Studies on the Synthetic Resin Coating of Papers

Abstract

The authors have studied the effect of synthetic resin latex coating on the air resistance (AR) of paper.Two kinds of commercial latices (latex A and latex B) were used (A is the latex of PVC, Tf=75°C and B the latex of copolymer of VC and vinyliden C, Tf=15°C). Tf is the minimum film-forming temp.of latex and at this temp. one can obtain a film which have no cracks .The authors have reported the important nature of Tf for the practical use of latices (M. Fujii and Y. Otsuka, Chem. of High Polymers, Japan; 119, 93 (1955)).In this study, the commercial kraft papers were coated with the latices of various conc .and dried under various temp., some of the coated papers were cured at 120°C for 5 min .The AR was measured with Gurler densometer.The effects of latices on the AR of the papers are highly depend upon the plasticity of the resin particles, in other words, the drying or curing temp.and the important factor to determine those temp .is the Tf of the latices, if the temp. is too high or too low the low AR values are obtained.