34 results about "Diacetone alcohol" patented technology

This invention provides a pesticide synergist, its preparation method, and its application, belonging to the field of pesticide adjuvants. The pesticide synergist provided by this invention comprises, by weight percentage, 3.5-4.5% lauric acid, 5.5-6.5% diacetone alcohol, 10-15% emulsifier, and 74-80% solubilizer. The pesticide synergist provided by this invention is environmentally friendly, can improve the contact and adhesion between the active ingredient of the pesticide and its application site, improve the efficiency of pesticide use, and can still maintain high efficacy while reducing the dosage of herbicides, insecticides, and fungicides. Ultimately, it reduces environmental pollution, increases crop yield, lowers costs, and increases profits.

The application discloses a spin coating dispersant for grain boundary diffusion of cerium-rich neodymium-iron-boron magnet and a use method, and belongs to the technical field of neodymium-iron-boron magnet. In view of the selection of the dispersant when rare earth elements are coated by the spin coating method in the process of the grain boundary diffusion of the cerium-rich neodymium-iron-boron magnet, the application provides a suitable spin coating dispersant, which can maximally improve the magnetism of the cerium-rich neodymium-iron-boron magnet under the premise that the magnet and the rare earth elements have the same weight, thereby reducing the total amount of the rare earth elements used in the grain boundary diffusion and reducing the cost. The spin coating dispersant is composed of polyvinyl alcohol and diacetone alcohol as a cosolvent in different mass ratios. Through reasonable compounding of the polyvinyl alcohol and the cosolvent, the surface tension of the dispersion system can be effectively reduced, the wetting capacity of the dispersant to the dispersion source can be enhanced, and the diffusion source can be uniformly dispersed in the dispersant through the steric hindrance effect, so that a stable suspension is formed, and the uniformity of the grain boundary diffusion is remarkably improved.

This adhesive composition includes: an adhesive solution which comprises a dilution solvent and an adhesive component including one or more components selected from a silane coupling agent, an organic titanate compound, an aluminate-based coupling agent, and a zirconate-based coupling agent; and a slow-volatile solvent which is added separately from the adhesive solution, can dissolve the adhesive components therein, and has a vapor pressure at 20°C of 2.33 kPa or less. The slow-volatile solvent includes one or more components selected from methyl isobutyl ketone, ethylene glycol, diacetone alcohol, and ethyl cellosolve.

The invention discloses ink for testing a semiconductor chip and a production method of the ink. The ink for testing the semiconductor chip comprises the following raw materials in percentage: 20-30% of phenoxy resin particles, 55-70% of a diacetone alcohol mixed solvent, 5-10% of a coloring agent and 5% of other additives. According to the ink prepared by the invention, the adhesion performance and the anti-flushing performance are greatly improved, in addition, the effective time is greatly prolonged, the wall hanging condition is also improved, and the utilization rate of a single ink tube is increased.

The present invention relates to a purification process of high purity isopropyl alcohol for semiconductor cleaning processes, comprising the step of removing diacetone alcohol, boric acid triisopropyl ester and metal impurities by means of a distillation process after removing diacetone alcohol in isopropyl alcohol by an adsorption process.

The present invention relates to an impregnation liquid comprising diacetone alcohol in an amount of from 20% to 50% by weight; a glycerol trioleate in an amount of from 20% by weight to 50% by weight; castor oil in an amount of 10 wt% to 40 wt%; acetone in an amount of 3 wt% to 5 wt%; and at least one sulfonate or ester in an amount of from 0 wt% to 1.5 wt%. The invention also relates to a method for treating the surface of an iron component, comprising the step of impregnating with such an impregnating liquid; and the obtained treated component.

The present invention discloses a continuous reactive distillation equipment for synthesizing diacetone alcohol, which comprises a distillation column, an opening and closing mechanism, a condensation mechanism and a rotating mechanism. By setting the opening and closing mechanism, without affecting the operating pressure inside the distillation column, the gas-phase flow is adjusted to extend the residence time of propanol in the reaction section, thereby improving the conversion rate to ensure that the propanol raw material reacts fully to increase the output of the equipment; by setting the condensation mechanism, the discharge path of the by-product water is increased, and the reflux of water is further reduced to reduce its interference with the reaction process, while effectively improving the product purity of diacetone alcohol; by setting the rotating mechanism, coaxial reverse rotation between the reaction section and the reboiler is achieved. While ensuring the uniform distribution of the liquid phase during the reflux of propanol, the liquid phase mixing is promoted by stirring to further improve the separation efficiency of diacetone alcohol and water, thereby reducing its residence time in the high-temperature region to reduce the occurrence of side reactions.

