This chemical company occupies the commanding heights of technology!

Recently, Cangzhou Dahua Co., Ltd. issued an announcement that the co-polysilicon PC product has been successfully commissioned for a trial run recently.

Cangzhou Dahua stated that it takes a certain amount of time for the product to be widely recognized by the market. Currently, foreign products dominate the market. After Cangzhou Dahua’s products are put on the market, it takes time to be recognized by downstream customers in terms of product quality and quality. In addition, Cangzhou Dahua also needs time. According to customer requirements, optimizing production processes and improving product quality will increase R&D investment accordingly. The production capacity of Cangzhou Dahua PC device is 100,000 tons. The production of silicon copolymer PC is a process improvement carried out on the original production line. After the production of this product, the original ordinary PC capacity is affected, and it is also limited by the current total capacity.

Copolysilicon PC is a high-end PC product with broad development space and huge market potential. The successful output of this product makes Cangzhou Dahua the first domestic enterprise to use continuous production method to produce co-polysilicon PC, filling the domestic gap in this field, marking that Cangzhou Dahua has occupied the commanding heights of PC technology and greatly enhanced The core competitiveness of the enterprise has formed a new profit growth point.

1. Introduction to Copolysilicon PC

Polycarbonate has a large rigid group of benzene ring, which limits the internal rotation of the molecular chain segment, and the strong polar group -COO (ester group) provides greater intermolecular force and binds the molecular chains to each other , Further weakening the flexibility of the molecular chain. Therefore, the glass transition temperature and melting temperature of the polymer are high, the melt viscosity is high, and the molecular chain is not easy to slip under the action of external force. In addition, since the molecular chain contains -COO (ester group), in the presence of acid or base, the ester can undergo a hydrolysis reaction to generate the corresponding acid or alcohol. Therefore, conventional PC is not stable against hydrolysis, is sensitive to notches, has poor scratch resistance, has a significant yellowing effect when exposed to ultraviolet light for a long time, and PC is easily immersed in some organic solvents.

Conventional PC and silicon-containing PC synthetic monomers both contain bisphenol A and phosgene, but silicon-containing PC is also copolymerized with polydimethylsiloxane.

In 1969, GE (now SABIC) first developed polysiloxane (PDMS) copolymer polycarbonate. There are a large number of silicon-Oxygen bonds in the polysiloxane molecule, the main chain is flexible, has good thermal stability and flame retardancy, and has selective permeability to oxygen and Nitrogen.

At present, the main companies producing silicon copolymer PC are SABIC, LG Chem, etc.

2. The advantages of introducing organosilicon groups

1) Increase flexibility

The introduction of the organosilicon group increases the length of the structural unit, reduces the rigidity of the huge benzene ring, and increases the flexibility of the molecular chain. Therefore, the fluidity of the PC material is improved.

2) Improve hydrolysis resistance

To understand why it can improve hydrolysis resistance, organosiloxane "-Si-0-Si-" is a hydrophobic group, and there is a strong chemical affinity between organosilicon compounds and inorganic silicate materials. Use this Performance can effectively change the characteristics of the surface of the material to make it water-repellent. Therefore, the organosiloxane structure is connected to the polycarbonate and its unique properties are used to greatly improve the hydrolysis resistance of the polycarbonate.

3) Improve the performance of high and low temperature resistance, flame retardant, corrosion resistance, etc.

Due to the unique structure of organic silicon, it combines the properties of inorganic materials and organic materials. It has basic properties such as low surface tension, low viscosity-temperature coefficient, high compressibility, and high gas permeability. It also has high and low temperature resistance, electrical insulation, and oxidation resistance. Excellent properties such as resistance, weather resistance, flame retardancy, water repellency, corrosion resistance, non-toxic, tasteless, and physiological inertness.

Therefore, silicone is inserted into the PC to improve the high and low temperature resistance of the PC, so that the mechanical properties at room temperature can still be maintained at -30℃~-40℃; and the oxidation resistance and weather resistance of silicone Features, improve the oxidation resistance of PC; enhance the yellowing resistance.

3. Application of copolysilicon PC

Copolysilicon PC is a special type of PC and has applications in many aspects, including 5G radome housing, new energy industry, electronic appliances, Internet of Things, and military materials.

(1) Radome shell

The 5G antenna is a device used to receive and radiate radio waves, and the radome is the outermost protective part of the antenna array. The high-frequency transmission of 5G signals is susceptible to external interference, causing serious signal attenuation. Therefore, the materials that need to be used have low dielectric, low loss, and meet the requirements of various harsh environmental conditions. Special silicon copolymer PC has the characteristics of low specific gravity, weather resistance, humidity resistance, low temperature resistance, low dielectric constant, etc., which is very suitable for 5G radome shell materials.

(2) New energy industry

Special silicon copolymer PC has excellent flame retardancy, weather resistance, low temperature resistance, and is resistant to humid environments, and has a high heat index. In the new energy industry, it is mainly used for charging guns, charging piles, photovoltaic terminals, battery diaphragms, etc.

(3) Military materials

In the military, special silicon copolymer PCs are mainly used for explosion-proof shields, helmets, butts, and radar antennas.