Disclosed is a self-healing acrylic copolymer represented by Formula 1: ##STR00001## The acrylic copolymer can self-heal structural damages such as scratches with the aid of heat and water and possesses excellent physical properties at room temperature. Also disclosed is a crosslinked copolymer prepared from the acrylic copolymer.

The present disclosure relates to self-healing siloxane elastomers. In particular, the present disclosure relates to self-healing siloxane elastomers comprising at least one siloxane polymer reversibly crosslinked to a second siloxane oligomer or polymer.

In a pneumatic tire including belt layers on an outer circumferential side of a carcass layer in a tread portion and a sealant layer made of an adhesive sealant provided on an inner surface of the tread portion, a width SW of the sealant layer, a width BW1 of an inner belt layer disposed adjacent to the carcass layer of the belt layers, and an actual ground contact width CW satisfy a relationship CWSWBW1.

A sealant material composition forming a sealant layer of a pneumatic tire provided with the sealant layer on a tire inner surface is prepared by blending from 1 part by mass to 40 parts by mass of a crosslinking aid and from 50 parts by mass to 400 parts by mass of a liquid isobutylene-isoprene copolymer having a molecular weight from 10000 to 60000 per 100 parts by mass of a halogenated butyl rubber.

As the sealant material composition forming a sealant layer of a pneumatic tire provided with the sealant layer on a tire inner surface, the sealant material composition prepared by blending from 0.1 parts by mass to 20 parts by mass of a crosslinking agent, from 0.1 parts by mass to 40 parts by mass of an organic peroxide, and from 10 parts by mass to 400 parts by mass of a liquid polymer per 100 parts by mass of a butyl rubber is used.

The present invention is directed to a method making a pneumatic tire, comprising the steps of: mixing a sealant composition comprising an elastomer, a filler, a diluent, a quinoid curing agent, an oxidant co-curative; and a cure modifier of formula 1: ##STR00001##
wherein R.sup.1 and R.sup.2 are independently H or C1 to C4 alkyl, or R.sup.1 and R.sup.2 taken together form a substituted or unsubstituted phenylene group; R.sup.3 and R.sup.4 are independently H, NH.sub.2, C1 to C4 alkyl, or OR.sup.5 where R.sup.5 is C1 to C4 alkyl, with the proviso that when R.sup.1 and R.sup.2 are taken together to form a substituted or unsubstituted phenylene group, R.sup.5 is C1 to C3 alkyl; applying the sealant composition to an inner surface of a cured tire; and curing the sealant composition.

Provided is a pneumatic tire in which a sealant layer entirely exhibits sufficient sealing performance. The present invention relates to a pneumatic tire including a sealant layer located radially inside an innerliner, the sealant layer being formed by continuously and spirally applying a generally string-shaped sealant to the inner periphery of a tire in the tire width direction from one side to the other, the attachment start portion of the sealant being located tire-widthwise inward from the tire-widthwise end of the sealant layer.

A puncture sealing agent is disclosed which comprises natural rubber latex, an aqueous solution of an adhesive, and an antifreezing agent. The natural rubber latex, the aqueous solution of the adhesive and the antifreezing agent are natural components and the adhesive is a carbohydrate.

The present invention relates to: a sealing gel having a Mooney viscosity (ML1+4 @ 100 C.) in the range from 100 MU to 170 MU, a sealing compound comprising inventive sealing gel, a process for producing this sealing compound, the use of sealing gels for improving viscoelastic properties in sealing compounds, and the use of sealing gel-containing sealing compounds for improving rolling resistance properties in tyres having sealing layers.

Sealing composition for repairing tyres comprising: from 5% to 15% of natural latex; from 20% to 60% synthetic latex; from 30% to 60% of a glycol selected from the group consisting of propylene glycol and ethylene glycol; from 0.05% to 5% of silica; the synthetic latex comprising from 15% to 40% of ethylene-vinyl acetate, the percentages being by weight of the total composition.