We’ve all seen the effects of the sun on plastic. It fades, cracks, and eventually crumbles. But what if there was a plastic that could stand up to the elements, a material that could withstand the harsh realities of outdoor life? Enter ASA, the “weatherproof” plastic that’s changing the game.
ASA vs. ABS: The Battle of the Plastics
ASA and ABS are both popular plastics, known for their strength and durability. But ASA has a secret weapon: it’s incredibly weather-resistant. While ABS can fade and crack under prolonged exposure to sunlight, ASA holds its own, thanks to its unique molecular structure.
The Secret Sauce: Saturated Acrylic Ester Rubber
The key to ASA’s weather resistance lies in its molecular makeup. Unlike ABS, which contains unsaturated double bonds, ASA features a saturated acrylic ester rubber main chain. This means it’s less susceptible to degradation from UV rays and other environmental factors.
ASA: A Plastic Built to Last
This weatherproof plastic is making waves in a variety of industries:
- Outdoor Equipment: ASA is the perfect choice for outdoor furniture, playground equipment, and other products that face the elements.
- Automotive: From car bumpers to exterior trim, ASA is helping to create vehicles that are both stylish and durable.
- Construction Materials: ASA is being used in building facades, siding, and other applications where weather resistance is crucial.
- 5G Antenna Covers: ASA’s ability to withstand harsh weather conditions makes it ideal for protecting sensitive electronic equipment.
The Future of ASA: A World of Weatherproof Plastics
ASA is a game-changer for plastics, offering a durable and weather-resistant solution for a wide range of applications. As we continue to explore the possibilities of this innovative material, we can expect to see even more exciting applications in the years to come.
The Takeaway: ASA – The Plastic That Can Handle Anything
When you need a plastic that can stand up to the elements, ASA is the answer. It’s durable, weather-resistant, and ready to take on whatever Mother Nature throws its way. Get ready for a world of weatherproof plastics, powered by the innovation of ASA.
ASA is the abbreviation of acrylate – styrene – acrylonitrile terpolymer. ASA resin has similar mechanical properties to ABS resin, but has obvious advantages over ABS resin in terms of weather resistance. Butadiene rubber in ABS resin provides toughness, styrene improves processing fluidity, and acrylonitrile improves chemical stability. Since the butadiene block contains a large number of double bonds in the molecule, ABS products are prone to yellowing and degradation when exposed to direct sunlight when used outdoors, resulting in changes in product appearance and a decrease in mechanical properties.
The main chain of ASA replaces the butadiene double bond structure in ABS with a saturated acrylate rubber segment structure, thus greatly improving the weather resistance. The main reason is that the dissociation energy of hydrogen atoms on the main chain of ASA ‘s acrylate rubber is 376kJ/mol , while the dissociation energy of hydrogen atoms on the ortho position of the double bond of butadiene rubber in ABS is only 163kJ/mol . This results in Acrylate rubber can only degrade under high-energy light irradiation with a wavelength below 300nm , while butadiene rubber can degrade under light with a wavelength below 700nm . Under actual sunlight, the main energy of the light wavelength reaching the earth is basically above 300nm , so ASA materials containing acrylic rubber can withstand long-term sunlight. This is the main reason for the difference in weather resistance between ASA materials and ABS materials.
ASA and ABS molecular structure
There are many methods for synthesizing ASA , and currently the emulsion grafting and blending method is the mainstream method.
( 1 ) Resin blending method. The resin blending method is a purely physical blending method that blends PBA (polybutyl acrylate) rubber and SAN (styrene – acrylonitrile) resin at high temperature. The product performance is not ideal, which limits the application of this process.
( 2 ) Emulsion grafting and blending method. The process of preparing ASA resin using emulsion grafting and blending is similar to the process of preparing ABS resin. The process is: Synthesize PBA latex → Emulsion graft copolymerization → Coagulation → Filtration → Washing → Drying → Blending with SAN → Granulation → ASA resin. The control of PBA latex particle size and appropriate cross-linking are the keys to the synthesis of PBA rubber phase. Technology determines the performance of ASA resin. In 1962 , BASF in Germany was the first to realize the industrial production of ASA resin using the emulsion grafting and blending method.
The emulsion grafting and blending method has a simple process, the reaction is easy to control, and process parameters such as grafting rate, rubber phase particle size and distribution are easy to adjust. Different grades and properties can be produced by adjusting the ratio of ASA core-shell graft copolymer to SAN resin. ASA resin products. At present, the emulsion grafting and blending method is the main production method of ASA resin.
( 3 ) Direct synthesis method. The direct synthesis method of ASA resin is to preset the ratio of PBA/St-AN core-shell ingredients, and then use different polymerization methods (emulsion polymerization, suspension polymerization or bulk polymerization) to synthesize, including bulk method, suspension method, bulk suspension method, Emulsion suspension method, etc., are suitable for the production of special materials and have high technical requirements. The emulsion suspension method absorbs the advantages of the emulsion grafting method and the suspension polymerization method, and switches to suspension polymerization in the middle stage of the emulsion polymerization. The particle size of the latex produced is appropriate, and the post-processing process is simple, but the process is complicated.
