Abstract: Provided are a method for producing a graphite oxide derivative capable of simply producing a high-quality graphite oxide derivative, and a high-quality graphite oxide derivative. The present invention relates to a method for producing a graphite oxide derivative, the method including the steps of oxidizing graphite; and preparing a graphite oxide derivative by reacting graphite oxide in a reaction liquid containing graphite oxide obtained in the oxidation step or graphite oxide in a graphite oxide-containing composition that is separated from the reaction liquid with a compound reactive with an oxygen-containing functional group of the graphite oxide, the method not including the step of purifying and drying the graphite oxide-containing reaction liquid between the oxidation step and the graphite oxide derivative preparation step.

Abstract: The present invention aims to provide a polymer capable of well dispersing hydrophobic particles. The present invention relates to a hydrophobic group-containing copolymer including a structural unit (A) derived from a hydrophobic group-containing monomer that is represented by the formula (1) and a structural unit (B) derived from a carboxylic acid-based monomer. The proportion of the structural unit (A) is from 16% by mass or more to 50% by mass or less based on 100% by mass of the structural units derived from all monomers constituting the copolymer, and the copolymer has a weight average molecular weight of 10,000 to 1,000,000.

Abstract: The present invention provides a water-soluble film having excellent solubility in cold water, high strength, and excellent hard-water resistance. The present invention also provides a method for simply producing such a water-soluble film. One aspect of the present invention relates to a water-soluble film including a polymer containing an anionic group other than a sulfonic acid (salt) group, and a water-soluble resin. The anionic group-containing polymer excludes an acrylic acid homopolymer. Another aspect of the present invention relates to a method for producing a water-soluble film that includes a polymer containing an anionic group other than a sulfonic acid (salt) group, and a water-soluble resin. The method includes mixing a polymer containing an anionic group other than a sulfonic acid (salt) group and a water-soluble resin.

Abstract: Provided is a water-absorbing agent which maintains a certain degree of liquid permeability and water absorption speed while also reducing re-wet in a disposable diaper, without the use of costly raw materials or costly apparatuses. The water-absorbing agent of the present invention contains a polyacrylic acid salt-based water-absorbing resin as a main component and has physical properties falling within a specific range, the physical properties being saline flow conductivity (SFC), gap fluid retention property under pressure, and a proportion of particles having a particle diameter of not less than 150 ?m and less than 710 ?m.

Abstract: The present invention provides a contraction agent for a water-absorbing resin that is used as a proppant in stratum hydraulic fracturing, the contraction agent containing: a metal ion-containing substance and a breaking agent for water-absorbing resins used in stratum hydraulic fracturing; and an iron ion-containing substance and/or ascorbic acid, and/or a persulfate. Also provided is a kit for use in stratum hydraulic fracturing, the kit provided with a swelling agent containing a water-absorbing resin, an iron ion-containing substance, and ascorbic acid, the kit being for stratum hydraulic fracturing, wherein the kit consists of A) a proppant containing a water-absorbing resin, and B) a contraction agent for the water-absorbing resin containing a metal ion-containing substance.

Abstract: The present invention provides a novel acrylic acid crosslinked polymer and the use thereof. The present invention provides the acrylic acid crosslinked polymer in which the content of soluble components is 40 wt. % or higher. The present invention also provides a method for adjusting the viscosity of a fracturing fluid in a hydraulic fracturing method, the viscosity adjustment method including: A) a step of measuring the types and quantities of metal cations which are in water and which are the object of viscosity adjustment; B) a step of selecting the type and quantity of an acrylic acid crosslinked polymer on the basis of the types and quantities of metal cations and the pH so as to achieve a viscosity that is required for fracturing in a hydraulic fracturing method; and C) a step of adjusting the viscosity of the fracturing fluid using the acrylic acid crosslinked polymer of the selected type and quantity.

Abstract: A ceramic sheet including a principal surface having particle marks is disclosed. The average width of the particle marks is 0.2 to 50 ?m, the average depth of the particle marks along the sheet thickness direction is 0.1 to 25 ?m, and the coefficient of variation of the widths of the particle marks is 0.23 or more.

