CN102295719A - Novel process for synthesizing formaldehyde stabilizer - Google Patents
Novel process for synthesizing formaldehyde stabilizer Download PDFInfo
- Publication number
- CN102295719A CN102295719A CN2011101161717A CN201110116171A CN102295719A CN 102295719 A CN102295719 A CN 102295719A CN 2011101161717 A CN2011101161717 A CN 2011101161717A CN 201110116171 A CN201110116171 A CN 201110116171A CN 102295719 A CN102295719 A CN 102295719A
- Authority
- CN
- China
- Prior art keywords
- formaldehyde
- stablizer
- molecular weight
- reaction
- product
- 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.)
- Pending
Links
Abstract
The invention discloses a novel process for synthesizing a formaldehyde stabilizer. The process comprises the following steps: preparing polyvinyl acetate (PVAC) and a solvent methanol into a colorless and transparent solution, wherein a used container is an enamel reaction kettle; adding paracetaldehyde under the condition of stirring; with concentrated sulfuric acid as a catalyst, carrying out heating reflux reaction at normal pressure to prepare a polycondensate of polyvinyl acetal; and carrying out neutralization, methanol solvent removal, water washing, resin dispersion formation, dewatering, vacuum drying and the like on the polycondensate to obtain the high-quality formaldehyde stabilizer (polyvinyl acetal). The process has safety in raw material storage and transport and is convenient for use; production process is safe, product quality is stable and reliable, and operation is convenient; and the process is simple and reliable, energy-saving and environmentally-friendly, and is suitable for industrialization.
Description
Technical field
The present invention relates to a kind of preparation method of formaldehyde stablizer.
Background technology
Polymerization easily takes place down in formalin low temperature, separates out formaldehyde oligomer, causes formaldehyde content to reduce, and stores the transportation difficulty.Therefore, the problem that keeps the formaldehyde stable scientific research personnel of becoming at low temperatures to explore always and study.
(claim formol polymerization retarder again, Hereinafter the same) be methyl alcohol to the formaldehyde stablizer of original adoption, discovers the methyl alcohol of adding 12% in formaldehyde solution, can make formaldehyde keep the stable of long period at a lower temperature.But, reduced the purity of formaldehyde, thereby limited its application because this method has been introduced a large amount of methyl alcohol.
The nineties in 20th century, units such as Jilin chemical research institute, Hubei University develop the stablizer of polyvinyl formal as formaldehyde in succession, after adopting the polyvinyl formal instead of methanol, solved the problem that formaldehyde used long easy polymerization, influence in winter or storage period preferably.The production of this polyvinyl formal stablizer is to be main raw material with vinyl acetate between to for plastic, tetracol phenixin, formaldehyde, at first uses vinyl acetate between to for plastic and tetracol phenixin in the presence of benzoyl peroxide (BPO), generates vinyl acetate between to for plastic-tetracol phenixin telomer.Acidic hydrolysis then adds formaldehyde and carries out acetalation, and product is with the liquid caustic soda neutrality that neutralizes, and filters, dry solid, powdery product.There are three important disadvantages in formaldehyde stablizer with this explained hereafter: the one, and solubility property is poor.This formaldehyde stablizer need add the methyl alcohol of at least 50 times of weight, and reflux could be dissolved more than 30 minutes, can only make methanol solution in advance, joins then in the formaldehyde solution, otherwise is insoluble in the formaldehyde.The 2nd, contain the chlorine root in the product.Chlorion can be incorporated in the formaldehyde solution and go, and has limited the use of formaldehyde.The 3rd, product color is dark.After joining formaldehyde solution, when especially preparing formaldehyde reagent, can have influence on the color and luster of product.This product has withdrawed from formaldehyde market substantially at present.
