Abstract: The present invention provides a nanocomposite of a star branched elastomer and a clay. The nanocomposite can be a mixture of a halogenated star branched elastomer and a clay, desirably an exfoliated clay, suitable for use as an air barrier. The halogenated star-branched elastomer can be the primary halogenated elastomer in the blend, and a ratio of the star-branched elastomer to clay can be from 2:1 to 500:1.

Abstract: To provide an amorphous silica powder suitable for a sealing material for semiconductors having improved HTSL properties and HTOL properties, and a process for its production. An amorphous silica powder containing Al in an amount of from 0.03 to 20 mass % as calculated as Al2O3 measured by atomic absorption spectrophotometry, wherein the average particle size is at most 50 ?m, and when the amorphous silica powder is divided according to the average particle size into two powders, a powder having a particle size smaller than the average particle size has a higher content as calculated as Al2O3 than a powder having a particle size larger than the average particle size.

Abstract: There is provided a rubber composition for a tread having excellent hardness and improving the processability and grip performance of a tire, and a tire comprising thereof. A rubber composition for a tread comprising 30 to 80 parts by weight of silica having a BET specific surface area of less than 150 m2/g and 10 parts by weight or less of carbon black based on 100 parts by weight of a rubber component comprising an epoxidized natural rubber, and a tire comprising thereof.

Abstract: A fluorine-containing elastomer composition, which comprises (A) a fluorine-containing elastomer consisting of a copolymer comprising (a) tetrafluoroethylene, (b) perfluoro(alkyl vinyl ether) or perfluoro-(alkoxyalkyl vinyl ether), and (c) a cyano group-containing perfluorovinyl ether, (B) a cross-linking agent, and (C) spherical silica, wherein the spherical silica is high purity amorphous silica particles obtained by calcining metallic silica powders, and cooling the resulting vaporous silicon oxide. The present fluorine-containing elastomer composition can provide seal materials having distinguished processability, product appearance, plasma resistance, etc. by the cyano group-containing perfluoroelastomer having a good heat resistance and only silica as contained therein.

Abstract: The present invention relates to a fiber reinforced nylon composition, wherein the composition includes (A) 25 to 75 parts by weight of a polyarylamide resin, (B) 25 to 75 parts by weight of a reinforcing fiber having a cross-sectional aspect ratio of 1.5 or more, and (C) an impact modifier, and the impact modifier is included in an amount of 1 to 10 parts by weight based on 100 parts by weight of a mixture of the polyarylamide resin and the reinforced fiber. According to the present invention, the fiber reinforced nylonresin composition may exhibit minimal or no warpage, can have excellent fluidity and impact resistance, and can provide high whiteness and a glossy-coating due to minimal or no surface change after dipping in boiling water.

Abstract: Visco-elastic tyre balancing compositions comprising 1) 85 to 97% by weight of a glycol ether component comprising one or more ethylene/propylene glycol copolymer ethers of the general formula (I) or the general (II) or mixtures thereof R—O{[CH(CH3)CH2—O—]m[CH2—CH2—O—]n}H (I) R1—(O—{[CH(CH3)CH2—O—]m[CH2—CH2—O—]n}H)2 (II) wherein R is hydrogen or an alkyl group of 2-8 carbon atoms; R1 is an alkylene moiety of 2-8 carbon atoms in which the two substituents are not carried on the same carbon atom; m is the mole percentage of propylene glycol in the ethylene/propylene glycol copolymer moiety or moieties; and n is the mole percentage of ethylene glycol in the ethylene/propylene glycol copolymer moiety or moieties, wherein the ratio n:m is in the range from 35:65 to 80:20; each glycol copolymer compound having a number average molecular weight in the range of 2000-10000; and 2) 3 to 15% by weight of a fumed silica gel former; said balancing compositions being visco-elastic 1500 Pa and 5000 Pa at 22° C.

Abstract: Physical properties and soiling resistance of polymer-bound inorganic composites such as artificial stone are improved by incorporating a silane adhesion promoter and at least one of three organosilicon compounds.

