Shaped polymeric articles

Claim 2

A process for the preparation of a shaped polymeric article which comprises reacting a mixture consisting essentially of of (i) from 1% to 60% by weight of the precursors of a cross-linked polymeric material consisting essentially of at least one polymer having a Tg of not more than 25°C, a molecular weight of at least 3,000 and which contains hydroxyl groups and at least one polyisocyanate cross-linking agent, and (ii) from 99% to 40% by weight of at least one vinyl monomer which is free of groups which react with said hydroxylcontaining polymer or said polyisocyanate, to produce an article of a cross-linked polymeric material having a Tg of not more than 25°C and a vinyl polymer, and shaping the mixture while it is still fluid, the precursors of the cross-linked polymeric material being soluble in or dispersed in the vinyl monomer, and in which the reaction of the polymer with the cross-linking agent is substantially completed before polymerization of the vinyl monomer is allowed to proceed to the extent that the vinyl polymer so produced forms a separate phase.

Claim 3

A process as claimed in claim 1, in which the mixture comprises 2% to 30% by weight of the precursors of the cross-linked polymeric material and from 98% to 70% by weight of a vinyl monomer.

Claim 4

A process as claimed in claim 1, in which the mixture comprises from 5% to 30% by weight of the precursors of the cross-linked polymeric material and from 95% to 70% by weight of a vinyl monomer.

Claim 5

A process as claimed in claim 1, in which the mixture comprises from 10% to 20% by weight of the precursors of the cross-linked polymeric material and from 90% to 80% by weight of a vinyl monomer.

Claim 6

A process as claimed in claim 1, in which the Tg of the polymer from which the cross-linked polymeric material is formed is not more than 0°C.

Claim 7

A process as claimed in claim 1, in which the polymer from which the cross-linked polymeric material is formed has a molecular weight of at least 5,000.

Claim 8

A process as claimed in claim 6, in which the polymer from which the cross-linked polymeric material is formed has a molecular weight of at least 20,000.

Claim 9

A process as claimed in claim 1, in which the polymer is a copolymer of an alkyl acrylate and a hydroxy ethyl acrylate or methacrylate.

Claim 10

A process as claimed in claim 8 in which the polymeric material is a copolymer of butyl acrylate and hydroxy ethyl methacrylate.

Claim 11

A process as claimed in claim 1, in which the polymeric material is a copolymer of ethylene, an alkyl acrylate or methacrylate, and a hydroxy alkyl acrylate or methacrylate.

Claim 12

A process as claimed in claim 10, in which the polymeric material is a copolymer of ethylene, methyl methacrylate or ethyl acrylate, and hydroxy ethyl methacrylate.

Claim 13

A process as claimed in claim 1, in which the polyisocyanate is 4:4'-diphenylmethane diisocyanate or hexamethylene diisocyanate.

Claim 14

A process as claimed in claim 1, in which the vinyl monomer is selected from the group consisting of methyl methacrylate, styrene, and a combination of methyl methacrylate and styrene or acrylonitrile.

Claim 15

A process for the preparation of a shaped polymeric article which comprises forming a mixture which consists essentially of (1) from 1% to 60% by weight of the precursors of a crosslinked polyurethane, said precursors consisting essentially of (a) at least one polymer having a Tg of not more than 25°C, a molecular weight of at least 3,000 and which contains hydroxyl groups, and (b) at least one polyisocyanate cross-linking agent, and (2) from 99% to 40% by weight of at least one vinyl monomer which is free of groups which react with said hydroxyl containing polymer or said polyisocyanate, said precursors being soluble or dispersed in said vinyl monomer, reacting said precursors in said mixture to form a crosslinked polyurethane having a Tg of not more than 25°C and polymerizing said vinyl monomer to form a vinyl polymer, the reaction of said hydroxyl containing polymer with the polyisocyanate cross-linking agent being substantially completed before polymerization of said vinyl monomer is allowed to proceed to the extent that the vinyl polymer so produced forms a separate stage, and shaping said mixture while it is still fluid.

Claim 16

A process for the preparation of a shaped polymeric article which comprises forming a mixture which consists essentially of (1) from 1% to 60% by weight of the precursors of a crosslinked polyurethane, said precursors consisting essentially of (a) at least one polymer having a Tg of not more than 25°C, a molecular weight of at least 3,000 and which contains hydroxyl groups, and (b) at least one polyisocyanate cross-linking agent, and (2) from 99% to 40% by weight of at least one vinyl monomer which is free of groups which react with said hydroxyl containing polymer or said polyisocyanate, said precursors being soluble or dispersed in said vinyl monomer, reacting said precursors in said mixture to form a crosslinked polyurethane having a Tg of not more than 25°C and polymerizing said vinyl monomer to form a vinyl polymer, the reaction of said hydroxyl containing polymer with the polyisocyanate cross-linking agent being substantially completed before polymerization of said vinyl monomer is allowed to proceed to the extent that the vinyl polymer so produced forms a separate stage, and shaping said mixture while it is still fluid.

Claim 17

A shaped polymeric article produced by the process of claim 14.

Claim 18

A process as set forth in claim 14 in which said precursors of a cross-linked polyurethane include catalysts for the reaction of said polymer with said polyisocyanate.

Claim 19

A process as set forth in claim 14 in which said mixture includes a catalyst for the polymerization of said vinyl monomer.

Claim 20

A process as set forth in claim 14 in which said mixture contains a fibrous reinforcing agent.