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Production process of fluorescent whitening agent OB-1

A fluorescent whitening agent, OB-1 technology, applied in the direction of organic chemistry, can solve the problems of low yield and pollute the environment, and achieve the effect of high yield and short synthesis steps

Active Publication Date: 2021-03-09
HEBEI XINGYU CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003]4,4'-bis(benzoxazol-2-yl)stilbene (i.e. optical brightener OB-1) is a stilbene benzo A kind of oxazole fluorescent whitening agent, which has excellent whitening effect and thermal stability, and is an important species of oxazole fluorescent whitening agent. Its current synthesis route is mainly based on stilbene 4,4- Diformic acid and o-aminophenol are prepared by cyclocondensation. Stilbene derivatives can undergo coupling reactions under the catalysis of Pd / C to generate stilbene compounds. Stilbene chlorobenzene derivatives are synthesized by Witting-Homer reaction , the chlorination reaction requires excessive hydrochloric acid, ZnCl2, etc., the yield is low, and at the same time, toxic substances such as dichloromethyl ether are produced, which seriously pollute the environment

Method used

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  • Production process of fluorescent whitening agent OB-1

Examples

Experimental program
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Effect test

Embodiment 1

[0038] A kind of production technology of optical brightener OB-1, specifically comprises the following steps:

[0039] Step 1, condensation: p-toluic acid and o-aminophenol undergo a condensation reaction to generate 4-methylphenylbenzoxazole;

[0040] According to the molar ratio of o-aminophenol to p-toluic acid 1:1.43, and the mass ratio of o-aminophenol to solvent oil 1:3.5, first add 1500Kg of solvent oil into the beating kettle, start stirring, and then put p-toluene into the beating kettle 885Kg of formic acid and 500Kg of o-aminophenol are stirred evenly and then pumped into the condensation kettle through the dump pump; 99.99% nitrogen gas is introduced into the condensation kettle to prevent the material from being oxidized, and then the temperature of the material in the condensation kettle is raised to above 120°C to start condensation dehydration Reaction, reaction for 20 hours, the reaction temperature rises to 220°C, and the reaction is completed to obtain a 4-...

Embodiment 2

[0057] A kind of production technology of optical brightener OB-1, specifically comprises the following steps:

[0058] Step 1, condensation: p-toluic acid and o-aminophenol undergo a condensation reaction to generate 4-methylphenylbenzoxazole;

[0059] According to the molar ratio of o-aminophenol to p-toluic acid 1:1.23, and the mass ratio of o-aminophenol to solvent oil 1:2.5, first add 1250Kg of solvent oil into the beating kettle, start stirring, and then put p-toluene into the beating kettle 761Kg of formic acid and 500Kg of o-aminophenol are stirred evenly and pumped into the condensation kettle through the dump pump; 99.99% nitrogen gas is introduced into the condensation kettle to prevent the material from being oxidized, and then the temperature of the material in the condensation kettle is raised to above 110°C to start condensation dehydration Reaction, reaction for 22 hours, the reaction temperature rose to 210°C, and the reaction was completed to obtain a 4-methy...

Embodiment 3

[0076] A kind of production technology of optical brightener OB-1, specifically comprises the following steps:

[0077] Step 1, condensation: p-toluic acid and o-aminophenol undergo a condensation reaction to generate 4-methylphenylbenzoxazole;

[0078] According to the molar ratio of o-aminophenol to p-toluic acid 1:1.63, and the mass ratio of o-aminophenol to solvent oil 1:3, first add 1750Kg of solvent oil into the beating kettle, start stirring, and then put p-toluene into the beating kettle 1009Kg of formic acid and 500Kg of o-aminophenol are stirred evenly and pumped into the condensation kettle through the dump pump; 99.99% nitrogen gas is introduced into the condensation kettle to prevent the material from being oxidized, and then the temperature of the material in the condensation kettle is raised to above 130°C to start condensation dehydration Reaction, reaction for 18 hours, the reaction temperature rose to 230°C, and the reaction was completed to obtain a 4-methyl...

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Abstract

The invention relates to a production process of a fluorescent whitening agent OB-1. The production process specifically comprises the following steps: 1, carrying out condensation reaction on p-toluic acid and o-aminophenol to generate 4-methyl phenyl benzoxazole; 2, carrying out distillation treatment after the condensation reaction is finished, and collecting a main fraction 4-methyl intermediate; 3, adding methanol into the main fraction, keeping the temperature at 60 DEG C for 6 hours, cooling to 10 DEG C, centrifugally filtering, drying, and transferring into a vulcanization synthesis kettle; 4, carrying out a vulcanization synthesis reaction on the 4-methyl intermediate to generate OB-1, rinsing with xylene, repeatedly washing with xylene, and drying the xylene by distillation to obtain a dried OB-1 crude product; 5, adding trichlorobenzene, the OB-1 crude product and activated carbon into a refining kettle to refine OB-1; and 6, pulping and washing OB-1 with methanol, carryingout centrifugal separation, and drying a filtering cake to obtain the OB-1 product. The method is environmentally friendly, safe and high in yield.

Description

technical field [0001] The invention belongs to the field of fluorescent whitening agent preparation, and in particular relates to a production process of fluorescent whitening agent OB-1. Background technique [0002] Fluorescent whitening agent can improve the whiteness and luster of the substance. It is a whitening agent product with good heat resistance. It not only has high decomposition temperature, good whiteness, and small dosage, but also has good compatibility with additives in thermoplastics. Compatibility, mainly used for whitening of polyester resin, polyester fiber and ordinary fiber; [0003] 4,4'-bis(benzoxazol-2-yl)stilbene (that is, fluorescent whitening agent OB-1) is a kind of stilbene benzoxazole fluorescent whitening agent, which has excellent brightening Whitening effect and thermal stability, it is an important variety of oxazole fluorescent whitening agent. Its current synthetic route is mainly prepared by cyclization condensation of stilbene 4,4-di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D263/57
CPCC07D263/57
Inventor 马学文葛德三刘文平李任泽
Owner HEBEI XINGYU CHEM
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