103 results about "Oxoacid" patented technology

The invention discloses a multi-alkyl aromatic alcohol extended block copolymer or oxysalt thereof as well as a synthesis method and application thereof. Molecules of the product contain polyalkyl, aryl, polyoxypropyl / ethyl and various ionic hydrophilic group structures, the product has excellent temperature resistance and salt tolerance and stable chemical properties, the adsorption loss in sandstone is extremely small, any alkaline agent does not need to be added, the crude oil recovery rate can be increased by 40% or above only through a single component at the concentration of 0.3 wt%, and the oil recovery rate can be increased by 30% or above. And the influence of performance degradation of the composite oil-displacing agent in an oil reservoir due to a chromatographic separation effect is avoided.

This proton conductive electrolyte material has a chemical structure which comprises an acidic polymer (2) that contains an oxo acid group represented by -POx(OH)y (wherein x and y are each 1 or more), having a phosphorus atom, and at least one saturated hydrocarbon group in the main chain, and a basic polymer (3) that contains a basic functional group, while having at least one aromatic ring in the main chain, wherein an attractive interaction occurs between the oxo acid group and the basic functional group. This fuel cell is provided with the proton conductive electrolyte material. This method for producing a proton conductive electrolyte material includes: preparing a first solution by means of an acidic polymer and a mixed solvent; preparing a second solution in which a basic polymer is dissolved in a solvent; and preparing a mixed solution in which the first solution and the second solution are mixed. With respect to the preparation of the first or second solution, a mixed solvent which contains an inhibitor that is capable of inhibiting rapid aggregation of the oxo acid group and the basic functional group is prepared.

The invention discloses a method for preparing a scale layer on a secondary side of a steam generator and a test sample piece on the secondary side of the steam generator. The method comprises the following steps: dissolving ferric salt, oxysalt, an acid compound and an organic solvent in deionized water to form a mixed aqueous solution; taking the mixed aqueous solution as a raw material, and depositing a scale layer precursor on a test sample on the secondary side of a steam generator by adopting a hydrothermal method; and heating the scale layer precursor in an inert gas atmosphere so as to form a simulated scale layer on the test sample. According to the method, preparation of the simulated scale layer is completed based on hydrothermal synthesis-high-temperature firing, the ultra-long period of preparing the simulated scale layer through high-temperature and high-pressure corrosion is avoided, rapid preparation of the steam generator secondary side sample sediment simulated scale layer is achieved, and the deposited scale layer growing closer to the actual operation environment can be simulated.

The invention discloses a chlorine-nitrogen co-coordinated monatomic zirconium adsorbent and application thereof in selective defluorination of high-salinity wastewater, and belongs to the technical field of fluorine-containing wastewater treatment. The preparation method comprises the following steps: self-assembling melamine and cyanuric acid to obtain supramolecules, ball-milling the supramolecules and zirconium chloride, and pyrolyzing twice to obtain the chlorine-nitrogen co-coordinated monatomic zirconium adsorbent. According to the adsorbent, strong electrostatic repulsion is applied to oxygen-containing acid radicals through electronegative nitrogen ligands, and strong coordination is applied to fluorine ions through electropositive zirconium atoms, so that selective capture of low-concentration fluorine ions in high-salinity wastewater is realized. Compared with a traditional adsorbent, the prepared adsorbent has the advantages of being high in fluorine removal capacity, high in salt tolerance and the like, can overcome the defects that a conventional chemical precipitation method, a coagulation method and a flocculation method are large in agent dosage, high in hazardous waste yield, high in treatment cost and the like, and has a wide application prospect.

The present application relates to an organic compound, a solar cell and the use thereof. The organic compound is as represented by formula (1) or is an oxyacid salt of the compound as represented by formula (1), wherein Ar1 and Ar2 are each independently selected from an aryl group having 6-30 ring-forming atoms or a heteroaryl group having 5-30 ring-forming atoms; n2 and n3 are each independently selected from any integer from 0 to 10; Q1 is selected from *–(L1)n4-A; Q2-Q3 are each independently selected from H, *–(L1)n4-A, or *–(L2)n5-H, with A being selected from an oxyacid group; and at least one of Q2 and Q3 is selected from *–(L1)n4-A. The organic compound can improve the photoelectric conversion efficiency of a solar cell.

