By Yang Weilan, Zhang Bei, CNCIC Consulting

From the angle of the industrial chain based on propylene carbonylation, downstream products of intermediate n-butyraldehyde include n-butanol, isooctanol, trimethylolpropane (TMP) and polyvinyl butyral (PVB). Downstream products of isobutyraldehyde mainly include isobutanol and neopentyl glycol (NPG). This article highlights markets of other products of the butanol/octanol value chain except those that can be used as plasticizers.

TMP

   TMP is a chain extender commonly used in the resin sector. It can improve the toughness, anticorrosion and tightness of resins and has great stability to hydrolysis, pyrolysis and oxidation.

   The total capacity of TMP in China was around 130 kt/a in 2017, the output was around 80 kt and the average operating rate was 62%. Table 1 shows the major TMP producers in China.

   Table 1   Major TMP producers in China in 2017

   In China TMP is mainly used in the production of PET and PU coating resins and also in other sectors such as multi-functional acrylates/methacrylates and neopolyol esters for lubricants. The consumption of TMP in China was 64 kt in 2016 and is expected to reach 88 kt in 2021 with an average annual growth of 6.6% during 2016-2021. Major application sectors of TMP in China are as follows:
   PU coating resins: TMP is a raw material for the production of two-component PU coating/adhesive curing agents. The preparation of TDI-TMP affixture is convenient and the cost is lower than other polyisocyanate curing agents. Today China can already produce products with a free TDI content of below 0.7%.
   PET resins and alkyd resins: TMP is an intermediate for baking alkyd resins for industrial uses and can also be used as intermediate for saturated PET resins. Owing to its high resistance to UV and chemicals, TMP is extremely suitable for outdoor applications. It can also improve the heat resistance of resins and remain stable in baking conditions.
   Multi-functional TMPTA/TMPTMA: TMPTA or TMPTMA is produced through the esterification of acrylates or methacrylates. They are active diluents with multi-functionality used most often in radiation curing. In coating recipes, TMPTA or TMPTMA usually holds a share of 20-60%. TMPTA is used in UV/EB curing whereas TMPTMA with a relatively low curing rate is only used in EB curing.
   Neopolyol esters for lubricants and others: TMP is also used to produce trimethylolpropane diallyl ether (TMPDE). TMPDE is also called resin air drying agent. It is mainly used in unsaturated resins, alkyd resins and water-soluble resins to improve their drying and water-resistant behaviors with no need of adding wax for polishing.

PVB

   PVB is produced through polycondensation between polyvinyl alcohol (PVA) and butyraldehyde. It is mainly used as diaphragm for bonding laminated glass in national defense or civil industries.
   The total capacity of PVB in China was around 90 kt/a in 2017, the output was around 60kt and the overall operating rate was 67%. Major producers included Kingboard Holdings Co., Ltd., Anhui Wanwei Updated High-Tech Material Industry Co., Ltd., Huakai Plastic (Chongqing) Co., Ltd. and Qingdao Haocheng Industrial Co., Ltd. See Table 2 for detail. More PVB projects are being constructed or planned for construction in Jiangxi, Jilin, Henan and Sichuan today and the total planned capacity is around 60 kt/a.

   Table 2    Major PVB producers in China in 2017

   The total consumption of PVB in China was around 90 kt in 2017. Of the total, the import amount was around 30 kt. Imported products mainly came from Solutia, Sekisui and Kuraray. It is expected that the consumption will reach 110kt in 2022 and the average annual growth will be 4.0% during 2017-2022. Drives for the demand growth are mainly manifested in following aspects:
   Laminated safety glass for automobiles: The major demand of PVB prepreg is in transport means. With the booming development of the automobile industry in China, the demand of PVB laminated glass in the market of automobile components is huge. Today front windshield glass of automobiles totally use PVB laminated glass functional diaphragm. The demand growth of PVB functional diaphragm in the automobile industry is one of main reasons for the total growth amount of PVB prepreg in China.

   Laminated safety glass for buildings: With the constant acceleration of urbanization, the development of the building industry in China will have a bright prospect. The consumption of glass for buildings will also have a year-on-year increase. The use of safety glass is also in line with the theme in the development of building materials towards environmental protection and energy conservation.
   Others: PVB is also used in other sectors such as photovoltaic glass, spaceflight, national defense and high-tech. For example, it is used in airplanes, spacecrafts, military instruments, solar cells and solar receivers and also composite damping steel plates in industrial sectors.

NPG

   NPG has very high chemical stability and heat stability, resulting in excellent properties of its derivatives. The total capacity of NPG in China was around 400 kt/a in 2017 and the output was 200-240 kt. Table 3 shows the major NPG producers in China.

    Table 3   Major NPG producers in China

   The consumption of NPG in China was 229 kt in 2016. Around 156 kt was used to produce PET resins for coatings, accounting for 68.1% of the total. The consumption in others accounted for 31.9%. It is expected that the consumption of NPG in China will reach 330 kt in 2021 and the average annual growth will be 7.6% during 2016-2021.