MAGNETIC POLYMER PARTICLE, METHOD FOR PRODUCING THE SAME AND AQUEOUS DISPERSION

• Main Authors: KOBAYASHI TAKAKO, INABA YOSHIHIRO
• Format: Patent
• Language: English
• Published: 24.01.2008
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

PROBLEM TO BE SOLVED: To provide magnetic polymer particles dispersing magnetic powder in a polymer of ethylenically unsaturated monomers at high concentration and having good water dispersibility, to provide an aqueous dispersion using the particles and to provide a method for producing the magnetic polymer particles by which even a post-treatment of a polymerization reaction can easily be carried out and aggregation of the mutual particles can be inhibited to afford the desired particles in good yield even when the magnetic polymer particles are obtained by suspension polymerization in an aqueous medium. SOLUTION: The magnetic polymer particles are composed of the magnetic powder and the polymer of the ethylenically unsaturated monomers and has the content of the magnetic powder is within the range of 2.5-50 mass%. The ethylenically unsaturated monomers contain a monomer having a hydroxy group, a monomer having a carboxy group and a hydrophobic monomer free of the hydroxy group and carboxy group. In the magnetic polymer particles, the content of the hydroxy group in the polymer without containing the magnetic powder is within the range of 0.3-5.0 mmol/g and the content of the carboxy group in the polymer is within the range of 0.005-0.5 mmol/g. COPYRIGHT: (C)2008,JPO&INPIT