Method for producing cationic surface sizing agent, and sizing agent obtained by method

• Main Authors: SODEYAMA TAKUJI, INAOKA KAZUSHIGE, HAYASHI YOKO
• Format: Patent
• Language: Chinese; English
• Published: 18.12.2013
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; IMPREGNATING OR COATING OF PAPER; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PAPER NOT OTHERWISE PROVIDED FOR; PAPER-MAKING; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; PRODUCTION OF CELLULOSE; PULP COMPOSITIONS; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TEXTILES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G

The present invention relates to a method for producing a cationic surface sizing agent. The method contains a first step for obtaining a copolymer (A) by solution-polymerizing of a monomer mixture that contains specific proportions of a monomer (a) containing a tertiary amino group, a specific (meth) acrylic acid ester (b), and a styrene (c), while in the presence of a chain-transfer agent; a second step for obtaining a copolymer (B) by polymerizing the copolymer (A) and a hydrophobic monomer (d) in a manner such that the copolymer (A) constitutes a specific proportion, while in the presence of a surfactant, and in an oxidation-reduction system that contains a water-soluble, free-radical initiator and a heavy metal salt; and a third step for obtaining quaternary ammonium salt of the copolymer (B) by quaternizing a tertiary amino group in the copolymer (B).