88results about How to "Little change in hardness" patented technology

To provide a flexible polyurethane foam which is excellent in low resiliency and durability without using a plasticizer and which shows little change in hardness against a change in temperature and at the same time, has high air permeability. A process for producing a flexible polyurethane foam, which comprises reacting a polyol mixture comprising polyol (A), polyol (B) and monool (D) with a polyisocyanate compound in the presence of a blowing agent etc. at an isocyanate index of at least 90. Polyol (A) is a polyether polyol having an average of 2-3 hydroxyl groups and a hydroxyl value of from 10 to 90 mgKOH/g, obtained by ring-opening addition polymerization of an alkylene oxide to an initiator using a double metal cyanide complex catalyst; Polyol (B) is a polyether polyol having an average of 2-3 hydroxyl groups and a hydroxyl value of from 15 to 250 mgKOH/g, other than the polyol (A); and Monool (D) is a polyether monool having a hydroxyl value of from 10 to 200 mgKOH/g.

The invention provides a method for preparing a Ti-Al-Nb alloy coating on a titanium metal surface. The method is characterized by comprising the steps of prefabricating a pressed slice of mixed powder formed by Ti powder, Al powder, Nb powder and Y2O3 powder and carrying out laser cladding treatment, wherein the step of prefabricating the pressed slice of mixed powder comprises the processes of firstly mixing the Ti powder, Al powder, Nb powder and Y2O3 powder uniformly with a ball mill, secondly drying the mixture and finally pressing the mixture into a slice on a press machine; the step of carrying out laser cladding treatment comprises the processes of putting the pressed slice on the cleaned titanium metal surface and then carrying out laser cladding processing. The method has the beneficial effects that the cladding process has excellent properties; the coating has dense tissue and is good in interface bonding; the main composition phases of the coating are Ti3Al and AlNb2; the change of the hardness of the coating along the cross section is small; the average hardness is about HV530-600, and the wear resistance is about three times that of a matrix; the composition elements of the Ti-Al-Nb alloy coating are resistant to oxidation and corrosion, so that the Ti-Al-Nb alloy coating has extensive application fields.

The invention relates to a synthetic method of slow resilience foam polyether polyol, which is characterized by adopting a polyalcohol compound as an initiator, and taking alkali metal as a catalyst and acetic anhydride as an end sealing agent to polymerize with epoxy compound at the pressure of 0-0.5 Mpa and at the temperature of 50-150 DEG C to obtain the slow resilience foam polyether polyol. The process is convenient for workers to operate; the technical index is easy to control; and the prepared new-type slow resilience foam polyether polyol can be used for various slow resilience foam products, and has the characteristic of smaller hardness change at the condition of temperature change.

The present invention provides a thermosetting polyurethane elastomer that is yellowing-free, has low hardness and does not give rise to bleeding without using any plasticizer, has little tack, and exhibits small changes in hardness with temperature.

This is achieved by a composition forming a yellowing-free, low-hardness polyurethane elastomer, containing no plasticizer and having (A) an isocyanate-terminated prepolymer and (B) a polyester polyol, wherein the isocyanate-terminated prepolymer (A) is an isocyanate-terminated prepolymer obtained by reacting hexamethylene diisocyanate with a glycol having an alkyl group as a side chain and having a molecular weight no greater than 500, and the polyester polyol (B) is a polyester polyol obtained from trimethylolpropane, 3-methyl-1,5-pentanediol and adipic acid, and having an average number of functional groups of 2.5 to 3.5 and a number average molecular weight of 800 to 5,000.

The invention discloses a high-strength spring wire of a high-elastic modulus and a preparation method thereof, and belongs to the technical field of high-strength spring wire technologies. differentproportions are carried out through raw materials relatively and easily obtained, forging and hot rolling are carried out after vacuum smelting and self-consumption smelting, finished sizes are obtained through cold-drawing by different deformations and heat treatment process, and the spring after enwinding is subjected to heat treatment to obtain spring parts with excellent performance. The high-strength spring wire of the high-elastic modulus has the advantages that the operation is simple, the cost is low, the combination property is excellent, and the high-strength spring wire of the high-elastic modulus can be used for other spring parts with strict environmental requirements; and the preparation method is simple in operation, energy saving and environmental protection are achieved, and the preparation method is suitable for industrial mass production.

The invention relates to fastening and anticorrosion technologies, in particular to a chemical holding multilayer cladding compound protection method applicable to a transmission tower with alternating loads in corrosion environment. Curing factice, non-curing factice, anti-corrosive tapes and adhesives are sequentially arranged on the surface of a protected structure. The curing factice is used for fastening and sealing the fastener, and the surface of a projected object to be coated needs to be subjected to treatment such as oil removal, rust removal and water removal. The non-curing factice is used for leveling a special-shaped structure; meanwhile, the curing factice is coated for building anaerobic environment; the chemical holding effect of the curing factice can be conveniently achieved; the alternating loads can be born; and the loosening is prevented. The adhesives are used for fast film forming; the adhesives and the anti-corrosive tapes are used for isolating the contact with corrosive media such as moisture and air in environment; the anticorrosion performance is good; and meanwhile, an effect of attractive appearance is achieved.

