chloroprene rubber price

Chloroprene rubber (CR)  is one of the commonly used rubber varieties. The strength of vulcanized rubber without carbon black reinforcement can reach 28MPa, and the relative elongation is about 800%. It has the characteristics of oil resistance, flame resistance, oxidation resistance and ozone resistance. It is soluble in benzene and chloroform. It swells slightly but does not dissolve in mineral oil and vegetable oil. 1. Progress in CR Technology Abroad Monomer Production DuPont in the U.S. came up with a liquid method to make chloroprene from butadiene. This is safer than the gas method that was first used. It can produce higher yield products at a lower cost, improve safety, and reduce maintenance costs. In 1992, the company upgraded its monomer production line, moving from a single-loop control system to a computerized distributed control system.  Post-processing technology Recent progress in CR post-processing tech is apparent in the developments related to spiral extrusion dehydration and drying. Chloroprene latex and coagulant go into a screw extruder that has a specific design. The coagulated latex removes most of the water in the dehydration section of the extruder by the back pressure. The success of this process has created conditions for the industrial production of CR and asphalt and CR and short fibers, thereby increasing the operational flexibility and being able to handle CR varieties with poor freezing film-forming and tape-forming properties. In 1992, DuPont launched a series of elastomer masterbatches including CR with Kevlar (polyarylamide) short fibers as reinforcement materials, proving that this process has begun to be used in the production of blended products. Development of new varieties There are hundreds of foreign brands. Companies in the United States and Japan have developed many high-performance special CR based on a series of mature brands. In order to improve the thermal stability of CR, Bayer has developed copolymers of chloroprene (CD) with carboxylic acid amide, carboxylic acid anhydride and (or) carboxylic acid monomers. These new CR also have better spraying and brushing characteristics. Denka Corporation of Japan has also improved traditional products and launched a new generation of CR (Denka chloroprene rubber). For example, the DCR 20 series. Tosoh Corporation of Japan is also developing special shock-absorbing CR, and has produced CR latexes with high softening temperature, good normal temperature and high temperature adhesive properties, high water resistance and stability (SKYPRENE Chloroprene Rubber).     2. Progress in domestic CR technology In 1958, Changshou Chemical Plant in Sichuan, my country built a device for producing CR by acetylene. The main CR production in China does not control the conversion rate, and many places use manual operations, which is basically a workshop-style production status. Besides the earlier producers of CR glue like Chongqing Changshou Chemical Co., Ltd., Shanxi Synthetic Rubber Company, Jiangsu Lianshui Chemical General Plant, and Tianjin Donghai Adhesives Company, Shandong Laizhou Kangbaili Glue Industry Co., Ltd. developed in October 2003 a new CR glue. They carefully chose and mixed the composite solvent.    3. Suggestions for the development of domestic CR industry Strengthen technology development For domestic carbon black firms, boosting investment in science and tech, along with adopting and assimilating advanced foreign tech, is key. These actions should lower consumption and costs, and it should raise acetylene use from 57% to over 70% quickly. Strengthen the development of new varieties To maintain the Mooney viscosity in current products, we will create new types. The focus will be on making functional latex, like carboxyl and copolymer latex. Our goal is to bring high Mooney, non-sulfur regulated WHV to industrial production. Increase market share In the next few years, the market of CR in my country will be saturated, and relevant manufacturers can consider developing overseas markets. At present, the development trend of CR in the world is that the European and American markets are shrinking, while China, Eastern Europe, Russia and Southeast Asia are in the rising stage. CR can not only contend with imported goods locally, but can also progressively expand sales to North America, Eastern Europe, Russia, East Asia, and Southeast Asia.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com  

