PROCEDIMIENTO PARA PREPARAR RESINAS EPOXIDICAS MODIFICADAS QUE TIENEN UNA DISTRIBUCION DE PESOS MOLECULARES

• Main Authors: DIJKSTRA, TETTE JAN, STACHOWIAK, STEPHEN ANTHONY, JONGEPIER, WOUTER WILLEM, DECOCQ, FRANCOISE IRENE MARIE BERNADETTE
• Format: Patent
• Language: Spanish
• Published: 01.08.1996
• Edition: 6
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

UN PROCESO PARA PREPARAR UNA RESINA EPOXI MODIFICADA CON UNA DISTRIBUCION DE PESO MOLECULAR ENTRE 1.9 Y 4.5 Y UN CONTENIDO DE GRUPO EPOXI MENOR DE 200 MMOL/KG HACIENDO REACCIONAR A UNA TEMPERATURA DE ENTRE 135 Y 215 C UNA RESINA EPOXI AROMATICA CON UN CONTENIDO DE GRUPO EPOXI DE AL MENOS 250 MMOL/KG Y ENTRE 1.5 Y 2.2 GRUPOS EPOXI POR MOLECULA CON ENTRE 5 Y 170% DE EXCESO MOLAR DE UN COMPUESTO DIHIDROXI DE FORMULA; EN LA QUE R ES HIDROGENO O ALQUILO C SUB 1-C SUB 4 Y N ES UN NUMERO ENTRE 1 Y 4, EN PRESENCIA DE UN CATALIZADOR DE ETERIFICACION ELEGIDO ENTRE HALUROS ESTANNOSOS Y CARBOXILATOS ESTANNOSOS. A process for preparing a modified epoxy resin with a molecular weight distribution of from 1.9 to 4.5 and an epoxy group content of less than 200 mmol/kg by reacting at a temperature of from 135 to 215 DEG C an aromatic epoxy resin having an epoxy group content of at least 250 mmol/kg and from 1.5 to 2.2 epoxy groups per molecule with from 5 to 170% molar excess of a dihydroxy compound of formula: in which R is hydrogen or C1-C4 alkyl and n is a number of from 1 to 4, in the presence of an etherification catalyst selected from stannous halides and stannous carboxylates.