The present invention is directed to a pneumatic tire having a tread comprising a vulcanizable rubber composition comprising, based on 100 parts by weight of elastomer (phr), up to 100 phr of a solution polymerized styrene-butadiene rubber; from 5 to 50 phr of a fatty acid monoester of formula 1 ##STR00001##
where R.sup.1 is selected from C1 to C8 linear or branched alkyl, C1 to C8 linear or branched alkenyl, and C2 to C6 linear or branched alkyl substituted with from one to five hydroxyl groups; R.sup.2 is C11 to C21 alkyl or C11 to C21 alkenyl; from 5 to 50 phr of a hydrocarbon resin having a Tg ranging from −40° C. to 20° C.; less than 10 phr of a petroleum-derived oil; and from 50 to 130 phr of silica. optionally, from about 1 to 50 phr carbon black.

Disclosed is a rubber composition which suppresses poor mixing or poor dispersion from occurring between an organic polymer material derived from natural rubber and an inorganic material such as silica and exhibits excellent viscoelastic properties, and a silane coupling agent composition used in the same. Also disclosed is a silane coupling agent composition comprising a silane compound represented by Formula (1):

##STR00001##

wherein each variable is as defined herein.

A heavy duty pneumatic tire 2 is provided. A shoulder land portion 30s is formed on a tread 4 of the tire 2. Holes 46 are provided in the shoulder land portion 30s. Each hole 46 is provided at a position at which the hole 46 is not in contact with a normal line of an inner surface of the tire passing through an end of a tread surface 22, and a depth D of the hole 46 is not larger than a depth G of the shoulder circumferential groove 28s. The hole 46 includes an opening-side portion 92 and a hole bottom-side portion 96 connected to the opening-side portion 92 and provided radially inward of the opening-side portion 92. A width of a boundary 98 between an outer hole bottom-side portion 96A and an inner hole bottom-side portion 96B in the hole bottom-side portion 96 is 1.5 to 2.5 times a width of a radially inner end portion of the opening-side portion 92.

Provided is a friction design method capable of estimating sliding friction generated between mutual sliding surfaces of two sliding members lubricated with lubricant with high precision. The friction design method sets a friction coefficient μ in a sliding surface model corresponding to mutual sliding surfaces of two sliding members (2 and 3) lubricated with lubricant (step S1), and, based on a correlation between the friction coefficient μ and an oil film parameter (Λ(Rk) or Λ(Rk+Rpk)) calculated using a core portion level difference (Rk) or a sum of the core portion level difference (Rk) and reduced peak height (Rpk) as a parameter representing surface roughness in the sliding surface model (step S2), sets a target value for surface roughness of the sliding surfaces required to be controlled as a product (steps S3 to S6).

In a tire having composite grooves provided on a shoulder land portion, dry performance and wet performance are improved. The tire includes a tread portion 2. The tread portion 2 includes a first shoulder land portion 13. The first shoulder land portion 13 has shoulder lateral grooves 15 and shoulder composite grooves 20. The shoulder lateral grooves 15 and the shoulder composite grooves 20 are each curved so as to be convex in a tire circumferential direction. Each shoulder composite groove 20 includes, in a cross section thereof, a sipe element 21 having a width not greater than 1.5 mm and extending from a tread surface of the first shoulder land portion 13 in a tire radial direction, and a groove element 22 connected to an inner side in the tire radial direction of the sipe element 21 and having a width greater than 1.5 mm.

A low friction coated article includes a first structure that has a first lubricated surface coated with a first polyelectrolyte coating. A second structure has a second lubricated surface with a second polyelectrolyte coating opposite the first lubricated surface. The first and second polyelectrolyte coatings include alternating layers of positively charged polyelectrolyte layers and negatively charged polyelectrolyte layers hydrated with a lubricant.

A first lateral groove and a second lateral groove are formed in a pneumatic tire. A first inclined portion is formed on one side of the first lateral groove in the tire circumferential direction, and a second inclined portion is formed on the other side of the second lateral groove in the tire circumferential direction. The first inclined portion is inclined from tire radial direction outside to tire radial direction inside by chamfering the end of one side circumferential block in the tire circumferential direction. The second inclined portion is inclined from tire radial direction outside to tire radial direction inside by chamfering the end of the other side circumferential block in the tire circumferential direction. The first inclined portion crosses the circumferential block and communicates with the circumferential groove. One end portion of the second inclined portion in the tire width direction terminates in the circumferential direction block.

In the tread of the tire, the average modulus value in a center region including the equatorial plane of the tire is higher than the average modulus value in shoulder regions adjacent to edges of the tread, and in the shoulder regions, the modulus value is higher in a surface layer of the tread than in a portion other than the surface layer.

A pneumatic tire includes lug grooves having alternating first and second groove portions. The first groove portion intersects an equator, extends in a width direction, and communicates with an adjacent second groove portion. The second groove portion inclines from the first groove portion at a smaller angle relative to a circumferential direction smaller than that of the first groove portion and extends to a tread edge on one side. The first groove portion is on a stepping side with respect to an end on the tread edge side. The second groove portions curve or bend and have an average angle in an inner region smaller than that of the second groove portions in an outer region. A maximum length in the width direction of center blocks defined by narrow grooves connecting adjacent second groove portions and the lug grooves is 25%-35% of a development width.

An end-group functionalized polymer having one or more end groups according to the general formula (I)

##STR00001##

wherein
R1 represents a saturated or unsaturated, linear or branched, preferably aliphatic, hydrocarbon group having from 1 to 20 carbon atoms which, in addition to C and H, may contain one or more heteroatoms, preferably independently of one another selected from O, N, S or Si;
R2, R3 are identical or different and represent saturated or unsaturated hydrocarbon groups having from 1 to 20 carbon atoms and wherein the hydrocarbon group may contain, in addition to C and H atoms, one or more heteroatoms, preferably selected from the group consisting of O, N, S and Si;
A represents a residue selected from the group consisting of O-R4-OH, R5-OH and R6-NH-R7, preferably O-R4-OH wherein R4, R5 and R6 represent a saturated or unsaturated linear or branched hydrocarbon group which, in addition to C and H atoms, may contain one or more heteroatoms, independently selected from O, N, S or Si and which contains from 1 to 20 carbon atoms and wherein
R7 represents H or a linear or branched or cyclic aliphatic or aromatic hydrocarbon group having from 1 to 20 carbon atoms and which, in addition to C and H atoms, may contain one or more heteroatoms, preferably selected from O, N, S or Si;
and wherein the polymer is a homopolymer of a conjugated diene or a copolymer of at least one or more conjugated diene and one or more vinylaromatic monomer and, optionally one or more other comonomers. Also provided are a process for making the polymers and articles made with the polymers.