427results about How to "Small coefficient of linear expansion" patented technology

The invention provides an opaque quartz crucible used in multicrystal silicon crystallization and a method for manufacturing the same. The crucible is of a regular square structure, and the compositions in mass ratio of the crucible are more than 99.7 Wt percent of silicon dioxide, less than 600ppm of aluminum oxide and less than 30ppm of ferric oxide. The method comprises the following steps: firstly, a raw material, i.e. high purity quartz is put into granulation equipment for wet method granulation, the grain size is controlled between 70 and 100mu m; then, slurry is fully stirred and then is fed into a gypsum mould under a pressure of between 2 and 3bar after being deposited for 24 to 48 hours; moreover, early grouting is assisted by slight vibration; the slurry is further settled for 5 to 8 hours, and is demoulded after fully dewatered; the slurry is dried inside a drier; and finally, a blank is put in a kiln for sintering so as to obtain the opaque quartz crucible. The proposal adopts grouting forming by a high-purity quartz material, and the sintered crucible has uniform inner structure; moreover, the crucible has excellent thermal shock stability and cracking resistance, and can meet the technological requirements for manufacturing multicrystal silicon cast ingots.

The invention discloses lead-free glass powder, a preparation method thereof, silver paste containing the glass powder and a crystal silicon solar cell manufactured by using the silver paste. The lead-free glass powder comprises the following components in percentage by weight: 20-30 percent of SiO2, 2-15 percent of B2O3, 40-70 percent of Bi2O3, 1-10 percent of ZnO, 1-10 percent of Al2O3 and 1-5 percent of BaO. The preparation method comprises the following steps of: (1) weighing the components for preparing a mixture; (2) putting the mixture into a crucible for melting; (3) performing water quenching on molten glass; (4) drying; (5) smashing the mixture into powder by planetary ball milling; and (6) screening. The needed silver paste is prepared from the lead-free glass powder, silver powder, an additive and an organic carrier. A solar panel front face electrode and a grid line are manufactured by performing screen printing and sintering on conductive silver paste on a cell substrate, so that the needed solar cell is obtained. The lead-free glass powder has low melting temperature, low softening temperature and low linear expansion factor.

The invention belongs to the field of refractory materials and discloses a preparation method of a fused silica refractory casting material unwetted by an aluminum liquid, which comprises the following step of: enhancing a ground substance by adopting 10-20wt% of white alundum powder, 4-8wt% of calcium aluminate cement, 3-5wt% of hydrated alumina compound binding agent, 4-10wt% of silicon oxide micropowder and 3-6wt% of alumina micropowder, wherein 60-70wt% of fused silica is used as a main material, BaSO4 and Na3AlF6 is adopted as a compound aluminum liquid anti-wetting agent with the addition of 1-6wt%, and additional 0.12wt% of trimeric sodium phosphate and additional 0.03wt% of sodium hexametahposphate are adopted as dispensing agents. The casting material prepared by using the method has high strength, is unwetted by the aluminum liquid, has the highest use temperature of 1000 DEG C and can be used as the refractory materials, such as an aluminum flowing groove of an aluminum smelting furnace and the like.

The invention relates to a manufacturing method of an electronic-grade polyimide film with low linear expansion coefficient. The method is characterized by comprising the steps that (1) the step-by-step condensation polymerization technology or the blending compounding technology is used for obtaining two or more polyamide acid glue solutions comprising rigid structures and soft structures at the same time and are different in rigidity and softness; (2) ultrafine inorganic whiskers, like zinc oxide whiskers, silicon carbide whiskers and zirconium tungstate whiskers, which are subjected to surface organic modification already and/or nanoparticle materials are smashed and cavitated through high-energy-density supersonic waves, and then the functional fillers are compounded with polybasic polyamide acid in an in-situ micro-nano mode; (3) the compounded glue solutions are subjected to filtration, vacuum defoamation, extrusion casting filming, chemical amidization or thermal amidization, infrared complete amidization, high-temperature thermal forming processing, corona processing and a reeling process, and therefore the electronic-grade polyimide film with the thickness being 7.5-125 micrometers, the linear expansion coefficient being 5-18ppm/DEG C, and good physical mechanical performance is obtained.

A process for preparing the polyether imide material as the base material of flexible printed circuit includes such steps as polycondensation between triphenyldiether tetrabasic acid bianhydride, biphenyl tetrabasic acid bianhydride, p-phenyldiamine and 3,3'-dimethyl-4,4'-diaminobibenzene, synthesizing polyamide, varnish, coating it on copper foil and high-temp. imidating. Its advantages are low expansibility and no curling.

