High-performance Waterborne Acrylic Pressure-sensitive Adhesive

Water is solvent in acrylate emulsion, it is no environmental pollution and low cost,therefore, it has been used widely in coatings, printing ink, adhesives, rubber industry and soon. However, in some areas, its application is restricted for its poor peel strength and hightemperature resistant. In order to enlarge its application, it needs to be modified.Acrylate emulsion with high performance was prepared through seeded emulsionpolymerization using butyl acrylate（BA）,2-ethylhexyl acrylate（2-EHA）, methylacrylate（MMA） as the main materials, acrylic acid and hydroxyl ethyl methacrylate asfunctional monomers, sodium dodecyl sulfate（SDS） and nonylphenol ethoxylate （OP-10）asemulsifiers, N-methylol acrylic amide as the internal cross-linking agent. Then curing agentwas added into Acrylate emulsion, a kind of two component pressure sensitive adhesive （PSA）was made. Effects of reaction temperature, reaction time, emulsifier, initiator, monomers andcuring agent on the properties of emulsion, film and PSA were investigated.The experimental results showed that when reaction temperature was80℃, reactiontime was6h, emulsifier SDS and OP-10content was4%, the initiator content was0.6%, theratio of MMA/2-EHA/AA was80/10/4, acrylic hydroxyl ethyl content was4%, crosslinkagent content was2%, curing agent content was0.6%, the appearance of emulsion was blue,its particle size was145μm, and its stability is better. At the same time, the performance ofthe pressure sensitive adhesive was excellent, its180°peel strength was238N m^-1, initialtack was No.30steel ball, holding power was above300h, and the Heat-resistant holdingpower at100°C was above8h.In order to improve the adhesive strength and decrease its viscosity, Tackifier resin（TR）was added in the experiment.The experimental results showed that when reaction temperaturewas80℃, reaction time was6h, emulsifier SDS and OP-10content was4%, the initiatorcontent was0.6%, the ratio of MMA:2-EHA: AA was80:10:4, acrylic hydroxyl ethylcontent was4%, crosslink agent content was2%, curing agent content was0.6%, theappearance of emulsion was blue, its particle size was125μm, and its stability is better. Atthe same time, the performance of the pressure sensitive adhesive was excellent, its180°peelstrength was288.2N m^-1, initial tack was No.31steel ball, holding power was above300h,and the Heat-resistant holding power at100°C was above8h.Tackifier resin（TR）-acrylates complex latexs were prepared by seed shell-emulsionpolymerization. Their properties were characterized by infrared spectrometry （FTIR），Differential Scanning Calorimetry （DSC）, Zeta potential, Particle Size Analyzer, Atomic Force Microscope （AFM）etc. At the same time the PSA properties were tested by universaltensile machine, initial tack device and the holding power device. FTIR showed that tackifierresin and acrylic ester had copolymerizated; DSC showed that emulsionhad one glasstransition temperature Tg, both of them proved that tackifier resinand acrylic ester hascopolymerizated; Zeta potential showed when ξ potential was blow-30mv, latex was stable.When ξ potential was above-30mv, gravitational potential energy of latex was aboverepulsion potential energy, particles would gel for their attracting each other. AFM showedthat the emulsion particle size decreased, stablity increased, the film surface morphologyeven, more excellent performance of the latex. With the increasing of tackifying resin, tack andpeel strength of PSA were improved. With the increasing of curing agent content, the holdingpower increased. The properties of PSA were excellent and it will meet the needs of specialareas.