Application and Formulation of silicon Modified Epoxy Resin

Silicon modified epoxy resin finds various applications due to its unique properties and performance characteristics. The ratio of polysiloxane to epoxy resin plays a crucial role in determining the resin's overall performance. A high epoxy resin content enhances product adhesion but may compromise heat resistance. On the other hand, polysiloxane products with higher twist content exhibit excellent heat resistance and electrical properties but may experience decreased adhesion and formability. Therefore, it is important to identify the optimal ratio of siloxane to epoxy in silicone epoxy resin through formula experiments.

The use of benzoic acid as a catalyst aids in reducing the condensation temperature. Experimental results demonstrate that benzoic acid can effectively react with silicone alcohol and epoxy resin at temperatures ranging from 160-180 °C. A 500mL scale condensation reaction of 10-126 can be completed under these conditions. However, at an expanded experimental scale of 3000mL, the condensation reaction progresses at a significantly slower rate, with a maximum time of up to 18 hours. This is primarily due to the insolubility of benzoic acid in the input raw materials and toluene, as well as its tendency to sublime at 100 °C. Hence, benzoic acid is not considered an ideal catalyst for this purpose.

The generation of organic silicone epoxy resin is primarily achieved through two condensation reactions: the dehydration reaction between the light groups in silicone alcohol and epoxy resin, and the reaction between the ethoxy group in silicone alcohol and the light group in epoxy resin. According to available data, it has been reported that polydimethylphenylethoxysilane and phenyltriethoxysilane readily react with epoxy resin at temperatures ranging from 170-180 °C. Under specified conditions, ethanol remains as the volatile substance during the reaction.

[Example 1] In a mixed solvent of propylene glycol monopropionate and xylene, bisphenol A epoxy resin and Y-aminopropyltriethoxysilane are added and reacted at 60 °C for 3 hours. Subsequently, PhSi (partially hydrolyzed condensation polymer of 0Me origin and MeSiC OMe)3 is added to the reaction mixture, followed by further reaction at 60 °C in the presence of water and isopropanol for 3 hours. Aluminum tripolyphosphate, y-epoxypropoxypropyl trimethoxysilane, dibutyltin dilaurate, pigments, and other additives are then added to the obtained resin. When applied to steel sheets and air dried at room temperature for 7 days, the resulting coating exhibits good color retention even after exposure to 300 hours of sunlight, one year of outdoor storage, or 100 hours of salt water testing, with a light retention rate of 96%. This demonstrates excellent corrosion and weather resistance. Additionally, partially hydrolyzed polycondensate of Huliu propyl trimethoxysilane, PhSiCOMe)3, MeSi(OM is prepared by adding BCOEt to propylene glycol monopropyl cheese and xylene, followed by reaction at 60 °C for 3 hours. Epoxy resin, preservatives, stabilizers, pigments, fillers, and other components can be added to the resulting product to achieve excellent corrosion resistance and weather resistance.

For instance, the addition of aminopropyltriethoxysilane and epoxy resin dropwise to MeOH and SiCOEt)4 results in a product that exhibits good adhesion, chemical resistance, scratch resistance, and water resistance after curing at 110 °C for 30 minutes. A coating made of epoxy modified silicone resin containing silica, when subjected to boiling water testing, remains crack-free for 90 days, demonstrating its intact nature.

Furthermore, epoxy modified silicone resin can be prepared through various methods, such as pre-curing epoxy containing polysiloxane with epoxy resin, co-condensation of ammonia-containing polysiloxane with epoxy resin, and others.

[Example 2] The silicone modified epoxy resin used for heat-resistant and anti-corrosion coatings typically contains a silicone content of 50%.

Here is an operational method for the preparation: Add an appropriate amount of xylene, cyclohexanone, and n-butanol to a resin melting pad equipped with a jacket and reflux condenser. Fill the condenser with water and the jacket with steam. Initiate stirring and gradually raise the temperature to 70 °C. Then, add the E-20 epoxy resin to the pad in batches and melt it. Finally, raise the temperature to 90 °C and maintain it until complete melting is achieved. Cease heating and allow the mixture to cool to 30-40 °C before filtering, loading, and storing.

In the resin reaction system equipped with stirring, thermometer, reflux condenser, and oil-water separator, add epoxy resin solution and organosilicon oligomer solution. Stir the mixture and heat it at 180-190 °C. Ethanol will precipitate during the reaction. Take samples and measure the gelation time on a 200 °C electric heating gelation plate. If the gelation time reaches 3-5 seconds, it indicates that the reaction has reached its endpoint. Cease heating, cool the mixture to below 120 °C, and then add xylene for dilution. Stir the mixture thoroughly, filter it, and store it in barrels once the temperature drops to 30-40 °C. The solid content of this modified resin solution is 50%.

Experiments have revealed that in the reaction between organosilicon oligomers (such as polyphenylmethylethoxysiloxane) and epoxy resin modification, only the light groups in the epoxy resin participate in the reaction, and the number of epoxy groups remains relatively unchanged. Therefore, this modified resin solution can be cured into a film using amino resin as a crosslinking agent at high temperatures (200 °C), or polyvinyl amine or low molecular weight polyamide as a crosslinking agent at room temperature.

Our company specializes in the production of various silicone-based products, including Silicone Resin Adhesive, Silicone Resin of mica plate, Silicone Resin Emulsion, Silicone Resin Intermediate, Silicone Resin for Coating, silicone coating resin, Silicone Resin Paint, Silicone Modified Acrylic Resin, and more. If you have any inquiries or require further information regarding silicone oil or silicone resin, please feel free to contact us.