A web product having a machine direction and a cross-machine direction orthogonal thereto is disclosed. The web product has at least one ply having a first plurality of pillow regions having a first total area in the machine and cross-machine directions and a second plurality of pillow regions having a second total area in the machine and cross-machine directions where the first and second total areas have a different value. The web product has a Dry Bulk, DB, value greater than 15.5 cc/g and a Total Tensile Strength, TT, value greater than 2000 g/25.4 mm.

The invention provides methods and compositions for improving the characteristics of paper substrates. The method involves adding to a paper substrate an NCC-polymer. NCC-polymers have unique chemical properties which result in improvements in wet strength, dry strength and drainage retention properties of the paper substrates.

Disclosed are methods for increasing the filler content of paper or paperboard, comprising (a) combining a heterogeneous polymer blend with a ground calcium carbonate filler; (b) combining the resulting mixture with a pulp slurry; and (c) processing the resulting slurry mixture to form a sheet of paper or paperboard. Also disclosed are methods of increasing the filler content of paper or paperboard comprising (1) combining either a heterogeneous polymer blend or a ground calcium carbonate filler with a pulp slurry, (2) combining the remaining component with the pulp slurry; and (c) processing the resulting pulp slurry mixture to form a sheet of paper or paperboard.

A sheet manufacturing apparatus includes a defibrating unit configured to defibrate a defibration object including at least a fiber, in air. The sheet manufacturing apparatus forms a sheet by adding quantity of heat to a defibrated material defibrated at the defibrating unit. The sheet manufacturing apparatus includes a measuring unit configured to acquire moisture amount information of the defibrated material or the defibration object, and a controller configured to control the quantity of heat to be added to the defibrated material on the basis of the moisture amount information.

Compositions and methods related to new wet strength resins are provided. By using functionally-symmetrical cross-linkers and mono-functional modifiers, and separating the steps of reacting a prepolymer with the cross-linkers from the reaction of intermediate cross-linked prepolymer with epichlorohydrin, new wet strength resin products are provided having improved properties.

The invention relates to a method for precipitating calcium carbonate, in which method calcium hydroxide is introduced to a fiber suspension containing cellulose-containing fibers, the calcium hydroxide is allowed to attach onto the surfaces of fibers for a pre-determined time, and the aqueous suspension of calcium hydroxide and fibers is brought into contact with carbon dioxide for precipitating the calcium carbonate. The invention also relates to a corresponding system for precipitating calcium carbonate in connection with cellulose-containing fibers. In addition, the invention relates to a fibrous product, which comprises pulp material produced by said method and comprising calcium carbonate.

A pneumatic tire for improving steering stability performance on dry and wet road surfaces. The tire tread pattern has circumferential center main grooves, outside and inside main grooves, land sections demarcated by the main grooves, ground contact borders on both sides of the tire, and closed shoulder lug grooves. A ratio Wmax/Wout of a maximum main groove width Wmax and an outside main groove width Wout is at between 1.5 and 2.5 inclusive. A ratio Sin/Sout of a groove area ratio Sin of a region on a tire-widthwise second side of a tire centerline and a groove area ratio Sout of a region on a first side of the tire centerline is at least 1.10 and smaller than 1.25. A groove area ratio of a region on the second side of a tire-widthwise centerline of the intermediate land sections exceeds that of a region on the first side.

A non-pneumatic tire for supporting a load by working in tension comprising a generally annular inner surface, a generally annular outer ring, and an interconnected web having a plurality of web elements and comprising a plurality of generally polygonal openings. Web elements are sized, oriented and comprised of a material that facilitates buckling when subjected to a compressive load. By buckling, those elements in a deformed portion of the tire between a hub and a footprint region where the tire contacts a surface may assume a significantly reduced portion of the load, if any. This causes web elements in other portions of the interconnected web to operate in tension to support the load. With the portion of the tire in the footprint region not bearing a significant portion of the load, non-pneumatic tire may exhibit a more comfortable ride subject to less noise and vibration and improved handling capabilities.

