CN102863567B - Preparation method of polyvinyl alcohol through low-alkali method - Google Patents
Preparation method of polyvinyl alcohol through low-alkali method Download PDFInfo
- Publication number
- CN102863567B CN102863567B CN201110189073.6A CN201110189073A CN102863567B CN 102863567 B CN102863567 B CN 102863567B CN 201110189073 A CN201110189073 A CN 201110189073A CN 102863567 B CN102863567 B CN 102863567B
- Authority
- CN
- China
- Prior art keywords
- washing
- polyvinyl alcohol
- solid
- alcohol
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The invention provides a preparation method of polyvinyl alcohol through a low-alkali method. The preparation method comprises an aftertreatment step and is characterized in that a washing step is operated in the aftertreatment step. The preparation method of the polyvinyl alcohol through the low-alkali method improves quality of the polyvinyl alcohol, mass percent content of methyl alcohol contained by the polyvinyl alcohol is lower than 1.0%, content of impurities such as acetic acid, methyl acetate and the like is reduced, and influence on the environment of the polyvinyl alcohol manufactured by the method in a using process is reduced. Simultaneously, the preparation method is free of environment pollution, low in production energy consumption and low in cost.
Description
Technical field
The present invention relates to the production technical field of polyvinyl alcohol (PVA), particularly a kind of low alkaline process prepares the method for polyvinyl alcohol.
Background technology
Polyvinyl alcohol (PVA) is obtained through alkali catalyzed alcoholysis by polyvinyl acetate (PVA), and wherein used alcohol is generally methyl alcohol, obtains polyvinyl alcohol through alcoholysis reaction, and produce the by product such as methyl acetate and sodium-acetate.Polyvinyl alcohol solidifies and obtains solid product in alcohol and methyl acetate, after aftertreatment (pulverizing, squeezing, drying etc.) step process, obtain product.Wherein the drying of polyvinyl alcohol is the drying machine inner drying at about 100 DEG C, in this process, major part methyl alcohol and by-product acetic acid methyl esters can be removed by steaming, but because environment solvent strength is high, and partial solvent is wrapped in polyvinyl alcohol inside and not easily removes completely, therefore in the polyvinyl alcohol produced of low alkaline process, methanol content generally has about 2%.In polyvinyl alcohol product use procedure, being wrapped in inner methyl alcohol will overflow, and has influence on the use of downstream user.
What in polyvinyl alcohol, the method for purification of inorganic salt was conventional is water-soluble alcohol extracting liberation method, its step: first fully dissolved in water by polyvinyl alcohol resin, and salt constituents wherein is also dissolved in the water; Because polyvinyl alcohol resin is insoluble in ethanol, after adding enough ethanol, can separate out immediately; Stir, filter, part salt, methyl alcohol, ritalin are taken away by solution again, and drying, pulverizing obtain finished product again to separate out solid polyethylene alcohol resin.This method can cause polyvinyl alcohol resin lose large, ethanol consumption large, and introduces new impure alcohol, cost and pollute larger.And the product obtained is in block, density is large, and structure is hard, can produce many grits during pulverizing.
The patent No. is describe water vapor two-step approach purification polyvinyl alcohol resin in CN1074424C, its step: containing water vapor and in the atmosphere of vapour content 20% ~ 80%, carry out the stirring of solid polyethylene alcohol resin, remove organic solvent residual by the diluent gas such as water vapor and nitrogen.This method needs to consume a large amount of steam and diluent gas, and cost is high, needs the drying treatment of carrying out annex to remove moisture simultaneously.
The method with aqueous ethanolic solution purify poly (vinyl alcohol) resin is described, its step: first added by polyvinyl alcohol resin in the mixed solvent of ethanol water and stir in Chinese patent 200810151479.3; Add ethanol or aqueous ethanol again, polyvinyl alcohol resin is separated out; Finally be separated drying.This method reduce product methanol content, but introduce new ethanol, the drying treatment removing moisture simultaneously needing to carry out adding, cost are high.
Summary of the invention
The object of the present invention is to provide a kind of low alkaline process to prepare the method for polyvinyl alcohol, the inventive method industrially can realize the polyvinyl alcohol of the low methanol content of low cost production.
The object of the present invention is achieved like this:
Low alkaline process prepares a method for polyvinyl alcohol, comprises post-processing step, it is characterized in that: describedly in post-processing step, increase water-washing step.
Above-mentioned post-processing step comprise polyvinylalcohol solids pulverized, squeeze, drying and other steps.
