Abstract: Polyesters having a narrow molecular weight distribution and block copolymers having a narrow molecular weight distribution obtained from said polyesters can be produced by using a catalyst system comprising an aluminum porphyrin complex and an organic quaternary salt under mild reaction conditions.

Abstract: An aluminum atom- and monocarboxylic acid residue-containing polyester is provided. Using the polyester as an adhesive or a base, laminates and laminated hollow vessels which comprise, as the constituent elements, the polyester and an ethylene-vinyl alcohol copolymer can be produced. The laminates and laminated hollow vessels are suitable for use as packaging materials or containers for food and drink.

Abstract: The use of aluminum sulfate as a dessicant for drying the starting materials used in polymerization reactions employing readily hydrolyzable catalysts is disclosed. The aluminum sulfate is allowed to remain in the reaction mixture during polymerization, and, indeed, may advantageously be allowed to remain in the reaction product without any deleterious effect.

Abstract: Novel resin products produced by reacting unique polycyclic, aromatic, polycarboxylic acid products with low molecular weight polyols display satisfactory toughness properties and good Barcol hardness values. The process for preparing these novel resin products first involves preparing an intimate, finely divided mixture comprising the acid product derived from the nitric acid oxidation of naturally occurring solid carbonaceous material, a roughly equivalent amount of a liquid polyol, and a suitable acid catalyst. The mixture is then subjected to a precure step which involves heating at temperatures between 80.degree. and 150.degree. C. for from about fifteen minutes to about four hours. The precured mixture may thereafter be subjected to suitable molding conditions at a temperature below about 220.degree. C.

Abstract: A process for preparing polyesters having superior thermal stability, transparency and chemical resistance, which comprises (1) a first step of esterifying (A) a difunctional carboxylic acid containing at least 60 mole% of an aromatic dicarboxylic acid, (B) 0 to 80 mole%, based on component (A), of an aliphatic diol and/or a dihydroxybenzene and (C) an aromatic monohydroxy compound in an amount of at least 210 mole% as a total of it and component (B) based on component (A), the esterification being performed until the degree of esterification reaches at least 80%, (2) subsequently, a second step of adding 0 to 80 mole%, based on component (A), of component (B) and a bisphenol (D) in an amount of 100 to 130 mole% as a total of it and component (B) based on component (A) to the reaction product obtained in the first step and reacting the mixture, the total amount of components (B) used in the first and second steps being 0 to 80 mole% based on component (C), and (3) performing at least the first of the above st