PURPOSE:To provide a highly water-absorptive water-retentive material superior in water absorption properties, water retention properties, shape retention properties, etc. and useful for agriculture, horticulture, etc., by mixing a monomer having an alpha,beta-unsaturated bond with an inorganic and/or organic powder, granulating and shaping followed by polymerizing. CONSTITUTION:A monomer (e.g., acrylic acid or acrylamide) having an alpha,beta-unsaturated bond, and an inorganic and/or organic powder are mixed. As preferred examples of the inorganic powder, bentonite, zeolite, alumina, silica, barite, kaoline, etc. can be mentioned. As preferred examples of the organic powder, wood powder, pulp powder, etc. can be mentioned. Then, the mixture is granulated or shaped followed by polymerization of the monomer to provide the aimed highly water-absorptive water-retentive material. When this material is used as an agricultural or horticultural water retentive material, the air flows smoothly through it since the material maintains its shape so that root rot or the like would not occur.

Highly water absorptive water retentive material

PURPOSE:The titled inexpensive dispersant having viscosity-lowering ability, causing no caking phenomena even by allowing slurry to stand for a long period, comprising a water-soluble copolymer having two specific constituent units as a main component, having a fixed molecular weight. CONSTITUTION:(A) An alkylolamide compound such as N-methylolacrylamide, N-ethylolacrylamide, etc. shown by the formula I (R is H, or 1-3C alkyl; X is one bond, methylene, or ethylene) is copolymerized with (B) a compound shown by the formula II (R2 is H, or methyl; R3 is OH, or aimno) in water, a hydrous solvent, or an organic solvent with a polymerization initiator under heating, to give a water-soluble copolymer having constituent units shown by the formula IIIand formula IV, having 1,000-500,000, preferably 1,000-30,000mol.wt., which is used as a main component of a dispersant. The composition of the polymer has 5-80mol% component A and 95-20mol% component B. Presence of 80mol% of both components in the polymer is essential to the dispersant.

Dispersant for slurry

Water absorbable fiber composite

Production of disc blade for cutting straw

PURPOSE:To obtain a water-insoluble and highly water-absorbing sheet like article easily in a short process, by a method wherein a short fiber is uniformly dispersed in an aqueous solution of a (salt)crosslinkable hydrophilic polymer and the resulting fiber containing dispersion is heated and dried to crosslink the aforementioned polymer. CONSTITUTION:In an aqueous solution or an aqueous dispersion (A) of a self- crosslinkable hydrophilic polymer or a hydrophilic polymer crosslinkable by a crosslinking agent, for example, a copolymer of N-methylol acrylamide and acrylic acid, a short fiber (B) comprising a (semi)synthetic or a natural fiber with a length of 0.1-20mm. is uniformly dispersed in an amount of 50-200pts.wt. per 100pts.wt. component A and, after the aforementioned short fiber containing hydrophilic aqueous solution is cast to a thin film like form generally and, according to necessity, the formed thin film is foamed, the resulting thin film is heated and dried at 30 deg.C or more to form a crosslinked structure in the component A to obtain an objective sheet. USE:This sheet is used as a sanitary material or a dehydrating material.

Tamaki Yoshifumi

Papers

Preparation of highly water absorbable sheet like article