The invention discloses a polyvinylidene fluoride hydrophilic microfiltration membrane, which comprises a membrane casting solution, and the membrane casting solution is prepared from the following raw material components: 5 to 20 weight percent of polyvinylidene fluoride (PVDF) powder, 0.1 to 1.0 weight percent of hydrophilic pore-foaming agent, 0.1 to 0.5 weight percent of water-soluble additive, 5 to 20 weight percent of oxygen-containing solvent and the balance of polar solvent, the water-soluble additive is one or more than two of polyethyleneimine (PEI), sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (LAS) and tannic acid (TA); the oxygen-containing solvent is an alcohol ether oxygen-containing solvent and comprises but is not limited to one or more than two of ethylene glycol monomethyl ether (EGME), ethylene glycol monobutyl ether (BCS), diacetone alcohol (DAA), dipropylene glycol methyl ether (DPM) and propylene glycol butyl ether (PNB). By adding the water-soluble additive and the oxygen-containing solvent into the PVDF membrane casting solution, dissolution and dispersion of solute molecules in the membrane casting solution are promoted, and interaction between hydrophilic components and a PVDF substrate is enhanced, so that the membrane forming leveling property and the hydrophilic effect stability of the PVDF hydrophilic microfiltration membrane are improved.

The invention discloses a waterproof moisture-permeable composite structure membrane based on mixed solvent regulation and control and a preparation method, and belongs to the technical field of materials. The preparation method of the waterproof moisture-permeable composite structure membrane comprises the following steps: carrying out electrostatic spraying on a polyurethane nanofiber membrane base material with a low-surface-energy polyurethane spraying solution, so as to obtain the waterproof moisture-permeable composite structure membrane, wherein a solvent used by the polyurethane spraying solution is formed by mixing a solvent used by the polyurethane spinning solution and diacetone alcohol; according to the mixed solvent method, a polyurethane fiber base material is swelled, molecular chain diffusion and entanglement between the base material and an electrostatic spraying product interface are promoted, so that the bonding force between the composite structure interfaces is improved, and a wafer and cylinder multi-scale composite structure is innovatively formed on a polyurethane nanofiber membrane; the wear resistance, stripping resistance and overall durability of the composite structure layer are improved; the lyophobic performance of the prepared waterproof moisture-permeable composite structure film is further improved, the durability is improved, and therefore the waterproof moisture-permeable composite structure film can be better and practically applied to the field of medical and defense protection.

An impregnation liquid comprises diacetone alcohol, in a proportion of between 20 wt. % and 50 wt. %, glycerol trioleate, in a proportion of between 20 wt. % and 50 wt. %, castor oil, in a proportion of between 10 wt. % and 40 wt. %, acetone, in a proportion of between 3 wt. % and 5 wt. %, and at least one sulfonate, in a proportion of between 0 wt. % and 1.5 wt. %. A method for surface treatment of a ferrous part includes an impregnation step by such an impregnation liquid, and the treated part obtained.

The invention discloses a micro-fine-particle lepidolite reinforced recovery collecting agent and application of the micro-fine-particle lepidolite reinforced recovery collecting agent. The collecting agent is composed of sodium lauryl sulfate, sulfonated polyacrylamide, hexadecene amine, nitrilotriacetic acid and diacetone alcohol according to a specific proportion. According to the collecting agent, the anionic surfactant is used as a main component, the flocculation and chelation effects of multiple functional groups are utilized, the flotation problem of micro-fine particle lepidolite is solved, the surface lipophilicity of minerals is enhanced, and the flotation efficiency is improved. The collecting agent provided by the invention can efficiently recover the micro-fine particle lepidolite, and provides resource guarantee for the new energy industry.

