Abstract: An object of the present invention is to provide a process which can produce, easily and with good productivity and reproducibility, an ethylene oxide copolymer provided with desired compositional ratios of monomers and a desired molecular weight and further with a desired melting point. As a means of achieving this object, a process according to the present invention for production of an ethylene oxide copolymer is a process comprising a step of polymerizing a monomer mixture including ethylene oxide as a main component, thereby producing the ethylene oxide copolymer, with the process being characterized in that the polymerization step includes at least one step each of the following steps: a step in which only the ethylene oxide is supplied to thus polymerize it; and a step in which the ethylene oxide and another monomer are supplied to thus polymerize them.

Abstract: The present invention provides a production process, in which, when an ethylene oxide copolymer is obtained, conditions for obtaining this copolymer having a desirable molecular weight with ease and good reproducibility are provided. The production process for an ethylene oxide copolymer, according to the present invention, comprises the step of carrying out polymerization of a monomer mixture under stirring in a solvent, thereby obtaining the ethylene oxide copolymer, wherein the monomer mixture includes ethylene oxide and a substituted oxirane compound of a structural formula (1) as essential raw materials; with the production process being characterized in that the stirring is carried out by a stirring power of not less than 0.6 kW/m3.

Abstract: The present invention provides a production process, in which, when an ethylene oxide copolymer is obtained, conditions for obtaining this copolymer having a desirable molecular weight with ease and good reproducibility are provided. The production process for an ethylene oxide copolymer, according to the present invention, comprises the step of carrying out polymerization of a monomer mixture under stirring in a solvent, thereby obtaining the ethylene oxide copolymer, wherein the monomer mixture includes ethylene oxide and a substituted oxirane compound of a structural formula (1) as essential raw materials; with the production process being characterized in that the stirring is carried out by a stirring power of not less than 0.6 kW/m3.

Abstract: A process for producing a high-molecular-weight polydioxolane, which includes the steps of: polymerizing 1,3-dioxolane using a polymerization catalyst comprising a heteropolyacid and a ketone; and neutralizing the resulting polymerization reaction product using an organic amine and/or ammonia. A hydrophilic film, which includes a resin including a polydioxolane and having a particular molecular weight and has a particular crystallinity and a particular spherulite's size. A film crumbly in cold water is produced by forming a film under particular forming conditions from a resin including a polydioxolane and having a particular molecular weight, or by subjecting an already formed film to particular thermal hysteresis.

Abstract: This invention provides a process for producing with industrially good efficiency a polyester having a high melting point and biodegradability. In this process, ring-opening copolymerization of a cyclic acid anhydride containing succinic anhydride as a main component with a cyclic ether containing ethylene oxide as a main component is carried out in the presence of a catalyst by introducing successively the cyclic ether into a reaction vessel containing the cyclic acid anhydride in a melting state or solution state. The rate per hour of introducing the cyclic ether is within the range of 3 to 90 parts by weight per 100 parts by weight of the cyclic acid anhydride, and the reaction vessel has an inside pressure within the range of atmospheric pressure to 50 kgf/cm.sup.2 as a gauge pressure.