Production and Development
                   of Antioxidants
                     By Wu Wei
1. Production status
In the early 50's, China started to
         produce   naphthylamine   antioxidants   such   as
antioxidants A and D for rubber products. In later  years,
  simple  hindered  phenol  varieties  such  as  BHT  began
  production.   High  molecular  weight   hindered   phenol
varieties such as antioxidants 1010 and 1076, as  well  as
thiolate DLTP, were developed in the 70's with a  capacity
of 500 t/a at that time.
  The rapid development of the ethylene industry  in  China
has led to an expansion of synthetic materials such as PVC
, polyolefins and styrene. Synthetic materials  have  found
  more  extensive   uses   in   industry,     agriculture,
transportation and communication,  telecommunications  and
daily life. The demand  of  antioxidants  in  the  plastic
processing sector is increasing fast. To meet the  demand,
  the  antioxidant  sector  has  expanded  the   production
capacity and developed many new products.  High  molecular
  weight  hindered  phenol  varieties,   high   performance
  hydrolytic  phosphite  168  and  compound  varieties   of
hindered phenol and phosphite are examples of new products.
  BHT is mainly used in oil product processing, and also in
plastic processing and food processing.
  China has more than 15 producers of plastic  antioxidants
with a total capacity of around 13 000 t/a. The output  in
  1997  was  around  7  000  tons.   These  producers   are
distributed in Beijing, Tianjin,  Shanghai,   Jiangsu  and
Zhejiang, places close  to  petrochemical  bases.   A  new
antioxidant  unit  started  production  in  Shanghai  Ciba
-Gaoqiao Chemical Co., Ltd. at the end of 1997.   The  unit
produces  hindered  phenol  antioxidants  1010  and  1076,
  phosphite  antioxidant  168  and  compound  varieties  of
hindered phenol and phosphite  215  and  225.   The  total
capacity of the unit is 4 900 t/a. The table 1 below shows
the major antioxidant producers in China.
2. Consumption status
Neither the quantity nor the
        quality  of  domestic  antioxidants  can  meet  the
market demand.  The  import  amount  of  antioxidants  was
around 5 000 tons and the total consumption was around  12
000 tons in 1997. Imports mainly came from  large  foreign
antioxidant producers such as  Ciba- Geigy  and  Monsanto.
Since the start of production  of  Shanghai  Ciba- Gaoqiao
Chemical Co., Ltd. (a joint venture of Ciba Fine  Chemical
  of  Switzerland,   Alkylphenol  of  Japan   and   Gaoqiao
Petrochemical Corporation) in 1997, the import amount  has
been reduced. The reasons for the situation are as follows:
(1) The production of antioxidants  has  not  reached  the
economic scale in China and the  economic  performance  is
therefore poor. Except Jinhai Chemical Industrial Co., Ltd
. which has developed into a considerable size, most of the
other domestic producers only have a capacity  of  several
hundred tons a year. According to experts,  however,   the
economic capacity of antioxidant 1010 for instance  should
be more than 3 3000 t/a.
(2) Except Shanghai Ciba-Gaoqiao Chemical Co., Ltd.  which
has adopted the technology from Ciba Fine  Chemical,   all
the other producers  use  the  domestic  technology.   The
technical level is low and the product quality is unstable
. Domestic products can hardly compete with stable  quality
foreign products. Some large  resin  enterprises  are  not
willing to use domestic antioxidants because they want  to
ensure their product quality.
  The development priority in China in the next  few  years
will still be on general-purpose varieties such  as  1010,
1076 and 300. While  making  existing  products  meet  the
demand, more new products will be developed. The demand of
plastic antioxidants in China will  reach  around  15  000
tons in 2000.
3. New product development
Besides  above- mentioned  common  varieties,   antioxidant
producers and research institutes are active in developing
new products. Varieties still under  research  or  already
with  small  batch  production  include  antioxidant  259,
  antioxidant  CA,   antioxidant  330,   antioxidant  300,
antioxidant 702, antioxidant 3114,   antioxidant  245  and
antioxidant 1098.
Table 1   Major Antioxidant Producers in China
  Sr. No.               Producer                                                Major products          Capacity (t/a)
    1           Shanghai Ciba-Gaoqiao Chemical Co., Ltd.                Irganox 1010, 1076