The invention discloses continuous reaction rectification equipment for synthesizing diacetone alcohol. The continuous reaction rectification equipment comprises a rectification tower, an opening and closing mechanism, a condensation mechanism and a rotating mechanism, by arranging the opening and closing mechanism, on the premise that the operation pressure in the rectifying tower is not influenced, the retention time of propyl alcohol in a reaction section is prolonged by adjusting gas phase flow, so that the conversion rate is increased, the sufficient reaction of propyl alcohol raw materials is ensured, and the yield of the device is increased; the condensation mechanism is arranged, so that the discharge path of by-product water is increased, the reflux of water is further reduced, the interference of water on the reaction process is reduced, and meanwhile, the product purity of diacetone alcohol is effectively improved; through the arrangement of the rotating mechanism, coaxial inversion between the reaction section and the reboiler is realized, and liquid phase mixing is promoted through stirring to further improve the separation efficiency of diacetone alcohol and water while uniform distribution of a liquid phase during backflow of propyl alcohol is ensured, so that the retention time of diacetone alcohol in a high-temperature area is shortened to reduce the occurrence of side reactions.

The application discloses an ice flower effect photocuring paint, which comprises a film forming resin system and a composite diluent; the film forming resin system is composed of acrylic resin A 10-15 parts, acrylic resin B 20-25 parts, acrylic resin C 30 parts, ethyl acetate 14.5 parts, a photoinitiator 15-25 parts and a leveling agent 0.5 part; the composite diluent is composed of butyl acetate 30-35 parts, ethyl acetate 20-29 parts, propylene glycol methyl ether 10-15 parts, diacetone alcohol 11-15 parts and diisobutyl ketone 15-20 parts; the paint can be applied to plastic and other materials which are not resistant to high temperature by low preheating temperature, the curing temperature is low temperature of 55-65 DEG C, the UVA low energy is suitable for more types of materials, the film forming blooming is stable, and more market demands are met.

The utility model discloses a diacetone alcohol synthesis reaction heat recycling device, which relates to the technical field of diacetone alcohol synthesis and comprises a first heat conduction pipe wound on a feeding pipe of a first reboiler. One end of the first heat conduction pipe is communicated with the liquid outlet end of the total condenser through a first liquid inlet pipe, and the other end of the first heat conduction pipe is communicated with the liquid inlet end of the refrigerator through a first liquid outlet pipe; the second heat conduction pipe is wound on the outer wall of a pipe fitting for connecting the reactor and the reactive distillation tower, one end of the second heat conduction pipe is communicated with the liquid outlet end of the cooler through a second liquid inlet pipe, and the other end of the second heat conduction pipe is communicated with the liquid inlet end of the refrigerator through a second liquid outlet pipe; the third heat conduction pipe is wound on the feeding pipe of the second reboiler, one end of the third heat conduction pipe is communicated with the liquid outlet end of the condenser through a third liquid inlet pipe, and the other end of the third heat conduction pipe is communicated with the liquid inlet end of the refrigerator through a third liquid outlet pipe; the device has the advantages of being convenient to use, reducing energy consumption and production cost and the like.

The application discloses a two-component water-based polyurethane finish and a preparation method thereof. The two-component water-based polyurethane finish comprises an A component and a B component. The A component comprises the following components in the following proportions by weight: 40-70 parts of a water-based hydroxyl acrylic acid dispersion, 5-12 parts of an activation period lengthening agent, 1-4 parts of a light stabilizer, 0.2-1 part of a dispersing agent, 0.5-2.5 parts of an anti-bubble assistant and 0.05-0.4 parts of a pH regulator. The B component comprises the following components in the following proportions by weight: 40-70 parts of a polyisocyanate curing agent and 30-60 parts of a solvent. The activation period lengthening agent is a mixture of diacetone alcohol and ethylene glycol butyl ether acetate in a weight ratio of 2:(1-3). The two-component water-based polyurethane finish of the application reduces the reaction speed of the A component and the B component after mixing by using the diacetone alcohol and the ethylene glycol butyl ether acetate in specific amounts and weight ratios, and prolongs the activation period of the two-component water-based polyurethane finish.

This application discloses a method for preparing diacetone alcohol by acetone condensation, comprising the following steps: in a reactor, acetone is contacted with a catalyst, stirred, and reacted to obtain diacetone alcohol; the catalyst is selected from a molecular sieve treated with ammonia; the molecular sieve is selected from at least one of MCM-41 molecular sieve, MCM-48 molecular sieve, and SBA-15 molecular sieve. This method has advantages such as high acetone conversion rate and diacetone alcohol yield, good catalyst recycling performance, simple post-reaction treatment, and no waste salt or wastewater generated.