The invention relates to preparation of a novel silane macromolecular coupling agent. The initiator benzoyl peroxide initiates graft polymerization reaction of ethylene propylene diene monomer rubber (EPDM), methyl methacrylate (MMA), and gamma-methacryloxy propyl trimethoxyl silane (KH-570). By controlling the reaction conditions, a series of macromolecular silane coupling agents with different grafting ratios can be prepared so as to reach the purpose of adjusting the strength and modulus of the system and realize control and optimization of the interface structure between an inorganic filler and a matrix material. The invention is conducive to optimizing design of macromolecular coupling agents, thus better improving the comprehensive properties of the composite material.

The invention discloses a cold-resistant non-slip rubber sports shoe material and a manufacturing method thereof. The cold-resistant non-slip rubber sports shoe material is made of raw materials comprising a composite A and a composite B, the composite A includes butadiene rubber, natural rubber, butyl rubber, butadiene styrene rubber, white carbon black, naphthenic oil, stearic acid, zinc oxide, a first antiager, a second antiager, microcrystalline wax, a white smoke surfactant, a silane coupling agent and rosin resin; the composite B includes insoluble sulfur, a first accelerator and a second accelerator. The invention further discloses a manufacturing method of the cold-resistant non-slip rubber sports shoe material. The method includes the steps of material weighing, closed mixing, open mixing, dosing, vulcanization curve measuring and hydraulic molding. The cold-resistant non-slip rubber sports shoe material has cold-resistance, weather-proof and non-slip performances.

The invention discloses a preparation method of a conductive sponge. The preparation method has the beneficial effects that the sponge is compressed and stirred in conducting solution and glue solution respectively by adopting different compression and stirring methods in the preparation process of the conductive sponge, so that the prepared conductive sponge better adsorbs conductive particles and the glue better adheres to the conductive particles and the sponge, thus ensuring smaller surface resistance of the conductive sponge, more uniform distribution of volume resistance and smaller change of the hardness of the treated sponge.

The invention relates to a corrosion prevention technology, and in particular relates to an oxidation polymerization type corrosion prevention method which is suitable for iron and steel structures of electric power plants, stay cables of bridges, various storage tank edge plates, oil-gas pipelines, valves, flanges, H-section steel, spherical joints, screws, screw caps and mechanical equipment with various complex structures. According to the method, a corrosion prevention cream, a filling material and a corrosion prevention belt are arranged on the surface of a protected steel body in sequence, and then an adhesive is brushed on the outer surface layer of the corrosion prevention belt; the corrosion prevention cream can be used for filling corrosion hole parts, and can be used for construction with rust and original coatings, namely the surface of a protected object which is coated can be simply treated, so that the labor cost is saved, and the construction efficiency is high. The filling material is used at shaped parts of flanges, valves, storage tanks, spherical joints, screws, screw caps and the like, and is convenient in molding. The chemical compounds soaked on the corrosion prevention belt have good adhesive force, can obstruct the contact between metals and corrosive media including water, air and the like, and has good corrosion prevention performance; the corrosion prevention belt has good flexibility and structural displacement tracing ability and can be closely matched with the protected article.

The invention discloses a polyester tangential belt having a long service life, and a manufacturing method thereof. The polyester tangential belt comprises an upper rubber transmission layer, an upperbuffer layer, a skeleton layer, a lower buffer layer and a lower rubber friction layer which are sequentially adhered from top to bottom, the upper buffer layer includes at least one set of a first elastomer layer and a second elastomer layer which are sequentially adhered from top to bottom, or at least one set of the second elastomer layer and the first elastomer layer which are sequentially adhered from top to bottom; the lower buffer layer includes at least one set of the first elastomer layer and the second elastomer layer which are sequentially adhered from top to bottom, or at least one set of the second elastomer layer and the first elastomer layer which are sequentially adhered from top to bottom; and the first elastomer layer is a TPU sheet layer having a hardness of 95A, and the second elastomer layer is a TPU sheet layer having a hardness of 85A. The single structure of every buffer layer is changed, and the TPU sheets with different hardness values and different thicknesses are compounded, so the strength at the joint is increased, and the purpose of prolonging the service life is achieved.

The invention provides a preservation method of fresh-cut avocados based on film coating and liquid nitrogen quick-freezing. The method comprises the following steps: cleaning and disinfecting fresh avocados, and performing pit removing, peeling, dicing, color protection and film coating treatment; performing quick-freezing in a liquid nitrogen environment, wherein the quick-freezing temperature is -150 DEG C to -50 DEG C, the quick-freezing time is 5-30min and the heat insulation time is 2-30min; and then performing preserving in a condition not lower than -18 DEG C. The preservation method combines film coating treatment with the liquid nitrogen quick-freezing regulation and control technique, the preservation time of the quick-frozen avocados is as long as half a year, and the avocadosthawed at normal temperature have complete shapes, almost no brown stains and small variation in color and hardness. The preservation method maintains the nutrients, mouthfeel and flavor of the avocados, effectively prevents the avocados from browning, preserves the quality and freshness, prolongs the preservation time, is favorable for preparing avocado products with better mouthfeel, is safe, low-carbon and environmentally friendly and has broad application prospects.

