1158results about How to "Good chemical properties" patented technology

The invention discloses a preparation method and application of modified polyurethane aqueous dispersions of polyisocyanate curing agents. The preparation method comprises the following steps of: carrying out prepolymerization reaction by using polyester polyol, vulcabond monomer and a polyisocyanate curing agent; reacting with a hydrophilic chain-extending agent and a micro-molecule chain-extending agent to obtain polyurethane prepolymer containing hydrophilic groups (carboxyl or sulfonic groups) and isocyanate(NCO)-terminated groups; neutralizing the polymer into salt, and then dispersing the salt into water; and preparing the modified polyurethane aqueous dispersions of the polyisocyanate curing agents by the chain extending of a polyamine chain-extending agent. The modified polyurethane aqueous dispersions of the polyisocyanate curing agents have self-crosslinking function at room temperature, and the self-crosslinking density is over 85%. Compared with non-modified polyurethane aqueous dispersions prepared under the same condition, the modified polyurethane aqueous dispersions have superior film forming property, water resistance, alcohol resistance, pollution resistance, cold resistance, dry / wet rubbing resistance and chemical solvent resistance; and coating films have especially high drying speed, high hardness increment speed and high final hardness.

The invention relates to a high-sealing polyacrylic ester dispersoid and a preparation method thereof; a multi-element emulsifier system which consists of an anionic emulsifier and a compound non-ionic emulsifier is adopted for controlling the charging process and components of the emulsifier in different polymerization periods, and the room-temperature self-crosslinking high-sealing polyacrylic ester dispersoid is prepared by a semi-continuous seeding emulsion polymerization process. The dispersoid has small particle size, good electrolyte-resistance (calcium ion) stability and high tolerance to various film forming accessory ingredients (various organic solvents with high boiling point). The dispersoid is used as seal coat of water-based wood coating and has good sealing performance to various woods; harmful volatile organic compounds (VOC) such as formaldehyde, and the like sealed against escaping from plates to pollute indoor environment, and the colored compounds such as turpentine, pine oil and tannin and the like are sealed against dissolving out of the plates to pollute pure top coating and white top coating of a water-based wooden ware; and in addition, the dispersoid can be used in water-based leather finishing agents.

The invention discloses composite epoxy anticorrosive paint and a preparation method thereof. The composite epoxy anticorrosive paint is composited by a component A and a component B at a ratio of 2:1, wherein the component A comprises constituents as follows: organosilicon modified epoxy resin, a pigment, filler, a plasticizer, a dispersant, a coalescing agent and a antifoaming agent; the component B comprises constituents as follows: polyphenyl ether resin powder, styrene-butadiene rubber, toluene, a plasticizer, a coupling agent, auxiliary materials and a flame retardant; and the components A and B are mixed respectively for preparation, and B is sprayed on A to form the composite epoxy anticorrosive paint. The composite epoxy anticorrosive paint is prepared by two components, has superior high-temperature resistance and abrasion resistance as well as good adhesion and low shrinkage simultaneously, has good corrosion resistance and penetration resistance to water, medium acid, alkali and other solvents and further has superior flexibility and paint application simultaneously; and the preparation method of the composite epoxy anticorrosive paint is simple and low in cost.

The invention discloses a hydroxypolyacrylate emulsion, and a preparation method and an application thereof. The preparation method comprises the following steps: weighing an acrylate monomer and / or a metacrylate monomer, a hydroxyacrylate monomer, an acrylic monomer, an acrylate function monomer and a hydroxy oligomer, uniformly mixing to prepare a monomer mixture, weighing 10-15% of the monomer mixture, and emulsifying by using an emulsifier to prepare a seed pre-emulsion for later use; and adding the emulsifier, sodium bicarbonate and deionized water into a reaction kettle, stirring, rising the temperature of a reaction system, adding an initiator, stabilizing, adding the seed pre-emulsion in a dropwise manner, stabilizing, adding the remaining monomer mixture and the remaining initiator in a dropwise manner, heating, slaking, cooling, neutralizing, carrying out heat insulation, cooling, and discharging to obtain the hydroxypolyacrylate emulsion. A film made by using an aqueous dual-component polyurethane coating prepared from the hydroxypolyacrylate emulsion and an aqueous polyisocyanate curing agent has the advantages of high hardness, high luster and excellent chemical resistance.

