Heat-fusible-expandable mastic for automobile floor pans

• US 4,495,240 A
• Filed: 04/16/1984
• Issued: 01/22/1985
• Est. Priority Date: 12/31/1981
• Status: Expired due to Fees

• Current Assignee: Lafayette Automotive Industrial Corporation
• Original Assignee: USM Corporation
• Inventors: McCarthy, Bruce C.
• Primary Examiner(s): Foelak, Morton
• Application Number:
  US06/600,781
• Time in Patent Office: 281 Days
• Field of Search: 521/83, 521/134, 521/140, 428/319.1, 428/355, 428/489
• US Class Current: 428/319.1
• CPC Class Codes: B60R 13/08 Insulating elements, e.g. for sound insulation sound insulating linings for trains B61D17/185; drivers' cabs for load-carrying vehicles insulated against vibrations or noise B62D33/0604; thermal or acoustic insulation of engines F02B77/11; damping of sounds using compensation by electro-acoustic methods G10K11/178
• CPC Class Codes: B60R 13/0815 Acoustic or thermal insulation of passenger compartments wall or roof liners integrating the insulating function B60R13/02; insulating floor mats or carpets B60N3/04
• CPC Class Codes: B60R 13/083 for fire walls or floors
• CPC Class Codes: C08J 9/0061 characterized by the use of several polymeric components
• CPC Class Codes: C08L 95/00 Compositions of bituminous materials, e.g. asphalt, tar, pitch
• CPC Class Codes: Y10T 428/24999 Inorganic
• CPC Class Codes: Y10T 428/2857 including metal or compound thereof or natural rubber
• CPC Class Codes: Y10T 428/2878 including addition polymer from unsaturated monomer
• CPC Class Codes: Y10T 428/2883 including addition polymer of diene monomer [e.g., SBR, SIS, etc.]
• CPC Class Codes: Y10T 428/31815 Of bituminous or tarry residue

Abstract

The invention relates to a relatively inexpensive, non-blocking, low density sound deadening mastic material. Essentially, the composition of the improved sound deadening mastic material of this invention includes a mineral filler, an elastomer, a polymeric modifier and a foaming (or blowing) agent. The mastic material is particularly useful in sheet form for automotive applications.

Claims

1. A laminate comprising a mastic sheet material softenable into conformnity with a contoured metal surface but resistant to flow and comprising from about 25 to about 65 percent by weight of the mastic material of mineral filler, from about 2 to about 15 percent by weight of an elastomer, from about 2 to about 20 percent by weight of asphalt from about 20 to about 60 percent by weight of a polymeric modifier and an effective amount of a heat activatable foaming agent and a substrate bonded to at least on surface of the mastic sheet material.

2. A laminate of claim 1 where the mastic sheet material has been heated to activate the blowing agent and expand the mastic sheet material.

6. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where said polymeric modifier of said mastic sheet material includes from about 1 to about 5 percent by weight gilsonite.

7. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where the mastic sheet material comprises from about 35 to about 60 percent by weight of mineral filler, from about 7 to about 12 percent by weight elastomer from about 4 to about 16 percent by weight asphalt, from about 30 to about 50 percent by weight of polymeric modifier including from about 1.5 to about 3.5 percent by weight gilsonite and from about 0.5 to about 3 percent by weight of a heat activatable foaming agent.

8. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where said elastomer of said mastic sheet material includes a reclaim rubber and a rubber selected from the group consisting of ethylene propylene rubbers, ethylene propylene diene rubbers or mixtures of these.

9. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where said polymeric modifier of said mastic sheet material includes an ethylene polymer.

10. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where said polymeric modifier of said mastic sheet material includes a polyethylene polymer.

11. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where said polymeric modifier of said mastic sheet material includes an ethylene polymer selected from the group consisting of polyethylene, ethylene ethyl acrylate or mixtures of these.

12. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where said foaming agent has a decomposition temperature between about 140°

C. to about 200°

C.

13. A laminate of claim 1 or claim 2 or claim 3 or claim 4 or claim 5 where said mineral filler includes a finely divided dolomitic limestone.

3. A laminate comprising a mastic sheet material softenable into conformnity with a contoured metal surface but resistant to flow and comprising from about 25 to about 65 percent by weight of the mastic material of mineral filler, from about 2 to about 15 percent by weight of an elastomer, from about 2 to about 20 percent by weight of asphalt from about 20 to about 60 percent by weight of a polymeric modifier and an effective amount of a heat activatable foaming agent and, a non-foamable sound deadening sheet material.

4. A laminate of claim 3 where the non-foamable sound deadening sheet material is bonded to one surface of the mastic sheet material.

5. A laminate of claim 3 where the sheet material has been expanded to activate the blowing agent and expand the mastic sheet material and where the non-foamable sound deadening sheet material is bonded to one surface of the mastic sheet material and a substrate is bonded to one surface of the foamable sheet material.