Prospects of High-end Specialty Chemicals in China (Part Two)

By Zhang Fang, China National Petroleum & Chemical Planning Institute

(Continued page 24, issue 16, 2013, CCR)

7. High-end rubber chemicals

   “Rubber chemicals,” in the broadest sense, includes additives used during rubber processing, which can be classified in six categories – curing additives (accelerators, etc.), protective additives (antioxidants, etc.), processing additives (plasticizers, softeners, etc.), reinforcing fillers (carbon black, etc.), binders (triazine-based binders, etc.) and other additives (colorants, etc.). The total output of rubber chemicals in China was almost 5 million tons in 2012, of which reinforcing fillers (carbon black, silica, etc.) accounted for about 80%. “Rubber chemicals,” in a narrow sense, includes additives consumed in smaller volumes and excludes reinforcing fillers such as carbon black and silica. Usually, the rubber processing industry makes statistics of carbon black separately from the statistics about other additives. The output of rubber chemicals in the narrow sense was 900 kt in 2012, of which accelerators and antioxidants accounted for 80%.
   In China, the rubber chemicals sector is more developed than the plastics additives sector. China consumes about half of the world’s rubber chemicals, and most of them are eco-friendly. One of the most important accelerators, N-(ethylene oxide)-2-benzothiazole sulfenamide (NOBS), which was wildly used in China ten years ago, has been gradually replaced by N-tert-butyl-2-benzothiazole sulfonamide (NS), a new, safe curing accelerator, since NOBS was found to be carcinogenic.
   China’s development of high-end rubber additives should be in line with three principles:
First, in order to support the development of green tires, the product structure of reinforcing fillers and binders should be optimized. For example, replacing carbon black with silica will be the trend since it reduces the rolling resistance of tires. In the future, the share of silica in reinforcing fillers will continue to increase, promoting the consumption of silane coupling agents accordingly.
   Second, clean production processes should be popularized. The traditional production process of antioxidant 4020 (N(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine), the most important rubber antioxidant, uses formanilide as the starting material and produces tremendous quantities of waste water, gas and residues. In recent years, various new synthesis routes for antioxidant 4020 have been developed. The most eco-friendly route that is economically competitive is to synthesize 4-amino-diphenylamin using nitrobenzene and aniline; then 4-amino-diphenylamin is reacted with methyl isobutyl ketone to form antioxidant 4020. Several production units using this synthesis route have been put into production in recent years.
   Last but not least, the development of eco-friendly rubber additives should be promoted. In particular, two types of eco-friendly processing additives should be developed as priorities: (1) cycloparaffin oil or eco-friendly aromatic rubber oil, to replace aromatic hydrocarbon rubber oil; (2) di(o-benzamidophenyl)disulfide (DBD) to replace plasticizer B, i.e. pentachlorobenzenethiol.

8. High-end water treatment agents

   Water treatment agents are normally used to treat industrial water, domestic water and waste water. The top four types of water treatment agents according to their market share, flocculants, scale inhibitors, corrosion inhibitors and biocides, account for about 70% of the total consumption of water treatment agents. Other water treatment agents include adsorbents, dispersing agents, antifoaming agents, oxygen scavengers, sludge conditioning agents, chelating agents and so on. In industrial water treatment, scale inhibitors and corrosion inhibitors are used most often; flocculants and biocides are used more often in the treatment of waste water and domestic water, respectively.
   Water treatment agents can improve water quality to meet stand requirements of drinking or industrial use while increasing the cycle number of industrial circulating water and achieving harmless disposal and recycling of waste water. Therefore, water treatment agents are vital to save energy and reduce industrial emissions.
   In the future, the trends for water treatment agents will be high-performance and eco-friendly. Three types of high-end water treatment agents should be developed as priorities:
   (1) Flocculants. Currently, inorganic flocculants such as polyaluminium chloride dominate China’s flocculant industry. In the future, organic flocculants with higher performance such as polyacrylamide (especially cationic polyacrylamide) should be developed.
   (2) Corrosion and scale inhibitors. The waste water discharged during the production of phosphorous corrosion and scale inhibitors, which are widely used in China and expected to be gradually replaced, can lead to water eutrophication. The direction should be eco-friendly corrosion and scale inhibitors such as polyaspartic acid.
   (3) Chelating agents. Due to the urgency to treat water that has excessive levels of heavy metals, the development of natural and efficient chelating agents such as chitosan should be accelerated.

