Study On Preparation,application & Acting Mechanism Of Neutral Rosin Sizes

The rosin sizes are still the mainl~ sizing agents for paperrnaking by now. The cationic rosin sizing agents are called to be the fourth generation production from the soaped sizes. the fortified sizes and the anionic rosin sizes of emulsion. Simultaneously. the papermaking technology have been conversing from acidic to weekly acidic or neutral sizing. Also the non-wood fiber are still the mainly materials for papermaking in china, but using the eucalyptus wood as the new raw material for papemiaking at neutral conditions will be the direction of development. The present investigation relates to sizes for a papermaking. more specifically to an internal size which works very well in papermaking under weakly acidic to neutral conditions. Series emulsions of rosin sizes have been gotten based on lots of the literatures of at home and abroad. (1) The XQ-CR cationic rosin sizes and the XQ-AR anionic rosin sizes have been developed. Conventional rosin emulsion sizes consists mainly of so-called fortified rosins, i.e., rosins modified with ctj~-unsaturated dibasic acids, and an anionic surfactant. Among a few of anionic surfactants. the sulfate ester of the maleic anhydride and polyoxyethylene nonylphenyl ether has shown to be the effective emulsifying agent. The anionic and cationic rosin sizes are both used in a dispersion in the present of the alkyl acrylate resin emulsions which can be used as the size synergist. (2) Comprising a rosin sizing agent fortified by adding the same ionic copolymer emulsion of alkyl actylate with stvrene wherein the rosin and modified rosin are dispersed in water with the aid of an emulsifying agent and the size synergist, and paper sized therewith. The rosin emulsion sizing agent of the present invention have exhibited an distinguished sizing effect in neutral papermaking systems even when content of the calcium carbonate is high therein and been excellent in mechanical and storage stability while decreasing the production cost in addition the sizing agent presents no significant difficulties in its production. (3) To increase the size degree of above rosin emulsion, the polyaminoamide epichlorohydrin (PAE) has been used. Comprising the copolymer of cationic acrylamide with other hydrophilic monomer and the cationic starch, it serves very well as both a retention aid and a sizing agent for neutral paper because its sizing quality around theneuthel pH is low The high molecular weight ard the Stronger cationic ctwes arenecesSary for attributing the excellent proPerties of retention and sizing. Not only as thesPecial retention agent for rosin sizes, but also the PAE can be used as the wetreinfOrcing agent by crossing of itself at the neutrai or basic condition.(4) The best conditions of preparaion and aPpiicaion of above products have beendetendned, the sizing technology of catiohic size XQ-CR is as mis: sulfate altalniurn4%. XQ-CR 0.5W1 .0%,PAE 0.259M.5%. calciurn carbomate 25% with the reversesining. in the summer, the disadvantaged infiuences of high temperatUr and high pHvalue tO sdrig are reduced by adding more sulfate aIurnndum and sizing agent and PAE.The selected technology ofedonic sizing agen XQ-AR is as this: XQ-AR 0.5Wl.0%.sulfate aiwtum 4%, PAE 0.259ed.5%. talcium carbomate 25% with the betseq.(5) The measure ofsimCtUr and Properties for above ProduCts are cAned out. lt ishelpful for studying on the chdrical interachon mechasm betwen aids and the Paperfiber and neutral sthe mecbosm in wet processing.