The Application of dimethyl silicone oil

Dimethyl silicone oil has a large distance between the molecules and the molecular forces are much stronger than hydrocarbons. Low surface tension, high surface activity, excellent anti - foaming and good film - forming property. Dimethyl silicone oil is hydrophobic and insoluble in water. Dimethyl silicone oil has good isolation and lubrication performance with other substances. It has the ability to block moisture without affecting air permeability. Dimethyl silicone oil viscosity changes little over a wide temperature range. Excellent heat resistance and acid resistance. Stable chemical properties, high boiling point, low freezing point, as a liquid exists in a wide temperature range. Dimethyl silicone oil has good electrical properties, especially in a variety of frequency range of time factor is small, its surface tension is small. Excellent shear resistance. Based on the above excellent properties, dimethyl silicone oil is widely used in machinery, electrical, textile, coating, medicine and other sectors of the national economy.

Application in the field of cosmetics

The application of silicone oil in cosmetics began in the 1950s in the United States, in the 1960s in Japan and in the 1970s in China. However, its development and popularity have been very rapid in the past decade. Hair shampoos, care products, skin care products and make-ups are commonly used. One of the most widely used, the most is methyl silicone oil. The use of methyl silicone oil in cosmetics has the following characteristics:

1) Tasteless and colorless, without affecting the appearance and aroma of the final product;

2) Have a very good sense of agility and extensibility;

3) Good hydrophobicity and smoothness;

4) No irritation to skin, high safety to human body;

5) Good gas permeability, does not interfere with skin breathing;

6) Chemical stability, no reaction with other cosmetic raw materials.

For example, the use of medium viscosity methylsilicone oil in various skin care products can improve the extension of cosmetics on the skin, play a protective effect. Adding methyl silicone oil to the face or lipstick can improve the dispersion of the pigment, improve the stretching and use sense. Adding methyl silicone oil to mousse can improve carding. A small amount of methyl silicone oil is added to shaving cream to lubricate the skin from the blade.

Silicone oil used in cosmetics should be different from industrial products in terms of quality grade and must be carefully selected.

Application in medical and food fields

Dimethyl silicone oil has no toxicity to human body and is not decomposed by body fluids, so it is widely used in medical and health undertakings. Medical methyl silicone oil (100~1000mPa·s), the United States, Japan have special standards, China has also included in the pharmacopoeia. It is mainly used as an additive for external medicine and as an ingredient for gastrointestinal medicine, but silicone oil cannot be used in blood system. Taking advantage of its defoaming effect, the oral gastrointestinal defoaming tablet and pulmonary edema defoaming aerosol were prepared. Adding silicone oil into the ointment can improve the penetration of drugs to the skin and improve the efficacy. Some plasters based on silicone oil have a very good effect on burns, dermatitis, bedsores, etc. Using the anticoagulant effect of silicone oil, it can be used to treat the surface of blood storage device, prolong the storage time of blood samples, etc.

Methyl silicone oil is used in food production process, some countries have provisions in the food law, the use of methyl silicone oil drying range of 300~600mPa·s, and has a special grade brand. It is mainly used for defoaming, demoulding and anti-stick processing in food packaging.

Defoaming agent

Because of dimethyl silicone oil surface tension is small, and insoluble in water, animal and plant oil and high boiling point in the mineral oil, good chemical stability, and non-toxic, used as a defoaming agent has been widely used in petroleum, chemical, medical, pharmaceutical, food processing, textile, printing and dyeing, paper making industries, as long as add 10 x 10-6 ~ 100 x 10 - silicone oil was good defoaming agent.

Demoulding, anti - sticking, smoothing agent

As a demoulding agent, anti-adhesive and smoothing agent, methyl silicone oil has a long history of application in rubber products, plastic products processing, metal casting, glass products processing, paper and paper products processing, fiber production and processing and many other aspects. Its application range and dosage, still expand ceaselessly. Usually used viscosity (25℃) grade is 0.1~100Pa·s, high viscosity demoloming, adhesion resistance, smoothness; Low viscosity coating and good surface affinity, generally choose to have both these two aspects of the performance of 0.1~30Pa·s methyl silicone oil. In addition to direct use, it can also be used as solution type, emulsion type, aerosol dosage form, fat paste type.

Methyl silicone oil is widely used in fiber filament, raw cotton with oil, spinning with oil, sewing thread with smoothing agent. The oil used for raw silk and cotton is low viscosity methyl silicone oil. The smoothing agent for sewing thread is methyl silicone oil with medium and high viscosity. Using the thermal stability and low viscosity temperature coefficient of methyl silicone oil, coupled with anti-static agent, emulsifier and other oil agents, the spinning oil is used in nylon and poly cool spinning process to prevent wire breakage and loose caused by electric charge when the very fine monofilaments are sprayed from the spinneret and fast winding. Melt wire, nozzle should also use methyl silicone oil for stripping treatment to prevent carbide or melt attachment caused by broken wire.