The present invention discloses one kind of composite material of modified micro plant fiber powder and natural rubber and its preparation process and application. The composite material includes natural rubber or latex 100 weight portions, modified micro plant fiber powder 1-60 weight portions, sulfur 0.5-3.3 weight portions, promoter 1.2-4.3 weight portions, antiager 1-3 weight portions and other assistant. The preparation process includes mixing, forming, vulcanizing and other steps. The composite material has high tensile strength, high tearing strength, high ageing resistance, high virus permeation resistance, etc. and may be used widely in making urinary catheter, blood transfusion tube, condom, medical gloves and other products.

The invention relates to a waterborne heat-insulating flame-retardant multifunctional nano coating and a preparation method thereof. The coating consists of the following components in part by weight: 48 to 52 parts of waterborne resin and 30 to 50 parts of nano pigment fillers (nano titanium dioxide, nano titanium dioxide-coated hollow glass microspheres, nano titanium dioxide-coated hollow ceramic microspheres and nano antimony-doped tin dioxide (ATO) particles), size and auxiliary materials such as film-forming additive and coupling agent. The preparation method includes the steps that: the nano fillers and the size are first dipped into the waterborne resin, the auxiliary materials are then sequentially added and stirred, and thereby the heat-insulating flame-retardant multifunctional nano coating is obtained. The processing technique is simple, the component proportion is reasonable, and the prepared coating has the advantages of high heat resistance, high reflectivity, high radiative heat conductivity, certain fire resistance, high-efficient heat insulation, excellent mechanical and chemical properties, environment-friendliness, stain resistance, flame retardance and energy saving. The coating can be coated on outside facilities such as outer walls and building roofs.

The invention discloses high-temperature (800 DEG C) wear-resistant paint and a preparation method thereof. The high-temperature wear-resistant paint comprises a component 1 and a component 2, wherein the component 1 is prepared by mixing a component A and a component B; the component A in the component 1 comprises the following components: black silicon carbide, fine-grain aluminum oxide, dispersing agent, zinc oxide, modified epoxy resin, flatting agent and an auxiliary material; the component B in the component 1 comprises the following components: organic silicon modified epoxy resin, a filler, antimony trioxide, film-forming assistant and thickener; and the component 2 is curing agent and coupling agent. The high-temperature (800 DEG C) wear-resistant paint is prepared by the following steps: mixing the component A and the component B in the component 1, and curing the component 1 with the component 2. The high-temperature wear-resistant paint is prepared by compounding the double components, has excellent high temperature resistance and wear resistance, and also has the fine properties of favorable hardness, high heat stability, ductility, workability and the like. The invention also designs the method for preparing the high-temperature wear-resistant paint. The preparation method is simple and low in cost.

The invention relates to saline-alkali soil paddy rice special-purpose carbon-based organic fertilizer. The saline-alkali soil paddy rice special-purpose carbon-based organic fertilizer has a low cost and high fertilizer efficiency, is economic and environmentally friendly, improves a soil water binding capacity and permeability, and has functions of keeping fertility, slowly releasing fertilizer and reducing paddy rice salinization. The saline-alkali soil paddy rice special-purpose carbon-based organic fertilizer comprises biomass charcoal, chicken manure, pyroligneous liquor, fermented soybean meal and potassium humate. The biomass charcoal is prepared by thermal cracking charring of biomass raw materials under anoxic conditions. The saline-alkali soil paddy rice special-purpose carbon-based organic fertilizer can be used for paddy rice plantation, can improve a saline-alkali soil environment and can improve an organic paddy rice yield.

The invention discloses a high-voltage high-energy-density lithium ion battery which comprises a positive pole piece, a negative pole piece, a diaphragm, electrolyte and a shell, wherein the positive pole piece comprises a positive active material, a conducting agent, an adhesive and a current collector, and the weight percents of the positive active material, the conducting agent and the adhesion are 92 to 97%: 2 to 3.5%: 1 to 6%; the negative pole piece comprises a negative material, a conducting agent, an adhesive and a current collector, and the weight percents of the negative material, the conducting agent and the adhesive are respectively 90 to 96%, 1 to 5% and 4 to 10%; the lithium ion battery is prepared by adopting modified lithium cobalt oxides (LiCoO2) as the positive active material and the artificial graphite or natural graphite as the negative material and matching the corresponding ceramic diaphragm, high-voltage electrolyte, adhesive and conducting agent. The lithium ion battery not only has high energy density and high discharging platform, but also is good in chemical performance and safety performance and is applicable to the commercialized mass production.

