General situation of the development and current situation of polyurethane

The development of polyurethane has gone through more than 70 years , if we count from the synthesis of isocyanate, we have to push it forward almost a century. As early as 1849, German chemist Wurz prepared aliphatic isocyanates. In 1850, German chemist Hoffmann synthesized phenyl isocyanate. However, it was not until 1937 that Dr. Otto Bayer of the German Farben Company first used isocyanates for polyurethane synthesis. He used hexamethylene diisocyanate and 1,4-butanediol to react to produce a polyurethane fiber named lgmid-U. Polyurethane elastomer was obtained by reacting 0.00% toluene diisocyanate and various polyols. In 1942, German chemist Pitting first reported an isocyanate rubber called "i-Rubber". This kind of rubber is synthesized from polyol adipate and diisocyanate, and has a urethane cross-linked structure. It is said that in the same year, the British company ICI used polyester and MDI to produce a mixed polyurethane rubber named Valcaplon-A. The industrialization of polyurethane also started in Germany. 1941~In 1942, Bayer Company began pilot-scale production of TDI and established a device with a monthly output of 10 tons to produce polyurethane products such as rigid foam, coatings and adhesives. In 1947 the first machine for the production of polyurethane foam was developed. After 1950, the production of mixed polyurethane and cast polyurethane began, with the brand name Vulkollan. Therefore, it can be said that Germany laid the chemical and industrial foundation for the development of polyurethane in the world.

The United States isResearch on the synthesis of isocyanates and polyurethanes began in the early 1940s and made progress, but application development did not attract attention. It was not until the end of World War II and the United States' inspection of German technology and intelligence that this new field aroused great interest among American scientists and entrepreneurs. Since then, the pace of development has been accelerated and fruitful results have been continuously achieved. In 1952, Goodyear, Nach and DuPont collaborated to commercialize TDI, creating conditions for the development of polyurethane. In 1953, the production of flexible polyurethane foam was realized. The following year, the one-step process began to produce soft foam to replace latex foam in mattresses and cushions. Subsequently, Goodyear successfully developed the isocyanate-vulcanized polyurethane compound Chemiqun°-SL. In 1954 and 1959, DuPont launched tetrahydrofuran polyether compound Adiprene*-B and casting adhesive Adiprene-L, and gradually replaced hard rubber with CPU. During this period, General Tire and Rubber developed another compound, Genthane°-S. In 1959, tetrahydrofuran polyether and MDI entered the market. Subsequently, MDI-type rubber compounds, castable rubbers and thermoplastics were commercialized. In 1960, Goodrich first realized the industrial production of thermoplastic polyurethane, and its trade name was Ethane. In 1961, Mobay Company commercialized semi-thermoplastic polyurethane under the brand name Texin°. In the early 1960s, the company also first developed MDI prepolymers and its casting glue, with the brand name Multithane°-F. With the introduction of MDI and CFC, the technology of using molded foam to produce whole-skin foam products has been successfully developed, accelerating the development and application of polyurethane microcellular elastomers. In short, by the 1960s, the United States gradually formed a complete industrial system from raw material production to the development and processing of polyurethane and its products, and achieved a leading position in the world's polyurethane industry.

Japanese polyurethane industry It was mainly developed through technology introduction and joint ventures with foreign companies. Polyurethane production began in the early 1960s. In 1990, Japan's polyurethane consumption reached 625,000 tons. After that, annual consumption not only did not increase, but actually declined. In 1996 it dropped to 406,200 tons. then grew slowly. From 1998 to 2005, Japan's annual consumption hovered around 600,000 tons. In 2004, it was 617,000 tons, only an increase from 19982%.

After the 1970s, 17.68% research on polyurethane Development has entered a new era with the goals of high performance, high efficiency, low pollution and energy saving. Environmental protection, safety and green technology have become the mainstream of today's social and economic development, and are also the focus of polyurethane material research and development, and significant technological progress has been continuously made. Among the most notable achievements in the field of polyurethane elastomers are the following.

1,In 1970, liquid injection molding and reaction injection molding began to be used to produce polyurethane microcellular elastomer ports. In 1974, the United States began to use RIM technology to produce large-scale polyurethane products such as automobile bumpers and interior parts. After 1980, it successfully developed glass fiber reinforced reaction injection molding and structural reaction injection molding technologies. This is one of the lowest energy consuming process technologies and expands the application fields of polyurethane elastomers andIn terms of polyurethane production and processing technology, product quality and quantity, and polyurethane research and development level, our country lags far behind developed countries. It has basically not formed large-scale production and has not achieved full-system industrialization. In 1977, the national annual production capacity of polyurethane was only 11,000 tons, and the actual output was less than 5,000 tons. After that, the development of polyurethane in my country entered the right track of combining self-reliance and the introduction of foreign advanced technology. Since the early 1980s, raw materials and polyurethane product production technology have been continuously introduced from abroad, and cooperation and technical exchanges have begun. In 1984, Yantai Synthetic Leather Factory introduced 3,200t/year polyester polyol, 3 million square meters/year polyurethane synthetic leather and 10,000 tons/year MDI equipment from Dainippon Ink and Japan Polyurethane Company respectively. Shenyang Petrochemical Plant, Tianjin Petrochemical Plant No. 3, Shanghai Gaoqiao Petrochemical Plant No. 3, Jinxi Chemical Plant and other enterprises introduced propylene oxide polyether devices and put them into production one after another after 1987. Lanzhou Yinguang Chemical Materials Factory imported a 20,000 tons/year TDI device from the German BASF company and put it into operation in 1992. In the 1980s, Tianjin Plastic Products Factory introduced 8 production lines including flat-top foaming, vertical foaming, flame composite, sandwich panels, automobile molded seat cushions, shoe soles and thermal insulation sleeves, forming an annual output of 10,000 tons. Production capacity of polyurethane products. After 1984, Nanjing Rubber Factory, Shanxi Chemical Industry Research Institute and other units successively introduced more than 10 pouring machines, multiple horizontal centrifugal molding machines and other polyurethane and product production and processing equipment. With the import of foreign raw materials and production technology, the development of polyurethane in our country has been greatly accelerated and the overall level of polyurethane research, development and industrialization in our country has been improved. In 1990, my country's polyurethane consumption reached 117,000 tons, rose to 270,000 tons in 1993, and soared to 560,000 tons in 1997, exceeding Japan's production that year. The average annual growth rate in 7 years reached 25%. The development speed has not slowed down since then, reaching 900,000 tons in 2000 and soaring to about 6 million tons in 2010.

