Modified conjugated diene-based polymer, polymer composition, and rubber composition
A modified conjugated diene-based polymer having a weight average molecular weight of 20×10 4 or more and 300×10 4 or less, and having a molecular weight distribution Mw/Mn of 1.6 or more and 4.0 or less, wherein a modification ratio with respect to a total amount of the conjugated diene-based polymer is 50% by mass or more, a modification ratio of a component having a molecular weight which is ½ of a molecular weight at a peak top, or a peak top of the minimum molecular weight when a plurality of the peak tops of molecular weights is present, in a gel permeation chromatography curve is ½ or more of the modification ratio with respect to the total amount of the conjugated diene-based polymer, and a content of nitrogen contained in the modified conjugated diene-based polymer is 3 mass ppm or more and 70 mass ppm or less.
1. A modified conjugated diene-based polymer:
having a weight average molecular weight of 20×10 4 or more and 300×10 4 or less, and having a molecular weight distribution Mw/Mn of 1.6 or more and 4.0 or less, wherein a modification ratio with respect to a total amount of the conjugated diene-based polymer is 50% by mass or more,
a modification ratio of a component having a molecular weight which is ½ of a molecular weight at a peak top, or a peak top of the minimum molecular weight when a plurality of the peak tops of molecular weights is present, in a gel permeation chromatography (GPC) curve is
½ or more of the modification ratio with respect to the total amount of the conjugated diene-based polymer,
a content of nitrogen contained in the modified conjugated diene-based polymer is 3 mass ppm or more and 70 mass ppm or less, and
the modified conjugated diene-based polymer is a copolymer of a conjugated diene compound and a vinyl-substituted aromatic compound.
2. The modified conjugated diene-based polymer according to claim 1 , wherein a shrinkage factor (g′) measured by 3D-GPC is 0.86 or more and 1.0 or less.
3. The modified conjugated diene-based polymer according to claim 1 , wherein a shrinkage factor (g′) measured by 3D-GPC is 0.30 or more and less than 0.86.
4. The modified conjugated diene-based polymer according to claim 3 , wherein a shrinkage factor (g′) measured by 3D-GPC is 0.30 or more and 0.70 or less.
5. The modified conjugated diene-based polymer according to claim 1 , wherein
each of contents of nitrogen and silicon contained in the modified conjugated diene-based polymer is 3 mass ppm or more, and
a molar ratio of nitrogen to silicon is 1.1 or more and less than 10.
6. The modified conjugated diene-based polymer according to claim 1 , wherein
each of contents of nitrogen and silicon contained in the modified conjugated diene-based polymer is 3 mass ppm or more, and
a molar ratio of nitrogen to silicon is 0.1 or more and less than 0.9.
7. The modified conjugated diene-based polymer according to claim 1 , wherein
a glass transition temperature of the modified conjugated diene-based polymer is −20° C. or more and 0° C. or less.
8. The modified conjugated diene-based polymer according to claim 1 , wherein
a glass transition temperature of the modified conjugated diene-based polymer is −50° C. or more and less than −20° C.
9. The modified conjugated diene-based polymer according to claim 1 , wherein
a glass transition temperature of the modified conjugated diene-based polymer is −70° C. or more and less than −50° C.
10. A polymer composition comprising 10% by mass or more of the modified conjugated diene-based polymer according to claim 1 .
11. A rubber composition comprising:
100 parts by mass of a rubber-like polymer containing 10% by mass or more of the modified conjugated diene-based polymer according to claim 1 ; and
5 to 150 parts by mass of a filler.