Cross-linked product and tire
A cross-linked product obtained through crosslinking a polymer composition that contains a rubber component, an inorganic filler and a cross-linking agent and that satisfies conditions (a) to (c): (a) the rubber component contains a conjugated diene-based polymer (A) having, when composition ratios (molar ratios) in the conjugated diene-based polymer (A) of structural units represented by formulae (1) to (4) are p, q, r, and s, respectively, a value α represented by formula (i) of 0.80 or more and 0.97 or less; (b) a blending ratio of the conjugated diene-based polymer (A) is 10% by mass or more relative to a total amount of the rubber component; and (c) a blending ratio of the inorganic filler is 40 to 150 parts by mass relative to 100 parts by mass of the rubber component, wherein the Tg of the cross-linked product is −25° C. or lower.
1 . A cross-linked product, obtained by a process comprising crosslinking a polymer composition that comprises a rubber component, an inorganic filler, and a cross-linking agent,
wherein the rubber component comprises a conjugated diene-based polymer (A) having a value α in a range of from 0.80 to 0.97, where a is calculated by formula (i);
α=( p +(0.5× r ))/( p+q +(0.5× r )+ s ) (i),
p is a molar ratio of a structural unit of formula (1);
q is a molar ratio of a structural unit of formula (2);
r is a molar ratio of a structural unit of formula (3);
and
s is a molar ratio of a structural unit of formula (4);
in the conjugated diene-based polymer (A),
wherein a blending ratio of the conjugated diene-based polymer (A) is 10% by mass or more, relative to a total amount of the rubber component,
wherein a blending ratio of the inorganic filler is in a range of from 50 to 150 parts by mass, relative to 100 parts by mass of the rubber component,
wherein the cross-linked product has a glass transition point, Tg, of −25° C. or lower,
wherein the conjugated diene-based polymer (A) is a random copolymer of a conjugated diene compound and an aromatic vinyl compound,
wherein the conjugated diene-based polymer (A) has a content ratio of a structural unit derived from the aromatic vinyl compound in a range of from 3 to 20% by mass, relative to a total monomer unit amount of the conjugated diene-based polymer, and
wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 5 to 28 mol % before hydrogenation.
2 . The cross-linked product of claim 1 , wherein the conjugated diene-based polymer (A) has a functional group that interacts with the inorganic filler.
3 . The cross-linked product of claim 1 , wherein the conjugated diene-based polymer (A) has a Tg of −45° C. or lower.
4 . The cross-linked product of claim 1 , wherein the conjugated diene-based polymer (A) has a melting point of −10° C. or higher, and a heat of fusion of 3 J/g or more, when measured with a differential scanning calorimeter by raising the temperature from −100° C. to 200° C. at 20° C./min.
5 . A method for producing a cross-linked product, the method comprising:
crosslinking a polymer composition that comprises a rubber component, an inorganic filler, and a cross-linking agent,
wherein the rubber component comprises a conjugated diene-based polymer (A) having a value α in a range of from 0.80 to 0.97, where a is calculated by formula (i):
α=( p +(0.5× r )/( p+q +(0.5× r )+ s ) (i),
p is a molar ratio of a structural unit of formula (1);
q is a molar ratio of a structural unit of formula (2);
r is a molar ratio of a structural unit of formula (3);
and
s is a molar ratio of a structural unit of formula (4):
in the conjugated diene-based polymer (A),
wherein a blending ratio of the conjugated diene-based polymer (A) is 10% by mass or more relative to a total amount of the rubber component,
wherein a blending ratio of the inorganic filler is in a range of from 50 to 150 parts by mass relative to 100 parts by mass of the rubber component,
wherein the cross-linked product has a glass transition point, Tg, of −25° C. or lower,
wherein the conjugated diene-based polymer (A) is a random copolymer of a conjugated diene compound and an aromatic vinyl compound,
wherein the conjugated diene-based polymer (A) has a content ratio of a structural unit derived from the aromatic vinyl compound in a range of from 3 to 20% by mass relative to a total monomer unit amount of the conjugated diene-based polymer, and
wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 5 to 28 mol % before hydrogenation.
6 . The method of claim 5 , wherein the conjugated diene-based polymer (A) has a T g of −45° C. or lower.
7 . An all-season tire, comprising:
a tread and/or a sidewall, comprising the cross-linked product of claim 1 .
8 . A winter tire, comprising:
a tread and/or a sidewall, comprising the cross-linked product of claim 1 .
9 . A rubber molded product, comprising:
the cross-linked product of claim 1 ,
wherein the rubber molded product is an anti-vibration member, a belt member, a roll member, a hose member, a wire harness member, or a shoe sole member.
10 . The cross-linked product of claim 2 , wherein the conjugated diene-based polymer (A) has a Tg of −45° C. or lower.
11 . The cross-linked product of claim 2 , wherein the conjugated diene-based polymer (A) has a melting point of −10° C. or higher, and a heat of fusion of 3 J/g or more, when measured with a differential scanning calorimeter by raising the temperature from −100° C. to 200° C. at 20° C./min.
12 . The cross-linked product of claim 3 , wherein the conjugated diene-based polymer (A) has a melting point of −10° C. or higher, and a heat of fusion of 3 J/g or more, when measured with a differential scanning calorimeter by raising the temperature from −100° C. to 200° C. at 20° C./min.
13 . The cross-linked product of claim 1 , wherein the content ratio of the structural unit derived from the aromatic vinyl compound is in a range of from 10 to 20% by mass, relative to the total monomer unit amount of the conjugated diene-based polymer.
14 . The cross-linked product of claim 1 , wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 10 to 28 mol. % before hydrogenation.
15 . The cross-linked product of claim 13 , wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 10 to 23 mol. % before hydrogenation.
16 . The cross-linked product of claim 13 , wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 15 to 28 mol. % before hydrogenation.
17 . The method of claim 5 , wherein the content ratio of the structural unit derived from the aromatic vinyl compound is in a range from 10 to 20% by mass, relative to the total monomer unit amount of the conjugated diene-based polymer.
18 . The method of claim 5 , wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 10 to 28 mol % before hydrogenation.
19 . The method of claim 17 , wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 10 to 23 mol % before hydrogenation.
20 . The method of claim 17 , wherein the conjugated diene-based polymer (A) has a 1,2-vinyl bond content in a range of from 15 to 28 mol % before hydrogenation.