight percent;
(3) extruder barre 1 temperature sufficient to initiate and maintain reaction between the raw materials;
and
(4) extruder configured to have a residence time sufficient to obtain substantially complete reaction of the diisocyanate as measured by infrared spectrometry of the extrudate;
and
(C) cooling the resulting product polymer from the discharge of the extruder;
to yield a polyurethane having the following properties:
(i) weight average molecular weight greater than 80,000;
and
(ii) acrylate or methacrylate functionality in the polymer molecule resulting from the chain extending monomer and which functionality survived the extruder reaction conditions.

19 more elements

Dependencies are inferred from the claim text.