聚氨基甲酸酯（Polyurethane）

聚氨基甲酸酯（Polyurethane） 聚氨基甲酸酯(Polyurethane) Polyurethane Essential information Polyurethane polyurethane Pinyin: J N J Ji is connected. Su have a n zh from polyurethane for polyurethane, containing repeating carbamate groups in the main chain (NHCOO) largemolecularcompounds. It is made up of organic diisocyanate or polyisocyanate with two hydroxyl or polyhydroxy compounds. In addition to urethane, polyurethanes can also contain ethers, esters, urea, urea, two urea, and urethane groups. Polyurethane structure, English Name: Polyurethane R & D history Polyurethane (TPU) is a kind of polymer made of polyisocyanate and polyether polyol or polyester polyol or / or small molecule polyol, polyamine or water chain extender or cross linking agent. By changing the kind and composition of the raw materials, the morphology and properties of the products can be changed substantially, and the final products from softness to hardness can be obtained. Polyurethane products include soft, semi hard and hard foamed plastics, elastomers, paints, adhesives, sealants, coating synthetic leather, elastic fiber, are widely used in automobile manufacturing, refrigerator manufacturing, transportation, civil construction, footwear, leather, fabrics, machinery, petrochemical, mining machinery, aviation, medical, agriculture and many other areas. 1937 German Otto professor Bayer first discovered a polyisocyanate compound and a polyol for addition polymerization can be made of polyurethane, and on this basis into industrial application, Britain and other countries from 1945 to 1947 in Germany was the manufacturing technology of polyurethane resin industry started in 1950. Japan in 1955 from Germany Bayer company and the United States DuPont company introduced polyurethane industrial production technology. At the end of the 1950s, China's polyurethane industry began to develop, and developed rapidly in the past lO years. Preparation source A high degree polyurethane obtained by the action of two or more isocyanates with two or more hydroxyl compounds Daughter compound. Polyurethane is a polymer compound, containing - NHCOO - unit of the molecular structure, the unit is composed of isocyanate and hydroxyl reaction, the reaction equation as follows: - N=C=O + HO - to - NH-COO - polyurethane found: in 1930s, the German Otto Bayer firstly synthesized TPU. Around 1950, TPU emerged as a textile finishing agent in Europe, but mostly solvent based products for dry coating finishing. In 1960s, because of the enhancement of people's awareness of environmental protection and the introduction of government environmental laws and regulations, the TPU coating of water system came into being. Since 70s, PU coating has developed rapidly, and PU coated fabric has been widely used. Since 80s, there has been a breakthrough in the research and application of TPU. Compared with foreign countries, the research on PU finishing agent in China is late. Main use According to the raw materials used in different, there may be different properties of products, generally polyester and polyether two categories. It can be used in the manufacture of plastics, rubber, fibers, hard and soft foam plastics, adhesives and coatings, etc.. Production scale After more than 60 years of development, polyurethane has become an important variety of synthetic resin. The world polyurethane consumption was estimated at 7.7Mt in 1999, and the total output of polyurethane reached 8.5Mt in 2000. In recent years, the Asia Pacific region has become the world's fastest growing area of polyurethane industry, while China is the most promising country. It is estimated that in 1998 the total output of polyurethane products is about 770kt (after deducting solvent, about 555kt), in 2000 about 920kt, is expected to 2005 polyurethane material demand will reach 1.4 ~ 1.5Mt Production technology In 1940s, the German Bayer laboratory used diisocyanate and polyol carbamate As a raw material, polyurethane samples such as rigid foam plastics were prepared. The United States in 1946 launched a rigid polyurethane foam research, products used in aircraft sandwich plate parts. In 1952, Bayer reported on the pilot study of polyester flexible polyurethane foam; From 1952 to 1954, and the development method of continuous production of polyester type soft foam polyurethane, and developed the corresponding production equipment; in 1961, the vapor pressure of low PAPI polyisocyanate preparation of rigid polyurethane foam, improves the performance of hard products and reduced construction toxicity, and applied in the spraying process, the the scope of application of rigid foam to further expand. Because of the low production of polyether polyol in 60s, and the development of one-step and continuous soft foam process and equipment, polyurethane soft foam has been applied. In the mid 60s, cold curing, semi hard foam and self skinning foam were developed. In 70s, a cold cure high resilience foam was developed on the basis of high active polyether polyols. In 70s, Maxfoam flat top foaming process and vertical foaming process were developed to make polyurethane soft foam process mature. Later, with the development of a variety of new polyether polyols and foam agents, a variety of molded polyurethane foams were also developed. Product application Polyurethane foams are widely used at present. Soft foam is mainly used for furniture and transport all kinds of pad material, insulation materials; rigid foams are mainly used in household