The invention discloses a high-speed hot stamping gum used for holographic positioning electrochemical aluminium and the preparation method. The gum prepared through the formulation and the method of the invention can achieve good adhesive effect under the appropriate temperature and pressure, and the appropriate release coating is added, thus the holographic image information of the holographic electrochemical aluminium can be stripped and cemented on the surface of the scalded object at the high speed. The fragileness of the gum is moderate, therefore, the trimming performance of the holographic image is good in the hot stamping process, the gum is particularly applied to high-speed hot stamping on the surface of the sheet paper and the printing ink with which the density and the hardness are big, the surface energy is low, the surface wettability is poor, and the general coating liquor is difficult to be transferred and cemented on.

The invention discloses a functional nutrition fertilizer, which comprises the following raw materials in parts by weight: 200-500 parts of organic wastes, 20-60 parts of grass carbon, 60-120 parts of livestock manure, 200-600 parts of rice washing water, 50-100 parts of seaweed mud, 10-50 parts of EM bacteria agent, 1-3 parts of ferrous sulfate, 1-3 parts of copper sulfate, 1-3 parts of zinc sulfate, 0.5-2 parts of manganese sulfate, 0.5-3 parts of ammonium molybdate, 0.3-2 parts of sodium tetraborate, 0.3-3 parts of strontium nitrate, 0.5-1 parts of selenium dioxide, 2-6 parts of magnesium sulfate, 3-8 parts of potassium chloride, 2-8 parts of calcium carbonate, 3-10 parts of bentonite, 5-10 parts of urea, 10-50 parts of traditional Chinese medicine extract, and 10-30 parts of traditional Chinese medicine residue fermented product. According to the functional nutrition fertilizer, the nutrition components are complete and balanced, the disease and insect resistance capacity of soil can be enhanced, the fertilizer efficiency of soil can be increased, and the functional nutrition fertilizer has no environment pollution. The invention further discloses a preparation method of the functional nutrition fertilizer.

The invention discloses a single-component water-cured polyurethane waterproof coating. The single-component coating is a NCO group terminated prepolymer obtained by the reaction of polyether polyol and polyisocyanate after the polyether polyol is hydrated in vacuum; and the weight ratio of the polyether polyol to the polyisocyanate is (2-10): 1. The coating is ecological and environment-friendly, has excellent mechanical property, good high and low temperature resistance and good solvent resistance and corrosion resistance, can be constructed on moist basal planes, does not affect adhesive property, and has high cost performance, low specific weight, low consumption in unit area and low comprehensive manufacturing cost.

The invention relates to a hand-care disposable disinfection gel and a preparation method thereof. The hand-care disposable disinfection gel comprises ethanol, a bactericide, a cosolvent, a thickener, an emollient, essence and a PH regulator, wherein the essence is used as a carrier to cover pungent odor of ethanol. The hand-care disposable disinfection gel has the advantages of being bactericidal, washing-free, not sticky and greasy, and comfortable in smell, and caring hands. The preparation method comprises the following steps: the thickener swells in purified water fully to prepare a liquid A; meanwhile, the bactericide and the cosolvent are added in ethanol to be mixed uniformly to prepare a liquid B; then, the liquid B is poured into the liquid A; the emollient and the essence are poured in the liquid A, after purified water is supplemented to be sufficient, the PH regulator is added to regulate the PH value to 6.0-8.0, and the uniform mixing is performed.

The present invention relates to a method for preparing cerium oxide coated silica particles and cerium oxide silica particles obtainable by the method. The invention further relates to cerium oxide coated silica particles and the use thereof for polishing.

The invention provides a piece of novel sewing-free hot melt adhesive TPU-PU leather, and a preparation method thereof. The TPU-PU leather comprises release paper, a hot melt adhesive film, a TPU film and a dry-type PU film, wherein the release paper comprises a paper bottom layer, an adhesive layer, a plastic layer, a transition layer, and a release layer; a hot melt adhesive raw material is composed of polyester polyol, diisocyanate, polyether polyol, and a plurality of additives; a TPU raw material is composed of polymer polybasic alcohol, 1,4-cyclohexane-diisocyanate, a chain extender and a plurality of functional additives; a PU raw material is composed of polyester dibasic alcohol, straight chain diol, isocyanate, TDI trimer, dimethyl formamide, butanone, black sand, and a plurality of functional addictives. Through the adoption of the preparation method, innovations are conducted on the raw material components of the release paper, the hot melt adhesive, the TPU film and the PU film; the manufactured sewing-free TPU-PU leather has the technical advantages of firmness in adhesion, durability, environment-friendly materials, no invisible harm to a human body, and the like.