Abstract: A binder composition comprising a rust inhibitor having a sulfur atom in the molecule, and a carboxyl group-containing polymer.

Abstract: A method for producing (meth)acrylic acid comprising: a step of obtaining a (meth)acrylic acid-containing gas by subjecting a (meth)acrylic acid production raw material to a catalytic gas phase oxidation reaction; a step of obtaining a (meth)acrylic acid-containing liquid by bringing the (meth)acrylic acid-containing gas into contact with a collection solvent and/or condensing the (meth)acrylic acid-containing gas by cooling; a step of obtaining crude (meth)acrylic acid by introducing the (meth)acrylic acid-containing liquid into a low-boiling separation column; a step of obtaining purified (meth)acrylic acid and a refining residue containing a glyoxal compound by purifying the crude (meth)acrylic acid; and a step of returning at least a part of the refining residue to the low-boiling separation column; wherein a returning position of the refining residue to the low-boiling separation column is located closer to a bottom side of the low-boiling separation column than a supply port of the (meth)acrylic acid-co

Abstract: At least one embodiment of the present disclosure provides a hydrogenated silane composition containing a cyclic hydrogenated silane having high storage stability. The at least one embodiment of the present disclosure relates to a hydrogenated silane composition, wherein a content ratio of a linear hydrogenated silane having Si atoms of 5 or less to a cyclic hydrogenated silane having Si atoms of 5 to 7 is 0.009 or less, wherein the cyclic hydrogenated silane comprises at least cyclohexasilane, and further comprises at least one cyclic hydrogenated silane having a branched silyl group selected from silylcyclopentasilane and silylcyclohexasilane, and wherein a content ratio of a total of the silylcyclopentasilane and the silylcyclohexasilane to the cyclic hydrogenated silane having Si atoms of 5 to 7 is 10 ppb or more on a mass basis.

Abstract: At least one embodiment of the present disclosure provides a hydrogenated silane composition containing cyclohexasilane of a cyclic hydrogenated silane having high storage stability. The at least one embodiment of the present disclosure relates to a hydrogenated silane composition, wherein a content ratio of normal hexasilane and silylcyclopentasilane to cyclohexasilane is 0.0020 or less on a mass basis.

Abstract: A method is disclosed for inexpensively and stably producing, with high productivity, water absorbent resin having excellent damage resistance. A method for producing a polyacrylic acid (salt)-based water absorbent resin, the method comprising a surface-crosslinking step, the surface-crosslinking step including a reaction step, the reaction step involving using a reactor having (i) an inner wall surface having a temperature within a range of 100° C. to 250° C. and (ii) an inside atmosphere having a dew point within a range of 60° C. to 100° C., the reaction step including heat-treating a water absorbent resin mixture so as to produce water absorbent resin powder having a temperature within a range of 90° C. to 130° C.

Abstract: Provided is a water-absorbing agent which is less likely to cause gel blocking and is suitable for a sanitary product and an absorbent article each being thin and containing a large amount of a water-absorbing agent, and which, while maintaining or hardly losing the other physical properties (a fluid retention capacity and a bulk specific gravity) of the water-absorbing agent, simultaneously achieves a high water absorbing speed (e.g., FSR), a high fluid retention capacity under load, high liquid permeability, and salt tolerance. The water-absorbing agent is a polyacrylic acid (salt)-based water-absorbing agent whose surface and its vicinity are crosslinked by an organic surface crosslinking agent, characterized by satisfying the following (A)-(D): (A) Free Swell Rate (FSR) of at least 0.

Abstract: A polyacrylic acid (salt), or a polyacrylic acid (salt)-based water-absorbing resin, contains a tracer for detecting various troubles in the water-absorbing resin during the period from the production of the water-absorbing resin to the use and discard thereof by a consumer. The polyacrylic acid (salt)-based water-absorbing resin has a stable carbon isotope ratio, as determined by accelerator mass spectrometry, of less than ?20‰ and a radioactive carbon content of 1.0×10?14 or more. The polyacrylic acid (salt)-based water-absorbing resin has: a CRC of 10 [g/g] or more; an AAP of 20 [g/g] or more; an Ext of 35 wt. % or less; a content of residual monomers of 1,000 ppm or less; a PSD in which the proportion of particles having a particle diameter of 150 ?m or larger but less than 850 ?m is 90 wt. % or more; and an FSR of 0.15 [g/g/s] or more.

