Thermoplastic elastomer composition, process for producing the same, and pneumatic tire and hose made with the same

• US 6,359,071 B1
• Filed: 12/07/1999
• Issued: 03/19/2002
• Est. Priority Date: 01/13/1998
• Status: Expired due to Term

• Current Assignee: Yokohama Rubber Company Limited
• Original Assignee: Yokohama Rubber Company Limited
• Inventors: Yamauchi, Shigeru, Watanabe, Jiro, Nemoto, Hideo, Hara, Yuichi, Kawazura, Tetsuji, Yamakawa, Kazuto, Kuroda, Noriaki, Kanenari, Daisuke, Kawaguchi, Gou
• Primary Examiner(s): Gorr, Rachel
• Assistant Examiner(s): BISSETT, MELANIE D
• Application Number:
  US09/380,588
• Time in Patent Office: 833 Days
• Field of Search: 525/184, 525/432, 525/431, 525/185, 525/190, 525/199, 525/209, 525/212, 525/238, 536/156
• US Class Current: 525/184
• CPC Class Codes: B60C 1/00 Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
• CPC Class Codes: B60C 1/0008 Compositions of the inner liner
• CPC Class Codes: C08L 23/02 not modified by chemical after-treatment
• CPC Class Codes: C08L 23/283 Halogenated homo- or copolymers of iso-olefins
• CPC Class Codes: C08L 2312/00 Crosslinking
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/20 Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof
• CPC Class Codes: C08L 77/00 Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: Y10T 152/10495 Pneumatic tire or inner tube

Abstract

A thermoplastic elastomer composition dynamically vulcanized to a gelation rate of 50 to 95% which is superior in heat resistance and durability while maintaining flexibility and superior in air permeation preventive property which can be efficiently used as, for example, a pneumatic tire as an air permeation preventive layer. In particular, a thermoplastic elastomer composition having a reduced particle size of the domain rubber is produced by a material having a high rubber ratio by mixing a composition (C) mixed under conditions of a ratio of melt viscosities of the rubber composition (A)/resin (B) of 0.8 to 1.2 and the formula (φ_A/φ_B)×(η_B/η_A)<1.0 under conditions of a ratio of melt viscosities of the rubber composition (D)/composition (C) of 0.8 to 1.2 and the formula (φ_D/φ_C)×(η_C/η_D)<1.0, wherein φ_A: volume fraction of rubber composition (A), φ_B: volume fraction of resin (B), η_A: melt viscosity of rubber composition (A), η_B: melt viscosity of resin (B), φ_C: volume fraction of composition (C), φ_D: volume fraction of rubber composition (D), η_C: melt viscosity of composition (C), η_D: melt viscosity of rubber composition (D).

Claims

1. A thermoplastic elastomer composition comprising an elastomer composition (A′

) as a dispersion phase and a thermoplastic resin composition (B′

) as a matrix, said and having composition (B′

) composed of a blend of at least two thermoplastic resins, wherein the dispersed particle size of the elastomer composition (A′

) is not more than 10 μ

m and the particle size of a resin composition (D′

) dispersed in a matrix resin composition (C′

) in the thermoplastic resin composition (B′

) is smaller than the particle size of the dispersed rubber.

2. A thermoplastic elastomer composition as claimed in claim 1, wherein the elastomer composition (A′

) and the thermoplastic resin composition (B′

) satisfy the following equations (V) and (VI);

3. A thermoplastic elastomer composition as claimed in claim 1 or 2, wherein the elastomer component contained in the elastomer composition (A′

) is at least one elastomer selected from the group consisting of diene rubbers and the hydrates thereof, olefin rubbers, halogen-containing rubbers, silicone rubbers, a sulfur-containing rubbers, a fluoro rubbers, and thermoplastic elastomers.

4. A thermoplastic elastomer composition as claimed in claim 1 or 2, wherein the thermoplastic resin component contained in the thermoplastic resin composition (B′

) is at least one thermoplastic resin selected from the group consisting of polyamide resins, polyester resins, polynitrile resins, polymethacrylate resins, polyvinyl resins, cellulose resins, fluoro resins, and imide resins.

5. A thermoplastic elastomer composition as claimed in claim 1 or 2, wherein a blend of at least two polyamide resins is selected as the thermoplastic resin composition (B′

).

6. A thermoplastic elastomer composition as claimed in claim 1 or 2, wherein a polyamide resin having at least seven methylene groups with respect to one amide group is contained as the matrix resin composition (C′

) in the thermoplastic resin composition (B′

) and a polyamide resin having less than seven methylene groups with respect to one amide group is contained as the dispersed resin composition (D′

).

7. A pneumatic tire comprising a thermoplastic elastomer composition as claimed in of claim 1 or 2 as an air permeation preventive layer.

8. A hose comprising a thermoplastic elastomer composition according to claim 1 or 2 as at least one of a hose outer tube material adjacent to a reinforcing layer, an inner layer material of an inner tube, an outer layer material of an inner tube, and a space between reinforcing layers.