Date of Award

12-1989

Degree Name

Bachelor of Science

Department

Paper Science and Engineering

Abstract

Silicone release coatings are gaining in popularity. The use of water-borne emulsions is seeing its way into the production of release coatings as well as pressure sensitive applications.

Thermoset silicone release coatings systems consist of a reactive polymer, a crosslinker, and a catalyst. A condensation reaction takes place to form the low surface energy silicone film which is primarily what gives good release property.

It is believed that an emulsion's stability, and hence quality, can be related to the particle size and distribution.

It was the goal of this study to quantify the relationship between particle size/distribution and release properties of a silicone treated base sheet as the emulsion stability deteriorated. Some parameters that affect an emulsion's stability are temperature, pH, shear, and hardness of the water. The study was conducted by applying high shear over time keeping all the other parameters constant.

Over time, flocculation and coalescence of the particles indicated the emulsion stability to be deteriorating. This was evident by an increase in Kiel release values, percent flocs, average area of particles, and a decrease in coat weight and sub-adhesion.

These results confirmed the hypothesis that a correlation exists between particle size/distribution and that this can be used to predict release properties of silicone coated paper.

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