Dacheng Purui New Materials Co., Ltd

The preparation process of dicyclopentadiene injection resin is the first of its kind in China and has been certified for novelty search

On October 13, 2022, the preparation process of 100000 tons per year of Dicyclopentadiene Injection Resin (DCPD-RIM) developed and produced by Dacheng Purui New Materials Co., Ltd. passed the national certification of Anhui Provincial Institute of Science and Technology Information, marking the true localization and large-scale production of Polydicyclopentadiene (PDCPD) materials!

Polydicyclopentadiene (PDCPD) material is a high-performance thermosetting plastic suitable for reaction injection molding (RIM). This article briefly describes the development, characteristics, forming processes, and equipment used for this material, and introduces the properties and applications of PDCPD material developed by Dacheng Purui New Materials Co., Ltd. In addition, the prospects of PDCPD material are analyzed and forecasted.

overview

PDCPD is a thermosetting polymer material with good application prospects. In 1985, Hercules and Goodrich in the United States collaborated to industrialize this material for the first time. Representative brands include Mutton, developed in partnership between Hercules and Teijin Corporation in Japan, as well as Toluene and Pentad series developed in partnership between Goodrich and Rayon Corporation. PDCPD material has excellent physical and stable chemical properties. Compared with fiberglass, its "lightweight and high-strength" characteristics are more prominent. It can replace metals and certain engineering plastics in complex structural components such as vehicle parts, large electrical casings, medical equipment, and corrosion-resistant equipment. By adding new technologies and additives, its application fields can be expanded, resources and energy can be saved, and it can adapt to the needs of the times.

Molding process and equipment

1. Molding process

PDCPD products are generally produced using RIM technology, which is based on high-purity DCPD (≥ 98%) through ring opening displacement polymerization (Romp). The raw materials are mostly two-component systems (a, b liquids), and the process is as follows: (1) raw materials. a. B material liquid is a low viscosity liquid. A material contains DCPD, activator, and additives, while B material contains DCPD, catalyst, and additives. The viscosity is controlled at 0.2~1.0 pays and the material temperature is 20~30 ℃; (2) Mold. The mold needs to be preheated to 40-80 ℃. When the product is thick or large, there should be a temperature difference of 20-40 ℃ between the female and male molds; (3) Measurement, mixing, and injection molding. a. The mass ratio of B material liquid is 1:1, and the difference should be less than 5%; (4) Decompress and demold. When the product structure is simple, it can be self demolded. When there are reinforcing ribs or other complex structures, release agents can be used; (5) Organize and decorate. The entire production molding cycle is around 6 minutes. Figure 1 shows the molding process flowchart of PDCPD products.

2. Equipment

The equipment for PDCPD-RIM products consists of injection machines, molds, and mold closing machines. The injection machine includes a storage tank, a circulation pipeline, a metering pump, and a mixing head. The storage tank should be equipped with heating and cooling devices, as well as mixers, N2 protection systems, and automatic feeding devices. The circulation pipeline should be equipped with filters and heat exchangers, and the measurement accuracy should be controlled within ± 1.5%. The mixing head is the main component of the RIM device, which directly affects the uniformity of the material liquid mixing. In order to improve the utilization rate of the injection machine, a "one machine, multiple heads" production line can be used. The sealing and heat transfer requirements of the mold are very high, but due to the low injection pressure (generally 0.3~1.0mpa), the material and structural strength requirements for the mold are relatively low. Therefore, aluminum, aluminum zinc alloy, epoxy resin, and cast steel materials can be used as molds to reduce the investment cost of the mold. The mold clamping machine is used to fix the mold, and its clamping force, clamping accuracy, parallelism, and rigidity are all very important. PDCPD-RIM products are usually formed using a horizontal clamping system (vertical clamping can also be used according to product structure requirements).

