SYNOPSISIn order to improve the weatherability of acryonitrile-styrene-butadiene rubber graft polymer (ABS resin), a n attempt was made to develop a resin (AAS resin) in which acrylic rubber of good weatherability was used instead of butadiene rubber. First, by copolymerizing dicyclopentenyl-methacrylate (DCP-MA, 3% ) with butyl acrylate, crosslinked acrylic rubber was obtained. This also introduced grafting sites into the rubber. Next, methods of graft copolymerizing styrene and acrylonitrile with this rubber were examined. An emulsionsuspension polymerization method was developed in which the initial stage of the polymerization, emulsion polymerization, changed into suspension polymerization during the process. By this method of polymerization, rubber particles were combined and enlarged, bringing about a graft-type resin with high impact resistance. This polymerization method is industrially useful because particle-shaped resins are obtained without the need of a salting-out process. The AAS resin, obtained in this way, has much improved weatherability over ABS resin and shows strength equal to that of ABS resin.

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We studied on the change of flow properties of P.V.C. affected by adding different agents, using a flow tester. With the increase in the amounts of the added isophorone, the connected structure, which is the aggregate of molecules of molten P. V. C. decreased owing to the solvation of isophorone to P. V. C. and the fluidity of P.V.C. increased. The apparent activation energy of the flow was obtained from the relation between volume of flow and temperature.It was found that the value has decreased in proportion to the amounts of added isophorone. In room temperature, isophorone has much better solvation power against P. V. C. than usual plasticisers, but at higher temperature it shows a poorer affinity as usual plasticisers where thermal motions of P. V. C. are vigorous. (6) ON THE MELT SPINNING ABILITY OF POLYVINYLCHLORIDE 1. The effects of both pressure and temperature on the flow property of P. V. C. (Geon 103)into which isophorone was added were investigated.From this investigation, the Ostwald's equation log Q=log Kp n was found to be applicable, where Q is the volume of flow per minute, p the extruding pressure, and K and n constants.2. We calculated the value of the constant n, and the temperature at which n corresponds to unity was found to be 215°C for the plasticised P. V. C. and 250°C for the unplasticised P. V. C.from the relation between n and the reciprocal absolute temperature.As the spinning ability was very good at the point where n was slightly over unity, pure P.V. C. with no plasticiser was found to be usable for melt spinning at the near temperature. (Received 21. 12. 1956)

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