The invention discloses a spin-coating dispersing agent for grain boundary diffusion of a cerium-rich neodymium-iron-boron magnet and a using method, and belongs to the technical field of neodymium-iron-boron magnets. In order to solve the problem of selection of dispersants when rare earth elements are coated with a spin-coating method in the grain boundary diffusion cerium-rich neodymium-iron-boron magnet process, the invention provides a proper spin-coating dispersant which can improve the magnetic performance of cerium-rich neodymium-iron-boron to the maximum extent on the premise that the magnet and the rare earth elements are the same in weight, and the application range of the cerium-rich neodymium-iron-boron magnet is widened. Therefore, the total amount of rare earth elements for grain boundary diffusion is reduced, and cost is reduced. The spin-coating dispersant is composed of a polymeric dispersant polyvinyl alcohol and a cosolvent diacetone alcohol in different mass ratios, through reasonable compounding of the polymeric dispersant and the cosolvent, the surface tension of a dispersion system can be effectively reduced, the wetting ability of the dispersant to a dispersion source is enhanced, and through the steric hindrance effect, the surface tension of the dispersion system can be effectively reduced. And the diffusion source is uniformly dispersed in the dispersing agent to form a stable suspension, so that the uniformity of grain boundary diffusion is remarkably improved.

The invention discloses a diacetone alcohol production system which is characterized in that an outlet of a raw material tank is communicated with a feed port at the bottom of a fixed bed reactor through a raw material conveying pipeline, a discharge port at the top of the fixed bed reactor is communicated with a gas-liquid separation tank, and a liquid phase outlet of the gas-liquid separation tank is communicated with a feed port of a falling film evaporator; a gas-phase outlet of the gas-liquid separation tank flows back to the raw material tank through a first backflow pipeline, a gas-phase outlet of the falling-film evaporator flows back to the raw material tank through a second backflow pipeline, an outlet of the falling-film evaporator is connected with an inlet of the dividing wall rectifying tower through a pipeline, and the upper portion of the dividing wall rectifying tower is divided into a left area and a right area by a center partition plate. An inlet of the dividing wall rectifying tower is positioned in the middle of the acetone area; and a gas-phase discharge hole is formed in the side wall close to the lower part of the dividing wall rectifying tower. According to the method, most AC is recycled by adopting simple evaporation equipment, and the method has the characteristics of simple process, remarkable separation effect and lower energy consumption.

The invention discloses a continuous reaction process for producing diacetone alcohol, and relates to the technical field of chemical synthesis. The method comprises the following steps: step 1, condensation reaction: adding a composite catalyst into a reactor, then injecting acetone into the reactor through a feeding pipe, reacting and cooling to obtain a reaction mixture; step 2, primary rectification: transferring the reaction mixture into a rectification device, carrying out primary rectification, and collecting fractions of diacetone alcohol; 3, secondary rectification: carrying out secondary rectification on the diacetone alcohol fraction collected in the step 2, and collecting a diacetone alcohol primary product; and 4, tertiary rectification: carrying out tertiary rectification on the diacetone alcohol primary product collected in the step 3 to obtain diacetone alcohol. The method has the beneficial effects that the diacetone alcohol is prepared through an efficient continuous reaction process; moreover, through an effective modification process, the performance of the catalyst is improved, and the service life of the catalyst is also prolonged while the conversion rate of diacetone alcohol is improved.

The present invention relates to the field of synthesis of 2-methyl-3-butyn-2-ol (hereinafter referred to as methylbutynol), discloses a post-processing refining method of methylbutynol and an application thereof. The post-processing refining method comprises: (1) mixing a methylbutynol reaction mixture with a weakly basic carbonate for quenching, and flashing the obtained quencher; (2) recovering the crude liquid phase product obtained in step (1) with acetone, and rectifying the obtained methylbutynol crude product to obtain a pure methylbutynol. The present invention uses anhydrous weakly basic carbonate as a quenching agent, can reduce additional dehydration operations, shorten the production cycle, and improve production efficiency; can decompose diacetone alcohol into acetone, reduce acetone unit consumption, reduce impurity content, and improve the yield and purity of methylbutynol; can avoid causing diacetone alcohol to be dehydrated to generate mesityl oxide, and reduce the difficulty of rectifying methylbutynol.