Chloroprene adhesive is popular in the shoemaking industry because it bonds materials very well. Among them, grafted chloroprene adhesive is the most widely used. As shoe materials develop towards lighter colors, the color requirements for adhesives are becoming more and more stringent. Right now, SN24 adhesive starts out light, but it yellows pretty fast after sitting around for a while, especially if it's in the sun. After being prepared into chloroprene adhesive, there is a yellowing problem, which leads to two problems: first, it affects the appearance of shoes. For light-colored shoes such as sports shoes and travel shoes, the problem is more prominent; second, the darkening of color is a manifestation of polymer aging, which leads to the deterioration of the bonding performance of the adhesive. Therefore, in order to improve the appearance of footwear and ensure that it does not turn yellow during wearing, a yellowing-resistant adhesive should be used.   1. Experimental materials Chloroprene rubber latex: Chloroprene Rubber SN-242, Sana Synthetic Rubber Co., Ltd.; toluene, methyl methacrylate, butanone, BPO, SKYPRENE G-40S; Denka A90 Chloroprene rubber   2. Performance test results 2.1 Comparison of glue solutions The different types of dry glue obtained by the drum were dissolved in toluene to obtain the glue solution comparison chart in Figure 1, and the comparison chart of different types of glue solutions after heating is shown in Figure 2.   As can be seen from Figure 1, the color of the glue solution in this experiment is not much different from the color of the same type of glue solution at home and abroad. After adding BPO and MMA and shaking well, the color will change.After being tested, SN242A became yellow. Domestic rubber samples No. 2 and No. 3 also turned yellow. The other samples got a bit darker, but our test rubber was still lighter than domestic rubber No. 4. Its color was close to that of samples No. 7 and No. 8.After 20 minutes in a 90℃ oven, rubber samples No. 1, 2, 3, and 5 turned yellow. Samples No. 4, 6, 7, and 8 got lighter. After an hour, the colors changed in the same way, but everything was darker than it was at 20 minutes.As you can see in Figures 1 and 2, when this test rubber was dissolved in toluene and heated with an initiator, it looked a little whiter than similar domestic glues. It looked about the same as similar foreign glues.   2.2 Grafting comparison According to the grafting formula, 0.1 parts of BPO and 50 parts of methyl methacrylate were added, and different types of chloroprene rubber were grafted. The viscosity of the solution before and after grafting was measured, as shown in Table 4. The comparison between the experimental glue and the domestic glue after grafting is shown in Figure 3.     Figure 3 presents a comparison between our experimental glue and a domestic glue following grafting.When exposed to free radicals, the unsaturated double bonds on the chloroprene rubber backbone transform the MMA monomer into a monomer free radical. This then grafts and copolymerizes with CR through a chain transfer reaction, creating a complex graft copolymer. This process leads to asymmetry and polarity in the adhesive structure, improving adhesion.   Based on the data in Table 5, our experimental glue shows a high grafting rate, nearly 100%. This solves the issue of low grafting rates seen with SN242, which stem from residual terminators. Plus, it eliminates the problem of red glue forming during the grafting process. Figure 3 is a comparison chart of the grafted glue solution after being placed in the sun for several days. The color of the experimental glue solution is much lighter than that of SN242.   2.3 GPC comparison According to Figure 4 and Table 5, the relative molecular weight and relative molecular weight distribution of the experimental glue are not much different from those of foreign glue. The average relative molecular weight is around 350,000, and the relative molecular weight distribution is below 2.3, which is larger than the relative molecular weight of domestic grafted glue, and the relative molecular weight distribution is narrow, and the regularity of the molecular chain is higher.     2.4 DSC comparison Based on the data in Figure 5 and Table 5, the experimental glue's glass transition temperature is similar to both domestic and foreign glues. The experimental glue's crystallization temperature, which is higher than the domestic glue, is nearly the same as the foreign glue.       3 Conclusion The chloroprene rubber adhesive developed in this paper has excellent yellowing resistance and stable grafting performance. Through DSC and GPC analysis, grafted chloroprene rubber with uniform relative molecular weight and high regularity was obtained, and its performance is comparable to that of the same type of foreign rubber.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Chloroprene rubber (CR) is an important variety of synthetic rubber. It stands up well to light, aging, flexing, acids, bases, ozone, flames, heat, and oil. It also has good physical and electrical properties. Its comprehensive performance is unmatched by natural rubber and other synthetic rubbers. It is widely used in defense, transportation, construction, light industry and military industry. Chloroprene rubber has several uses. It's a key element in making auto parts, machinery, industrial items, and adhesives. You'll also find it in construction materials, coated fabrics, and wire and cable insulation. By itself, chloroprene rubber is used to create rubber harness clips and shock absorbers for cars and farm equipment. Initially, chloroprene rubber from Japan's DENKA and Japan's Toyo Soda was used. Later, due to the increase in raw material prices and the restrictions of the procurement cycle, a series of research and development work on the replacement of imported chloroprene rubber with domestic chloroprene rubber was carried out. Finally, the replacement goal was successfully achieved, and some process and formula problems of domestic chloroprene rubber in the use process were solved.   