Abstract: A process for producing diaryl carbonate of the present invention comprises steps of: (1) a diaryl carbonate production step of subjecting an aromatic monohydroxy compound and phosgene to condensation reaction at a temperature of 80 to 180° C. in the presence of an aromatic nitrogen-containing heterocyclic compound catalyst to obtain the diaryl carbonate; (2) a purification step of removing impurities from a hydrogen chloride gas by-produced upon the condensation reaction; (3) a chlorine recovery step of recovering chlorine usable for the production of phosgene from the purified hydrogen chloride gas; and (4) a phosgene production step of reacting the recovered chlorine with carbon monoxide to obtain phosgene usable in the diaryl carbonate production step.

Abstract: A process for producing diaryl carbonate of the present invention comprises steps of:

Abstract: A polycarbonate resin obtained by reacting a carbonate raw material with a dihydroxy compound, having: a ratio (Mw/Mn) of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn) of not more than 2.2:1, calculated as polystyrene, when measured by gel permeation chromatography; and a ratio (Mv/Mn′) of a viscosity-average molecular weight (Mv) calculated according to the following formulae, to a number-average molecular weight (Mn′) calculated based on the number of molecular ends, of not more than 1.40:1. &eegr;sp/C=[&eegr;]×(1+0.28&eegr;sp) [&eegr;]=1.23×10−4×(Mv)0.83 wherein &eegr;sp is a specific viscosity of the polycarbonate resin when measured with respect to a methylene chloride solution thereof at 20° C.; and C is a concentration of the methylene chloride solution, in the present case, the methylene chloride solution having a polycarbonate resin concentration of 0.6 g/dl is used.

Abstract: The process for producing an aromatic polycarbonate of the present invention comprises subjecting an aromatic diol compound and a carbonic acid diester to transesterification reaction in the presence of a defoaming agent. In the process of the present invention, it is possible to produce a transparent and colorless aromatic polycarbonate having a high quality, at a high polymerization velocity without occurrence of significant foaming phenomenon.

Abstract: A polycarbonate resin having an improved hue is provided, which is suitable for use as a substrate for transfer type optical recording media such as optical disks.

Abstract: A polycarbonate resin having an improved hue is provided, which is suitable for use as a substrate for transfer type optical recording media such as optical disks.

Abstract: A polycarbonate resin obtained by polymerizing an aromatic diol and a carbonate-forming compound using a monophenolic compound as a molecular weight modifier, wherein said polycarbonate resin contains from 0.2 to 2% by weight of a low-molecular weight compound represented by formula (I): ##STR1## wherein R.sup.1 represents an aromatic diol residue; and R.sup.2 represents a monophenolic compound residue, and wherein said polycarbonate resin provides less amount of low-molecular weight volatile matters even when heated or injection-molded. When heated at 350.degree. C. under reduced pressure of 1 mmHg for 20 minutes, the proportion of the low-molecular weight compound of formula (I) which volatilizes is not more than 0.2% by weight based on the weight of said low-molecular weight compound of formula (I) present in the polycarbonate resin. When heated at 400.degree. C.

Abstract: There is provided a polycarbonate resin with a reduced volatile chlorine content in which the amount of a chlorinous matter as volatilized from the resin when the resin is heated at 280.degree. C. for 30 minutes and then allowed to stand at room temperature for 3 days is 30 ppb or lower as calculated in terms of the amount of Cl atom. There is also provided a process for producing a polycarbonate resin using phosgene as a raw material, the improvement comprising using phosgene having a chlorine concentration of up to 1,000 ppb as the raw material thereby to provide the resin with a reduced volatile chlorine content.

Abstract: Compounds of formula (I) and (II): ##STR1## ?wherein R is hydrogen, halogen or alkyl; R.sup.1 is alkyl, amino or substituted amino; R.sup.2 is optionally substituted phenyl; R.sup.3 is hydrogen, halogen or optionally substituted alkyl; R.sup.4 is hydrogen, optionally substituted alkyl, cycloalkyl, aryl, or aralkyl! have valuable analgesic, anti-inflammatory, anti-pyretic and anti-allergic activities and have the ability to inhibit the production of leukotrienes and to inhibit bone resorption. They are relatively free from the side effects which generally result from the administration of compounds having these kinds of activities.

Abstract: Compounds of formula (I): ##STR1## where R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are hydrogen or alkyl and R.sup.3 is hydrogen, alkyl or various organic groups are effective against osteoporosis at doses at which they also effectively control diabetes.

Abstract: Disclosed are a method for producing a polyamide resin which comprises the steps of extracting with water a polyamide resin obtained by polymerizing caprolactam in the presence of water; condensing the extracted aqueous solution containing unreacted caprolactam and its low polymerized materials; and polymerizing the condensate by adding an additional amount of caprolactam, the improvement wherein(a) among the low polymerized materials of caprolactam, a cyclic dimer is supplied to a polymerization reactor after subjecting it to ring-opening reaction to give a chain structure material in an amount of 15% by weight or more based on the total amount of the cyclic dimer, or(a') a condensate obtained by condensing said aqueous solution until reaching a water partial pressure of 10 kg/cm.sup.2 G or more and a temperature of 230.degree. C.

