Prospects of Organic Fluorine Chemical Workers in China

Organic Fluorine Industry Outlook for Organic Fluorine Chemicals in China Huang Yuguo (Shanghai Tianyuan International Trade Co., Ltd.) As organic fluorine materials have some unique and unmatched properties, the development of new chemical materials industry and related industries in China Significant influence. In recent years, due to the destruction of the earth's ozone layer by the important intermediates of organofluorine and the product's HCFCs, countries around the world are gradually phasing out the use of HCFC products. How to develop organofluorine compounds has become an important topic discussed by experts. Organic fluorine materials mainly include HCFCs and substitutes, fluoropolymers and their processed products, and fluorine-containing fine chemicals (People usually use hydrogen fluoride, which is the main raw material for organic fluorine industry, also included in organic fluorine products).

1 CFCs and substitutes mainly deplete the ozone layer (ODS), which is the controlled substance of the Montreal Protocol on Substances that Deplete the Ozone Layer (hereinafter referred to as the “Protocol”). In 1991, China joined the amended Protocol. In January 1993, the State Council approved China's implementation of the "Protocol" "China's ozone depletion substances phase-out country program" (hereinafter referred to as "national program"), which was obtained in March 1993 by the "Protocol" Multilateral Fund Executive Committee. Recognition. Therefore, during the Ninth Five-Year Plan period, the development of HCFCs in China is faced with a more complex situation: On the one hand, perfluorochlorocarbons (CFCs) with high ozone depletion potential (ODP) will gradually reduce the consumption, until 2010. In the year, the production and consumption of ODS (mainly CFCS in China) is completely phased out; on the other hand, substances with lower ODP values ​​such as F22, n41B, and P142B (ie, hydrochlorofluorocarbons (HCFCS)) are transitional substitutes. During the "Ninth Five-Year Plan" period, not only can it be cut, but also properly developed to ensure a smooth transition from high ODP substances to low-ODP substances to zero ODP substances in the process of reducing ODS production and consumption.

In addition, substances with zero ODP, such as F134A, F152A, etc. (ie hydrofluorocarbon-containing HFCS), are substitutes, and the pace of scientific research and development and industrialization must be accelerated to meet domestic demand.

According to the "National Plan", China will gradually reduce ODS consumption from now on. Fll, F12, F113, etc. with high ozone depletion potentials will be reduced first, and F22, H41B with low ozone depletion potential as a transitional substance will have greater growth in 2000 to compensate for the reduction in Fll, H2, The use of vacancies caused by H13, etc., will be eliminated when new substitute production, development, and production capacity are met.

According to our country's situation, in the "Ninth Five-Year Plan" period, it is necessary to carry out the construction of substitutes for low ozone energy consumption value substitutes for ODS substitutes, and also to construct alternatives with zero ozone potential value. While striving for the grants from the Multilateral Fund, it must also pay attention to the research and development of domestic technology and do a good job in building alternative devices. At the same time, the development and application of other non-HCFC alternatives such as cyclopentane, isobutane, dimethyl ether, etc. should also be accelerated.

2 Fluoropolymers and Their Processed Products The organic fluorine industry in China was developed in the late 1950s to meet the urgent needs of the continuously developing defense industry and cutting-edge science and technology. After 30 years of efforts, a relatively complete system and categories have been formed, from scientific research to production, from raw material support to applied products, and a certain amount of development capabilities and technical foundations have been established. At present, fluoropolymers produced in China mainly include polytetrafluoroethylene (PTFE), polyfluorinated ethylene propylene (FEP or F46), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE) and fluorine rubber. In 2000, the demand for fluoropolymer PTFE, other fluororesin, and fluororubber in China was 7,000 tons, 1,700 tons, and 1,100 tons respectively, totaling 9,800 tons.

Organic fluorine industry China has a considerable amount of PTFE imports each year. In 1994, China's PTFE imports amounted to 1,744 tons, and its export volume was 434 tons, with a net import volume of 1,310 tons. In 1995, PTFE imports amounted to 1,187 tons, while export volume was 598 tons, and net import volume was 589 tons. As far as the production of fluoropolymer production plants in China is concerned, PTFE accounts for a large proportion, close to 90%, while other fluorine-containing resins and fluoroelastomers account for only a little more than 10%, and the ratio is seriously out of balance. In contrast, at present, the global PTFE resin accounts for about 51.3% of the total fluoropolymer production capacity, other fluorine-containing resins account for 38.6%, and fluoroelastomers account for 10.1%. In view of domestic PTFE varieties, the general performance is poor The ratio of particle suspension resin accounts for more than 60%, while the proportion of fine-particle suspension resin with better processing performance is less than 40%, which directly affects the development of PTFE products and product grade improvement. In addition, from the perspective of the production of PTFE products, the types and types of PTFE products are relatively complete, but there are many general-purpose products, and there are relatively few fine-sized and ultra-small-sized fine products and special-purpose products. Therefore, special attention should be given to the development of copolymerized products of organic fluoropolymers and other polyolefins and blended resins to develop a variety of organic fluoropolymer applications.