The present invention relates to a process for recovering one or more metal species from a raw material, such as a spent lithium ion battery material, comprising: providing a molten salt comprising at least one metal hydroxide, providing one or more oxyacidity agents, preferably as a reservoir of one or more oxyacidity agents in communication with the molten salt, the oxyacidity of the molten salt is set to an oxyacidity value at which at least one metal substance is dissolved in the molten salt with the one or more oxyacidity agents, and the raw material is brought into contact with the molten salt, at least one of steps b) and c) is performed: b) setting the potential of the molten salt to recover the first metal species as a first metal or a first metal oxide, c) adjusting the oxyacidity of the molten salt with the one or more oxyacidity agents to precipitate the first metal oxide, d) for one or more additional metal species, optionally, at least one of method steps a) and / or method steps b) and c) is performed.

The present invention relates to the use of at least one oxoacid reducing element, and optionally a salt of the oxoacid reducing element, in a molten chloride fuel salt for a molten-salt nuclear fission reactor (MSR). The present invention also relates to a process of nuclear fission within a molten-salt nuclear fission reactor (MSR), said process being characterized in that it is carried out within the MSR reactor, placed in which is an oxoacid reducing element, and optionally a salt of the oxoacid reducing element. The present invention further relates to a molten-salt nuclear fission reactor (MSR) comprising a molten chloride fuel salt, and a mixture comprising the aluminum metal, and its oxidized form, as an oxoacid reducing element, and optionally a salt of the oxoacid reducing element.

The application discloses a phosphate-based dry film lubricating coating and preparation and application thereof. The coating is obtained by curing components with the following mass fractions, wherein the components consist of the following ingredients: phosphate binder 15-18 parts, sulfide 3-5 parts, silver powder 4-6 parts, oxygen-containing acid salt 1.5-3.5 parts, and metal oxide 0.2-0.32 parts, antioxidant 0.6-1.2 parts, and surfactant 0.1-0.2 parts, and the rest is solvent. The application solves the problems of weak adhesion between the existing coating and the substrate, wide temperature range lubrication from room temperature to 800 DEG C, large friction coefficient, short wear life and high cost. The coating has good adhesion to the substrate material, excellent flexibility and impact resistance, is environment-friendly, low-cost and has excellent friction-reducing and wear-resisting performance, has a low friction coefficient from room temperature to 800 DEG C, especially a friction coefficient < 0.16 at 800 DEG C, and has a long wear life.

The invention discloses a preparation method of an oxyacid radical modified graphite-based cathode for electro-catalysis hydrogen peroxide synthesis. An oxyacid (sulfuric acid or phosphoric acid) and nitric acid are compounded to form a mixed acid solution, and the graphite-based electrode is subjected to oxyacid radical modification by using the mixed acid solution. The preparation method of the oxygen-containing acid modified graphite-based electrode is simple and low in cost, does not need harsh conditions such as high temperature and the like, and has great industrial and large-scale production potential; the oxygen-containing acid radical modified graphite-based cathode prepared by an acid treatment method is used for reducing oxygen to produce hydrogen peroxide, the yield of the hydrogen peroxide exceeds 21.79 mg.cm <-2 >. H <-1 > and is increased by about 20 times compared with the yield (1.13 mg.cm <-2 >. H <-1 >) of oxygen oxidation by using unmodified original commercial carbon paper, and meanwhile, the highest selectivity of the hydrogen peroxide is up to 97.5%.

The present application relates to a perovskite cell, a photovoltaic module, a photovoltaic system, an electrical apparatus, and a power generation apparatus. The perovskite cell comprises a hole transport layer, a passivation layer, and a perovskite material layer which are stacked. The passivation layer contains an ammonium salt compound. In the ammonium salt compound, an anionic group comprises a group formed after at least one hydroxyl group in at least one oxyacid-containing group in a compound represented by formula (1) loses hydrogen, and a cationic group comprises a group formed after an amino group in a compound represented by formula (2) gains hydrogen. The perovskite cell has excellent photoelectric conversion efficiency and stability.

This invention discloses a method for preparing ZSM-5 molecular sieves using a microwave-assisted method with desilication solution, comprising the following steps: First, pretreatment of the desilication solution: the desilication solution is mixed with an oxyacid to adjust the pH to 9-11.5, a template agent is added and mixed evenly to obtain an initial gel; Second, preparation of the ZSM-5 molecular sieve: the initial gel obtained in the first step is placed in a microwave synthesizer for aging with high-speed stirring; the aged solution undergoes a crystallization reaction, followed by filtration, washing, drying, and high-temperature calcination to obtain the ZSM-5 molecular sieve. This invention uses desilication solution as a raw material to prepare ZSM-5 molecular sieves, saving material costs and providing a new approach for the high-value utilization of desilication solution. Furthermore, by utilizing microwave-assisted synthesis on the basis of the traditional hydrothermal method, the time cost is effectively shortened.

