Preparation method of low-ash fiber-grade polyvinyl alcohol

A polyvinyl alcohol and fiber-grade technology is applied in the field of preparation of low-ash fiber-grade polyvinyl alcohol, which can solve the problems of high chemical oxygen demand of sewage, inability to discharge directly, waste of resources, etc., so as to reduce usage and improve alcoholysis. degree, the effect of ensuring product quality

Active Publication Date: 2021-02-09
INNER MONGOLIA MENGWEI TECH CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When used in the spinning field, sodium acetate must be washed away with water before use. The amount of sodium acetate directly affects the loss of PVA during the washing process. At the same time, the washing process produces a large amount of sewage containing PVA and sodium acetate. Sewage chemistry Oxygen demand COD is high, it cannot be discharged directly, and secondary treatment is required, resulting in waste of resources

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Embodiment 1, preparation fiber grade PVA17-99 product

[0017] According to the alkali molar ratio is 0.018, the methanol solution of polyvinyl acetate with a polyvinyl acetate mass concentration of 33% and the methanol solution of sodium hydroxide with a sodium hydroxide concentration of 25g / L are mixed uniformly, and then heated at a temperature of 39°C Alcoholysis for 36 minutes;

[0018] The obtained product is dried after pulverization and solid-liquid separation; during the drying process, the mixed solution of water and methanol is uniformly sprayed on the material (the volume ratio of water and methanol is 1:1), and the spraying amount of the mixed solution accounts for 0.03% of the theoretical yield of vinyl alcohol; after drying, fiber-grade polyvinyl alcohol is obtained.

[0019] After testing, the alcoholysis degree of the obtained PVA is 99.78%, and the sodium acetate content is 1.2%.

Embodiment 2

[0020] Embodiment 2, preparation fiber grade PVA17-99 product

[0021] According to the alkali molar ratio is 0.017, the methanol solution of polyvinyl acetate with a polyvinyl acetate mass concentration of 32% and the methanol solution of sodium hydroxide with a sodium hydroxide concentration of 20g / L are mixed uniformly, and then heated at a temperature of 39°C Alcoholysis for 36 minutes;

[0022] The obtained product is dried after pulverization and solid-liquid separation; during the drying process, the mixed solution of water and methanol is uniformly sprayed on the material (the volume ratio of water and methanol is 1:1), and the spraying amount of the mixed solution accounts for 0.04% of the theoretical yield of vinyl alcohol; after drying, fiber-grade polyvinyl alcohol is obtained.

[0023] After testing, the degree of alcoholysis of the obtained PVA is 99.81%, and the content of sodium acetate is 1.15%.

Embodiment 3

[0024] Embodiment 3, preparation fiber grade PVA17-99 product

[0025] According to the alkali molar ratio is 0.016, the methanol solution of polyvinyl acetate with a polyvinyl acetate mass concentration of 31% and the methanol solution of sodium hydroxide with a sodium hydroxide concentration of 20g / L are mixed uniformly, and then heated at a temperature of 39°C Alcoholysis for 36 minutes;

[0026] The obtained product is dried after pulverization and solid-liquid separation; during the drying process, the mixed solution of water and methanol is uniformly sprayed on the material (the volume ratio of water and methanol is 1:1), and the spraying amount of the mixed solution accounts for 0.05% of the theoretical yield of vinyl alcohol; after drying, fiber-grade polyvinyl alcohol is obtained.

[0027] After testing, the alcoholysis degree of the obtained PVA is 99.83%, and the sodium acetate content is 1.1%.

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Abstract

The invention discloses a preparation method of low-ash-content fiber-grade polyvinyl alcohol. According to the method, on the basis of the existing technique, the addition amount of catalyst alkali in an alkali catalytic alcoholysis unit is reduced, and a water-methanol mixed solution is additionally introduced into a drying unit. By changing the production process, the content of sodium acetatein the fiber-grade polyvinyl alcohol is reduced to 1.1-1.2%; besides, the use amount of the base catalyst is reduced while the product quality is ensured, the production cost is reduced, and the alcoholysis degree of PVA is improved.

Description

technical field [0001] The invention belongs to the technical field of organic chemical production, and in particular relates to a method for preparing low-ash fiber grade polyvinyl alcohol. Background technique [0002] Polyvinyl alcohol (PVA for short) is a widely used water-soluble polymer and an important chemical intermediate product. It has excellent bonding strength, very good film-forming properties, and very good chemical resistance. Therefore, in addition to being used as fiber raw materials, it is also widely used in the production of coatings, adhesives, paper product processing agents, textile pulp, emulsifiers, dispersants, films and other products, with a wide range of applications. Studies have shown that microorganisms that can degrade PVA widely exist in the natural environment. Therefore, the production and use of PVA and its derivatives meet the requirements of today's environmental protection, and have very broad application prospects. [0003] The pr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F8/00C08F118/08
CPCC08F8/00C08F118/08
Inventor 吴四海孙广兵杨玮张明韩小龙刘德志李利李刚李健全龚健
Owner INNER MONGOLIA MENGWEI TECH CO LTD
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