my country’s economy The rapid development has brought rare opportunities to the development of my country's polyurethane industry. However, by the turn of the century, the production of MDI and TDI, the main raw materials for polyurethane in my country, was still far from meeting domestic demand, and the situation that MDI and TDI were basically dependent on imports has not changed. There is no domestic industrial production of PTMG, the main raw material of spandex, and the production and sales of domestic polyurethane prepolymers have not yet formed a market scale. These have seriously restricted the development of the polyurethane industry and become the biggest bottleneck affecting the development of my country's polyurethane industry. Under this circumstance, Yantai Wanhua’s 10,000-ton MDI plant is in urgent need of expansion and upgrading, and foreign countries do not sell technology to our country. In the 1990s, four sets of TDI production units with a total capacity of 70,000 tons introduced in Baiyin, Shanxi, Cangzhou, Hebei, and Shanghai were also plagued with problems and could not operate normally. At this critical juncture, they did not retreat and wait, but strengthened their confidence, faced the difficulties, and determined to take the road of independent research and development and innovation. Yantai Wanhua overcame many technical difficulties and finally mastered the core technology of MDI production with an annual output of more than 100,000 tons, becoming the fourth country after Germany, the United States, and Japan to have independent intellectual property rights for MDI production technology. Their newly built 160,000-ton unit in Daxie Island, Ningbo was put into operation in 2005. The expanded 120,000-ton MDI plant in Yantai was put into operation in 2006. At the end of 2009, Gansu Yinguang Chemical Group Co., Ltd. finally had its own production technology for 100,000 tons of TDI. In the same year, my country's PTMG production capacity reached 235,000 tons, with an output of 120,000 tons. In 2010, the production and sales of polyurethane prepolymers and paving materials produced by Shandong Zibo Dongda Yinuowei Polyurethane Company reached 30,000 tons, occupying most of the domestic market. In this context, many large foreign companies do not want to lose the large market of my country and have come to China to cooperate and build factories. In 2006, BASF, Huntsman and Shanghai Huaheng Group jointly established a new 240,000-ton MDI device and a 160,000-ton TDI device in Caojing, Shanghai and put them into operation. In 2008, Bayer (China) Company wholly-owned a new 350,000-ton MDI and 160,000-ton TDI plant in Caojing, Shanghai, and put it into operation, and is preparing to install a 20,000-ton HDI production unit. By 2008, my country's MDI production capacity reached 1.09 million tons, with an output of 503,000 tons. The consumption that year was 814,000 tons, and the self-sufficiency rate rose to more than 60%. TDI production capacity reached 390,000 tons, output was 220,000 tons, and consumption for the year was 394,000 tons. The self-sufficiency rate exceeded 55%, changing the passive situation of long-term dependence on imports. In addition, 850,000 tons of new production capacity will be built in the next five years. By then, my country's isocyanate production capacity will reach 2.34 million tons, which can basically meet domestic demand, and is expected to become the world's largest isocyanate producer and consumer.

In 2005, my country's polyurethane output was 2.267 million tons. Among them, 600,000 tons are soft foam, accounting for 26.5%. Hard foam accounted for 550,000 tons, accounting for 24.3%, and soft and hard foam accounted for 50.8%, which is lower than the global proportion. In addition, the CPU 60,000 tons, accounting for 2.65%. TPU 120,000 tons , accounting for 5.3%. Waterproofing and paving materials accounted for 100,000 tons, accounting for 4.42%. Spandex is 160,000 tons, accounting for 7.1%. The sole raw liquid is 200,000 tons, accounting for 8.84%. 195,000 tons of synthetic leather slurry (dry resin),accounts for8.62%. Coatings: 117,000 tons (dry resin), accounting for 5.2%. Adhesives and sealants accounted for 80,000 tons (dry resin), accounting for 3.54%.

Distribution of polyurethane product types in my country, foam accounts for about 50%, which is lower than the global average (about 60%), and industries closely related to people's lives, such as clothing, leather products, shoemaking, etc. The proportion of polyurethane consumed by the industry is much larger than that in developed countries. my country has a large population, is a country with a high concentration of labor-intensive industries, and is a major producer of daily necessities in the world. The huge demand will undoubtedly greatly promote the rapid growth of spandex, PU leather, sole solution, and PU adhesive for shoes in my country. In 2009, my country's spandex production capacity reached 340,000 tons, accounting for about 60% of the world's.