Phosphorylcholine group and silicone group-containing copolymer, powder coated with said copolymer and production method therefor, and use of said copolymer and said powder in cosmetics

This copolymer contains, as repeating units, (i) methacryloyloxyethyl phosphorylcholine and a derivative thereof, (ii) a silicone methacrylate, (iii) a substituted or unsubstituted straight-chain or branched alkyl methacrylate, a substituted or unsubstituted straight-chain or branched alkenyl methacrylate, or a substituted or unsubstituted cycloalkyl methacrylate, and (iv) methoxy polyethylene glycol methacrylate, and has excellent solubility in a less-polar oil. A cosmetic containing the copolymer and a cosmetic produced using a powder surface-treated with the copolymer have excellent skin affinity, moisture retention properties, water repellency, lubricative properties, and in addition, touch-proofness, which is resistance to being removed by touch. Therefore, the copolymer and the surface-treated powder are suitable for production of cosmetics.