appliances, room wall insulation waterproof and thermal insulation pipeline, spray foam insulation materials, building board, refrigerated trucks and cold storage insulation material; semi hard foam in the direction of the car dashboard, disk etc.. Polyurethane on the market There are various specifications for the use of foam composite (two-component premix), mainly used for (cold curing), high resilience foam, semi rigid foam, casting and spraying of rigid foam, etc.. Polyurethane elastomer has higher elasticity and strength, better wear resistance, oil resistance, fatigue resistance and seismic resistance in a wide range of hardness. It has the name of "wear-resistant rubber". The polyurethane elastomer in polyurethane products production is small, but the polyurethane elastomer has excellent comprehensive properties, has been widely used in metallurgy, petroleum, automobile, mineral processing, water conservancy, textile, printing, medical, sports, food processing, construction and other industrial sectors. PU is a polyurethane, polyurethane leather is ingredients skin. Now this material is widely used clothing manufacturer production of clothing, leather clothing is commonly known as.PU English polyurethane. The chemical name Chinese polyurethane and its quality is good or bad, good use of imported PU leather bag; PU skin is generally the opposite is the second layer of leather leather on the surface, coated with PU resin, so also called paster cowhide. The price is lower and the utilization rate is high. It varies with the change of the process also made various grades of varieties, such as imported two layers of leather, with unique technology, stable quality, new varieties and other characteristics, for the present high-grade leather, the price and the class as head of leather. PU leather and leather PU bag with different characteristics, beautiful appearance, good care, the price is low, but do not wear leather, easy to break; the price is expensive, do trouble, but durable. Edit this paragraph polyurethane coating agent Polyurethane coating agent is the main type of development today, its advantages: soft and elastic coating; coating strength, can be used in a very thin coating; coating porous, having moisture and ventilation properties; wear resistance, moisture resistance, resistance to dry cleaning. The disadvantages are: Polyurethane carbamate; High resistance to climate; water, heat and alkali to hydrolysis. TPU coating agents are classified according to their composition: polyester polyurethane, polyether polyurethane, aromatic isocyanate based polyurethane, aliphatic isocyanate based polyurethane. According to the medium used, it is divided into solvent and water system. Polymers with repeating structural units containing NHCOO - groups on the macromolecular backbone are collectively referred to as polyurethanes, referred to as polyurethanes (PU). It is prepared by the reaction of organic polyisocyanate with polyether or polyester polyols. The common polyurethane plastics appear in the form of soft and hard foam. Rigid polyether plastics (Rigid, Polyether, Polyurethane, Foams) physical and chemical properties density: 0.04 ~ 0. 06g/cm3, tensile strength: 0.147MPa, bending strength: 0.196MPa, thermal conductivity: 0.035W/ (m.K). The products are characterized by: according to the specific use requirements, by changing the specifications of raw materials, varieties and formulations, the synthesis of the required properties of the product. The product is light (density adjustable), high strength, insulation and sound insulation performance, good electrical properties, good processing, chemical resistance, low water absorption, adding flame retardant, self extinguishing products can be prepared. Mainly used for cold storage, cold cans, pipes and other departments for insulation, insulation, cold protection materials, high-rise buildings, aviation, automobile and other departments to do structural materials, insulation, sound insulation and light weight role. Ultra low density hard foam can be used as shockproof packing material and filling material for hull sandwich. Rigid polyester plastics (Rigid, Polyester, Polyurethane, Foams) physical and chemical properties density: 0.0368g/cm3, tensile strength: 0.414MPa, compressive strength (10% deformation): 0.323MPa, thermal conductivity: 0.035W/ (m.K). Compared with the hard foam of the same density, polyether has higher tensile strength, better oil resistance, solvent resistance and oxidation resistance, but it has high viscosity and difficult operation. The main application field is similar to rigid polyether polyurethane foam. When the product has higher strength and temperature resistance, it is more suitable to use polyester foam. Such as sandwich materials for radar radome, three layers of structural material on aircraft, ship, insulation materials for electrical appliances, instruments and equipment, and shockproof packaging materials. Flexible Polyether Polyurethane Foams (Flexible, Polyether, Polyurethane, Foams) physical and chemical properties density: 0.03 ~ 0.07g/cm3, tensile strength: 8.83 ~ 117kPa, elongation (%): 150~300. Bending strength: 0.196MPa, thermal conductivity: 0.034 ~ 0.041W/ (m.K). Melting point (DEG C): 170~190. The main use of different density of flexible foam, the main use of some differences. Soft polyurethane foam (Flexible Polyester Polyurethane Foams) is mainly used for clothing, shoes lining, shoulder pads and precision instruments, shockproof packaging