Silibase is one of the leading & professional manufacturers specialized in producing all kinds of SILICONE BASED new materials.
Silibase technique team always focus on quality first and insist on developing new products.
Silibase people will serve you the best before and after sale.
Apr 30, 2021
Organosilicon compounds contain the Si-0 skeleton of silicon-oxygen bonds. All or-part of the silicon atoms are combined with organic groups, such as methyl and phenyl. The surface tension of organosilicon is very small. Adhesives are difficult to adhere to. Therefore, the paper industry takes advantage of this feature and uses organosilicon compounds as release agents to produce release paper. The organosilicon compound used in the peeling paper must meet the conditions of good peeling performance, no migration to the pressure-sensitive adhesive layer, and good bond with paper. Therefore, the isolation layer must be partially cross-linked with linear polymer siloxane to form a flexible elastic film.
With my country’s opening to the outside world, in recent years, some well-known organic silicon manufacturers abroad have introduced their organic silicon products to my country. To this end, this article would like to introduce several well-known overseas silicone manufacturers to China for technical exchanges over the past two years, and introduce some types and characteristics of silicone strippers and their practical application and production.
The characteristics and scope of application of different types of strippers
Emulsion type stripper
Emulsion-type strippers can be divided into tin-catalyzed condensation polymerization and platinum-catalyzed addition polymerization. Among them, platinum catalysts have developed rapidly. The characteristics of emulsion strippers are shown in Table 2.
We have used 55g/m2 kraft paper for a coating test. As a result, the emulsion-type release agent cannot form a film on paper coated with LDPE on the surface; while coating it directly on the base paper, the film formation is good and the peeling performance is excellent. Therefore, due to the convenience in use provided by the solvent itself, and the greater physical strength of the peeling film of the solvent-based release agent, and better aging performance, the solvent-based release agent still occupies an important position in the silicone release agent. The dosage is still the largest so far. Among the two solvent-based release agents, condensation type and addition type, according to our production practice, addition type is most suitable for PE primers, while condensation type is usually used for other primers. In order to meet the needs of solvent-based coating, two kinds of base paper have been specially produced in foreign countries. Call it GLASSINE PAPER and CLAY-COATEDPAPER. Its characteristics are: low permeability, good physical strength, smooth surface, no need to coat PE or PVA, etc. 3. Solvent-free stripper
Most of solvent-free strippers are addition polymerization systems using platinum catalyst systems.Silicone emulsion composition, it comprises organopolysiloxane, organohydrogen polysiloxane, surfactant and water.By mixing two kinds of different types of organopolysiloxane, the cured silicone coating is improved with The plastic film is completely bonded and easily peeled from the pressure-sensitive adhesive. By limiting the SiH content of the organohydrogenpolysiloxane, the composition has improved storage stability. Use a specific surfactant to control the emulsion particles Size to improve the wettability of the plastic film.
Product formula of silicone release agent
The release agent with good function is generally composed of functional components and auxiliary components. Among them, the functional component can be a single organosilicon compound or polymer, but more is the use of organosilicon polymer compounding. For example, if the high and low tolerances of silicone oil are mixed, the working life of the release agent can be prolonged and the working life of the release agent can be reduced at the same time. The effect of mold release peel force. The functional components of the release agent also include crosslinking agents and catalysts that are matched with the main polymer. With appropriate catalytic strength and curing speed, the working film of the release agent is smooth and bright, and the working surface of the mold is firmly attached. Cooperate with the main organosilicon polymer to achieve the best use effect. Although the auxiliary component of the release agent plays an auxiliary role, it is indispensable. Different types of release agents are combined with different auxiliary materials. The most commonly used auxiliary components include solvents, propellants, wetting agents, preservatives, emulsifiers, and color developing agents. The solvent component in the release agent is mainly used to dissolve the main organosilicon polymer, making it a convenient operating solution for application. A good solvent requires that its polarity and solubility parameters match those of the host polymer. Some solvents also have a cleaning effect, and the release agent solution is evenly spread and adhered to the working surface of the mold. In some release agents, composite solvents are used, where the polarity and boiling point of each component are different, and the volatilization gradient is used to avoid rapid vaporization and heat absorption of a single low-boiling point solvent, so that the local dew point will cause the release agent film to whiten Defects such as wrinkles