JP2005194317A - Rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition which can achieve high barrier properties while maintaining flexiblity, an inner liner composition for tires using the rubber composition, and an aqueous or solvent-based coating rubber composition. <P>SOLUTION: The rubber composition comprises a rubber containing ≥60 wt.% butyl rubber and a flaky metal. The inner liner rubber composition for tires comprises a rubber containing ≥60 wt.% butyl rubber and a flaky metal in an amount of 5-400 pts.wt. based on 100 pts.wt. entire rubber amount. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rubber composition excellent in gas barrier properties and use of the rubber composition in an inner liner rubber composition or a coating rubber composition.

  In order to produce a tire inner liner having a high gas barrier property, it is known to mix various layered minerals and scale-like minerals with a rubber having a high gas barrier property such as butyl rubber (for example, JP-A-6-116439). No., JP-A-11-140234, JP-A-2002-88206, and JP-A-2002-88208). However, the effect is not yet satisfactory, and a rubber composition having higher gas barrier properties is desired.

JP-A-6-116439 JP-A-11-140234 JP 2002-88206 A JP 2002-88208 A

  Accordingly, the present invention provides a rubber composition capable of achieving high barrier properties while maintaining flexibility, an innerliner composition for tires using the rubber composition, and an aqueous or solvent-based coating rubber composition. With the goal.

  According to this invention, the rubber composition formed by mix | blending a flaky metal with the rubber | gum containing 60 weight% or more of butyl rubber is provided. Further, according to the present invention, an inner liner rubber composition for tires obtained by blending a rubber containing 60% by weight or more of butyl rubber with 5 to 400 parts by weight of a flaky metal with respect to 100 parts by weight of the rubber, A solvent-based coating rubber composition is provided.

  In the present invention, it has been found that when metal flakes are blended with rubber instead of various conventional layered minerals and scale-like minerals, a rubber composition having flexibility and excellent gas barrier properties can be obtained.

  As the rubber component in the rubber composition of the present invention, butyl rubber having a good gas barrier property is used. In addition to butyl rubber (IIR), brominated butyl rubber (Br-IIR), chlorinated butyl rubber (Cl-IIR), brominated isobutylene-p-methylstyrene copolymer rubber (BIMS) and the like are used as the butyl rubber. Among these, from the viewpoint of obtaining a sufficient vulcanization rate, it is preferable to use brominated butyl rubber.

  Examples of metal flakes blended in the rubber composition of the present invention include aluminum flakes, flat Fe-Ni alloy flakes, flat Fe-Si alloy flakes, copper flakes, nickel flakes, chrome flakes, titanium flakes, and zinc flakes. , Iron flakes, bronze flakes, stainless steel flakes, and the like. Among them, aluminum flakes are preferably used for reasons such as specific gravity.

  The average particle diameter of the metal flakes for obtaining gas barrier properties blended in the rubber composition of the present invention is 1 to 100 μm, more preferably 3 to 50 μm, and the average thickness is 0.01 to 5 μm, more preferably 0. 0.02 to 2 μm is suitable. On the surface of the metal flakes, substances other than orthophosphoric monoesters and / or orthophosphoric diesters of aliphatic alcohols, such as fatty acids (oleic acid, stearic acid, etc.), aliphatic amines, fatty acid amides, fatty acid alcohols, ester compounds, etc. May be adsorbed. Further, colored metal flakes that are colored by forming another colored pigment layer, an interference film or the like on the surface of the metal flakes may be used. Further, the blending amount of the metal flakes is 5 to 400 parts by weight, preferably 10 to 300 parts by weight, in a range that maintains the flexibility and gas barrier properties of the resulting rubber composition and does not impair other rubber properties. Part.

  The rubber composition of the present invention further includes ordinary reinforcing agents such as carbon black, vulcanization or cross-linking agents, vulcanization or cross-linking accelerators, various oils, anti-aging agents, fillers, plasticizers, and other general rubbers. It is possible to blend various additives and compounding agents that are generally blended for use, and such blends can be kneaded and vulcanized by a general method to form a rubber composition, which can be vulcanized or crosslinked. it can. The blending amounts of these additives and blending agents can be set to conventional conventional amounts as long as they do not contradict the purpose of the present invention.

  Hereinafter, although an example and a comparative example explain the present invention further, it cannot be overemphasized that the scope of the present invention is not limited to these examples.

Test Method 1) Breaking property: M300 (300% modulus) was measured according to JIS K6251.
2) Air permeability: Measured at 70 ° C. according to JIS K7126 using a gas permeability measuring device MT-C3 manufactured by Toyo Seiki.

Examples 1-6 and Comparative Examples 1-3
In Comparative Example 1 and Examples 1 to 4, the rupture characteristics and the air permeability of the vulcanized rubber sheet having a thickness of 0.5 mm composed of the respective examples were measured. In Comparative Examples 2 and 3 and Examples 5 and 6, a coating film composed of the composition of each example was formed on a vulcanized rubber sheet having a thickness of 0.5 mm composed of composition obtained by removing mica from the composition of Comparative Example 1. After coating and drying (film thickness 0.1 mm), the air permeability was measured.
The results are shown in Table 1.

  According to the results in Table 1, the rubber composition containing a predetermined amount of the metal flakes of the present invention has a remarkable gas barrier property while maintaining its elastic properties as compared with the conventional composition containing layered mica. It can be seen that it has improved.

  Therefore, the rubber composition of the present invention can be effectively applied to a tire inner liner, a coating agent composition, and the like that require gas barrier properties.

Claims (4)

  A rubber composition comprising a rubber containing 60% by weight or more of butyl rubber and a flaky metal.   An inner liner rubber composition for tires, comprising a rubber containing 60% by weight or more of butyl rubber and 5 to 400 parts by weight of a flaky metal with respect to 100 parts by weight of the total rubber.   An aqueous or solvent-based coating rubber composition comprising a rubber containing 60% by weight or more of butyl rubber and 5 to 400 parts by weight of a flaky metal based on 100 parts by weight of the total rubber.   The rubber composition according to any one of claims 1 to 3, wherein the flaky metal is aluminum flakes.