A conjugated diene-based polymer including at least conjugated diene monomer units, and having a shrinkage factor of high molecular weight molecules of 0.4 to 0.8, a degree of adsorption of high molecular weight molecules onto silica of 75% or less, and a degree of adsorption of medium molecular weight molecules of 40 to 100%.

Provided are a terminally modified diene-based polymer having excellent mechanical properties, and also a method for producing the same. The terminally modified diene-based polymer is obtainable by allowing a diene-based polymer terminated with ketone or aldehyde groups to react with a heterocyclic compound that is a nitrogen-containing unsaturated five-membered ring or six-membered ring compound having a primary amine.

Provided are a terminally modified diene-based polymer having excellent mechanical properties, and also a method for producing the same. The terminally modified diene-based polymer is obtainable by allowing a diene-based polymer terminated with ketone or aldehyde groups to react with a heterocyclic compound that is a nitrogen-containing unsaturated five-membered ring or six-membered ring compound having a primary amine.

Provided are a terminally modified diene-based polymer having excellent mechanical properties and also a method for producing the same. The terminally modified diene-based polymer is obtainable by allowing a diene-based polymer terminated with ketone or aldehyde groups to react with an aminophosphonic acid compound represented by general formula (1) or (2):

##STR00001##

wherein in formulas (1) and (2), R.sub.1 and R.sub.4 each represent a C.sub.1-10 alkanediyl group, R.sub.2 and R.sub.3 may be the same or different and each represent hydrogen, a C.sub.1-3 alkyl group, or a phenyl group, R.sub.5, R.sub.6, R.sub.8, and R.sub.9 may be the same or different and each represent hydrogen, a C.sub.1-3 alkyl group, or a phenyl group, and R.sub.7 represents hydrogen or a hydroxyl group.

Provided are a terminally modified diene-based polymer having excellent mechanical properties and also a method for producing the same. The terminally modified diene-based polymer is obtainable by allowing a diene-based polymer terminated with ketone or aldehyde groups to react with an aminophosphonic acid compound represented by general formula (1) or (2):

##STR00001##

wherein in formulas (1) and (2), R.sub.1 and R.sub.4 each represent a C.sub.1-10 alkanediyl group, R.sub.2 and R.sub.3 may be the same or different and each represent hydrogen, a C.sub.1-3 alkyl group, or a phenyl group, R.sub.5, R.sub.6, R.sub.8, and R.sub.9 may be the same or different and each represent hydrogen, a C.sub.1-3 alkyl group, or a phenyl group, and R.sub.7 represents hydrogen or a hydroxyl group.

The present invention relates to a rubber composition having excellent abrasion resistance and improved tensile properties and viscoelasticity properties by controlling compatibility among rubber components, and a tire manufactured using the same.

The present invention relates to a rubber composition having excellent abrasion resistance and improved tensile properties and viscoelasticity properties by controlling compatibility among rubber components, and a tire manufactured using the same.

The present invention provides a conjugated diene-based polymer excellent in processability in vulcanization, and excellent in abrasion resistance and a low hysteresis loss property of a vulcanizate obtained therefrom. The present invention relates to a conjugated diene-based polymer, having a branch number measured by viscosity detector-equipped GPC-light scattering measurement of 7 or more, an amount of bound aromatic vinyl of 1% by mass or more and 32% by mass or less, and a content of vinyl bond in bound conjugated diene of 11% by mol or more and 35% by mol or less.

The present invention relates to a conjugated diene-based polymer or a modified conjugated diene-based polymer, which has excellent wet skid resistance and abrasion resistance in a balanced way, and a rubber composition including the same, and by controlling the microstructure of the polymer such that a full width at half maximum (FWHM) value of a tan δ peak shown in a temperature range of -100° C. to 100° C. becomes 20° C. or higher in a tan δ graph in accordance with temperature, derived from dynamic viscoelasticity analysis by an Advanced Rheometric Expansion System (ARES), excellent viscoelasticity behavior properties may be shown, and accordingly, the improvement of overall physical properties may be expected.

The present invention relates to a conjugated diene-based polymer or a modified conjugated diene-based polymer, which has excellent wet skid resistance and abrasion resistance in a balanced way, and a rubber composition including the same, and by controlling the microstructure of the polymer such that a full width at half maximum (FWHM) value of a tan δ peak shown in a temperature range of -100° C. to 100° C. becomes 20° C. or higher in a tan δ graph in accordance with temperature, derived from dynamic viscoelasticity analysis by an Advanced Rheometric Expansion System (ARES), excellent viscoelasticity behavior properties may be shown, and accordingly, the improvement of overall physical properties may be expected.