摘要:
A particulate water absorbing agent of the present invention is a water absorbing agent containing a water absorbing resin as a main component, the particulate water absorbing agent containing a polyvalent metal cation and satisfying: (1) the polyvalent metal cation is contained in an amount between 0.001 wt % and 5 wt % relative to the amount of the water absorbing agent; (2) an absorbency without pressure (CRC) is not less than 28 (g/g) and an absorbency against pressure (AAP 4.83 kPa) is not less than 10 (g/g); (3) the absorbency against pressure and the absorbency without pressure satisfy 77≦AAP (4.83 kPa)+1.8×CRC≦100; and (4) a moisture content of the water absorbing agent is between 5 wt % and 20 wt %. This provides a water absorbing agent which has blocking resistance after moisture absorption, is excellent in stability to shock and suppresses Re-Wet when used in a diaper.
摘要:
A particulate water absorbing agent of the present invention is a water absorbing agent containing a water absorbing resin as a main component, the particulate water absorbing agent containing a polyvalent metal cation and satisfying: (1) the polyvalent metal cation is contained in an amount between 0.001 wt % and 5 wt % relative to the amount of the water absorbing agent; (2) an absorbency without pressure (CRC) is not less than 28 (g/g) and an absorbency against pressure (AAP 4.83 kPa) is not less than 10 (g/g); (3) the absorbency against pressure and the absorbency without pressure satisfy 77≦AAP (4.83 kPa)+1.8×CRC≦100; and (4) a moisture content of the water absorbing agent is between 5 wt % and 20 wt %. This provides a water absorbing agent which has blocking resistance after moisture absorption, is excellent in stability to shock and suppresses Re-Wet when used in a diaper.
摘要:
A method for producing a water absorbent resin comprises the steps of: (i) polymerizing a monomer including an unsaturated monomer containing a carboxyl group, in the presence of an internal cross-linking agent (A) having two or more radical polymerizable unsaturated groups in its single molecule and in the presence of a non-polymeric internal cross-linking agent (B) having in its single molecule two or more functional groups each of which allows formation of an ester bond or an amide bond by reacting with a carboxyl group so as to obtain a cross-linked polymer hydrogel; (ii) crushing the cross-linked polymer hydrogel obtained in the step (i); and (iii) drying crushed cross-linked polymer hydrogel products obtained in the step (ii), wherein: an amount of the internal cross-linking agent (A) is 0.01 mol % or more and 0.2 mol % or less relative to an amount of the unsaturated monomer containing a carboxyl group, and a molar ratio (B)/(A) of the internal cross-linking agent (A) and the non-polymeric internal cross-linking agent (B) is 0.01 or more and 1.8 or less.
摘要:
The invention provides a novel inorganic fiber composed of the elements of silicon, carbon, boron and nitrogen of which the Si/B molar ratio is 2:1 to 200:1. The inorganic fiber is obtained by a method comprising the steps of: (a) preparing an organoborosilicon polymer by heating a mixture of an organopolysilane and an organoborazine compound, e.g. B-trimethyl-N-triphenyl borazine, to effect thermal decomposition and polycondensation reaction; (b) spinning the polymer into a fibrous form; (c) infusibilizing the fiber of the polymer by thermally oxidizing in an oxidizing atmosphere or by irradiating with ionizing radiations; and (d) calcining the infusibilized fiber at 900.degree. to 1800.degree. C. The inventive inorganic fiber is more stable at high temperatures than conventional silicon carbide fibers.
摘要:
The liquid detergent composition of the invention comprises a halogenated hydrocarbon solvent, e.g. methylene chloride, an anionic and/or non-ionic surface active agents, a quaternary ammonium hydroxide, e.g. tetramethyl ammonium hydroxide and choline, and, optionally, a lower aliphatic alcohol, e.g. methyl alcohol, each in a limited proportion. The detergent composition is very effective in the cleaning works of articles of a transparent plastic resin, e.g. polycarbonate resin, and metal or glass molds for the preparation of such resin articles by casting polymerization, of which uppermost cleanness on the surface is very essential in respect of oily, greasy and resinous contaminants.
摘要:
To provide a water absorbing agent which is excellent in balance between absorbency and liquid permeability against pressure and is excellent in flowability at the time of moisture absorption. The water absorbing agent comprises water absorbent resin particles and an organic surface additive, wherein: the organic surface additive having (i) a reactive group for a functional group of a surface of each water absorbent resin particle and (ii) a hydrophobic group exists on the surface of the water absorbent resin particle, and the hydrophobic group has a hydrocarbon group whose carbon number is 8 or more, and a ratio of an oxyalkylene group in a molecular mass of the organic surface additive is 0 or more and 25 mass % or less.
摘要:
The invention provides a method for the preparation of an ultrafine powder of silicon carbide having an extremely fine and uniform particle size distribution of spherical agglomerate particles each formed of crystallites of 5 nm or smaller in size. The silicon carbide powder is prepared by the vapor phase pyrolysis of a specified methyl hydrogen(poly)silane as diluted with a carrier gas, e.g. hydrogen, to give a concentration of 40% by volume or lower at a temperature of 750.degree. to 1600.degree. C. The silicon carbide powder can readily be sintered at a temperature of 1750.degree. to 2500.degree. C. even without addition of a sintering aid to give a sintered body of extremely high density reaching 80% or larger of the theoretical value which can never be obtained of the conventional silicon carbide powders.
摘要:
The invention provides a novel and efficient method for the preparation of methyl hydrogensilanes, e.g. dimethyl silane, 1,1,2,2-tetramethyl disilane and 1,1,2,2,3,3-hexamethyl trisilane, with large demand in the industry of silicones as an intermediate for the synthesis of other valuable organosilicon compounds such as methyl hydrogenchlorosilanes. The inventive method comprises pyrolysis of a methyl polysilane composed of at least 60% by moles of dimethylsilicon units, the balance being monomethyl- and trimethylsilicon units, at a temperature in the range from 350.degree. to 800.degree. C.
摘要:
The present invention provides a water absorbing agent, and a method for producing the water absorbing agent. The water absorbing agent includes water absorbent resin particles, an organic acid and/or salt thereof having carbon number of 10 or more and not more than 30 in its molecule, and a water-soluble polyvalent cation. The method includes the step (i) of mixing the water absorbent resin particles, the organic acid and/or salt thereof having carbon number of 10 or more and not more than 30 in its molecule, and the water-soluble polyvalent cation with one another.
摘要:
A method for producing a water absorbent resin comprises the steps of: (i) polymerizing a monomer including an unsaturated monomer containing a carboxyl group, in the presence of an internal cross-linking agent (A) having two or more radical polymerizable unsaturated groups in its single molecule and in the presence of a non-polymeric internal cross-linking agent (B) having in its single molecule two or more functional groups each of which allows formation of an ester bond or an amide bond by reacting with a carboxyl group, while crushing a cross-linked polymer hydrogel; and (ii) drying the cross-linked polymer hydrogel obtained in the step (i), wherein: an amount of the internal cross-linking agent (A) is 0.01 mol % or more and 0.2 mol % or less relative to an amount of the unsaturated monomer containing a carboxyl group, and a molar ratio (B)/(A) of the internal cross-linking agent (A) and the non-polymeric internal cross-linking agent (B) is 0.01 or more and 1.8 or less.