Raw materials and material properties

1. Raw materials

At present, only Suits from the United States, Rime from Japan, and Dacheng Purui New Materials Co., Ltd. from China have achieved mass production of raw materials for PDCPD-RIM products worldwide. The high raw material prices and low market awareness in Japan and the United States have constrained their development in China. In July 2021, Dacheng Purui New Materials Co., Ltd. completed the production of 100000 tons of dicyclopentadiene injection resin annually, marking the complete localization of raw materials for PDCPD-RIM products. This has led to the withdrawal of American raw materials from the domestic market and a significant decrease in Japanese raw material prices, completely breaking the foreign monopoly on raw materials and reducing and stabilizing raw material prices. After nearly 10 years of exploratory basic research on the PDCPD-RIM formula, Dacheng Purui New Materials Co., Ltd. has overcome multiple technical difficulties and mastered the purification, liquefaction, and modification technology of DCPD, special additive preparation technology, polymerization speed regulation technology, raw material batch production technology, and PDCPD-RIM forming process technology. The performance of the developed products has reached the technical level of international similar products and has independent intellectual property rights. For the first time, it has achieved exports to Russia, Belarus, and Thailand, with some indicators leading Japan and the United States, filling the domestic gap and occupying a leading position domestically and internationally.

2. Material properties

The PDCPD material developed by Dacheng Purui New Materials Co., Ltd. has good coloring effect and excellent mechanical properties, and can achieve free design of product shape and free adjustment of molding cycle. In addition to the high mechanical properties described in the table above, this material also has excellent weather resistance, wear resistance, surface coating, electrical insulation, acid and alkali resistance, and waterproofing.

application area 

PDCPD material has excellent performance, low equipment cost, short molding cycle, high production efficiency, stable product quality, and friendly working environment. It is suitable for the production of batch and multi variety products of various scales, and therefore has a wide range of applications. Here are some application examples.

1. Sewage purification tank

With the increasingly serious problem of water pollution, various countries have introduced relevant policies requiring domestic and production wastewater to be self-produced, self managed, and recycled. Therefore, the demand for sewage purification tanks has increased sharply. At present, sewage purification tanks are mostly made of fiberglass, which has defects such as low production efficiency, poor working environment, and serious environmental pollution. Therefore, some developed countries have banned the use of fiberglass purification tanks. In this situation, there is an urgent need for a material to replace fiberglass, and PDCPD material has attracted attention in the application field of sewage purification tanks due to its series of excellent properties: it can be formed in one step, has high production efficiency, and belongs to the category of "environmentally friendly materials"; Excellent corrosion resistance ensures its long service life; High strength ensures that it can withstand sufficient water pressure and can produce large, different thickness, and structurally complex molded products; The high degree of production automation reduces labor costs.

2. Equipment pipelines in the chlor alkali industry

In the process of chlor alkali production, salt water corrosion, alkali corrosion, acid corrosion, and chlorine gas corrosion coexist, becoming the major victims of corrosion. However, the annual demand for chlor alkali in China reaches tens of millions of tons, so there is an urgent need for anti-corrosion materials to improve the corrosion resistance of equipment, extend its service life, and ensure safe and stable continuous production. The commonly used materials for chlor alkali plants include carbon steel, cast iron, stainless steel, copper and copper alloys, nickel and nickel alloys, titanium and titanium alloys, etc. Carbon steel and cast iron are inexpensive and easy to obtain, but have poor corrosion resistance, while other metals are expensive. In contrast, PDCPD products can effectively solve the problems of chlor alkali manufacturers. They have a wide range of solvent corrosion resistance and can work in high-temperature media between pH 0 and 14; Easy to form and meet the design requirements of chlor alkali plants; Excellent corrosion resistance can greatly extend the service life of equipment pipelines; Compared to nickel and titanium metals, it is cheaper. Therefore, PDCPD-RIM products can be widely used in the chlor alkali industry.

