ROLE OF MATERIAL AND FORMULATING PARAMETERS IN THE ADHESION OF EMULSION PRESSURE-SENSITIVE ADHESIVES

The paper describes the effect of certain certain polymer and formulat ing parameters on the adhesion and application properties of pressure sensitive later adhesives. Increasing polar functional group content a nd molecular weight results in an increase in shear adhesion and decre ase in peel adhesion. However, the effect is not straightforward. Peel and shear obey an inverse linear relationship. A proper combination o f the type and level of polar functional group and molecular weight/di stribution leads to optimization of peel/sheer balance. Tackifiers and plasticizers increase peel and tack; tackifiers because of their uniq ue impact on rheological properties have limited adverse effect on she ar, but plasticizers greatly reduce it. Wetting agents, defoamers and theology modifiers in proper ratio improve application characteristics without a detrimental effect on adhesion. The observed effects are an alyzed in terms of the surface and bulk contributions. Practical utili ty of these results for optimizing adhesive systems is pointed out.