9. High-performance concrete additives

   Concrete additives can be divided into four categories: (1) additives to improve concrete workability such as superplasticizers; (2) additives to adjust setting time and hardening performance of concrete such as retarders, early-strength agents and quick-setting agents; (3) additives to improve durability of concrete admixtures such as waterproof agents and rustproof agents; (4) other additives including bulking agents, antifreezes and coloring agents.
   The annual output of concrete additives already exceeds 10 million tons in China, of which superplasticizers account for two thirds. China’s superplasticizer industry is breaking into a new era, with naphthalene-based superplasticizers and polycarboxylate superplasticizers accounting for one half and one fourth of the total consumption, respectively. However, in developed countries, polycarboxylate superplasticizers, which are high-performance and eco-friendly, dominate. China has made the use of polycarboxylate superplasticizer in expressways and high-speed railways compulsory.

10. High-end coatings

   (1) High-performance coatings
   Over half of China’s coating output is used in buildings. Normally, the exterior coatings of buildings must offer higher performance than interior coatings. Building exterior coatings can be divided into four categories according to their film-forming ingredients – acrylic coatings, silicone-acrylic coatings, fluorine-silicone coatings and fluorinated coatings, in the order of increasing performance and price. Among these, China urgently needs to develop the last three.
   Currently, the upgrading of building exterior coatings is presented two opportunities. The first is the declining price of organosilicone, enabling the popularization of silicone-acrylic coatings by replacing acrylic coatings. The second opportunity originates from the industrial production of fluorine-silicone coatings. Fluorine-silicone coatings are expected to become the most important building exterior coatings since they have higher performance/price ratio than silicone-acrylic coatings and fluorinated coatings, and they can protect a building’s surface from stains and advertising stickers.
   Moreover, the consumption of high-end coatings in industries including aerospace, shipbuilding and automotives relies heavily on imports. China urgently needs to develop these high-end coatings.
   (2) Eco-friendly coatings
   Eco-friendly coatings, including high-solid coatings, waterborne coatings, powder coatings and radiation cured coatings, should be developed energetically. In the near future, more than half of the coatings used in China are expected to be eco-friendly, and highly polluting coatings like lead-containing coatings should be phased out as soon as possible.
   (3) High-performance inorganic pigments
Inorganic pigment can significantly affect a coating’s properties such as color and opacity. About 60% of the total output of titanium dioxide, the most important inorganic pigment, is used in coatings.
   Titanium pigment is extracted by either the sulfuric acid (sulfate process) or the chlorine (chloride process). The chloride process, which produces less exhaust and can yield products with good color durability and opaqueness, is the major process used in developed countries. However, in China, there is only one 30 kt/a unit using the chloride process, while most titanium pigment output is acquired from the sulfate process.
   The chloride process can occur in a melting furnace, or in a boiling chlorination furnace, which is more high-tech. The only chloride process unit in China uses a boiling chlorination furnace, and several more units of this type are under construction. Since most of China's titanium resources are in low-grade ilmenite deposits, a process which can treat low-grade titanium ores should be developed. In 2011, The apparent consumption of titanium dioxide in China reached 1.59 million tons; output, 1.76 million tons; imports, 230 kilo tons; exports, 400 kilo tons. A large amount of titanium dioxide made through the sulfate process has been exported, while that made using the chloride process is mostly imported.
   (4) Nano-sized inorganic fillers
   Inorganic fillers are also important raw materials of coatings. They can improve textural properties of coatings and reduce production costs. The most important inorganic filler, calcium carbonate is widely used in coatings, plastics, sealants, inks, paper and so on.
   Calcium carbonate is universally categorized according to the two manufacturing processes. One is light calcium carbonate, which is achieved by chemical synthesis. The other is heavy calcium carbonate, which is achieved by physical pulverization. According to their powder size, calcium carbonate products can be divided into ordinary product, ultra-fine (micro-sized) product and nano-sized product. Nano-sized calcium carbonate can be produced only through chemical synthesis.
Ultra-fine or nano-sized calcium carbonate can significantly increase the mechanical properties of downstream products like coatings, inks and plastics. The production of nano-sized calcium carbonate in China started in the end of the last century. To meet varied market demands, various production processes have been developed, including bubbling, stirring, microbubble stirring, “supergravity” and spraying. With the continuous maturing of production processes and lowering of production costs, nano-sized calcium carbonate becomes more and more popular, and it is already applied massively in plastics, coatings, sealants, papers and inks. In 2012, its output in China exceeded 500 kt, with a growth rate much higher than that of traditional calcium carbonate. Considering its high performance/price ratio, the consumption of nano-sized calcium carbonate is expected to increase 12 - 15% each year in the next few years.