Chinese patent 90105480 discloses a kind of synthetic method of novel methylene stablizer.With vinyl acetate between to for plastic, methyl alcohol is raw material, and Diisopropyl azodicarboxylate (AIBN) is an initiator, and in the enamel reaction still of 500L band condenser, it is 17000～45000 polyvinyl acetate (PVA) (PVAC) resin liquid that polymerization makes viscosity-average molecular weight.Behind nitrogen (N2) expeling partial solvent, and then be hydrolyzed the acetal reaction.Reaction product is separated out particulate resins through the moulding of high-speed stirring dispersion machine, through washing, drying, promptly makes and contains acetoxyl group 10-15% (wt%), the polyvinylacetal stablizer of acetal base 50-70 (wt%) again.The stablizer that this method is produced has overcome the deficiency of aforementioned polyvinyl formal, and being applied to formaldehyde, stablize the aspect still relatively successful.But this method exists following defective: the dissolution time of product long (about about 20 hours), also need heat sometimes; Solubleness is low, also has insolubles sometimes; After particularly adding the industrial formol aqueous solution about 37%, formaldehyde can foam in transportation, and the capacity utilization of transportation tank car is had only about 70%, can not make full use of container containing; Under the low environment of temperature, add a certain amount of this stablizer, formaldehyde solution still can polymerization, can not satisfy that severe cold area stores and the needs of transportation.
Chinese patent 94109260 discloses a kind of method for preparing the formaldehyde stablizer, utilizing this method is improvement to above-mentioned patent 90105480, prepared formaldehyde stablizer, the product viscosity-average molecular weight is 10000～17000, the product solvability is good, and can not foam after adding formaldehyde solution to, can under the temperature condition of severe cold, use.
Above-mentioned two parts of patent its preparation methods are basic identical, are raw material with vinyl acetate between to for plastic, methyl alcohol, acetaldehyde all.Because the vinyl acetate between to for plastic boiling point is lower, high volatility, with vinyl acetate between to for plastic prepare polyvinyl acetate (PVA) (PVAC) for up to tens hours, during the effusion of vinyl acetate between to for plastic is arranged unavoidably, cause the yield of product to reduce, and influence production environment; 20.8 ℃ of acetaldehyde boiling points exist with gaseous form under the room temperature (25 ℃), need with special gas steel cylinder splendid attire.Reactor temperature must keep lesser temps when reinforced, and condenser also must powerful cooling could guarantee the normal operation of technological operation.Obviously, there is obvious defects in the above-mentioned technology: 1. raw materials used storage transportation inconvenience, especially acetaldehyde needs pressurized vessel, has very big potential safety hazard in the production; Production cycle long, the time of only synthetic polyvinyl acetate (PVA) (PVAC) just reached more than 15 hours; Product yield is low, and energy consumption is many, the production cost height.
It is the method for feedstock production formaldehyde stablizer-polyvinylacetal polycondensate with polyvinyl acetate (PVA) (PVAC), methyl alcohol, acetaldehyde that U.S. Pat P4085079 discloses a kind of.Specifically, this polycondensate is that the polyvinyl acetate (PVA) by weight-average molecular weight 2000-60000 is dissolved in a certain amount of methyl alcohol, and used container is a stainless steel cauldron.The acetaldehyde that adds appropriate amount then, the mixing back is reacted certain hour and is obtained under the pressure of 2kg/cm2.This polycondensate is made of 30-50% (wt%) acetoxyl group, 40-67% (wt%) vinyl acetal base and 3-10% (wt%) ethene alcohol radical.Resulting formaldehyde stablizer is dissolved at last and makes a kind of solution in the methyl alcohol, sells as liquid product.Utilize the formaldehyde stablizer of this method preparation, be used for formaldehyde solution and obtained stabilization preferably.But there is following defective in this method: 1. synthesis material has used acetaldehyde, stores transportation and uses inconvenience, and the production process potential safety hazard is bigger; 2. reaction zone press operation, the hazard level height; 3. product is a liquid, and remote transportation is very inconvenient.
In a word, need the urgent technical problem that solves of those skilled in the art to be exactly: how to use storing and transporting security easily raw material, with atmospheric synthesizing method, make the formaldehyde stablizer product of high performance-price ratio.