Abstract: Disclosed are a polyacrylate (salt) and a polyacrylate (salt) water-absorbent resin containing a tracer which can be verified back to the manufacturing process of the water-absorbent resin when dealing with various problems with the water-absorbent resin which can occur from the manufacturing process of the water-resistant resin, during the use thereof by a consumer, up until the disposal thereof. The disclosed polyacrylate (salt) and the polyacrylate (salt) water-absorbent resin have a carbon stable isotope ratio (?13C) of at least ?20‰ when measured by accelerator mass spectrometry.

Abstract: [Object] To provide a method for stably producing a water-absorbent resin in powder form or particle form, which has excellent physical properties such as water absorption performance and the like, without any production trouble. [Solution] A method for producing a water-absorbent resin includes mixing a monomer composition, which contains at least a monomer and a pyrolytic polymerization initiator, with an organic solvent, a temperature of the organic solvent is not lower than 70° C. at time of mixing, and when a mass per unit time of the monomer in the monomer composition to be mixed with the organic solvent is expressed as an amount per unit volume of the organic solvent, a lower limit is 0.01 g/ml/min, and an upper limit is 0.2 g/ml/min.

Abstract: The object of the present invention is to provide silica particles which can provide a silica particle dispersion exhibiting excellent uniformity. The present invention is silica particles having an average primary particle diameter dBET calculated from a specific surface area by a BET method of 1 nm or more and 100 nm or less and a ratio (dDLS/dBET) of an average secondary particle diameter dDLS measured by a dynamic light scattering method to the dBET of 1.2 or less. The silica particles of the present invention preferably have a coefficient of variation in a particle diameter measured using a transmission electron microscope at a magnification of 200,000 of 20% or less.

Abstract: The present invention provides polyacrylic acid (salt)-based water-absorbing resin powder having an excellent fluid retention capacity under pressure, an excellent water absorption speed, and an excellent liquid permeability and a method for producing the polyacrylic acid (salt)-based water-absorbing resin powder. The earlier-described objects are attained by: a method for producing water-absorbing resin powder which includes adding an inorganic compound to a crosslinked hydrogel polymer obtained in a polymerization step of polymerizing a polyacrylic acid (salt) and performing crushing in specific gel-crushing conditions; and the resultant water-absorbing resin powder.

Abstract: Provided is a water absorbent resin that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having a higher liquid permeability and a higher water absorbing speed. Further provided is a water absorbent resin powder that is useful to sanitary materials such as a disposable diaper, a sanitary napkin, and a blood absorbent for medical use each having increased in absorbency of a liquid and in heat retaining property. A gel grinding device to be used to produce a water absorbent resin, includes: a screw; a feed opening; an extrusion opening; a porous plate; and a barrel, the barrel including a return preventing member provided on an inner surface thereof, and the return preventing member satisfying at least one of specific parameters.

Abstract: A water-absorbing resin having a high swollen gel elastic modulus, a high swelling capacity and a method for producing the same are provided where the water-absorbing resin includes a water soluble unsaturated monomer having a dissociable group, an internal crosslinked structure index expressed by the following numerical formula of 14 or more, a weight average molecular weight (Mw) after a hydrolysis treatment of 220,000 or less, and a molecular weight distribution (Mw/Mn) after a hydrolysis treatment of 3.40 or less: Crosslinked structure index=(Equilibrium swelling capacity with respect to 0.9 wt % physiological saline solution1/3/(Weight average molecular weight (Mw) after hydrolysis treatment)×1000000; where the hydrolysis treatment leaves 50 mg of the water-absorbing resin as a solids content to stand still in 10 g of a 0.1 mol/l aqueous sodium hydroxide solution for 3 weeks at 80° C., and the weight average molecular weight (Mw) is measured after the treatment.