The invention discloses a green nursery stock planting substrate multifunctional additive, which is characterized in that the additive comprises the following components in weight portion: 1)150 to 200 portions of vegetable carbide; 2) 5 to 10 portions of polyacrylamide type high absorbent resin;3) 0.5 to 1 portion of inorganic fertilizer or compound fertilizer containing nitrogen, phosphorous, kalium elements and the like; 4) 0.05 to 0.1 portion of encapsulated type slow / controlled release fertilizer; 5) 10 to 20 portions of organic fertilizer; and 6) 0.03 to 0.05 portion of compound microbial inoculum comprising photosynthetic bacteria, actinomycete, microzyme, lactobacillus, rhizobium, bacillus and thiobacillus. By the additive, the planting survival rate of nursery stock is more than 98 percent, and the additive also has the advantages of quick seedling recovery, vigorous rooting, vigorous growth and obvious effects.

The powerful adhesive includes neoprene, grafting monomer, thickener, dispersant, adhesion promoter, catalyst, antioxidant, solvent, stuffing, etc. The present invention also discloses the preparation process of the adhesive, and the preparation includes introducing grafting monomer to neoprene molecule chain to raise the adhesion strength, selecting proper adhesion promoting resin to increase the initial adhesion force, and adopting mixed solvent to form high adhering performance. The adhesive has high solid content and excellent environment protecting performance, and has also excellent antiageing performance, high resistance to heat, oil, chemical and corrosion, high weather resistance, good mildew-proof performance, antibiotic performance, etc. and may be used for adhering timber, concrete, rubber, metal, gypsum board, brick and other building material.

The invention discloses a remediation method of organic contaminant-heavy metal compound contaminated soil. The remediation method comprises the following steps: adding persulfate into organic matter-heavy metal compound contaminated soil, and on the basis of effective oxidative degradation of organic contaminant, further using iron-based biochar for passivating heavy metals after playing an activating effect so as to achieve effective remediation of the organic matter-heavy metal compound contaminated soil. Compared with the method for remedying contaminated soil with single contamination by using the biochar or the persulfate, the remediation method provided by the invention has the advantages as follows: two methods are combined for remedying organic matter-heavy metal compound contamination, the persulfate is used for oxidizing organic matters and can fully mineralize the organic matters; for heavy metal contaminated soil, the persulfate can oxidize the heavy metals, and reduces the pH of the soil to cause an increase in the concentration of effective-state metal; the biochar fixes the heavy metals to the surface through adsorption, so that the bioavailability of the heavy metals is reduced.

The invention provides high-resilience antibacterial medical polyvinyl chloride (PVC) plastic and a preparation method thereof. The high-resilience antibacterial medical PVC plastic comprises, by weight, 100 parts of ultra-high molecular weight PVC resin, 40-80 parts of a plasticizer, 10-60 parts of an elastomer, 5-20 parts of an auxiliary plasticizer and 0.5-5 parts of a heat stabilizer. The invention relates to the high-resilience antibacterial medical PVC plastic which has good physical properties, chemical performances and biological properties, satisfies GB15593-1995 blood (liquid) transfusion device flexible PVC plastic related requirements and is medical PVC plastic with excellent resilience and antibacterial and bacteriostatic effects, and the preparation method thereof. The PVC plastic has the characteristics of excellent antibacterial property, bacteriostasis and resilience, shortens an ethylene oxide disinfection period and improves disinfection efficiency.

A memorial object cast in a mold and formed of a concrete mix having up to about 50% sand, up to about 25% aggregate, up to about 25% cement, and water. In one embodiment of the invention cremation ash is incorporated in the mix up to about 60% of the mix, with the percentage of at least one of the other ingredients, preferably sand and / or aggregate, being reduced corresponding to the amount of cremation ash added. In another embodiment, a cavity is formed in the object for receiving and holding a separate container holding cremation ashes. Various additives can be added to the mix, either alone or in combination, including an accelerator, an air entrainer, a plasticizer, and glass fibers. One or more of a motion detector, voice-activated recording, water effects and / or an illumination device can be mounted in the object.

