Neopentyl glycol

Thread Content

　　Neopentyl glycol I. Introduction to Neopentyl Glycol Product name: Neopentyl glycol (Neo, or NPG) English product name: Neopentyl glycol; 2,2-Dimethyl-1,3-propanediol Chemical name: 2,2-Dimethyl-1,3-propanediol Formula: C5H12O2 Molecular weight: 104.15 CAS number: 126-30-7 Physical and chemical properties: White crystalline solid, odorless, and hygroscopic. Melting point 124–130°C. Boiling point 210°C. Density (21°C): 1.06 g/cm3. Flash point 129°C. Autoignition temperature: 399°C. Sublimation temperature 210°C. It is soluble in water, lower alcohols, lower alkanes, ethers, and aromatic compounds. 　　Toxicity protection: Low toxicity. The oral LD50 in rats is ≥6400 mg/kg. The oral LD50 in mice is 3200–6400 mg/kg. It has low irritation to the skin. However, excessive consumption can stimulate the central nervous system, causing symptoms such as vomiting, fatigue, drowsiness, difficulty breathing, tremors, kidney congestion and bleeding, liver fatty changes, urinary retention, bronchitis, and pneumonia; in severe cases, it can even lead to death. 　　Applications of the product: It is mainly used in the production of unsaturated resins, polyester powder coatings, oil-free alkyd resins, polyurethane foam plastics, plasticizers for elastomers, synthetic plasticizers, surfactants, insulating materials, printing inks, polymerization inhibitors, and additives for synthetic aviation lubricants. It is also used in the pharmaceutical industry. At the same time, neopentyl glycol is also an excellent solvent that can be used for the selective separation of aromatic and cycloalkyl hydrocarbons. 　　Quality standard: HG/T2309-92 Packaging and storage: In solid form, it is packaged in bags – with a plastic bag as the inner layer and a woven bag as the outer layer; the weight per bag is 25KG. 　　The liquid is packaged in galvanized iron drums, at 25 kg per drum. 　　Store in a cool, well-ventilated place, protected from sunlight, heat, and moisture. Store and transport in accordance with the regulations for general chemicals. 　　II. The three major production methods for neopentyl glycol. 　　1. Internationally, there are mainly three approaches to the production of neopentyl glycol, among which the disproportionation process (methanol method) is unique to China. 　　In China, the producers of neopentyl glycol are essentially in a tripartite competition, roughly divided into three groups: the hydrogenation process: Jihua BASF. 　　Disproportionation process (methanol method): The methanol-based process represented by the Shandong Chemical Industry Research Institute is the latest improved version of the disproportionation process. 　　Disproportionation process (aqueous method): The aqueous method process represented by Fufeng Baiste (formerly Yongliu). 　　2. Feature introduction: (1) The hydrogenation process has advantages such as a short process flow, high yield, high purity, and low cost. Disadvantages: The hydrogenation process requires high investment, has strict requirements for the external environment, and results in high product prices. Currently in the domestic market, there are many NPG manufacturers that use hydrogenation processes, such as BSF, South Korea’s LG, Japan’s Mitsubishi, and Eastman. Among them, BASF and South Korea’s LG are in fierce competition in the neopentyl glycol market. 　　(2) The disproportionation process (methanol method) overcomes the drawback of high initial investment; its product quality far exceeds national standards, and the price is low, making it highly cost-effective in many industries. Disadvantage: Lower purity compared to the hydrogenation process. Sodium formate in this process is a major highlight. It is pure white with few impurities, has a dry basis content of over 99%, and does not tend to clump; its quality is better than that of products produced by synthetic methods or as a by-product of pentaerythritol. In the international market, sodium formate from this process stands out as the best. 　　(3) The investment for the disproportionation process (aqueous method) is also low; the quality is similar to that of the methanol method, though caking occurs more easily. The method using by-product formic acid and methanol differs significantly; it yields a dark gray or gray-colored product with low purity, and its main advantage is that neopentyl glycol can be extracted from it.