1. Neoprene rubber model Imported neoprene rubber model: Denka M120 Chloroprene Rubber, a product of Japan DENKA, light-colored blocks; B-10, a product of Japan Toyo Soda, light-colored blocks. Domestic neoprene rubber model: CR3221, a product of Chongqing Changshou Chemical Co., Ltd. Polychloroprene Rubber CR3221 is a chloroprene polymer with sulfur and diisopropyl xanthate disulfide as mixed regulators, with a low crystallization rate, a relative density of 1.23, beige or brown blocks, and a non-polluting type.   2. Production process performance comparison Imported neoprene handles better during production. For example, the raw rubber pieces do not stick together, even after baking, which makes them easy to measure. The process is smooth; it does not stick to the roller, so removing it is simple. The semi-finished film is stiff and holds its shape well. Domestic neoprene does not perform as well. The rubber pieces tend to stick, especially after baking. The rubber also sticks to the roller, which makes removal hard, and the semi-finished film sticks easily and loses its shape. Despite these things, domestic neoprene has some benefits. It mixes powder faster and with less effort in both internal and open mixers. Rubber from Japan is harder to mix. In the open mixer, M-120 can even fall off the roller at first. The internal mixer requires more effort and time, especially in the winter. Domestic mixed rubber still works well after being stored for a long time. Rubber from Japan, especially M-120, gets hard and loses its flexibility after two to four weeks. Tests show that production methods that work for imported neoprene do not work well for domestic neoprene. The original method needs some changes. If not, it will be hard to make it work for production, even when the physical and mechanical qualities meet the standards.   3.  Conclusion Compared with Japanese chloroprene rubber, domestic chloroprene rubber CR3221 has lower Mooney viscosity and greater viscosity, which is more favorable for mixing and powder consumption, and can significantly reduce the operation time, but the processability is poor and the operation is difficult. If the temperature is not well controlled, the operation is improper or the rubber is over-mixed, it may cause the roller to stick or even fail to unload normally. By selecting the correct process conditions and methods and adjusting the formula appropriately, it can fully meet the production needs.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Chloroprene rubber (CR), a synthetic material, is a common choice for making timing belts because of its good physical and chemical traits. Neoprene timing belts resist aging well and work best in regular transmission systems, but some situations might need different materials. 1. Aging resistance of chloroprene rubber timing belts Neoprene resists oxidation well, helping timing belts stay flexible and strong during regular use. This prevents the material from getting fragile or breaking down due to oxidation, making it good for machines exposed to air for extended periods, as it reduces the possibility of cracks or surface hardening. Heat resistance: The operating temperature range is generally between -20°C and 100°C, and it can operate for a long time in a medium-high temperature environment; under high temperature conditions, although its performance will decrease slightly, the aging process can be delayed by adding heat-resistant agents. Anti-ultraviolet performance: Neoprene has moderate anti-ultraviolet ability, but the surface may oxidize under long-term exposure to strong light, resulting in color changes and the formation of tiny cracks. Moisture resistance: Neoprene has good resistance to moisture and is suitable for high humidity environments. It is not easy to deteriorate due to moisture intrusion. Chemical corrosion resistance(Chloroprene Rubber SN-236T): It has good corrosion resistance to grease, weak acid, alkali and some chemical solvents, which slows down the aging rate, but is not suitable for contact with strong oxidizing chemicals.   2. Applicable scenarios of chloroprene rubber timing belts Industrial transmission equipment(Chloroprene Rubber SN-244X): Applicable to power transmission of conventional mechanical equipment, such as textile machinery, packaging equipment and general processing equipment. Medium temperature environment: It performs well in medium and high temperature (below 100°C) application scenarios, such as industrial drying equipment or HVAC systems. Indoor environment: Equipment with low requirements for UV resistance, such as indoor automation equipment or low maintenance systems. Medium humidity and chemical environment: It can be applied to equipment that contacts oils and weak acid and alkali environments, such as food processing machinery and light chemical equipment.   