etc.. Edit this segment of the industry Throughout the world, the western developed countries polyurethane industry has already entered the mature stage of development, into the innovative research and development stage; the Asian market is growing rapidly, many multinational chemical companies have business focus and R & D center have moved to Asia and even China market; polyurethane market development in the Middle East region is still at the initial stage. Generally speaking, due to the rapid development of the national economy over the past ten years, China's polyurethane industry, including from basic raw materials to products and mechanical equipment, has been of considerable size. In 2005, China produced about 3 million tons of polyurethane, with an output value of about 60 billion yuan, an increase of 146% and 200% respectively over the 1 million 220 thousand tons in 2001 and about 20 billion yuan, with an average annual output growth rate of 25%, with an average annual output growth rate of more than 30%. In 2005, China consumed 510 thousand tons of MDI, 360 thousand tons of TDI and 889 thousand tons of polyether polyols. With the extensive application of polyurethane, the demand for raw materials has also increased substantially. At present, there are many foreign companies involved in polyurethane industry, such as Yantai Wanhua, Shanghai Huayi, Takahashi petrochemical, Shanghai chlor alkali chemical industry, chemistry, North Shanghai Lejoin Group occupies a space for one person and own, foreign companies including BASF, Bayer, Pu Huntsman, Dow Chemical, GE, imperial Asia, and other well-known companies have Degussa a certain market, Chinese market temptation more attracted Malaysia, India, Japan, South Korea and other countries of the customers and vendors. In the past ten years, although China's annual growth rate of polyurethane is two times of GDP, but China's per capita consumption of polyurethane has not reached the world average. In 2004, China's per capita MDI consumption was 0.35 kg, while the world average was 0.51 kg. According to per capita GDP development and polyurethane growth rate, China's polyurethane industry is still in a period of rapid growth. In the future, the development of China's polyurethane industry will be mainly driven by five major factors, that is, the total population, automobile industry, building energy efficiency, environmental protection requirements, and the leisure industry. During the period of 11th Five-Year, China's PU product consumption will maintain an average annual growth rate of 15%, when China will be the world's largest PU product manufacturing and consumption center. Edit the construction process of this section Scope of application All kinds of waterproof roof with protective layer, toilet, underground building waterproof project, etc.. Construction preparation 1. main materials: group A (prepolymer) B (solid) 2. construction tools: use name name use An electric blender to mix a and B material with a paint brush bottom glue A stirring barrel mixing a and B material for rolling brush bottom glue Small paint mixture with a small float bottled with primary repair Plastic scraper scraping oil mixture for the basic cleaning blade industry The small tin scraper scraping parts in complex mixtures with clean mop base Rubber scraper scraping mixture with 50kg for batching scales Technological process Surface treatment of base surface coating polyurethane bottom coating - local strengthening coating polyurethane coating one or two, three times surface protection or modification Grassroots requirements and handling The 1. layer should be according to the design requirements for 1 to 3 of the cement mortar with 1/50 flashing slope, the surface should be smooth light pressure, rugged, loose sand and dust and other defects are not allowed. Drain or floor drain should be lower than the entire waterproof layer, in order to remove stagnant water. The pipe position with casing shall be above 20mm above the base surface. The angle of yin and Yang should be made into a small radius of 10mm, so that the paint can be constructed. 2. all fittings, sanitary equipment, floor drain or drain must be firmly installed, tight seams, smooth head, no loose phenomenon. 3. during construction, the traditional polyurethane waterproof coating construction, waterproof base should be basically in dry condition, the water content of less than 9% is appropriate, it is a simple method to determine the rubber plate area of 1 square meters, the thickness is 1.5 ~ 2.0mm coverage at the grassroots level, place 2 to 3 hours, such as covering the surface of the base layer without watermark one side of the base plate, the rubber condensation watermark close, according to experience shows that the water content is less than 9%, to meet the construction requirements. The 911 type polyurethane coating Xi'an Yuzhongqing waterproof material limited liability company production without this requirement, as long as the basic construction can be no water. 