Mechanism of Water- and Oil-Repellency Behavior of Paper Prepared by Internal Addition of Fluorine-Containing Reagent

Abstract

Handsheets were prepared from pulp slurries by internal addition of a water-soluble fluorochemical (fluoroalkylphosphate diethanolamine salt) with or without polyamideamine-epichlorohydrin resin (PAE), and water- and oil-repellency behavior of the handsheets was studied in terms of handsheet-making conditions. The micro-flask combustion method and X-ray fluorescence analysis were used to determine fluorochemical contents in the handsheets. The fluorochemicals were retained in the handsheets by electrostatic interactions through PAE, in which case high degrees of water- and oil-repellency were given to the handsheets. Nearly no fluorochemicals were retained in the handsheets without PAE. In most cases, water-repellency of the handsheets was sensitively influenced by the handsheet-making conditions, whereas oil-repellency was roughly governed by the fluorochemical contents in the handsheets. The key factors for improvement of water- and oil-repellency may lie not only in retaining the fluorochemicals but also in controlling distribution or agglomeration of the fluorochemicals in the handsheets.