Daiso Co., Ltd.

Tohru Matsutomi

Yasumi Shimizu

Shin-ichiro Nakamura

Thomas Daniel

Kaoru Nakao

An allyl type crosslinking agent for use in production of a super water-absorbent polymer comprising a polymerizable compound having a carbon-carbon double bond or a salt thereof. The crosslinking agent comprises a linear hydroxypolyallyl ether having at least one hydroxyl group and at least two allyl groups obtained by allyletherification of hydroxyl groups in a linear polyol compound selected from the group consisting of erythritol, xylitol and sorbitol. This allyl type crosslinking agent is highly soluble in an aqueous solvent, and can give an excellent super water-absorbent polymer, which cannot be obtained in the prior arts, having high levels of both of water absorptivity under atmospheric pressure and water absorptivity under pressurized conditions.

Crosslinking agent based on linear hydroxypolyallyl ether

In the production of allyl ethers of polyol by reacting a straight-chain polyol compound with an allyl halide in the presence of an alkali metal hydroxide, wherein the straight-chain polyol compound has carbon atoms each having one hydroxyl group, the reaction between the straight-chain polyol compound and the allyl halide is proceeded in the presence of water having the amount dissolving the straight-chain polyol compound at a reaction temperature, then 14% by mol, based on total molar amount of a hydroxyl group contained in the straight-chain polyol compound, of the allyl halide is added to a reaction system before at least part of water is released out of the reaction system.

Process for producing allyl ether

A crosslinking agent containing a polyallyl ether compound having at least one hydroxyl group derived from a glycidyl group and at least two allyl groups can be used for the production of a highly water-absorbing polymer comprising a polymerizable compound having a carbon-carbon double bond or a salt thereof, has a high solubility in aqueous solution of the monomer and gives a highly water-absorbing polymer having water absorptivity required at practical levels.

Growing community of inventors

Osaka, Japan

Tohru Matsutomi