A rubber compound for the preparation of portions of pneumatic tyres comprising a cross-linking unsaturated chain polymer base, a filler system and a vulcanization system. The filler system comprises (a) a first carbon black having a surface area less than or equal to 170 m.sup.2/gr in a quantity greater than or equal to 25 phr; (b) a second carbon black having a surface area greater than or equal to 250 m.sup.2/gr in a quantity such that the ratio between the quantity of the first carbon black and the quantity of the second carbon black is greater than or equal to 3 and less than or equal to 10; (c) a carbon black dispersing agent in a quantity of less than or equal to 1 phr.

A rubber compound for the preparation of portions of pneumatic tyres comprising a cross-linking unsaturated chain polymer base, a filler system and a vulcanization system. The filler system comprises (a) a first carbon black having a surface area less than or equal to 170 m.sup.2/gr in a quantity greater than or equal to 25 phr; (b) a second carbon black having a surface area greater than or equal to 250 m.sup.2/gr in a quantity such that the ratio between the quantity of the first carbon black and the quantity of the second carbon black is greater than or equal to 3 and less than or equal to 10; (c) a carbon black dispersing agent in a quantity of less than or equal to 1 phr.

A rubber compound for the preparation of portions of pneumatic tyres comprising a cross-linking unsaturated chain polymer base, a filler system and a vulcanization system. The filler system comprises (a) a first carbon black having a surface area less than or equal to 170 m.sup.2/gr in a quantity greater than or equal to 25 phr; (b) a second carbon black having a surface area greater than or equal to 250 m.sup.2/gr in a quantity such that the ratio between the quantity of the first carbon black and the quantity of the second carbon black is greater than or equal to 3 and less than or equal to 10; (c) a carbon black dispersing agent in a quantity of less than or equal to 1 phr.

Provided are: an acrylic adhesive sheet having a porous structure including a plurality of pores and having a water vapor transmission rate of 2,000 g/m.sup.2.Math.24 h to 3,500 g/m.sup.2.Math.24 h at 24° C. and 25% RH, and a porosity of 10% to 60%; and a medical adhesive tape including the same.

Provided is a rubber composition comprising: a rubber component containing diene-based rubber; a filler, and a compound represented by formula (I) below: ##STR00001##
(wherein: A is an aryl group and has at least two polar groups, which may be the same or different from each other; R.sup.1 and R.sup.2 are each independently at least one substituent selected from a group consisting of a hydrogen atom, an acyl group, an amide group, an alkyl group, a cycloalkyl group, and an aryl group; and further, the substituent may include one or more of O, S, and N atoms), so as to provide a rubber composition excellent in low heat generating property and wear resistance.

Provided is a rubber composition comprising: a rubber component containing diene-based rubber; a filler, and a compound represented by formula (I) below: ##STR00001##
(wherein: A is an aryl group and has at least two polar groups, which may be the same or different from each other; R.sup.1 and R.sup.2 are each independently at least one substituent selected from a group consisting of a hydrogen atom, an acyl group, an amide group, an alkyl group, a cycloalkyl group, and an aryl group; and further, the substituent may include one or more of O, S, and N atoms), so as to provide a rubber composition excellent in low heat generating property and wear resistance.

Provided is a rubber composition comprising: a rubber component containing diene-based rubber; a filler, and a compound represented by formula (I) below: ##STR00001##
(wherein: A is an aryl group and has at least two polar groups, which may be the same or different from each other; R.sup.1 and R.sup.2 are each independently at least one substituent selected from a group consisting of a hydrogen atom, an acyl group, an amide group, an alkyl group, a cycloalkyl group, and an aryl group; and further, the substituent may include one or more of O, S, and N atoms), so as to provide a rubber composition excellent in low heat generating property and wear resistance.

An object of the present invention is to provide novel crystals. Provided are crystals of 3-hydroxy-N′-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide having an X-ray powder diffraction pattern comprising a peak of maximum intensity at an angle of diffraction (2θ) of 6.1±0.2°.

An object of the present invention is to provide novel crystals. Provided are crystals of 3-hydroxy-N′-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide having an X-ray powder diffraction pattern comprising a peak of maximum intensity at an angle of diffraction (2θ) of 6.1±0.2°.

An object of the present invention is to provide novel crystals. Provided are crystals of 3-hydroxy-N′-(1,3-dimethylbutylidene)-2-naphthoic acid hydrazide having an X-ray powder diffraction pattern comprising a peak of maximum intensity at an angle of diffraction (2θ) of 6.1±0.2°.