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Method for preparing mononaphthalenesulfonic acid and sodium salt of mononaphthalenesulfonic acid

A technology of sodium naphthalene sulfonate and naphthalene sulfonic acid is applied in the field of preparation of naphthalene sulfonic acid and its sodium salt, which can solve the problems of high purity of 1-naphthol, difficult reaction control, and difficult separation of isomers, and achieves sulfonation The effect of stable reaction, saving solvent consumption and improving yield

Inactive Publication Date: 2007-05-09
江苏华达化工集团有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Overcome the shortcomings of the low-temperature sulfonation process using sulfuric acid as a sulfonating agent in the prior art, which are difficult to overcome, such as large amount of waste acid wastewater, difficult separation of isomers, and poor operability; overcome the disadvantages of the chlorosulfonic acid sulfonation process in the prior art Stable, poor operability, the shortcoming that reaction is difficult to control, and the 1-naphthalenesulfonic acid and / or 1-naphthalenesulfonic acid sodium salt that the present invention prepares contains fewer isomers, and the 1-naphthalenesulfonic acid sodium salt that obtains after sulfonation alkali fusion Naphthol has high purity and contains less impurity 2-naphthol

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Embodiment 1 produces 1-naphthalenesulfonic acid according to the present invention.

[0029] Add 100 grams (0.78 moles) of refined naphthalene and 380 grams (2.52 moles) of o-nitroethylbenzene into a 500 mL ground-necked four-neck flask with stirring, place the flask in an ice-salt bath for cooling, and start the stirrer to make the refined naphthalene completely After dissolution, 1 g of 1-naphthalenesulfonic acid seed crystals were added. 92 grams (0.79 moles) of chlorosulfonic acid were added to the dropping funnel, and placed on the feed port of the four-neck flask. Connect the flask to a water flushing pump and turn it on so that the inside of the flask is under negative pressure. When the temperature of the solution in the flask reaches 0°C, start to add chlorosulfonic acid dropwise, and finish dropping within 1-2 hours. During the dropping process, the temperature is kept between -2-3°C by controlling the dropping rate of chlorosulfonic acid. After the dropwi...

Embodiment 2

[0033] Embodiment 2 prepares 1-naphthalenesulfonic acid sodium salt with the obtained-naphthalenesulfonic acid of embodiment 1.

[0034] In the flask, the 1-naphthalenesulfonic acid filter cake in Example 1 is added into the prepared concentration to dissolve in 400 grams of 10% NaOH solution, add the organic phase obtained by the filtrate layering after the above-mentioned sulfonated liquid is filtered, and stir Raise the temperature to 90°C and maintain at 90°C to 95°C for 10 minutes to carry out the neutralization reaction, and pour the neutralization solution into a 1000mL separatory funnel.

[0035] The neutralization solution in the separatory funnel was kept at 90°C, and separated after standing for 10 minutes; the lower layer was 1-naphthalenesulfonic acid sodium salt solution, which was divided into a 1000mL beaker; the upper layer was an organic layer, which was divided into a beaker, and 25 g anhydrous Na 2 SO 4 Carry out dehydration treatment, reclaim 367 grams o...

Embodiment 3

[0038] Other conditions of embodiment 3 are identical with embodiment 1, difference is, in embodiment 3, dropwise add 95.5 grams (0.82 mole) chlorosulfonic acid and carry out sulfonation reaction, in dropwise process and during reaction maintenance, control temperature Between 3-8°C. Obtain 162 grams of 1-naphthalenesulfonic acid filter cake (containing a small amount of solvent).

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Abstract

This invention discloses a method for synthesizing 1-naphthalene sulfonic acid and / or sodium 1-naphthalene sulfonate. The method comprises: (1) dissolving naphthalene in solvent, adding appropriate 1-naphthalene sulfonic acid seed crystals, cooling to 0 minus or plus 5 deg.C, stirring, dropping chlorosulfonic acid within 1-2 h, and keeping at -2-8 deg.C for 1.5-3 h; (2) cooling to 0 minus or plus 2 deg.C, and filtering to obtain the filter cake of 1-naphthalene sulfonic acid; (3) washing the filtrate with water, phase-separating to obtain the solvent and water scrubbing acid (for producing high-performance naphthalene water reducer); (4) neutralizing 1-naphthalene sulfonic acid and the solvent with 5-15% NaOH, keeping at 90 minus or plus 5 deg.C for 10-30 min, phase-separating the neutralization solution to obtain sodium 1-naphthalene sulfonate aqueous solution, cooling to lower than 35 deg.C, crystallizing, filtering to obtain the filter cake of sodium 1-naphthalene sulfonate, and utilizing the filtrate to prepare NaOH solution. The method has such advantages as high sulfonation selectivity, low product isomer content, easy operation and no wastewater.

Description

technical field [0001] The invention relates to a preparation method of naphthalenesulfonic acid and its sodium salt, in particular to a preparation method of 1-naphthalenesulfonic acid and 1-naphthalenesulfonic acid sodium salt. Background technique [0002] 1-Naphthalenesulfonic acid or 1-naphthalenesulfonic acid sodium salt is mainly used to prepare 1-naphthol. Generally, the raw material naphthalene is sulfonated to obtain 1-naphthalenesulfonic acid, and then neutralized and salted out to obtain 1-naphthalene Sulfonic acid sodium salt; 1-naphthalene sulfonic acid sodium salt is obtained by alkali fusion and acidification to 1-naphthol. The existing preparation methods mainly include low-temperature sulfonation method and chlorosulfonic acid sulfonation method according to the sulfonating agent used. [0003] The low-temperature sulfonation method uses naphthalene as the raw material, uses 98% sulfuric acid as the sulfonating agent, and the sulfonation reaction temperatu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C309/35C07C303/08C07C303/32
Inventor 李琪章苏建华徐光辉文宁锋
Owner 江苏华达化工集团有限公司
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