The invention relates to silane mixtures comprising a silane of the formula I
(R.sup.1).sub.y(R.sup.2).sub.3-ySi—R.sup.3—(S—R.sup.4).sub.n—S.sub.x—R.sup.5  (I)
and a silane of the formula II
(R.sup.1).sub.y(R.sup.2).sub.3-ySi—R.sup.3—Si(R.sup.1).sub.y(R.sup.2).sub.3-y  (II)
where the molar ratio of silane of the formula I to silane of the formula II is 15:85-90:10. The silane mixture according to the invention can be prepared by mixing the silanes of the formula I and silanes of the formula II.

An object of the present invention is to provide a rubber composition for a tread which is good in the balance between its wet grip performance and its chipping resistance. The rubber composition for a tread comprises 1 to 20 parts by mass of an ethylene-propylene-styrene copolymer and 60 parts by mass or more of a filler comprising a silica based on 100 parts by mass of a rubber component comprising 20 to 50% by mass of a butadiene rubber and 30 to 80% by mass of a styrene butadiene rubber, wherein an elongation at break of the rubber composition is not less than 300% in the atmosphere of 180° C. according to JIS K 6251: 2017.

An object of the present invention is to provide a rubber composition for a tread which is good in the balance between its wet grip performance and its chipping resistance. The rubber composition for a tread comprises 1 to 20 parts by mass of an ethylene-propylene-styrene copolymer and 60 parts by mass or more of a filler comprising a silica based on 100 parts by mass of a rubber component comprising 20 to 50% by mass of a butadiene rubber and 30 to 80% by mass of a styrene butadiene rubber, wherein an elongation at break of the rubber composition is not less than 300% in the atmosphere of 180° C. according to JIS K 6251: 2017.

An object of the present invention is to provide a rubber composition for a tread which is good in the balance between its wet grip performance and its chipping resistance. The rubber composition for a tread comprises 1 to 20 parts by mass of an ethylene-propylene-styrene copolymer and 60 parts by mass or more of a filler comprising a silica based on 100 parts by mass of a rubber component comprising 20 to 50% by mass of a butadiene rubber and 30 to 80% by mass of a styrene butadiene rubber, wherein an elongation at break of the rubber composition is not less than 300% in the atmosphere of 180° C. according to JIS K 6251: 2017.

The invention relates to a sulfur-crosslinkable rubber mixture and to a pneumatic vehicle tire comprising at least one rubber component made of the sulfur-vulcanized rubber mixture.

The rubber mixture contains 10-60 phr (parts by weight, based on 100 parts by weight of the total rubbers in the mixture) of at least one functionalized polybutadiene A,
wherein the functionalized polybutadiene A is functionalized at one chain end with an organosilyl group containing amino groups and/or ammonium groups,
and wherein the functionalized polybutadiene A is functionalized at the other chain end with an amino group, up to 90 phr of at least one further diene rubber and 30-350 phr of at least one filler.

The invention relates to a sulfur-crosslinkable rubber mixture and to a pneumatic vehicle tire comprising at least one rubber component made of the sulfur-vulcanized rubber mixture.

The rubber mixture contains 10-60 phr (parts by weight, based on 100 parts by weight of the total rubbers in the mixture) of at least one functionalized polybutadiene A,
wherein the functionalized polybutadiene A is functionalized at one chain end with an organosilyl group containing amino groups and/or ammonium groups,
and wherein the functionalized polybutadiene A is functionalized at the other chain end with an amino group, up to 90 phr of at least one further diene rubber and 30-350 phr of at least one filler.

Disclosed is a method of preparing a rubber composition comprising the steps of (a) blending in at least one preparatory mixing step at least one natural or synthetic rubbery polymer, a silica filler, a silica coupling agent, and at least one vulcanization accelerator; and (b) subsequently blending therewith in a final mixing step a sulfur curative, wherein the average glass transition temperature of the polymer(s) is −55° C. or less.

Disclosed is a method of preparing a rubber composition comprising the steps of (a) blending in at least one preparatory mixing step at least one natural or synthetic rubbery polymer, a silica filler, a silica coupling agent, and at least one vulcanization accelerator; and (b) subsequently blending therewith in a final mixing step a sulfur curative, wherein the average glass transition temperature of the polymer(s) is −55° C. or less.

Disclosed is a method of preparing a rubber composition comprising the steps of (a) blending in at least one preparatory mixing step at least one natural or synthetic rubbery polymer, a silica filler, a silica coupling agent, and at least one vulcanization accelerator; and (b) subsequently blending therewith in a final mixing step a sulfur curative, wherein the average glass transition temperature of the polymer(s) is −55° C. or less.

A polymeric composition includes a diene elastomer; an azodicarboxy compound; and a reinforcing filler comprising silica. The composition is not foamed. A method for preparing a polymeric composition includes mixing in one or more steps: a diene elastomer; an azodicarboxy compound; and a reinforcing filler. The mixing temperature is less than 160° C. in mixing steps in which the azodicarboxy compound is present. In an embodiment, the mixing temperature is kept below the decomposition temperature of the azodicarboxy compound.