Electrical insulation oil

Methyl silicone oil has a very good electrical insulation, heat resistance, temperature stability, cooling capacity and penetration, and other insulation material has good compatibility, so is widely used in transformers, power transformers and other special purpose vehicle of the transformer, capacitor, cable insulation oil, can make the mechanical and electrical equipment smaller, increase power, life and improve reliability. This is mainly used in the viscosity (25℃)10-1000 mpa ·s methyl silicone oil. Typical use cases are:

Transformer oil: Japan began to use methyl silicone oil as insulation oil in vehicle transformers of Shinkansen in 1973. Two vehicles are equipped with one transformer, and one transformer uses 50mPa·s viscosity silicone oil of more than 200L. In the United States methyl silicone oil (50mPa·s) by the federal standard, FM standard confirmed as high combustion point electrical insulation oil, non-combustible transformer oil, has widely replaced the use of polychlorinated biphenyls (PCB) since the 1930s for power transformers. In Europe, factories and high-rise buildings, in Southeast Asia, the Middle East and other countries in high-rise housing, residential areas, subway distribution transformers have been widely used as insulation oil. Compared with other insulating oils, silicon oil has the disadvantages of large thermal expansion coefficient, large gas solubility and high hygroscopicity. Attention should be paid to the structural design and moisture management of transformers. Methyl silicone oil as an insulating oil, Japan has JISC-2320-78R (electric insulating oil), JISC-2101-78R (electric insulating oil test method); ASTM D2225-79 in the United States. In China, Chengdu Silicone Research Center developed insulating grade methyl silicone oil for transformers in 1985, and cooperated with the mechanical and electrical department to trial-produce the first silicone oil transformer prototype, which is installed in Beijing subway and has been in operation till now. However, due to the cost of silicone oil and other factors have not been promoted, it is expected that with the development of silicone industry and technical progress of mechanical and electrical industry, it will have a good application prospect.

Capacitor oil: methyl silicone oil with a viscosity (25℃) of 50mpa·s is used in vehicle capacitors. Although silicon oil lacks corona resistance, it can be completely solved from the design.

Insulation oil for cable terminal connector box: used for 275kV xlPE cable terminal connector box insulation oil, xLPE does not swell, has been widely used.

Oil for shock absorption and damping

Methyl silicone oil has been widely used in machine manufacturing, instrument and instrument industry as shock absorption and damping oil due to its viscositytemperature performance, wide viscosity range, thermal stability and high compressibility. Typical use cases are:

1) Automobile brake fluid with relatively low viscosity methyl silicone oil (20mPa·s) as the base agent, the United States began to try out in 1967, in 1975 published FMVSS DOT standard, in 1978 published MILB46176 standard, SAEJ1705 standard. Japan established the group standard JACASB8001 in 1980. American military vehicles, snowmobiles and mail trucks have been put into use. Silicon oil brake fluid has the advantages of good thermal stability, small viscosity change, mechanical shear stability, no corrosion to metal. However, compared with ethylene glycol brake fluid, the price is high and it is not easy to popularize. Methyl silicone oil has the problem of rubber bowl shrinkage, the need to add oil improver, anti-friction agent, water capture agent, rubber swelling agent, anti-rust agent and so on. In recent years, there has been a shift from methyl silicone oil to modified silicone oil, and practical results have been obtained.

2) Damping oil for automobile engine cooling fan has been practical. More recently, Viseous Coupling oi1, with approximately 10Pa·s of drilling, has been used in 4WD vehicles to improve drive mechanism switching operations and improve performance in tight turns or in snow or mud.

3) High viscosity methyl silicone oil (tens of thousands to hundreds of thousands of mPa·s) is used for torsional vibration absorption damping of internal combustion engines used in vehicles, ships and generators, so as to improve the durability of internal combustion engines. Methyl silicone oil has a good effect as a shock proof oil for instrument. Silicone oil with proper viscosity can be selected according to the size of vibration power, which is widely used in automobile and aircraft instruments.

Coating, plastic and other materials additives

With the unique surface performance of methyl silicone oil, paint, ink to add a small amount, can prevent color uneven, improve the extension, make the film surface uniform, increase bright-coloured, smooth effect. High viscosity methyl silicone oil can also be used as a coating defoaming agent. But use method and dosage is not at that time, can produce opposite effect. The coating added with silicone oil is not compatible with other coatings and should not be mixed with each other. The amount of silicone oil is generally controlled between 0.01% and 0.5%.

Adding methyl silicone oil into thermoplastic resin can give plastics new properties. Improve the release of plastic (internal release agent) and the dispersion of inorganic filler in the resin, improve the fluidity of the resin and the surface lubrication and wear resistance of the product. POM, PA, HIPS, ABS and other resins with methyl silicone oil have been widely used to make wear-resistant and lubricated plastic parts, such as gears of OA equipment.

Dimethyl silicone oil can make many other material additives, such as whitening agent can be used as paint, add a small amount of silicone oil into the paint, can make the paint film without package, not wrinkle increase the brightness, add a small amount of silicone oil into the ink, can improve the quality of printing, add a small amount of silicone oil to the polishing oils (such as car glazing oil), can increase the brightness, protective film, and has a good waterproof effect.