摘要:
The invention provides [I] a water-absorbing agent composed of a water-absorbing resin powder having the molecular chains near its surface being crosslinked, said powder being obtained by mixing 100 parts by weight of a powder of a carboxyl-containing water-absorbing resin selected from the group consisting of a hydrolyzate of a starch-acrylonitrile graft polymer, a partially neutralized product of a starch-acrylic acid graft polymer, a saponification product of a vinyl acetate-acrylic ester copolymer, a hydrolyzate of an acrylonitrile copolymer, a crosslinked product of a hydrolyzate of an acrylonitrile copolymer, a hydrolyzate of an acrylamide copolymer, a crosslinked product of a hydrolyzate of an acrylamide copolymer, a partially neutralized product of polyacrylic acid, and a crosslinked product of partially neutralized polyacrylic acid with 0.001 to 10 parts by weight of a polyhydric alcohol, 0.01 to 8 parts by weight of a hydrophilic organic solvent and 0 to 8 parts by weight of water, and heating the mixture at a temperature of at least 90.degree. C. to react the water-absorbing resin powder with the polyhydric alcohol; [II] a water-absorbing agent composed of a mixture of the water-absorbing agent [I] with finely divided silica; [III] a water-absorbing agent obtained by pulverizing and granulating a mixture of the water-absorbing agent [I] with an aqueous liquid; and [IV] a water-absorbing agent composed of a mixture of the water-absorbing agent [III] with finely divided silica.
摘要:
An absorbent resin composition obtained by copolymerizing in an aqueous solution a mixture of 100 parts by weight of an acrylate salt monomer (B) composed of 0 to 50 mol % of acrylic acid and 50 to 100 mol % of an alkali metal acrylate and 0.001 to 5 part by weight of a crosslinkable monomer (C) having 2 to 4 groups selected from the group consisting of CH.sub.2 .dbd.CHCO--, CH.sub.2 .dbd.C(CH.sub.3)C0-- and CH.sub.2 .dbd.CH-CH.sub.2 -- in the molecule in the presence of at least one surface-active agent (A) selected from the group consisting of water-soluble surface-active agents and water-dispersible surface-active agents in the presence of a water-soluble radical polymerization initiator while maintaining the initial concentration of said mixture in the range of from 25% by weight to saturation, and then drying the resulting gel-like hydrous polymer under heat; and an absorbent resin composition obtained by pulverizing said absorbent resin composition to form a resin powder, and blending said resin powder with 0.01 to 10 parts by weight, per 100 parts by weight of said resin powder, of ultra-microscopic silica having a specific surface area, measured by the Brunauer-Emmett-Teller method, of at least 50 m.sup.2 /g and a particle diameter of not more than about 0.05 micron: and a process for producing the same.
摘要:
A method for the production of an absorbent resin, which method comprises mixing 100 parts by weight of (A) a hydrated gel of absorbent resin which is resulted from aqueous solution polymerization having a polymerization ratio in the range of from 60 to 99%, an average particle diameter in the range of from 0.1 to 200 mm, a water content in the range of from 30 to 90% by weight, and a temperature in the range of from 40.degree. to 110.degree. C., with from 1 to 50 parts by weight of (B) a substantially dry fine absorbent resin powder having an average particle diameter smaller than the average particle diameter assumed by said hydrated gel of absorbent resin (A) while in a dried state, then raising the polymerization ratio of said hydrated gel of absorbent resin (A) to a level higher than the polymerization ratio of said hydrated gel when being mixed.
摘要:
A process for preparing an absorbent resin includes the steps of: preparing a first crosslinking agent (A) including at least two polymerizable unsaturated bonds; preparing a second crosslinking agent (B) including at least two polymerizable unsaturated bonds and hydroxyl groups; preparing a crosslinking agent including (A) and (B) with a ratio of (A) to (B) ranging from 95/5 to 50/50; and polymerizing a hydrophilic unsaturated monomer having at least one carboxyl group using the crosslinking agent. The crosslinking agent includes a crosslinking agent which includes a main component at least 90 percent by weight, the main component being an ester having at least two polymerizable unsaturated bonds, wherein the ester is composed of a polyhydroxy alcohol (C) having not more than six carbon atoms and at least three hydroxy groups, and an unsaturated carboxylic acid (D); and a molecular weight ratio of the main component to a standard compound (E) is in the range of from 0.7/1 to less than 1.3/1, (E) being an ester composed of (C) that composes the main component, and (D) that composes the main component, in which all the hydroxy groups in (C) are ester-linked with (D).
摘要:
A cylinder head gasket 1 is sandwiched between a cylinder head 2 and a cylinder block 3 with a cylinder bore 4 and includes a substrate 10 with a combustion chamber hole 14 drilled at a position of the cylinder bore 4, and seal plates 11 to 13, the substrate 10 and the seal plates are stacked on one another. Fixation members 21 and 22 are secured to the substrate around a periphery of the combustion chamber hole. The seal plates include an engagement hole 23 formed therein and with which the fixation members are engaged. The engagement hole is engaged with the fixation members. The fixation members are sandwiched between the cylinder head and the cylinder block. The cylinder head and the cylinder block can be firmly coupled together via the fixation members.
摘要:
A piston, which reciprocates in a cylinder bore of an engine, is supplied with lubricating oil. The piston includes pin bosses provided under a piston head, a symmetrical pair of skirts, and side walls connecting the pin bosses and the skirts. The side walls have openings, which communicate the outer side of the walls with the inner side of the walls under the middle section of the head. A recess is defined in the lower surface of the head to receive a spray of lubricating oil. The width of the recess is wider than the width of each skirt at its basal portion. This causes the oil supplied to the lower surface of the head during movement of the piston to be injected against the recess and thus be diffused. As a result, oil passes by the basal section of the skirts and permeates into the space defined by the cylinder bore and the skirts.
摘要:
A method for the production of a water-absorbent agent comprises mixing an absorbent resin containing a carboxyl group with an additive soluble in the aqueous solution of at least one member selected from the group consisting of inorganic acids, organic acids, and polyamino acids and a cross-linking agent capable of reacting with the carboxyl group. A water-absorbent agent obtained by adding from 0.005 to 8 parts by weight of an epoxy compound to 100 parts by weight of a water-absorbent resin, exhibiting an absorption capacity without load of at least 45 (g/g), an absorption capacity under load of 20 g/cm.sup.2 of not less than 30 (ml/g) and having a residue amount of an epoxy compound of not more than 2 ppm. A water-absorbent composition comprises a polyamino acid (salt) and a water-absorbent resin containing a carboxyl group.
摘要:
A cylinder head gasket 1 is sandwiched between a cylinder head 2 and a cylinder block 3 with a cylinder bore 4 and includes a substrate 10 with a combustion chamber hole 14 drilled at a position of the cylinder bore 4, and seal plates 11 to 13, the substrate 10 and the seal plates are stacked on one another. Fixation members 21 and 22 are secured to the substrate around a periphery of the combustion chamber hole. The seal plate includes an engagement hole 23 formed therein and with which the fixation members are engaged. The engagement hole is engaged with the fixation members. The fixation members are sandwiched between the cylinder head and the cylinder block. The cylinder head and the cylinder block can be firmly coupled together via the fixation members. This allows deformation of the cylinder block caused by explosion pressure in an engine to be suppressed. As a result, possible degradation of sealability can be prevented.
摘要:
A method for the production of a water-absorbent agent comprises mixing an absorbent resin containing a carboxyl group with an additive soluble in the aqueous solution of at least one member selected from the group consisting of inorganic acids, organic acids, and polyamino acids and a cross-linking agent capable of reacting with the carboxyl group. A water-absorbent agent obtained by adding from 0.005 to 8 parts by weight of an epoxy compound to 100 parts by weight of a water-absorbent resin, exhibiting an absorption capacity without load of at least 45 (g/g), an absorption capacity under load of 20 g/cm2 of not less than 30 (ml/g) and having a residue amount of an epoxy compound of not more than 2 ppm. A water-absorbent composition comprises a polyamino acid (salt) and a water-absorbent resin containing a carboxyl group.
摘要:
A method of adjusting the hardness of a metallic material includes the steps of induction-tempering both of tough and hard portions which have been given a hardness required for the hard portion to a hardness required for the tough portion, induction-hardening the hard portion alone to a hardness higher than that required for the hard portion, and induction-tempering the hard portion alone to a hardness required for the hard portion.