Disclosed is an oil-containing fiber-polymer self-lubricating composite material. The composite material includes a resin matrix and an oil-containing fiber dispersed in the resin matrix, wherein a mass ratio of the resin matrix to the oil-containing fiber is in the range of 100:(1-10); the resin matrix is a photocurable resin or a thermosetting resin; the oil-containing fiber comprises a natural fiber and a lubricating oil adsorbed in the natural fiber.

A polymer comprising units having the structure (I): ##STR00001##
wherein x is 2 or 3, wherein L is (CH.sub.2).sub.y, where y is an integer from 1 to 10, or wherein L is CH(CH.sub.3)CH.sub.2S(CH.sub.2).sub.z, where z is an integer from 1 to 5; wherein [Q] is absent or is a polymerised moiety consisting of units having the structure (II): ##STR00002##
wherein R is a hydrocarbyl group, or a hydrocarbyl group containing one or more heteroatoms, wherein R may be linear, branched or cyclic, saturated or unsaturated, and wherein R has from 1 to 30 carbon atoms; wherein [Q] either consists of identical units of structure (II), or wherein [Q] consists of more than one different units of structure (II), differing in group R; and wherein X is a halogen or another chain terminating group. The polymers may find use as additives in lubricating compositions where they provide friction improvement and wear reduction.

Provided is an anti-wear agent capable of furnishing an epoxy resin coating film with anti-wear properties. The anti-wear agent is characterized in containing an alicyclic difunctional epoxy and a polymerization initiator or is characterized in containing a difunctional bisphenol A-type epoxy resin, a leveling agent and a polymerization initiator.

A sliding member includes a back metal layer and a sliding layer on the back metal layer. The sliding layer includes a synthetic resin matrix and graphite particles dispersed in the matrix in a volume ratio of 5-50% of that of the sliding layer. The graphite particles are composed of spheroidal and flake-like particles. The flake-like particles have a volume ratio of 10-40% of total graphite particles. The spheroidal particles have a cross-sectional structure with a plurality of AB planes of a graphite crystal laminated along a curved particle surface, from the surface toward a center direction. The flake-like graphite particles have a cross-sectional structure with the plurality of AB planes laminated in a thickness direction of the thin plate shape. The spheroidal particles have an average particle size of 3-50 μm, and the flake-like graphite particles have an average particle size of 1-25 μm.

A coating composition for the piston of an internal combustion engine comprises 10-30 wt. % of phenolic resin, 10-30 wt. % of epoxy resin, 10-30 wt. % of at least one solid lubricant selected from the group consisting of graphite, MoS.sub.2, WS.sub.2 and BN, and 5-30 wt. % of Fe.sub.2O.sub.3 particles.

A threaded tubular connection for drilling or operating hydrocarbon wells contains a portion of a tubular element with a male end having an axis of revolution and provided with a first threading extending about the axis of revolution, the male end portion being complementary with a portion of a tubular element with a female end having an axis of revolution and provided with a second threading extending about the axis of revolution, the male and female end portions being capable of being connected by makeup, each of the male and female end portions further comprising a sealing surface with a metal-metal interference, wherein the threading and the sealing surfaces of the male and female end portions are coated with a metallic anti-corrosion and anti-galling layer wherein zinc (Zn) is the major element by weight. One of the metallic anti-corrosion and anti-galling layers is coated with a passivation layer and the other is at least partially coated with a lubricant layer.

A polymer comprising units having the structure (I):

##STR00001##

wherein x is 2 or 3, wherein L is (CH.sub.2).sub.y, where y is an integer from 1 to 10, or wherein L is CH(CH.sub.3)CH.sub.2S(CH.sub.2).sub.z, where z is an integer from 1 to 5; wherein [Q] is absent or is a polymerised moiety consisting of units having the structure (II):

##STR00002##

wherein R is a hydrocarbyl group, or a hydrocarbyl group containing one or more heteroatoms, wherein R may be linear, branched or cyclic, saturated or unsaturated, and wherein R has from 1 to 30 carbon atoms; wherein [Q] either consists of identical units of structure (II), or wherein [Q] consists of more than one different units of structure (II), differing in group R; and wherein X is a halogen or another chain terminating group. The polymers may find use as additives in lubricating compositions where they provide friction improvement and wear reduction.

A sliding member of the present embodiment includes a bearing alloy layer and a coating layer provided on a sliding surface side thereof. The coating layer has a resin binder with sulfide particles dispersed therein. A covering portion is provided over specific particles and is made of metal oxide comprising the same metal element as a metal element constituting the sulfide particles. When measured by an X-ray photoelectron spectroscopy and an X-ray diffraction method, a ratio of a peak height of the metal oxide to a peak height of metal sulfide by the X-ray photoelectron spectroscopy is from 0.10 to 0.50, and a ratio of the peak height of the metal oxide to the peak height of the metal sulfide by the X-ray diffraction method is 0.10 or less.

A sliding member of the present embodiment includes a bearing alloy layer and a coating layer provided on a sliding surface side thereof. The coating layer has a resin binder with sulfide particles dispersed therein. A covering portion is provided over specific particles and is made of metal oxide comprising the same metal element as a metal element constituting the sulfide particles. When measured by an X-ray photoelectron spectroscopy and an X-ray diffraction method, a ratio of a peak height of the metal oxide to a peak height of metal sulfide by the X-ray photoelectron spectroscopy is from 0.10 to 0.50, and a ratio of the peak height of the metal oxide to the peak height of the metal sulfide by the X-ray diffraction method is 0.10 or less.

The invention concerns a threaded portion of a tubular element for a threaded tubular connection having an axis of revolution, the portion comprising a threading extending over its outer or inner peripheral surface, and a first sealing surface on the peripheral surface, the first sealing surface being capable of producing metal-metal interference with a corresponding second sealing surface belonging to a complementary threaded portion. The threading and the first sealing surface are coated with a metallic anti-galling layer wherein zinc (Zn) is the major element by weight, the metallic anti-galling layer being at least partially coated with a lubricant layer comprising a resin and a dry solid lubricant powder dispersed in the resin.