Diphenol is not an aromatic hydrocarbon because it contains oxygen atoms and is an aromatic derivative.
Industrial 2-naphthol is refined naphthol as raw material, with 96-98% sulfuric acid sulfonation of 2-naphthol sulfonic acid, and then with sodium sulfite neutralization to generate its sodium salt, and then with sodium hydroxide alkali fusion of 2-naphthol sodium, then with sulfuric acid acidification of 2-naphthol crude products, after boiling, washing, drying, decompressed distillation of 2-naphthol products.
The pollution of this process is relatively serious and the environmental protection problem is more prominent.
American cyanamine development of 2-isopropylnaphthalene combined production of acetone 2-naphthol process, because of the cost of environmental protection and other reasons and stopped production.
At present, the main production countries of 2-naphthol in the world are China, India, Japan, Italy and some countries in Eastern Europe.
China began to produce 2-naphthol in 1957. Since 1980s, as developed countries stopped production one after another, China has become the main supplier of 2-naphthol.
Since 1990, the 2-naphthol market has experienced great ups and downs. In recent years, the annual output of 8-100 thousand tons has been maintained, and the export has also maintained a large growth, with the export of 8,227 tons in 2005, 15,924 tons in 2006, and 15,307 tons from January to October 2007.
The consumption of 2- naphthol in China is about 60% of dye intermediates, 20% of rubber additives, 10% of dyes and pigments, and 10% of others.
As the demand for dyes and pigments increases, so will the demand for 2-naphthol.
Improving the production process, saving energy and reducing consumption, reducing three wastes or developing new cleaning process has become an important direction for the continuous and healthy development of 2-naphthol production industry.
Second, the application in the dye and pigment industry
Dye and pigment intermediates are the largest consumption areas of 2-naphthol in China. The main reason is that the production of dye intermediates has been undergoing worldwide transfer. For example, 2, 3 acids, J acid, γ acid, R acid and chromophenol AS are all important intermediate exports in China, accounting for more than half of the total domestic output.
In addition to the synthesis of dyestuff and pigment intermediates, 2-naphthol can also be used as an azo part, and diazo compounds to produce dyestuff 1,2, 3 acids.
2, 3 acidification scientific name: 2-hydroxy-3-naphthic acid, its synthesis method is [1] : 2-naphthol and sodium hydroxide reaction, decompressed dehydration, get 2-naphthol sodium, and then reaction with CO2 to get 2-naphthol and 2, 3 sodium salt, remove 2-naphthol, acidification, get 2, 3 acid.
At present, the main synthesis methods are solid phase method and solvent method, and solvent method is the general trend of development.
Lake pigments with 2,3 acids as coupling components are synthesized by first making diazo components into diazo salts, coupled with 2,3 acids, and then using alkali metal and alkali earth metal salts can be converted into insoluble lake dyes.
The main chromatogram of 2,3 acid lake pigments is red light.
For example: C.I. Pigment Red 57:1, C.I. Pigment Red 48:1, etc.
2, 3 acids are widely used in the synthesis of chromophenol series of ice-dyed dyes. In the Dye Index of 1992, 28 chromophenols were synthesized by 2, 3 acids.
Color phenol AS series of coupling components of azo pigment, synthetic methods of this kind of paint is made from diazo component diazonium salt first, and the color of phenol coupling AS a series of derivatives, such AS the diazo components only contain alkyl aromatic ring, halogen, nitrocellulose, alkoxy groups, such AS the ordinary color resulting from the reaction of phenol AS a series of azo dye for coupled components,
For example, the aromatic ring of diazo components also contains sulfonic acid groups, and chromophenol AS series derivatives, and then the salt of alkali and alkali earth metals can be converted into insoluble lake dyes.
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