Chlorinated polyvinyl chloride (CPVC), also known as perchlorethylene, is a new polymer elastomer material between rubber and plastic produced by chlorination of polyvinyl chloride (PVC) , is an important modified variety of PVC, with an appearance of white or light yellow powder, chlorine content of 61 to 68%, viscosity of 1.3 to 1.6 (mPa·s), particle size (40 mesh sieve pass rate) ≥98%, thermal decomposition Temperature ≥100℃, thermal stabilization time (120℃) ≥40 seconds, oil absorption rate ≥20%. C PVC has excellent resistance to chemical corrosion such as acids, alkalis, salts, fatty acid salts, oxidants and halogens. In addition, CPVC also has excellent aging resistance, surface activity, electrical properties and flame retardant properties, and can be extruded through powder blending or injection molding through pellet mixing, making it widely used in construction, chemical industry, metallurgy , shipbuilding, electrical appliances, textiles and other fields have a wide range of uses. 1. Production methods of CPVC At present, the production process of CPVC can be divided into two categories: homogeneous chlorination process and heterogeneous chlorination process. The specific production methods include solution chlorination method, aqueous phase suspension chlorination method and gas-solid phase chlorination method. Three methods. The solution chlorination method (homogeneous chlorination) is a traditional method for preparing CPVC. The loose PVC resin is treated with an appropriate solvent (tetrachloroethane, dichloroethane or chlorobenzene), and then heated at 80 to 100 The initiator azobisacetonitrile is added at ℃, and CPVC is generated by chlorination through chlorine. It generally includes five processes: chlorination of polyvinyl chloride, filtration of chlorinated solution, sedimentation of CPVC from the solution, drying of CPVC and solvent recovery. The reaction of this method is uniform and the product is easy to process. The disadvantages are that the process flow is too long, solvent recovery is difficult, the production cost is high, and there is certain pollution to the environment. The aqueous suspension method (heterogeneous chlorination) is to suspend PVC in water or hydrochloric acid aqueous solution medium, and chlorine it in the presence of initiators and other chlorination aids to obtain heterogeneous CPVC. It includes three processes: polyvinyl chloride chlorination, CPVC washing and stabilization, and CPVC drying. The production process of this method is simple, the production process is short, the chlorine content of the product can reach 67%, has good heat resistance and mechanical properties, and the production cost is also low. The disadvantage is that the acidic waste gas generated during the production process needs to be treated. The solid phase chlorination method is to chlorine solid polyvinyl chloride in a fluidized bed under the trigger of ultraviolet rays or elemental fluorine to obtain chlorinated polyvinyl chloride. This method has a simple process flow, but the operation is complicated, the chlorination process is difficult to control, and the product uniformity is poor. 2. Uses of CPVC As a new chemical material with excellent performance, CPVC has a wide range of uses, mainly in the following aspects. (1) Used as structural materials. When pipes made of CPVC are used to transport hot water and corrosive media, they can still maintain sufficient strength when the medium temperature does not exceed 100°C. CPVC is one of the few polymers that ensures that pipes can be used in both high temperature environments and high internal pressures. Since the mass density of CPVC is only 1/6 of brass and 1/5 of steel, and its thermal conductivity is extremely low, pipes made of CPVC are light and do not require thermal insulation to reduce heat loss and can be used as Hot waste pipes in chemical plants, electroplating solution pipes, thermochemical reagent delivery pipes, wet chlorine gas delivery pipes in chlor-alkali plants, etc. Since the heat resistance of CPVC is close to the temperature of boiling water, CPVC injection molded parts can be used for joints of water supply pipes, filter materials, dehydrators, etc. Because CPVC has self-extinguishing properties and good insulation properties, it can also be used to produce electrical or electronic parts, such as wire ducts, protective shells for conductors, electrical switches, protective covers for fuses, and electrical insulation materials for cables. CPVC can be rolled into films to manufacture chemical-resistant and corrosion-resistant chemical equipment such as reactors, valves, etc. It can also be used to manufacture rubber or hard rubber-lined storage tanks in the electrolysis industry. (2) Used to make composite materials. CPVC composite materials composed of CPVC and certain inorganic or organic fibers have excellent impact resistance, heat resistance and tensile strength. They can be used to make plates, pipes, corrugated plates and special-shaped materials. wait. (3) Used as coatings and adhesives. Since CPVC has good solubility in organic solvents such as acetone and chlorinated hydrocarbons, CPVC (or with other resins) and solvents can be combined to make adhesives for different uses. The mixture and coating have high bonding strength and are easy to construct. The CPVC coating has good film-forming properties, good color and high adhesion.
