阳离子聚丙烯酸酯无皂乳液表面施胶剂的制备及应用

为制备一种能够明显提高纸张施胶效果和印刷性能的聚合物表面施胶剂,以聚乙烯醇(PVA)为分散剂,乙二醇单丁醚(EGME)为助溶剂,苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,通过无皂乳液共聚制备了阳离子丙烯酸酯三元共聚物表面施胶剂。确定了较佳的合成条件:种子聚合法,反应温度85℃,反应时间5·0h,w(DMC)=15%,w(PVA)=4·0%,w(KSP)=0·2%,w(EGME)=1·0%,n(BA)∶n(St)=1·2∶1·0。DSC测量出玻璃化温度为24·8℃;GPC分析出共聚物的数均相对分子质量Mn=85100,MWD=3·94;TEM显示出乳胶粒呈椭球状,其粒径约85nm。以w〔P(St-BA-DMC)〕=2·0%的聚合物乳液进行表面施胶时,可使施胶度达到9s以上,油墨吸收率为26%~27%,拉毛速率为2·9m/s,耐破度为120kPa。实验证明,所制备的三元共聚物无皂乳液表面施胶剂对提高纸张的施胶效果和印刷性能具有明显的作用。

Preparation of Cationic Emulsifier-free Emulsion of Acrylate Terpolymer and Application in Paper Surface Sizing

In order to prepare a new polymeric surface sizing agent for increasing the paper sizing and printing performance,cationic acrylate terpolymer was prepared by the emulsifier-free copolymerization of styrene (St)/ butyl acrylate (BA)/methacryloxyethyl trimethylammonium chloride (DMC),using polyvinyl alcohol (PVA) as dispersing agent,ethylene glycol mono-butyl ether (EGME) as cosolvent.According to the application results,the optimum reaction conditions were described as below:seed polymerization,temperature 85 ℃,time 5.0 h,w(DMC)=15%,w(PVA)=4.0%,w(KSP)=0.2%,w(EGME)=1.0%,n(BA)∶n(St)=1.2∶1.0.DSC and GPC characterize the glass-transition temperature (24.8 ℃) and the relative molecular weight (relative number average molecular mass 85100,molecular weight distribution 3.94) of the resulting copolymer respectively.Characterized by TEM,the morphology of emulsion particle is in the form of ellipsoid and the size is about 85nm.Treated with the diluted resulting emulsion of 2.0% solid content(mass fraction),the paper obtains good properties,that the sizing value is more than 9 seconds,the printing ink absorbency is 26%～27%,the galling speed is 2.9 m/s,and the bursting strength is 120 kPa.The cationic terpolymer shows excellent effects in the paper surface sizing and printing performance.