Silicone products have good electrical insulation performance, its dielectric loss, voltage resistance, arc resistance, corona resistance, volume resistivity and surface resistivity are among the best insulating materials, and their electrical performance is very little affected by temperature and frequency.Therefore, they are a stable electrical insulation material, which is widely used in electronic and electrical industries.In addition to excellent heat resistance, silicone also has excellent water repellency, which is the guarantee of high reliability for the use of electrical equipment under wet conditions.

    Excellent performance of silicone:

    (1) chemical inert, will not react with other foaming substances;

   （2）Physiological inert, non-toxic, pollution-free, harmless to the environment;

    

    (3) It has excellent softness and lubrication performance, which is conducive to improving the quality of coated paper.However, the price of defoaming agent silicone products is relatively high, so that some manufacturers can not accept, leading to the current silicone defoaming agent has not been widely used.In fact, from the perspective of dosage, because of the small amount of silicone, usually only need to add the mass fraction of the system 1 ~ 75×10-6 can achieve good defoaming effect, if combined with other defoaming agent can further reduce the cost.Taking all things into consideration, the cost of using silicone as defoaming agent will not increase compared with other defoaming agents.With the continuous improvement of silicone synthesis technology and the continuous reduction of raw materials, the problem of high price of silicone can certainly be solved, so containing silicone defoaming agent will be the hot spot of papermaking defoaming agent market.

    To use:

    1, can be widely used in erythromycin, lincomycin, avermectin, gentamicin, penicillin, oxytetracycline, tetracycline, tylosinin, glutamic acid, lysine, citric acid, xanthan gum and other fermentation industry.

    2, widely used in textile, printing and dyeing, paint, dye, paper, ink, oil field, sewage treatment, sugar, food processing and other fields.When used in dyeing and dyeing, it has good compatibility with additives in dyeing bath, and does not affect color light and dyeing fastness.

Foam is a dispersion system with a large number of bubbles dispersed in liquid. The dispersed phase of polypropylene glycol PPG is gas and the continuous phase is liquid.When surfactant is added to the system, a layer of surfactant molecules is adsorbed on the surface of the bubble, and when it reaches a certain concentration, the bubble wall forms a solid film.Surface antistatic agent adsorbed on the gas-liquid interface, resulting in the decrease of surface tension of the liquid surface, thus increasing the gas-liquid contact surface, so that bubbles are not easy to merge.The relative density of the bubbles is much lower than that of water, and as the rising bubbles pass through the surface, they pick up a layer of surfactant molecules on the surface.Therefore, the bubble film with surfactant adsorbed in the air is not the same as the bubble film in solution. It contains two layers of surfactant molecules, forming a bimolecular film, and the adsorbed surfactant has a protective effect on the liquid film.Defoaming agent is to destroy and inhibit the formation of this film, defoaming agent into the bimolecular directional film of foam, destroy the mechanical balance of the directional film and achieve bubble breaking.

    The defoamer must be a liquid that spreads easily on the surface of the solution.This kind of antistatic agent liquid will take away a layer of solution on the adjacent surface when spreading on the surface of the solution, so that the liquid film is locally thinned, so that the liquid film breaks, and the foam is destroyed.In general, the faster the defoaming agent spreads on the surface of the solution, the thinner the liquid film becomes, the critical thickness is quickly reached, the foam destruction is accelerated, and the defoaming effect is strengthened.Generally, the liquid that can spread on the surface and play the role of defoaming has low surface tension and is easy to be adsorbed on the surface of the solution, so that the local surface tension of the surface of the solution is reduced (that is, the surface pressure is increased), and the phenomenon of imbalance occurs.Therefore, spreading occurs locally from here. At the same time, polypropylene glycol PPG will take away a layer of adjacent liquid below the surface, resulting in the thinning of the liquid film, thus destroying the bubble film.Therefore, the reason for defoaming on the one hand lies in the easy to spread, adsorption of defoaming agent molecules instead of foaming agent molecules, formed a poor strength of the film;At the same time, part of the solution adjacent to the surface layer is taken away in the spreading process, which thinns the liquid film of the foam, reduces the stability of the foam, and makes it easy to destroy.

    An excellent antistatic agent must take into account both antistatic and antifoam effects, that is, it should not only quickly destroy the foam, but also prevent the formation of foam for a long time.It is often found that some defoaming agents lose their effectiveness after being added to the solution for a certain time.To prevent the formation of foam, also need to add some defoaming agent.The reason for this may be related to whether the critical micelle concentration CMC of foaming agent (surfactant) exceeds.In solutions exceeding CMC, defoaming agents (generally organic liquids) may be solubilized so that they lose their ability to spread out on the surface and their defoaming effectiveness is greatly reduced.When defoaming agent is added at the beginning, its spreading speed on the surface is higher than the solubilizing speed, showing a good defoaming effect.After a period of time, as the defoaming agent is gradually dissolved, the defoaming effect is weakened accordingly.