Molding resin composition

#This invention relates to a resin composition suitable for vacuum forming and capable of giving soft or semi-rigid leather-like sheets. More particularly, this invention relates to a resin composition moldable by vacuum forming and capable of giving soft or semi-rigid leather-like sheets, which comprises [A] a vinyl chloride resin, [B] an alkenyl aromatic compound-butadiene rubber-alkenyl cyanide compound-methacrylate resin, [C] an acrylonitrile-butadiene rubber and [D] a plasticizer for vinyl chloride resins.

#For the production of sheets for vehicles such as automobiles, and the like, there have hitherto been proposed various processes such as production of a molded product from the above-mentioned type of resin composition by the vacuum forming technique followed by insertion of a lining cushion into its inside or followed by injecting a polyurethane or the like into the inside of the molded product and foaming the same into a sponge.

#These sheets must have the following performances:

#Sheets were prepared by varying the composition, the degree of grafting and the [.eta.] of the graft copolymer [B] as shown in the Table. The compounding recipe of the sheet, the forming method and the testing method were as mentioned above.

#The graft copolymer [B] used in Example 2 was produced in the following manner: 10 parts by weight of potassium salt of disproportionated rosin (concentration 25% by weight), 200 parts by weight of water and 30 parts by weight (in terms of solids) of a styrene-butadiene rubber latex were placed in a polymerization reactor and stirred under a nitrogen stream, after which 3.5 parts by weight of styrene, 5.2 parts by weight of acrylonitrile, 5.3 parts by weight of methyl methacrylate, and 0.1 part by weight of t-dodecyl-mercaptan were added under a nitrogen stream in the same manner as above. When the inner temperature reached 40.degree. C., 0.14 part by weight of cumene hydroperoxide and a solution of 0.003 part by weight of FeSO.sub.4.7H.sub.2 O, 0.045 part by weight of ethylenediaminetetraacetic acid tetrasodium salt, 0.03 part by weight of sodium formaldehydesulfoxylate, 0.4 part by weight of sodium pyrophosphate and 0.5 part by weight of anhydrous crystalline glucose in 10 parts by weight of water were simultaneously added with continuous stirring to start the polymerization. One hour after the start of the polymerization, the inner temperature was 53.degree. C. At this time, it was started to continuously add a mixture consisting of 14.0 parts by weight of styrene, 21.0 parts by weight of acrylonitrile, 21.0 parts by weight of methyl methacrylate and 0.4 part by weight of t-dodecylmercaptan together with 0.21 part by weight of cumene hydroperoxide over a period of 3 hours, whereby the polymerization was completed. At the end of the polymerization, the inner temperature was 75.degree. C., and the conversion of the monomer to the polymer was 99%. The latex was coagulated with sulfuric acid, washed with water, filtered and dried to obtain a polymer.

#In other Examples and Comparative Examples, the graft copolymer [B] was produced by substantially the same procedure as above, except that the amount of rubber and the proportions of monomers were varied.