Provided are an oil/fat composition for spreads, an oil/fat composition for butter cream, an oil/fat composition for kneading, and an oil/fat composition for layered food products, the oil/fat compositions being particularly improved in terms of shape retainability, change in hardness caused by long-term storage, and the seepage of liquid oil due to high temperature and/or the lapse of time, and also having satisfactory texture, flavor, and other required physical properties. This oil/fat composition includes a transesterified oil/fat (A) in which the contents of lauric oil/fat (A1) and palm oil/fat (A2) and the iodine value of the entire oil/fat are set within specific ranges. Further, in this oil/fat composition, the total percentage of disaturated triglycerides and trisaturated triglycerides, the mass ratio (SUS/SSU) between symmetrical triglycerides (SUS) and asymmetrical triglycerides (SSU) among disaturated triglycerides, the percentage of triglycerides in which the total carbon number of the constituent fatty acid is from 40 to 48, etc., are set within specific ranges.

The invention relates to the technical field of antiseptic preservation of plant materials and preparation of specimens, in particular to a preparation method of bamboo shoot specimens. According to the method disclosed by the invention, a mixed solution of glacial acetic acid, formalin and white granulated sugar is used as an infusion solution in the infusion process, and 45-55ml of glacial acetic acid, 15-25ml of formalin and 48-52g of white granulated sugar are added into every 1000ml of distilled water. The method has a very ideal preservation effect on the bamboo shoots, after long-time preservation, the bamboo shoot specimen preservation liquid is free of turbidity and extremely few in sediment, the bamboo shoot specimen is good in bamboo shoot body integrity, the sheath compactness and the bamboo shoot meat hardness change are not obvious, the distortion phenomenon is avoided, the problems of decoloration, sheath color gradual whitening and the like are avoided, and the fidelity effect is good.

A flexible polyurethane foam for a cushioning material, the flexible polyurethane foam comprising a polyol and an isocyanate as main components, and a fluoride surfactant as a cell regulator, wherein the fluoride surfactant has the structure of a perfluoroalkyl group, exhibits a foaming height of 3 mm or more in a toluene solution containing thereof in a concentration of 0.1% by mass or an aqueous ethanol solution in a concentration of 60% by mass five minutes after the toluene solution of the aqueous ethanol solution is stirred.

The invention discloses a high-temperature-aging-resistant chloroprene rubber windshield wiper rubber strip and a preparation method thereof. The high-temperature-aging-resistant chloroprene rubber windshield wiper rubber strip comprises chloroprene rubber, carbon black, an anti-aging agent, a plasticizer, a processing aid, an accelerant, zinc oxide and magnesium oxide. The preparation method comprises the following steps: plastifying chloroprene rubber, pressurizing and banburying with the anti-aging agent and the plasticizer, adding carbon black, the processing aid and magnesium oxide, carrying out internal mixing, adding zinc oxide and the accelerant, carrying out internal mixing, discharging the rubber material when the temperature reaches 100-150 DEG C, carrying out re-mixing on an open mill for 3-6 minutes, pressing into a rubber sheet with an appropriate size by using a tablet press, standing for later use, putting the rubber sheet obtained in the step A into a special mold forthe windshield wiper rubber strip of a compression molding machine, molding for 3-10 minutes at the molding temperature of 150-180 DEG C to obtain a semi-finished product of the chloroprene rubber windshield wiper rubber strip, and performing post-treatment, cleaning, cutting, plasma treatment, spraying and other processes on the semi-finished windshield wiper rubber strip obtained in the step B to obtain the finished chloroprene rubber windshield wiper rubber strip.

The invention discloses a special rubber compound for a paper conveying rubber roll of printing paper. The special rubber compound is prepared from the following components in percentage by weight: 46 percent to 55 percent of butadiene styrene rubber, 15 percent to 20 percent of white carbon black, 15 percent to 20 percent of reinforcing fillers, 4 percent to 9 percent of a softening agent, 2 percent to 5 percent of other compounding ingredients, 2 percent to 5 percent of an anti-ageing agent, 1.5 percent to 2.3 percent of a vulcanizing accelerator and 2 percent to 5 percent of an antistatic agent. The special rubber compound disclosed by the invention has the advantages of good ozone-resisting performance, small rigidity changes, high tensile strength, easiness of machining, good wearing resistance, antistatic property and stability, excellent comprehensive performances and low cost, and can meet the use requirements of current paper conveying rubber rolls of a printer.