Summary of the invention
At the above-mentioned problems in the prior art, the objective of the invention is to design provides a kind of raw materials used storage transportation safe and convenient to use, synthesis technique safety, product simple to operate, that production cost is low, PARA FORMALDEHYDE PRILLS(91,95) solution has the efficient stable effect under the low temperature
In order to address the above problem, the invention discloses a kind of preparation method of formaldehyde stablizer, it is characterized in that, comprising:
1. substitute acetaldehyde with paraldehyde and done synthesis material, realized the safety operation of production process.The boiling point of acetaldehyde is low, has only 20.8 ℃.Exist with gaseous phase under the room temperature (25 ℃), so need to use the special cylinder splendid attire.Special cylinder belongs to pressurized vessel, all has potential safety hazard in storage and transportation process; And, when using acetaldehyde as reaction raw materials, in order to guarantee that acetaldehyde joins in the reactor with liquid state, just must use a large amount of refrigeration agents in the production process, to the reactor processing of lowering the temperature, before guaranteeing that the acetaldehyde raw material reaction fully, reactor temperature remains on below the boiling point of acetaldehyde, remains on usually about 10 ℃; Moreover, to overflow from reactor in order to prevent acetaldehyde, condenser also must use a large amount of condensing agents to lower the temperature, and this has also correspondingly increased energy consumption, has increased production cost.And the boiling point height of paraldehyde is 124.0 ℃. be liquid under the room temperature, with common polythene bucket splendid attire.The domestic market ample supply and prompt delivery store transportation and need not pressurized vessel.And, make reaction raw materials with paraldehyde, when in reactor, feeding in raw material, also need not to lower the temperature with refrigeration agent.Whole process of production has realized safety operation, and has saved a large amount of energy, has reduced production cost.The inventor is as starting point, through repeated tests, substitute with paraldehyde that acetaldehyde synthesizing formaldehyde stablizer---polyvinylacetal has obtained great success, institute's synthetic formaldehyde stablizer product meets the service requirements of formaldehyde industry fully, and quality also slightly is better than known any product now.The present invention has well cracked this and has perplexed formaldehyde stablizer industry for many years, and the technical barrier of the safety in production that never solves.
2. substitute vinyl acetate with polyvinyl acetate (PVA) (PVAC) and done synthesis material, save the reactions steps for preparing polyvinyl acetate (PVA) (PVAC) with vinyl acetic monomer, shortened the reaction times, improved production efficiency, reduced production cost, production process is oversimplified more.Because polyvinyl acetate (PVA) (PVAC) can utilize Raolical polymerizable to make easily, do not need too much initiator and chain transfer agents.At present can buy required kind easily on the domestic market, and the resin liquid that obtains has satisfactory, low relatively viscosity, do not need the solvent methanol of excessive number just can be easily with its dissolving.Thus, the inventor proves that through test of many times research substituting vinyl acetate between to for plastic synthesizing formaldehyde stablizer with polyvinyl acetate (PVA) (PVAC) is feasible fully.It is over half so just to have shortened the reaction times, has improved production efficiency, has reduced energy consumption, has reduced production cost.Owing to saved the polymerization process for preparing polyvinyl acetate (PVA) (PVAC) by vinyl acetate between to for plastic,, only just synthesized the polyvinylacetal polycondensate, so production process advantages of simple more with single step reaction.
3. reduced the bath water amount in producing, production meets environmental protection requirement more.Because the polyvinyl alcohol polycondensate that the present invention makes, wash again after in reactor, neutralizing, steam methyl alcohol earlier, so the used washing water yield is than the obvious minimizing of prior art, and, the washing water that produce in the technology only contain the inorganic salt of trace, environment there are not influence, compliance with environmental protection requirements substantially.
