Abstract: A plasticizer for a vinyl chloride resin with excellent balance of non-transfer properties, fogging resistance, flexibility, heat resistance, and cold resistance is provided. Specifically, a plasticizer for a vinyl chloride resin is a polyester made from a glycol having 2 to 18 carbon atoms, an aliphatic dicarboxylic acid having 4 to 14 carbon atoms, and a monoalcohol having 4 to 18 carbon atoms and/or a monocarboxylic acid having 2 to 21 carbon atoms, as reaction raw materials, in which the polyester has a number average molecular weight in a range of 500 to 6,000 and contains components with a molecular weight of 600 or less in a range of 0.5 to 3.0% by mass in terms of area ratio in gel permeation chromatography measurement.

Abstract: Provided is a plasticizer which can impart excellent heat resistance to a molded article of a vinyl chloride resin composition. Specifically, provided is a plasticizer for vinyl chloride resin, wherein the plasticizer is a polyester represented by the following formula (1) or (2), wherein, in the formulae (1) and (2), B11 represents an aliphatic monocarboxylic acid residue having 7 to 20 carbon atoms, B12 represents an aliphatic monocarboxylic acid residue having 7 to 20 carbon atoms, B21 represents an aliphatic monoalcohol residue having 6 to 10 carbon atoms, B22 represents an aliphatic monoalcohol residue having 6 to 10 carbon atoms, G represents an alkylene glycol residue having 3 to 10 carbon atoms or an oxyalkylene glycol residue having 3 to 10 carbon atoms, A represents an alkylenedicarboxylic acid residue having 6 to 12 carbon atoms, and each of m and n represents the number of repeating units in parentheses.

Abstract: An object of the present invention is to provide a method for producing porous silica particles having a small particle diameter in high yield relative to a volume of a reaction solution. In order to achieve the object, the present invention provides a method for producing porous silica particles having pores on the surfaces thereof, the method including a step of adding a mixed solution (solution A) containing tetraalkoxysilane, alkylamine, and alcohol to a mixed solution (solution B) containing ammonia, alcohol, and water and performing a hydrolysis and condensation reaction of the tetraalkoxysilane to produce silica particles, and a step of removing the alkylamine from the silica particles.