公开(公告)号：JPH04121202A

公开(公告)日：1992-04-22

申请号：JP24064490

申请日：1990-09-11

Applicant: BRIDGESTONE CORP

Inventor： YAMAMOTO HISAO

IPC: B60C9/18 ,  B60C9/20 ,  B60C9/22

Abstract: PURPOSE:To prevent separation of a belt and improve durability of the edge portion of the belt by composing the belt of a belt trunk layer in which two kinds of wide and narrow, metallic cords are buried adjacently and crosswise, and respectively specifying a ratio of hardness between coating rubbers of both belt layers and an elongation of the wide belt layer when its coating rubber is broken. CONSTITUTION:A belt truck layer 4 is composed of a truck layer 4A consisting of four layers 41 to 44 located inside in the radial direction of a tire. A belt trunk layer 42 defined as a belt layer P which forms a free end is sandwiched by belt layers 41Q and 43Q from inside and outside. An elongation of the belt truck layer 42 is set to be 300 percent or more when the coating rubber is broken. Further, when JIS spring type hardness (A type) of coating rubber of the belt layer 42 is assigned to HA, and the same hardness of the belt layers 41 and 43 is assigned to HB, a ratio of both hardness HB/HA is set to be 1.0

公开(公告)号：JPH04100705A

公开(公告)日：1992-04-02

申请号：JP21755490

申请日：1990-08-18

Applicant: BRIDGESTONE CORP

Inventor： YAMAMOTO HISAO

IPC: B60C9/18 ,  B60C9/20

Abstract: PURPOSE:To obtain a pneumatic radial tire for wasteland traveling use by arranging large-diameter cords and a high-hardness covering rubber to the main layer, and small-diameter cords and a low-hardness covering rubber to the protective layer respectively, and by determining these hardnesses of rubber and the diameters of the cords so as to satisfy a specific expression. CONSTITUTION:A tire 1 comprises a carcass 2 and a main belt layer 4 for hooping the crown part 3, and is made up of a plurality of layers in which cords 6 for reinforcing a belt layer A are arranged so as to be crossed each other with the equator between, and a protective layer 5 of the main belt layer 4 on the radially outside of the tire is made up of a plurality of layers in which cords 7 for reinforcing a belt layer B are arranged so as to be crossed each other with the equator between. The cord diameter phiA of the cord 6 is determined to be larger than the cord diameter phiB of the cord 7, and the cords 6 and 7 are embedded in covering rubbers 8, 9 having JIS spring type hardnesses HA, HB respectively. And, the cord diameters phiA, phiB and covering rubber hardnesses HA, HB are determined to satisfy the expression 1.0 .

公开(公告)号：JPS63314252A

公开(公告)日：1988-12-22

申请号：JP15031587

申请日：1987-06-18

Applicant: BRIDGESTONE CORP

Inventor： YAMAMOTO HISAO ,  SAITO TADASHI

IPC: B60C11/00 ,  B60C1/00 ,  C08K3/04 ,  C08K5/34 ,  C08L7/00 ,  C08L9/00

Abstract: PURPOSE:To obtain the title tire improved in abrasion resistance on a good road and improved also in partial abrasion resistance, by mixing a stock rubber with a specified carbon black, a specified bismaleimide compound and sulfur each in a specified range of amount and specifying the resiliency in a specified range. CONSTITUTION:The title tire wherein tread rubber comprises a rubber composition prepared by mixing 100pts.wt. stock rubber comprising 50-100pts.wt. natural rubber or natural rubber/isobutyrene mixture and 50-0pt.wt. styrene/ butadiene rubber and/or butadiene rubber with 0.5-3pts.wt. bismaleimide compound (A) of the formula (wherein R is a 2-6C alkylene, phenylene, naphthylene or tolylene), 0.5-2pts.wt. sulfur (B) and 40-60pts.wt. carbon black (C) of a nitrogen adsorption specific surface area (N2SA) of 110-150m /g and a compressed dibutyl phthalate absorption (DBP value) of 100-130ml/100g, and the resiliency of a sample of the tread rubber sampled from a vulcanized tire is 48-57%. This tire is improved in abrasion resistance in running on a good road and partial abrasion resistance.

