キャビテーション噴流を用いた微粒子炭酸カルシウムとパルプの複合体の開発

Abstract

Studies on the synthesis and characterization of a hybrid fi ber (HF) consisting of precipitated calcium carbonate (PCC) and cellulose fi ber were conducted. The PCC-HF has been prepared by modifying the carbon dioxide (CO 2) method for PCC synthesis under high-pressure fl uid-jet cavitation in hardwood bleached kraft pulp (HBKP) slurry. Scanning electron microscopy (SEM) observations of the HF showed that almost all fi ber surfaces were covered with nano-size PCC particles. By using this PCC-HF as raw materials, the handsheet containing more than 50％ PCC by weight with a high first-pass ash retention (greater than 80％). Unlike ordinary paper such as printing paper, the sheet showed remarkable physical properties, such as high fl exibility without crumbling despite extreme high ash content. The SEM images from a cross section of the sheet containing 74％ PCC revealed that a very little number of fi bers embedded in PCC layer. This implied that the bonding mechanism of HF sheet was diff erent from ordinary paper. In order to clarify the mechanism, the slurry of PCC-HF for handsheet making was separated into two fractions, long fi bers and fi nes, by using the Dynamic Drainage Analyzer (DDA). It was found that the nano-size PCC was attached onto not only the surfaces of the long fi bers but also those of fi ber fi nes. Thus, the PCC-hybrid fi ber fi nes contributed sheet properties and high ash retention. Keywords： cavitation, composite, high fi ller, calcium carbonate, fi ller retention 分類：L 0 その他，S 0 その他