Process for producing a synthetic resin article having improved resistance to surface abrasion

Claim 1

In a process for producing a synthetic resin article having a synthetic resin surface layer firmly adhered to a resin and having greatly improved resistance to surface abrasion; said process comprising the steps of: a. spreading onto all or part of the inner surface of a mold member a polymerizable material selected from the group consisting of (i) a compound having a total of at least three acryloxy (CH 2 ═CH.sup.. CO.sup.. O--) and/or methacryloxy (CH 2 ═C(CH 3 ).sup.. CO.sup.. O--) groups in the molecule, (ii) a monomer mixture comprising at least 40% by weight of said compound and at most 60% by weight of other copolymerizable ethylenically unsaturated monomer and (iii) a partially polymerized product of said compound or of said monomer mixture, b. adhering a preformed film having little or no affinity for said polymerizable material closely to the spread surface, c. polymerizing said polymerizable material to an extent such that the polymerized material can not be swollen with or dissolved into a monomer for the base resin to be charged into said mold member, d. removing the film from the polymerized material, e. charging a mixture of the monomer for the base resin and a polymerization initiator into the mold, f. polymerizing the monomer, and g. after the completion of polymerization, releasing the cast article from the mold, the improvement comprising upstream of a polymerization zone wherein said polymerizable material is polymerized while passing therethrough, coating said polymerizable material onto the surface of at least one of two horizontal upper and lower endless belts continuously traveling at the same speed and in the same direction and applying a continuous length of said film onto the polymerizable material on the continuously traveling endless belts whereby said length of film is closely adhered onto the coated polymerizable material; downstream of the polymerization zone, continuously removing said length of film from the polymerized material on said endless belts; and continuously charging said monomer mixture for the base resin into an upstream end of a casting space defined by the two opposed,, horizontal upper and lower polymerized material-coated belt surfaces and side seals.