Structural composite laminates

• US 9,096,039 B2
• Filed: 03/04/2011
• Issued: 08/04/2015
• Est. Priority Date: 03/04/2010
• Status: Active Grant

• Current Assignee: Zephyros, Inc.
• Original Assignee: Zephyros, Inc.
• Inventors: Chmielewski, Craig, Madaus, Brandon
• Primary Examiner(s): TOLIN, MICHAEL A
• Application Number:
  US13/040,704
• Publication Number:
  US 20120028032A1
• Time in Patent Office: 1,614 Days
• Field of Search: 156/79, 156/244.11
• US Class Current: 1/1
• CPC Class Codes: B29C 44/128 Internally reinforcing constructional elements, e.g. beams
• CPC Class Codes: B29C 44/18 Filling preformed cavities B29C44/1204 takes precedence
• CPC Class Codes: B32B 15/04 comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a bituminous or tarry layer B32B11/08; next to a water-setting substance layer B32B13/06; next to a glass layer B32B17/061; next to a cellulosic plastic layer B32B23/042
• CPC Class Codes: B32B 15/046 of foam
• CPC Class Codes: B32B 15/092 comprising epoxy resins
• CPC Class Codes: B32B 2266/0228 Aromatic vinyl resin, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 2266/0242 Acrylic resin
• CPC Class Codes: B32B 2266/025 Polyolefin vinyl or acrylic copolymers B32B2266/0221, B32B2266/0242
• CPC Class Codes: B32B 2266/0264 Polyester
• CPC Class Codes: B32B 2266/0271 Epoxy resin
• CPC Class Codes: B32B 2266/0278 Polyurethane
• CPC Class Codes: B32B 2270/00 Resin or rubber layer containing a blend of at least two different polymers
• CPC Class Codes: B32B 2307/50 having particular mechanical properties
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/542 Shear strength
• CPC Class Codes: B32B 27/065 of foam
• CPC Class Codes: B32B 27/16 specially treated, e.g. irradiated
• CPC Class Codes: B32B 27/281 comprising polyimides
• CPC Class Codes: B32B 27/285 comprising polyethers
• CPC Class Codes: B32B 27/286 comprising polysulphones; polysulfides
• CPC Class Codes: B32B 27/30 : comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/304 : comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/306 : comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: B32B 27/308 : comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/34 : comprising polyamides
• CPC Class Codes: B32B 27/36 : comprising polyesters
• CPC Class Codes: B32B 27/365 : comprising polycarbonates
• CPC Class Codes: B32B 27/38 : comprising epoxy resins
• CPC Class Codes: B32B 27/42 : comprising condensation resins of aldehydes, e.g. with phenols, ureas or melamines
• CPC Class Codes: B32B 5/18 : characterised by features of a layer of foamed material
• CPC Class Codes: B32B 5/20 : foamed in situ
• CPC Class Codes: B32B 7/10 : at least one layer having inter-reactive properties
• CPC Class Codes: Y10T 428/249953 : Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249987 : With nonvoid component of specified composition
• CPC Class Codes: Y10T 428/249991 : Synthetic resin or natural rubbers

Abstract

A composite laminate is formed from a structural foam and a reinforcement layer. The matched surface tensions of the structural foam and reinforcement layer result in increased bond strength between the structural foam and the reinforcement layer, thus providing for improved physical characteristics including improved lap shear and flexural strength.

Claims

1. A method of forming a composite laminate for providing sealing, baffling or reinforcement to a structure, the method comprising:

providing a reinforcement layer having a high surface tension of at least about 35 dynes/cm;

locating an epoxy-based expandable structural foam material onto the reinforcement layer to form the composite laminate wherein the surface tensions of the structural foam and reinforcement layer are within about 15 dynes/cm of one another;

exposing the composite laminate to a temperature greater than 150°

C. prior to any activation of the expandable structural foam so that a covalent bond is formed between the reinforcement layer and structural foam;

wherein the high surface tensions of the reinforcement layer and structural foam provide sufficient wetting for load transfer from the structural foam to the reinforcement layer to;

i. increase the tensile modulus of the composite laminate relative to the structural foam without the reinforcement layer where the difference between the tensile modulus of the composite laminate and the tensile modulus of the structural foam without the reinforcement layer is a range from 154 MPa to 633 MPa post-activation; and

ii. increase the lap shear strength of the composite laminate relative to the structural foam without the reinforcement layer where the difference between the lap shear strength of the composite laminate and the lap shear strength of the structural foam without the reinforcement layer is a range from 0.68 MPa to 1.35 MPa post-activation.

3. The method of claim 1, wherein the reinforcement layer comprises a polymeric film of polyethylene terephthalate.

5. The method of claim 1, wherein the structural foam is located onto the reinforcement layer by a co-extrusion process.

6. The method of claim 5, wherein the covalent bond between the reinforcement layer and the structural foam is not formed during the co-extrusion process.

2. The method of claim wherein the reinforcement layer includes a carboxylic acid chemical functional group and the structural foam material includes a component that forms a covalent bond with the carboxylic acid of the reinforcement layer upon exposure to temperatures greater than 150°

C.

4. The method of claim 2, wherein the structural foam comprises an epoxy resin that forms the covalent bond with the carboxylic add of the reinforcement layer.

7. A method of forming a composite laminate for providing sealing, baffling or reinforcement to a structure, the method comprising:

providing a polymeric reinforcement layer having a surface tension of at least about 35 dynes/cm wherein the reinforcement layer includes a carboxylic acid or an amine chemical functional group;

locating an epoxy-based expandable structural foam material onto the reinforcement layer by a co-extrusion process to form the composite laminate wherein the structural foam material comprises;

i. an epoxy resin;

ii. an epoxy/elastomer adduct, the adduct including about 1;

3 to 3;

1 parts of epoxy to elastomer; and

iii. a core/shell polymer impact modifier;

wherein the epoxy resin forms a covalent bond with the carboxylic acid or amine of the reinforcement layer upon exposure to temperatures greater than 150 °

C;

exposing the composite laminate to a temperature greater than 150 °

C. prior to any activation of the expandable structural foam so that a covalent bond is formed between the reinforcement layer and structural foam;

wherein the covalent bond allows for load transfer from the structural foam to the reinforcement layer to increase the tensile modulus of the composite laminate to;

i. increase the tensile modulus of the composite laminate relative to the structural foam without the reinforcement layer where the difference between the tensile modulus of the composite laminate and the tensile modulus of the structural foam without the reinforcement layer is a range from 154 MPa to 633 MPa post-activation; and

ii. increase the lap shear strength of the composite laminate relative to the structural foam without the reinforcement layer where the difference between the lap shear strength of the composite laminate and the lap shear strength of the structural foam without the reinforcement layer is a range from 0.68 MPa to 1.35 MPa post-activation.

8. The method of claim 7, wherein upon exposure of the composite laminate to temperatures greater than 150 °

C., the covalent bond between the reinforcement layer and the structural foam substantially prevents lateral expansion of the foam so that expansion of the foam is substantially vertical.