CPVC resin paint has excellent chemical stability, acid and alkali resistance, and is also very stable against alcohol, lubricating oil, oxygen, ozone, etc. It also has very good water resistance, making it particularly suitable for use in humid areas. CPVC paint has good fire resistance and good cold resistance, and can maintain good mechanical properties in cold areas. If a PVC film with a thickness of 0.05~0.15mm and printed with wood grain on the back is hot-pressed on a CPVC board with a thickness of 0.25~0.40mm (chlorine content is greater than 60%), then use a hot melt adhesive to make the CPVC board and The wooden surface is bonded, and the resulting decorative board has very good dimensional and thermal stability at high temperatures, will not soften, and can obtain beautiful and durable decorative effects. (4) Used as a foaming material. The heat resistance of CPVC foam is better than that of PVC foam. The shrinkage rate at high temperatures is quite small. It can be used as an insulation material for hot water pipes and steam pipes. This kind of foam material has good mechanical strength, electrical insulation and high temperature resistance, so it can be used as a raw material for building materials, electrical parts and chemical equipment. CPVC with a chlorine content of more than 60% has very good retention of solvents, so CPVC can be foamed in solvents that can produce gas when heated, such as hydrocarbons, ethers, ketones, etc. with boiling points of 50 to 160°C. The solvent is used as a foaming agent to produce uniform, microporous foam. (5) For the transformation of chlorine fiber, the washing temperature of domestic chlorine fiber should not exceed 60°C. In order to improve its heat resistance, adding 30% CPVC when spinning chlorine fiber can greatly improve the heat resistance of the product, and The shrinkage rate can be reduced from the original 50% to less than 10%. (6) Used as a plastic modifier. Blending CPVC with thermoplastic or thermosetting plastics can improve the properties of these materials. For example, blending C PVC into PVC in a certain proportion can significantly improve the heat resistance of PVC. (7) Others After spinning, CPVC can be used as fishing nets, work clothes, industrial filter cloth, non-combustible parachutes, and the outer covering of submarine cables. Underwear made of CPVC fiber can prevent and treat rheumatoid arthritis. In addition, CPVC can also be made into transparent materials and used as carriers to make polyethylene glycol phase transfer catalysts, etc. 3. Domestic and foreign production and market conditions of CPVC In the 1930s, the former West German AG Law Company successfully developed CPVC using the solvent method and put it into production. In the 1940s, the British ICI Company conducted research on the aqueous suspension method. Many companies such as DuPont in the United States also conducted research on this method and applied for a large number of patents. In the late 1950s, the American company B.F. Goodrich first produced CPVC using the aqueous suspension method and achieved industrial production in 1961. Subsequently, the United Kingdom, France, Belgium, Japan, the former Soviet Union and other countries also successively developed the aqueous suspension method to produce CPVC and established CPVC production devices. At present, the production of foreign CPVC is mainly concentrated in several economically developed countries such as the United States, Japan, Germany, the United Kingdom and France. The production technology is also monopolized by them and a complete CPCV application system has been established. Before 1995, the world's CPVC was mainly monopolized by the Goodrich Company of the United States. It was not until September 1995 that the subsidiary of Japan's Jonyon Chemical Company in Houston, USA, began selling CPV C, which began to break the monopoly of Goodrich Company of the United States. CPVC’s monopoly position. So far, more than 20 companies around the world produce CPVC, with a total production capacity of about 70,000 tons/year. The main manufacturers include Goodrich Company of the United States (production capacity of 34,000 tons/year) and Tokuyama Seiki of Japan. Water Company (production capacity is 20,000 tons/year), Zhongyuan Chemical Company and Germany's BASF Company, among which the production of the United States and Japan accounts for about 80% of the world's total CPVC production. The products mainly include 7 types: resin base, casting resin, molding or extrusion materials, organosol or plastisol, blends, powders, solutions, emulsions or dispersions.
In my country, in the 1960s, Jinxi Chemical Research Institute successfully developed CPVC using solution method and realized industrial production. In 1963, Shanghai Electrochemical Plant also used solution method to successfully develop CPVC and passed technical appraisal. In the mid-1970s, Anhui Province Chemical Research Institute The institute succeeded in developing CPVC using the water-phase suspension method, and designed a 500-ton/year capacity based on a 60-ton/year pilot scale. In 1985, Wuxi Chemical Group Co., Ltd. began to study the liquid-phase suspension chlorination method to produce CPVC. In 1987, a 100-ton/year CPVC production line was built. Later, the Hubei Provincial Chemical Industry Research Institute conducted research on the gas-solid phase production of CPVC. At present, the total production capacity of CPVC in my country is about 6,500 tons/year, and the output is about 6,000 tons/year. The products are mainly used in the paint industry. The situation of major CPVC manufacturers in my country is shown in Table 1. Table 1 Main manufacturers of CPVC in my country Unit: tons/year Manufacturer name or site Production capacity Process route Jinhua Chemical (Group) Co., Ltd. 2000 Solution method Shanghai Chlor-Alkali Chemical Co., Ltd. 1000 Solution method Shandong Weifang Chemical Plant 300 Aqueous phase Method Jiangsu Wuxi Electrochemical Plant 100 Suspension method Wuhan Gedian Chemical Plant Jianhan Branch 100 Gas-solid phase method Anhui Wuhu Chemical Plant 100 Aqueous phase method