摘要:
Method for manufacturing a ceramic electronic component such as a voltage-dependent non-linear resistor element and a semiconductive ceramic capacitor is disclosed, in which a precisely uniform metal coating is formed on a surface of a ceramic and the metal coating is then heat treated to convert the metal of the metal coating to a metal compound to form a metal compound coating on the surface of the ceramic and/or diffuse a portion of or all of the metal coating into the ceramic, for attaining completely different electric properties than those of untreated ceramic. The present method is particularly useful in the application to a semiconductive ceramic capacitor.
摘要:
A method for producing a polyacrylic water-absorbent resin powder includes the steps of: producing an acrylic monomer solution in which gas is dissolved and/or dispersed; polymerizing the monomer solution in the absence of a surface active agent or in the presence of not more than 300 ppm of a surface active agent; during or after polymerizing, fragmenting the resulting hydrated gel crosslinked polymer; and drying the fragmented hydrated gel crosslinked polymer, the gas being dissolved and/or dispersed in the monomer solution by (a) applying pressure to the acrylic monomer solution and the gas; (b) creating swirling flows of the acrylic monomer solution and the gas; or (c) introducing the gas with the acrylic monomer solution via fine holes. The production method efficiently produces a water-absorbent resin having an excellent water-absorption rate without deteriorating a liquid-absorbent property of a sanitary product or the like.
摘要:
The present invention is to provide a drying method by which both cost reduction and superior physical properties can be attained in a step which comprises subjecting a water-containing gel-like crosslinked polymer obtained by polymerizing an aqueous monomer solution to fine granulation during or after the polymerization, and drying the resultant particulate water-containing gel-like crosslinked polymer with a through-circulation band dryer. The method has a feature in that the drying conditions over a period from a time of introducing the particulate water-containing gel-like crosslinked polymer into a drying zone of the through-circulation band dryer to a time of reaching a solid content concentration thereof to 80% by weight, satisfy that (1) a difference of temperature between a temperature of hot air blown to a particulate hydrogel layer and a temperature measured after the hot air passes through the particulate hydrogel layer is 20 to 70° C.
摘要:
The present invention has an object to provide a particulate water-absorbing composition, a production process therefor, and an absorbent article comprising this particulate water-absorbing composition, wherein the particulate water-absorbing composition causes little coloring of other materials and further is of high safety, and can provide excellent deodorizability and excellent absorption properties to absorbent articles such as diapers in the case where combined into the absorbent articles. As a means of achieving this object, a particulate water-absorbing composition according to the present invention is characterized by comprising a plant powder and a water-absorbent resin, wherein a surface portion and/or its vicinity of the water-absorbent resin is surface-treated with a crosslinking agent, and wherein the particulate water-absorbing composition exhibits an offensive-odor removal index of not less than 180 wherein the offensive-odor removal index is represented by the following equation: offensive-odor removal index=1.1×hydrogen sulfide removal ratio+2.0×methylmercaptan removal ratio+0.3×ammonia removal ratio.
摘要:
A method for mixing a water-absorbent resin and a surface cross-linking agent-containing solution to repress aggregates is equipped. The water-absorbent resin and the surface cross-linking agent-containing solution is mixed with a plow-shaped mixing device which is equipped with an inner wall formed of material manifesting an interfacial contact angle of not less than 60° to water and possessing a temperature of heat distortion of not lower than 70° C., a plow-shaped stirring vane and a disintegrating blade.
摘要:
An object of the present invention is to provide a water absorbent having excellent gel properties and showing excellent properties when used in a water-absorbing material of a sanitary/hygienic material such as paper diaper. Moreover, another object of the present invention is to provide a water absorbent which is safe and excellent in liquid permeability, and in which an amount of liquid permeability improver for improving the liquid permeability is reduced. The water absorbent is made from a water-absorbing resin prepared by a specific polymerization method and having a high degree of cross-linking, a high liquid holding property and a high gel strength (its swelling pressure of gel layer of is 35 kdyne/cm2 or more). This water absorbent is further processed to have a particular particle size distribution (95 wt % or more of its particles are less than 850ƒÊm but not less than 106ƒÊm, and logarithmic standard deviation (ƒĐƒÄ) is in a range of 0.25 to 0.45) and then surface cross-linked. After that, a liquid permeability improver is added therein.
摘要:
The present invention provides such a production process that a low-cost water-absorbent resin having excellent quality can be obtained by reasonable steps in aqueous solution polymerization. The production process for a water-absorbent resin comprises a polymerization setup that includes the steps of: supplying an aqueous solution of a water-soluble unsaturated monomer component including a major proportion of acrylic acid and/or its salt into a polymerization vessel causing shearing action; and then carrying out polymerization, involving crosslinking, of the water-soluble unsaturated monomer and at the same time carrying out fine division of the resultant hydrogel; with the production process being characterized in that the aqueous solution of the water-soluble unsaturated monomer component as supplied into the polymerization vessel has a temperature of not lower than 40° C.
摘要:
The present invention provides: a process for treating a particulate water-absorbent resin, which enables to carry out pulverization stably in a process for producing a particulate water-absorbent resin, and transportation or storage of the particulate water-absorbent resin stably during or after producing the particulate water-absorbent resin, and to prevent contamination of cohered matters of the particulate water-absorbent resin; and involves no or little deterioration of properties. The process for treating a particulate water-absorbent resin is characterized by carrying out at least one selected from the group consisting of: (1) heating at least one portion of a surface getting contact with the particulate water-absorbent resin from the outside, (2) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin at 30 to 150° C., and (3) maintaining the temperature of at least one portion of a surface getting contact with the particulate water-absorbent resin above a temperature that is lower than a temperature of the particulate water-absorbent resin by 20° C.
摘要:
A maleic acid-based copolymer is provided which has a weight-average molecular weight of 1,000 to 100,000, a calcium ion-capturability of 300 mgCaCO.sub.3 /g or higher calculated as calcium carbonate, and a clay-dispersibility of 1.2 or higher. Another maleic acid-based copolymer is also provided which has a level of adsorption to clay within the range of 20 to 90% and a calcium ion-stabilization degree constant of 4.0 or larger. These copolymers are obtainable by a process including the steps of: charging maleic acid and/or its salt (A) into a reaction vessel, in such a manner that the concentration of the (A) will be 35% by weight or higher; adding hydrogen peroxide into the vessel after the charging step, in such a manner that the amount of hydrogen peroxide is within the range of 3 to 20% by weight of the (A); and adding a water-soluble ethylenically unsaturated monomer (B) into the vessel after the charging step and within 30 to 500 minutes after initiation of a reaction, in such a manner that the ratio (A)/(B) is within the range of 95/5 to 5/95 in mol ratio, wherein the adding of the monomer (B) is completed 10 to 300 minutes later than completion of the step of adding hydrogen peroxide. The copolymers are used for detergent compositions, inorganic pigment-dispersing agents, water-treating agents and fiber-treating agents.
摘要:
A maleic acid-based copolymer is provided which has a weight-average molecular weight of 1,000 to 100,000, a calcium ion-capturability of 300 mgCaCO.sub.3 /g or higher calculated as calcium carbonate, and a clay-dispersibility of 1.2 or higher. Another maleic acid-based copolymer is also provided which has a level of adsorption to clay within the range of 20 to 90% and a calcium ion-stabilization degree constant of 4.0 or larger. These copolymers are obtainable by a process including the steps of: charging maleic acid and/or its salt (A) into a reaction vessel, in such a manner that the concentration of the (A) will be 35% by weight or higher; adding hydrogen peroxide into the vessel after the charging step, in such a manner that the amount of hydrogen peroxide is within the range of 3 to 20% by weight of the (A); and adding a water-soluble ethylenically unsaturated monomer (B) into the vessel after the charging step and within 30 to 500 minutes after initiation of a reaction, in such a manner that the ratio (A)/(B) is within the range of 95/5 to 5/95 in mol ratio, wherein the adding of the monomer (B) is completed 10 to 300 minutes later than completion of the step of adding hydrogen peroxide. The copolymers are used for detergent compositions, inorganic pigment-dispersing agents, water-treating agents and fiber-treating agents.