JPH0819063B2 - Method for storing N-vinylformamide - Google Patents
Method for storing N-vinylformamideInfo
- Publication number
- JPH0819063B2 JPH0819063B2 JP62096499A JP9649987A JPH0819063B2 JP H0819063 B2 JPH0819063 B2 JP H0819063B2 JP 62096499 A JP62096499 A JP 62096499A JP 9649987 A JP9649987 A JP 9649987A JP H0819063 B2 JPH0819063 B2 JP H0819063B2
- Authority
- JP
- Japan
- Prior art keywords
- vinylformamide
- water
- soluble polymer
- storage
- viscosity
- 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.)
- Expired - Fee Related
Links
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、Ｎ−ビニルホルムアミドの貯蔵方法に関す
るものである。TECHNICAL FIELD The present invention relates to a method of storing N-vinylformamide.
〔従来の技術〕 Ｎ−ビニルホルムアミドは、優れた凝集性能を有する水
溶性ポリマーを与える重合性モノマーとして有用なもの
であり、その製造法としては、例えば下記反応式で示す
ように、アセトアルデヒドとホルムアミドとを反応させ
て得られるＮ−（α−ヒドロキシエチル）ホルムアミド
をアルコールによりエーテル化してＮ−（α−アルコキ
シエチル）ホルムアミドとし、次いでこれを高温で熱分
解することによりＮ−ビニルホルムアミドを得る方法が
知られている。すなわち、下記反応式： 上述の方法においては、Ｎ−ビニルホルムアミドは、
Ｎ−（α−アルコキシエチル）ホルムアミドの熱分解に
より得られるため、副生するアルコールとの熱分解混合
物として回収される。[Prior Art] N-vinylformamide is useful as a polymerizable monomer that gives a water-soluble polymer having excellent aggregation performance, and its production method is, for example, as shown in the following reaction formula, acetaldehyde and formamide. A method for obtaining N-vinylformamide by etherifying N- (α-hydroxyethyl) formamide obtained by reacting with and to N- (α-alkoxyethyl) formamide, which is then pyrolyzed at high temperature. It has been known. That is, the following reaction formula: In the above method, N-vinylformamide is
Since it is obtained by thermal decomposition of N- (α-alkoxyethyl) formamide, it is recovered as a thermal decomposition mixture with by-produced alcohol.
そして、この熱分解混合物を蒸留してアルコールを分
解することによりＮ−ビニルホルムアミドを単離するこ
とができる。Then, N-vinylformamide can be isolated by distilling the pyrolysis mixture to decompose alcohol.
こうして得られるＮ−ビニルホルムアミドは重合して
水溶性ポリマーとするが、この水溶性ポリマーの粘度は
できるだけ高いほうが望ましい。The N-vinylformamide thus obtained is polymerized into a water-soluble polymer, and it is desirable that the viscosity of the water-soluble polymer be as high as possible.
ところが、前記の方法で蒸留回収後一定期間貯蔵した
Ｎ−ビニルホルムアミドを重合した場合に得られる水溶
性ポリマーは、蒸留回収直後に同様の方法で重合して得
られる水溶性ポリマーに比べて粘度が低い。この原因は
明らかではないが、Ｎ−ビニルホルムアミドの貯蔵中に
その一部が変質するためと推測される。例えば、蒸留直
後のＮ−ビニルホルムアミドを重合した時に還元粘度が
5.2sp/cの水溶性ポリマーが得られた場合、そのモノマ
ーを常温で２ヶ月間貯蔵した後では、同様の方法で重合
して得た水溶性ポリマーの還元粘度は3.8sp/cに低下す
る。However, the water-soluble polymer obtained by polymerizing the N-vinylformamide stored for a certain period after the distillation recovery by the above method has a viscosity higher than that of the water-soluble polymer obtained by the polymerization by the same method immediately after the distillation recovery. Low. The cause of this is not clear, but it is presumed that a part of N-vinylformamide is deteriorated during storage. For example, when N-vinylformamide immediately after distillation is polymerized, the reduced viscosity is
When a water-soluble polymer of 5.2sp / c is obtained, the reduced viscosity of the water-soluble polymer obtained by polymerizing by the same method is reduced to 3.8sp / c after the monomer is stored at room temperature for 2 months. .
このように水溶性ポリマーの粘度に影響を及ぼすＮ−
ビニルホルムアミドの変質は、貯蔵時の温度を例えば５
〜10℃と低くすることによりかなり改善されるものの、
変質を十分に抑えることはできなかった。Thus, N- which affects the viscosity of the water-soluble polymer
Deterioration of vinylformamide is such that the temperature during storage is, for example, 5
Although it can be improved considerably by lowering it to ~ 10 ℃,
The deterioration could not be suppressed sufficiently.