Abstract: A random copolymerized polyamide resin is prepared by reacting a lactam of the formula (I): ##STR1## wherein R.sup.1 is a C.sub.2-11 alkylene group optionally substituted with a substituent having 1 to 6 carbon atoms, with a hexamethylenediamine-adipic acid salt while concentrating the aqueous solution of the salt to a concentration of at least 70% by weight and while maintaining a uniform reaction phase at all times by controlling the pressure over and the temperature of the reaction medium such that the hexamethylenediamine-adipic acid salt does not precipitate, said pressure being up to not greater than 2 kg/cm.sup.2 .multidot.G and said temperature being up to not greater than 150.degree. C., and then mixing in the solution of the lactam of formula (I) thereby effecting copolymerization and forming a polyamide resin having a relative viscosity measured by the sulfuric acid solution method (1% at 25.degree. C.) of 1.5 to 8.0.

Abstract: A method of treating a PAF-mediated pathology or for treating or preventing psoriasis, nephritis, asthma, inflammation or shock by administering an effective amount of a PAF antagonist of the formula ##STR1## wherein R.sup.1 and R.sup.2 are each --R.sup.5, --CH.dbd.CH--R.sup.5 or --C.tbd.C--R.sup.5 ; R.sup.5 is an unsubstituted or substituted C.sub.6 -C.sub.14 carbocyclic aryl of an aromatic heterocyclic having from 5 to 14 ring atoms, of which from 1 to 5 are hetero-atoms selected from the group consisting of nitrogen, oxygen and sulfur, the heterocyclic group being unsubstituted or substituted; R.sup.3 is hydrogen, a C.sub.1 -C.sub.6 alkyl, cyano, or --R.sup.5 ; X is oxygen or sulfur; A is a 1,4-piperazin-1,4-diyl or a 1,4-homopiperazin-1,4-diyl; B is a C.sub.1 -C.sub.6 alkylene, carbonyl, thiocarbonyl, sulfinyl or sulfonyl; and R.sup.4 is an unsubstituted or substituted phenyl group.

Abstract: Compounds of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 is each --R.sup.5, --CH.dbd.CH--R.sup.5 or --C.tbd.C--R.sup.5, wherein R.sup.5 is optionally substituted aryl or aromatic heterocyclic; R.sup.3 is hydrogen, alkyl, cyano or --R.sup.5 ; X is oxygen or sulfur A is 1,4-piperazin-1,4-diyl or a 1,4-homopiperazin-1,4-diyl; B' is alkylene, carbonyl, thiocarbonyl, sulfinyl or sulfonyl: and R.sup.4 is optionally substituted phenyl and pharmaceutically acceptable salts thereof have valuable PAF antagonist activity.

Abstract: Compounds of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 is each --R.sup.5, --CH.dbd.CH--R.sup.5 or --C.tbd.C--R.sup.5, wherein R.sup.5 is optionally substituted aryl or aromatic heterocyclic; R.sup.3 is hydrogen, alkyl, cyano or --R.sup.5 ; X is oxygen or sulfur; A a 1,4-homopiperazin-1,4-diyl; B' is alkylene, carbonyl, thiocarbonyl, sulfinyl or sulfonyl; and R.sup.4 is optionally substituted phenyl and pharmaceutically acceptable salts thereof have valuable PAF antagonist activity, and may be prepared by reacting a compound containing the homopiperazine part of the molecule with a compound containing the other part of the molecule.

Abstract: The present invention relates to an extraction/insertion type soot blowing apparatus in which a lance tube is inserted into a combustion chamber, and a high-pressure gas is blown from a nozzle provided at the tip end of the lance tube against a deposit adhered onto the inner surface of the combustion chamber to remove the deposit. A rack adapted to be advanced and withdrawn along with the lance tube, and a long shaft for rotating the lance tube, are driven due to connection thereof with two output shafts of a differential gear device, and rotation and linear motion of the lance tube are respectively restrained within predetermined ranges. Thereby, at first the lance tube is inserted into the combustion chamber at a high speed without being rotated, and thereafter the advance is stopped and a gas is discharged while the lance tube is being rotated.

Abstract: Compounds of formula (I): ##STR1## wherein R.sup.1 and R.sup.2 is each --R.sup.5, --CH.dbd.CH--R.sup.5 or --C.tbd.C--R.sup.5, wherein R.sup.5 is optionally substituted aryl or aromatic heterocyclic; R.sup.3 is hydrogen, alkyl, cyano or --R.sup.5 ; X is oxygen or sulfur; A is 1,4-piperazin-1,4-diyl or a 1,4-homopiperazin-1,4-diyl; B' is alkylene, carbonyl, thiocarbonyl, sulfinyl or sulfonyl; and R.sup.4 is optionally substituted phenyl and pharmaceutically acceptable salts thereof have valuable PAF antagonist activity, and may be prepared by reacting a compound containing the piperazine or homopiperazine part of the molecular with a compound containing the other part of the molecule.

Abstract: A new compound, which we have named "Leualacin" has the formula (I): ##STR1## and may be prepared by cultivation of a microorganism of the genus Hapsidospora, especially Hapsidospora irregularis. The compound may be used for the treatment and prophylaxis of cardiovascular diseases and disorders, especially hypertension.

Abstract: A method for producing a block copolyamide, which comprises polycondensing a prepolymer prepared from a dimerized fatty acid and a diamine and having a number average molecular weight of from 1,000 to 50,000, with a polyamide material other than said prepolymer component or a prepolymer thereof.

Abstract: Disclosed herein is a process for producing a polyamide comprising polymerizing at least one monomer of polyamide in the presence of(1) a hydrocarbon polymer having at least one group selected from the group consisting of a carboxyl group, a derivative group of carboxylic acid, an amino group, and a hydroxyl group, or(2) a polymer produced by reacting the hydrocarbon polymer with a polyamide, or polymerizing at least one monomer of polyamide in the presence of the hydrocarbon polymer.