Abstract: A polycarbonate diol comprising a repeating unit represented by the following formula (A) in a proportion of 0.1% by mass or more and 99.

Abstract: A polycarbonate diol containing a repeating unit represented by the specific formula (A) and a terminal hydroxyl group, wherein more than 0 mol % and not more than 3.0 mol % of the terminals thereof is an oxolane terminal represented by the specific formula (B).

Abstract: A polycarbonate diol which is useful as a raw material compound for producing a polycarbonate-based polyurethane having a sufficient mechanical strength and excellent in a balance of physical properties such as oil resistance, hydrolysis resistance, and weather resistance and which is amorphous. The polycarbonate diol includes repeating units of the below-shown formula (A) and the below-shown formula (B), wherein both terminal groups are hydroxyl groups, the ratio of the below-shown formula (A) to the below-shown formula (B) is 99:1 to 1:99 by mol, and number-average molecular weight is 300 to 10,000.

Abstract: An object of the present invention is to provide a novel polycarbonate diol which is useful as a raw material compound for producing a polycarbonate-based polyurethane having a sufficient mechanical strength and excellent in a balance of physical properties such as oil resistance, hydrolysis resistance, and weather resistance and which is amorphous. The invention relates to a polycarbonate diol comprising repeating units of the below-shown formula (A) and the below-shown formula (B), wherein both terminal groups are hydroxyl groups, the ratio of the below-shown formula (A) to the below-shown formula (B) is 99:1 to 1:99 by mol, and number-average molecular weight is 300 to 10,000.

Abstract: A copolycarbonate diol comprising: (a) recurring units each represented by the following formula (1): (b) recurring units each independently represented by the following formula (2): wherein n is 4, 5 or 6; and (c) terminal hydroxyl groups, wherein the copolycarbonate diol has a number average molecular weight of from 300 to 20,000, and wherein the amount of the recurring units (a) is from 10 to 90% by mole, based on the total molar amount of the recurring units (a) and (b). A thermoplastic polyurethane obtained by copolymerizing the above-mentioned copolycarbonate diol with a polyisocyanate.

Abstract: A copolycarbonate diol comprising:

Abstract: Disclosed is a method for producing a diol mixture comprising 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol, which comprises: (A) providing a dicarboxylic acid mixture comprising succinic acid, glutaric acid and adipic acid and having a nitric acid content of 3% by weight or less, based on the total weight of the succinic, glutaric and adipic acids, wherein the dicarboxylic acid mixture is prepared by denitrating an aqueous by-product solution obtained in an adipic acid production process, and (B) subjecting the dicarboxylic acid mixture to hydrogenation in the presence of water, hydrogen gas and a hydrogenation catalyst containing an active metal species comprising ruthenium and tin, to thereby obtain a hydrogenation reaction mixture comprising a diol mixture comprising 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol.

Abstract: Disclosed is a catalyst for hydrogenating a carboxylic acid, comprising an activated carbon having carried thereon an active metal species comprising ruthenium and tin, wherein the activated carbon is produced by subjecting a carbonaceous material to activation treatment using zinc chloride, followed by calcination. Also disclosed is a catalyst for hydrogenating a carboxylic acid, comprising an activated carbon having carried thereon an active metal species comprising ruthenium and tin, wherein the activated carbon, prior to having carried thereon the active metal species, exhibits specific pore characteristics wherein, especially, the pore volume with respect to pores each having a radius of from 10 to 100 Å is from 0.5 to 2.0 cm3/g.