Preparation And Research Of Waterborne Acrylate Pressure-sensitive Adhesive On Label

Waterborne acrylate pressure-sensitive adhesive(PSA) have been widely used on label due to its advantages of environmental protection and safety, simple operation. Hower, the development and application of waterborn acrylate PSA was limited in domestic market because of the main existing problems such as poor adhesive properties, easy migration of emulsifier, imbalance between adhesion and cohesion, poor aging resistance. To overcome these problems, a kind of acrylic emulsion was prepared with reactive emulsifier in this paper. And based on this, the small molecular weight acrylic emulsion and epoxy resin modified acrylic water dispersion were blended with original acrylic emulsion to obtain a modified waterborne acrylate PSA.In the experiment, compound reactive emulsifier DNS-86/ ANPEO10 was selected to the the seed emulsion polymerization and the effects of various factors on the mechanical properties of acrylic emulsion and PSA were investigated. Moreover, other properties of acrylic emulsion were characterized by particle size analyzer, infrared spectrometer(FTIR), differential scanning calorimeter(DSC). The result showed that, reactive emulsifier was successfully polymerized to acrylate which can effectively solve the problem of migration, and the adhesive property has been greatly improved. When the seed emulsion content between 6wt%~10wt%, initiator APS content was 0.5wt%, chain transfer agent was 0.08wt%, the theory of the glass transition temperature was-44.3℃, m(EHA): m(BA) =30:50, reactive emulsifier content was 0.8%wt, DNS-86/ ANPEO10=2:1, CEA and HEA were 3wt% and 4wt%, the polymerization process was stable and high conversion rate, the mechanical properties of PSA products were the best. Based on this, the amount of 20wt% of low molecular weight acrylic emulsion with 0.28wt% chain transfer agent and-30.2℃glass transition temperature was added to obtain the blending acrylic emulsion which was proved that the molecular weight distribution was increased and the 180° peel strength was greatly improved while tack shears trength were in good performance.In order to have further improvement of the bonding and aging resistance of the PSA, the water dispersion of epoxy resin modified acrylate was blended with acrylic emulsion. The results showed that when the content of E-44 was about 7wt%, acrylic acid was 6wt% and the degree of neutralization control in the range of 100%-110%, the stability of water dispersion is good and the solid content is high. When the amount of water dispersion of epoxy resin modified acrylate that blended with acrylic emulsion was 15wt%-25wt%, the three mechanical properties are more balanced. And the 180° peel strength can reach above 8N·25mm-1. After several testing such as FIRT, DSC, CPC and TGA, epoxy resin was proved to be grafted on acrylate with good good compatibility. The molecular weight distribution of acrylic emulsion that was blended with water dispersion was more broadened, and the thermal stability and aging resistance were better.