In view of this, we should not blindly expand PTFE production capacity in the future, but should focus on the development of other fluoropolymers such as PVDF, FEP, and fluoroelastomers to meet the pillar industries and industries of the national economy such as automotive, electronics, petrochemical, construction, and pharmaceuticals. demand. In terms of PTFE, the focus should be on reducing unit consumption, improving product quality, and increasing product grades. At the same time, the PTFE product structure should be adjusted, focusing on the development of fine-grained suspension resins, dispersion resins, and concentrated dispersions. Support the development of the fluoropolymer product processing industry and further develop the market.

3 Fluorine-containing Fine Chemicals Fluorine-containing fine chemicals mainly refer to fluorine-containing intermediates, fluorine-containing pharmaceuticals, fluorine-containing pesticides, fluorine-containing surfactants, and various fluorine-containing treatment agents. There are many types of fluorine-containing intermediates, of which the most important ones and the output of products that account for more than 90% of the production of fluorine-containing intermediates are aromatic fluorides, which is also the direction and focus of future development of fluorine-containing intermediates.

Aromatic fluorides have been used to produce fluorine-containing pharmaceuticals with special curative effects due to the introduction of fluorine atoms with low steric hindrance and strong electrophilic capacity, which not only maintains their original characteristics but also greatly increases their activity. It is an effective, broad-spectrum, low-residue pesticide and fabric finishing agent that is resistant to water, stains, sunlight, and organic solvents.

At present, there are more than ten major categories of aromatic fluorides developed at home and abroad. Nearly one thousand varieties are used. The main types are as follows: fluorine (A) benzenes, trifluorotoluenes, bromobromofluorofluorobenzenes, and nitrofluorocarbons. Benzene, Fluoroanilines, Fluorophenols, Fluorobenzaldehydes, Fluorophenones, Fluorobenzoic Acids, Fluorobenzoyl Chlorides, Fluoroanisole, Fluoropyridines, etc. In the above-mentioned fluorides, most of them are industrially produced in Europe, the United States, and Japan. In China, only fluorobenzenes, trifluorotoluenes, chlorofluorobenzenes, fluoroanilines, nitrofluorobenzenes, and fluorobenzoic acids Compounds are produced in small batches or industrially. More than half of China's fluorine-containing intermediates are actually exported into the international market, mainly in Europe, the United States, Japan and other countries. Therefore, the development of fluorine-containing fine chemicals should grasp two aspects during the “Ninth Five-Year Plan” period: first, continue to vigorously explore the international market; second, vigorously develop domestic fluorine-containing pharmaceuticals, fluorine-containing pesticides, and fluorine-containing surface active agents. Such downstream fluorine-containing fine chemical products not only raise economic benefits, but also open up the domestic market for fluorine-containing intermediates.

Organic fluorine compounds have a wide range of applications in medicine and pesticides. At present, the marketable anti-infective drug norfloxacin is a fluorine-containing organic compound, and other fluorine anesthetic agents such as HALOTHANE, PENTHRANE, ETHRANE, ISOFLURANE, etc. are all organic anions with less anesthetic effect and no post-anesthetic effect. 5-Fluoride Urea, HALOTESTIM, etc. have been used for the treatment of cancer, HALOPERIOLOL is used for sedation, SULINDAC is used for the treatment of rheumatic arthritis, and FLUMELRAMIDE is used as a diuretic. The fluorine atom in the oleophilic group in which the fluorosurfactant is a hydrocarbon surfactant is partially or completely substituted with a fluorine atom, which is characterized by good temperature resistance and chemical resistance, and the surface tension of the aqueous solution is extremely low. The extremely low concentration has a good surface activity, so its use is much less than hydrocarbon surfactants, and can be widely used in various sectors of chemistry, metals, photography, and fibers.

The production of fluorine-containing fine chemicals in China is currently around 4,000 to 5,000 tons, including perfluorooctanoic acid, perfluorotributylamine, and chlorofluorobenzene organofluorine industrial products.

4 Hydrogen cyanide Hydrogen fluoride is the raw material for the synthesis of organic fluorine products such as hydrocarbons, fluoropolymers, and fluorine fine chemicals. Therefore, the development of hydrogen fluoride products must be considered when considering the development of organic fluorine industry.

