ORGANOPOLYSILOXANE, RUBBER COMPOUNDING AGENT, RUBBER COMPOSITION, AND TIRE

Abstract

Provided are: an organopolysiloxane capable of achieving intended low fuel consumption properties and significantly reducing hysteresis loss in the cured product of a rubber composition during tire production; a rubber compounding agent comprising said organopolysiloxane; a rubber composition obtained by blending said rubber compounding agent; and a tire formed using said rubber composition. The organopolysiloxane, which is represented by average compositional formula (1), is characterized in: containing an organic group with a sulfide group; and the sulfide equivalents being 1,000 g/mol or less.

(A).sub.a(B).sub.b(C)c(R.sup.1).sub.dSiO.sub.(4-2a-b-c-d)/2 (1)

(In the formula, A is a sulfide group-containing divalent organic group, B is a C5 to C10 monovalent hydrocarbon group, C is a hydrolyzable group and/or a hydroxyl group, R.sup.1 is a C1 to C4 monovalent hydrocarbon group, and for a, b, c and d, 0<2a<1, 0<b<1, 0<c<3, 0d<2, and 0<2a+b+c+d<4.)

Claims

1. An organopolysiloxane of average compositional formula (1) below which contains a sulfide group-containing organic group and has a sulfide equivalent weight of not more than 1,000 g/mol
(A).sub.a(B).sub.b(C).sub.c(R.sup.1).sub.dSiO.sub.(4-2a-b-c-d)/2 (1) wherein A is a sulfide group-containing divalent organic group, B is a monovalent hydrocarbon group of 5 to 10 carbon atoms, C is a hydrolyzable group and/or a hydroxyl group, R.sup.1 is a monovalent hydrocarbon group of 1 to 4 carbon atoms, and the subscripts a, b, c and d satisfy the conditions 0<2a<1, 0<b<1, 0<c<3, 0d<2 and 0<2a+b+c+d<4.

2. The organopolysiloxane of claim 1, wherein the sulfide group-containing divalent organic group A has formula (2) below
*(CH.sub.2).sub.nS.sub.x(CH.sub.2).sub.n* (2) wherein n is an integer from 1 to 10, x is a statistical average value from 1 to 6, and * and * represent bonding sites; and the hydrolyzable group and/or hydroxyl group C has formula (3) below
*OR.sup.2 (3) wherein R.sup.2 is an alkyl group of 1 to 20 carbon atoms, an aryl group of 6 to 10 carbon atoms, an aralkyl group of 7 to 10 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, or a hydrogen atom, and * represents a bonding site.

3. The organopolysiloxane of claim 1 or 2, wherein B in average compositional formula (1) is a monovalent hydrocarbon group of 8 to 10 carbon atoms.

4. The organopolysiloxane of claim 1, wherein the sulfide equivalent weight is from 500 to 800 g/mol.

5. An organopolysiloxane comprising a co-hydrolytic condensation product of: 20 to 95 mol % of an organosilicon compound of general formula (4) below ##STR00007## wherein n is an integer from 1 to 10, x is a statistical average value from 1 to 6, R.sup.3 is an alkyl group of 1 to 20 carbon atoms, an aryl group of 6 to 10 carbon atoms, an aralkyl group of 7 to 10 carbon atoms or an alkenyl group of 2 to 10 carbon atoms, R.sup.4 is an alkyl group of 1 to 10 carbon atoms or an aryl group of 6 to 10 carbon atoms, and y is an integer from 1 to 3; 5 to 80 mol % of an organosilicon compound of general foiinula (5) below ##STR00008## wherein R.sup.3, R.sup.4 and y are as defined above, and p is an integer from 5 to 10; and 0 to 10 mol % of an organosilicon compound of general formula (6) below ##STR00009## wherein R.sup.3, R.sup.4 and y are as defined above, and q is an integer from 1 to 4.

6. A rubber compounding ingredient comprising the organopolysiloxane of claim 1.

7. The rubber compounding ingredient of claim 6, further comprising at least one type of powder, wherein the weight ratio of the organopolysiloxane (A) to the at least one type of powder (B), expressed as (A)/(B), is from 70/30 to 5/95.

8. A rubber composition comprising the rubber compounding ingredient of claim 6 or 7.

9. A tire formed using the rubber composition of claim 8.

Description

EXAMPLES

[0073] The invention is illustrated more fully below by way of Working Examples and Comparative Examples, although these Examples are not intended to limit the invention. In the following Examples, parts are given by weight, Et stands for an ethyl group, and elemental analysis was carried out by measurement with a Mod-1106 analyzer from CARLO ERBA. The viscosities are values measured at 25 C. using a capillary-type kinematic viscometer.

