Date of Award
Bachelor of Science
Paper Science and Engineering
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.
Bartholomew, Kent, "Prediction of Release Properties of Silicone Coated Paper Through Analysis of Coating Particle Size and Distribution" (1989). Paper Engineering Senior Theses. 22.