摘要:
A method for producing a polyether-polyol having a narrow molecular weight distribution, which comprises carrying out selective fractional extraction of the low-molecular weight component from a polyether-polyol (A) having an average molecular weight of from 500 to 4500 represented by formula (1): HO—[(CH2)4O]n—[(CR1R2)pO]q—H (1) wherein R1 and R2, which may be the same or different, each represents a hydrogen atom or a linear or branched alkyl group having from 1 to 5 carbon atoms; n indicates a positive integer; p indicates an integer of from 1 to 8; and q indicates 0 or a positive integer, by the use of an aqueous solution (C) containing from 15 to 70 wt % sulfuric acid at a room temperature to 100° C., to thereby suitably determine the amount of the aqueous sulfuric acid solution to the overall organic layer and the sulfuric acid concentration in accordance with the molecular weight and molecular weight distribution of the intended polyether-polyol to be fractionally extracted.
摘要:
Disclosed is a polyurethane resin having a broad rubbery-state region which has a number-average molecular weight of from 30,000 to 500,000 and comprises repeating units (A) represented by formula (I):--CONH-X-NHCOO-Y-O- (I)wherein X represents the divalent residue formed by removing the isocyanate groups from a specific aromatic diisocyanate and Y represents the divalent residue formed by removing the hydroxyl groups from a poly(alkylene ether) diol whose main chain is made up of the group represented by --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 O-- and a group represented by --CHR.sub.1 CHR.sub.2 CHR.sub.3 CHR.sub.4 O-- where one of R.sub.1, R.sub.2, R.sub.3, and R.sub.4 is a lower alkyl group and the remaining three each is a hydrogen atom, and which has a number-average molecular weight of from 500 to 10,000, and repeating units (B) represented by formula (II):--CONH-X-NHCOO-Z-O-- (II)wherein Z represents the divalent residue formed by removing the hydroxyl groups from 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5,5]undecane), the repeating units (A) and (B) being bonded together in a random sequence, with the proportion of (A)/(B) being from 0.1 to 2.0.
摘要:
A radiation-curable coating composition adapted for the coating of optical glass fiber, comprising an ethylenically unsaturated polyurethane which is the reaction product of:(A) a polyether diol having a molecular weight in the range of 200 to 8,000 and a structural unit represented by the formula: ##STR1## in which R.sup.1 -R.sup.4 are each independently selected from hydrogen and an alkyl group containing from 1-4 carbon atoms, such as a polymer of copolymer of methyl tetrahydrofuran;(B) a polyisocyanate compound, preferably a diisocyanate; and(C) a polymerizable ethylenically unsaturated compound having a single hydroxy group, such as a monohydric acrylate;there being employed per equivalent of hydroxy in component (C) from 1.1 to 2 equivalents of said polyisocyanate with the balance of the isocyanate groups being reacted waith the hydroxy groups of said diol.
摘要:
A polyurethane resin composition without handling trouble is obtained by a combination of a copolyether polyol obtained by copolymerization of tetrahydrofuran and a 3-alkyl tetrahydrofuran at a mixing molar ratio of 85/15-20/80, a polyisocyanate compound and an active hydrogen atom-containing compound. The 3-alkyl tetrahydrofuran is preferably 3-methyl tetrahydrofuran.
摘要:
A reagent for determination of hydrogen peroxide which comprises (A) a compound represented by the following general formula (I): R1—NH—R2 (I) (wherein R1 represents a carbamoyl group or the like, and R2 represents an arylamino group, a heteroarylamino group, or a substituent represented by the following general formula (II): [wherein R3 to R6 represent X—Y—Ra {Ra represents a hydrogen atom, an alkyl group or the like, X represents a single bond, O or the like, and Y represents a single bond, (C═O) or the like}, a cyano group, a halogen atom or the like]>; (B) a compound represented by the general formula (III): [wherein R9 represents a group which can be eliminated by oxidative coupling color-developing reaction with the compound represented by the formula (I), and R7, R8, and R10 to R13 have the same meaning as that of R3], or the like; and (C) a peroxidative substance.
摘要翻译:一种用于测定过氧化氢的试剂,其包含(A)由以下通式(I)表示的化合物:<?in-line-formula description =“In-line formula”end =“lead”?> 1-N-R 2(I)<?在线公式描述=“在线公式”end =“tail”?>(其中R 1, / SUP>表示氨基甲酰基等,R 2表示芳基氨基,杂芳基氨基或由以下通式(II)表示的取代基:[其中R 3 SUP>至R 6表示XYR a R i表示氢原子,烷基等,X表示单 键,O等,Y表示单键,(CO)等},氰基,卤素原子等〕;(B)由通式(III)表示的化合物:[ 其中R 9表示可以通过与式(I)表示的化合物的氧化偶联显色反应来除去的基团, R 7,R 8和R 10至R 13具有与R 10相同的含义, SUP> 3]等; 和(C)过氧化物质。