RUBBER MIXTURES WITH IMPROVED PROPERTIES
The invention relates to a rubber mixture comprising rubber and a liquid polybutadiene, liquid at a temperature of 20° C. and a pressure of 98.0665 kPa, wherein the liquid polybutadiene only consists of C— and H-atoms, and has an average molecular weight (Mw), determined by gel permeation chromatography as described in the description, of from 1500 to 5000 g/mol, to a process for preparing rubber articles by vulcanization using the inventive rubber mixtures as raw material, and to rubber articles obtained by this process.
1 . A rubber mixture comprising rubber and a liquid polybutadiene, liquid at a temperature of 20° C. and a pressure of 98.0665 kPa, wherein the liquid polybutadiene comprises the 1,3-butadiene-derived monomer units
and
and wherein the proportion of A in the entirety of the 1,3-butadiene-derived monomer units present in the liquid polybutadiene is from 55 to 70 mol % and wherein the sum of the proportions of B and C in the entirety of the 1,3-butadiene-derived monomer units present in the liquid polybutadiene is from 30 to 45 mol %, and that the liquid polybutadiene only consists of C-and H-atoms, and has an average molecular weight (Mw), determined by gel permeation chromatography as described in the description, of from 1500 to 5000 g/mol.
2 . The rubber mixtures according to claim 1 , wherein said mixtures comprise 0 to 150 parts by wt of precipitated silica, 0 to 100 parts by wt of carbon black and 1 to 50 parts by wt of the liquid polybutadiene, in each case based on 100 parts by weight of rubber.
3 . The rubber mixtures according to claim 1 , wherein said mixtures comprise an organosilane.
4 . The rubber mixtures according to claim 3 , wherein said mixtures comprise 0.5 to 20 parts by wt of organosilane based on 100 parts by wt of rubber.
5 . The rubber mixtures according to claim 14 , wherein said rubber is one kind of rubber or a mixture of different kinds of rubbers.
6 . The rubber mixtures according to claim 15 , wherein said rubber is selected from natural rubber and/or synthetic rubber.
7 . The rubber mixtures according to claim 5 , wherein said rubber is a mixture of Nd-BR and S-SBR.
8 . The rubber mixtures according to claim 1 , wherein said liquid polybutadiene has an average molecular weight (Mw), determined by gel permeation chromatography, of from 1750 to 3500 g/mol.
9 . A process for preparing rubber articles by vulcanization of rubber mixtures, wherein a rubber mixture as claimed in claim 1 is used as raw material.
10 . The rubber articles obtained by a process as claimed in claim 9 .
11 . The rubber articles according to claim 10 , wherein it is a tire or a part of a tire.
12 . The rubber articles according to claim 11 , wherein it is a tire tread.
13 . The rubber articles according to claim 11 , wherein the tire is an all-season tire or a snow (winter) tire.