Abstract: The present invention provides a process for producing polyhydroxycarboxylic acids which comprises subjecting at least one hydroxycarboxylic acid or oligomer thereof to polycondensation in the presence of an alkali metal compound, an alkaline earth metal compound, or a compound of a metal of Group IIIb of the periodic table. The polyhydroxycarboxylic acids obtained by the process have a weight-average molecular weight of 30,000 or above and are useful as biodegradable plastics for food-wrapping films, drug delivery systems, etc.

Abstract: The present invention provides a process for producing polyhydroxycarboxylic acids which have a weight-average molecular weight of 50,000 or above and which are excellent as biodegradable plastics by polycondensing hydroxycarboxylic acids or oligomers thereof in the presence of an inorganic solid acid catalyst in combination with an alkali metal or an alkaline earth metal.

Abstract: The present invention provides a process for producing polyhydroxycarboxylic acids having a weight-average molecular weight of 50,000 or above which are excellent as biodegradable plastics by subjecting Lactides to ring-opening polymerization in the presence of an inorganic solid acid catalyst carrying silica and/or a light metal.

Abstract: A leather modifier containing a compound which is obtainable through a reaction of an ethylene oxide derivative having a fluorine-containing group with a phosphorus compound is disclosed. A leather treated with the modifier has much improved properties.

Abstract: A termiticide comprising, as an active ingredient, a polymer which comprises repeating units of the formula:--C.sub.x F.sub.2x O--wherein x is an integer of 1 to 4, or the formula:--CX.sub.1 X.sub.2 CF.sub.2 CF.sub.2 O--wherein X.sub.1 and X.sub.2 are the same or different and each a hydrogen atom, a fluorine atom or a chlorine atom, provided that X.sub.1 and X.sub.2 are not fluorine atoms simultaneously, and has at least one polar group at polymer chain ends, which has no or little toxicity on the human beings or animals and long-lasting termiticidal effects.

Abstract: A tanned leather treated with a fatliquoring agent in combination with a fluorine-containing oil, which has good touch, water resistance, water- and oil-repellency, washing resistance, and which is not discolored or faded by dry cleaning.

Abstract: A magnetic core material made of a Fe-Co base alloy for use at high frequencies, and has excellent high-frequency alternating magnetic properties. The core material composition is Co: 45-53% by weight, C: 0.3-3% by weight, one or both of Mn and Si: 0.1-2% by weight, at least one of Mg, Ca, and Ce: 0.1-0.2% by weight, and the remainder Fe and unavoidable impurities. The structure of the alloy comprises a ferrite matrix containing graphite in an amount of from 1-20% by volume dispersed therein. The material is applied, for example, in a dot impact printer and to a pulse motor.

Abstract: A fluorine-containing polyether of the formula:A--X--A'wherein A and A' are the same or different and are each --COF, --COCl or --COOH, and X is --CF.sub.2 CF.sub.2 --R.sub.f --O--C.sub.m F.sub.2m --O--R.sub.f 'CF.sub.2 CF.sub.2 -- in which R.sub.f and R.sub.f ' are the same or different and are each a group containing a perfluoroalkylpolyether group, and m is a number of from 1 to 6, and a fluorine-containing polyether of the formula:Z--X.sub.n --Z'wherein X is the same as defined above, Z and Z' are the same or different and are each --COF, --COCl, --COOH or --CF.sub.2 CF.sub.2 --R.sub.f --B in which R.sub.f is the same as defined above and B is a fluorine atom or a C.sub.1 -C.sub.5 perfluoroalkyl group, and n is a number of from 0 to 100 provided that when n is 1, Z and Z' are each --CF.sub.2 CF.sub.2 R.sub.f B, provided that when n is 0, both Z and Z' are each --CF.sub.2 CF.sub.2 R.sub.f B or when n is 1, at least one of Z and Z' is --CF.sub.2 CF.sub.2 R.sub.f B.