The invention discloses a preparation method of a hollow fabric with radial elastic shrinkage and relates to the preparation method of the hollow fabric. The object of the invention is to solve the problem that elastic hollow fabric available in the market does not meet the requirement of thin diameter and longitudinal elasticity and very large radial elasticity when being used in a specific task, has poor strength of bearing accidental drawing and poor wearability, as well as poor dimensional stability, and especially poor radial elasticity. The method comprises the preparation work of warp yarns, which includes selecting fine denier 75-200D aramid fiber fibers, 100-300D PBO (p-phenylene-2,6- benzobisoxazazole fiber) fibers or aramid fibers and PBO combined filament yarns as warp yarns; preparation work of weft yarns; directly winding of the weft yarns to form a pirn with a size same as that of a shuttle of a shuttle loom; and a determining and weaving process of metric portie. The hollow fabric prepared by the preparation method provided by the invention has excellent radial elastic recovery, and also the characteristics of superstrong resistance to longitudinal stretching force and wear resistance and corrosion resistance. The method is used for preparing elastic hollow fabrics.

The invention provides a water-base cement which consists of a main adhesion agent, an auxiliary adhesion agent and a defoaming agent which are mixed according to the weight ratio of 20-30:1-3:1-5, wherein, the main adhesion agent is a mixed liquor prepared by one or a plurality of polyethylene glycol oxide, sodium carboxymethyl cellulose or polyvinyl alcohol with de-ionized water, and the solid content thereof is between 1 percent and 10 percent; the auxiliary adhesion agent is the mixed liquor prepared by one or two of butadiene styrene rubber or polyfluortetraethylene with the de-ionized water, and the solid content thereof is between 30 percent and 70 percent; the defoaming agent is one or a plurality of ethanol, glycol or propanediol which are mixed for use. The water-base cement has low cost, is innoxious and environment-friendly. The invention also provides a lithium battery which uses the water-base cement and a manufacturing method for the lithium battery.

The invention relates to a hydroxy acrylic resin dispersoid and a waterborne coating prepared from the same. Resin is obtained by two-step polymerization, amine is added to perform neutralization, andwater is added to disperse the resin to obtain the stably stored hydroxy acrylic resin dispersoid with a core-shell structure. Two steps include: first, preparing a hydrophobic portion by free radical solution polymerization; second, preparing a hydrophilic portion by free radical solution polymerization. The hydroxy acrylic resin dispersoid has the core-shell layered structure and has the advantages of high solid content, low viscosity and the like. The two-component waterborne acrylic coating prepared by the method can combine the advantages of an acrylic coating and a polyurethane coating,has excellent physical performance, chemical performance and appearance performance, has the advantages of high paint film crosslinking density and hardness, good toughness and chemical medium resistance, high drying speed, capability of drying at room temperature and the like, and is widely applied to priming paint, finishing paint and priming and finishing combined paint of various engineeringmachinery and automobiles.

The invention provides an electrode current collector material of a lithium ion battery and a method for preparing the material. The method comprises the following steps of: coating a carbon layer on the surface of a copper foil or an aluminum foil, wherein the thickness of the coated carbon layer is 0.003-0.015mm; and depositing the carbon layer on the surface of the copper foil or the aluminum foil by utilizing a physical vapor deposition method, and then carrying out thermal treatment. While ensuring the conductive property of the material as a current collector, the material improves the chemical property of easy oxidization of the foil in the working process of the battery, enhances the corrosion resisting property of the foil, and can effectively prevent a metal dendritic crystal produced by the lithium ion battery in the working process due to reaction, increase the safety performance of the battery, reduce the internal resistance of the battery and effectively prolong the service life of the battery. The process has the advantages of low temperature, less distortion and damage on the material, low energy consumption, less pollution and lower cost.

The invention discloses a lithium-sulfur secondary battery system. The system comprises a positive electrode, a negative electrode and electrolyte, wherein an active substance of the positive electrode is a carbon-sulfur composite material, the negative electrode adopts a metal lithium plate, the electrolyte is high-salinity non-aqueous electrolyte, and the high-salinity non-aqueous electrolyte comprises lithium salt, sodium salt or lithium-sodium mixed salt and non-aqueous organic solvent; and the mol ratio of the lithium salt or the lithium-sodium mixed salt and the non-aqueous organic solvent is 2 to 10 mol / L. The lithium-sulfur secondary battery system has the following remarkable advantages that since the electrolyte system can effectively prevent multi-sulfur ions of the lithium-sulfur battery from being dissolved in the electrolyte in the charging and discharging processes, the multi-sulfur ions which are dissolved in the electrolyte can be prevented from producing a shuttle effect at the last stage of the charging, the over-charge phenomenon can be prevented, and the coulombic efficiency can be improved to be more than 99 percent. Therefore, the cycling performance of the battery also can be greatly improved.

