Tyre balancing compositions

Abstract

The invention relates to tyre balancing compositions having improved balancing properties comprise a visco-plastic gel and solid bodies having an average smallest dimension in the range of 0.5-5 mm; preferably 1-4 mm, more preferably around 3 mm. When applied in a layer to the inside of a motor vehicle tyre, the compositions act by allowing the solid bodies move through the gel and to concentrate in areas to counteract imbalances. The solid bodies preferably have an average ratio α between their smallest and their largest dimension of α≦2, more preferably α≦1.5, especially around 1. The visco-plastic gel preferably has a storage modulus (G′) between 1000 Pa and 25000 Pa at 22° C., a loss modulus (G″) smaller than the storage modulus, and a critical yield stress above 3 Pa at 22° C. The bodies may be shaped as prolate or oblate ellipsoids, cylinders, rectangular paralleipipeds, or spheres, or mixtures of such bodies; they may have an apparent specific gravity in the range of 500-3000 kg / m3, preferably 600-2000 kg / m3, in particular 700-1000 kg / m3, especially 800-900 kg / m3; they may be made from polyolefins, polystyrene, polyvinyl chloride, polyamide, rubber or glass. The weight ratio between the solid bodies and the gel is from 10:1 to 1:10, preferably from 5:1 to 1:5, in particular from 2:1 to 3:1, such as from 1:1 to 1:2. The invention further concerns a tyre balancing kit and a method for balancing automobile wheel assemblies.

Description

RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent application Ser. No. 10 / 019,068, filed Apr. 26, 2002 which is a national stage application of International Application No. PCT / DK00 / 00331, filed Jun. 21, 2000 which claims priority to European Application No. 99112199.7, filed Jun. 24, 1999.FIELD OF THE INVENTION

[0002] The present invention relates to tyre balancing compositions for use in eliminating / reducing vibrations in motor vehicle wheel assemblies related to tyre and rim imperfections, as well as to the use of such compositions. BACKGROUND OF THE INVENTION

[0003] Vibrations in rolling wheel assemblies (tyre+rim) are caused by several, different types of tyre imperfections, the most important being:

[0004] Non-homogeneous mass distribution

[0005] Stiffness variations

[0006] Geometric variations

[0007] Radial and lateral run outs

[0008] Eccentricity

[0009] Similarly, imperfections in the rim will also induce vibrations.

[0010] The at present most co...