Shape memory foam material

• US 20040164499A1
• Filed: 02/25/2004
• Published: 08/26/2004
• Est. Priority Date: 08/29/2000
• Status: Abandoned Application

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Niwa, Takahiro, Nishimoto, Kazuo, Murakami, Atsushi, Arisawa, Takumi
• Application Number:
  US10/785,187
• Publication Number:
  US 20040164499A1
• Time in Patent Office: Days
• US Class Current: 277/628
• CPC Class Codes: B29C 43/003 characterised by the choice of material
• CPC Class Codes: B29C 44/185 Starting the expansion after rupturing or dissolving the bag
• CPC Class Codes: B29C 61/0608 characterised by the configuration or structure of the preforms
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: B29K 2995/0002 insulating
• CPC Class Codes: B29K 2995/0015 Insulating
• CPC Class Codes: B29L 2031/3041 Trim panels
• CPC Class Codes: F02B 77/13 Acoustic insulation
• CPC Class Codes: Y10T 428/249958 Void-containing component is synthetic resin or natural rubbers
• CPC Class Codes: Y10T 428/249991 Synthetic resin or natural rubbers

Abstract

A shape memory foam material is obtained by impregnating a base foam material in a thermoplastic substance, heating and compressing the same at a temperature the same as or higher than the softening temperature of a thermoplastic substance as well as less than the softening temperature of the base foam material, cooling down while retaining the compressed state, and releasing the pressure after the cooling operation. The compressed state of the shape memory foam material is retained in a room temperature by a hardened product of a thermoplastic substance existing at least in the surface layer part thereof. The compressed state is released by softening the hardened product by heating. Moreover, a soundproof cover for an automobile engine is obtained using this shape memory foam.

Claims

1. A shape memory foam material comprising:

a base foam material; and

a thermoplastic substance impregnated in said base foam material and having a melting point lower than that of said base foam material,

wherein said shape memory foam material is a composite material obtained by compressing said base foam material and said thermoplastic substance, and

wherein a compressed state of said shape memory foam material is retained in a room temperature by a hardened product of said thermoplastic substance existing at least in the surface layer part thereof, and

wherein the compressed state is released by softening said hardened product of said thermoplastic substance by heating.

2. The shape memory foam material according to claim 1, wherein a volume of said base foam material is recovered in 70% or more of an uncompressed state thereof by heating.

3. The shape memory foam material according to claim 1, wherein a thickness of said base foam material is retained in a half or less of an uncompressed state thereof in a room temperature.

4. The shape memory foam material according to claim 1, wherein said base foam material is made of one of a thermosetting resin and a cross-linked rubber.

5. The shape memory foam material according to claim 1, wherein said base foam material is made of urethane.

6. The shape memory foam material according to claim 1, wherein said base foam material in an uncompressed state has a water absorption coefficient of 0.2 g/cm³ or more, and a bulk density of 100 kg/m³ or less.

7. The shape memory foam material according to claim 1, wherein said thermoplastic substance is a thermoplastic resin wherein at least one of a glass transition point, a melting point, and a softening temperature is less than 120°

C.

8. The shape memory foam material according to claim 7, wherein said thermoplastic resin contains at least one selected from the group consisting of an acrylate, a styrene, and a vinyl acetate as a monomer unit.

9. A method of producing a shape memory foam material, comprising the steps of:

impregnating a base foam material in a thermoplastic substance;

heating and compressing said impregnated base foam material at a temperature the same as or higher than a softening temperature of said thermoplastic substance as well as less than a softening temperature of said base foam material;

cooling down said impregnated base foam material while retaining the compressed state; and

releasing the pressure after cooling.

10. A soundproof cover for an automobile engine, comprising a shape memory foam material including:

a base foam material; and

a thermoplastic substance impregnated in said base foam material and having a melting point lower than that of said base foam material,

wherein said shape memory foam material is a composite material obtained by compressing said base foam material and said thermoplastic substance, and

wherein a compressed state of said shape memory foam material is retained in a room temperature by a hardened product of said thermoplastic substance existing at least in the surface layer part thereof, and

wherein the compressed state is released by is softening said hardened product of said thermoplastic substance by heating.