At present, there are many manufacturers producing neutral sizing agent AKD in Shandong and other places. In these fields, AKD is widely used by papermaking enterprises, and it is the first to realize a major change in papermaking sizing from traditional acid rosin sizing to neutral sizing. The sizing agent ASA produced by Fushun Petrochemical Company's detergent chemical plant was successfully developed by using the high-quality intermediate product linear internal olefin of the plant and combining with similar international technologies. ASA has been widely concerned by nearly 100 related research institutes and manufacturers at home and abroad since its listing. Because ASA is easy to operate and suitable for large-scale continuous production, it has played a great role in promoting the large-scale and serial development of China's paper industry and realizing the major transformation from acid rosin sizing to neutral sizing.
It is understood that ASA has been widely used in neutral sizing in paper industry abroad, and the industrial equipment for producing ASA has been scaled up as early as the early 1980s. There are many patents about this production technology abroad, and developed countries such as the United States, Japan, Britain and Spain all have their own patents, and the production process is different. One of the processes is to obtain α -olefins by paraffin cracking, and then to convert double bonds into olefins by catalytic isomerization, and to synthesize ASA to react with maleic anhydride under suitable conditions. Another process is that heavy wax is dehydrogenated under the catalytic action of dehydrogenation to produce alkane-olefin mixture, and then high-purity internal olefin is obtained by molecular sieve separation, and the internal olefin reacts with maleic anhydride to produce ASA. ASA developed by Fushun Washing Chemical Plant is produced according to the second process route. Using ASA sizing in papermaking process is similar to rosin sizing, and sizing can be completed after leaving the paper machine. Because the freight volume of ASA (purity > 96%) is relatively small, it can save a lot of transportation costs. At the same time, ASA glue needs to be emulsified in the paper production site, and the existing emulsion can be used to make paper to ensure the quality of paper products.
In recent 20 years, the foreign papermaking industry has experienced a great change from acidic to neutral (or alkaline) papermaking system centered on reactive synthetic sizing agent. This change has a wide range and a fast development speed. It can be predicted that this change will soon appear in China paper industry. The premise is that the paper mill should change the traditional sizing process of saponified rosin that is still in use at present, and the time is ripe to change this process. With the continuous improvement of market demand for paper quality and varieties, many paper mills turn to neutral sizing, and the development and popularization of neutral sizing agent has become an inevitable trend of paper industry development.