公开(公告)号：JPS63312333A

公开(公告)日：1988-12-20

申请号：JP14973687

申请日：1987-06-15

Applicant: BRIDGESTONE CORP

Inventor： ITO MICHIO ,  YAMAMOTO HISAO ,  OKAMURA NOBUYUKI ,  MORITA KOICHI

IPC: C08K5/34 ,  C08L7/00 ,  C08L21/00

Abstract: PURPOSE:To obtain the titled composition giving a tire or belt, etc., having excellent heat-resistance and adhesivity to cord and high elastic modulus, by compounding a specific toluenebismaleimide and sulfur to a base rubber. CONSTITUTION:100pts.wt. of a rubber composed of natural rubber and/or synthetic rubber is compounded with 0.5-10pts.wt. of N,N'-toluenebismaleimide and 0.2-6pts.wt. of sulfur. The N,N'-toluenebismaleimide is preferably a mixture of N,N'-2,4-toluenebismaleimide and N,N'-2,6-toluenebismaleimide at a ratio of 80:20.

公开(公告)号：JPH06328912A

公开(公告)日：1994-11-29

申请号：JP14542093

申请日：1993-05-26

Applicant: BRIDGESTONE CORP

Inventor： NAGAI YUICHI ,  YAMAMOTO HISAO

IPC: B60C1/00 ,  B60C13/00

Abstract: PURPOSE:To improve resistance against a side cutting property without reducing various performance of a tire by specifying the predetermined performance and relative relation of inner and outer layers of a side wall having two-layer rubber structure. CONSTITUTION:A side wall which covers both sides of a tire 1 has two-layer rubber structure consisting of an outer layer 2 and an inner layer 3. Rubber of the outer layer 2 is made by blending syndiotactic-1, 2-polybutadiene whose melting point is 80 to 160 deg.C of 3 to 30 weight parts with diene system rubber of 1000 weight parts. Also, when HA represents hardness of the outer layer rubber 2 and Hg represents hardness of the inner layer rubber 3, it is selected in such a way that the relation of 1

公开(公告)号：JPH03174458A

公开(公告)日：1991-07-29

申请号：JP31340089

申请日：1989-12-04

Applicant: BRIDGESTONE CORP

Inventor： YAMAMOTO HISAO

IPC: B60C1/00 ,  C08L9/00 ,  C08L21/00

Abstract: PURPOSE:To improve the workability in producing a tire and increase the durability of the tire by using a member obtd. by molding a compsn. comprising a rubber component (mainly comprising a diene rubber) and a hydrogenated polyisoprene as an adjacent member to a member obtd. by molding a specific rubber compsn. CONSTITUTION:100 pts.wt. rubber component contg. 60wt.% or higher diene rubber is compounded with 2-30 pts.wt. hydrogenated polyisoprene which has a viscosity average mol.wt. of 5000-100000 and in which 60-98% of C-C double bonds in the polymer molecule are hydrogenated. The resulting rubber compsn. is molded into a member of a tire. The member is used as an adjacent member to a member (e.g. a ply-coating rubber and inner side-lining rubber) obtd. by molding a compsn. contg. a rubber component comprising a nondiene rubber and, if necessary, a diene rubber.

公开(公告)号：JPH01168739A

公开(公告)日：1989-07-04

申请号：JP32889687

申请日：1987-12-25

Applicant: BRIDGESTONE CORP

Inventor： YAMAMOTO HISAO ,  ITO MICHIO ,  WATANABE YOICHI ,  ISEDA YUTAKA ,  KINOSHITA TAKESHI

IPC: C08K5/13 ,  C08K5/00 ,  C08K5/34 ,  C08K5/56 ,  C08L7/00 ,  C08L9/00

Abstract: PURPOSE:To obtain a rubber composition which can give a tire simultaneously improved in both durability and productivity, by adding a phenoxy cobalt salt and a bismaleimide compound to a natural rubber or a synthetic polyisoprene rubber. CONSTITUTION:This rubber composition is prepared by adding 0.01-1 pt.wt. (in terms of a cobalt element content) phenoxy cobalt salt of formula I or II and 0.2-10 pts.wt. bismaleimide compound of formula III to 100 pts.wt. rubber component containing at least 70 pts.wt. natural rubber and/or synthetic rubber. In the formulas, R1-R11 are each H, a hydroxyl group, a 1-18 C alkyl, a 5-12C cycloalkyl, a 1-16C alkylthio group, a 6-14C aryl, a sulfur atom, a dithio group, O, a 1-4C alkyl-N group or the like, and Z is a 2-10C hydrocarbon group. Said rubbers which constitute the rubber composition are sulfur- vulcanizable rubbers, and among them, a natural rubber, a polyisoprene rubber, a polybutadiene rubber, a styrene/butadiene copolymer rubber or a blend thereof is particularly desirable because of their wide versatility.