Abstract: Translucent, pore-free sintered aromatic polyesters made from diphenols such as 1,1-bis(4-hydroxyphenyl)fluorene and phthalic-acid halides evince one or more glass transition points in the range of 220.degree. to 400.degree. C. and a tensile strength larger than 40 N/mm.sup.2 but advantageously larger than 60 N/mm.sup.2. They also evince higher resistance to some solvents such as carbon tetrachloride when in the form of poured films as regards the same material. To manufacture the sintered article, the polyester powder is subjected in a closed mold to a pressure larger than 3,000 N/cm.sup.2, the mold meantime being slowly heated and then kept for an appreciable time above the glass transition point and thereupon being slowly cooled. As a rule the sintered articles are used as semi-finished products or as pre-formed component-blanks from which the desired end products are made by mechanical cutting.

Abstract: In a continuous process for the manufacture of aromatic polyesters by polycondensation of mono- or multi-nuclear substituted or unsubstituted diphenols, with halides of aromatic dicarboxylic acids according to the two-phase interface polycondensation process, the first step is to produce continuously a fine pre-emulsion with an organic solvent and from the aqueous phase, consisting of a solution obtained from the diphenols, of an alkaline hydroxide in order to form the diphenates and possibly of a phase transfer catalyst in water or in a mixture of water and of an organic solubilizer. This pre-emulsion is fed in quantities to a dispersion unit jointly with the organo-liquid phase forming the acid chloride solution.

Abstract: The invention concerns a process for synthesizing 9,9-bis(hydroxyphenyl)fluorene by reacting fluorene with excess phenol using a liquid catalyst prepared by dissolving aluminum trichloride in an anhydrous organic solvent such as toluene evincing the property of an electron donor while hydrochloric-acid gas is being supplied. For the purpose of the synthesis, the fluorenone is dissolved for instance at 60.degree. C. in the liquid phenol and then the liquid catalyst is dripped into the agitated reaction mixture at such a rate that the temperature of the reaction mixture is kept below 60.degree. C. Following catalyst addition and subsequent after-reaction interval of several hours, the raw product is mixed with hot water and the excess phenol is removed by steam distillation. After signle-washing with water, the raw product is dissolved in hot acetone, allowed to crystallize, is filtered out and dried in vacuum. Lastly the raw product is recrystallized from 1,2-dichloroethane to form the pure product.

Abstract: Sintered bodies made of aromatic polyesters prepared from diphenols, such as 1,1-bis(4-hydroxyphenyl-1-phenylethane or 9,9-bis(4-hydroxyphenyl)fluorene, and halides of phthalic acid which have one or more glass transition temperatures in the range of 220.degree.-400.degree. C. and tensile strengths higher than 40 N/mm.sup.2, and advantageously higher than 60 N/mm.sup.2 are disclosed. To make the sintered bodies, polyester powder is exposed to high pressure within a closed mold and the temperature of the polyester powder is slowly increased by heating until a temperature higher than the glass transition temperature is reached, whereafter the polyester is slowly cooled. During the sintering process the polyester is crosslinked which results in an increased resistance against solvents. The sintered bodies of the invention are used in general as semi-finished products or preformed parts, which will be transformed to bodies with required shapes through subsequent machining.

Abstract: In a continuous process for the manufacture of aromatic polyesters by polycondensation of mono- or multi-nuclear substituted or unsubstituted diphenols, with halides of aromatic dicarboxylic acids according to the two-phase interface polycondensation process, the first step is to produce continuously a fine pre-emulsion with an organic solvent and from the aqueous phase, consisting of a solution obtained from the diphenols, of an alkaline hydroxide in order to form the diphenates and possibly of a phase transfer catalyst in water or in a mixture of water and of an organic solubilizer. This pre-emulsion is fed in quantities to a dispersion unit jointly with the organo-liquid phase forming the acid chloride solution.

Abstract: Electrically insulating wire coatings are resistant to prolonged exposure to 200.degree. C. when formed from a powder which, in a preferred composition, is a blend of(a) epoxy-terminated adduct of hydantoin diepoxide and aromatic dicarboxylic acid imide dissolved in hydantoin diepoxide,(b) acid-terminated polyester of aromatic dicarboxylic acid and diphenol containing one aromatic ring pendant from a central carbon atom,(c) bismaleimide, and(d) fumaric acid.

Abstract: Novel low-molecular weight polyesters consisting essentially of chain members of the formula ##STR1## wherein X is at least one member selected from the group consisting of ##STR2## and R is a bifunctional aliphatic hydrocarbon or a bifunctional hydrocarbon containing at least one aromatic or cycloaliphatic ring having an inherent viscosity of 0.08 to 0.35 dl/g measured at 30.degree. C. on a 100 ml solution of 0.5 g of polyester in a solvent of 60% by weight of phenol and 40% by weight of 1,1,2,2-tetrachloroethane useful for further polymerization with amines, amides, imides and a novel method of preparing the same.

Abstract: In a continuous process for the manufacture of aromatic polyesters by polycondensation of mono- or multi-nuclear substituted or unsubstituted diphenols, with halides of aromatic dicarboxylic acids according to the two-phase interface polycondensation process, the first step is to produce continuously a fine pre-emulsion with an organic solvent and from the aqueous phase, consisting of a solution obtained from the diphenols, of an alkaline hydroxide in order to form the diphenates and possibly of a phase transfer catalyst in water or in a mixture of water and of an organic solubilizer. This pre-emulsion is fed in quantities to a dispersion unit jointly with the organo-liquid phase forming the acid chloride solution.