3. Limitations of aging resistance of chloroprene rubber timing belt Prolonged exposure to temperatures above 100°C can speed up the aging process, leading to reduced flexibility or hardening of the timing belt. When working in such conditions, fluororubber or silicone rubber belts are the preferred choice. Extended exposure to strong sunlight can cause surface oxidation and cracking, which reduces the lifespan of the belt. Polyurethane belts or those with anti-UV coatings are advisable for outdoor setups. Strong acids, bases, or concentrated chemical solvents can cause corrosion if the material isn't resistant enough.   4. Methods to extend the aging resistance of chloroprene rubber timing belts Reasonable storage: Store in a dry, ventilated, light-proof environment to avoid ultraviolet radiation and high temperature. Regular inspection: Regularly check whether there are cracks or hardening on the surface of the timing belt during use, and remove oil and chemical residues in time. Adding antioxidants: By adding antioxidants or anti-ultraviolet ingredients during the manufacturing process, the aging resistance of the timing belt can be significantly improved. Optimize working conditions: Avoid running the synchronous belt under excessive tension or extreme temperature to reduce the risk of aging.   Chloroprene rubber synchronous belts resist oxidation, heat, and moisture well, so they age slowly and work for many standard jobs. Still, they might not work as well when it's very hot, there's a lot of ultraviolet light, or things are very corrosive. You can make these belts last longer by storing and using them properly and keeping up with regular maintenance. Because of this, they're a solid, affordable choice.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com  

1. Research and development of chloroprene rubber Chloroprene rubber & Neoprene latex is famous for its weather resistance, excellent physical properties, chemical resistance and oil resistance. Therefore, chloroprene rubber is widely used in rubber accessories that are exposed to the air and require oil resistance and high mechanical properties, such as: hoses, conveyor belts, transmission belts, cable sheaths, dust covers, shock pads, air capsules and other rubber products that require weather resistance, oil resistance, high physical properties and good flexural properties. The trade name of LANXESS chloroprene rubber is Baypren, which is translated into Bayer Ping in Chinese. It evolved from the original Perbunan C of Bayer Company and was produced in the Dormagen factory in Germany. 2. Trade names and naming principles of LANXESS chloroprene rubber Trade names of LANXESS chloroprene rubber LANXESS chloroprene rubber has a variety of brands to meet the needs of different products and different application environments. For specific brands, please refer to the LANXESS rubber product brand table. The main varieties of Lanxess nylon-butadiene rubber currently sold in China are: Baypren126 is a molded grade, which is resistant to high and low temperatures, has good physical and mechanical properties, excellent process, and does not burn or stick to rollers. Baypren 116 has a lower Mooney viscosity than Bapren126, and the rubber compound has good fluidity. It is a grade for extruded products, with stable extruded dimensions, smooth surface, and high efficiency. Baypren711 is a vulcanization-adjustable grade, used for adhesive tapes. It has a high sulfur content, good processability of the rubber compound, good adhesion to reinforcing materials, and is wear-resistant. Baypren 210 is a universal brand. It has excellent comprehensive performance and meets the processing requirements of different processes and products. The price is relatively low. Baypren 230 (SN-238) is an extra-high Mooney grade with high mechanical strength. It is suitable for high strength and blending with other grades to achieve special product performance and process requirements. Baypren 114 is a pre-crosslinked grade. It is suitable for extruding high-performance thin-walled and precise-size products, and the extruded products are resistant to collapse. Such as continuous vulcanization production of automotive wiper strips and other products and processes. Naming principles of LANXESS chloroprene rubber LANXESS chloroprene rubber consists of a product name plus a 3-digit number. The product name is: Baypren, which is translated as Bayer Ping. The brand name is represented by a 3-digit number, and Baypren 126 is used as an example as follows: The first digit indicates the crystallization tendency, 1 slight/2 medium/3 strong crystallization (general brand); sulfur content, 5 low sulfur/6 medium/7 high sulfur (sulfur-adjusted brand). The second digit indicates the Mooney viscosity: 1 low Mooney/2 medium/3 high Mooney. The third digit indicates special properties: 4 pre-crosslinking; 5 pre-crosslinking plus xanthogenic acid disulfide adjustment; 6 xanthogenic acid disulfide adjustment. The third digits 1 and 2 indicate the Mooney viscosity of the raw rubber and the tendency to form products. For example, the crystallinity of Baypren 111 is extremely low, while the crystallinity of Baypren 112 is low to moderate.   