3. Sanitary products

Ceramic bathroom products have dominated the bathroom market for many years due to their pure white texture, dense structure, high strength, and good thermal stability. However, they have two disadvantages: (1) high brittleness, low impact resistance, and fragility; (2) Ceramics have a certain degree of water absorption, and after absorbing water, they expand, causing cracks in the glaze surface. PDCPD products will not experience similar problems, and their high impact resistance ensures long-term safe use of the product. In addition, PDCPD material also has other advantages: excellent coating performance, flexible and diverse artistic design, which can meet customers' personalized needs; One step molding with high production efficiency; The product design has no joints, and both safety and comfort are satisfactory; Environmentally friendly and pollution-free.

4. Medical equipment

Recently, led by the Ministry of Industry and Information Technology, several major ministries such as the National Development and Reform Commission and the Ministry of Science and Technology are studying and formulating policy measures to accelerate the development of the medical device industry. Relevant plans are expected to be released within the year. Market participants believe that the demand for medical equipment is expected to increase significantly in the next five years. However, the manufacturing technology of medical equipment in our country is backward, and the materials are mostly stainless steel, which is heavy and easy to conduct heat, with poor structural integrity, limiting the development of high-quality medical equipment. PDCPD material can be used to prepare medical equipment with light weight, large volume, and spatial structure. Moreover, the product has low thermal conductivity and high electrical insulation. After adding a certain amount of flame retardant, it can also meet the national flame retardant requirements for indoor plastics. Based on these excellent characteristics, PDCPD materials can provide guarantees for the innovative development of medical equipment in China.

5. Kayaking

With the improvement of China's quality of life and the planning and construction of tourism facilities in Hainan International Tourism Island and developed coastal areas, the shipbuilding industry in China will have a significant development in the coming years. At present, the fiberglass material used in ships has a low rigidity modulus, while PDCPD belongs to high rigidity and high modulus materials, which can be formed in one step, have good overall integrity, have no joints or gaps in the shell, are lightweight and high-strength, and have great potential for reducing structural weight. In addition, due to its simple molding process, it is more labor-saving than steel and wooden boats, and has better mass production performance. The use of PDCPD material can also effectively reduce the cost of kayaking.

6. Vehicles

PDCPD can replace metal or fiberglass and be applied to vehicle shells and other components. Its advantages are: light weight, easier transportation and assembly, and can reduce the labor intensity of workers on the production line, reduce vehicle fuel consumption, and increase vehicle load capacity; Small investment, short production cycle, and quick results; The vehicle shell can achieve free design of appearance, making it more diverse and personalized; The surface roughness of the shell can reach Class A almost without any treatment before painting; Excellent coloring, electroplating and aging resistance.

7. Other applications

The low density, high strength, high hardness, high impact resistance, and excellent corrosion resistance of PDCPD material make it suitable for manufacturing large garbage bins, replacing wood to prepare logistics pallets with larger loads and more durable use, as well as high-strength, high impact resistant, large-area thin-walled components such as air drop boxes. The excellent low-temperature characteristics (no brittleness of the material at -40 ℃) make it suitable for manufacturing snowmobiles. PDCPD materials still have great application prospects in fields such as sports equipment, new energy vehicles, large electrical enclosures, and aviation manufacturing.

prospect

At present, dozens of PDCPD-RIM product production lines have been built in China, mainly focusing on the shells of large machinery such as engineering vehicles and agricultural vehicles. After market testing, customers have a high level of recognition for the product. Some application areas are also under development, such as sewage purification tanks and medical equipment, and there are also some application areas that need to be developed (such as sports equipment), so the market potential of PDCPD products is relatively large.

In recent years, environmental factors have led some developed countries to strictly control the use of fiberglass products, and PDCPD belongs to the category of "environmentally friendly materials". The standardization of national environmental policies, the strengthening of citizens' environmental awareness, and the improvement of market awareness provide opportunities for the rapid development of PDCPD products. The localization of raw materials has enhanced the competitiveness with foreign brands, further reduced raw material prices, stabilized the supply of goods, provided high-quality technical services, and thus increased the profit margin of domestic product manufacturers. It can be foreseen that PDCPD will achieve breakthrough growth in multiple application areas.