Study And Synthesis Of Water-borne Paper-plastic Adhesive Used For Medical Materials

Nowadays the use of paper-plastic adhesive is very popular, but what we have to face isthat the performance of domestic adhesive used for paper-plastic is a little more poor thanthose imported products, especially when the adhesive is used for medical packagingmaterials, which are asked for higher performance, such as stability, peel strength, agingresistance and so on, so there is large necessity developing a environment friendlypaper-plastic adhesive with excellent performance. This paper focused on the paper-plasticadhesive developments. The research content is as following:Firstly, seed emulsion polymerization method was taken to synthesize a crosslinkingstyrene-acrylic emulsion. According to the performance effectiveness of each monomer andits characteristics contributing to the polymer product, BA and2-EHA were used as softmonomers, while St, MMA and AA were used as hard monomers. At the same time, NMAand HEMA were used as functional monomers. The content of soft monomers was68%, thecontent of hard monomers was28%and the content of functional monomers was4%. In theformula of styrene-acrylic emulsion, potassium persulfate was used as initiator, op-10anddow-fax2A-1were used as emulsifier. Cross-linked styrene-acrylic polymer emulsion weresynthesized via seed pre-emulsion method. In addition, FTIR、TEM、DSC were used tocharacterize the structure of the copolymer. The results show that all the monomers havetaken part in the polymerization reaction successfully and the shape of emulsion particles issnowman-type. The latex film has good water resistance and good temperature resistance inthe sterilization experiments while the180°peel strength is up to1.5-1.7N/1.5cm.Secondly, wax latex shows good adhesive property to the low polarity BOPP film due toits lower polarity. Suitable solid wax was emulsified in the experiments. The effect of theemulsification process of emulsifier, emulsification time, emulsion temperature, and stirringrate of the disperser were discussed. The results show that the wax emulsion with excellentstability, first-class dispersion and long stored time could be got when the HLB value of thesystem compound emulsifier is between10-18, emulsification process lasts for20minutes,emulsion temperature is85℃and the stirring rate of the disperser is1500r/min. At last, the suitable tackifier resin was selected by comparing the180°peeling strength ofdifferent tackifier resin emulsion laminating while the relationship between compositetackifier resin amount and180°peeling strength was discussed. In addition, BYK-141wasselected as defoamer through comparison of using different defoamers, CMCC was selectedas thickening agent, SiO2was selected as filler.The result shows that the best dosage of tackifierresin being20%-30%of the entire system; and this adhesive shows good stability, excellentwater resisting property, good sterilization experiment result, the180°peeling strengthachieved2.7±0.5N/1.5cm.