11. High-end dyes

   (1) High-performance dyes with new chemical structures should be developed, especially sensitive fluorinated dyes and their intermediate, cyanuric fluoride.
   (2) In order to meet demands from downstream industries, new products like PTT fiber, polylactide fiber, soybean fiber, bamboo fiber and hybrid fibers, and new dyeing processes like digital inkjet printing technology and additive-free microcapsule dyeing should be developed.
   (3) In order to meet the demand from downstream market segments, various dye commodities should be developed energetically.

12. High-end pesticides

   (1) Efficient, safe, economical and eco-friendly pesticides. The development of new fungicides, insecticides to cope with difficult pests or invasive pests, new pesticides for non-staple crops and pesticides used in non-agricultural fields should be focused on first. In particular, fluorine-containing pesticides are worthy of attention.
   (2) Eco-friendly pesticide preparations. In order to replace traditional preparations such as dustable powders, emulsifiable concentrates and wettable powders, eco-friendly pesticide preparations like water dispersible granules, suspensions, water emulsions, microcapsules and large granules (tablets), as well as their accompanying new additives, should be developed right away.

13. High-end intermediates

   “Intermediates,” in a narrow sense, includes those for the production of pesticides, pharmaceuticals and dyes, while the term, in a broader sense, includes those for all organic synthesis processes. “High-end intermediates” includes intermediates for the production of high-end pesticides, pharmaceuticals, dyes, liquid crystal materials, etc.
   (1) New intermediates have opportunities.
   With the continuous innovation in downstream products such as pesticides, pharmaceuticals, dyes and liquid crystal materials, new intermediates are developed all the time. Because most pesticides and pharmaceuticals made in China are generic drugs and liquid materials, they are one generation behind those made in Japan and Korea. Hence, any new intermediates developed here are likely to be exported to foreign manufacturers before being consumed domestically. Compared to other intermediates, fluorinated liquid crystal intermediate which has economic advantage is a focus.
   High-end intermediates are produced in plenty of varieties, most of which are manufactured in a make-to-order business model (MTO). Due to the fast progress in the market for intermediates, their makers must have strong R&D capabilities.
Many new intermediates are characterized by fluorine atoms and heterocyclic rings within their chemical structures. Most fluorinated intermediates are aromatic compounds. In recent years, fluorinated pyridine derivatives have become a focus of development. Some fluorinated aliphatic intermediates like trifluoroacetic acid also have better opportunities for development.
   (2) The production processes of bulk traditional intermediates must become efficient and clean.
   On one hand, more and more clean production processes have been developed to replace traditional processes. For example, catalytic hydrogenation reduction has been used to replace sodium sulfide reduction and iron powder reduction.
On the other hand, continuous large-scale production processes of intermediates have been popularized. Most traditional processes are intermittent operations. Continuous large-scale production processes can lower production costs and improve quality of products. For example, continuous production of p-dichlorobenzene with significantly reduced production cost has been achieved in one Chinese company.

III. Conclusion

   1. Currently in China, the replacement of traditional specialty chemicals with new eco-friendly specialty chemicals needs to be accelerated.
   2. In order to transform and upgrade,China's high-end industries such as electronic information and new energy are in great need of high-performance specialty chemicals to replace imported products.
   3. One of the major tasks of China’s specialty chemical industry is to meet the incremental demands brought by urbanization. As one of the major driving forces for the development of China’s economy, urbanization will bring large increments of demand for concrete additives, adhesives, plastics additives, etc., and it indirectly stimulates the consumption of almost all specialty chemicals.