Multilayered clear over color polyolefin sheets and layered backing structure
AssigneeA. Schulman, Inc.
InventorDennis C. Smith
Life of this patent
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Abstract
A multilayer structure includes a clear polyolefin layer, a colored polyolefin layer, and a random polyolefin backing layer. The colored and backing layers are coextruded and are permanently bonded at a layer interface, which is exclusive of an adhesive. The structure has a DOI of 70 or greater and passes a gravelometer impact test per the GM9508P standard, with a 10 pint load, at a −30° C. temperature, and at an impact angle of 30 degrees. Among other uses, the structures are appropriate for use as body panels in the motor vehicle industry. The structures display a “class A” finish and meet a variety of requirements for durability and weatherability. An ABA structured backing layer and a method of making it are also described herein.
Claims31
An extruded polymeric composition comprising:
- 60 to 99% by weight of the composition of a clear isotactic polypropylene/ethylene copolymer, wherein the copolymer has 70% or greater isotacticity, 0.5-12% ethylene content, a crystallinity greater than 60%, and a Rockwell hardness of R80 or greater;
- and
- a clarifier present in an amount up to 3% by weight of the composition;
- wherein the composition is adapted to be extruded into a sheet that prior to addition of any of pigment or special effects material has a haze of 10% or less.
A clear, colored, or translucent extruded polymeric sheet layer comprising:
- an isotactic polypropylene/ethylene copolymer, wherein the copolymer has 70% or greater isotacticity, 0.5-12% ethylene content, a crystallinity greater than 60%, a Rockwell hardness of R80 or greater;
- wherein the polymeric sheet layer has a Class A finish.
A method for making a polymeric sheet, the method comprising:
- making an additive concentrate by steps including:
- feeding a UV stabilizer, slip agent, or both together with a carrier resin to a first extruder;
- and
- extruding the additive concentrate;
- and making a polymeric sheet layer by steps including:
- feeding a polyolefin and the additive concentrate to a second extruder;
- and
- extruding the polymeric sheet layer;
- wherein the polymeric sheet layer comprises a layer including 60 to 99% by weight of the sheet layer of a clear isotactic polypropylene/ethylene copolymer, wherein the copolymer has 70% or greater isotacticity, 0.5-12% ethylene content, a crystallinity greater than 60%, and a Rockwell hardness of R80 or greater;
- and
- a clarifier present in an amount up to 3% by weight of the sheet layer;
- wherein the composition is adapted to be extruded to create a sheet layer that prior to addition any of pigment or special effects material has a haze of 10% or less.
A multilayer polymeric structure comprising:
- a clear, colored, or translucent top polymeric layer that includes an isotactic polypropylene/ethylene copolymer, wherein the copolymer has 70% or greater isotacticity, 0.5-12% ethylene content, a crystallinity greater than 60%, a Rockwell hardness of R80 or greater;
- and
- a polyolefinic backing layer;
- wherein the multilayer polymeric structure is sheet coextruded and is exclusive of a tie layer;
- wherein the polymeric sheet has a DOI of 70 or greater and passes a gravelometer impact test per the GM9508P standard, with a 10 pt load, at a −30° C. temperature, and at an angle of 30 degrees.
Dependencies are inferred from the claim text.