The invention belongs to the technical field of electrolyzed water, and particularly relates to an electrolyte additive for improving the reaction performance of electrolyzed water, an electrolyte, an electrolyte solution and a method for improving the reaction performance of electrolyzed water. The additive comprises nonmetal oxosalts (sulfate, phosphate, borate, selenate, silicate, carbonate, perchlorate, trifluoroacetate and the like) and an aqueous solution of the nonmetal oxosalts, and is used as an electrolyte additive for water electrolysis reaction with KOH or NaOH as an electrolyte. The invention provides application of oxysalt to improvement of oxygen evolution activity and stability of electrolyzed water. In particular, the device is also suitable for electrolytic reactions carried out at high and low temperatures. Due to the addition of the oxysalt, the oxygen evolution reaction potential is reduced, the charge transfer resistance is reduced, the electron transmission rate is increased, and relatively high chemical reaction kinetics is achieved, so that the reaction activity is favorably improved.

The present invention provides an electrochemical oxygen reduction catalyst having high proton conductivity and high durability. One embodiment of the present invention relates to an electrochemical oxygen reduction catalyst comprising a catalytic metal that has oxygen reduction activity and a modification layer that modifies the catalytic metal, wherein the modification layer contains a nitrogen-containing cyclic organic compound, or a polymer thereof, or a cation thereof, and an unsubstituted oxoacid or an anion thereof. Another embodiment of the present invention relates to a fuel cell comprising at least: a cathode electrode catalyst layer containing the electrochemical oxygen reduction catalyst according to the one embodiment of the present invention; an anode electrode catalyst layer; and an electrolyte membrane disposed between the cathode electrode catalyst layer and the anode electrode catalyst layer. Still another embodiment of the present invention relates to a method for producing the electrochemical oxygen reduction catalyst according to the one embodiment of the present invention, the method including a modification step in which a catalytic metal containing platinum or a platinum alloy, and a modifier containing a nitrogen-containing cyclic organic compound, or a polymer thereof, or a cation thereof, and an unsubstituted oxoacid or an anion thereof are mixed to modify the catalytic metal.

The purpose of the present invention is to provide a technique whereby the decomposition of a surfactant can be greatly suppressed without adding a stabilizer. The problem is solved by a method for suppressing decomposition of a surfactant in a cleaning solution for aluminum or an aluminum alloy, the cleaning solution containing an inorganic acid, iron ions, and 0.1-10 g / L of the surfactant, the cleaning solution having a pH of 2 or less. The method includes a step of adding one or more oxoacid salts selected from the group consisting of monooxygenated acid salts and diooxygenated acid salts to the cleaning solution.

The application discloses an isomerization catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts. The isomerization catalyst comprises a carrier and an active component; the active component is a transition metal oxide, and the transition metal is one or more of Mn, Ir and Cu; the carrier is a composite metal oxide and / or a metal oxyacid salt; the composite metal in the composite metal oxide comprises an element A and an element B; and the metal oxyacid salt comprises a metal cation and a metal oxyacid anion. The isomerization catalyst is used for a gas phase catalytic cis-1-chloro-3,3,3-trifluoropropene isomerization reaction to generate trans-1-chloro-3,3,3-trifluoropropene, has high conversion rate, high selectivity, a service life of more than 1000 hours in continuous use, and excellent anti-coking capacity, thermal stability and anti-poisoning performance.

This invention belongs to the field of oxyacid synthesis technology of phosphorus, specifically relating to a method for producing phosphorous acid. The production method includes: (1) adding a metal precursor, organic ligand, reaction promoter, structure directing agent and swelling resistant agent to a pore-forming agent and heating to react, to obtain a mixture; then mixing the mixture with a polymer monomer, crosslinking agent and initiator to obtain an oil phase for later use; mixing a dispersant with water and removing oxygen to obtain an aqueous phase for later use; (2) mixing the oil phase and the aqueous phase to carry out a crosslinking reaction to obtain a crude product; (3) washing, acidifying and vacuum drying the crude product to obtain a porous polymer carrier; (4) after the porous polymer carrier swells in water, adding phosphorus trichloride to it, carrying out a heat preservation reaction, and post-treatment to obtain phosphorous acid. This invention improves the production efficiency of phosphorous acid while ensuring a high yield of phosphorous acid by preparing a porous polymer carrier and using it as a medium for the hydrolysis of phosphorus trichloride to prepare phosphorous acid.

