Abstract: This method for manufacturing a rotor core includes an injection step of injecting a molten resin material into a magnet housing portion of a laminated core heated to a third temperature by a preheating step. The injection step is a step of injecting the resin material into the magnet housing portion while releasing to the outside of the magnet housing portion a volatile organic compound volatilized by heating the resin material by bringing the resin material into contact with the laminated core heated to the third temperature.

Abstract: A rotor core includes a thermosetting resin material disposed in a magnet housing portion to fix a permanent magnet in the magnet housing portion. The resin material has a coefficient of linear expansion that is equal to or less than the coefficient of linear expansion of electromagnetic steel sheets.

Abstract: An object of the present invention is to provide a crystalline radically polymerizable composition for fixing a magnet of a rotating electric machine rotor core, which is excellent in handleability around room temperature, excellent in fluidity from the injection step to the curing step, and excellent in strength of the cured product. A crystalline radical polymerizable composition for fixing a magnet of a rotating electric machine rotor core of the present invention is characterized by fixing the magnet inserted in a magnet accommodating portion provided in a rotor core of a rotating electric machine formed of a laminated steel sheet and the laminated steel sheet, wherein the crystalline radical polymerizable composition contains at least a crystalline radical polymerizable compound A, an inorganic filler B, a silane coupling agent C, and a radical polymerization initiator D, wherein the crystalline radical polymerizable compound A is solid at 23° C.

Abstract: [Problems] An object of the present invention is to provide a crystalline radical polymerizable composition which is excellent in flowability and is easy to handle. [Solution Means] The crystalline radical polymerizable composition for sealing electrical and electronic component according to the present invention is characterized by comprising at least a crystalline radical polymerizable compound, an inorganic filler, a silane coupling agent, and a radical polymerization initiator. In addition, in a preferred embodiment of the crystalline radical polymerizable composition for sealing electrical and electronic component according to the present invention, the crystalline radical polymerizable compound is characterized by comprising one or more selected from unsaturated polyester, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, -polyether (meth) acrylate, radical polymerizable monomer and radical polymerizable polymer.

Abstract: [Problems] An object of the present invention is to provide a crystalline radical polymerizable composition which is excellent in flowability and is easy to handle. [Solution Means] The crystalline radical polymerizable composition for sealing electrical and electronic component according to the present invention is characterized by comprising at least a crystalline radical polymerizable compound, an inorganic filler, a silane coupling agent, and a radical polymerization initiator. In addition, in a preferred embodiment of the crystalline radical polymerizable composition for sealing electrical and electronic component according to the present invention, the crystalline radical polymerizable compound is characterized by comprising one or more selected from unsaturated polyester, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, -polyether (meth) acrylate, radical polymerizable monomer and radical polymerizable polymer.

Abstract: The purpose of the present invention is to provide a crystalline unsaturated polyester resin composition which has improved fluidability upon being mixed with an inorganic filler, a white pigment or the like. A crystalline unsaturated polyester resin composition for an LED reflector according to the present invention is a crystalline unsaturated polyester resin composition comprising at least a crystalline unsaturated polyester resin and an inorganic filler, and is characterized in that the crystalline unsaturated polyester resin comprises a crystalline unsaturated polyester and a copolymerizable monomer and/or a copolymerizable prepolymer and the crystalline unsaturated polyester resin composition contains a white pigment. A preferred embodiment of the crystalline unsaturated polyester resin composition for an LED reflector according to the present invention is characterized in that the crystalline unsaturated polyester resin has a solid state in a temperature range that does not exceed 50° C.

Abstract: In the invention, a polyester resin comprising dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process comprising an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a basic compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.

Abstract: In the invention, a polyester resin having dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process including an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a titanium compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.

Abstract: In the invention, a polyester resin having dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process including an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a titanium compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.

Abstract: In the invention, a polyester resin comprising dicarboxylic acid constitutional units and diol constitutional units wherein 5 to 60 mol % of the diol constitutional units has a cyclic acetal skeleton is produced by a process comprising an oligomerization step and a polymerization step. In the oligomerization step, an ester having a limited acid value is transesterified with a diol having a cyclic acetal skeleton in the presence of a basic compound to obtain an oligomer. The oligomer is then polymerized in the subsequent polymerization step to increase the molecular weight.

Abstract: The process of the present invention for producing a polyester resin comprising a dicarboxylic acid constitutional unit and a diol constitutional unit having a cyclic acetal skeleton comprises a step (1) of subjecting a diol (A) having a cyclic acetal skeleton and an ester (D) to transesterification reaction and a step (2) of mainly converting the resultant oligomer into a high polymer. The step (1) simultaneously satisfies the requirements (i) to (iv) as described in the specification. In the process of the present invention, the polyester resins having excellent moldability and mechanical properties are stably produced by a transesterification method which is less detrimental to environments.

Abstract: The process of the present invention for producing a polyester resin comprising a dicarboxylic acid constitutional unit and a diol constitutional unit having a cyclic acetal skeleton comprises a step (1) of subjecting a diol (A) having a cyclic acetal skeleton and an ester (D) to transesterification reaction and a step (2) of mainly converting the resultant oligomer into a high polymer. The step (1) simultaneously satisfies the requirements (i) to (iv) as described in the specification. In the process of the present invention, the polyester resins having excellent moldability and mechanical properties are stably produced by a transesterification method which is less detrimental to environments.