The present application relates to a kind of methods for synthesizing corresponding alcohol by electrocatalytic hydrogenation of carbonyl compound, using flow electrolytic cell or split H-type electrolytic cell, adding carbonyl compound in cathode electrolyte, collecting liquid phase alcohol product at reaction output end.The carbonyl compound includes formaldehyde, acetaldehyde, acetone, n-propyl aldehyde, n-butyl aldehyde, n-pentanal, 4-hydroxy-2-butanone, diacetone alcohol, 2-pentanone, cyclobutanone, furfural and other carbonyl-containing compounds.Different types of electrolytic cell are used, and the iron-based electrocatalyst constructed has the characteristics of low cost, high activity and high selectivity.Compared with traditional thermal catalytic technology, the electrocatalytic hydrogenation of carbonyl compound to synthesize corresponding alcohol technology is carried out at room temperature and normal pressure, using water as hydrogen source, which not only reduces energy consumption and production cost, but also is green, safe and efficient, in line with the requirements of green chemical industry.

The utility model relates to the technical field of chemical production environmental protection, and discloses a diacetone alcohol production raffinate recovery device which comprises a recovery assembly, a filter assembly is placed on the upper portion in the recovery assembly, and the filter assembly comprises a primary filter part, an intermediate filter part and an advanced filter part. The primary filtering part, the intermediate filtering part and the high-grade filtering part are sequentially stacked from top to bottom, and the recycling assembly is externally connected with a heating assembly in a sleeving manner; the heating assembly comprises a heating cylinder, one side of the upper portion outside the peripheral surface of the heating cylinder is fixedly connected with an oil inlet piece, and one side surface of the bottom surface of the heating cylinder is fixedly connected with an oil outlet piece. According to the diacetone alcohol production raffinate recovery device, through the arrangement of the filtering assembly and the heating assembly, the problems that when an existing diacetone alcohol production raffinate recovery device is used, impurities in raffinate are not thoroughly separated, the purity of recovered diacetone alcohol is not high, and certain limitation exists in use are solved; or the energy consumption is high in the recovery process, and the production cost is increased.

The invention provides a long-acting corrosion-resistant environment-friendly coiled steel plate and a preparation method of a primer coating of the long-acting corrosion-resistant environment-friendly coiled steel plate and belongs to the technical field of coatings. Comprising a base plate, a primer coating and a finish coating, and the primer coating is prepared from, by mass, 40%-60% of epoxy modified polyester resin, 3%-5% of calcium ion exchange antirust pigment, 3%-5% of organic-inorganic composite antirust agent, 4%-6% of mixed ketone solvent, 3%-4% of aromatic hydrocarbon 100 # solvent, 6%-10% of dispersing agent, 3%-5% of titanium dioxide, 8%-12% of filler, 4%-7% of isocyanate and amino cross-linking agent and 0.2%-0.4% of defoaming agent. The coating is prepared from the following components in percentage by weight: 3-5% of epoxy phosphate, 0.2-0.4% of flatting agent, 3-5% of epoxy phosphate, 0.3-0.5% of phosphoric acid catalyst and the balance of diacetone alcohol. The calcium ion exchange anti-rust pigment and the organic-inorganic composite anti-rust agent are used for replacing a chromium-containing pigment, the GB 30981-2020 environmental protection standard is met, and toxic harm is avoided; through matching of the epoxy modified resin and the auxiliaries, the problems that a traditional coating is prone to cracking if hard and prone to damage if soft are solved, balance of hardness and toughness is achieved, and particularly the water erosion resistance of the bent position is improved.

The present disclosure provides a method of preparing Compound (1): (Formula1), or salt or solvate thereof, the method comprising reacting a composition comprising 4-aminodiphenylamine, or a salt or solvate thereof, with acetone, mesityl oxide, diacetone alcohol, a compound of Formula (I): (Formula I), wherein R1 and R2 are as defined in the specification, or a combination thereof; in the presence of a catalyst and, optionally, a solvent; at a reaction temperature of from about 50 °C to about 180 °C. The present disclosure also provides compositions comprising Compound (1), or a salt or solvate thereof, prepared by the methods disclosed herein.

