Views: 266 Author: Site Editor Publish Time: 2023-08-14 Origin: Site
Neopentyl Glycol (NPG), a white crystalline solid, odourless and hygroscopic, is a unique polyol product that provides excellent performance in many end-use applications due to its high chemical and thermal stability, and is widely used in powder coatings, textiles, and the construction industry. It is also an important raw material for the production of polyester fibre resins, which are widely used in the production of coatings, unsaturated polyester resins, alkyd resins, lubricants and plasticisers.
NPG is mainly used in the production of unsaturated polyester and saturated polyester, used in the formulation and production of powder coatings, polyurethane ester resins, glass fibre reinforced unsaturated resins, etc., and also used in the production of oil-free alkyd resins, which are widely used in the industries of coatings, insulating materials, and printing inks.
As the coating resin made of NPG as the main raw material is the basic ingredient for the preparation of powder coatings and high solid coatings, and these coatings have excellent fluidity, flexibility, chemical stability (especially hydrolysis resistance), weather resistance, chlorine resistance, thermal stability and resistance to ultraviolet irradiation, etc., they are widely used in the fields of automobile parts, metal equipments, large-sized instruments, electric motor beds, water heaters, agricultural equipments and toys.
Neopentyl Glycol is mainly used in the polyurethane sector for the production of polyester polyols, which are mainly used in non-foamed polyurethanes. Polyurethanes based on neopentyl glycol-containing polyurethanes have excellent hydrolytic stability, low glass transition temperature, low melting point, excellent thermal and UV stability, and chemical resistance. It is mainly used in the production of thermoplastic polyurethanes, polyurethane coatings, cast elastomers and adhesives.
NPG is also used in the synthesis of plasticisers to give PVC excellent low temperature resistance with low volatility and migration. This advanced plasticiser is also used in polyurethanes.
Neopentyl glycol diester resins are used in the production of advanced synthetic lubricants that have excellent thermal stability in addition to low freezing points, high viscosity indices and high flash points.
NPG is an excellent solvent for selective separation of aromatic and cycloalkyl hydrocarbons.
In addition, NPG can be used in the synthesis of ibuprofen, a new antipyretic and analgesic drug.
NPG derivatives can be used as spices, drugs, flame retardants, aviation lubricants, plasticisers, inks, insulating materials, etc. They are widely used in paints, automobiles, textiles, pesticides, plastics and petroleum.
Mixed diol diesters containing Neopentyl Glycol are also frequently used as thickeners in synthetic lubricants.
Neopentyl Glycol Diacrylate can be used as a cross-linking agent in free radical polymerisation systems such as acrylate polymerisation and UV curable coatings.
At present, domestic and foreign industrial production of NPG are used isobutyraldehyde process, that is, isobutyraldehyde (IBA), formaldehyde (FA) as a starting material, the alkaline catalyst catalytic condensation to generate intermediate 2,2-dimethyl-3-hydroxypropanal (commonly known as hydroxyl pivalaldehyde, referred to as HPA), and then reduced to NPG. and because HPA is reduced by formaldehyde dismutualisation and catalytic hydrogenation, so the process is also divided into dismutualisation method, Hydrogenation method.
The disproportionation method has small investment and mild process conditions, but the by-product sodium formate exists in large quantities in the reaction products, which brings difficulties to the refining of NPG. From product quality, economic indexes to environmental requirements, it is not competitive with the condensation hydrogenation process.
The condensation hydrogenation process has high yield and no by-product sodium formate, and is characterised by low consumption, low energy consumption, long catalyst life and high conversion rate of hydrogenation reaction. However, the process is long, the investment is high, and the technology is difficult, and it needs to solve the hydrogen source and high-performance catalyst.
Polyester resin for powder coating is the main downstream product of Neopentyl Glycol, with a consumption share of nearly 90%. According to statistics, the total production capacity of polyester resin for powder coating in 2022 exceeds 2 million tonnes. Due to the superior environmental performance of powder coatings, polyester resin capacity has been expanding rapidly in recent years, and the sales of polyester resin for powder coatings will increase by more than 10% in 2023, further expanding the demand for Neopentyl Glycol.
