Views: 1000 Author: Site Editor Publish Time: 2022-11-04 Origin: Site
Release agent, also known as anti-adhesive, is used between the substrate and the pressure sensitive adhesive layer. Its main function is to protect the pressure sensitive adhesive layer coated on the substrate to prevent the pressure sensitive adhesive layer from being contaminated or sticking to other items and failing.
Whether it's labels, baking paper, self-adhesive envelopes, or hygiene products, release coatings are the real hero of the entire paper industry. Many everyday applications involving pressure sensitive adhesives would not exist without release coatings.
1. Composition of organosilicon release agent
Silicone release agents generally include polymerization master agent, crosslinking agent, catalyst, solvent, inhibitor and additive, etc. Polymerization master agent is one of the main formula materials of release agent, affecting release force and release force curve, coating stability and reactivity, but also affecting curing speed, bath service life, adhesion and spread. Crosslinking agent affects adhesion, bath life and curing speed. Catalyst affects curing speed, bath life and stability. Inhibitors affect curing speed, bath life, adhesion and applicability; Additives such as heavy stripping additives can produce higher release forces, while affecting adhesion, bath life and curing speed.
2, the characteristics of silicone release agent
Characteristics of organosilicon release agent
The properties of the organosilicone release agent are mainly determined by the properties of the constituent organosilicone polymer (silicone polymer). The surface energy of organosilicon polymer is very low, the critical surface tension γc is only in the range of 19 ~ 24dyn/cm, and the release effect is good. Silicone polymers have good solventability in common aromatic and aliphatic solvents, and the viscous flow activation energy of silicone polymers is small, and the coating performance is good. It can be coated on the substrate into an extremely thin release coating. When the silicone polymer is crosslinked properly, the cohesive strength of the silicone coating and its binding force with the substrate can be enhanced, and the migration of the coating to the pressure sensitive adhesive layer can be reduced. By changing the cross-linking density of polymer and the molecular weight between the cross-linking points, the release effect of the silicone coating can be adjusted within a certain range, which makes the silicone release agent can adapt to different product requirements.