Shaped articles of propylene polymers having modified surface characteristics and method of making the same

Claim 1

A PROCESS FOR MODIFYING THE SURFACE CHARACTERISTICS OF SHAPED MANUFACTURED ARTICLES COMPRISING A PROPYLENE POLYMERIZATE CONSISTING PEVAILINGLY OF ISOTACTIC POLYPROPYLENE, WITHOUT ALTERING THE SHAPE OR MECHANICAL CHAROF THE STEPS OF (A) FIRST CONTACTING THE SHAPED MANUFACTURED ARTICLES WITH A GASEOUS MIXTURE CONTAINING FROM ABOUT 10% TO 100% OF OXYGEN AT A PRESSURE FROM ABOUT 1 ATMOSPHERE TO 10 ATMOSPHERES AND AT A TEMPERATURE FROM ABOUT ROOM TEMPERATURE TO 120* C. UNTIL THE OXYGEN CONTENT OF THE SHAPED ARTICLE IS FORM ABOUT 0.01 TO1.0 GRAM PER SQUARE METER, (B) THEN TREATING THE SHAPED ARTICLES WITH A LIQUID MEDIUM MAINTAINED AT A TEMPERATURE BETWEEN ABOUT 65* C. AND ABOUT 75* C. AND COMPRISING A MIXTURE OF MONOMERS COPOLYMERIZABLE WITH A RADICAL MECHANISM AND CONSISTING ESSENTIALLY OF (1) AT LEAST ONE MONOMER SELECTED FROM THE GROUP CONSISTING OF VINYL ESTERS OF CARBOXYLIC ACIDS R-COOH IN WHICH R IS AN ALKYL RADICAL CONTAINING FROM 1 TO 2 CARBON ATOMS AND CHLORINE-SUBSTITUTED DERIVATES OF SAID ACIDS, AND (2) AT LEAST ONE OTHER MONOMER COPOLYMERIZABLE WITH (1), THE AMOUNT OF (2) BEING EQUAL TO AT LEAST 5 MOLS PER EACH 100 MOLS OF (1) THAT ARE USED, WHEREBY COPOLYMERIZATION OF MONOMERS (1) AND (2) IS INITITATED BY FREE RADICALS LIBERATED BY DECOMPOSITION OF THE PEROXIDIC OXYGEN GROUPS PRESENT IN THE POLYPROPYLENE CHAIN AT THE TEMPERATURE STATED AND CHAINS OF A COPOLYMER OF MONOMERS (1) AND (2) ARE GRAFTED ONTO THE THE POLYPROPYLENE CHAINS AT THE SURFACE OF THE SHAPED MANUFACTURED ARTICLES, (C) WASHING THE ARTICLES WITH A SOLVENT FOR ANY NON-GRAFTED COPOLYMERS OF MONOMERS (1) AND (2) FORMED DURING THE TREATMENT, AND (D) DRYING THE SURFACE-MODIFIED MANUFACTURED SHAPED ARTICLES.