Styrene and alkyl methacrylate copolymer layer - having increased deformation velocity, for use in thermoplastic recording materials

摘要

Thermoplastic recording material consists of a self-supporting or deposited layer of a styrene copolymer with >=1 linear or branched 1-22 C-alkyl methacrylate. The copolymer (a) contains 1-9.9 (1.5-8.5) mol. % methacrylate and had mol. wt. distribution coefft. Mw/Mn 1.3-2.5 (1.4.2); or (b) contains 1-25(1.5-20) mol % methacrylate, has number average mol. wt. 800-2400(1500-2350) and mol. wt. distribution coefft. 1.3-2.5(1.4-2); or (c) contains 1-25 (1.5-20) mol % methacrylate, has initiator concn. 0.2-0.8 (0.5-0.7) mol/mol monomer mixt. and mol. Wt. distribution coefft. 1.3-2.5(1.4-2). Deformation rate of copolymer is increased by either (i) lowering methacrylate content in copolymer, and/or (ii) lowering mol. wt. and/or increasing initiator concn.