Abstract: A polyolefin resin composition consisting essentially of at least one homopolymer or copolymer of an aliphatic monoolefin and 0.05 to 2% by weight, based on the weight of the composition, of a dibenzylidene sorbitol derivative of the following formula ##STR1## wherein R and R' are different from each other and each represents a member selected from the class consisting of a hydrogen atom, a chlorine atom, alkyl groups having 1 to 3 carbon atoms and alkoxy groups having a C.sub.1 -C.sub.3 alkyl moiety.

Abstract: An acrylic resin article comprising a methyl methacrylate polymer and dibenzylidene sorbitol or its derivative as essential ingredients; and a process for producing an acrylic resin article, which comprises putting a composition comprising a methyl methacrylate monomer or a mixture of a methyl methacrylate polymer and a methyl methacrylate monomer and dibenzylidene sorbitol or its derivative in a mold, and thereafter polymerizing the methyl methacrylate monomer in the composition.

Abstract: A composition consisting essentially of solid powdery dibenzylidene sorbitol and a higher fatty acid, the surface of the dibenzylidene sorbitol being coated with the higher fatty acid; and a process for producing dibenzylidene sorbitol powder having a coating of a higher fatty acid on its surface, which comprises a step of forming an aqueous emulsion of the higher fatty acid by adding an alkali to an organic solvent solution or hot molten mass of the higher fatty acid partially saponify the higher fatty acid and dispersing the resulting mixture of the higher fatty acid and its saponification product in water, a step of coating the surface of dibenzylidene sorbitol powder with the higher fatty acid by adding the dibenzylidene sorbitol to the resulting emulsion, and a step of separating the solid from the mixture, drying the solid and recovering the dried product. The transparency and rigidity of a polyolefin resin is improved by addition of aforesaid dibenzylidene sorbitol composition.

Abstract: In a process for preparing dibenzylidenesorbitol by dehydrocondensation of 1 mol of sorbitol with 2 mols of benzaldehyde in the presence of an acid catalyst, the improvement in which the reaction is carried out in two stages, the first-stage reaction comprising reacting the reactants with heating at a temperature of 50.degree. to 70.degree. C., the first-stage reaction being shifted to the second-stage reaction by adding water and an additional amount of an acid catalyst when the conversion of sorbitol to dibenzylidenesorbitol reaches 10 to 40%, and the second-stage reaction comprising of reacting the mixture in the suspended state at ordinary temperature in 2.5 or more parts by weight, per part by weight of sorbitol, of an aqueous reaction medium, and the resulting dibenzylidenesorbitol is obtained as an aqueous suspension.

Abstract: Purified dibenzylidene sorbitol is prepared by mixing crude dibenzylidene sorbitol containing monobenzylidene sorbitol and tribenzylidene sorbitol as by-product impurities with a lower aliphatic alcohol to dissolve the impurities, and separating and recovering the undissolved dibenzylidene sorbitol. This process affords dibenzylidene sorbitol having a purity of at least 98% from crude dibenzylidene sorbitol with a purity of about 95%.