It refers to materials processed by specific equipment such as matrix resin, reinforcing materials (fillers, glass fibers), functional additives (coupling agents, release agents, toughening agents), mainly unsaturated polyester composite materials , phenolic molding compound, epoxy molding compound, epoxy potting compound, epoxy casting compound, epoxy glass fiber cloth, etc. Its characteristics are: high strength, high electrical performance, good formability and so on.

The silane coupling agent contains a siloxane group that can react with an inorganic binder, an epoxy group, an aminovinyl group, and the like that can react with an organic resin. As a commonly used additive in composite materials, its function is to improve the wettability of the matrix resin to the slug and glass fibers, so that the matrix resin is connected with the slug or glass fibers through chemical bonds, thereby improving the flexural strength and impact of the composite material. Strength, water resistance, electrical properties, etc.

Toughening silane coupling agent refers to a flexible long chain with a certain molecular weight between the siloxane group and the organic active group. Due to the existence of flexible long chains, the chemical bonding density of the surface layer of the ballast in the composite material is appropriately reduced. When the composite material is impacted by the outside world, the flexible chain wrapped on the surface of the ballast can absorb the impact energy well. This improves the impact strength of the composite and reduces stress cracking. At the same time, since most of the long-chain silane coupling agent is dispersed in the surface layer of the filler, and the content in the resin layer is small, the thermal deformation temperature and glass transition temperature of the composite material have little effect under the appropriate dosage.

The composite material added with toughening silane coupling agent has high toughness and low internal stress, but the heat resistance is not greatly reduced. Compared with general silane coupling agents, long-chain silane coupling agents also have unique advantages in improving the wettability of glue to fillers, especially for those fillers with high surface energy such as glass fiber. , nano=silica, etc. The long-chain silane coupling agent greatly reduces the surface energy of the filler due to its hydrophobic and flexible long chain, so that the solvent, resin, and auxiliary in the glue can penetrate into the glass fiber uniformly. It can be dispersed evenly on the surface of the nanofiller, which improves the impact strength, heat resistance, etc. of the composite material. When the glass fiber cloth treated with a general silane coupling agent is coated with glue (such as epoxy glass fiber prepreg for copper clad laminate production), due to the capillary phenomenon, acetone, = methyl alcohol in the glue on the surface of the fiber cloth are always Low-molecular-weight polar solvents such as methylformamide diffuse preferentially in the glass fiber, which makes the viscosity of the glue on the surface of the fiber cloth increase sharply, and it is difficult for the resin and curing agent in the glue to quickly penetrate into the glass fiber. The composite material has poor impact stsrength and heat resistance. In addition, glass fiber composites treated with long-chain silane coupling agents have also been shown to have better resistance to ion migration.

Due to the influence of the long chain, the reaction speed of the toughened silane coupling agent and the filler or the silanol bond on the surface of the glass fiber is slightly slower, so it is necessary to appropriately prolong the processing time of the slug.