C - Chemistry – Metallurgy – 08 – F
Patent
C - Chemistry, Metallurgy
08
F
400/1132, 400/20
C08F 253/00 (2006.01) C08F 279/02 (2006.01)
Patent
CA 1114984
ABSTRACT OF THE DISCLOSURE The invention is concerned with a process for the manufacture of a styrene polymer modified with rubber to improve its impact strength, by polymerizing styrene in the presence of 1 to 20% by weight, based on styrene, of rubber in at least two stages, wherein, in a first stage, the styrene, which contains the rubber in solution, is prepolymerized at from 50 to 150°C in the presence or absence of inert diluents, while breaking up the disperse soft-component phase which forms during the polymerization by shearing the polymerization mixture until the quantity of styrene converted, based on the starting solution to be polymerized, corresponds to from 3 to 10 times the amount of elastomer constituent of the total amount of rubber employed and the particles of the disperse soft component phase thus formed have a mean diameter of less than 6 µm, and thereafter, in one or more further stages, the polymerization is completed by taking it to the desired conversion with reduced shearing or entirely without shearing, in mass, in solution or in aqueous suspension. The process of the invention is characterized in that the shearing during prepolymerization is carried out in such a way that the particles have a weight-average mean diameter of less than 1 µm and a narrow particle-size distribution, and the disperse soft-component phase contains, during the prepolymeriza- tion, from 35 to 65% by weight of free or chemically bonded polystyrene segments being incorporated into the rubber component in a chemically bonded form as a polymer block or a grafted branch, the segments having a number-average molecular weight of at least 30,000. The styrene polymers obtained exhibit not only high impact strength but also improved transparency, and may be used for packaging purposes.
273939
Echte Adolf
Fahrbach Gerhard
Jung Rudolf
Stein Dieter
Walter Manfred
Basf Aktiengesellschaft
Robic Robic & Associes/associates
LandOfFree
Manufacture of styrene polymers which have been modified to... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Manufacture of styrene polymers which have been modified to..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Manufacture of styrene polymers which have been modified to... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-671093