4. before construction, first to shovel and a broom to bumps on the surface of the base, such as mortar bumps and dust debris to completely clean. On the corner, pipe root, floor drain and drainage should be carefully cleaning Mizoguchi and other parts, if there is oil, rust, use wire brush, sandpaper and organic solvent to be thoroughly cleaned. Construction requirements 1. bottom glue coating: this process is equivalent to the traditional asphalt waterproofing coating cold base oil, its purpose is to prevent the partition base moisture, waterproof coating drum off; strengthening grassroots, to improve the bonding strength of coating and base coating, prevent pin holes and other defects. Our company recommends using polyurethane base rubber as the base treatment. Preparation of polyurethane base adhesive: the proportion of 1:2 and 3 (weight ratio) of polyurethane nail material and B material (other coating according to product specification) shall be matched. When the material is thicker, it can be diluted with a special diluent. It should not be diluted with acid or oily diluent, so as not to affect the quality of the original product. In preparation, it should be the first dilution B material stirring 2-3 minutes, such as without dilution, can be used directly in a and B group distribution and stirring for 5-10 minutes, a lift, visible to the uniform liquid from the container and slowly slide better, we should know that the material should be immediately open the cover tightly, so as to avoid freezing scrapped, should be based on the mixture the actual amount of use immediately. (Note: 991 type construction should be a mixed material into B material to stir, and type 911, type 851 in 2.): local enhancement of the expansion joints, control joints, corner, pipeline joint, which is composed of a layer of reinforced fabric reinforced, After curing, the whole waterproof construction is carried out. Article 3.: Construction of the bottom glue coating over the basic dry after curing, plastic or rubber scraper scraping evenly coated with a layer of paint, coating for uniform, not too thick or too thin coating thickness is about 0.8mm. When it starts to be scraped, the construction escape route and the scraping sequence shall be considered in accordance with the size, shape and material of the construction area. 4., second times coating construction: after the first coating is basically solidified, then scrape second times coating on its surface, and the coating method is the same as the first coating. In order to ensure the quality of waterproof works, the direction of the scraping must be perpendicular to the direction of the first coating. The interval of re coating time shall be determined by the temperature at construction and the degree of coating cure (by hand touching non stick). 5., after second times the film curing, and then according to the above method coated third times coating. 6. paving protective layer or facing material in the third film after the completion of construction is not completely cured, but on the surface of thin and small clean sand (diameter less than 2mm), between the cement mortar will cover the increase of coating layer and adhesive ability. When the film has been cured and checked and accepted, cement mortar, protective layer or paste tile, mosaic and so on can be applied. The construction process of 7. two cloth three coated: this process by the current market are not many operation methods of the process is: according to the above description of the processing base is the same, after the end of the first brush again, the glass screen cloth evenly attached to the top, rely on polyurethane adhesive stick it the first time after drying, according to the same method for second times, all to be dried, finally according to the above requirements brushing again polyurethane waterproof coating. Bathroom, kitchen and roof construction methods are consistent. It is important to note that the glass screen mesh is required to be flat when it is laid and the space in the bathroom is relatively small. Other requirements are consistent with the traditional construction process requirements of polyurethane. Matters needing attention 1., when the paint viscosity is too large, it is difficult to scrape coating construction, you can add a small amount of special diluent diluted, to reduce viscosity, adding quantity shall not be greater than 10% of the material. Note: if the user needs to dilute the polyurethane, we must use our company's diluent. We are not responsible for the quality problems arising from the purchase of other thinners such as xylene or gasoline. 2., air hole, bubble: material mixing method and mixing time did not make material mixing evenly; construction should use power, speed is not too high mixer. Another reason is the base is not clean, do the film should be careful before cleaning the substrate, no floating sand and dust, the base should not appear the stomatal pore, layer of coating film should be treated according to the requirement of process, prevent the damage caused by the leakage of coating. 3. drum: base sand, peeling, cracking, drying, coating the poor bond; base construction should be careful operation and maintenance, to the grassroots after drying, first coated with coating after curing, and then according to the construction technique of waterproof layer by layer coating. 4., film edge: Waterproof edge, sub brush overlap, with the emergence of peeling off the base. The main reason is that the base is not clean or dry, the operation is not careful, the seal is not good, the bottom coating adhesive force is not strong and so on. Therefore, the grassroots should ensure clean and dry, careful operation. 5., damage: coating waterproof layer, layered construction process or all the coating construction, without curing coating on the operation, or put tools, materials, etc., will be coated bad. Scratched. The integrity of the coating shall be protected during construction. 