Synthetic route of the present invention is:
The polyvinyl acetate (PVA) that molecular weight is suitable (PVAC) is dissolved in the solvent methanol, is made into water white methanol solution, and used container is a glassed steel reaction vessels.Add paraldehyde under the stirring at normal temperature, after stirring, drip the catalyzer vitriol oil.After adding sulfuric acid, open cold condenser cooling water, interior liquid is heated to reflux temperature, keeps back flow reaction 3-6 hour.With the viscosity-average molecular weight of Ubbelohde viscometer detecting reactant, in the time of in viscosity-average molecular weight reaches 8000～15000 scopes, cooling finishes reaction.After interior liquid temp was reduced to room temperature, highly basic in the adding was 7.0～8.0 with the interior liquid pH value that neutralizes.Elder generation's normal pressure steams most methyl alcohol, the residual methyl alcohol of liquid in decompression is steamed to the greatest extent down again.Add hot water and divide three washings, the interior liquid after the washing is separated out particulate resins through the moulding of high-speed stirring dispersion machine, again through washing, drying, promptly makes efficiently, formaldehyde stablizer cheaply.In the polycondensate rosin products, the content of vinyl acetal is 20%～80% (wt%); The content of vinyl acetoxyl group is 15%～65% (wt%); Other is the ethene alcohol radical.
Wherein, the molecular weight of used polyvinyl acetate (PVA) (PVAC) is 1000～20000, preferred 1000～15000.
Used paraldehyde is industrial goods, product purity 〉=97.0%
The catalyst system therefor vitriol oil is industrial goods, concentration 93-98%
The used middle highly basic that neutralizes is meant yellow soda ash, sodium bicarbonate, Potassium ethanoate, sodium-acetate etc., preferred sodium-acetate.
Compared with prior art, major advantage of the present invention is embodied in:
1. the raw materials used storage transportation safety of the present invention, easy to use, production process safety, easy to operate;
2. synthesis technique advantages of simple, production efficiency significantly improves, the production energy-saving and environmental protection;
3. stable and reliable product quality is better than domestic like product;
4. production cost has reduced 30-35%.
Embodiment
For above-mentioned purpose of the present invention, feature and advantage are become apparent more, the invention will be further described below by specific embodiment, but protection scope of the present invention is not limited to this:
Embodiment 1.
In one 1000 liters enamel reaction still, add 860 kilograms of polyvinyl acetate (PVA) (PVAC, molecular-weight average 20000) and 600 liters of methyl alcohol, stirring and dissolving.Normal temperature adds 175 liters of paraldehydes down, fully mixes.Under the solution stirring, in about 30 minutes, add by 45 liters of sulfuric acid and 80 liters of mixing solutionss that methyl alcohol was made into.Reaction solution is heated to reflux temperature, and kept back flow reaction 3 hours, after this every 20 minutes, with the viscosity-average molecular weight of Ubbelohde viscometer detecting reactant, in the time of in viscosity-average molecular weight reaches 8000～15000 scopes, cooling finishes reaction.With the reaction solution cool to room temperature, add yellow soda ash sulfuric acid is neutralized, interior liquid pH value reaches 7.0-8.0 and is terminal point.Solvent methanol in the still is removed the overwhelming majority through the normal pressure distillation earlier from solution, remove residual surplus portion through underpressure distillation again.And the residual mucus of polycondensate is stirring and is using isopyknic hot water injection three times, after each flushing top siphon is fallen.Polycondensate mucus after will washing then is moved in the header tank, polycondensate mucus flow into the dispersion bucket that fills water through a container with porous sieve plate from header tank again, under the shear action of high-speed stirring dispersion machine, product is separated out with the fine particulate resin, filter, washing, to the pH value of wash water be neutrality.Discard moisture then, vacuum-drying below 35 ℃, packing.Obtain product formaldehyde stablizer.This polyvinylacetal polycondensate contains the vinyl acetoxyl group of 40% (wt%), the vinyl acetal of the vinyl alcohol of 5.6% (wt%) and 44.4% (wt%).
