Mitsui Toatsu Chemicals, Incorporated

Yasuo Furuta

Norifumi Ito

Mune Iwamoto

Tetsuyuki Matsubara

Toshihiko Ando

Kazuo Sugazaki

Yuzuru Ishida

Hitoshi Ozawa

Kouzo Ichikawa

A process for preparing rubber modified high impact resins by dissolving a rubbery polymer in a monomer containing an aromatic vinyl monomer or a mixture of an aromatic vinyl monomer and a vinyl cyanide monomer followed by polymerizing the monomer, the two steps being carried out in at least two polymerization reactors with a particle disperser placed between the first and second reactors. High impact resins having excellent surface properties are obtained with a savings in a power consumption by controlling:

Continuous process for preparing rubber modified high impact resin

Disclosed herein is a rubber-modified styrene copolymer which contains as an impact strength modifier a rubbery polymer having a viscosity of 2-250 centipoises as measured at 25.degree. C. as a 5 wt. % styrene solution and a styrene insoluble content lower than 0.1 wt. %, produced by anionic polymerization and dispersed in a continuous phase of a styrene-acrylonitrile copolymer. The rubbery polymer contains small particles of the same styrene-acrylonitrile copolymer occluded in the form of cells. The areas of particles in each of which the maximum cell diameter is smaller than 0.1 .mu.m are at least 40% of the area of all the particles of the rubbery polymer and the volume average particle size of these particles is 0.1-0.4 .mu.m. The weight ratio of the monomers in the styrene-acrylonitrile copolymer is 90/10.gtoreq.styrene/acrylonitrile.gtoreq.55/45. Per 100 parts by weight of the copolymer, the proportions of polymers having a molecular weight greater than 1,000,000 is smaller than 0.5 part by weight while the proportion of polymers having a molecular weight greater than 1,200,000 is smaller than 0.01 part by weight.

Anionically-polymerized-rubber-modified styrene copolymers

Disclosed is a process for continuously producing rubber modified styrene resins wherein the rubbery phase including a rubber-like polymer is transformed into dispersed particles by using a reactor having both a helical-blade agitator mounted in a draft tube and an auxiliary agitator, by establishing a specified agitating force and a specified degree of circulation of the fluid within the reactor, and by maintaining a specified relation between the weight percentages, based on the total amount of all components within the reactor, of the rubber-like polymer and the monomer converted to polymer. According to this process, various grades of high-impact rubber modified styrene resins having excellent surface properties can be obtained without any adhesion of rubber-like matter to the reactor and without any formation of fisheyes in final products.

Process for producing rubber modified styrene resins

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Hiratsuka, Japan

Yasuo Furuta