6., construction should pay attention to fire prevention, construction personnel should take protective measures, the construction site requires good ventilation, in order to prevent solvent poisoning. 7. found the quantity precipitation phenomenon, should mix before use, so as not to affect the quality of 8. A and B of two kinds of materials are flammable, toxic, drum, storage should be sealed, placed in a cool, dry, no strong direct sunlight ground. 9. construction temperature should be above 5 degrees celsius. Edit this paragraph as a shark skin swimsuit The shark skin swimsuit is a nickname for its appearance. Its core technique is to mimic shark skin. Biologists have discovered that rough V - shaped folds on shark skin can greatly reduce the friction of water flow, allowing the flow of water around the body to flow more efficiently, allowing sharks to swim quickly. The skin's ultra stretched fiber surface is made entirely of shark skin surfaces. In addition, this swimsuit also fully integrates the bionics principle: imitates human's tendon in the joint, provides the impetus for the athlete back stroke, imitates the human skin in the cloth, is full of elasticity. Experiments have shown that shark's skin fiber can reduce the resistance of 3% water, which in 1% seconds to determine the outcome of the swimming competition has extraordinary significance. Root cause: "shark skin" uses a polyurethane fiber that increases buoyancy. Edit this paragraph of related news The Ministry of public security officials in Shanghai: fire insulation materials after deadly poison in November 17, 2010 according to a survey, the survey group said the illegal use of a lot of polyurethane foam and other flammable materials, is an important cause of Shanghai teachers, the rapid spread of the big fire. This material once the combustion will produce highly toxic hydrogen cyanide gas, inhaled a mouth will die. In 2008, Shenzhen Dance Club fire, Ji'nan Olympic Sports Center Gym two inferior, and external wall insulation materials. Zhu Liping, deputy director of the Fire Department of the Ministry of public security, called on the relevant departments to formulate regulations as soon as possible so as to prevent the use of polyurethane for exterior wall insulation and interior decoration. Quickly generate toxic gas burning Shanghai fire building materials (2) as of November 17th, Shanghai "11 - 15" particularly serious fire accident has killed 53 people, 70 people are still being treated in hospital. How has this rare fire happened in recent years? Why does it cause such heavy casualties? How has the whole fire rescue work gone through? What lessons should we draw from behind the tragedy? A careful survey of the building on fire, found that there are many factors causing disaster: the building is a building around take the full scaffolding will be completely surrounded the whole building; two is also wrapped outside is three nylon netting; the scaffold is made of bamboo pedal; four is a building facade a large number of polyurethane foam insulation materials. The nylon netting and bamboo sheet, polyurethane foam are flammable, especially polyurethane foam, once the burning will produce highly toxic hydrogen cyanide gas, if inhalation poisoning. It is worth noting that the polyurethane foam burning very fast, how fast can it go? Longgang District of Shenzhen city in 2008 Wang dance club "9 - 20" fire, due to the extensive use of polyurethane materials, decoration, performers use props guns ignited the roof of polyurethane materials, surveillance video shows the scene, the fire after only 46 seconds, toxic smoke enveloped the entire hall, killing 44 people. The Shanghai "11 - 15" fire, fire brigade immediately dispatched after the alarm within a minute, the first time arrived at the scene, they found that the entire building has long been surrounded by smoke, fire along the floor straight jump up, and it was windy, accelerated the spread of fire, instantly form a large, three-dimensional the fire. [1] Steps of particle size analysis 1. determine the boundaries of the particle process and determine each of the problems in different industrial processes, requiring knowledge and practice of particle technology. 2. to determine the particle size range of information and type boundaries according to particle size measurement requirements and different applications, each kind of technology provides only certain aspects of the information granularity and limited selection of equipment, so the granularity information analysts must guarantee that the resulting is needed in the practical application, the measurement and related parameters, not will work related parameter measurement. 3. according to the need to select the most appropriate analysis principle mentioned above, using different methods to measure the same particle size value, income is different, so choose the particle properties in the process of the closest in practical application, Also check the relevant material testing standards to the method to ensure that the analysis method is correct. 4., according to the principle of analysis, select analytical instruments, according to the types of instruments available on the market, measuring the amount of samples, measuring time, measuring the same with the operation and other factors, select the appropriate analytical instruments. 5. obtain representative samples, which are usually divided into four forms: production samples, rental samples, laboratory samples and measurement samples.