BK-7801 low-molecular hydroxyl silicone oil
Boctok, as a leading enterprise in the field of silicone in China, launched low molecular Hydroxyl Silicone Oil-40cs, which is becoming a "star additive" in rubber, automobile, chemical, textile and other industries due to its excellent performance and wide range of application scenarios.
1. Product introduction
1.1 Product overview
Boctok Low Molecular Weight Hydroxyl Silicone Oil-40cs is a low-molecular-weight, moderate-viscosity silicone compound. It contains an active hydroxyl group (o) at the end of the molecular chain, which combines the excellent performance and reactivity of silicone oils, and is widely used in textile, cosmetic, industrial lubrication, and rubber and plastic processing.
This product has the advantages of high permeability, dispersion, heat resistance and environmental friendliness, and is widely used as a structure control agent in Silicone Rubber processing. It can effectively control the structure interaction between the compound and silicone, improve the processing efficiency of silicone rubber, extend the shelf life of rubber, and reduce the reforming time, gel formation volume, rubber moment viscosity, vulcanized rubber hardness, and permanent deformation.
1.2 product properties
Appearance: colorless transparent fatty liquid
Viscosity (25°): 40° 5° with
Hydroxyl content: 4 %
Volatile substances (150 /3h): 18 %
Refractive index: 1.4040~1.410040 cs
Low VOC and total body cycling!
2. Application in rubber mixing parts
Boctonite low molecular weight hydroxyl silicone oil - 40xn plays a vital role in rubber preparation and processing due to its unique chemical structure and physical properties. Below is a detailed description of its application based on its mechanism of action, specific application scenarios, benefits, and precautions.
2.1 mechanism
Lubricant and dispersion: Low molecular weight hydroxyl silicone oil with low viscosity (40 ± 5 cSt) gives it excellent viscosity, can uniformly penetrate the rubber matrix, reduce the internal friction between rubber molecules, and improve the technological fluidity of rubber. At the same time, its hydroxyl group (o) can form hydrogen bonds with the surface of fillers (such as silicon and carbon), promoting the dispersion of fillers in rubber, reducing agglomeration, and improving mixing efficiency.
Internal mold release function: In the mixing process, hydroxyl silicone oil can be used as an internal mold release agent, moving to the surface of the rubber, forming a very thin lubricating film, reducing the adhesion between the rubber and the metal rollers or molds, avoiding sticking to the rollers and improving the continuity of production.
Promoting cross-linking and modification: The active hydroxyl group of silicone oil can be linked to certain functional groups in rubber (e.g., silicone rubber in SI-o or hydrogenated silicone oil in SI-n) by condensation reaction to help control the cross-linking density and optimize the mechanical properties of vulcanized rubber. In addition, in the silicone rubber system, hydroxyl silicone oil can also be used as a structural control agent to suppress the structural effect (i.e., "agglomeration compaction") caused by hydroxyl
2.2 Specific application scenarios
2.2.1 Improving the efficiency of data processing
Reducing the viscosity of the Mooney: In natural rubber (NR), styrene butadiene rubber (SBR) or EPDM and other high viscosity rubbers, adding 1%~3% hydroxyl silicone oil can significantly reduce the viscosity of the Mooney rubber compound, reduce the energy consumption of the equipment, shorten the mixing time.
Reduce the risk of burnout: by reducing the generation of surface heat, slow down the burning process during mixing, especially when processing highly filled compositions.
2.2.2 Filler dispersion enhancement
Dispersion of silica: In Silicone Rubber (e.g. VMQ) or solubilized styrene butadiene rubber (SSBR) for green tyres, hydroxyl silicone oil combines with the silicon hydroxyl group on the surface of silica, weakening the hydrogen bonding between fillers, preventing the formation of filler network, and enhancing the reinforcing effect.
Carbon black dispersion: In carbon black-filled natural rubber (NR) or styrene-butadiene rubber (SBR) system, hydroxyl silicone oil is used as a dispersing additive to reduce carbon black aggregation and improve the homogeneity and mechanical properties of the rubber.
2.2.3 internal release and surface modification:
In EPDM or NBR oil-resistant rubber seals, adding 0.5%~1.5% hydroxyl silicone oil can reduce the rubber in the opening machine or refinery in the sticky roller phenomenon, while ensuring the smoothness of the vulcanized rubber coating, reduce the subsequent use of releasing agents, improve production efficiency and reduce production costs.
3. Application in molding rubber
3.1 Mold removal and lubrication
Mechanism: The molecular chain of hydroxyl silicone oil is short, strong migration, can form a dynamic insulating film on the surface of the mold, reduce the adhesion between rubber and mold (the friction coefficient can be reduced by 30%-50%).
Data support: Adding 1-3% hydroxyl silicone oil 40xc can reduce the ejection force by 40%-60%, which is especially suitable for complex mold structures (such as precision electronic component encapsulation molds).
Limitation of side effects: Excessive addition (>5%) may result in surface oil deposits on the product, requiring improved compatibility by dynamic vulcanization or combination with gas phase silica.
3.2 increasing the fluidity of the adhesive
Low viscosity significantly reduces the meniscal viscosity of rubber (ml (1+4) at 100°C can be reduced by 10-20 points) and shortens the molding cycle (for example, the molding time of EPDM rubber from 180 to 150°C). During the vulcanization stage at high temperatures (150-180°C), hydroxyl groups can combine with the peroxide cross-linking system to form CI-O-C bonds, which increases the cross-linking efficiency (the cross-link density increased by 5%-8%).
3.3 Optimization of filler dispersion
Hydroxyl and silicon dioxide, as well as other silicon hydroxyl groups, are present on the filler surface (SiO-O) to form hydrogen bonds, reducing the likelihood of filler agglomeration. Experiments show that adding 2% hydroxyl silicone oil can improve the dispersion of carbon black/N330 in silicone rubber to achieve uniform distribution at the nanoscale.
4. Other uses
Fire retardants, personal care, paper processing, textiles, rubber manufacturing, rubber and plastic processing, automotive, leather, coatings and paints.