The invention relates to a seeding medium made of vinasse methane-sludge and a preparation method thereof, not only solving the problem of environment contamination caused by vinasse methane-sludge, but also effectively utilizing vinasse methane-sludge. The seeding medium comprises fresh sludge containing 90 percent of water after methane generated from vinasse in a methane tank, accessories, ferment strain I and ferment strain II, wherein the accessories comprise grass peat, vermiculite and perlite; the ferment strain I comprises saccharomycetes, lactobacillus, high-temperature actinomycetes and bacillus; and the ferment strain II comprises photosynthetic bacteria, lactobacillus, bacillus, saccharomycetes, actinomycetes and terrestrial cyanobacteria. The preparation method comprises the following steps of preparing fresh sludge, dehydrating, adding the ferment strain I for fermentation, adding the ferment strain II for secondary fermentation, air drying, adding accessories, crushing, screening and packing. The vinasse methane-sludge contains 40 to 50 percent of organic matter and 4.3 percent of available nitrogen (N), phosphorus (P) and kalium (K). The seeding medium made of vinasse methane-sludge has better hydrophilicity, and seeding can be carried out after loading the dry seeding medium and spraying water, thus saving both labor and time.

The invention relates to a solder auxiliary soldering method, in particular to a graphene-enhanced Al-based composite solder auxiliary soldering method. The method solves the problems that existing graphene is poor in aluminum base enhancing effect and poor in dispersibility. The method comprises the steps that an oxidized graphene suspension and an aluminum solder suspension are mixed, dried and then placed into a plasma enhanced chemical vapor deposition vacuum device for reduction treatment, then, the mixture is pressed into foils, the graphene / aluminum-based solder foils are placed between to-be-soldered faces of metal to be soldered for vacuum soldering, and the graphene-enhanced Al-based composite solder auxiliary soldering method is completed. The method is used for graphene-enhanced Al-based composite solder auxiliary soldering.

The invention relates to a biochar-based soil modifier, and aims at providing a Baijiang soil modifier which is low in cost, good in modification effect, economical and environment-friendly, has the functions of improving the water retention capability and the air permeability of soil, controlling slow release of fertilizers, relieving soil acidification and the like, and simultaneously, can be blended with organic and inorganic fertilizers. The soil modifier comprises biomass charcoal which is obtained by performing thermal cracking and charring on a biomass charcoal raw material under a limited-oxygen condition; and the biomass charcoal is applied through deep tillage to modify the quality of poor Baijiang soil.

The invention discloses a wear-resistant intake valve and a preparation method thereof. The intake valve adopts the following alloying constituents by weight percent: 0.32-0.40 percent of C, 0.17-0.27 percent of Si, 0.5-1.2 percent of Mo, 0.50-0.80 percent of Mn, 0.2-0.5 percent of Nb, 0.80-1.10 percent of Cr, 0.50-1.0 percent of W, no more than 0.030 percent of Ni, no more than 0.015 percent of S, no more than 0.010 percent of Cu and the balance of Fe. The intake valve is processed by the processes of surface nanocrystallization, low-temperature nitridation, build-up welding of tungsten zirconium alloy and the like and has the advantages of high surface strength and rigidity, good wear-resisting property and long service life.

The invention discloses an air inlet valve and a manufacturing method thereof. Alloy for manufacturing the air inlet valve comprises the following components in percentage by weight: 0.32-0.40% of C, 0.17-0.37% of Si, 2.5-3.5% of Mo, 0.50-0.80% of Mn, 0.80-1.10% of Cr, 0.50-1.0% of W, less than or equal to 0.030% of Ni, less than or equal to 0.015 of P, less than or equal to 0.015 of S, less than or equal to 0.010% of Cu and the balance of Fe. The air inlet valve is manufactured by the technologies such as surface nanocrystallization, low-temperature nitriding and surfacing of tungsten-zirconium alloy and the like. The air inlet valve has high surface strength, high hardness, good abrasion performance and long service life.