A pneumatic tire in which an inner liner including a film mainly made of thermoplastic resin is attached to an inside of the tire via a tie rubber sheet, on an inner side of a carcass layer, and which has a lap-splice portion where end portions of the film in a tire circumferential direction overlap each other in a tire widthwise direction with tie rubber therebetween. A section of the film on a tire cavity side in the lap-splice portion has a portion where the film is thin over part or entirety of the width in the tire widthwise direction before the lap-splice portion, or a film thickness in the lap-splice portion is smaller than a film thickness in a portion other than the lap-splice portion. Thus, the pneumatic tire has no crack developing around the lap-splice portion of an inner liner layer after running, and has excellent durability.

It is a problem to provide a pneumatic tire where disengagement between sipe wall surfaces is suppressed. In a sipe formed in a block of a tread portion, two ridge portions (32) and (34) are formed in one sipe wall surface (29P), and two valley portions that engage with the ridge portions (32) and (34) are formed in another sipe wall surface. The two ridge portions (32) and (34) form a merged portion (30) where they merge together in the center of a sipe lengthwise direction and at their tire radial direction outside ends, and the two ridge portions (32) and (34) extend linearly from the merged portion (30) toward both sipe-lengthwise-direction end sides (F) and (K) so as to gradually move apart inward in the tire radial direction. Because of this configuration, the contact length of the adjacent sipe wall surfaces in a sipe depth direction (R) becomes longer.

In a pneumatic tire, center land portions include a circumferential narrow groove extending in the tire circumferential direction so as to partition the center land portions in a tire width direction; a plurality of lug grooves disposed in each region of each of the center land portions partitioned by the circumferential narrow groove, extending in the tire width direction, so as to partition each of the regions of the center land portions in the tire circumferential direction; and a plurality of blocks partitioned by the circumferential narrow groove and the plurality of lug grooves. Blocks of the center land portions include one open sipe extending in the tire width direction so as to partition the blocks in the tire circumferential direction, and three or more closed sipes disposed in each of the regions of each of the blocks partitioned by the open sipe.

A pneumatic radial tire in which a plurality of land portion rows 2 are formed by a plurality of main grooves that extend in the circumferential direction on a tread portion of a tire, and a thin groove 3 that extends in the tire circumferential direction is formed in at least one shoulder land portion row 2A that is positioned on the tread end among the plurality of land portion rows. A land portion 5 that is positioned between, the thin groove 3 and the tread end 4 is partitioned into a plurality of blocks 5a by a lug groove 6 that extends in the tire width direction and whose maximum groove depth is set deeper than the groove depth of the thin groove, and the groove depth of the lug groove continuously changes so as to become a maximum at an intermediate position between the thin groove and the tread end. According to the present invention, it is possible to provide a pneumatic radial tire that can achieve improved drainage performance.

Tyre and rubber composition for tyre, based on at least one isoprene elastomer (for example natural rubber), an inorganic filler as reinforcing filler (for example silica) and a coupling system which provides the bonding between the said reinforcing inorganic filler and the isoprene elastomer, the said coupling system comprising, in combination: as first coupling agent, a silane sulphide compound;as second coupling agent, an at least bifunctional organosilicon compound (for example an organosilane or an organosiloxane) which can be grafted to the elastomer by means of an azodicarbonyl functional group (—CO—N═N—CO—).

A method for locking a tire to a wheel rim, includes the steps of mounting a tubular tire locking element on the wheel rim, which tubular locking member is arranged with a valve, which valve is pushed through a hole in the rim; mounting a tire on the rim such that the tire encloses the tubular tire locking element and a pressure chamber is obtained between the tire locking element and the tire; pressurizing the tubular tire locking element via the valve such that it expands, whereby the beads of the tire are pressed against the flanges of the wheel rim; inserting a hollow needle through the tire and into the pressure chamber, which hollow needle is connected to a pressurized air source; pressurizing the pressure chamber to desired pressure, removing the hollow needle; and sealing the hole caused by the needle with sealing fluid or plug.

A non-pneumatic tire includes a plurality of springs. Each spring includes a first end portion, a second end portion, and an arching middle portion. Each spring is interwoven with at least one other spring thereby forming a toroidal structure extending about an entire circumference of the non-pneumatic tire. The toroidal structure is at least partially coated with an elastomer. One end portion of at least one spring is wrapped around a first bead structure adjacent a rim.

