高速卷烟胶用VAE乳液渗透性能研究

Study on permeability of VAE emulsion for high speed cigarette adhesive

从乳液聚合反应机理出发,通过探索新的混合氧化还原引发体系及优化工艺条件,探讨了改进乳液渗透性能的方法。研究结果表明:影响乳液渗透性能的主要因素是引发剂品种和聚合反应工艺。通过探索合适的引发体系,选择混合氧化剂A1/A2—还原剂B3的引发剂搭配,并且还原剂采用连续滴加的工艺,可以达到提高乳液渗透性能的目的。A2在混合氧化剂中的所占比例越高,渗透性越差,但反应速度越快。A2较佳比例在25%~40%之间,兼顾了渗透性和较高的反应速度。在82~86℃、6.0 MPa反应压力、保护胶体用量为单体的5%~7%、保护胶体中羟乙基纤维素(HEC)配比控制在15%,可获得目标黏度1 000~2 500 m Pa·s的乳液产品,乙烯含量为(16±2)%。该VAE乳液渗透性、流变性好,初粘速度快,达到烟厂高速烟机上机要求。

Starting from the reaction mechanism of emulsion polymerization,the method of improving emulsion permeability was discussed by exploring new mixed redox initiating system and optimizing technological conditions.The research results showed that the main factors affecting the permeability of emulsion were initiator and polymerization process.By exploring suitable initiating system,the collocation of initiator of mixed oxidants A1/A2-reducing agent B3 and the continuous dropping process of reducing agent were used to improve the emulsion permeability.The higher the proportion of A2 was in the mixed oxidants,the worse the permeability was,but the faster the reaction rate was.The optimal ratio of A2 was 25%-40%,which took into account the permeability and high reaction rate.The emulsion product with target viscosity of 1 000-2 500 mPa·s could be obtained at 82-86 ℃,6 MPa reaction pressure,and dosage of protective colloid was 5%-7% of monomer,HEC ratio of protective colloid(HEC)was controlled at 15%,and ethylene content was(16±2)%.The VAE emulsion had good permeability and rheology,and its initial adhesive speed was fast,which ruet the requirements of high speed cigarette adhesive.