Working Example 1

[0074] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 161.7 g (0.3 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 165.9 g (0.6 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 16.2 g of 0.5 N aqueous hydrochloric acid (water, 0.9 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 7.8 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 80 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 14.7 wt %, a sulfide equivalent weight of 870 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 1.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.25(C.sub.8H.sub.17).sub.0.50(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Working Example 2

[0075] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 161.7 g (0.3 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 138.3 g (0.5 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 14.9 g of 0.5 N aqueous hydrochloric acid (water, 0.83 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 7.2 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 220 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 16.1 wt %, a sulfide equivalent weight of 796 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 2.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.27(C.sub.8H.sub.17).sub.0.45(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Working Example 3

[0076] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 161.7 g (0.3 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 110.6 g (0.4 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 13.5 g of 0.5 N aqueous hydrochloric acid (water, 0.75 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 6.5 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 800 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 17.8 wt %, a sulfide equivalent weight of 723 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 3.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.30(C.sub.8H.sub.17).sub.0.40(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Working Example 4

[0077] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 161.7 g (0.3 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 83.0 g (0.3 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 12.2 g of 0.5 N aqueous hydrochloric acid (water, 0.68 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 5.9 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 2,000 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 19.8 wt %, a sulfide equivalent weight of 649 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 4.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.33(C.sub.8H.sub.17).sub.0.33(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Working Example 5

[0078] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 210.2 g (0.39 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 83.0 g (0.3 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 13.0 g of 0.5 N aqueous hydrochloric acid (water, 0.72 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 6.3 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 70 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 20.9 wt %, a sulfide equivalent weight of 615 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 5.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.36(C.sub.8H.sub.17).sub.0.28(OC.sub.2H.sub.5).sub.1.67SiO.sub.0.67

Working Example 6

[0079] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 231.8 g (0.43 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 83.0 g (0.3 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 13.9 g of 0.5 N aqueous hydrochloric acid (water, 0.77 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 6.7 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 220 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 21.4 wt %, a sulfide equivalent weight of 599 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 6.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.37(C.sub.8H.sub.17).sub.0.26(OC.sub.2H.sub.5).sub.1.67SiO.sub.0.67

Working Example 7

[0080] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 247.9 g (0.46 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 83.0 g (0.3 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 14.6 g of 0.5 N aqueous hydrochloric acid (water, 0.81 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 7.0 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 2,600 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 21.8 wt %, a sulfide equivalent weight of 589 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 7.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.38(C.sub.8H.sub.17).sub.0.25(OC.sub.2H.sub.5).sub.1.67SiO.sub.0.67

Comparative Example 1

[0081] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 107.8 g (0.2 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 276.5 g (1.0 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 18.9 g of 0.5 N aqueous hydrochloric acid (water, 1.05 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 9.1 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 10 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 8.4 wt %, a sulfide equivalent weight of 1.533 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 8.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.14(C.sub.8H.sub.17).sub.0.71(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Comparative Example 2

[0082] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 107.8 g (0.2 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 221.2 g (0.8 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 16.2 g of 0.5 N aqueous hydrochloric acid (water, 0.9 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 7.8 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 20 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 9.8 wt %, a sulfide equivalent weight of 1.312 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 9.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.17(C.sub.8H.sub.17).sub.0.67(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Comparative Example 3

[0083] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 107.8 g (0.2 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 165.9 g (0.6 mol) of octyltriethoxysilane (KBE-3083, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 13.5 g of 0.5 N aqueous hydrochloric acid (water, 0.75 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 6.5 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 35 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 11.8 wt %, a sulfide equivalent weight of 1,091 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 10.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.20(C.sub.8H.sub.17).sub.0.60(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Comparative Example 4

[0084] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 161.7 g (0.3 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 61.9 g (0.3 mol) of propyltriethoxysilane (KBE-3033, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 12.2 g of 0.5 N aqueous hydrochloric acid (water, 0.68 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 5.9 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 350 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 22.2 wt %, a sulfide equivalent weight of 579 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 11.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.33(C.sub.8H.sub.17).sub.0.33(OC.sub.2H.sub.5).sub.1.50SiO.sub.0.75

Comparative Example 5

[0085] A one-liter separable flask equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer was charged with 247.9 g (0.46 mol) of bis(triethoxysilylpropyl)tetrasulfide (KBE-846, from Shin-Etsu Chemical Co., Ltd.), 61.9 g (0.3 mol) of propyltriethoxysilane (KBE-3033, from Shin-Etsu Chemical Co., Ltd.) and 162.0 g of ethanol, following which 14.6 g of 0.5 N aqueous hydrochloric acid (water, 0.81 mol) was added dropwise at room temperature. The flask contents were then stirred for 2 hours at 80 C., after which filtration was carried out, followed by the dropwise addition of 7.0 g of a 5 wt % KOH/EtOH solution and 2 hours of stirring at 80 C. Vacuum concentration and filtration afforded a clear brown liquid having a viscosity of 800 mm.sup.2/s. Elemental analysis was carried out, whereupon the resulting silicone oligomer was found to have a sulfur content of 23.6 wt %, a sulfide equivalent weight of 543 g/mol and the average compositional formula shown below. This oligomer was called Oligomer 12.