3. Future Development 1)The high-tech development of automobile products and the strengthening of safety, hygiene and environmental protection concepts have caused fundamental changes in rubber materials. Many general-purpose products will inevitably be replaced by special brands to adapt to their special properties.  2) Modern rubber equipment is becoming more and more advanced and efficient, forcing the manufacturing process to be more and more perfect. Many product processes have consciously or unconsciously shifted from the original molding method to the injection method. This has led to an increase in demand for rubber compounds with good performance, long scorch time, and non-stick rollers. More attention is paid to injection rubber compounds with good fluidity. Lanxess's special Mooney rubber compound (Mooney can reach as low as 28 Mooney) chloroprene rubber brand was developed for this purpose. 3) The development of high-precision and cutting-edge technology requires many products with extremely high physical properties and low temperature resistance. In this regard, LANXESS already has a variety of special-functional chloroprene rubber grades available for selection, which need to be developed and utilized in combination with their functional requirements during product design and development, and explore newer and more scientific uses.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Gloves are the most commonly used protective tools in the laboratory besides goggles. There are many types of gloves, and different gloves have different uses.     1. Natural rubber (latex) Latex gloves, made from natural rubber, typically lack a lining and are available in both clean and sterile versions. These gloves can provide effective protection against alkalis, alcohols, and a variety of chemical dilution aqueous solutions, and can better prevent corrosion from aldehydes and ketones.   2. Polyvinyl chloride (PVC) gloves The gloves do not contain allergens, are powder-free, have low dust generation, low ion content, strong chemical corrosion resistance, can protect almost all chemical hazardous substances, and also have anti-static properties. Thickened and treated surfaces (such as fleece surfaces) can also prevent general mechanical wear, and thickened types can also prevent cold, with an operating temperature of -4℃ to 66℃. Can be used in a dust-free environment. PVC gloves grading standards: Grade A products, no holes on the surface of the gloves (PVC gloves with powder), uniform powder, no obvious powder, transparent milky white color, no obvious ink spots, no impurities, and the size and physical properties of each part meet customer requirements. Grade B products, slight stains, 3 small black spots (1mm≤diameter≤2mm), or a large number of small black spots (diameter≤1mm) (diameter>5), deformation, impurities (diameter≤1mm), slightly yellow color, serious nail marks, cracks, and the size and physical properties of each part do not meet the requirements.   3. PE gloves PE gloves are disposable gloves made of polyethylene. These gloves are waterproof, oil-proof, anti-bacterial, and resistant to acids and bases. Note: PE gloves are safe to use with food and are non-toxic. It is better to keep PVC gloves away from food, especially if it's hot.     4. Nitrile rubber gloves Nitrile rubber gloves are usually divided into disposable gloves, medium-duty unlined gloves and light-duty lined gloves. These gloves can prevent erosion by grease (including animal fat), xylene, polyethylene and aliphatic solvents; they can also prevent most pesticide formulations and are often used in the use of biological components and other chemicals. Nitrile rubber gloves do not contain protein, amino compounds and other harmful substances, and rarely cause allergies. They are silicone-free and have certain antistatic properties, which are suitable for the production needs of the electronics industry. They have low surface chemical residues, low ion content and small particle content, and are suitable for strict clean room environments.   5. Neoprene gloves Similar to the comfort of natural rubber, neoprene gloves are resistant to light, aging, flexing, acid and alkali, ozone, combustion, heat and oil.   6. Butyl rubber gloves Butyl rubber is only used as a material for medium-sized unlined gloves and can be used for operations in glove boxes, anaerobic boxes, incubators, and operating boxes; it has super durability against fluoric acid, aqua regia, nitric acid, strong acids, strong alkalis, toluene, alcohol, etc., and is a special rubber synthetic resistant liquid gloves.   7. Polyvinyl alcohol (PVA) gloves Polyvinyl alcohol (PVA) can be used as a material for medium-sized lined gloves, so this type of gloves can provide a high level of protection and corrosion resistance against a variety of organic chemicals, such as aliphatic, aromatic hydrocarbons, chlorinated solvents, fluorocarbons and most ketones (except acetone), esters and ethers.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

