Preparation method of polyvinyl alcohol resin high in alcoholysis degree

A technology of polyvinyl alcohol resin and high degree of alcoholysis, which is applied in the field of production of polyvinyl alcohol resin, can solve problems such as toxicity, products not meeting the requirements of medical grade, and affecting the physical, chemical and mechanical properties of polymer emulsions. The effect of increasing production and increasing conversion rate

Inactive Publication Date: 2020-01-31
ZHENDE MEDICAL CO LTD
View PDF6 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The existing process is to mix PVAc (polyvinyl acetate) and methanol, put it into the alcoholysis tank, add methanol and sodium hydroxide, pass through two powder machines, and then transport to the press to recover excess methanol, transport and dry , discharge to obtain PVA; but such PVA is only chemical grade, in the production process of polyvinyl acetate produced from vinyl acetate, affected by conditions such as production raw materials, operating technology, production equipment, personnel technical level, the production of vinyl acetate monomer The conversion rate cannot reach 100%, so a small amount of unpolymerized monomer-vinyl acetate remains in the polymer
Polymer residual monomers, on the one hand, affect the physical, chemical and mechanical properties of polymer emulsions; on the other hand, they will also bring environmental and health problems. Vinyl acetate residual monomers have certain toxicity; the products obtained by traditional processes reach Less than medical grade requirements, the present invention solves such problems

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of polyvinyl alcohol resin high in alcoholysis degree
  • Preparation method of polyvinyl alcohol resin high in alcoholysis degree
  • Preparation method of polyvinyl alcohol resin high in alcoholysis degree

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0030] Such as figure 1 Shown, a kind of preparation method of high degree of alcoholysis polyvinyl alcohol resin comprises the steps:

[0031] The first step: preparation of PVAc / methanol solution.

[0032] Add methanol solution into the electrolytic alcoholysis kettle, slowly add PVAc particles under stirring, heat to 55°C to fully dissolve, and obtain PVAc-methanol solution; the weight ratio of PVAc / methanol solution is 20-22 / 78-80 , as a preference, the weight ratio of PVAc / methanol solution is 22 / 78.

[0033] The second step: the preparation of alkali-methanol solution,

[0034] The base was dissolved in methanol solution. The type of base is not limited, as long as it can provide hydroxide ions, it can be used in the present invention. The base is NaOH, and the weight ratio of NaOH-methanol solution to PVAc is 12%.

[0035] The third step: put polymethylsiloxane into the electrolytic alcoholysis ax with PVAc / methanol solution, and then pass in direct current under th...

Embodiment 1

[0054] first step:

[0055] Add 60 kg of methanol solution into the electrolytic alcoholysis kettle, slowly add 240 kg of PVAc particles under stirring, and heat to 55°C to fully dissolve the PVAc particles to obtain a PVAc-methanol solution; the ratio of PVAc / methanol solution is 20 / 80 .

[0056] Step two:

[0057] Another container was used to weigh 28.8 kg of NaOH solid and dissolve it in 160 kg of methanol solution.

[0058] The third step: put 2.16 kilograms of polymethylsiloxane into the electrolytic reactor of the first step, and then put the product obtained in the second step into the electrolytic reactor at 200 rpm. Under the condition of keeping the temperature at 45-48°C, direct current is supplied, and the direct current voltage is 20 volts. The positive and negative poles are located on both sides of the electrolytic alcoholysis kettle. Stir for 33 minutes at a speed of 200 revolutions per minute.

[0059] Step 4: Stop stirring, heat to the range of 58-65°C, ...

Embodiment 2

[0062] first step:

[0063] Add 66 kg of methanol solution into the electrolytic alcoholysis kettle, slowly add 234 kg of PVAc particles under stirring, and heat to 55°C to fully dissolve the PVAc particles to obtain a PVAc-methanol solution; the ratio of PVAc / methanol solution is 22 / 78 .

[0064] Step two:

[0065] Another container was used to weigh 28.08 kg of NaOH solid and dissolve it in 153 kg of methanol solution.

[0066] The third step: put 2.106 kg of polymethylsiloxane into the first step electrolytic reaction kettle, and then put the product obtained in the second step into the electrolytic reaction kettle at 200 rpm. Under the condition of keeping the temperature at 45-48°C, direct current is supplied, and the direct current voltage is 20 volts. The positive and negative poles are located on both sides of the electrolytic alcoholysis kettle. Stir for 33 minutes at a speed of 200 revolutions per minute.

[0067] Step 4: Stop stirring, heat to the range of 58-65...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
volatile matteraaaaaaaaaa
Login to view more

Abstract

The invention discloses a preparation method of high-alcoholysis-degree polyvinyl alcohol resin. The preparation method comprises the following steps: adding methanol into an electrolytic alcoholysiskettle, slowly adding PVAc while stirring, and heating to dissolve to obtain a PVAc/methanol solution; dissolving NaOH in methanol to obtain a NaOH-methanol solution; adding polymethylsiloxane into the electrolytic alcoholysis kettle containing the PVAc/methanol solution, and then applying direct current at a temperature kept to be 45-48 DEG C; reducing the temperature of the PVAc/methanol solution to 28-32 DEG C, and adding the NaOH-methanol solution into the electrolytic alcoholysis kettle for reaction; passing an obtained product through a pulverizer and a squeezer, and drying and discharging to obtain medical-grade polyvinyl alcohol resin. According to the preparation method, monomer residue is reduced, so that energy saving and emission reduction are realized, and the influence of monomers on the chemical and mechanical properties of polyvinyl acetate and polyvinyl alcohol is reduced, so that the product can meet the medical-grade requirements.

Description

technical field [0001] The invention relates to the field of producing polyvinyl alcohol resin, in particular to a preparation method of polyvinyl alcohol resin with high degree of alcoholysis. Background technique [0002] Polyvinyl alcohol is a hydrolysis product of polyvinyl acetate, which contains a large number of hydroxyl groups and is soluble in water. Has good biocompatibility and anticoagulation. Medical polyvinyl alcohol resin requires non-toxic, pure, non-allergic, non-carcinogenic, non-thrombogenic, non-destructive blood cells and changes in plasma protein components. Polyvinyl alcohol is the only water-soluble and non-toxic high polymer that has been found so far. Polyvinyl alcohol itself is non-toxic, but due to the monomer residues, Auxiliary residue, -OCOCH 3 Factors such as side effects and production environment cause some indicators to fail to meet medical requirements. [0003] Polyvinyl alcohol is water-soluble, but when the degree of polymerization ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C08F18/08C08F8/12C08F2/52
CPCC08F2/52C08F8/12C08F18/08
Inventor 鲁建国
Owner ZHENDE MEDICAL CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap