Chemical name: 3-acetoxypropyltrimethoxysilane
CAS number: 59004-18-1
Molecular structure: 
Molecular formula: C8H18O5Si
Molecular weight: 222.31
Product Overview:
KH-5775 is an acetoxysilane. Its molecular structure has an acetoxy functional group containing an unsaturated double bond structure and three hydrolyzable alkoxy groups (methoxy). This double reaction The activity allows them to increase the degree of bonding, adhesion and compatibility between the two materials through two-way chemical reactions with inorganic materials (glass, metals, fillers) and organic polymers (thermosetting resins, plastics, elastomers). The mechanical properties of resin-based composite materials or improve the adhesive strength and water resistance of resin coatings. At the same time, this product can also be copolymerized with acrylic acid, methacrylic acid, vinyl acetate, styrene and other monomers containing unsaturated double bonds to give the copolymer moisture curing and good adhesion and water resistance. In different applications, they can be used as coupling agents, adhesion promoters, crosslinking agents, surface modifiers of pigments and fillers, silicone modified graft comonomers, etc.
KH-5775 is trimethoxysilane, its hydrolysis rate is significantly faster than triethoxysilane KH-5775, which can provide faster reaction and curing speed, but the side reaction of its hydrolysis reaction is methanol, which is slightly less environmentally friendly.
Reaction characteristics:
In the presence of water, the alkoxy groups of KH-5775 will be hydrolyzed to form active silicon hydroxyl groups, and at the same time, methanol, a by-product of the hydrolysis reaction, will be released. This silicon hydroxyl group will undergo a condensation reaction with the hydroxyl groups on the surface of various inorganic materials (substrate, pigments and fillers) to form a chemical bond; and their acetoxy groups can be unsaturated with other The acrylic acid, methacrylic acid, vinyl acetate, styrene and other monomers of the copolymer are copolymerized, or under the action of peroxide initiation, they are added to the newly initiated unsaturated double bond on plastic, rubber or resin so that all or Partially cross-linked and cured resin. Through the above two-way reaction, the product realizes the coupling and connection between the inorganic filler (or substrate) and the organic polymer material, or the silanization graft modification or crosslinking of the resin.
The hydrolysis of KH-5775 requires the use of organic acids (such as formic acid, acetic acid, etc.) as a catalyst. Specifically, the pH of the water is adjusted to about 3.5 to 4.5, and then the silane is added and stirred for a period of time (at least 30 minutes) until the silane is completely dissolved , The solution is clear and transparent. Their hydrolysates are unstable and it is recommended to use them within 24 hours. The fogging of the solution indicates that the silane has partially self-polymerized to form a silane polymer (silicone) and has failed.
Its aqueous solution can significantly reduce the surface energy, such as 0.9% KH-5775 silane aqueous solution can reduce the surface energy from 72 dynes/cm to about half. This indicates that the hydrophobic organic portion of the silane forms an alignment layer at the gas/liquid interface.
When processing mineral fillers, minerals can be blended with silane under high-speed shear without adding any solvent. After the silane treatment, the treated substrate or mineral surface should be briefly dried at 104-121°C to complete the polycondensation of silanol and remove a small amount of methanol or ethanol formed during the hydrolysis of methoxysilane.
Inorganic materials suitable for this product include silicon materials such as glass, glass fiber, glass wool, mineral wool, mica, quartz, and metals such as aluminum hydroxide, magnesium hydroxide, kaolin, talc, steel, zinc, aluminum, and their oxidation However, it has no effect on fillers that do not contain hydroxyl groups on the surface, such as calcium carbonate, graphite, carbon black, and barium sulfate.
Suitable polymers for this product include (but are not limited to) unsaturated polyester resins, peroxide vulcanized rubber such as EPR, EMDP, silicone rubber, styrene butadiene, natural and other peroxide vulcanized rubber, peroxide cross-linked Plastics such as PE, PVC, etc.
Typical uses:
1. This product can improve the mechanical and electrical properties of thermosetting and thermoplastic resins reinforced with glass fiber and containing inorganic fillers, especially those thermosetting resins (such as unsaturated polyester, polyurethane and Acrylate), peroxide vulcanized rubber (EPR, EPDM, silicone rubber, etc.) and thermoplastic resins (including polyolefins and thermoplastic polyurethanes).
2. This product can significantly improve the dry and wet mechanical strength and electrical properties of unsaturated polyester composite materials filled with inorganic fillers (such as cast or die-cast artificial quartz stone, etc.).
3. This product can be copolymerized with vinyl acetate, acrylic or methacrylic monomers to synthesize silane-modified polymers that can be cross-linked and cured at room temperature. Such polymers are widely used in coatings, adhesives and sealants to provide excellent adhesion Relay and durability.
Packing: 20 kg carton packaging, containing 4 5 kg plastic drums; or 25 kg plastic drums, 210 liter standard steel drums and IBC ton drums.
Storage conditions and shelf life:
Store indoors in a dark place, keep ventilated, cool and dry. Make sure that the lid is well sealed and can effectively isolate the air. The water in the air will react with it, which will cause it to hydrolyze, polymerize and deteriorate. The shelf life of the original packaged products is one year, and expired products can only be used after passing the test.
Mobile version