Patent ID: 6348542
Filing Date: 2002-02-19
Classification: C08F

Abstract:
(1) Multiphase structured polymer particles comprising at least three phases comprising at least two of the following inner rubber component phases (I), and at least one of the following thermoplastic resin component phases (II) in at least the outermost part, wherein:(2) the rubber component phases (I) are polymer phases formed by copolymerization of a monomer mixture (i) comprising 50-99.99 wt % of an acrylic acid ester, and 49.99-0 wt % of another monofunctional monomer together with 0.01-10 wt % of a polyfunctional monomer capable of copolymerization with the acrylic acid ester, at least two of the rubber component phases (I) being mutually adjacent to each other and having mutually different monomer unit compositions, (3) the thermoplastic resin component phase (II) is formed by copolymerization of a monomer mixture (ii) comprising 40-99 wt % of a methacrylic acid ester, and 60-1 wt % of another monomer capable of copolymerization with the methacrylic acid ester, (4) the polymer which constitutes the phase situated in the outermost part among the thermoplastic resin component phases (II) has a number average molecular weight of 30,000 or less measured by the GPC method, (5) the ratio of the total weight of the rubber component phases (I) and the total weight of the thermoplastic resin component phase (II) is in the range of 30/70-80/20 expressed as phase (I)/phase (II), (6) the average particle diameter is 150 nm or less, (7) for all of those phases constituting the rubber component phases (I) which ate mutually adjacent to each other, the absolute value of the difference of the solubility An in water of the monomer mixture forming the nth phase from the innermost part, and the solubility An+1 in water of the monomer mixture forming the n+1th phase adjacent to it, is 0.36 or less (where An is the sum of the products of the weight fraction of each monomer in the monomer mixture forming the nth phase and the solubility of the monomer in water at 20Â° C. (g/100 g H2O), and An+1 is the sum of the products of the weight fraction of each monomer in the monomer mixture forming the n+1th phase and the solubility of the monomer in water at 20Â° C. (g/100 g H2O), and (8) the absolute value of the difference of the refractive index nd(I) of any of the phases in the rubber component phases (I), and the refractive index nd(II) of any of the phases in the thermoplastic resin component phase (II), is less than 0.005 for all phase combinations.