FR2624440A1 - TIRE FOR A RADIAL CARCASS VEHICLE WITH INTERNAL REINFORCING ELEMENTS - Google Patents

Abstract

The invention relates to a tire for a vehicle. In this tire, internal elements or reinforcing layers are provided which contain a vulcanizable rubberized material consisting of epoxidized polyisoprene containing at least 20 mol% of oxirane, which makes it possible to improve the gas impermeability of this material. Application to the transport industry.

Description

The present invention relates to a tire for a vehicle of the type

  radial carcass with reinforcing inserts in the form of an internal reinforcing element of the kind belt, consisting in particular of a metal fabric, and / or a covering layer of fabric, which consists of elements of cable or wire subject to shrinkage under the effect of heat and arranged in a peripheral direction, and / or a layer of rubber located radially above the carcass, the mass formed of the rubber mixture consisting of components elastomers ensuring good impermeability to gases. In a vehicle tire of this type, the belt-shaped internal reinforcing element, in particular consisting of layers of metal fabric, is covered by a textile fabric consisting of wire or cable elements subject to shrinkage under the effect of heat. Other internal reinforcing elements can be provided which prevent the penetration of air containing moisture in the tires. These rubberized materials are suitable for

  good impermeability to gases. In tires -

  for vehicles, air and moisture particles penetrate, depending on the circumstances, from the outside and progress to the internal reinforcing element frequently having metal elements. By means of the known rubberized materials, the penetration of air and moisture particles into this inner reinforcing element is prevented in order to protect it against the disturbing effects of the air and

moisture.

  The object of the invention is to ensure a relatively weak air passage through the

  internal reinforcing or other elements of the pneumatic

  than. This result must be obtained by the use of a

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  elastomer which has been treated, and can be used

  happily, to create a better impermeability to gases. According to the invention, the problem is solved by using as elastomer an epoxy polyisoprene.

  xydé containing at least 20 mol% oxirane.

  By using a rubber modified polyisoprene, good gas impermeability can be imparted to any reinforcing layer or other internal element between the carcass and the tread. As a rubber material for the inner carcass layer, it is known to use epoxidized natural rubber. Owing to its property of great impermeability to gases, the polyisoprene containing oxirane is advantageously superior to the rubberized material for the aforementioned inserts. It protects reinforcing inserts against influences

  possible air and moisture.

  The rubberized material for the inner members may consist solely of the aforementioned epoxidized polyisoprene. It can, however, advantageously

  also contain components of a rubber mix

  Rubber formed of natural rubber and epoxidized polyisoprene. Thus, advantageously, said elastomer components contain at least 20 parts per part epoxidized polyisoprene rubber with at least 20 mol%. of oxirane and at least 20 parts by parts of natural rubber rubber and that other elastomeric components constitute the remaining 60 parts per 100 parts of rubber. This will be explained in more detail later, with

  the corresponding advantages, using an example of embodiment.

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EXAMPLE A E

  Rubber mix Standard compound for a rubberized rubber inner part for inner butyl rubber casing element reinforcement pphr parts / 100 rubber rubber (Part per hundred rubber) Natural rubber 40 pphr 40 pphr

Chlorinated rubber

  butylated 60 pphr ENR 50 = natural rubber containing 50% oxirane mole 60 pphr Carbon black GPF N 660 80 pphr 80 pphr Aromatic oil 6 pphr 6 pphr Stearic acid 1.5 pphr 1.5pphr Zinc oxide 5.0 pphr MBTS Accelerator 0.8 pphr DPG Accelerator 0.1 pphr MBS Accelerator 1.5 pphr Sulfur 1.0 pphr 1.5 pphr Gas Imperviousness Values for Mixtures A and E

A E

 C 1.9 1.7

m2.10-17 were raised

s.Pa v for 50 C 5.2 5.7

 C, 9.6, 10.6

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  By comparing the values obtained, it can be seen that the rubberized material for

  internal strengthening elements is now

  even very impervious to gases, being comparable with the butyl elastomer, considerably more expensive and difficult to implement, for the inner layer of tires. Depending on the selected rubber material, in the case of using the epoxidized polyisoprene; internal strengthening elements

  to obtain an advantageous property in addition to

  both to the desired gas impermeability, namely protection against particle influences

  moisture / air that seep from the outside.

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Claims (2)

  1 - Pneumatic tire for vehicle, type to   radial carcass with reinforcing elements   in the form of a reinforcing element   belt-like internal construction, consisting in particular of a metal fabric, and / or a fabric covering layer, which consists of cable or wire elements subject to heat shrinkage and disposed in a peripheral direction, and / or a layer of rubber located radially above the carcass,   the mass formed of the rubber mixture being   of elastomer components providing good gas impermeability, characterized in that an epoxidized polyisoprene containing less than 20 mol% oxirane.   2 - A tire according to claim 1,   characterized in that the elastomer components contain   at least 20 parts per part of epoxidized polyisoprene rubber with at least 20 mol%. of oxirane and at least 20 parts per 100 parts of rubber   of natural rubber and other elastomeric   re constitute the remaining 60 parts per 100 parts of rubber.