Pigmented polyester or polypropylene raw material - contg. pigment purified to reduce electrical conductivity, useful for capacitor film mfr

• Main Author: ULRICH BOLLERT ET WERNER DENNELER
• Format: Patent
• Language: English; French
• Published: 18.09.1981
• Subjects: BASIC ELECTRIC ELEMENTS; CABLES; CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES ORLIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE; CHEMISTRY; COMPOSITIONS BASED THEREON; CONDUCTORS; ELECTRICITY; INSULATORS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING ORDIELECTRIC PROPERTIES; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

Pigmented polymer raw material of (co)polyethylene terephthalate (PET) or (co)polypropylene contains a pigment (I) with a degree of purity of min. 99.0% as starting material, which is subjected to further purificn. operation(s) to reduce its electrical conductivity before addn. to the polymer. (I) is subjected to pressure filtration through a membrane filter and pref. to pressure and temp. treatment before further purificn. Purificn. can be carried out in water or, for use in (co)PET, in the same glycol(s) as used in polymer mfr. Further purificn. is carried out several times with addn. of fresh dispersants which do not or scarcely conduct electricity, the dispersants being circulated through a layer of absorbent and sepd. from the latter by a suitable membrane before re-use. The absorbent is activated charcoal and/or pref. an ion exchanger which can be regneerated. Pressure and temp. treatment are carried out in the vapour phase or under reduced pressure, opt. with addn. of a small amt. of inert gases. L'INVENTION EST RELATIVE A UNE MATIERE POLYMERE BRUTE PIGMENTEE DE TEREPHTALATE DE POLYETHYLENE, DE COPOLYMERES DE TEREPHTALATE DE POLYETHYLENE, DE POLYPROPYLENE OU DE COPOLYMERES DE POLYPROPYLENE, CARACTERISEE EN CE QU'ELLE CONTIENT UN PIGMENT PRESENTANT AU DEPART UN DEGRE DE PURETE EGAL OU SUPERIEUR A 99,0 ET QUI A ETE, PREALABLEMENT A SON ADDITION AU POLYMERE, SOUMIS A AU MOINS UN TRAITEMENT DE PURIFICATION COMPLEMENTAIRE POUR OBTENIR UNE DIMINUTION DE LA CONDUCTIBILITE ELECTRIQUE.ELLE CONCERNE EGALEMENT UN PROCEDE DE FABRICATION ET L'UTILISATION D'UNE TELLE MATIERE.