そこで、本発明者らは、上記問題点を解決すべく鋭意
検討を重ねた結果、本発明を完成した。Therefore, the present inventors have completed the present invention as a result of intensive studies to solve the above problems.
すなわち、本発明の骨子は、Ｎ−ビニルホルムアミド
を、５倍量（重量倍）の水で希釈した際のpHを６〜８と
して、不活性ガス雰囲気下で貯蔵することにより貯蔵中
の変質を防止し、このＮ−ビニルホルムアミドを重合し
て得られる水溶性ポリマーの粘度を高いまま保持できる
ことを初めて見い出したことにある。That is, the gist of the present invention is that the N-vinylformamide is diluted with 5 times amount (weight times) of water to have a pH of 6 to 8 and is stored in an inert gas atmosphere to prevent deterioration during storage. For the first time, it was discovered that the water-soluble polymer obtained by polymerizing this N-vinylformamide can be prevented and the viscosity can be kept high.
以下、本発明を詳細に説明する。 Hereinafter, the present invention will be described in detail.
本発明の貯蔵方法で対象となるＮ−ビニルホルムアミ
ドは、どのような製法で得られたものでも差し支えない
が、例えばアセトアルデヒドとホルムアミドとを反応さ
せて得られるＮ−（α−ヒドロキシエチル）ホルムアミ
ドをメトキシ化し、次いでこれを熱分解することにより
得られるＮ−ビニルホルムアミドが挙げられる。その場
合には、得られる熱分解混合物はＮ−ビニルホルムアミ
ドとメタノールとの混合物であるので、通常、これを蒸
留してメタノールを除去する必要がある。The target N-vinylformamide in the storage method of the present invention may be obtained by any production method, but for example, N- (α-hydroxyethyl) formamide obtained by reacting acetaldehyde with formamide can be used. Mention may be made of N-vinylformamide obtained by methoxylation and subsequent thermal decomposition thereof. In that case, the resulting pyrolysis mixture is a mixture of N-vinylformamide and methanol, which usually needs to be distilled to remove the methanol.
本発明においては、Ｎ−ビニルホルムアミドを不活性
ガス雰囲気下で貯蔵することを必須要件とするが、その
方法としては、通常、貯蔵容器の気相部を不活性ガスで
置換する方法、あるいはＮ−ビニルホルムアミドを不活
性ガスで曝気する方法が採用される。また、場合によっ
ては、貯蔵期間中、不活性ガスを継続的に流通させても
よい。不活性ガスとしては、窒素の他にアルゴン等を使
用することができる。In the present invention, it is an essential requirement to store N-vinylformamide in an inert gas atmosphere. As a method therefor, a method of replacing the gas phase part of the storage container with an inert gas, or N A method of aerating vinylformamide with an inert gas is adopted. Further, in some cases, the inert gas may be continuously circulated during the storage period. As the inert gas, argon or the like can be used in addition to nitrogen.
Ｎ−ビニルホルムアミドの貯蔵に供する容器には、空
気の流通を防ぐことが可能な密閉容器が用いられ、この
容器の表面の材質は、ステンレス、合成樹脂、ガラス等
が好ましい。As a container for storing N-vinylformamide, a closed container capable of preventing the flow of air is used, and the surface material of this container is preferably stainless steel, synthetic resin, glass or the like.
貯蔵時の温度はできるだけ低温が望ましく、通常15〜
40℃の温度で貯蔵されるが、本発明の貯蔵方法において
は、比較的高温でも良好に貯蔵することができる。Storage temperature should be as low as possible, usually 15-
Although it is stored at a temperature of 40 ° C., the storage method of the present invention allows good storage even at a relatively high temperature.