The present invention relates to a method of adjusting the oxoacidity of a molten metal hydroxide salt, the method comprising the steps of: estimating a target concentration of at least one of H2O, O2—, and OH— in a molten salt of a metal hydroxide; providing an oxoacidity control component; and contacting the oxoacidity control component with the molten salt of a metal hydroxide to adjust the oxoacidity of the molten salt of a metal hydroxide. The method allows better utilisation of the available temperature range for a molten salt of a metal hydroxide by reducing the corrosive nature of the metal hydroxide.

The invention relates to a perovskite cell, a photovoltaic module, a photovoltaic system, a power utilization device and a power generation device. The perovskite cell comprises a hole transport layer, a passivation layer and a perovskite material layer which are arranged in a stacked mode. The passivation layer contains an ammonium salt compound; in the ammonium salt compound, an anion group comprises a group formed after at least one hydroxyl group in at least one oxyacid group in a compound shown in a formula (1) loses hydrogen, and a cation group comprises a group formed after an amino group in a compound shown in a formula (2) obtains hydrogen. The perovskite cell has excellent photoelectric conversion efficiency and stability.

To provide a surface treatment agent exhibiting superior water-repellent and oil-repellent properties as a substitute for fluorine compound-based surface treatment agents.SOLUTION: It has been discovered that incorporation of an adduct (A) of a compound selected from polyalkyleneimine and alkylene polyamine with an aliphatic isocyanate, together with an oxide compound (B) selected from citric acid and oxyacids of phosphorus, enables maintenance of superior water-repellent and oil-repellent properties while preventing coloration.SELECTED DRAWING: None

The invention discloses a liquid-phase ammonia-related molten salt catalyst and application thereof. The liquid-phase ammonia-related molten salt catalyst is in a liquid state formed by heating and melting at least one substance component of metal halide, metal hydroxide or metal oxyacid, and is used for directly performing interface contact catalytic reaction with a gaseous reactant under reaction conditions. The liquid-phase ammonia-related molten salt catalyst has the advantages of low cost, high activity and high stability, and the catalytic efficiency of ammonia decomposition, ammonia synthesis, SCR denitration and other ammonia-related reactions can be improved.

The invention belongs to the technical field of hydrates, and particularly relates to a method for removing crystal water of an inorganic hydrate at low temperature and simultaneously realizing structural transformation to obtain a stable anhydride. The preparation method comprises the following steps: mixing inorganic hydrate and acid liquor to obtain a mixture; the acid liquor comprises inorganic acid and a solvent, the inorganic acid is inorganic oxyacid corresponding to oxyacid radicals of the inorganic hydrate, the solvent is water or an aqueous solution, and the aqueous solution is a solution formed by water and polyol; covering the mixture and standing to obtain a material after standing; and carrying out heat treatment on the material after standing to obtain an intermediate product which comprises a stable anhydrous substance corresponding to the inorganic hydrate and an acid solution after the reaction is finished. According to the method provided by the invention, dehydration and structural transformation of the inorganic hydrate can be realized at a relatively low temperature, so that energy can be remarkably saved, carbon emission can be reduced, conditions in the whole reaction process are milder, the method is easier to implement, equipment investment is reduced, and the method is suitable for industrial application.

The application provides a preparation method of a silver-copper ferrite-iron-based metal organic framework composite material, and comprises the following steps: step S1, a copper ferrite material is prepared by improving a pH value and a hydrothermal temperature and by adding different additives through a modified solvothermal method; step S2, an iron-based metal organic framework material is prepared by improving a pH value and stirring conditions at room temperature through a sol-gel method; step S3, a heterostructure is formed by combining the copper ferrite material and the iron-based metal organic framework material through an ultrasonic method, so that a copper ferrite-iron-based metal organic framework composite material is obtained; and step S4, a silver quantum dot is photo-deposited on the surface of the copper ferrite-iron-based metal organic framework composite material through a photo-deposition method, so that a silver-copper ferrite-iron-based metal organic framework composite material is prepared. The silver-copper ferrite-iron-based metal organic framework composite material prepared by the application can be used for removing oxygen-containing acid salt pollutants in drinking water, such as nitrate, bromate and chlorite, and has a wide application prospect.