The invention discloses a method and a system for preparing beta-hydroxy-beta-methylbutyric acid and salts thereof, and the method specifically comprises the following steps: reacting diacetone alcohol with an oxidant solution to obtain a mixed solution, adjusting the pH value of the mixed solution to be less than or equal to 2, carrying out liquid separation treatment, and collecting a reaction solution containing beta-hydroxy-beta-methylbutyric acid to obtain the beta-hydroxy-beta-methylbutyric acid. Controlling the pH value of the reaction liquid to be less than or equal to 2, and performing electrodialysis treatment on the reaction liquid to obtain beta-hydroxy-beta-methylbutyric acid with relatively high purity. And mixing the prepared beta-hydroxy-beta-methylbutyric acid with at least one metal cation source reagent to obtain the salt of the beta-hydroxy-beta-methylbutyric acid. The preparation method provided by the invention has the characteristics of simple process, easy operation, high automation degree, high product yield and purity, easy realization of industrial production and the like, the purity of the prepared product can reach 98%, the recovery rate reaches 95%, multiple extraction processes or reduced pressure distillation treatment are avoided, and the method is suitable for industrial production. And the use of organic solvents and flammable and explosive reagents is reduced, so that the method is safer and more environment-friendly.

An impregnation liquid comprising 20 to 50% by mass of diacetone alcohol, 20 to 50% by mass of glycerol trioleate, 10 to 40% by mass of castor oil, 3 to 5% by mass of acetone, and 0 to 1.5% by mass of at least one sulfonate. A surface treatment method for an iron part, comprising an impregnation step with the impregnation liquid, and a treated part obtained thereby.

The invention discloses a diacetone alcohol continuous production system and a process thereof, and relates to the technical field of diacetone alcohol production, two first partition plates are arranged in a distillation tower in parallel; the two second partition plates are arranged in the distillation tower in parallel; the first reaction box is positioned between the two first partition plates; the second reaction box is positioned between the first partition plate and the second partition plate; the third reaction box is positioned in the feeding cavity; the stripping box is located in the reboiler cavity, and fourth steam through holes are formed in the positions, corresponding to the second through holes, of the upper end wall and the lower end wall of the stripping box respectively; the device has the advantages that the device is convenient to use, and the sufficient reaction time can be effectively prolonged, so that the production efficiency is improved, and the like.

This invention belongs to the field of coating technology and discloses a laser-etchable PU elastic paint, its preparation method, and its application. The paint includes components A, B, and C. Component A is prepared from modified flexible polyester and polycarbonate resin. Component B is prepared from aliphatic polyisocyanate and butyl acetate. Component C is prepared from ethyl acetate, butyl acetate, and diacetone alcohol. The modified flexible polyester is prepared from polyester polyol and 2-hydroxy-4-methoxybenzophenone. This invention provides a laser-etchable PU elastic paint, its preparation method, and its application. This paint can be applied to the surface of electronic cigarette casings and can be used in conjunction with various color effect primers.

The invention relates to a liquid crystal aligning agent, a liquid crystal alignment film, and a liquid crystal display element. Provided are a liquid crystal aligning agent, a liquid crystal aligning film, and a liquid crystal display element which are capable of suppressing poor coating of an aligning film and non-uniformity of display of a liquid crystal display element due to the influence of a wiring structure or C / H, and which are capable of reducing viscosity while maintaining a resin component and a molecular weight. A liquid crystal aligning agent containing: at least one polymer selected from the group consisting of polyimide precursors and polyimides that are imides thereof; and a solvent containing a solvent A, a solvent B, and a solvent C. Solvent A: is selected from the group consisting of N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, [gamma]-butyrolactone, and dimethylimidazolinone. The solvent B is dipropylene glycol dimethyl ether. Solvent C: selected from the group consisting of diethylene glycol diethyl ether and diacetone alcohol.

In a method for purifying highly pure isopropyl alcohol used in a semiconductor cleaning process, diacetone alcohol present in isopropyl alcohol is removed by an adsorption process, and diacetone alcohol, triisopropyl borate, and metal impurities are removed by a distillation process. The purified isopropyl alcohol may have a purity of has the moisture of 10 ppm or less, the triisopropyl boron compound of 50 ppt or less, and each metal of the metal impurities of 20 ppt or less.