Embodiment 2
In one 1000 liters enamel reaction still, add 860 kilograms of polyvinyl acetate (PVA) (PVAC, molecular-weight average 15000) and 650 liters of methyl alcohol, stirring and dissolving.Normal temperature adds 190 liters of paraldehydes down, fully mixes.Under the solution stirring, in about 30 minutes, add by 45 liters of sulfuric acid and 70 liters of mixing solutionss that methyl alcohol was made into.Reaction solution is heated to reflux temperature, and kept back flow reaction 4 hours.Every 20 minutes, with the viscosity-average molecular weight of Ubbelohde viscometer detecting reactant, in the time of in viscosity-average molecular weight reaches 8000～15000 scopes, cooling finished reaction later on.With the reaction solution cool to room temperature, add sodium bicarbonate sulfuric acid is neutralized, interior liquid pH value reaches 7.0-8.0 and is terminal point.Solvent methanol in the still is removed the overwhelming majority through the normal pressure distillation earlier from solution, remove residual surplus portion through underpressure distillation again.And the residual mucus of polycondensate is stirring and is using isopyknic hot water injection three times, after each flushing top siphon is fallen.Polycondensate mucus after will washing then moves in the header tank, polycondensate mucus flow into the dispersion bucket that fills water through a container with porous sieve plate from header tank again, under the shear action of high-speed stirring dispersion machine, product is separated out with the fine particulate resin, filter, washing, to the pH value of wash water be neutrality.Discard moisture then, vacuum-drying below 35 ℃, packing.Obtain product formaldehyde stablizer.This polyvinylacetal polycondensate contains the vinyl acetoxyl group of 45.7% (wt%), the vinyl acetal of the vinyl alcohol of 4.7% (wt%) and 49.6% (wt%).
Embodiment 3.
In one 1000 liters enamel reaction still, add 860 kilograms of polyvinyl acetate (PVA) (PVAC, molecular-weight average 12000) and 700 liters of methyl alcohol, stirring and dissolving.Normal temperature adds 200 liters of paraldehydes down, fully mixes.Under the solution stirring, in about 30 minutes, add by 45 liters of sulfuric acid and 60 liters of mixing solutionss that methyl alcohol was made into.Reaction solution is heated to reflux temperature, and kept back flow reaction 5 hours.After this every 20 minutes, with the viscosity-average molecular weight of Ubbelohde viscometer detecting reactant, in the time of in viscosity-average molecular weight reaches 8000～15000 scopes, cooling finished reaction.With the reaction solution cool to room temperature, add sodium-acetate sulfuric acid is neutralized, interior liquid pH value reaches 7.0-8.0 and is terminal point.Solvent methanol in the still is removed the overwhelming majority through the normal pressure distillation earlier from solution, remove residual surplus portion through underpressure distillation again.And the residual mucus of polycondensate is stirring and is using isopyknic hot water injection three times, after each flushing top siphon is fallen.Polycondensate mucus after will washing then moves in the header tank, polycondensate mucus flow into the dispersion bucket that fills water through a container with porous sieve plate from header tank again, under the shear action of high-speed stirring dispersion machine, product is separated out with the fine particulate resin, filter, washing, to the pH value of wash water be neutrality.Discard moisture then, vacuum-drying below 35 ℃, packing.Obtain product formaldehyde stablizer.This polyvinylacetal polycondensate contains the vinyl acetoxyl group of 41.5% (wt%), the vinyl acetal of the vinyl alcohol of 3.5% (wt%) and 55% (wt%).
Embodiment 4.
In one 1000 liters enamel reaction still, add 860 kilograms of polyvinyl acetate (PVA) (PVAC, molecular-weight average 10000) and 600 liters of methyl alcohol, stirring and dissolving.Normal temperature adds 180 liters of paraldehydes down, fully mixes.Under the solution stirring, in about 30 minutes, add by 50 liters of sulfuric acid and 50 liters of mixing solutionss that methyl alcohol was made into.Reaction solution is heated to reflux temperature, and kept back flow reaction 6 hours.Every 20 minutes, with the viscosity-average molecular weight of Ubbelohde viscometer detecting reactant, in the time of in viscosity-average molecular weight reaches 8000～15000 scopes, cooling finished reaction later on.With the reaction solution cool to room temperature, add Potassium ethanoate sulfuric acid is neutralized, interior liquid pH value reaches 7.0-8.0 and is terminal point.Solvent methanol in the still is removed the overwhelming majority through the normal pressure distillation earlier from solution, remove residual surplus portion through underpressure distillation again.And the residual mucus of polycondensate is stirring and is using isopyknic hot water injection three times, after each flushing top siphon is fallen.Polycondensate mucus after will washing then moves in the header tank, polycondensate mucus flow into the dispersion bucket that fills water through a container with porous sieve plate from header tank again, under the shear action of high-speed stirring dispersion machine, product is separated out with the fine particulate resin, filter, washing, to the pH value of wash water be neutrality.Discard moisture then, vacuum-drying below 35 ℃, packing.Obtain product formaldehyde stablizer.This polyvinylacetal polycondensate contains the vinyl acetoxyl group of 44.3% (wt%), the vinyl acetal of the vinyl alcohol of 4.5% (wt%) and 51.2% (wt%).