At present, the total global hydrogen fluoride production capacity is 1.3 million tons/year and the annual output is 1.1 million tons. In developed countries, the production scale of single sets of equipment is above 10,000 tons. China's industrial production of hydrogen fluoride began in 1956 and has so far gone through a 40-year history. At present, there are more than 20 hydrogen producers in China and the output reached 90,000 tons in 2000.

On the surface, China's hydrogen fluoride production capacity can meet the needs, but in fact only China's hydrogen fluoride manufacturers, Shandong Dongyue Chemical Group, Zhejiang Juhua Group and Jinan Chemical Plant and several other production capacity in the 10,000-ton or more, most The manufacturers are all in the class of 1000 or even 100 tons. The equipment capacity is low, the unit consumption is low, the product quality is poor, the pollution is serious, and the waste residue is hard to handle. According to the principle of “supporting the superior and supporting the strong” proposed by the State Economic and Trade Commission, during the “Ninth Five-Year Plan” period, there should still be planned several key enterprises with good foundation and close to economic scale, such as Dongyang Chemical Plant and Juhua Group. Jinan Chemical Plant and Shanghai Electrochemical Plant carried out technological transformation to further expand the scale, reduce unit consumption, and improve product quality. At the same time, a batch of small devices will be eliminated naturally under the influence of market economic laws, making the hydrogen fluoride industry in China a new level.

From the "Tenth Five-Year Plan" in Zhejiang Province, we can see how the province has set the priorities for the adjustment and development of fluorine chemical workers in order to raise the comprehensive competitiveness of fluorine chemical workers and achieve sustainable development.

Zhejiang is an important fluorine chemical production base in the country. The fluorochemical production value accounts for about 42% of the national counterparts, and ODS substitutes (halon substitutes), fluorine refrigerants, halon extinguishers, resins and processed products, fluorine medicines, pesticides, fluorocarbons (CFCs) and inorganics have been realized. The large-scale production of fluoride salts and other products is at the leading level in China. However, the structural contradictions among the fluorine chemical workers are still outstanding. Compared with the advanced level in foreign countries, the technological process, variety structure, and enterprise scale of fluorine chemical workers are far apart; the development of chemical industry is increasingly subject to strong pressures for the sustainable development of resources and the environment; The greater challenge of competition and intellectual property protection. To this end, Zhejiang Province determined the focus of structural adjustment and development of fluorine chemicals during the "Tenth Five-Year Plan" period.

The development goal of the fluorine chemical industry during the “Tenth Five-Year Plan” period in Zhejiang Province is: To achieve the end of the “Tenth Five-Year Plan”, the province’s total annual output value of fluorine chemicals will increase by 20%; 60% of its production technology will reach the international advanced level in the mid-1990s. 15% reached the international advanced level, 90% reached the domestic advanced level in the same period: the key technical equipment of key enterprises reached the international advanced level in the 1990s; the rate of production of new products reached 20% The key points for structural adjustment and development of fluorine chemical workers in Zhejiang are: 1. Speed ​​up Develop fluororesin, improve product quality, and expand application areas. Focusing on the development of melted fluoropolymers and fluoroelastomers, we will expand PTFE production and varieties, improve product quality and quality, and meet the demand for fluoropolymers in the automotive industry, electronic appliances, information, construction, and home appliances industries. Focus on the development and introduction of industrial technologies for the production of fusible fluororesins and industrial production technologies for fluoroelastomers (especially the research and development of fluoroether rubbers and the industrialization of fluorosilicone rubber with excellent low-temperature resistance); focus on the development of PTFE. The modified technology and modified series of products, polymerizing reactor engineering in the field of PTFE production amplification and mass transfer heat transfer optimization, post-treatment process improvement, initiator improvement and other technologies.

According to the provisions of the “Amendment to the Montreal Protocol on Substances that Deplete the Ozone Layer” and the “China’s National Programme for Phase-out of Ozone Depleting Substances”, relying on the National ODS Alternatives Engineering Technology Research Center, it will focus on the development and application of ODS substitute production technologies, focusing on the development of HFC134a. Wait for a batch of mature products to realize industrialized production; Actively promote the application of information technology in the production of ODS substitutes, realize the automation of production processes, the intelligentization of control technologies, stabilise and improve product quality, reduce raw material consumption and “three wastes” "Emissions, maintaining ODS alternative f development and production in the domestic leading position.

3. Continuously develop new varieties containing fine chemicals. Focus on the development of fluorine-containing intermediate products, fluorine-containing pharmaceuticals and pesticides end products, fluorine-containing surfactants, paint products, etc., to drive the development of related industries.

