Claims
- 1. A method for preparing a plastic composite comprising capstock overlying and integrally bonded to an underlying structural ply, wherein said composite is formed by feedblock coextrusion of a molten capstock composition and a molten structural ply composition, the improvement comprising:
- forming by feedblock coextrusion the composite from the capstock composition comprising
- (A) about 40 to about 88 wt. % of a thermoplastic resin having a molecular weight of at least about 125,000 daltons, and selected from the group consisting of methyl methacrylate resin and a copolymer of methyl methacrylate and a C.sub.1 to C.sub.4 alkyl acrylate, and
- (B) about 12 to about 60 wt. % of an acrylate-based impact-modifier resin in the form of discrete multi-layer polymeric particles, wherein the composition has a melt flow index of from about 0.4 to about 0.75, as measured by ASTM Method D-1238, Condition I, and wherein the discrete multi-layered polymeric particles are dispersed in the thermoplastic resin which constitutes a continuous phase of the composition;
- and from a structural ply composition having substantially the same melt flow index as that of the capstock composition.
- 2. The method of claim 1 wherein the thermoplastic resin consists essentially of a copolymer of about 0.1 to about 12 wt. % of alkyl acrylate and about 88 to about 99.9 wt. % of methyl methacrylate.
- 3. The method of claim 2 including about 0.1 to about 4 wt. % of alkyl acrylate and about 96 to about 99.9 wt. % of methyl methacrylate.
- 4. The method of claim 2 wherein the molecular weight is no greater than about 220,000 daltons and the melt flow index is about 0.45 to about 0.6.
- 5. The method of claim 2 wherein the impact-modifier resin comprises multi-layered polymeric particles having an intermediate layer sandwiched between a core layer and an outer layer, the core layer being a non-elastomeric polymer, the intermediate layer being an elastomeric polymer, and the outer layer being a hard polymer.
- 6. The method of claim 5 wherein each of the core and outer layers comprises random copolymers of methyl methacrylate and ethyl acrylate and the intermediate layer comprises a random copolymer of butyl acrylate and styrene.
- 7. The method of claim 2 wherein a source of the impact-modifier resin is an admixture which includes a drying aid resin comprising a random copolymer of about 90 to about 99.9 methyl methacrylate and about 0.1 to about 10 wt. % of an alkyl acrylate having a molecular weight of about 95,000 to about 200,000 daltons.
- 8. The method of claim 1 wherein the structural ply composition is selected from ABS, polycarbonate, polycarbonate-ABS blends, or PVC.
- 9. The method of claim 1 wherein the capstock composition overlies a mutually compatible polymer interlayer integrally bonded to the underlying structural ply.
- 10. The method of claim 9 wherein the mutually compatible polymer interlayer is ABS and the underlying structural ply is high impact polystyrene.
- 11. The method of claim 9 wherein the mutually compatible polymer interlayer is a propylene polymer grated with methyl methacrylate and the underlying structural ply is polypropylene.
Parent Case Info
This is a continuation of U.S. patent application Ser. No. 07/669,249, filed Mar. 14, 1991, now abandoned, which is a continuation-in-part of U.S. patent application Ser. No. 532,044, filed May 25, 1990, now abandoned.
US Referenced Citations (20)
Foreign Referenced Citations (2)
Number |
Date |
Country |
210450 |
Jun 1986 |
EPX |
63-254114 |
Oct 1988 |
JPX |
Non-Patent Literature Citations (3)
Entry |
Nissel, F. R., "Sheet Co-Extrusion After 15 Years-1981 Status Report", pp. 14-19, in Advances in Plastics Technology, Oct., 1981. |
Rohm and Haas Company's Technical Literature, "Coextruded Plexiglas (TM) DR (TM)/ABS Composites", dated approximately 1977. |
"Coextruded Plexiglas DR/ABS/Composites"; 1977. |
Continuations (1)
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Number |
Date |
Country |
Parent |
669249 |
Mar 1991 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
532044 |
May 1990 |
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