Claims (9)
1. the novel method of a synthesizing formaldehyde stablizer is characterized in that
The polyvinyl acetate (PVA) that molecular weight is suitable (PVAC) is dissolved in the solvent methanol, is made into water white methanol solution, and used container is a glassed steel reaction vessels.Add paraldehyde under the stirring at normal temperature, after stirring, drip the catalyzer vitriol oil.After adding sulfuric acid, open cold condenser cooling water, interior liquid is heated to reflux temperature, keeps back flow reaction 3-6 hour.With the viscosity-average molecular weight of Ubbelohde viscometer detecting reactant, in the time of in viscosity-average molecular weight reaches 8000～15000 scopes, cooling finishes reaction.After interior liquid temp was reduced to room temperature, highly basic in the adding was 7.0～8.0 with the interior liquid pH value that neutralizes.Elder generation's normal pressure steams most methyl alcohol, the residual methyl alcohol of liquid in decompression is steamed to the greatest extent down again.Add hot water and divide three washings, reaction solution after the washing moves in the header tank, flow into the dispersion bucket that fills water through a container from header tank again with porous sieve plate, effect compacted under in high-speed stirring dispersion machine shearing force is separated out particulate resins, through washing, drying, promptly make high-effect, formaldehyde stablizer (polyvinylacetal) cheaply again.
2. according to claim 1, the molecular weight of used polyvinyl acetate (PVA) (PVAC) is 1000～20000, preferred 1000～15000.
3. according to claim 1, used paraldehyde is industrial goods, product purity 〉=97.0.％
4. according to claim 1, the used middle highly basic that neutralizes is meant yellow soda ash, sodium bicarbonate, Potassium ethanoate, sodium-acetate etc., preferred sodium-acetate.
The catalyst system therefor vitriol oil is industrial goods, concentration 93-98%.
5. the novel method of a kind of synthesizing formaldehyde stablizer as claimed in claim 1 is characterized in that reacting under normal pressure and carries out.
6. according to claim 1, determining of polycondensation terminal point is to adopt following method to realize, promptly uses the viscosity-average molecular weight of Ubbelohde viscometer detecting reactant, and in the time of in viscosity-average molecular weight reaches 8000～15000 scopes, cooling finishes reaction.
7. the reaction solution that obtains cools to room temperature (20～25 ℃), adds the alkaline matter of medium tenacity, pH value to 7.0～8.0 of liquid in the neutralization.First then normal pressure steams most of methyl alcohol, and residual small amount of methanol is to the greatest extent steamed in decompression again.Add and the isopyknic hot water of debris, divide three washings, each washings siphon is discharged.
8. according to claim 1, polycondensation liquid is when disperseing moulding with the high-speed stirring dispersion machine, and used dispersion liquid is a water.
