Receptive paper for pressure sensitive copying system - contains hydrophi-lic trioctahedral smectite (saponite or hectorite) clay in receptive coating

摘要

Title clay can be used instead of attapulgite, which is expensive, and can give at least as good results. The clay should have an exchangeable cation capacity (molar basis) of is not 60% Na + Li + and pref. 40% Mg2+, Ca2+, Zn2+, Ni2+, Cu2+, Ba2+, Cd2+ and/or Hg2+. The clay is saponite, esp. in acid-treated form, with a surface area 80m2g-1. The coating contains 3-8g m-2 and also contains a starch binder. Natural and synthetic hectorites are also suitable.