| 摘要 |
A multi-layer structure polymer composition having a gel content of at least 50% which is constituted of an innermost layer polymer (A) consisting mainly of alkyl acrylate and having a degree of swelling of 10 or lower, and having a glass transition temperature lower than 10 DEG C., a crosslinked elastomer polymer (B) consisting mainly of alkyl acrylate and having a degree of swelling slightly higher than that of said polymer (A) and having a glass transition temperature not higher than 0 DEG C., said innermost layer polymer (A) and said crosslinked elastomer polymer (B) constituting a double layer elastomer structure polymer, as well as an outermost layer polymer (C) consisting mainly of alkyl methacrylate and having a glass transition temperature not lower than 60 DEG C., and at least one intermediate layer (D) existing between said polymer (B) layer and said polymer (C) layer, the amount of alkyl acrylate in said intermediate layer (D) linearly decreasing from said polymer (B) layer to said polymer (C) layer. Said polymer composition does not readily show the phenomenon of whitening even if dipped in hot water or boiling water and is excellent in weather resistance, solvent resistance, stress-whitening resistance, water-whitening resistance and transparency. |
