Process to Improve the Adhesion Between Thermosetting Laminate and Thermoplastic Shell
The present invention related to a process to improve the adhesion between a thermosetting laminate and a thermoplastic shell in making reinforced plastic laminates for sanitary fixtures, such as shower receptors, spas, bathtubs, sinks, lavatories and the like, and composites laminates for transportation, marine, and construction applications. The adhesion improvement is through a designed post-curing process of the cured composites laminates. The thermosetting resin used in the construction of composites laminate can be unsaturated polyester resin of any kind, vinyl ester resin, or combination of both.
1 . A reinforced plastic laminate made by the process of:
forming a thermosetting composite laminate by applying a thermosetting unsaturated polyester resin onto a surface of a thermoplastic sheet or an intermediate interposed between the thermosetting resin and the surface of the thermoplastic sheet;
allowing the thermosetting resin to gel and optionally reach a peak exotherm; and
post-curing by heating the thermosetting composite laminate at a temperature of about 90° F. to about 210° F. to form the reinforced plastic laminate.
2 . An article comprising the reinforced plastic laminate of claim 1 .
3 . The plastic laminate of claim 1 , wherein the process further comprises shaping the thermoplastic sheet to form a thermoplastic shell, and applying the thermosetting rein onto the surface of the thermoplastic shell or intermediate interposed between the thermosetting resin and the surface of the thermoplastic shell.
4 . The plastic laminate of claim 3 , wherein shaping the thermoplastic sheet comprises a thermoforming process.
5 . The plastic laminate of claim 1 , wherein the process further comprises cooling the heated thermosetting composite laminate to ambient temperature.
6 . The plastic laminate of claim 1 , wherein the thermoplastic sheet comprises a thermoplastic resin selected from the group consisting of acrylics, acrylonitrile-butadiene-styrene (ABS), acrylonitrile-styrene-acrylate (ASA), modified acrylics, modified ABS, and modified ASA.
7 . The plastic laminate of claim 6 , wherein the thermoplastic sheet comprises a combination of the thermoplastic resins in a co-extruded sheet.
8 . The plastic laminate of claim 1 , wherein the thermoplastic sheet comprises a thermoplastic resin that can be softened by monomers in the thermosetting resin.
9 . The plastic laminate of claim 1 , wherein the thermosetting resin comprises a vinyl ester resin.
10 . The plastic laminate of claim 1 , wherein the thermosetting resin comprises a high DCPD-type unsaturated polyester resin.
11 . The plastic laminate of claim 1 , wherein the thermosetting resin comprises a thermosetting resin system comprising an ethylenically unsaturated monomer in an amount of about 25 to about 55 weight percent, based on the total weight of the thermosetting resin system.
12 . The plastic laminate of claim 11 , wherein the thermosetting resin system is a filled system.
13 . The plastic laminate of claim 11 , wherein the thermosetting resin system is an unfilled system.
14 . The plastic laminate of claim 11 , where the thermosetting resin system comprises a low profile resin.
15 . The plastic laminate of claim 14 , wherein the low profile resin comprises polyvinyl acetate.
16 . The plastic laminate of claim 1 , wherein the thermosetting composite laminate is a fiber reinforced composite.
17 . The plastic laminate of claim 1 , wherein the thermosetting composite laminate comprises an insert or core material.
18 . The plastic laminate of claim 1 , wherein forming the thermosetting composite laminate is by an open molding process.
19 . The plastic laminate of claim 1 , wherein forming the thermosetting composite laminate is by a closed molding process.
20 . The plastic laminate of claim 1 , wherein the thermosetting resin of the thermosetting composite laminate has a thickness less than about ¼ inch.
21 . The plastic laminate of claim 1 , wherein post-curing the thermosetting composite laminate is at a temperature of about 110° F. to about 190° F.
22 . The plastic laminate of claim 1 , wherein post-curing the thermosetting composite laminate is conducted for about 5 minutes to about 12 hours.
23 . The plastic laminate of claim 1 , wherein post-curing the thermosetting composite laminate is conducted for about 10 minutes to about 6 hours.