30results about How to "Low linear expansion coefficient" patented technology

To provide an alkali-free glass substrate, which has a high Young's modulus, a low linear expansion coefficient, a high strain point and a low density, does not devitrify in the float forming process and is excellent in acid resistance.An alkali-free glass substrate, which contains neither alkali component nor BaO and consists essentially of, as represented by mol % based on oxide, from 57.0 to 65.0% of SiO2, from 10.0 to 12.0% of Al2O3, from 6.0 to 9.0% of B2O3, from 5.0 to 10.0% of MgO, from 5.0 to 10.0% of CaO and from 2.5 to 5.5% of SrO, provided that MgO+CaO+SrO is from 16.0 to 19.0%, MgO / (MgO+CaO+SrO)≧0.40, and B2O3 / (SiO2+Al2O3+B2O3)≦0.12; wherein Young's modulus ≧75 GPa; the linear expansion coefficient at from 50 to 350° C. is from 30×10−7 / ° C. to 40×10−7 / ° C.; the strain point ≧640° C.; the temperature T2 (the viscosity η satisfies log η=2)≦1,620° C.; the temperature T4 (the viscosity η satisfies log η=4)≦1,245° C.; the devitrification temperature ≦T4; and weight loss per unit area is at most 0.6 mg / cm2, when immersed in 0.1N HCl at 90° C. for 20 hours.

The present invention aims to provide a curable resin composition which gives a cured product having a low linear expansion coefficient. The curable resin composition of the present invention contains, as essential components, (A) an organic compound having at least two carbon-carbon double bonds reactive with SiH groups per molecule, (B) a compound containing at least two SiH groups per molecule, (C) a hydrosilylation catalyst, (D) a silicone compound having at least one carbon-carbon double bond reactive with a SiH group per molecule, and (E) an inorganic filler.

A polyimide containing at least one of repeating units represented by the following general formulae (1) and (2):wherein the formulae (1) and (2), R1, R2, and R3 each independently represents a hydrogen atom or the like, R4 represents an aryl group having 6 to 40 carbon atoms, and n represents an integer of 0 to 12, wherein a total amount of the repeating units represented by the general formulae (1) and (2) is 90% by mole or more relative to all repeating units.

The present invention provides a formed article, or more specifically a transparent substrate, which effectively utilizes a natural stuff and which has a low linear expansion coefficient, a high light transmittance and an appropriate level of moisture permeability. The transparent substrate includes at least an oxidized polysaccharide and has a linear expansion coefficient of 50 ppm / ° C. or less at 30-150° C. and a light transmittance of 70% or more at 660 nm. Its manufacturing method includes an oxidation process in which cellulose reacts with TEMPO or its derivatives as a catalyst to be oxidized in water under the presence of a co-oxidant, along with a fiberizing process in which the oxidized cellulose is fiberized in water to form a cellulose fiber, and a substrate-forming process in which a transparent substrate is formed from a cellulose dispersion liquid containing the cellulose fiber.

A fluoropolymer molding method and the resulting molded article are disclosed where the fluoropolymer is composed of fluoropolymer particles each having a multi-layer structure that consists of at least two types of fluoropolymers having different melting points, with at least one inner layer made of a fluoropolymer with a melting point higher than that of the outermost fluoropolymer. The fluoropolymer of the at least one inner layer is molded at a temperature higher than the melting point of the lowest melting point of the fluoropolymers that form the outermost layers of the multi-layer-structure fluoropolymer particles, and lower than the melting point of the fluoropolymer having the highest melting point. The resulting articles have excellent chemical liquid resistance and gas impermeability and low linear expansion coefficient.

Provided is a polycarbonate resin composition containing 1-20 parts by weight of an amorphous thermoplastic resin having a glass transition temperature of not lower than 110° C., and 1-50 parts by weight of plate-shaped fillers having a number average major axis length of 0.5-45 μm, with respect to 100 parts by weight of a matrix resin component containing 35-95 wt % of a polycarbonate resin and 5-65 wt % of a thermoplastic polyester resin.

The present invention provides a process for producing an oriented thermoplastic polyester resin sheet which is excellent in tensile strength, tencile modulas and heat resistance, and a light laminate-molded body using the same, which has a low linear expansion coefficient and is excellent in impact resistance, durability, easiness of handling, productivity, and others. A process for producing an oriented thermoplastic polyester resin sheet, which includes: pultrusion-drawing a thermoplastic polyester resin sheet in an amorphous state at a temperature from the glass transition temperature of the thermoplastic polyester resin −20° C. to the glass transition temperature of the thermoplastic polyester resin +20° C.; and then drawing the resultant uniaxially at a temperature higher than the temperature for the pultrusion-drawing. A laminate-molded body, wherein a thermoplastic resin layer is laminated on each of the surfaces of the resultant oriented thermoplastic polyester resin sheet.

A novel polyimide compound which has a low linear expansion coefficient and permits film formation by a spin coating method or the like, a preparation method for the polyimide compound, and an optical film and an optical waveguide produced by employing the compound. The polyimide compound has a structural unit represented by the following general formula (1):wherein X is a covalent single bond, —CH2—, —C(CF3)2— or —CR(R′)— (wherein R and R′, which may be the same or different, are each a C1 to C6 alkyl group or an aryl group); A and B, which may be the same or different, are substituents each selected from a hydroxyl group, a halogen group and a C1 to C4 alkyl group; a and b, which are the numbers of the substituents A and B, respectively, are each an integer of 0 to 2; and o, p and q are each an integer of 1 to 5.

The silica sol of the invention contains silica particles having a mean primary particle size of 20 to 100 nm and which has a silica particle size / mean primary particle size ratio, determined through dynamic light scattering, of 3.0 or less, wherein the silica particles are surface-treated with an organic silane compound and have an α-ray emission rate of 0.005 counts / cm2·hr or less and a moisture absorption coefficient, determined after allowing the silica particles to stand for 48 hours at 23° C. and a relative humidity of 50 RH %, of 0.5 mass % or lower.

The present invention relates to a molded article exhibiting a low linear expansion coefficient and a method of producing the molded article. The molded article is molded from a resin composition containing at least a thermoplastic cyclic olefin resin and silica particles surface-modified with amino functional groups and having a number average particle diameter of primary particles of 10 nm or more and 50 nm or less. The resin composition contains the silica particles in an amount of 34% by mass or more and 85% by mass or less.

The epoxy resin composition of the present invention is characterized in that a polyamide compound having a moiety derived from a hydroxyl substituted aromatic amine having a phenolic hydroxyl group adjacent to an amino group is used as an epoxy resin hardener.

Disclosed herein is a method of preparing a high-melting point flame retardant crystal, comprising the steps of: reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with 1,4-naphthoquinone in an inert solvent having a dielectric constant of 10 or less to reduce a content of by-products, thereby obtaining a reaction composition; and dissolving the reaction composition in any one solvent selected from the group consisting of ethyleneglycol, propyleneglycol, diethyleneglycol, cyclohexanone, benzyl alcohol, acetate ester, benzoate ester and a mixture thereof to recrystallize and refine the reaction composition, thereby obtaining high-melting point retardant crystal, represented by Formula 1, having a start melting point of 280° C. or more and a melting point of 291° C. or more, which are measured by differential thermogravimetric analysis.