The invention discloses a preparing method of liquid crystal epoxy resin oligomer and epoxy resin composition. The method comprises that: p-phenylphenol, epoxy chloropropane, phase transfer catalyst, sodium hydroxide and distilled water as raw materials are reacted to prepare the liquid crystal epoxy resin oligomer. The epoxy resin composition comprises: mixing the prepared liquid crystal epoxy resin oligomer and other raw materials based on weight proportionality: 10-30 parts of liquid crystal epoxy resin oligomers by weight, 10-30 parts of o-cresol-formaldehyde epoxy resins by weight, 5-25 parts of melamine modified linear phenol aldehyde resins by weight, 60-150 parts of spherical silicon micronized quartz powders by weight, 0.1-2 parts of curing accelerators by weight, 2-10 parts of flexibilizers by weight, 0.6-5 parts of resin acceptors by weight and 0.5-5 parts of lubricants by weight, which are mixed for smelting, crushed and demagnetizing to prepare the epoxy resin composition comprising side chain liquid crystal structure. The epoxy composition has good heat-resistant property and good physical mechanical property, is suitable for the encapsulations of large scale and grand scale integrated circuits.

The invention discloses a thermosetting plastic. The thermosetting plastic is characterized by comprising the following components in parts by weight: 60-95 parts of thermosetting resin, 5-40 parts of low-shrink additive, 150-300 parts of an inorganic mineral filler, 2-4 parts of an initiator, 0.6-1 part of calcium hydroxide micro powder, 2-6 parts of zinc stearate micro powder and 30-60 parts of glass fiber. In comparison with a conventional thermosetting plastic, the thermosetting plastic can be solidified more rapidly, high strength can be maintained within a wide temperature range, and the flame-retardant effect is good.

The invention relates to an ultra-high molecular weight polyethylene composition with the advantages of low melt viscosity, good flowability and high mechanical strength and softening temperature and a process method for producing an ultra-high molecular weight polyethylene composition tubular product. The composition comprises the following components in parts by mass: 100 parts of ultra-high molecular weight polyethylene of which the viscosity-average molecular weight is 3000000-5000000, 0.5-10 parts of polyethylene wax of which the molecular weight is 1000-5000, 10-40 parts of high-density polyethylene of which the molecular weight is 100000-500000, 20-50 parts of ultra-high molecular weight polyethylene of which the molecular weight is 8 millions-11 millions, 0.5-3 parts of a lubricant, 1-10 parts of a filling enhancer, 0.5-2 parts of nucleating agent, and 0.1-2 parts of a compound antioxidant. According to the invention, problems of high viscosity, poor flowability and difficulty in processing of the ultra-high molecular weight polyethylene melt in the prior art solved.

The invention discloses a molded plastic compound for sheet tantalum capacitor, which is an epoxy resin compound and belongs to the field of special-purpose plastic encapsulating material in electronic industry. The molded plastic uses epoxy resin as the main block resin and phenolic resins as curing agent, prepared by adding solidification accelerating agent, filling material, releasing agent, combustion inhibitor, coloring agent, coupling agent, toughening agent and modifier though the steps of disintegrating, mixing, pugging, cooling down, disintegrating, batch mixing, pre-forming and packaging.

This invention discloses a composite wax mold casting fireproof material, with 30-300 micron particle diameter, which uses quartz, bauxite, or silicate fireproof material as core, coated by aluminum oxide coating, wherein the said silicate fireproof material is kaolinite fireproof material or grammite. The material is produced by mixing the 10-250 micron diameter quartz, bauxite, or silicate fireproof material granules with aluminium collosol at 0.5-1.5:1, and drying granulating. The said drying granulating is performed by heat drying and then by disintegration or spray drying. When this composite fireproof material is used for coating material, it can efficiently prevent the soluble ions leaching in the original fireproof granules, greatly improve the coating material stability, and fully guarantee the quality of the casting articles, which will make it to be a cheap and superior wax mold casting fireproof material.

The invention relates to the technical field of composites and specifically relates to a graphene-like nano carbon nitride modified polytetrafluoroethylene friction material as well as a preparation method and application thereof. The graphene-like nano carbon nitride modified polytetrafluoroethylene friction material provided by the invention comprises the following preparation raw materials in parts by mass: 50-80 parts of polytetrafluoroethylene, 5-15 parts of polyimide, 5-10 parts of polybenzoate, 5-20 parts of aramid pulp, 5-15 parts of potassium titanate whiskers and 0.5-1.3 parts of graphene-like nano carbon nitride. The graphene-like nano carbon nitride modified polytetrafluoroethylene friction material prepared by adopting the raw materials with the proportions also has relativelylow mass wear rate and relatively high conversion efficiency on the basis of stable friction coefficient and is capable of meeting the demand for the friction material in an ultrasonic motor.