In order to reduce the load of drying treatment, thus reduce drying cost further, above-mentioned water-washing step carries out before squeezing after being the pulverizing in aftertreatment.
In order to reduce the methanol content of polyvinyl alcohol further, the temperature of above-mentioned washing is 5 ~ 25 DEG C, and washing time is 3 ~ 15 minutes; Be preferably washing temperature 10 ~ 20 DEG C, washing time 5 ~ 15 minutes.
In order to reduce environmental pollution further, above-mentioned water-washing step is separated solid-liquid after being also included in washing, and after being separated, methyl alcohol, washing water recycle and reuse are reclaimed in liquid phase rectifying, carry out drying again to solid polycondensation vinyl alcohol resin after squeezing.
Specifically, a kind of low alkaline process prepares the method for polyvinyl alcohol:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. by solid product through pulverizing, solid-liquid separation after rinse bath carries out washing and wash, solid phase obtains polyvinyl alcohol product through pressing and drying again; Wherein washing temperature is 10 ~ 20 DEG C, and washing time is 5 ~ 15 minutes, and the solid-liquid separation after described washing is that methyl alcohol, simultaneously washing water recycling use are reclaimed in liquid phase rectifying.
Beneficial effect of the present invention
The method of the present invention's low alkaline process production polyvinyl alcohol improves the quality of final polyvinyl alcohol, wherein the mass percentage of contained methyl alcohol is lower than 1.0%, also reduce the content of the impurity such as the sodium-acetate contained by it, ritalin, decrease the impact of the polyvinyl alcohol environment in use that the inventive method obtains; Simultaneously the inventive method environmentally safe, production energy consumption is low, cost is low.
Embodiment
Below by embodiment, the present invention is specifically described; what be necessary to herein means out is that following examples are only used to further illustrate the present invention; can not be interpreted as limiting the scope of the invention, person skilled in art can make some nonessential improvement and adjustment according to the invention described above content to the present invention.
embodiment 1
A kind of low alkaline process prepares the method for polyvinyl alcohol:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. prepare the water solvent of 15 DEG C and stir, polyvinyl alcohol resin after pulverizing directly is added rinse bath, stir 10 minutes, make the methyl alcohol in polyvinyl alcohol resin soluble in water, then solid-liquid separation is carried out, methyl alcohol, simultaneously washing water recycling use are reclaimed in liquid phase rectifying, and the solid polycondensation vinyl alcohol resin obtained carries out squeezing, dry, dry qualified after obtain polyvinyl alcohol resin product.
embodiment 2
A kind of low alkaline process prepares the method for polyvinyl alcohol:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. prepare the water solvent of 16 DEG C and stir, polyvinyl alcohol resin after pulverizing directly is added rinse bath, stir 12 minutes, make the methyl alcohol in polyvinyl alcohol resin soluble in water, then solid-liquid separation is carried out, methyl alcohol, simultaneously washing water recycling use are reclaimed in liquid phase rectifying, and the solid polycondensation vinyl alcohol resin obtained carries out squeezing, dry, dry qualified after obtain polyvinyl alcohol resin product.
embodiment 3
A kind of low alkaline process prepares the method for polyvinyl alcohol:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. prepare the water solvent of 18 DEG C and stir, polyvinyl alcohol resin after pulverizing, squeezing directly is added rinse bath, stir 6 minutes, make the methyl alcohol in polyvinyl alcohol resin soluble in water, then solid-liquid separation is carried out, the solid polycondensation vinyl alcohol resin obtained carries out drying, and obtain polyvinyl alcohol resin product after drying is qualified, the content of its methyl alcohol is 0.20%.
embodiment 4
A kind of low alkaline process prepares the method for polyvinyl alcohol:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. prepare the water solvent of 5 DEG C and stir, polyvinyl alcohol resin after pulverizing directly is added rinse bath, stir 15 minutes, make the methyl alcohol in polyvinyl alcohol resin soluble in water, then carry out solid-liquid separation, methyl alcohol, simultaneously washing water recycling use are reclaimed in liquid phase rectifying, and the solid polycondensation vinyl alcohol resin obtained carries out squeezing, dry, obtain polyvinyl alcohol resin product after drying is qualified, the content of its methyl alcohol is 0.36%.
