Daicel Chemical Industries, Ltd.

Daicel Huels Ltd.

Daicel Corporation

Yoshiyuki Ikemoto

Shoji Watanabe

Takuya Miho

Naoki Nakashima

Tomohisa Isobe

Takaaki Murai

Toru Ikuta

Kimio Inoue

Hideo Yabune

Manabu Uchida

Younosuke Kato

A saturated polyester obtained by a reaction of a polycarboxylic acid component comprising a polycarboxylic acid having 2 to 6 carbon atoms in the main chain (e.g. maleic anhydride), and a polyol component comprising a polyhydric alcohol having 2 to 4 carbon atoms or its condensate is used as a cement retarder. A retardative sheet can be formed by applying or impregnating a composition comprising the retarder and a tacky adhesive to a base sheet. By forming a predetermined pattern with the use of the retarder or sheet in a form, depositing a mortar composition, washing a surface of the hardened concrete, and washing out uncured mortar, a figure or a washing finished surface is formed on a surface of a concrete product.

Cement retarder and cement retardative sheet

A process for producing a lactone polymer which comprises reacting an ester compound synthesized from an alcohol and an acid or acid anhydride thereof with a lactone and a ring-opening polymerization initiator without being accompanied by condensation. The thus produced lactone polymer is effective for preventing shrinkage of thermosetting resins, particularly unsaturated polyester resins.

Process for producing lactone polymer and an anti-shrinking

A polyurethane having excellent elastic recovery is obtained by reacting an organic diisocyanate with a polycaprolactone polyester-diol prepared from a dihydric alcohol, a dibasic acid, an ester thereof or an anhydride thereof and .epsilon.-caprolactone or/and hydroxycaproic acid and having a hydroxyl value of 35 to 150 KOH mg/g and a content of .epsilon.-caprolactone and hydroxycaproic acid of 69 to 95% by weight.

Polyurethane having excellent elastic recovery and elastic filament of

A process for producing cellulose diacetate is disclosed which comprises the steps of:

Process for producing cellulose acetate

Cellulose acetate is prepared acetylating cellulose at a high temperature of 50.degree.-85.degree. C. and then ripening the acetylated cellulose at a high temperature of 110.degree.-120.degree. C.

Process for preparation of cellulose acetate

Cellulose diacetate having improved resistance to delustering in hot water is produced by acetylation cellulose in the presence of a catalyst and then hydrolyzing (or ripening) the product to form secondary cellulose acetate; wherein the catalyst in the acetylated mixture is completely neutralized before about the middle of the hydrolysis reaction at the latest and thereafter hydrolysis is carried out at a temperature of about 110.degree. to 120.degree. C. while maintaining the concentration of acetic acid in the reaction mixture at about 67 to 78% by weight based on the total weight of the acetic acid and water, the relation between the hydrolysis temperature and the concentration of acetic acid being defined by the area between and including points A, B, C and D in FIG. 2.

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Yokohama, Japan

Yoshiyuki Ikemoto