The invention relates to a solar cell, a power generation device and a power utilization device. The solar cell comprises a hole transport layer and a light absorption layer which are stacked in sequence; one side, close to the light absorption layer, of the hole transport layer comprises a first hole transport sub-layer, the first hole transport sub-layer comprises a functionalized hole transport material, and the functionalized hole transport material comprises a polyaromatic compound with a structure as shown in a formula (1); each Ar is independently a p + 2 valent aromatic group; each p is independently 0 or a positive integer, the sum of the n p is a positive integer, and n is an integer selected from 3 to 10; each A is independently selected from an oxyacid group or an oxyacid salt; m is an integer selected from 0 to 10; each L is independently a divalent linking group, and each L independently provides a spacer atom or a spacer ring; and S01 and S02 are respectively and independently end-capping groups. The solar cell has excellent photoelectric conversion efficiency and performance stability.

The present invention relates to a method for obtaining a bath of molten chloride salts comprising at least one actinide in which the oxidation state and / or degree of oxidation of said at least one actinide are predetermined according to the intended application, comprising the following steps: (a) establishing, for said at least one actinide, its potential-oxoacidity diagram at a given temperature T in a bath of molten chloride salts, (b) from the potential-oxoacidity diagram established in step (a), defining the potential-oxoacidity domain in which said at least one actinide is in the predetermined oxidation state and / or degree of oxidation, (c) selecting at least three different compounds which are different from said at least one actinide setting, at the temperature T, the potential and oxoacidity of the bath of molten chloride salts in the domain defined in step (b), it being possible for one of said at least three compounds to be the chloride ion contained in the bath of molten chloride salts, then (d) introducing, into a bath of molten chloride salts comprising said at least one actinide at the temperature T, said at least three compounds selected in step (c). The present invention relates to the use of various mixtures or compositions in the preparation of a nuclear fuel, during its operation or else during its reprocessing.

The present invention aims to provide a microbiota improving agent for improving at least one of mucosal microbiota, skin microbiota, or nail microbiota, the microbiota improving agent exhibiting a high pathogenic bacteria inhibitory effect while maintaining resident non-pathogenic bacteria, thus persistently improving the microbiota balance. The present invention relates to a microbiota improving agent for improving at least one of mucosal microbiota, skin microbiota, or nail microbiota, the microbiota improving agent containing: a substance (X); and a base (Y) containing a non-volatile component, the substance (X) including at least one selected from the group consisting of a compound (X1) having two or more hydroxy groups contained in at least one oxoacid group and a salt of the compound (X1), a compound (X2) having one hydroxy group contained in an oxoacid group and a salt of the compound (X2), a heterocyclic compound (X3) having no oxoacid group and a salt of the compound (X3), and a ketone (X4) having no oxoacid group. In the compound (X1), a total mass percentage of the at least one oxoacid group, a hydroxy group not contained in the oxoacid group, a carbonyl group not contained in the oxoacid group, carbon atoms contained in an imidazole skeleton and a pyridine skeleton, and nitrogen atoms contained in the imidazole skeleton and the pyridine skeleton is 45% by mass or more based on a molecular weight of the compound (X1). The compound (X2) has an atom having an unshared electron pair, the atom excluding atoms contained in the oxoacid group and atoms contained in an amino group not constituting an imidazole skeleton and in an amino group not constituting a pyridine skeleton. In the compound (X2), a total mass percentage of the oxoacid group, a hydroxy group not contained in the oxoacid group, a carbonyl group not contained in the oxoacid group, carbon atoms contained in an imidazole skeleton and a pyridine skeleton, and nitrogen atoms contained in the imidazole skeleton and the pyridine skeleton is 55% by mass or more based on a molecular weight of the compound (X2). The heterocyclic compound (X3) has an imidazole skeleton or a pyridine skeleton and at least one of a hydroxy group or a carbonyl group, or has two or more skeletons selected from the group consisting of an imidazole skeleton and a pyridine skeleton. The ketone (X4) has a linear β-diketone structure. The substance (X) has a molecular weight of 550 or less. The non-volatile component has an HLB value of 7 or more. The microbiota improving agent satisfies the following conditions (i) and (ii): (i) the microbiota improving agent has a worked penetration of 100 to 400 as measured in accordance with JIS K 2220; and (ii) the microbiota improving agent has a viscosity at 37° C. of 1 to 4,000 Pa·s as measured with a cone-and-plate rheometer.