embodiment 5
A kind of low alkaline process prepares the method for polyvinyl alcohol:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. prepare the water solvent of 25 DEG C and stir, polyvinyl alcohol resin after pulverizing directly is added rinse bath, stir 3 minutes, make the methyl alcohol in polyvinyl alcohol resin soluble in water, then carry out solid-liquid separation, methyl alcohol, simultaneously washing water recycling use are reclaimed in liquid phase rectifying, and the solid polycondensation vinyl alcohol resin obtained carries out squeezing, dry, obtain polyvinyl alcohol resin product after drying is qualified, the content of its methyl alcohol is 0.4%.
embodiment 6
A kind of low alkaline process prepares the method for polyvinyl alcohol:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. prepare the water solvent of 13 DEG C and stir, polyvinyl alcohol resin after pulverizing directly is added rinse bath, stir 8 minutes, make the methyl alcohol in polyvinyl alcohol resin soluble in water, then solid-liquid separation is carried out, the solid polycondensation vinyl alcohol resin obtained carries out squeezing, dry, dry qualified after obtain polyvinyl alcohol resin product, the content of its methyl alcohol is 0.26%.
comparative example 1
?low alkaline process prepares the method for polyvinyl alcohol: polyvinyl acetate (PVA) and methyl alcohol, as a reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis; After solid product is pulverized, then carry out squeezing, carry out drying in 100 DEG C of drying machines and finally obtain polyvinyl alcohol resin.
The methanol content detected result of the polyvinyl alcohol resin that embodiment 1 is obtained sees the following form:
| Project | The polyvinyl alcohol resin that comparative example 1 is obtained | The polyvinyl alcohol resin that embodiment 1 is obtained |
| Methyl alcohol %(W) | 2.6％ | 0.30％ |
The methanol content detected result of the polyvinyl alcohol resin that embodiment 2 is obtained sees the following form:
| Project | The polyvinyl alcohol resin that comparative example 1 is obtained | The polyvinyl alcohol resin that embodiment 1 is obtained |
| Methyl alcohol %(W) | 2.58％ | 0.25％ |
Claims (5)
1. a low alkaline process prepares the method for polyvinyl alcohol, comprise post-processing step, it is characterized in that: described aftertreatment be comprise polyvinyl alcohol is pulverized, pressing and drying step, describedly in post-processing step, also carry out water-washing step, described washing is carried out before squeezing after being the pulverizing in aftertreatment; The temperature of described washing is 5 ~ 25 DEG C, and washing time is 3 ~ 15 minutes.
2. the method for claim 1, is characterized in that: the temperature of described washing is 10 ~ 20 DEG C, and washing time is 5 ~ 15 minutes.
3. the method for claim 1, is characterized in that: described water-washing step is separated solid-liquid after being also included in washing, and after being separated, methyl alcohol, washing water recycle and reuse are reclaimed in liquid phase rectifying, carry out drying again to solid polycondensation vinyl alcohol resin after squeezing.
4. method as claimed in claim 2, is characterized in that: described water-washing step is separated solid-liquid after being also included in washing, and after being separated, methyl alcohol, washing water recycle and reuse are reclaimed in liquid phase rectifying, carry out drying again to solid polycondensation vinyl alcohol resin after squeezing.
5. the method for claim 1, is characterized in that:
A. polyvinyl acetate (PVA) and methyl alcohol are as reaction raw materials, obtain solid polycondensation vinyl alcohol through alkali catalyzed alcoholysis;
B. by solid product through pulverizing, solid-liquid separation after rinse bath carries out washing and wash, solid phase obtains polyvinyl alcohol product through pressing and drying again; Wherein washing temperature is 10 ~ 20 DEG C, and washing time is 5 ~ 15 minutes, and the solid-liquid separation after described washing is that methyl alcohol, simultaneously washing water recycling use are reclaimed in liquid phase rectifying.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110189073.6A CN102863567B (en) | 2011-07-07 | 2011-07-07 | Preparation method of polyvinyl alcohol through low-alkali method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201110189073.6A CN102863567B (en) | 2011-07-07 | 2011-07-07 | Preparation method of polyvinyl alcohol through low-alkali method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102863567A CN102863567A (en) | 2013-01-09 |
| CN102863567B true CN102863567B (en) | 2014-12-24 |
Family
ID=47442718