The invention relates to a wear-resistant heat preservation ceramic composite material which belongs to the field of materials and comprises primary materials and auxiliary materials according to weight percentage. The primary materials comprise corundum, chromic oxide, limestone, silicon dioxide, high alumina clay, silicate or calcium aluminate cement; the auxiliary materials comprise perlite powder, magnesia, quartz sand component, titanium oxide, dolomite, attapulgite, high temperature caking agent, composite strengthening agent, feldspar, and short carbon fiber component. The wear-resistant heat preservation ceramic composite material has the advantages of high intensity, being suitable for the strong eroding of various mediums, strong adhesive attraction, as well as excellent wear resistance and heat preservation performance. The wear-resistant heat preservation ceramic composite material has small coefficient of heat conduction, high melting point, and low linear expansibility. The integral performance is stable; the acid resistance, the alkali resistance and the erosion-proof capacity are strong; the density is small; a seamless integral wear-resistant heat preservation layer is formed after solidifying; the performance is extremely excellent; moreover, the wear-resistant heat preservation ceramic composite material is not easy to fall off, can effectively prolong the service lives of devices and pipelines, is convenient to be constructed, is used inside the pipelines, has the double effects of wear resistance and heat preservation, greatly reduces the production cost of enterprises, and improves the economic benefits thereof.

The invention provides a resin-based composite material with a controllable linear expansion coefficient and a preparation method thereof. The composite material is characterized by mainly comprising the following components in parts by weight: 10 parts of unsaturated polyester resin, 2-30 parts of filling material, 2-20 parts of fiber, 1-5 parts of low shrinking agent, 0.6-2 parts of mould release agent and 0.2-1 parts of initiator, wherein the filling material and fiber are materials with negative expansion coefficients or low expansion coefficients. The preparation method comprises the following steps: evenly mixing 1-5 parts of low shrinking agent, 0.6-2 parts of mould release agent and 0.2-1.5 parts of initiator with 10 parts of unsaturated polyester resin; then adding 2-30 parts of filling material and 2-20 parts of fiber for evenly mixing again; and finally, carrying out compression molding at the temperature of 140-160 DEG C. The linear expansion coefficient of the material provided by the invention is adjustable within a range of (8-30)*10<-6>/ DEG C, and the material provided by the invention has isotropy.

The invention discloses an epoxy molding compound and a preparation method thereof. The epoxy molding compound comprises the following components: epoxy resin, a coupling agent, a curing agent, a curing accelerator and filler, wherein the epoxy resin is o-cresol formaldehyde epoxy resin (ECN); a diluent is an epoxyactive diluent; the coupling agent is a silane coupling reagent; the curing agent is a latent curing agent; the curing accelerator is a latent curing accelerator; and the filler is silica powder. The thermal property, the mechanical property, the electric property and the like of the epoxy molding compound reach a balanced and relatively good level and can meet the requirements of the modern microelectronics packaging technology.

The invention relates to a manufacturing method of new nanometer materials, in particular to a manufacturing method of a high thermal conductivity artificial graphite film. The method comprises the steps that additive acid dianhydride, diamine compounds and organic polar solvent are polymerized in a reaction still to form a polyamide acid solution at certain temperature; the polyamide acid solution, imidize accelerant, a dehydrating agent, an end-capping reagent, a microwave heating material and a nanometer black liquor material are stirred in a stirred tank, are placed on a support to be in a film shape in a tape-casting mode and then are heated and dried in an oven, and polyimide films are obtained; the obtained polyimide films serve as raw materials, and are crossed, stacked, carbonized and graphitized, and finally the high thermal conductivity artificial graphite film is obtained. The manufacturing method is advanced in process, and the obtained graphite film has high thermal conductivity performance and good bending resistance.

The invention relates to the tubing product field produced by substance in plastic or plastic state, in particular to a high-strength pipe made by thermoplastic continuous fiber prepreg tapes and a manufacturing method and manufacturing equipment.The high-strength pipe made by thermoplastic continuous fiber prepreg tapes comprises an inner layer pipe (1), a core layer (2) and a surface layer pipe (3), all of which are sequentially sleeved from the inside to the outside. The manufacturing method for high-strength pipe made by thermoplastic continuous fiber prepreg tapes is characterized by comprising following steps: heating, fusion, extrusion, cooling and cutting.The manufacturing equipment for high-strength pipe made by thermoplastic continuous fiber prepreg tapes is characterized by comprising an extruder and a co-extrusion composite die which are arranged in sequence. The high-strength pipe is overpressure resistant, highly-rigid and is low in expansion.

The present invention provides a substrate applicable in a chip LED package, the substrate having a conductive layer, an insulation layer and a heat-dissipation plate in this order, wherein the insulation layer comprises a liquid crystal polyester soluble in a solvent and a sheet comprising inorganic fibers and/or organic fibers. The substrate has a small linear expansion coefficient of the insulation layer in the surface direction and is extremely useful for production of a chip LED package while having a practical heat resistance.