Method for producing naphthalene water reducing agent

The technology of a naphthalene-based water reducing agent and a production method, which is applied in the field of building materials, can solve the problems of high operational risk, unfavorable environment, high toxicity of benzene, etc., and achieves low-cost and easy-to-obtain raw materials, safe reaction conditions and high reaction yield. Effect

Inactive Publication Date: 2012-06-20
上海新浦特种助剂有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, in the sulfonation reaction of the first step, naphthalene and concentrated sulfuric acid generate 2-naphthalenesulfonic acid and water, and the generated water will dilute the concentrated sulfuric acid, thereby affecting the continuation of the reaction, reducing the sulfonation reaction rate and sulfonation conversion efficiency , in the prior art, either adopt benzene to carry water to remove the water generated by the reaction, so that the reaction proceeds smoothly; or, feed sulfur trioxide into the reactor so that the concentration of the concentrated sulfuric acid does not decrease; however, the benzene The toxicity is relatively high, which is unfavorable to the environment, and the post-treatment is cumbersome and costly; while the introduction of sulfur trioxide makes the reaction not mild enough, and the operation risk is relatively high

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Add 1mol of industrial naphthalene (boiling point 240~260℃) into the reactor, stir, heat to molten state, add 1.3mol of concentrated sulfuric acid (its concentration ≥98%), then add 0.046mol of anhydrous sodium sulfate, and then add 160~ React at 165°C for 2 to 3 hours; add an appropriate amount of water to the reactor, control the acidity to be 27 to 29%, stop hydrolysis in about 30 minutes, and obtain 2-naphthalenesulfonic acid through post-treatment; add to the 2-naphthalenesulfonic acid Add 0.7mol of formaldehyde; react at 100-110° C. for 3-4 hours, then add NaOH, control the pH to be 7-9, filter to remove excess sodium sulfate, and obtain the naphthalene-based liquid water reducing agent of the present invention.

Embodiment 2

[0025] Add 0.68mol of industrial naphthalene (boiling point 240~260℃) into the reactor, stir, heat to molten state, add 0.052mol of anhydrous sodium sulfate to it, then add 1.0mol of concentrated sulfuric acid (its concentration ≥98%), Stir, react at 160~165 ° C for 2~3 hours; add an appropriate amount of water to the reactor, control the acidity to be 27~29%, stop acidolysis in about 30 minutes, and obtain 2-naphthalenesulfonic acid through post-treatment; -Add 1mol formaldehyde to naphthalenesulfonic acid; react at 100~110°C for 3~4 hours, then add NaOH, control the pH value to be 7~9, filter to remove excess sodium sulfate, and obtain the naphthalene-based liquid water reducer of the present invention .

Embodiment 3

[0027] 1mol of industrial naphthalene (boiling point 240~260℃) was added to the reactor, stirred and heated to a molten state. At the same time, 0.089mol of anhydrous sodium sulfate and 1.4mol of concentrated sulfuric acid (its concentration ≥98%) were added to the reactor. 160~165 ℃ of reaction for 2~3 hours; add an appropriate amount of water to the reactor, control the acidity to be 27~29%, stop acidolysis in about 30 minutes, and obtain 2-naphthalenesulfonic acid through post-treatment; Add 1.1mol formaldehyde to sulfonic acid; react at 100~110℃ for 3~4 hours, then add CaO / Ca(OH) 2 , the pH value is controlled to be 7 to 9, and excess sodium sulfate and calcium sulfate are removed by filtration to obtain the naphthalene-based liquid water reducing agent of the present invention.

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Abstract

The invention discloses a method for producing naphthalene water reducing agent, which comprises the following steps: (1) sulphonating: adding naphthalene, concentrated sulfuric acid and anhydrous sodium sulfate while stirring into a reactor, and making the materials react at 160-165 DEG C for 2-3 hours, wherein the molar ratio of the naphthalene to the concentrated sulfuric acid is 1:1.3 to 1.5, and the addition amount of the anhydrous sodium sulfate is 5-9% by the weight percent of the concentrated sulfuric acid; (2) hydrolyzing: adding water to the reaction solution to control the acidity at 27-29%, and stirring for 30 minutes; (3) condensing: adding formaldehyde to the reaction solution, and making the formaldehyde react with the reaction solution at 100-110 DEG C for 3-4 hours, wherein the molar ratio of the formaldehyde to naphthalene sulfonate is 0.7 to 1.5:1; (4) neutralizing: adding alkali to the reaction solution to neutralize the reaction solution, and controlling the pH value at 7-9; and (5) filtering: filtering to remove unnecessary sulfate to obtain the naphthalene water reducing agent. The method for producing the naphthalene water reducing agent by adopting one pot has the advantages of cheap and readily available raw materials, safe and mile reaction condition, simple process, safe operation, high reaction yield and low cost and can be used for industrial production on a large scale.

Description

technical field [0001] The invention relates to a building material, in particular to a method for producing a naphthalene-based water reducing agent for building. Background technique [0002] Naphthalene series superplasticizer is the largest polycondensation type superplasticizer in my country, and it is also one of the earliest popular cement admixtures in China. With the development and development of the market, the competition is becoming increasingly fierce. [0003] The existing classical production process is: 1) sulfonation reaction of industrial naphthalene and concentrated sulfuric acid; 2) hydrolysis; 3) condensation; 4) neutralization; 5) filtration. Wherein, in the sulfonation reaction of the first step, naphthalene and concentrated sulfuric acid generate 2-naphthalenesulfonic acid and water, and the generated water will dilute the concentrated sulfuric acid, thereby affecting the continuation of the reaction, reducing the sulfonation reaction rate and the s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B24/22C04B103/30
Inventor 苏莹王德林杨杰
Owner 上海新浦特种助剂有限公司
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