Hydroxyl silicone oil is a silicone material polymerized from siloxane monomers and has a hydroxyl group at the end of its molecular weight. Its structural formula is as follows:

HO-Si(CH3)2 O[Si(CH3)20]nSi(CH3)2-OH.

The hydroxy silicone oil with a viscosity of 250mPa.S or more is called 107 silicone rubber. In addition to the general properties of methyl silicone oil, it also has the reactivity of hydroxyl. It can be used to make some new materials or cross-linked into elastomers (or membranes).

Hydroxy silicone oil is a colorless, transparent liquid with good electrical insulation and temperature resistance. It has a high flash point, low freezing point, which can be used for a long time under the condition of -50℃~ +250℃. It has the characteristics of low viscosity-temperature coefficient, high compression rate, low surface tension, good hydrophobicity, and moisture resistance. It is chemically inert and physiologically inert.

Ⅰ. Technical indicators of hydroxy silicone oil

1. Appearance: it is a colorless and transparent liquid.
2. Viscosity (25℃, mpa.s): 25~100000 (can be customized according to user requirements).
3. Hydroxyl content (%): 8.5-9 (directly related to viscosity).

Ⅱ. The use of hydroxy silicone oil

Hydroxyl silicone oil can be used in different industries according to the hydroxyl content and viscosity.

1. Products with medium and high viscosity are used as the base glue of paper anti-sticking agent, and the cured film has an excellent anti-sticking effect. It is widely used in label bottom paper and asphalt packaging paper, sealing paper tape bottom paper, decoration paper bottom paper, etc.

2. Used in the power and electrical industry as the main component of insulating paint or as a component of insulators.

3. Used as the base rubber, and diluent of condensation type room temperature vulcanized silicone rubber, such as the base material of sealant and mold rubber.

4. It can be used instead of dimethyl silicone oil, and it is easy to emulsify.

5. Small molecular hydroxy silicone oil (25~30CP, hydroxyl content is about 8%) is the structure control agent of silicone rubber. Using it to replace diphenyl dihydroxy silane simplifies the processing technology of silicone rubber and improves the processing performance (omit Heat treatment). It also increases the transparency of products and improves working conditions.

Ⅲ. Usage and dosage of hydroxy silicone oil

Hydroxy silicone oil is generally combined with a curing agent to achieve cross-linking and curing. When used for release paper, it must be fixed with a coupling agent. Typically, the curing agent amounts to 3% to 5% of the base gum, and the coupling agent accounts for the base gum—0.5%~1 %. The base gum is diluted ten times with a solvent in most cases. The curing agent and coupling agent are added. The mixture is evenly stirred and then coated on the surface of the substrate and cured at room temperature or by heating. It takes more than 30 minutes at room temperature and 30 seconds for heating at 120~150℃. No solvent is needed for sealant and mold gum base. After adding the curing agent, stir evenly (the curing agent used for one-component and two-component is different), and it can be cured within 30 to 120 minutes after deaeration.

Ⅳ. The precautions of hydroxy silicone oil

Hydroxy silicone oil should not be mixed with acid-base substances, alkoxysilanes, and water vapor at high temperatures. Otherwise, it will tend to solidify and change viscosity.

Ⅴ. Packaging, storage, and transportation of hydroxy silicone oil

1. Hydroxy silicone oil should be sealed and stored in clean plastic barrels and should not be in contact with strong acids and alkalis;

2. Store at room temperature in a ventilated and shady place.