Isonova Technische Innovationen Ges.m.b.h.

Isovolta- Osterreichische Isolierstoffwerke Aktiengesellschaft

Isovolta Osterreichische Isolierstoffwerke

Isonova Technische Innovationen G.m.b.h

Peter Fialla

Aromatic-polyester molded article comprising a translucent,

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. The compounds involved in the polycondensation reaction are mixed in the dispesion unit in constant proportions in order to produce a reaction emulsion which then passes successively through one or several dispersion units and/or into static mixers, the polycondensation taking place and being completed during this period. The phases are then separated and the polyester formed is precipitated from the organic phase.

Process for the production of aromatic polyesters

Process for synthesizing 9,9-bis-(hydroxyphenyl)fluorene

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.

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Maria Enzersdorf, Austria

Peter Fialla