In recent years, the application and development of modified polysiloxane research work has attracted much attention in the silicone market, and epoxy-modified polydimethylsiloxane is one of them. Epoxy-modified polydimethylsiloxane (epoxy-modified silicone oil or epoxy-based silicone oil) is the product of partial substitution of methyl groups (including side and end positions) by epoxy groups in methyl silicone oil molecules. Dimethylsiloxane has the characteristics of high surface activity, good chemical stability and heat resistance, and the introduction of epoxy groups gives it special reactivity, adsorption and cross-linking, making epoxy-modified silicone oil in fiber finishing, resin modification, light-curing anti-viscosity isolation agent, coating additives and other fields have a wider range of applications.
I. Synthesis of epoxy-modified silicone oil
Epoxy modified silicone oil is usually made by the addition reaction method of allyl glycidyl ether and silicone oil containing Si-H bond in the presence of platinum catalyst, i.e. silicon-hydrogen addition. In addition to the addition method, other commonly used synthesis methods include the soxhlet method and the ring-opening addition method.
Silicon-hydrogen addition method.
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Process flow.
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Second, the application of epoxy modified silicone oil
1.Fiber finishing agent
Epoxy modified silicone oil is also used as a large number of fiber finishing agent, can give the fabric durable smoothness, softness, resilience and fullness, etc., can improve the wrinkle resistance and can significantly improve the sewability of the fabric, and the treatment of the fabric after the high temperature is not yellow, fiber expansion, mainly for white or light-colored fabric soft finishing.
Epoxy modified silicone oil is used as an auxiliary in the production of spandex oil, in the treatment of spandex fibers, can prevent the adhesion between spandex fibers. Used as cotton, wool, silk, hemp fabrics and products finishing, can make it have a feather-like silky feel, washable, non-yellowing.
Polyether epoxy modified silicone oil, because there are a variety of active groups in the molecular chain, can be cross-linked with the hydroxyl, amino groups in the fiber in the baking process, not only can make the fabric light, thin, smooth, soft and good air permeability and drapability, but also improve hydrophilicity and antistatic, and has a real silk style, so that the fabric is comfortable to wear, smooth, especially suitable for polyester imitation silk and other imitation silk fabric finishing.
2. Resin modifier
Epoxy resin is a thermosetting polymer material with excellent mechanical strength and bonding properties, good heat resistance and molding processability, and low cost, thus becoming the main material for today’s semiconductor packaging. However, epoxy resin has the disadvantages of high internal stress, resulting in poor flexibility and high temperature resistance, low ductility and easy to produce cracks. The use of epoxy modified silicone oil as an internal additive for epoxy resin materials can effectively improve the internal stress of epoxy resin products and enhance their flexibility, so that they are not brittle and do not crack.
3. Coating additive
Acrylic acid, methyl methacrylate, butyl methacrylate and styrene co-polymerization into water-based anti-corrosion coatings, the reaction if the addition of epoxy modified silicone oil, can make such coatings both organic and inorganic coatings of high hardness, strong adhesion and wear resistance and other advantages. Epoxy/fluoro co-modified silicone oil can improve curing efficiency, enhance dissolution, and flame retardant, used in fiber optic coatings, electronic packaging coatings, etc. Epoxy base/olefin oxide co-modified silicone oil is used in coatings, printing inks or varnishes to improve gloss, peel properties and wetting properties. The addition of epoxy-based silicone oil to coatings can improve the weathering, chemical resistance and environmental corrosion resistance of coatings.
4. Light-curing anti-viscosity isolating agent
Epoxy modified silicone oil in cationic catalyst, curing occurs by UV irradiation, so that the epoxy group with ring tension opens to form a tension-free ether bond, and its initiation mechanism does not involve free radicals and excitation of the trilinear state, and thus oxygen infinite aggregation effect. Good adhesion to most substrates, small volume shrinkage, even zero, suitable for light curing of thick films and color paints. In the molecular chain of epoxy-based modified silicone oil, the most suitable number of epoxy groups is 3%~25% of the whole number of silicone oxygen chain links. Now the epoxy modified silicone oil UV curing system is more and more widely used, become the mainstream products in the cationic light curing system, a large number of pressure-sensitive adhesive products for the production.
5. Other applications
As a plastic additive, epoxy modified silicone oil can improve the formability of plastics, so that the lubricity of the surface of plastic products, release, and flame retardancy is improved. Compared with the addition of non-reactive dimethyl silicone oil, it also shows better printability, anti-static and anti-fouling effects.