Abstract: A rubber composition for a tire having improved in low fuel efficiency, wet skid performance, abrasion resistance, and steering stability with favorable balance, and tire which has tread, using the same. A rubber composition for a tire, comprising 30 to 150 parts by weight of silica having a nitrogen adsorbing-specific surface area of 20 to 200 m2/g, and a pH of 7.0 to 12.0 when the silica is dispersed in water to be 5% aqueous solution, based on 100 parts by weight of a rubber component, and a tire which has a tread, using the same.

Abstract: Hydrolysates and/or condensates of epoxy- and silane-functional oligomers and polymers, prepared by hydrolyzing and/or condensing at least one oligomer and/or polymer (A) containing at least one epoxide group (a1) and at least one hydrolyzable silane group (a2); and also (meth)acrylate copolymers (A) containing lateral and/or terminal epoxide groups (a1) and lateral and/or terminal hydrolyzable silane groups (a2), in a molar ratio (a1): (a2) of from 15:1 to 1: 1.5, processes for preparing them, and their use.

Abstract: The invention aims to provide a tire rubber composition that is excellent in the low heat build-up property (fuel economy), wet grip performance, and abrasion resistance, and can be suitably used for a tread (cap tread); and a tire rubber composition that is excellent in the low heat build-up property and breaking properties, and can be suitably used for a base tread or sidewall.

Abstract: Fumed silicon dioxide powder with a BET surface area of 20 to 35 m2/g, characterized in that a) the number-based median particle diameter is 60 to 150 nm, and b) the proportion of particles with a diameter of 200 nm or more is at most 10%, and c) the proportion of particles with a diameter of up to 60 nm is at most 20%, based in each case on the total number of particles.

Abstract: The present invention provides a silica-containing heat curing silicone rubber compound composition which can be produced safely and hardly suffers from inclusion of foreign substances. More specifically, when (A) 100 parts by weight of a polyorganosiloxane base polymer and (B) 1 to 100 parts by weight of a reinforcing silica are mixed together, (C) 0.05 to 80 ppm of an ionic liquid whose anionic component is bis(trifluoromethanesulfonyl)imide is added thereto.

Abstract: Compositions and methods for treating metal substrates and/or bonding metal substrates to polymeric materials, such as rubber, are provided. The compositions include at least one substantially hydrolyzed amino silane and at least one substantially hydrolyzed sulfur-containing silane Optionally, the compositions include a nano-size particulate material. The compositions provide coatings on metal substrates for protecting the metal from corrosion and for adhering rubber-like polymeric compositions to the metal with polymer-to-metal vulcanization conditions less dependent on the coating thickness, and with use of less coating materials.

Abstract: A durable polyoxymethylene composition and a ramp made of the durable polyoxymethylene composition are disclosed. The durable polyoxymethylene composition of the present invention has excellent micro-wear-resistant property.

Abstract: A fluorine-containing curable composition which is less viscous, and which can produce a cured article having excellent heat resistance, chemical resistance, solvent resistance, and mechanical strength is provided. The fluorine-containing curable composition comprises (a) 100 parts by weight of a straight chain fluorine-containing polymer having at least two alkenyl groups per molecule represented by the following formula (1): said polymer having a number average molecular weight of 1,000 to 100,000; (b) a fluorine-containing organosilicon compound having at least 2 hydrogen atoms bonded to the silicon atom per molecule at an amount such that molar ratio of hydrosilyl group (SiH group) in the component (b) to the alkenyl group in the component (a) is in the range of 0.4 to 5.0; (c) a catalytic amount of a hydrosilylation catalyst; and (d) 1 to 100 parts by weight of a silica filler.

Abstract: The present invention provides an inkjet ink composition, which is excellent in dispersion stability, discharge reliability and suppression of lowering of liquid repellency of the inkjet head member, and which includes a pigment, a polymer compound, a water soluble organic solvent, a silicon compound and water, the polymer compound including a structural unit represented by Formula (1), a structural unit represented by Formula (2), and a structural unit represented by Formula (3); the water soluble organic solvent being a diol compound including a repetition structure formed from oxyalkylene groups having 2 or 3 carbon atoms; and the silicon compound being selected from the group consisting of colloidal silica and water-soluble alkali metal salts of silicic acid: wherein R1 to R3 each independently represents a hydrogen atom or a methyl group; R4 represents an alkyl group having 1 to 10 carbon atoms; and n is 1 to 20.

Abstract: The invention relates to biodegradable nano-polymer compositions, or nanocomposites, comprising poly(lactic acid) and co-polyester polymer with adipic acid compounded with nanoparticles of a mineral material having a degree of purity of at least 99.9%, preferably 99.99%, selected from the group of silica and magnesium silicate. In addition, the present invention refers to a process for manufacturing the said compositions as well as biodegradable articles made on the basis of such compositions, such as molded, formed and extruded articles.

Abstract: Adhesive and sealant systems based on epoxy resins, polyurethane, silane-terminated polymers, silicones, unsaturated polyester resins, vinyl ester resins, acrylates, polyvinyl acetate, polyvinyl alcohol, polyvinyl ether, ethylene vinyl acetate, ethylene-acrylic acid copolymers, polyvinyl acetates, polystyrene, polyvinyl chloride, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl rubber, polysulfide, polyethylene, polypropylene, fluorinated hydrocarbons, polyamides, saturated polyesters and copolyesters, phenol-formaldehyde resins, cresol-/resorcinol-formaldehyde resins, urea-formaldehyde resins, melamine-formaldehyde resins, polyimides, polybenzimidazoles, polysulfones, which contain 1 wt. % to 15 wt. % of a compacted, hydrophobic pyrogenic silica.

Abstract: Printed circuit boards are coated with nanoparticulate inorganic oxides. The coatings have increased partial discharge resistance.

Abstract: Moulded articles having reduced surface carbonization and longer retention of the mechanical properties and methods of producing same are presented. In an embodiment, the moulded article comprises polyamides with nanofillers, which can be produced by means of injection moulding or extrusion, in particular by extrusion blow moulding, coextrusion blow moulding or sequential blow moulding with and without 3D hose manipulation. For example, the polyamide moulding materials for the production of moulded articles have reduced surface carbonization in the moulded articles in subsequent long-term use at elevated temperatures.

Abstract: Particulate materials useful as fillers, reinforcing agents, radioopacifiers, or impact modifiers. The particulate material has an average particle size range of about 10,000 nm or less and comprises an organic-inorganic hybrid material that has a ceramic material network having organic polymer segments distributed throughout the ceramic network. The ceramic network may be prepared by a sol-gel technique. The particulate material may be compounded in thermoplastic polymer compositions useful in a variety of applications such as preparation of medical device components.

Abstract: Colloidal silica particles dispersed in a reactive monomer may cause the polymerization, degradation, or the like of the reactive monomer by an action of the solid acidity of the surfaces of the particles and a monomer may be polymerized during a process for producing a monomer-dispersed silica sol, or a stable silica sol may not be obtained. In addition, a polymer of a resin formed article etc. obtained by curing a monomer-dispersed silica sol may be deteriorated, degraded, or the like with time. Therefore, there are provided a reactive monomer-dispersed silica sol having high stability by reducing the solid acidity of the surfaces of the colloidal silica particles contained in the reactive monomer-dispersed silica sol, and a production method thereof, and a curable composition using the reactive monomer-dispersed silica sol, and a cured article in which the deterioration, the degradation, or the like of the polymer is suppressed.

Abstract: The invention provides methods and compositions having one-dimensional nanoparticle chains. A one-dimensional nanoparticle chain can comprise a linear substantially non-crosslinked polymer having pendant groups and asymmetrically functionalized nanoparticles attached to the polymer through the pendant groups. Additionally, an asymmetrically functionalized nanoparticle can comprise a nanoparticle core having an outer surface, a primary group of first ligands attached to a substantially continuous primary region of the outer surface, and a secondary group of second ligands attached to a substantially continuous secondary region of the outer surface, such that the primary group of first ligands and the secondary group of second ligands comprise a different ligand population.

Abstract: A resin composition for optical lenses and optical packaging includes (1) 1 to 99.99 wt % mixture of epoxy, siloxane and epoxy-siloxane copolymers, (2) 0.01 to 5 wt % catalyst and (3) 0 to 40 wt % curing agent. The mixture of epoxy, siloxane and epoxy-siloxane copolymers includes (1) 1 to 85 wt % epoxy and siloxane oligomers, based on total weight of the mixture; (2) 1 to 90 wt % siloxane containing at least one alkoxy group, based on total weight of the mixture; (3) 1 to 80 wt % a epoxy resin having a benzene ring with at least one epoxy group or a hydrogenated benzene ring, or aliphatic epoxy resin, based on total weight of the mixture; (4) 1 to 70 wt % epoxy resin containing at least one hydroxyl group and at least an epoxy group, based on total weight of the mixture.

Abstract: The invention relates to polymer nanocomposites comprising synthesized lamellar nanoparticles dispersed in a polymer matrix. The lamellar nanoparticles are synthetically made in a one-step operation by supramolecular assembly of a surfactant and a inorganic precursor and are exfoliated inside the polymer matrix.

Abstract: A synthetic-rubber-based composition that consists of a low-molecular-weight rubber selected from polybutadiene comprising about 75% to about 92% cis-1,4 units, sulfur, a vulcanization accelerator, and an active filler wherein the sulfur, accelerator, and active filler are each present in the form of powder having a particular particle-size range. Additionally, this composition may be used to form coatings and rubber concretes.

Abstract: A precipitated silica having a d50-value of from 150 to 2000 nm, a d90-value of from 500 to 7000 nm, a silanol group density of from 2.5 to 8 OH/nm2, and a modified tapped density of less than or equal to 70 g/l is useful for thickening and providing thixotropy in liquid systems and shows superior efficiency at thickening and creating thixotropy compared to existing grades of precipitated silica. The precipitated silica functions best as a thixotrope in non-polar or intermediate polar liquid systems such as unsaturated polyester (UPE) resin systems.

Abstract: An easily dispersible cake of precipitated silica, wherein the precipitated silica has a BET specific surface area of at least 220 m2/g. When the cake is dispersed in ion-exchange water to provide an aqueous dispersion of the silica of 5% by weight in concentration and further diluted to reduce the silica concentration to 1.5% by weight, the dispersion has a light-scattering index (n-value) of at least 2. The easily dispersible cake can be obtained by simultaneously adding an alkali silicate and a mineral acid to a reaction liquid whose pH is being maintained at a fixed value within a range of 7.5-11.5 and whose temperature is being maintained at 92-98° C., thus forming precipitated silica through their reaction, and separating the precipitated silica from the reaction liquid in wet state.

Abstract: The invention concerns an aqueous specific silica-based nanocomposite polymer dispersion, a method for preparing same, a coating composition, in particular protective, containing said dispersion, for applications requiring high anti-corrosive, anti-abrasive and chemical resistance performances. It concerns an aqueous nanocomposite polymer dispersion obtainable by an emulsion polymerization process of at least one monomer composition in the presence of at least one aqueous silica nanoparticle dispersion, said monomer composition being added at least in one step into the reactor already containing the aqueous silica nanoparticle dispersion, said aqueous silica nanoparticle dispersion having an anionic character and being stable in a pH range between 2 to 10, and said emulsion polymerization being performed in the presence of at least one organic initiator free of any ionic group and in the absence of any monomer or cationic dispersant.

Abstract: The present disclosure is directed to a base film having a thickness from 8 to 152 microns, a 60 degree gloss value from 2 to 35, an optical density greater than or equal to 2 and a dielectric strength greater than 1400 V/mil. The base film comprises a chemically converted (partially or wholly aromatic) polyimide in an amount from 71 to 96 weight percent of the base film. The base film further comprises a pigment and a matting agent. The matting agent is present in an amount from 1.6 to 10 weight percent of the base film, has a median particle size from 1.3 to 10 microns, and has a density from 2 to 4.5 g/cc. The pigment is present in an amount from 2 to 9 weight percent of the base film. The present disclosure is also directed to coverlay films comprising the base film in combination with an adhesive layer.

Abstract: Electrical insulation system, which optionally contains a filler material and/or further additives, wherein said electrical insulation system comprises poly(dicyclopentadiene) as the main component, and method of making said electrical insulation system.

Abstract: A primer composition for a polysiloxane hard coating is provided. This primer composition comprises (A) a vinyl polymer having a hydrolyzable silyl group and/or SiOH group and an organic UV absorbing group bonded to its side chain, and (B) fine silica particles dispersed in an organic solvent, and the primer layer formed after coating and curing has a coefficient of linear expansion of up to 150×10?6/° C.

Abstract: Surface-modified, fumed silica having the data: BET surface area, m2/g: 25-400; Average primary particle size, nm: 5-50; pH: 3-10; Carbon content, % by weight: 0.1-10; Potassium content (calculated as potassium oxide), % by weight: 0.000001-40; is prepared by subjecting a fumed silica to surface modification in the presence of potassium compounds. It can be used in LSR silicone rubber compositions as a filler.

Abstract: Hydrophobic precipitated silicas with a high pH and low silanol group density, a process for preparing them and their use, particularly in deformer formulations.

Abstract: There is provided a modified conjugated diene-based polymer having a silyl group substituted with one or more alkoxy groups, and one or more nitrogen atoms on the chain ends of a conjugated diene-based polymer, the modified conjugated diene-based polymer being obtained by polymerizing a conjugated diene compound, or copolymerizing a conjugated diene compound with an aromatic vinyl compound, by using a polyfunctional anionic polymerization initiator prepared from a polyvinyl aromatic compound and an organolithium compound in a range of a molar ratio (the polyvinyl aromatic compound/the organolithium compound) of from 0.05 to 1.0, so as to obtain the conjugated diene-based polymer, and by reacting a living polymer end of the conjugated diene polymer with the compound having a silyl group substituted with two or more alkoxy groups, and one or more nitrogen atoms.

Abstract: The invention involves composite materials containing a polymer foam and an aerogel. The composite materials have improved thermal insulation ability, good acoustic insulation, and excellent physical mechanical properties. The composite materials can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power. The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N2 or H2, adsorbs to the surfaces in aerogel particles. Thus, another embodiment of the invention provides a storage vessel for a cryogen.

Abstract: A process for forming a compatibilized silica and nitrile polymer blend in latex form is described herein. The process can include treating a silica with a coupling agent in aqueous suspension to form a compatibilized silica slurry. The coupling agent can have the capacity of chemically reacting with the surface of the silica to bond the coupling agent thereto. The process can include blending at least a portion of the compatibilized silica slurry into a styrene butadiene polymer latex, forming a silica styrene butadiene polymer latex, and blending at least a portion of the compatibilized silica slurry into an acrylonitrile butadiene polymer latex, forming a silica acrylonitrile butadiene polymer latex. The process can include blending the silica styrene butadiene polymer latex with the silica acrylonitrile butadiene polymer latex, forming the compatibilized silica and nitrile polymer blend.

Abstract: Polymer particles of improved mechanical hardness are provided, the polymer particles being subjected to a thermal cycle of heating and subsequently cooling. The polymer particles comprise combinations of preferably three monomers, the monomers having hydrophilic and hydrophobic groups in their polymer chain in order to achieve preferential orientation of the polymer chains in a polar solvent after applying the heating cycles of the invention (for example, but not limited to, polymethylmethacrylate and polystyrene based terpolymers and copolymers). Polymeric abrasives used in slurry compositions for polishing copper and their use in a chemical mechanical polishing method are also provided.

Abstract: Described are new custom postage printing stocks, coating compositions, processes for preparing and utilizing these and resulting postage products. Disclosed ink formulations comprise: invisible fluorescent dye and/or pigment (preferably red-fluorescent dye), which is fluorescent in the range of 580 to 640 nm when illuminated with light at 254 nm; water-soluble binder; substrate penetrant, fluorescence stabilizer; substrate anticurl agent and water. The inks, when coated on substrates and dried, can improve the quality and color of images printed as compared to images printed without the aid of the invention.

Abstract: Particles with a structural surface which are useful to produce abrasion resistant self-cleaning surfaces contain particulate solid particles having a superstructured overlayer of fine particles. The particles may be prepared by polymerizing a polymerizable siloxane, silane, or mixture thereof in a Pickering emulsion.

Abstract: Surface-modified silicas Surface-modified, highly structured, potassium oxide-doped silicas, characterized by BET surface area, m2/g: 25-400 average primary particle size, nm: 5-50 pH: 3-10 carbon content, % by weight: 0.1-10 potassium oxide content, % by weight: 0.000001-40 are prepared by subjecting a potassium oxide-doped silica to surface modification. It can be used as a filler in silicone rubber compositions.

Abstract: The present invention relates to a structural object coated with a superhydrophobic nanostructure composite, the structural object being obtained by densely coating a surface of a solid substrate having a desired shape with a nanostructure obtained by combining a polymer having a polyethyleneimine skeleton with silica on the nanometer order, and bonding a hydrophobic group to the surface of the nanostructure, and a process for producing the structural object. The present invention also relates to a structural object coated with a superhydrophobic nanostructure composite, the structural object being obtained by removing the polymer having the polyethyleneimine skeleton from the nanostructure and bonding a hydrophobic group to the surface of the residual nanostructure containing silica as a main constituent component, and a process for producing the structural object. Furthermore, the present invention provides a method of using the structural object as a container for transferring an aqueous solution.

Abstract: A seal member includes a hydrogenated acrylonitrile-butadiene rubber (HNBR) and carbon nanofibers. The seal member has a number of cycles to fracture of 7000 or more when subjected to a tensile fatigue test at a temperature of 70° C., a maximum tensile stress of 4 N/mm, and a frequency of 1 Hz. The seal member exhibits excellent abrasion resistance.

Abstract: Disclosed are a paste and a method for manufacturing a solar cell through screen printing said paste. The paste contains inorganic powder; an organic solvent; and a binder, and the inorganic powder has a tap density of 0.01 to 20 g/cm3. An etching mask pattern formed using said paste has good etch resistance in an etch-back process by which a selective emitter is formed, and thus, a stable emitter can be formed.

Abstract: An object of the present invention is to provide a golf ball material producing a high spin rate on approach shots and a low spin rate on driver shots and a golf ball using the same. The present invention provides a golf ball material having a ratio [Shore D/log(bending stiffness)] of Shore D hardness to a logarithm of bending stiffness (kgf/cm2) of 19.0 or more.

Abstract: The present invention is directed to a pneumatic tire having at least one component including a sulfur vulcanizable rubber composition, the rubber composition including at least one diene based rubber and at least one zinc naphthalocyanine compound.

Abstract: The present invention is directed to a pneumatic tire comprising at least one component, the at least one component comprising a rubber composition comprising: 100 parts by weight of at least one elastomer; from 10 to 80 parts by weight, per 100 parts by weight of elastomer (phr) of a high structure silica having a CTAB specific surface area (SCTAB) of between 40 and 525 m2/g, a BET specific surface area (SBET) of between 45 and 550 m2/g; and from 10 to 70 phr of a low structure silica having a median particle size of less than 500 nm, a specific area ranging from 15 to 25 m2/g, and a specific gravity of 2.1 to 2.3 g/cm3.

Abstract: The present invention provides a silicone resin composition comprising (A) an organopolysiloxane having at least two alkenyl groups, (B) an organohydrogenpolysiloxane having at least two hydrogen atoms each bonded to a silicon atom, (C) a catalyst comprising a platinum group metal, (D) fine silicone particles, and (E) a (meth)acrylate compound. The present silicone resin composition cures in a short time to form a cured product having excellent adhesion strength with solder resists and copper substrates.

Abstract: The present invention relates to the use of oxidic nanoparticles having an average particle size of 2 to 2000 nm in combination with at least one polycationic polymer as corrosion protection for metallic surfaces and also to a method of protecting metallic surfaces from corrosion, comprising the steps of: i) providing a formulation comprising oxidic nanoparticles (a) and at least one polycationic polymer (b) and an application medium, ii) applying the formulation to the metallic surface that is to be protected, and iii) optionally drying and/or heat-treating the surface.

Abstract: Pre-treatment solutions are provided, which can improve printing density and prevent bleeding and strike through when printing, particularly inkjet printing is performed with an oil ink on a printing medium that has been treated with the pre-treatment solutions. The pre-treatment-solution can be selected from the following (I), (II) and (III): (I): a pre-treatment solution which comprises at least inorganic particles with an average particle diameter of not less than 1 ?m and not more than 20 ?m and a solvent, in which the difference in solubility parameter (SP value) between the solvent of the pre-treatment solution and the solvent of the oil ink is not less than 1.0 (cal/cm3)1/2; (II): a pre-treatment solution which comprises at least inorganic particles with an average particle diameter of not less than 0.1 ?m and less than 1 ?m and a solvent, in which the difference in solubility parameter (SP value) between the solvent of the pre-treatment solution and the solvent of the oil ink is not less than 2.