また、本発明において、Ｎ−ビニルホルムアミドを５
倍量（重量倍）の水で希釈した際のpHを６〜８として貯
蔵する。通常の方法により蒸留回収されるＮ−ビニルホ
ルムアミドのpH（５倍量（重量倍）の水で希釈した際の
pH）はその合成条件によって異なるが、通常４〜９程度
の範囲にある。ところが、このpHがあまり高いもの、あ
るいは低いものをそのままの状態で貯蔵すると、Ｎ−ビ
ニルホルムアミドの一部が変質し、純度の低下を招くの
である。これを防止するためのpHの調整は、通常、蒸留
後のＮ−ビニルホルムアミドに、例えば、水酸化ナトリ
ウム、水酸化カリウム等のアルカリ水溶液を添加するこ
とにより行われる。Further, in the present invention, N-vinylformamide is added to 5
It is stored with a pH of 6 to 8 when diluted with a double amount (weight times) of water. The pH of N-vinylformamide, which is distilled and recovered by an ordinary method (when diluted with water of 5 times (weight times))
The pH) varies depending on the synthesis conditions, but is usually in the range of about 4-9. However, if a substance having a very high pH or a substance having a low pH is stored in the state as it is, a part of the N-vinylformamide is altered and the purity is lowered. The pH adjustment to prevent this is usually carried out by adding an aqueous alkaline solution such as sodium hydroxide or potassium hydroxide to the distilled N-vinylformamide.
次に、本発明を実施例により更に具体的に説明する
が、本発明は、その要旨を超えない限り、以下の実施例
に限定されるものではない。なお、「％」は、とくに断
らない限り、「重量％」を表す。Next, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. In addition, "%" represents "wt%" unless otherwise specified.
実施例１ 実験に用いた原料のＮ−ビニルホルムアミドは純度94
％であり、このＮ−ビニルホルムアミドを５倍量の水で
希釈した溶液のpHは４である。Example 1 The raw material N-vinylformamide used in the experiment had a purity of 94.
%, And the pH of a solution of this N-vinylformamide diluted with 5 volumes of water is 4.
上記のＮ−ビニルホルムアミドに0.5N水酸化ナトリウ
ム水溶液を添加し、５倍量の水で希釈したときのpHが6.
5になるように調整した。このpH調整したＮ−ビニルホ
ルムアミド50mlを仕込み、これに窒素ガス2lを10分間で
液中に供給し、系内を完全に窒素ガスで置換した後、そ
のままの状態で密閉し、80℃の温度の恒温槽中で70分
間、貯蔵の加速モデルテストを行った。その後、このＮ
−ビニルホルムアミドの純度を測定してから重合を行い
水溶性ポリマーを製造し、得られたポリマーの還元粘度
を測定した。結果を第一表に示す。A 0.5N aqueous sodium hydroxide solution was added to the above N-vinylformamide, and the pH when diluted with 5 times the amount of water was 6.
Adjusted to be 5. 50 ml of this pH-adjusted N-vinylformamide was charged, and 2 liters of nitrogen gas was fed into the solution for 10 minutes to completely replace the inside of the system with nitrogen gas. The accelerated model test of storage was carried out for 70 minutes in a constant temperature bath. Then this N
-The purity of vinylformamide was measured and then polymerized to produce a water-soluble polymer, and the reduced viscosity of the obtained polymer was measured. The results are shown in Table 1.
なお、Ｎ−ビニルホルムアミドの重合及びそれによっ
て得たポリマーの還元粘度の測定は以下に記す方法で行
なった。The polymerization of N-vinylformamide and the measurement of the reduced viscosity of the polymer thus obtained were carried out by the method described below.
（重合方法） Ｎ−ビニルホルムアミドのモノマー濃度60％水溶液
に、重合開始剤として、2,2′−アゾビスアミジノプロ
パン塩酸塩をモノマーに対して3000ppm添加し、分散安
定剤として0.5％のエチルセルロースを溶解したシクロ
ヘキサン媒体中で、70℃の温度で懸濁重合を行なった。
得られたポリマーを共沸により脱水した後濾別し、次い
で減圧乾燥した。(Polymerization method) To an aqueous solution of N-vinylformamide having a monomer concentration of 60%, 3000 ppm of 2,2'-azobisamidinopropane hydrochloride was added as a polymerization initiator to the monomer, and 0.5% of ethyl cellulose was used as a dispersion stabilizer. Suspension polymerization was carried out in a dissolved cyclohexane medium at a temperature of 70 ° C.
The obtained polymer was azeotropically dehydrated, filtered, and then dried under reduced pressure.
（還元粘度の測定方法） 上記の方法で得たポリマーを、1N食塩水を用いて0.1
％濃度の溶液に調製し、その溶液の還元粘度をオストワ
ルド粘度計により測定した。(Method of measuring reduced viscosity) The polymer obtained by the above method was treated with 1N saline solution to 0.1%.
% Solution was prepared, and the reduced viscosity of the solution was measured by an Ostwald viscometer.