CR modified materials are really popular these days.  A company called Shanghai Shuangpu Rubber Anti-Corrosion Lining Co., Ltd. has rolled out a bunch of different rubber linings, like CR, CR/NR, and NBR/CR. These products are proving to be quite useful across various sectors, including chemicals, electricity, steel, mining, and water treatment. You can see more about this in Figure 1.   Interestingly, Shanghai Shuangpu Rubber Anti-Corrosion Lining Co., Ltd. has done some side-by-side tests and discovered that certain fluoroprene rubbers made locally are performing on par with similar CR products that come from Japan and Germany. This is great news for the local industry, as it shows that we’re capable of producing high-quality materials that can stand shoulder to shoulder with the best from around the world. So, whether it’s keeping things from rusting or just making tough parts for machines, these rubber linings are definitely pulling their weight in various industries.   However, there are still few varieties of domestically produced fluoroprene rubbers, and there is no low-hardness fluoroprene rubber material. The existing main varieties, such as Chloroprene Rubber CR121, Chloroprene Rubber CR232, etc., are made of fluoroprene lining rubber sheets that are relatively hard, and the pre-vulcanized rubber sheets produced are very hard, making the pasting construction difficult. Further tests show that adding a large amount of softener to the formula can reduce the hardness, but when it reaches a certain amount, it will significantly affect the bonding strength. The production test also shows that the bonding strength of the cold-adhesive adhesive produced by domestic Chloroprene Rubber CR244 is completely up to the level of foreign Denka A90 Chloroprene Rubber and Bayprene 213. However, after being applied to the steel plate and rubber plate, the bonding retention time of the adhesive coating is significantly lower than that of the adhesive made of Denka A90 Chloroprene Rubber and Bayprene 213, and it is more obviously affected by the ambient temperature and humidity, which increases the difficulty of rubber lining construction of large equipment and increases the quality risk. It can be seen that there is still a lot of room for research and improvement in the material variety and application characteristics of domestic fluoroprene.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com  

What is Neoprene? Neoprene, also known as polychloroprene, is a synthetic rubber made by the free radical polymerization of chloroprene and is used in a wide variety of applications. It was first introduced by DuPont and was used by the U.S. military during World War II the following decade. Although it is one of the earliest synthetic rubbers, it is still very popular today. Neoprene has a wide range of applications due to its strong physical properties, chemical resistance, and flame retardancy. Neoprene is typically molded by injection molding, transfer molding, or compression molding.     Properties of Neoprene Neoprene has many excellent properties that make it a widely used synthetic rubber. As with any polymer, there are some disadvantages to consider when considering using Neoprene for your application. Click here to learn more about how to choose the right type of rubber to manufacture your product.   Common Applications of Neoprene Neoprene is a very commonly used rubber polymer that has a wide range of uses. It is resistant to water, fire, ozone, sunlight, and many other chemicals, making it a very versatile material. These applications include refrigeration seals, Freon/air conditioning, engine mounts, engine coolant, oil and chemical tank linings, automotive gaskets and seals, and weather stripping.   Other examples of neoprene applications include: Water Sports(Chloroprene Rubber SN-242A). Neoprene is commonly used in wetsuits due to its waterproof and insulating properties. It is also used in a variety of equipment for scuba diving, fishing, surfing, boating, and other water sports. Everyday Use(Chloroprene Rubber SN-241). Neoprene is used in many household items we use every day, including mouse pads, smartphone cases, laptop bags, remote controls, dishwashing gloves, and even musical instruments. Face Masks(Chloroprene Rubber SN-243). During the COVID-19 pandemic, neoprene was found to be an effective material for making face masks. Since then, many manufacturers have used it to produce protective masks.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com