PC: Breaking Away from Imported Production Technologies is Seen as Urgent

By Ma Dou, East China Engineering Science and Technology Co., Ltd.

Production

Domestic companies made breakthroughs in polycarbonate (PC) production technologies during 2013-2016, and quite a few built new polycarbonate units.
Table 1 shows the major producers of polycarbonates in China in 2016.

Consumption

With rapid growth in China’s construction, automobile and optical media sectors, demand for polycarbonates has increased steadily in recent years. Apparent consumption grew 5% in 2015, and the consumption pattern diversified a bit. Figure 1 shows the structure of polycarbonate consumption in China in 2016.
Owing to rapid development of the mobile communication sector, consumable electronic products have become a major driver for growth of polycarbonate consumption.

R&D and applications

Most of the technology for producing polycarbonates in China is imported. Zhejiang University, Tianjin University, China Bluestar Chenguang Research Institute of Chemical Industry and CAS Changchun Institute of Applied Chemistry have all researched technologies for synthesizing polycarbonates.  And Jiangsu Danhua Group Co., Ltd. and CAS Chengdu Institute of Organic Chemistry have achieved outstanding advances in non-phosgene processes for making diphenyl carbonate, a key raw material for polycarbonates.
China Bluestar Chenguang Research Institute of Chemical Industry has been developing a new 500-1 000 t/a commercial process for the continuous polycondensation of polycarbonates through ester exchange. Two pilot units (100 t/a and 1 000 t/a) were constructed, and qualified polycarbonates were produced. China Bluestar Chenguang Research Institute of Chemical Industry then developed process software for 100 kt/a production of polycarbonates by ester exchange, in collaboration with China Design Institute of Textile Industry.

Table 1    Major producers of polycarbonates in China, 2016

Producer    Capacity (kt/a)    Production process and year production started
Zhejiang Jiaxing Teijin Polycarbonate Co., Ltd.    160    Phosgene process, 2005/2006/2009
Changzhou Synthesis Chemical Plant    3    Phosgene process, 1995
Shanghai Shenju Chemical Factory Co., Ltd.    1.5    Ester exchange process, 2003
Chongqing Changfeng Chemical Co., Ltd.    3.5    Ester exchange process
Bayer Polymers (Shanghai) Co., Ltd.    200    Ester exchange process, 2006/2008
Sichuan Mianyang Chenguang Fada Industrial Co., Ltd.    10    Ester exchange process, 2006
Sinopec Mitsubishi Chemical Polycarbonate Co., Ltd.    60    Non-phosgene melt ester exchange process, 2011  
Tongling Jintai Chemical Industrial Co., Ltd.    3    Non-phosgene process, 2007
Ningbo Zhetie Daphoon Chemical Co., Ltd.    100    Non-phosgene ester exchange process
Luxi Chemical Group Co., Ltd.    65    Ester exchange process
Qingdao Hengyuan Chemical Co., Ltd.    100    Non-phosgene ester exchange process
Globe Joint Chemical Co., Ltd.    130    Ester exchange process
Lihuayi Weiyuan Chemical Co., Ltd.    60    To be completed in 2018
Wanhua Chemical Group Co., Ltd.    200    To be completed in 2018
Lutianhua China Bluestar New Material Co., Ltd.    200    To be completed in 2018


CAS Changchun Institute of Applied Chemistry researched production of polycarbonates through interfacial polymerization of bisphenols and phosgene, making essential technical breakthroughs in phosgene-process polycarbonate production and patenting the technique. The technology is easy to commercialize and has bright development prospects.
CAS Changchun Institute of Applied Chemistry and Gansu Yinguang Juyin Chemical Industry Co., Ltd. of China North Industries Group Corporation jointly researched and successfully piloted a patented 500 t/a R&D technique for making polycarbonates. Wet commissioning was successful in October 2008, and qualified polycarbonate powders were produced.
Tianjin University is actively developing the melt ester exchange process for making polycarbonates. A 10 t/a pilot test was already completed. Technical conditions for constructing 1 kt/a units of CD-grade polycarbonates have been mastered.
Zhejiang University has long concentrated on researching and developing synthesis processes polycarbonates through a CO2 route. As one outcome, a synthesis process for aliphatic polycarbonates using CO2 and epoxides is now being commercialized.
Jiangsu Danhua Group Co., Ltd. has completed a 150 t/a pilot project for synthesis of diphenyl carbonate as raw material for polycarbonates through a dimethyl oxalate process, and qualified diphenyl carbonate has been successfully obtained. Some of the product is supplied to China Bluestar Chenguang Research Institute of Chemical Industry for synthesizing polycarbonates.
CAS Chengdu Institute of Organic Chemistry has constructed a 5 kt/a production unit and prepared a 10 kt/a process software package. Using such technology to produce diphenyl carbonate, the single-pass conversion rate of phenol is higher than 46%.
With the rapid growth of polycarbonate consumption in China, vigorous development of the polycarbonate industry is extremely urgent and necessary. Non-phosgene production processes are green processes in line with environmental requirements; they are also a major orientation in the future development of polycarbonates production processes. New applications of polycarbonates should be higher in functionality and more specialized.