ASA resin direct synthesis method
ASA resin is generally used in combination with SAN . Compared with ABS resin, ASA resin is more expensive and has fewer general models. ASA rubber powder is generally used in combination with styrene – acrylonitrile copolymer (SAN) to replace ASA for PC/ASA alloying modification. Compared with directly using ASA resin to prepare PC/ASA alloy, using ASA rubber powder and SAN at the same time has the advantages of high formula flexibility and high adjustability. For PC/ASA alloys, different proportions of PC and ASA , as well as different proportions of ASA rubber powder and SAN in ASA, will bring great differences to the performance of PC/ASA alloys. By blending rubber powder with SAN of different specifications, ASA resin for various purposes can be obtained. By blending and granulating SAN and ASA with high melt index, you can get high-flow ASA materials. By blending and granulating SAN and ASA with high AN content, you can get high rigidity and high resistance. Chemical ASA material.
The main applications of ASA : mostly related to outdoor scenes.
ASA resin material has excellent weather resistance and easy coloring. It can directly produce brightly colored products without spraying. It has good ultraviolet resistance. It can be exposed to sunlight for 9-15 months with almost no change in mechanical properties and stable color. The following areas have great application potential.
( 1 ) Outdoor equipment. Widely used in gardening irrigation equipment, road signs, traffic lights, power lawn mowers, sports equipment, advertising boxes, etc.
( 2 ) Cars. The surface of ASA resin can achieve high surface gloss and surface hardness without spraying treatment. The mechanical properties and weather resistance of the material meet the standards of automobile OEMs. It can replace certain metal materials in automobile parts products and is widely used in automobile aftermarket. It can be used in exterior parts such as mirrors, door pillar decorative panels, radiator grilles, window frames, tailgates, light housings, etc., as well as in interiors such as dashboards and decorative panels.
( 3 ) Building materials. ASA resin is mainly used in the building materials industry to produce synthetic resin tiles and profiles. It is widely used in building materials such as roof tiles, exterior wall hanging panels and window materials to make buildings safer, have longer service life and shorten construction time.
( 4 ) 5G antenna cover. The 5G antenna cover protects the antenna system from the impact of the external environment (such as sunlight, wind and snow, etc.) and extends the life of the antenna. It also needs to ensure the permeability of electromagnetic waves. Therefore, the antenna cover material should meet the dielectric and mechanical properties. , weather resistance, processability and other conditions. ASA material has a low dielectric constant and small dielectric loss. It is an electromagnetic insulating material and will not form microcurrents under the action of electromagnetic waves to form electrostatic shielding inside the wireless terminal. Therefore, it can be used as the shell of 5G communication equipment.
The production of ASA : mainly foreign companies, many domestic companies have already produced large-scale products. In 1962 , BASF of Germany pioneered the industrial production of ASA resin, registered as Luran Ⓡ S ASA . Subsequently, Hitachi Chemical Company of Japan and GE Company of the United States also realized industrial production. At present, the main manufacturers of ASA include BASF , General Electric (now SABIC ), Ineos Styrolution, Dow Chemical, Hitachi Chemical of Japan, and Techno-UMG Co., Ltd. of Japan (the merger of the two major styrenic material manufacturers of Japan’s Daconon and UMG (formed), Kumho of South Korea, LG of South Korea, Chimei of Taiwan, Taihua of Taiwan, etc. In recent years, mainland manufacturers have begun to rise. For example, Shandong Donghai Plastic Industry and Guangzhou Entropy Energy have successively achieved large-scale production. In particular, Shandong Donghai’s ASA high rubber powder has multiple specifications and brands, which are excellent in physical and mechanical properties, weather resistance, and colorability. In terms of price and performance, it surpasses many similar foreign products. In September 2024 , the construction of the first ASA resin integrated device in China started. The project is located in Lijin, Dongying, Shandong. It is an annual key project of Lihua Yilijin Refining and Chemical Co., Ltd., with an annual production capacity of 100,000 tons / year and a total investment of more than 2.2 billion. Yuan, this project has also been included as one of the major projects in Shandong Province by 2024 . In June 2024 , Zhejiang Giltai ASA and other new functional materials projects were signed in Guannan County, Lianyungang City. The project will build 20,000 tons /ASA materials and an annual output of 20,000 tons of acrylic copolymer (ACR) materials.
As of 2023 , the global ASA resin market size is 7.18 billion yuan, equivalent to approximately 300,000 tons, of which the Chinese market size is approximately 100,000 tons. Overall, compared with the global ABS market of 11 million tons, there is huge room for ASA to further replace ABS . The market price of ASA is close to 20,000 yuan / ton, which is much higher than the current 11,000 yuan / ton of ABS . With the further improvement of domestic resin supply capacity, there is a high possibility that the domestic ASA resin market will expand to 500,000 tons.