Low shrink low density laminate formulation

• US 7,341,785 B2
• Filed: 06/20/2003
• Issued: 03/11/2008
• Est. Priority Date: 08/01/2002
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Mitchell, Harry A, Kia, Hamid G, Buffa, Mark A, Wathen, Terrence J
• Primary Examiner(s): EDWARDS, NEWTON O
• Application Number:
  US10/601,250
• Publication Number:
  US 20040023012A1
• Time in Patent Office: 1,726 Days
• Field of Search: 264/255, 264/250, 428/31, 428/137, 428/403, 428/172, 428/402, 428/340, 428/354, 428/364, 428/189, 428/193, 428/212, 428/213, 428/219, 428/220, 428/323, 428/325, 428/423.7, 428/482, 524/494
• US Class Current: 428/423.7
• CPC Class Codes: B29C 70/003 characterised by the matrix material, e.g. material composition or physical properties
• CPC Class Codes: B29C 70/025 with particular filler
• CPC Class Codes: B29C 70/30 Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
• CPC Class Codes: B29C 70/305 Spray-up of reinforcing fibres with or without matrix to form a non-coherent mat in or on a mould B29C41/365, B29C70/32, B29C70/34, B29C70/502, B29C70/508 take precedence; coating a former by spraying plastics B29C41/08
• CPC Class Codes: B32B 17/04 bonded with or embedded in a plastic substance
• CPC Class Codes: B32B 27/00 Layered products comprising a layer of synthetic resin fibrous or filamentary layer made of a synthetic resin B32B5/02; particulate layer made of a synthetic resin B32B5/16; foamed layer made of a synthetic resin B32B5/18
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/31565 Next to polyester [polyethylene terephthalate, etc.]
• CPC Class Codes: Y10T 428/31794 Of cross-linked polyester
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers

Abstract

Composite articles are prepared by a spray up operation. In a first step, a gel coat is applied onto a mold surface which has been optionally pretreated with a mold release coating. Next, a barrier coat is applied over the gel coat in the mold and thereafter a laminate formula is applied over the barrier coat. The laminate contains from 40-80% by weight paste and from 20-60% by weight reinforcing fibers. In a preferred embodiment, the paste comprises 90% or more by weight resin, up to 5% filler, and an initiator composition capable of initiating cure at a temperature of 50° C. or lower. In a preferred embodiment, the multilayer composite has a thickness of about 15 mm or less, and is useful as an automobile body panel. The laminate preferably comprises a low shrink, low density glass fiber filled polyester resin. In a preferred embodiment, the paste of the laminate contains a dicyclopentadiene unsaturated polyester resin, polymeric hollow microspheres, and an initiator capable of initiating curing at room temperature or at temperature of 50° C. or less.

Claims

1. A laminate composition comprising a paste and filler, wherein the paste comprises,

a dicyclopentadiene unsaturated polyester resin;

polymeric hollow microspheres; and

an initiator composition capable of initiating curing at a temperature of 50°

C. or less, and wherein the filler comprises reinforcing fibers having a length greater than or equal about 6 mm.

2. A composition according to claim 1, wherein the reinforcing fibers comprise glass fibers having a length greater than or equal about 12 mm.

3. A composition according to claim 1, wherein the reinforcing fibers comprise glass fibers of weight approximately 25 mm.

4. A composition according to claim 1, wherein the paste comprises 90% or more by weight resin and up to 5% by weight polymeric hollow microspheres.

5. A composition according to claim 1, wherein the microspheres are coated with calcium carbonate.

6. A composition according to claim 1, wherein the density of the laminate layer after cure is 1.2 g/cm³ or less.