Pneumatic tire
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 CW≤SW≤BW1.
1 . A pneumatic tire, comprising:
a tread portion extending in a tire circumferential direction and having an annular shape;
a pair of sidewall portions respectively disposed on both sides of the tread portion;
a pair of bead portions each disposed on an inner side of a respective sidewall portion of the pair of sidewall portions in a tire radial direction;
a carcass layer mounted between the pair of bead portions;
at least one belt layer comprising an inner belt layer disposed adjacent to an outer circumferential side of the carcass layer in the tread portion; and
a sealant layer made of an adhesive sealant provided on at least an inner surface of the tread portion;
a width SW of the sealant layer, a width BW1 of the inner belt layer, and an actual ground contact width CW satisfying a relationship CW≤SW≤BW1;
a thickness T1 of the tread portion and a thickness S1 of the sealant layer at the tire equator position satisfying a relationship 0.15<S1/T1<0.35; and
a thickness T2 of the tread portion and a thickness S2 of the sealant layer at each end portion position of the sealant layer satisfying a relationship 0.20<S2/T2<0.40.
2 . The pneumatic tire according to claim 1 , wherein a vertical distance L along a tire radial direction between a tread surface at a tire equator position and a tread surface at each end portion of an actual ground contact region is 10.0 mm or less.
3 . The pneumatic tire according to claim 1 , wherein the adhesive sealant has a tan δ at 60° C. of 1.0 or less.
4 . The pneumatic tire according to claim 1 , wherein in a sealant composition constituting the adhesive sealant, a proportion A of toluene insoluble in the sealant composition expressed by A=(W2/W1)×100 ranges from 30 mass % to 60 mass %,
where W2 is a mass in grams of toluene insoluble remaining after immersion of the sealant composition in toluene for one week, and W1 is an initial mass in grams before immersion of the sealant composition in toluene.
5 . The pneumatic tire according to claim 1 , wherein, a sealant composition constituting the adhesive sealant comprises from 0.1 parts by mass to 40 parts by mass of a crosslinking agent blended per 100 parts by mass of rubber component.
6 . The pneumatic tire according to claim 5 , wherein the crosslinking agent comprises a sulfur component.
7 . The pneumatic tire according to claim 5 , wherein
the rubber component comprises butyl rubber, and
a blended amount of the butyl rubber per 100 mass % of the rubber component is 10 mass % or more.
8 . The pneumatic tire according to claim 7 , wherein
the butyl rubber comprises chlorinated butyl rubber, and
a blended amount of the chlorinated butyl rubber per 100 mass % of the rubber component is 5 mass % or more.
9 . The pneumatic tire according to claim 5 , wherein from 1 part by mass to 40 parts by mass of an organic peroxide and more than 0 parts by mass and less than 1 part by mass of a crosslinking aid are blended per 100 parts by mass of the rubber component.
10 . The pneumatic tire according to claim 1 , wherein
the belt layer comprises, in addition to the inner belt layer, an outer belt layer disposed adjacent to an outer circumferential side of the inner belt layer, and
the width SW of the sealant layer and a width BW2 of the outer belt layer satisfy a relationship BW2≤SW.
11 . The pneumatic tire according to claim 10 , wherein a vertical distance L along a tire radial direction between a tread surface at a tire equator position and a tread surface at each end portion of an actual ground contact region is 10.0 mm or less.
12 . The pneumatic tire according to claim 11 , wherein the adhesive sealant has a tan δ at 60° C. of 1.0 or less.
13 . The pneumatic tire according to claim 12 , wherein in a sealant composition constituting the adhesive sealant, a proportion A of toluene insoluble in the sealant composition expressed by A=(W2/W1)×100 ranges from 30 mass % to 60 mass %,
where W2 is a mass in grams of toluene insoluble remaining after immersion of the sealant composition in toluene for one week, and W1 is an initial mass in grams before immersion of the sealant composition in toluene.
14 . The pneumatic tire according to claim 13 , wherein, the sealant composition constituting the adhesive sealant comprises from 0.1 parts by mass to 40 parts by mass of a crosslinking agent blended per 100 parts by mass of rubber component.
15 . The pneumatic tire according to claim 14 , wherein the crosslinking agent comprises a sulfur component.
16 . The pneumatic tire according to claim 15 , wherein
the rubber component comprises butyl rubber, and
a blended amount of the butyl rubber per 100 mass % of the rubber component is 10 mass % or more.
17 . The pneumatic tire according to claim 16 , wherein
the butyl rubber comprises chlorinated butyl rubber, and
a blended amount of the chlorinated butyl rubber per 100 mass % of the rubber component is 5 mass % or more.
18 . The pneumatic tire according to claim 17 , wherein from 1 part by mass to 40 parts by mass of an organic peroxide and more than 0 parts by mass and less than 1 part by mass of a crosslinking aid are blended per 100 parts by mass of the rubber component.