比較例１ 実施例１において、Ｎ−ビニルホルムアミドを空気中
で貯蔵したこと以外は全く同様の条件で水溶性ポリマー
を製造した。結果を第一表に示す。Comparative Example 1 A water-soluble polymer was prepared under the same conditions as in Example 1, except that N-vinylformamide was stored in air. The results are shown in Table 1.
比較例２ 実施例１において、初めのpH調整を行なわないままの
Ｎ−ビニルホルムアミドを用いた以外は全く同様な方法
で貯蔵の加速テスト及び重合を行ない、水溶性ポリマー
を製造した。結果を第一表に示す。Comparative Example 2 A water-soluble polymer was produced by carrying out an accelerated storage test and polymerization in the same manner as in Example 1 except that N-vinylformamide was used without the initial pH adjustment. The results are shown in Table 1.
比較例３ 比較例２において、Ｎ−ビニルホルムアミドを空気中
で貯蔵したこと以外は全く同様の条件で水溶性ポリマー
を製造した。得られたポリマーの還元粘度を第一表に示
す。Comparative Example 3 A water-soluble polymer was prepared under the same conditions as in Comparative Example 2, except that N-vinylformamide was stored in air. The reduced viscosity of the obtained polymer is shown in Table 1.
参考例１ 実施例１において、Ｎ−ビニルホルムアミドを貯蔵の
加速テストをすることなく、蒸留回収後直ちに同様の方
法で重合した。結果を第一表に示す。Reference Example 1 In Example 1, N-vinylformamide was polymerized by the same method immediately after recovery by distillation, without performing an accelerated storage test. The results are shown in Table 1.
参考例２ 比較例１において、Ｎ−ビニルホルムアミドを貯蔵の
加速テストをすることなく、蒸留回収後直ちに同様の方
法で重合した。得られた水溶性ポリマーの還元粘度を第
一表に示す。Reference Example 2 In Comparative Example 1, N-vinylformamide was polymerized by a similar method immediately after recovery by distillation without an accelerated storage test. The reduced viscosities of the obtained water-soluble polymers are shown in Table 1.
〔発明の効果〕 本発明の方法によれば、Ｎ−ビニルホルムアミドを貯
蔵する際の変質を防止することが可能であり、その結
果、これを重合して得られる水溶性ポリマーの粘度は、
貯蔵することなく蒸留回収後直ちに重合を行なった場合
に得られる水溶性ポリマーの粘度と同じ程度に高いの
で、Ｎ−ビニルホルムアミドの長期の貯蔵において顕著
な効果を奏する。 [Effect of the Invention] According to the method of the present invention, it is possible to prevent alteration during storage of N-vinylformamide, and as a result, the viscosity of the water-soluble polymer obtained by polymerizing the N-vinylformamide is
Since the viscosity is as high as that of the water-soluble polymer obtained when the polymerization is carried out immediately after recovery by distillation without storage, the N-vinylformamide has a remarkable effect in long-term storage.
Claims (1)
倍）の水で希釈した際のpHを６〜８として、不活性ガス
雰囲気下、密閉容器中で保存することを特徴とするＮ−
ビニルホルムアミドの貯蔵方法。1. N-vinylformamide is stored in a closed container under an inert gas atmosphere with a pH of 6 to 8 when diluted with 5 times (weight times) water. −
Storage method for vinylformamide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62096499A JPH0819063B2 (en) | 1987-04-20 | 1987-04-20 | Method for storing N-vinylformamide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62096499A JPH0819063B2 (en) | 1987-04-20 | 1987-04-20 | Method for storing N-vinylformamide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63264559A JPS63264559A (en) | 1988-11-01 |
| JPH0819063B2 true JPH0819063B2 (en) | 1996-02-28 |
Family
ID=14166790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62096499A Expired - Fee Related JPH0819063B2 (en) | 1987-04-20 | 1987-04-20 | Method for storing N-vinylformamide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0819063B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3412167B2 (en) * | 1992-09-01 | 2003-06-03 | ダイヤニトリックス株式会社 | N-vinylformamide composition |
| DE19519628B4 (en) * | 1994-05-30 | 2005-07-14 | Mitsubishi Chemical Corp. | Process for stabilizing N-vinylamides |
| JP3584601B2 (en) * | 1996-03-11 | 2004-11-04 | ダイヤニトリックス株式会社 | Method for stabilizing N-vinylcarboxylic acid amide |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4995905A (en) * | 1973-01-29 | 1974-09-11 |
-
1987
- 1987-04-20 JP JP62096499A patent/JPH0819063B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63264559A (en) | 1988-11-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |