Abstract:
A mixture of an isomer of 2,2'-azobis(2,4-dimethylvaleronitrile) having a low melting point in an amount of about 70% by weight or more and an isomer of 2,2'-azobis(2,4-dimethylvaleronitrile) having a high melting point in an amount of about 30% by weight or less shows excellent solvent solubility, which is higher than that of the isomer having a low melting point. The mixture is useful as a polymerization initiator, and also as a blowing agent.
Abstract:
A polymer or copolymer of lactic acid and/or glycolic acid which has a weight-average molecular weight of not less than about 5,000 and a dispersity of about 1.5 to 2 is advantageously used as a biodegradable polymer or copolymer for medical preparation.
Abstract:
Water-soluble polymers having high molecular weight with little branching and good water solubility, particularly acrylamide series polymers having excellent flocculation effect can be obtained when 2,2'-azobis-(N,N'-dimethyleneisobutylamidine) or an acid addition salt thereof or a mixture of 2,2'-azobis(N,N'-dimethyleneisobutylamidine) or an acid addition salt thereof and another azo compound is used as polymerization initiator.
Abstract:
Cyclic azoamidine compounds having the formula and salts thereof are disclosed. ##STR1## wherein R denotes a methyl group or an ethyl group, and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently denote a lower alkyl group having one to four carbon atoms or a hydrogen atoms, provided that a case where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are all hydrogen atoms is excluded. The cyclic azoamidine compounds and their salts are useful as polymerization initiators in the production of polymer compounds.
Abstract:
A copolymer of lactic acid and glycolic acid which has a weight-average molecular weight of not less than about 5000 and a dispersity of about 1.5 to 2 is advantageously used as a biodegradable polymer for medical preparation.
Abstract:
2.alpha.-Methyl-2.beta.-(1,2,3-triazol-1-yl)methylpenam-3.alpha.-carboxylic acid derivatives are prepared by reacting a penicillanic acid sulfoxide derivative of the formula ##STR1## wherein R is a penicillin carboxyl protecting group, and R.sub.1 is hydrogen or halogen, R.sub.2 is hydrogen, lower alkyl or the like with a triazole derivative of the formula ##STR2## wherein R.sub.3 and R.sub.4 are hydrogen, trialkylsilyl, lower alkyl, lower alkoxy or the like and R.sub.5 is hydrogen or silyl substituted with 3 groups selected from the class consisting of lower alkyl, benzyl and phenyl in a solvent.
Abstract:
An improved process for preparing oxytitanium phthalocyanine is provided wherein the condensation reaction of o-phthalodinitrile with titanium tetrachloride is effected in an organic solvent at 170.degree. to 300.degree. C. followed by hydrolysis, the improvement wherein said organic solvent is preliminarily heated at a temperature of 160.degree. to 300.degree. C. prior to initiation of the condensation reaction. The A form of oxytitanium phthalocyanine crystal can selectively be produced in the pure state.
Abstract:
A silver halide photosensitive material comprising a support, a silver halide photosensitive layer, and a protective layer formed on said support. The protective layer is essentially composed on a plurality of non-photosensitive hydrophilic colloidal layers at least one of which contains oil particles. The outermost layer of the hydrophilic colloidal layers contains a matting agent in the form of colloidal particles and has a thickness of not more than one fourth of the average size of the matting agent particles and wherein the density of the oil particles in said outermost layer does not exceed 0.2 by volume of the binder, and that of the oil particles in the protective layers other than the outermost layer is in the range of 0.1 to 0.8.
Abstract:
To provide a compound which exhibits excellent anti-tumor activity and excellent oral absorption and which is a useful anti-tumor drug.The invention provides a 3′-ethynylcytidine derivative represented by formula (1): (wherein X represents a (substituted) alkylcarbonyl group, a (substituted) alkoxycarbonyl group, or a hydrogen atom; one of Y and Z represents a hydrogen atom or a group represented by (R1)(R2)(R3)Si— and the other represents a group represented by (R4)(R5)(R6)Si—; and R1, R2, R3, R4, R5, and R6 each represent a (substituted) alkyl group, a (substituted) cyclic alkyl group, or a (substituted) aryl group) or a salt thereof.
Abstract:
To provide a compound which exhibits excellent anti-tumor activity and excellent oral absorption and which is a useful anti-tumor drug.The invention provides a 3′-ethynylcytidine derivative represented by formula (1): (wherein X represents a (substituted) alkylcarbonyl group, a (substituted) alkoxycarbonyl group, or a hydrogen atom; one of Y and Z represents a hydrogen atom or a group represented by (R1)(R2)(R3)Si— and the other represents a group represented by (R4)(R5)(R6)Si—; and R1, R2, R3, R4, R5, and R6 each represent a (substituted) alkyl group, a (substituted) cyclic alkyl group, or a (substituted) aryl group) or a salt thereof.