Polyorganosiloxane latex, graft copolymer using the same, thermoplastic resin composition, and molded body
View Patent ↗A variety of molded bodies having high weatherability, impact resistance, designability, and the like, and a polyorganosiloxane latex and a graft copolymer used as the raw materials therefor are provided, where the polyorganosiloxane latex has a mass average particle diameter (Dw) of a polyorganosiloxane particle of 100 to 200 nm, and a ratio of the mass average particle diameter (Dw) to a number average particle diameter (Dn) (Dw/Dn) of 1.0 to 1.7. A polyorganosiloxane-containing vinyl-based copolymer (g) obtained by polymerizing one or more vinyl-based monomers in the presence of the latex. A graft copolymer (G) is obtained by graft polymerizing one or more vinyl-based monomers in the presence of the copolymer. A thermoplastic resin composition includes the graft copolymer (G) and a thermoplastic resin (Ha) except for the graft copolymer (G). A molded body is obtained by molding the resin composition.
1. A method of preparing a polyorganosiloxane latex, where a polyorganosiloxane particle of the latex has a mass average particle diameter (Dw) of 100 to 200 nm, and where a ratio (Dw/Dn) of the mass average particle diameter (Dw) to a number average particle diameter (Dn) is 1.0 to 1.7, the method comprising:
dropping an emulsion (B) comprising an organosiloxane, an emulsifier, and water into a water-based medium (A) comprising water, an organic acid catalyst, and an inorganic acid catalyst; and
polymerizing the organosiloxane,
wherein:
a total amount of the organic acid catalyst and the emulsifier is 0.5 to 6 parts by mass based on 100 parts by mass of the organosiloxane,
the water-based medium (A) is at a pH within the range of 0 to 1.2 when measured at 25° C., and
the dropping of the emulsion (B) is at a rate such that an amount of the organosiloxane fed is 0.5 parts by mass/min or less when a total amount of the organosiloxane to be used is 100 parts by mass.
2. The method according to claim 1 , wherein a standard deviation of the mass average particle diameter (Dw) of the polyorganosiloxane particle is 0 to 80.
3. The method according to claim 1 , wherein a proportion of the polyorganosiloxane particles having a particle diameter of less than 50 nm is 5% by mass or less based on the total amount of the particles, and wherein a proportion of the polyorganosiloxane particles having a particle diameter of 300 nm or more is 20% by mass or less based on the total amount of the particles.
4. The method according to claim 1 , wherein the polyorganosiloxane particle has a mass average particle diameter (Dw) of 100 to 190 nm.
5. A method of preparing a polyorganosiloxane-containing vinyl-based copolymer comprising:
preparing by the method according to claim 1 the polyorganosiloxane latex, and
polymerizing one or more vinyl-based monomers in the presence of the polyorganosiloxane latex.
6. The method of claim 5 , where a particle of the polyorganosiloxane-containing vinyl-based copolymer has a mass average particle diameter (Dw) of 110 nm to 800 nm, and a ratio (Dw/Dn) of the mass average particle diameter (Dw) to a number average particle diameter (Dn) is 1.0 to 2.0.
7. The method of claim 5 , wherein the vinyl-based monomer is an acrylic acid ester.