(C.sub.3H.sub.6S.sub.4C.sub.3H.sub.6).sub.0.38(C.sub.8H.sub.17).sub.0.25(OC.sub.2H.sub.5).sub.1.67SiO.sub.0.67

Working Examples 8 to 14, Comparative Examples 6 to 11

[0086] As shown in Tables 1 and 2, masterbatches were prepared by blending together 110 parts of oil-extended emulsion-polymerized SBR (#1712 from JSR Corporation), 20 parts of NR (common grade RSS 3), 20 parts of carbon black (common grade N234), 50 parts of silica (Nipsil AQ, from Nippon Silica Industries), 6.5 parts of the oligomers in Working Examples 1 to 7 and Comparative Examples 1 to 5 or Comparative Compound A shown below, 1 part of stearic acid, and 1 part of the antioxidant 6D (Ouchi Shinko Chemical Industrial Co., Ltd.). Next, 3 parts of zinc white, 0.5 part of the vulcanization accelerator DM (dibenzothiazyl disulfide), 1 part of the vulcanization accelerator NS (N-t-butyl-2-benzothiazolyl sulfenamide) and 1.5 parts of sulfur were added to the above blend and kneaded, giving a rubber composition.

Comparative Compound A

[0087]
(EtO).sub.3SiC.sub.3H.sub.6S.sub.4C.sub.3H.sub.6Si(OEt).sub.3 [Chemical Formula 7]

[0088] Next, the properties of the rubber compositions in the unvulcanized form and in the vulcanized form were measured by the following methods. The results are shown in Tables 1 and 2.

[Properties of Unvulcanized Composition]

(1) Mooney Viscosity

[0089] Measured in accordance with JIS K 6300 after allowing 1 minute for sample to reach thermal equilibrium with viscometer; measurement was carried out for 4 minutes at 130 C. The results are expressed as numbers relative to an arbitrary value of 100 for the result in Comparative Example 11. A smaller number indicates a lower Mooney viscosity and thus a better processability.

[Properties of Vulcanized Composition]

(2) Dynamic Viscoelasticity

[0090] Using a viscoelastic tester (Rheometrics), measurement was carried out at 5% dynamic strain under tension, a frequency of 15 Hz and 60 C. Using sheets having a thickness of 0.2 cm and a width of 0.5 cm as the test specimens, the clamping interval in the tester was set to 2 cm and the initial load was set to 160 g. The tan values are expressed as numbers relative to an arbitrary value of 100 for the result in Comparative Example 11. A smaller number indicates a smaller hysteresis loss and lower heat buildup.

(3) Wear Resistance

[0091] Testing was carried out in general accordance with JIS K 6264-2: 2005 using a Lambourn abrasion tester under the following conditions: room temperature, 25% slip ratio. The results are expressed as numbers relative to an arbitrary value of 100 for the reciprocal of the abrasion loss in Comparative Example 11. A larger number indicates a lower abrasion loss and excellent wear resistance.

TABLE-US-00001 TABLE 1 Working Example 8 9 10 11 12 13 14 Recipe (pbw) SBR 110 110 110 110 110 110 110 NR 20 20 20 20 20 20 20 Carbon black 20 20 20 20 20 20 20 Silica 50 50 50 50 50 50 50 Stearic acid 1 1 1 1 1 1 1 Antioxidant 6C 1 1 1 1 1 1 1 Zinc white 3 3 3 3 3 3 3 Vulcanizing 0.5 0.5 0.5 0.5 0.5 0.5 0.5 accelerator DM Vulcanizing 1 1 1 1 1 1 1 accelerator NS Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Oligomer 1 6.5 Oligomer 2 6.5 Oligomer 3 6.5 Oligomer 4 6.5 Oligomer 5 6.5 Oligomer 6 6.5 Oligomer 7 6.5 [Properties of Unvulcanized Composition] Mooney viscosity 99 98 96 99 98 99 98 [Properties of Vulcanized Composition] Dynamic viscoelasticity, 95 92 90 88 87 86 85 tan (60 C.) Wear resistance 105 105 106 108 110 110 112

TABLE-US-00002 TABLE 2 Comparative Example 6 7 8 9 10 11 Recipe (pbw) SBR 110 110 110 110 110 110 NR 20 20 20 20 20 20 Carbon black 20 20 20 20 20 20 Silica 50 50 50 50 50 50 Stearic acid I I 1 1 1 1 Antioxidant 6C I I 1 1 1 1 Zinc white 3 3 3 3 3 3 Vulcanizing accelerator DM 0.5 0.5 0.5 0.5 0.5 0.5 Vulcanizing accelerator NS 1 1 1 1 1 1 Sulfur 1.5 1.5 1.5 1.5 1.5 1.5 Oligomer 8 6.5 Oligomer 9 6.5 Oligomer 10 6.5 Oligomer 11 6.5 Oligomer 12 6.5 Comparative Compound A 6.5 [Properties of Unvulcanized Composition] Mooney viscosity 98 99 97 98 95 100 [Properties of Vulcanized Composition] Dynamic viscoelasticity, 112 110 108 102 102 100 tan (60 C.) Wear resistance 83 85 88 92 92 100