9. according to claim 1, with gained particulate resins product suction filtration, behind the removal moisture, vacuum-drying below 35 ℃ obtains suc as formula the formaldehyde stablizer product shown in (I):
X in the following formula, N, P are natural number.In the product molecule, the content of vinyl acetal is 20%～80%; The content of vinyl acetoxyl group is 15%～65%; Other is the ethene alcohol radical.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101161717A CN102295719A (en) | 2011-05-06 | 2011-05-06 | Novel process for synthesizing formaldehyde stabilizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101161717A CN102295719A (en) | 2011-05-06 | 2011-05-06 | Novel process for synthesizing formaldehyde stabilizer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN102295719A true CN102295719A (en) | 2011-12-28 |
Family
ID=45356415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011101161717A Pending CN102295719A (en) | 2011-05-06 | 2011-05-06 | Novel process for synthesizing formaldehyde stabilizer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102295719A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102964499A (en) * | 2012-11-01 | 2013-03-13 | 安徽弘源化工科技有限公司 | Production method of efficient water-soluble formaldehyde polymerization inhibitor PVFA special resin |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4085079A (en) * | 1977-02-02 | 1978-04-18 | Monsanto Company | Formaldehyde solutions stabilized with interpolymers of vinyl acetate, vinyl acetal and vinyl alcohol |
| CN1124742A (en) * | 1994-08-16 | 1996-06-19 | 李瑞林 | High performance formol polymerization retarder and preparing process thereof |
-
2011
- 2011-05-06 CN CN2011101161717A patent/CN102295719A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4085079A (en) * | 1977-02-02 | 1978-04-18 | Monsanto Company | Formaldehyde solutions stabilized with interpolymers of vinyl acetate, vinyl acetal and vinyl alcohol |
| CN1124742A (en) * | 1994-08-16 | 1996-06-19 | 李瑞林 | High performance formol polymerization retarder and preparing process thereof |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102964499A (en) * | 2012-11-01 | 2013-03-13 | 安徽弘源化工科技有限公司 | Production method of efficient water-soluble formaldehyde polymerization inhibitor PVFA special resin |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TW467976B (en) | Polyvinyl alcohol polymer production method and polyvinyl alcohol polymer | |
| CN105236798A (en) | Preparation method of naphthalene-series water reducing agent | |
| CN103467245B (en) | Method for complexing and removing water contained in ethanol and water mixed solution by utilizing eutectic solvent | |
| CN104437651A (en) | Method for carrying out catalytic alcoholysis on polyethylene terephthalate (PET) rapidly and efficiently by use of urea-based eutectic ionic liquid | |
| CN103350990A (en) | Process for preparing phosphorous acid by hydrolyzing phosphorus trichloride | |
| CN100478368C (en) | Method for preparing polyvinyl alcohol with low ash | |
| CN112094406A (en) | Nylon 6 production process and system and product thereof | |
| CN102504253B (en) | Environmental-protection preparation method for calcium polyaspartate as agricultural calcium supplement | |
| CN102295719A (en) | Novel process for synthesizing formaldehyde stabilizer | |
| CN101811957A (en) | Preparation method of 2,2-dimethylbenzanthracene | |
| CN102659088A (en) | Water-phase synthesis method of sodium azide | |
| CN109293812B (en) | Preparation method of hydrolyzed polymaleic anhydride | |
| CN101157945B (en) | Technique for preparing glycerin ester rich in polyunsaturated fatty acid | |
| CN112592450B (en) | Method for preparing imino methylated melamine resin by three-stage flash evaporation desolventization | |
| CN107473927B (en) | Preparation process of biphenyl dichlorobenzyl | |
| CN101560295A (en) | Preparation method of polyoxy alkylidene diol fatty acid ester | |
| CN105272839A (en) | Synthesis method of diphenyl ketone | |
| CN112724394B (en) | Preparation method of cellulose polyether polyol | |
| CN110272546B (en) | Method for synthesizing polyether sulfone resin | |
| CN212166565U (en) | Dehydration evaporation plant of nylon salt liquid | |
| CN110922500B (en) | Preparation method of polydextrose with low energy consumption | |
| CN102603704A (en) | Method for lowering acid value of 1,3-propylsultone | |
| CN111320517A (en) | Preparation process of weak base oil displacement agent for oil field | |
| CN220238539U (en) | Butyl acrylate production system | |
| CN108558639A (en) | A kind of preparation method of calcium formate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20111228 |