A pneumatic tire is provided with a main groove extending along a tire circumferential direction in a tread. A side wall of a land portion facing the main groove extends so as to be inclined with respect to a tire circumferential direction between a pair of corner portions. The corner portion positioned in an inner side in a width direction of the main groove is set to an inner corner portion and the corner portion positioned in an outer side is set to an outer corner portion. In the inner corner portion, the side wall is formed by a stepped surface expanding to the outer side in the width direction toward a groove bottom and an expansion to the outer side in the width direction in the stepped surface is made smaller from the inner corner portion toward the outer corner portion.

A pneumatic tire including at least four circumferential main grooves extending in the tire circumferential direction and a plurality of rib-like land portions partitioned by the circumferential main grooves in the tread portion. Additionally, an outer side second land portion includes a zigzag narrow groove having a zigzag shape, extending in the tire circumferential direction, and dividing the outer side second land portion in the tire width direction; and a plurality of first sipes disposed at a predetermined pitch in the tire circumferential direction, extending from an edge portion on the outer side in the tire width direction of the outer side second land portion toward the inner side in the tire width direction, and terminating prior to the zigzag narrow groove, leaving a gap for ventilation.

A pneumatic tire including a separatable pair of mechanical fasteners wherein a first fastener of the pair of mechanical fasteners is provided on a tire inner surface. In this pneumatic tire, the obtained engagement force of the pair of mechanical fasteners is great and is essentially free of variations (positional variation within the tire and variation from tire to tire); the engagement force deteriorates/declines minimally over time due to extreme usage conditions including repetitive deformation and compaction over an extended period of time caused by tire rotation at high speeds in a state of relatively elevated temperatures; and the desired engagement force can be maintained over an extended period of time.

The present invention includes a run-flat tire 1 comprising a plurality of turbulence generation ridges 20 which extend on a surface of a tire side portion 3 in a tire-radial direction and which are arranged at a pitch in a tire-circumferential direction and relationship Si>So is satisfied. Si is the sum of sidewall areas of all the turbulence generation ridges located at the inner side, in the tire-radial direction, of a maximum width position of the pneumatic tire. So is the sum of sidewall areas of all the turbulence generation ridges located at the outer side, in the tire-radial direction, of the tire maximum width position.

Bicycle tires with at least one reinforcement layer that contains strength supports and that is arranged between carcass and tread rubber and/or between carcass layers below the tread rubber and/or within the tread rubber. For a high resistance to puncturing with low weight, the reinforcement layer contains multifilament threads of more than 30 polyester/polyarylate filaments, and the filaments are spun from molten liquid-crystal polymer.

A belt structure for a two-wheeled vehicle made by means of strip-like segments or elements, each including parallel cords embedded in an elastomeric layer, sequentially laid along the circumferential extension of a toroidal support so as to form a reinforcing layer having a continuous circumferential extension around a geometric rotation axis of the toroidal support, wherein each strip-like element is laid in a laying trajectory defining, at each point, a laying angle; at each point of the laying trajectory a laying gap is formed between adjacent strip-like elements; the laying trajectory is formed starting from preselected laying angles on the shoulder and on the crown of the tire; the laying gap between adjacent strip-like elements varies along at least one length of said laying trajectory between crown and shoulder so as to cause variation of the laying angle and obtain the preselected angles on the shoulder and on the crown.

Particular embodiments of the present invention include a multi-stage tire tread having a plurality of wear layers, each said layer being located at a different depth of the tire tread, the tread including one or more tread elements including a contact surface and having a first wear layer and a second wear layer, wherein the second wear layer is located below the first wear layer. The tire tread also includes a longitudinal groove extending in a longitudinal direction within the second wear layer of the tread element, wherein said longitudinal groove becomes exposed after a depth of the first wear layer has been worn. The tire tread further includes one or more lateral grooves extending from the longitudinal groove in a lateral direction within the second wear layer of the tread element. The invention also provides a mold element for forming portions of the multi-stage tread.

A tire having a tread includes an outer tread layer and an inner tread layer. The inner tread layer includes one of a first elastomeric compound and a second elastomeric compound. The outer tread layer includes the other of the first and second elastomeric compounds. The second elastomeric compound has a lower rolling resistance and greater resistance to treadwear than the first elastomeric compound. The inner tread layer increases in thickness across at least a widthwise portion of the outer tread layer with a maximum thickness of one of the inner tread layer and the outer tread layer occurring near at least one of a first shoulder and a second shoulder of the tread. As the tread wears, the inner tread layer defines a greater proportion of a running surface of the tread.

A tire (10) for driving on ice, comprising: a tread (20) having a rolling surface configured to come into contact with the ground when the tire is rolling along, and two lateral faces (27), this tread comprising at least one groove (25, 26) in the rolling surface; at least one stud (30) having a longitudinal axis (33), a part (31) of the stud projecting from the rolling surface, the intersection between the stud and the plane tangential to the portion of the rolling surface around the stud forming a contour C, that part of the stud that projects from the rolling surface having a minimum cross section Sm, Sm corresponding to the smallest cross section of the said part in any plane containing the radial direction that passes through the point of intersection between the longitudinal axis of the stud and the plane tangential to the portion of the rolling surface around the stud; at least one conduit (200-205) that forms, on the rolling surface of the tire, at least two opposing edges (211, 221; 212, 222; 213, 223), the minimum distance D between the conduit and the contour C being less than or equal to 1 cm, the conduit opening into the groove and/or onto a lateral face of the tread; wherein, for each stud, the sum of the mean cross sections Sn of the conduits, each mean cross section Sn being measured at right angles to one of the opposing edges formed by the conduit, is greater than or equal to half the minimum cross section Sm of that part of the stud that projects from the tread.

A pneumatic tire that is provided with a first fastener of a separatable pair of mechanical fasteners on a tire inner surface, wherein, even in cases where a desired object is engaged/fixed using only one fastener, the object does not rotate having the fastener as a central axis when the tire is in use. A first fastener of the pair of mechanical fasteners is provided on a tire inner surface, and the mechanical fasteners are provided with a rotation preventing mechanism for preventing the fasteners from mutually rotating when the pair of mechanical fasteners are engaged.

A rubber composition for tire treads is obtained by blending, per 100 parts by mass of a diene rubber, 5 to 150 parts by mass of silica and 0.5 to 20 parts by mass of a silicone oligomer represented by the following siloxane average formula (1): (X)a(Y)b(R1)c(R2)dSiO(4-a-b-c-d)/2 (wherein X is a mercapto group-containing organic group; Y is a hydrolyzable group, R1 is a monovalent hydrocarbon group having from 4 to 10 carbon atoms, R2 is a monovalent hydrocarbon group having from 1 to 3 carbon atoms, 0

The present invention provides a rubber composition that improves in terms of the fuel economy of a rubber composition containing an isoprene-based rubber and also offers favorable durability and favorable processability or adhesion to steel cords, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for a bead apex, sidewall packing, base tread, or breaker cushion, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of sulfur; and a specific amount of a compound represented by formula (I) below. The present invention also relates to a rubber composition for a steel cord topping, strip adjacent to steel cords, or tie gum, including: a specific rubber component; a specific amount of a specific carbon black; a specific amount of an organic acid cobalt salt; and a specific amount of a compound represented by the formula (I).

Provided is a pneumatic tire whose braking performance on ice and partial-wear resistance can be improved. Sipes 11X provided in a rib 5 on a tire equatorial plane TE are formed in such a three-dimensional shape that the amount at which the rib 5 collapses due to an external force is smaller in the tire rotational direction than in a direction opposite to the tire rotational direction. In each block 10 in each shoulder region 1S, sipes 11Ma in a block tread-in side portion 10A are each formed in such a three-dimensional shape that the amount at which the block 10, if entirely provided with the sipes 11Ma, collapses due to an external force will be smaller in the tire rotational direction than in the direction opposite to the tire rotational direction. Sipes 11Mb in a block kick-out side portion 10B are each formed in such a three-dimensional shape that the amount at which the block 10, if entirely provided with the sipes 11Mb, collapses due to an external force will be smaller in the direction opposite to the tire rotational direction than in the tire rotational direction.

A heavy duty pneumatic tire comprises a tread portion provided with circumferentially continuous main grooves and lateral grooves to form blocks in circumferential rows. The main grooves include a pair of shoulder main grooves disposed one on each side of the tire equator so that the center line thereof is at a distance of 0.30 to 0.65 times one half of the tread width from the tire equator. The blocks include crown blocks disposed in a tread crown region between the shoulder main grooves, and shoulder blocks disposed in shoulder regions axially outside the shoulder main grooves. Each of the crown blocks and shoulder blocks is provided with at least one axially extending sipe.

The present invention relates to a tire tread comprising a plurality of circumferential grooves separating circumferential ribs, each groove comprising a bottom and two sidewalls, and a plurality of laterally separated reinforcements, wherein one reinforcement is arranged adjacent each circumferential groove, and wherein each reinforcement extends from the radially inner surface of the tread in a radial direction at least to the bottom of an adjacent circumferential groove to form the bottom of that groove. Further, the invention relates to a tire comprising a tread in accordance with the present invention.

An object of the present invention is to provide a pneumatic tire of which rolling resistance is reduced without impairing wear resistance. Specifically, the pneumatic tire of the present invention comprises: a tread portion; a pair of side wall portions; a pair of bead portions; a carcass constituted of at least one carcass ply extending in a toroidal shape between bead cores in the respective bead portions; a belt disposed on the outer peripheral side of a crown region of the carcass and formed by at least one inclined belt layer made of cords extending to be inclined with respect to the equatorial plane of the tire; and a tread rubber disposed on the radially outer side of the belt, wherein a ratio of BD/BW satisfies the following formula: (0.062×tire aspect ratio−0.01)

A mounted assembly of a wheel and a tire. The tire inflation pressure is greater than 9 bar, and a relative deflection of the tire greater than 30%. The rim comprises a drop-center functionality and is of monobloc type. A carcass reinforcement includes a circumferential alignment of carcass reinforcement elements anchored in the beads by a stack of circumferentially oriented reinforcement elements, and by an anchoring rubber mix having an elasticity modulus of less than 30 MPa at 10% deformation.

An intermediate article of manufacture formed as a first stage bead area subassembly for a split ply pneumatic tire carcass is disclosed. The bead area subassembly has an annular bead core; a bead apex; a ply strip; and preferably a sidewall affixed to the ply strip. The subassembly is formed into a disk-shaped bead area monocomponent. The ply strip is wrapped about the bead core and the apex to form a ply turnup and both the ply strip and the ply turnup extend radially outwardly from the bead core. The bead area subassembly when formed into the disk-shaped bead area monocomponent is placed on an annular holder device. The combination of the bead area monocomponent on the holder device can be stacked for storage and latter assembly into a split ply carcass. Preferably, the ply turnup can be oriented extending inside or axially inward of the bead core on final assembly to form a split ply tire having axially inside turnups. In the preferred embodiment the ply strip is reinforced by radially extending ply cords.

A tire containing a pair of beads, at least one carcass ply extending from one bead to the other bead forming a pair of sidewall areas of the tire and a tread area of the tire, and at least one layer of a knit fabric in the sidewall area of the tire, where the knit fabric has a warp and weft direction and is a double cord stitch knit fabric. A method of making the fabric and tire are also disclosed.

In the invention, at least a tire outer circumferential side portion of a tread portion is formed of a non-conductive rubber layer. The non-conductive rubber layer is formed by winding and laminating a non-conductive rubber ribbon along a tire circumferential direction. A conductive layer is provided on an outer circumference of the non-conductive rubber ribbon, and the conductive layer continuously and spirally extends along the tire circumferential direction, and is exposed on a tread surface from a bottom surface of the non-conductive rubber layer toward a tire outer circumferential side. Accordingly, an electricity generated in a vehicle body is discharged to a road through the conductive layer. Since the conductive layer is scattered within the non-conductive rubber layer and exposure on the tread surface is preferably secured, it is possible to achieve an excellent conductivity.

The present invention provides an adhesive composition that may improve both adhesiveness to a film layer and adhesiveness to a rubber layer, and an adhesion method using the same, as well as a laminate and a tire. The adhesive composition according to the present invention includes a rubber component, at least 80 mass % of which rubber component is an epoxidized natural rubber.

A pneumatic tire in which: a carcass layer is laid between paired bead sections; a belt layer is buried, on the outer peripheral side of the carcass layer, in a tread section; and multiple main grooves extending in a tire circumferential direction are provided in the tread section. In the pneumatic tire, a maximum groove depth of each of the main grooves is 8.5 mm to 15.0 mm, a ratio α of a section height SH of an actual tire to a section height SHstd calculated from a tire size is set in a range of 0.97≦α≦0.99, a contact area ratio is 65% to 70% under a measurement condition where an air pressure is 200 kPa and a load is 50% of a load carrying ability with the air pressure of 200 kPa, and an average contact pressure P is 300 kPa to 400 kPa under the measurement condition. The tire achieves enhanced wet performance without increasing tire weight.

A pneumatic tire comprises an annular tread portion including a plurality of circumferentially extending main grooves comprising an innermost groove, an outermost groove, and at least one middle groove arranged between the innermost groove and the outermost groove. The outermost groove comprises an inner sidewall, an outer sidewall, a groove bottom, and a groove opening opposite to the groove bottom, wherein the outermost groove has an asymmetric cross section with respect to any straight line perpendicular to the groove opening, and wherein the outer sidewall of the outermost groove is tilted by more than 20° with respect to a straight line perpendicular to the groove opening.

A tire 1 comprises rib-shaped land portions 20 extending in a tire circumferential direction TC and has a circumferential groove 30 adjacent to the land portions 20 and extending in the tire circumferential direction TC. Tread contact surfaces 10 of the land portions 20 form smooth surfaces with no gap when a normal load is applied and the tread contact surfaces are in contact with a road surface. The circumferential groove 30 includes a shallow groove portion 40 extending in the tread-width direction TW, and a deep groove portion 50 adjacent to the shallow groove portion 40 in the tire circumferential direction and extending in the tread-width direction. A deep groove portion 50 is recessed more inwardly in a tire radial direction TR than the shallow groove portion 40 with a groove bottom 40c of the shallow groove portion 40 being an upper end of the deep groove portion 50.

A tire (10) having a tread (12) includes a plurality of laterally spaced, circumferentially extending continuous ribs (11) defining grooves (14). Each groove has oppositely facing sidewalls (20, 22) and a bottom surface (30). A first set of stone bumpers is provided with each stone bumper (18) projecting laterally from one of the sidewalls with an end (24) extending towards the other sidewall of the groove. A second set of stone bumpers is provided with each stone bumper (18') projecting from the other sidewall with an end (26) extending towards the one sidewall of the groove. Each stone bumper of the first and second sets of stone bumpers 1) is integral with the associated sidewall and with a portion of the bottom surface of the groove, and 2) includes a cutout (34) defining a surface that is spaced from and in opposing relation to the bottom surface of the groove.

This invention relates to a rubber composition including a polyisoprene rubber having a very high cis-1,4-bond content and having an excellent balance between dynamic properties and processability, and more particularly to a rubber composition comprising as a rubber component (A) a synthetic polyisoprene rubber having a cis-1,4-bond content of not less than 99.0%, a 3,4-bond content of not more than 0.5% and a Mooney viscosity ML1+4 (100° C.) of 20-110 and (B) a natural rubber.

A rubber-steel hybrid cord of the present invention is characteristically formed by twisting a plurality of sheath filaments or sheath strands around a core in which a periphery of and space surrounded by one or a plurality of core filaments or a core strand are coated or filled with a filler rubber (A) containing an adhesion promoter, thereby forming a multilayer-twist steel cord or a multi-twist steel cord, and coating an outer surface of the multilayer-twist steel cord or the multi-twist steel cord with a coating rubber (C). Further, an amount of an adhesion promoter contained in the coating rubber (C) is equal to or more than an amount of the adhesion promoter contained in the filler rubber (A).

A tire with a radial carcass reinforcement made up of at least one layer of metal reinforcing elements, the tire comprising a crown reinforcement itself capped radially with a tread, the tread being connected to two beads via two sidewalls. At least 70% of the metal reinforcing elements of at least one layer of the carcass reinforcement are non wrapped cables which, in what is known as the air-wicking test, display a flow rate of less than 2 cm3/min, and at least 10% of the metal reinforcing elements of the at least one layer of the carcass reinforcement are cables which, in what is known as the air-wicking test, display a flow rate of greater than 4 cm3/min.

Provided is a pneumatic tire whose safety factor and durability are improved without generating a problem of an increase in the weight of a tire and an increase in the inner surface cord protrusion failure. Provided is a pneumatic tire including one or more carcasses 2 extending toroidally between bead cores 1 embedded in a pair of bead portions 11 respectively. A polyester fiber cord whose total decitex as a twisted cord is 4300 to 5100 dtex, whose cord strength as a dip treated cord is 6.5 to 7.2 cN/dtex and whose cord elongation at a stress loading of 2 cN/dtex is 3.5 to 4.0% is used as a reinforcing cord of the carcass 2, and the tenacity of a treat which is the reinforcing cord covered with rubber per unit width is 2.9 to 3.2 kN/cm.

A pneumatic tire for a commercial vehicle with a tread, wherein at least the part of the tread which comes into contact with the road contains a sulphur-vulcanized rubber mixture. The sulphur-vulcanized rubber mixture contains 90 to 50 phr (parts by weight, based on 100 parts by weight, of all of the rubbers in the mixture) of natural rubber, 10 to 50 phr of at least one polybutadiene having a glass transition temperature Tg of −110 to −65° C. and 5 to 50 phr of at least one aliphatic and/or aromatic hydrocarbon resin having a softening point (ring and ball to ASTM E 28) of 0 to 150° C., and a mean molecular weight Mn of less than 2000 g/mol and a polydispersity D=Mw/Mn of 1 to 5.

A pneumatic tire includes first and second side members at first and second sides and a tread section between the first and second side members. The tread section has a tread pattern including a pair of main grooves extending linearly in a circumferential direction of the tire and a land section extending in the circumferential direction between the main grooves. The land section includes a sub groove extending in the circumferential direction without connecting to the main grooves, and a first sipe connecting between the sub groove and one of the main grooves. The sub groove includes a first groove section extending diagonally toward the first side at 0 to 30 degrees with respect to the circumferential direction and a second groove section connecting to the first groove section and extending diagonally toward the second side at 10 to 45 degrees with respect to the circumferential direction.

Side lug rows are provided at both side regions of a tread surface and are formed by a plurality of lugs defined by lug grooves opening to edges in the tread width direction, and a central block row aligned on the tire equator and formed by a plurality of blocks is disposed between positions at ¼ of the tread surface width from the tire equator. The tire has a directional tread pattern, with a designated rotation direction, formed by circumferential grooves and width direction grooves that define the blocks of the central block row and are narrow grooves with a narrower groove width than the lug grooves. The distance from the tire equator to the groove wall in each of the circumferential grooves defining the blocks is set to be larger at a leading edge of each block than at a trailing edge of each block.

The pneumatic tire 1 includes a belt layer 14 that includes a circumferential reinforcing layer 145 and a pair of cross belts 142, 143. Also, the pneumatic tire 1 includes at least three or more circumferential main grooves 21 to 23 in the tread portion having groove bottoms that are convex in the groove depth direction. Also, the curvature radius RA of the groove bottom of an arbitrary first circumferential main groove 21, 22 and the curvature radius RB of the groove bottom of an arbitrary second circumferential main groove 23 have the relationship RA

A pneumatic tire comprises a tread portion, at least two circumferentially and continuously extending longitudinal grooves being provided with the tread portion, a land portion divided between the longitudinal grooves, a plurality of lateral grooves being provided with the land portion, each lateral grooves with one end communicating with one of the longitudinal grooves and the other end extending toward a tire equator, the longitudinal groove with a groove wall to which lateral grooves are connected, in each section between lateral grooves adjacent to a circumferential direction of the tire, the groove wall having a protruded portion and a dent portion being formed the nearest side of the tire equator, the protruded portion inclined with respect to the circumferential direction of the tire so as to gradually reduce a width of the longitudinal groove toward at least one lateral groove.

A pneumatic tire unit comprises a front tire to be mounted on a leading side of a vehicle, and a rear tire to be mounted on a trailing side of the vehicle. A plurality of recesses is provided in at least one tire side portion of the front tire, and a plurality of protrusions is provided on at least one tire side portion of the rear tire. A negative pressure region that can be generated at a back surface side of the vehicle is reduced and, therefore, air resistance of the vehicle is reduced and fuel economy is enhanced.