Accelerate the use of new chemical synthesis technologies, catalytic technologies and control technologies, optimize and improve production processes, research and development of nitrogen trifluoride production technologies, synthetic technologies containing special varieties of aromatic compounds, and fluorine-containing fabrics (turned to page 59). The industry is a thermogravimetric plot of various coating samples consisting of different compositions and included in the composition as conditioning-charger copolymer salts. According to the study, the initial decomposition temperature of all coating samples is greatly limited by the heat treatment temperature of the synthetic fluoroplastic coating (sintering at 260~265). For Fluoroplastic-3 at 430X: almost total loss due to thermal decomposition of the polymer to gaseous products. Although the addition of copolymer salt to the fluoroplastic composition compared to pure fluoroplastic-3 (middle curve 7 and curve 8) allows the initial decomposition temperature to drop from 360 to 340T, the composition coating is still thermally stable. This is basically similar to the case of fluoroplastics.

Adding pigments and metal oxides (Zn0, Cr203) to the fluoroplastic-3+CPR composition can increase the thermal stability of the coating. The addition of the metal powder not only greatly increases the thermal stability of the composition, increases the decomposition temperature, but also results in a greater amount of material remaining in the coating with the metal powder compared to the composition without the filler during thermal decomposition: Fluoroplastics -3 * 1. Fluoroplastics - 3 + CPR 4 Conclusions It was concluded that the electrical factors play an important role in the formation of polymer coatings on the electrodes.

It has also been concluded that the properties of the pigments and fillers not only have a great influence on the electrodeposition process itself, on the protective properties of the fluoroplastic composition coating, but also give a great improvement on the thermal stability. At the same time, it has also been found that the deposits of the electrodeposited coating are distributed evenly and coated tightly. In fact, there are no penetrating pores, and the migration of the corrosive active material through the comprehensive coating can only be through the diffusion pathway.

Mu Wen (above page 49) synthesis technologies such as surfactants and other surface active agents, and key technologies for ambient temperature curing of fluorine-containing coatings.

4. Promote the development of inorganic fluorides in the direction of refinement and purification. The focus will be on the development of a vapor phase process for the production of hydrogen fluoride and ammonia; the development of products such as high-purity hydrofluoric acid BV-I grades for use in the etching of VLSI circuits and lithium hexafluorophosphate for cell phone batteries. Limit the use of the more polluted liquid phase process to produce hydrogen fluoride. Focus on supporting the development of serialized, quality-reduced, and low-polluting inorganic fluoride products by upper-scale enterprises, rectifying and shutting down a batch of inorganic fluoride producers that do not have production conditions, and promoting the orderly development of inorganic fluorides.

5. Improve the production efficiency of anhydrous hydrogen fluoride and realize large-scale production. Relying on existing production facilities, strengthening technological transformation, continuously reducing consumption, raising production efficiency, and achieving large-scale production. To prevent low-level redundant construction, the province will no longer build new 5,000 tons/year of anhydrous hydrogen fluoride production facilities.

In short, organic fluorine chemicals are strategically important industries, and it is expected that a relatively long period of time will be one of the fastest growing and most promising industries in the chemical industry. Fluorine chemical products are widely used in chemical, mechanical, construction, electronics, energy, environmental protection, information, bio-pharmaceutical, military and other fields because of their excellent chemical resistance, low temperature resistance, aging resistance, low friction, and insulation.

China is a country with large reserves of fluorspar, which is an advantageous condition for the development of organic fluorine chemical workers in China. However, this is also the reason why small and medium-sized enterprises and township and village enterprises across the country engage in organic fluorine chemicals. Various factors have caused the majority of small and medium-sized enterprises in the organic fluorine industry in China, with small scale, single consumption, poor quality, and serious pollution. The products have extremely poor competitiveness.

There are many varieties of organofluorine industrial products, but they are closely related to each other. For example, the main raw materials are hydrogen fluoride, F22 is the raw material of TFE, and TFE is the raw material of PTFE, FEP and fluororubber. The deeper the processing, the processing The more technical content, the greater the difficulty and investment.

Because all fluorine-containing waste water and waste residues in organic fluorine chemicals are difficult to manage, it is difficult to develop a single species alone, there are no supporting products before and after, and there are few series products, which are vulnerable to market fluctuations, and the relative investment is relatively low. The pollution is difficult to handle. It directly affects the competitiveness of products and the economic benefits of enterprises. From a long-term point of view, the development of organic fluorochemical workers is focused on fluoropolymers and fluorochemicals.