| Acrylic pressure sensitive adhesive has excellent pressure sensitivity,adhesive and weather resistance,and can be used in packaging,medical,labeling and other fields.Since 2015,the state has issued a series of policies such as"Action Plan for the Reduction of Volatile Organic Compounds in Key Industries"and"Technical Requirements for Low Volatile Organic Compound Content Coating Products"to encourage the production of waterborne coating products,so the market prospect of waterborne acrylic pressure-sensitive adhesives is very broad.Emulsion acrylic pressure sensitive adhesive have the advantages of safe and environmental protection,simple production operations,and not easy to leave residual adhesive,which can be well applied to PET tape.However,acrylic pressure sensitive adhesive currently applied to PET tape often has problems such as insufficient adhesion performance,imbalance between adhesion and peel strength.In addition,due to insufficient solvent resistance,its application scope is limited.In view of the above shortcomings,this paper uses seed emulsion polymerization method to prepare emulsion-type solvent-resistant epoxy-acrylic pressure-sensitive adhesive,which has excellent adhesion performance,cohesive strength and solvent resistance,and can be applied to PET tape.The main content is as follows:（1）Taking acrylic raw materials as a clustering monomer to prepare emulsion acrylic pressure sensitive adhesive.After determining the time,temperature and stirring speed of the polymerization reaction,the effects of the types of hard monomers on the properties of pressure sensitive adhesives was investigated.In a system without adding hard monomers and a system with styrene,add cross-linking agents,the effects of the type,molecular weight,and addition amount of cross-linking agents on the performance of pressure sensitive adhesives were investigated.It was finally discovered that the solution parameters of the hard monomer have a greater impact on solvent resistance.In addition,although the addition of the cross-linking agent can increase the internal agglomeration of the polymer to a certain extent and enhance the adhesion and solvent resistance,it has a negative impact on the peeling force.Experiments show that the pure acrylic system is difficult to take into account bonding performance,internal agglomeration,and solvent resistance.（2）Taking epoxy resin as hard monomers,the remaining ingredients of acrylics are soft monomers and functional monomers,and epoxy-acrylic pressure sensitive adhesives is prepared.Use infrared spectrum,viscosity meters,Zeta potentiometer,etc.to characterize the emulsion,and explore the impact of various factors such as the contouring agent content,functional monomer content,hard monomer content,buffer content and other factors on emulsion state and pressure sensitive adhesive performance.Experiments show that the epoxy resin E-20 content is 2.5%,the seed emulsion content is 5%,the functional single content is 10%,the contouring agent content is 0.5%,the2-EHA accounts for 35%of the soft item,the buffer content is 0.5%,not added molecular weight regulator is the best comprehensive performance.（3）Modified epoxy acrylic pressure sensitive adhesive with silicone containing double bonds to prepare better performance silicone modified epoxy acrylic pressure sensitive adhesive.Use infrared spectrum,viscosity meters,and particle size meters,etc.to characterize the emulsion,and explore the effects of organic silicon species and content on the state of emulsion,particle size,viscosity,and pressure sensitive adhesive performance.The experiment showed that when 1%of A-151 was added,the performance of the pressure sensitive adhesive was improved,The peeling force was increased from 14.97 N·（25 mm）-1to 15.79 N·（25 mm）-1,the tack was increased from 8#to 10#ball,the holding force was greater than 48 hours,and the solvent resistance grade was increased from 4 to 5.At the same time,the emulsion is white pan-blue light,the gel rate is low,which can meet the application standards.It can be applied to PET tape wiped by toluene solvents. |
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