This invention relates to the field of organic synthesis and discloses a method for preparing bifenthrin. The method includes: contacting kungfu acid and 2-methyl-3-phenylbenzyl alcohol in the presence of a catalyst composition to carry out an esterification reaction; wherein the catalyst composition includes component A and component B; wherein component A is selected from oxyacid esters of group IVB elements and / or compounds formed by group IVB elements and alcohols; wherein component B is selected from at least one of inorganic salts of copper, oxides of copper, oxides of tin, and inorganic salts of tin. The bifenthrin prepared by this method has a high yield (>98%), high purity (up to 99.4%), and produces fewer bifenthrin isomers (<0.5%), meeting market requirements. The entire process is highly efficient and environmentally friendly.

This invention provides a high-temperature stabilizer for sulfonated drilling fluids, its preparation method, and its application. The stabilizer comprises low-valent sulfur oxyacid salts and hydroxyalkyl sulfonates. The high-temperature stabilizer for sulfonated drilling fluids is prepared according to the following steps: mixing low-valent sulfur oxyacid salts and carbonyl compounds in water, adding an inorganic alkali to adjust the pH to 8-10, and reacting under high-temperature sealed conditions to obtain the high-temperature stabilizer for sulfonated drilling fluids. The low-valent sulfur oxyacid salts include divalent sulfur oxyacid salts and / or tetravalent sulfur oxyacid salts; the carbonyl compounds include aldehydes and / or ketones; the molar ratio of sulfur in the low-valent sulfur oxyacid salts to the carbonyl groups in the carbonyl compounds is (1.2-2.0):1. The high-temperature stabilizer in this invention is a composition formed by low-valent sulfates and hydroxyalkyl sulfonates. This composition can simultaneously eliminate the active hydroxymethyl and hydrogen atoms on the phenolic ring structure of the sulfonated material and can also inhibit the desulfonation reaction of the treatment agent.

The invention provides a preparation method of a Cu-SSZ-13 molecular sieve with low surface hydroxyl content, which comprises the following steps: mixing the Cu-SSZ-13 molecular sieve with a precursor to be coated, filtering, drying and roasting to obtain the Cu-SSZ-13 molecular sieve, the precursor to be coated comprises a solid precursor or a liquid precursor; the solid precursor comprises oxides and hydroxides of Mo and W; the liquid precursor comprises inorganic oxysalts or complexes of Mo and W. The method belongs to post-treatment modification of the Cu-SSZ-13 molecular sieve, and Mo and W oxides coat the surface of the Cu-SSZ-13 molecular sieve through condensation of Mo and W precursors and hydroxyl groups on the surface of the Cu-SSZ-13 molecular sieve in a high-temperature roasting process, so that the content of the hydroxyl groups on the surfaces of crystal grains of the molecular sieve is reduced.

The invention discloses an isocyanate curing agent, which is prepared from the following components in parts by weight: 100 parts of isocyanate, 0.03 to 0.11 part of oxyacid polymerization inhibitor, 8 to 35 parts of ester organic compound solvent and 0.10 to 0.16 part of polyol ester modifier. According to the isocyanate curing agent disclosed by the invention, a proper amount of oxyacid is added as a polymerization inhibitor, so that the self-polymerization reaction of isocyanate can be effectively inhibited; a chemical environment for inhibiting reaction with water can be established in an isocyanate system, so that the isocyanate and the water are effectively prevented from chemical reaction, the generation of carbon dioxide gas is reduced, the defects of bubbles, bubbling and the like of a product are avoided, and the appearance quality of the product is improved. The isocyanate curing agent disclosed by the invention is applied to casting production of steel castings, and the mechanical property, the curing property and the like are obviously improved. In the actual molding process, compared with an unmodified isocyanate curing agent, the isocyanate curing agent disclosed by the invention has the advantages that the molding sand strength is improved by more than 10%, and the sand mold curing and drawing time is shortened by about 15%.

[Problem] The present invention addresses the problem of providing a papermaking additive that is capable of sufficiently exhibiting the effect required for additives for papermaking even in a deteriorated papermaking environment, and that does not cause a change in a liquid mixture such as gelation or an increase in the viscosity of the liquid mixture, or separation or deposition of components, particularly when the concentration of the liquid mixture is high. [Solution] This papermaking additive is characterized by: comprising (A) an amphoteric ion polymer having (a) a (meth)acrylamide monomer unit, (b) a cationic monomer unit, and (c) an anionic monomer unit, (B) a cationic polymer that is a hydrolysate of a polymer having a vinylformamide monomer unit, and (C) an oxoacid and / or oxoacid salt having a valence of two or more; and being an aqueous solution in which the total concentration of (A) and (B) is 10-25 mass%.