Jiangsu Taicang 200 Solution method Jiangsu Changzhou 300 Solution method Yibin Tianyuan Chemical Industry Group 500 Solution method Beijing 500 Solution method Jiangsu Nanjing 1000 Aqueous phase method Compared with foreign countries, there are still some gaps in my country's CPVC industry, which are mainly reflected in: (1) The scale of CPVC production equipment is too small, the production cost is high, and the product quality and performance are not very good; (2) There is insufficient research on the ingredients of CPVC, too few product brands, and a narrow application range; (3) The promotion and application of CPVC is not enough. At present, the products are mainly used in the paint industry and have few applications in other industries. Due to the low quality of my country's CPVC, narrow application scope, and insufficient application development efforts, the sales of CPVC products produced in China are not smooth. However, CPVC used in pipes, hard products, etc. relies heavily on imports, which has seriously affected the development of my country's CPVC. As a new type of polymer material, CPVC has the characteristics of wide operating temperature, light weight, good flame retardant performance, corrosion resistance, etc. Its application in building materials, chemical industry and other industries is developing rapidly, and the market potential is huge. The current world consumption has reached 110 Thousands of tons/year. Since the performance of CPVC is significantly better than that of PVC in some fields, and with the development of CPVC stabilizers and modifiers, its application market will make great progress. If 1% of PVC in my country is replaced by CPVC, the domestic market demand for CPVC will reach 20,000 tons/year. If 10% of PVC is replaced by CPVC, the market demand will reach 200,000 tons/year. Therefore, The future CPVC market prospects are very optimistic. Relevant domestic enterprises should actively organize efforts to strengthen the research on C PVC stabilizers and modifiers, and at the same time expand the production of suspension method and gas-solid phase CPVC, expand production capacity, and continuously improve product quality and reduce production costs to improve its international reputation. competitiveness in the domestic market. Follow-up question: - -! Does the abstract of this thesis title have any references? . . If so, I'll throw you away! Answer: Sorry, this is what I have learned. There are no references on the Internet. This is complete enough. If you want to add more, please see below. CPVC is a new engineering plastic with broad application prospects. Resin comparison index PVC CPVC density (g/cm3) 1.38—1.45 1.45—1.58 Vicat softening temperature (℃) 72—82 90—125 Tensile strength (MPa) 39—58 54—70 Flexural strength (MPa) 105 120 Linear Thermal expansion coefficient (K-1) (6-7)×10-5 (7.5-8)×10-5 Elongation at break 120 50 Storage and transportation: This product should be stored in a dry and ventilated warehouse, and the stacking height should not be More than 10 bags, protect from sun and moisture. Transportation must be carried out in clean and covered vehicles to protect it from sunlight, rain and heat. This product is non-toxic and non-dangerous.
Specifications and technical indicators 30 mesh sieving rate Volatile content ≤0.30 Chlorine content % 66~69 4 Thermal decomposition temperature ℃ ≥110 5 Thermal stability S ≥20 Application★ Pipe material: CPVC is mainly used for the production of pipes, transporting hot water and corrosion It is a flexible medium that can maintain sufficient strength when the temperature does not exceed 100 ℃, and can be used for a long time under high internal pressure. The weight of CPVC is 1/6 of brass and 1/5 of steel, and has extremely low thermal conductivity. Therefore, pipes made of CPVC are light in weight, have good thermal insulation performance, and do not require thermal insulation. ★ CPVC pipes can be used as hot sewage pipes in factories, electroplating solution pipes, thermochemical reagent delivery pipes, and wet chlorine gas delivery pipes in chlor-alkali plants. ★Injection molded parts: CPVC resin can produce pipe fittings for water supply pipes, filter materials, dehydrators, etc., as well as electrical and electronic parts. Such as wire troughs, protective layers of conductors, electrical switches, protective covers of fuses, insulation materials of cables, etc. ★ Rolled sheets: can be used to manufacture chemical and corrosion-resistant chemical equipment, such as reactors, valves, electrolyzers, etc. ★ Composite materials: CPVC composite materials composed of CPVC and certain inorganic or organic fibers have good impact resistance and better heat resistance than other resin composite materials. They can be made into plates, pipes, corrugated plates, special-shaped materials, etc. ★ CPVC can be used to modify chlorine fiber: the washing temperature of domestic chlorine fiber should not exceed 60 ℃. Adding 30% CPVC when spinning chlorine can greatly improve the heat resistance of the product. The shrinkage rate is from the original of 50% dropped below 10%. ★Foam material: The heat resistance of CPVC foam material is better than that of PVC foam material. The shrinkage rate at high temperatures is quite small, and it can be used as an insulation material for hot water pipes and steam pipes. CPVC with a chlorine content of more than 60% has good solvent retention. CPVC can be foamed in a solvent that can generate gas when heated to obtain uniform, microporous foaming gas. It can be used with a boiling point of 50-160 ℃. Hydrocarbons, ethers, aldehydes and other solvents are used as foaming agents. ★Others, mixing CPVC with thermoplastic or thermosetting plastics can significantly improve the physical and mechanical properties of these materials, such as improving the heat resistance of products. ★ In foreign countries, CPVC with higher impact resistance and better transparency has been prepared through the improvement of production technology. This transparent material can be used in automobiles, optical discs, and audio-visual products, and has good economic benefits.