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201110189073.6A Active CN102863567B (en) | 2011-07-07 | 2011-07-07 | Preparation method of polyvinyl alcohol through low-alkali method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102863567B (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106279479A (en) * | 2015-06-09 | 2017-01-04 | 中国石油化工集团公司 | A kind of method improving product polyvinyl alcohol alcoholysis degree |
| CN106757893A (en) * | 2015-11-19 | 2017-05-31 | 张家港市宏盛贸易有限公司 | Water-soluble fibre rinsing machine |
| CN106757892A (en) * | 2015-11-19 | 2017-05-31 | 张家港市宏盛贸易有限公司 | Water-soluble fibre rinsing machine |
| CN105906826A (en) * | 2016-04-27 | 2016-08-31 | 安徽皖维高新材料股份有限公司 | Continuous production method of differential polyvinyl alcohol films |
| CN106140717B (en) * | 2016-08-19 | 2019-01-01 | 安徽皖维高新材料股份有限公司 | A kind of polyvinyl alcohol resin rinsing bowl and quick water washing device |
| CN107151283B (en) * | 2017-05-27 | 2020-10-27 | 中国石油化工集团公司 | Preparation method of polyvinyl alcohol special for optical material |
| CN110028602B (en) * | 2019-04-28 | 2021-09-10 | 安徽皖维高新材料股份有限公司 | Method for reducing impurity content in industrial polyvinyl alcohol |
| CN110903415B (en) * | 2019-10-30 | 2023-02-24 | 中国石油化工股份有限公司 | Purification method of PVA (polyvinyl alcohol) raw material for optical film |
| CN117050011B (en) * | 2023-10-11 | 2024-01-23 | 湖南工程学院 | Method for synthesizing 2-methylquinoline by using vinyl acetate as raw material |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101092463A (en) * | 2006-12-18 | 2007-12-26 | 四川大学 | Method for preparing polyvinyl alcohol with low ash |
| CN102020735A (en) * | 2009-09-17 | 2011-04-20 | 中国石油化工集团公司 | Purification method of polyvinyl alcohol |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8350002B2 (en) * | 2009-10-07 | 2013-01-08 | The Nippon Synthetic Chemical Industry Co., Ltd. | Process for producing ethylene/vinyl alcohol copolymer |
-
2011
- 2011-07-07 CN CN201110189073.6A patent/CN102863567B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101092463A (en) * | 2006-12-18 | 2007-12-26 | 四川大学 | Method for preparing polyvinyl alcohol with low ash |
| CN102020735A (en) * | 2009-09-17 | 2011-04-20 | 中国石油化工集团公司 | Purification method of polyvinyl alcohol |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102863567A (en) | 2013-01-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102863567B (en) | Preparation method of polyvinyl alcohol through low-alkali method | |
| CN104877135A (en) | Washing and purifying method for polyphenylene sulfide resin production | |
| CN101905938A (en) | Method for recycling silicon chip cutting waste fluid | |
| CN105541556A (en) | Neopentyl glycol and sodium formate separating method | |
| CN105330539A (en) | Production process of dibutyl phthalate plasticizer | |
| CN102604151B (en) | Method for preparing environmental-friendly high-tenacity high-temperature reclaimed rubber | |
| CN104892971B (en) | Method for recycling solvent NMP in polyphenylene sulfide resin production process | |
| CN106495174B (en) | Attapulgite wet method bisgallic acid activation method | |
| CN103159602A (en) | After-treatment method of cinnamic aldehyde industrial synthesis | |
| CN103087147B (en) | Method for preparing silk feather protein powder for preparation of protein filament | |
| CN102180790B (en) | Method for removing water from ethyl acetate and butanone mixed solvent | |
| CN103319307A (en) | Method for preparing sodium soap | |
| CN103806086A (en) | Preparation method of basic magnesium carbonate whisker | |
| CN104877167B (en) | The method that adjuvant used lithium chloride recycles in polyphenylene sulfide resin production process | |
| CN103087201A (en) | Production technology for preparing hyperviscous industrial-grade cellulose glycolate by means of half aqueous medium process | |
| CN101475168B (en) | Method for washing active carbon | |
| CN104592108A (en) | One-step synthetic process of rubber antioxidant RD | |
| CN210656752U (en) | Device for washing glycine crude product by alcohol phase method | |
| CN106587067A (en) | Method for recycling silicon powder from silicon-containing waste residues | |
| CN102617741B (en) | Process for producing hydroxy propyl cellulose with high substitution degree | |
| CN205031917U (en) | A DME recovery unit for in HPMC production | |
| CN204147853U (en) | A kind of reaction dewater unit | |
| CN102633308A (en) | Method for producing iron oxide black by ferrous sulfate mother liquor | |
| CN104531364B (en) | A kind of method for being catalyzed high acid value waste oil esterification acid reduction | |
| CN102001917B (en) | Method for recovering hydroquinone serving as raw material from waste liquid produced in production process of tert butyl hydroquinone |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |