JPH0562602B2 - - Google Patents
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- Publication number
- JPH0562602B2 JPH0562602B2 JP4059885A JP4059885A JPH0562602B2 JP H0562602 B2 JPH0562602 B2 JP H0562602B2 JP 4059885 A JP4059885 A JP 4059885A JP 4059885 A JP4059885 A JP 4059885A JP H0562602 B2 JPH0562602 B2 JP H0562602B2
- Authority
- JP
- Japan
- Prior art keywords
- polymer
- paste
- concentration
- acrylamide
- aqueous solution
- 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
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- 229920000642 polymer Polymers 0.000 claims description 70
- 239000007864 aqueous solution Substances 0.000 claims description 18
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 14
- 150000003839 salts Chemical class 0.000 claims description 14
- 239000002253 acid Substances 0.000 claims description 11
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 9
- 238000000354 decomposition reaction Methods 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
- 239000011780 sodium chloride Substances 0.000 claims description 7
- 239000003638 chemical reducing agent Substances 0.000 claims description 6
- 238000006386 neutralization reaction Methods 0.000 claims description 6
- 239000003513 alkali Substances 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 235000011837 pasties Nutrition 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 description 17
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 238000003756 stirring Methods 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 229920002401 polyacrylamide Polymers 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- -1 dimethylaminoethyl Chemical group 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 235000011121 sodium hydroxide Nutrition 0.000 description 3
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 239000005708 Sodium hypochlorite Substances 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 125000003277 amino group Chemical group 0.000 description 2
- 229920006317 cationic polymer Polymers 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 2
- 235000010265 sodium sulphite Nutrition 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 238000006105 Hofmann reaction Methods 0.000 description 1
- 229910019093 NaOCl Inorganic materials 0.000 description 1
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 1
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 125000003368 amide group Chemical group 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- UKFXDFUAPNAMPJ-UHFFFAOYSA-N ethylmalonic acid Chemical compound CCC(C(O)=O)C(O)=O UKFXDFUAPNAMPJ-UHFFFAOYSA-N 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 235000011181 potassium carbonates Nutrition 0.000 description 1
- 235000011118 potassium hydroxide Nutrition 0.000 description 1
- SATVIFGJTRRDQU-UHFFFAOYSA-N potassium hypochlorite Chemical compound [K+].Cl[O-] SATVIFGJTRRDQU-UHFFFAOYSA-N 0.000 description 1
- ORQYPOUSZINNCB-UHFFFAOYSA-N potassium;hypobromite Chemical compound [K+].Br[O-] ORQYPOUSZINNCB-UHFFFAOYSA-N 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000001632 sodium acetate Substances 0.000 description 1
- 235000017281 sodium acetate Nutrition 0.000 description 1
- HRZFUMHJMZEROT-UHFFFAOYSA-L sodium disulfite Chemical compound [Na+].[Na+].[O-]S(=O)S([O-])(=O)=O HRZFUMHJMZEROT-UHFFFAOYSA-L 0.000 description 1
- 229940001584 sodium metabisulfite Drugs 0.000 description 1
- 235000010262 sodium metabisulphite Nutrition 0.000 description 1
- 239000004317 sodium nitrate Substances 0.000 description 1
- 235000010344 sodium nitrate Nutrition 0.000 description 1
- JXKPEJDQGNYQSM-UHFFFAOYSA-M sodium propionate Chemical compound [Na+].CCC([O-])=O JXKPEJDQGNYQSM-UHFFFAOYSA-M 0.000 description 1
- 239000004324 sodium propionate Substances 0.000 description 1
- 235000010334 sodium propionate Nutrition 0.000 description 1
- 229960003212 sodium propionate Drugs 0.000 description 1
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 description 1
- 235000019345 sodium thiosulphate Nutrition 0.000 description 1
- CRWJEUDFKNYSBX-UHFFFAOYSA-N sodium;hypobromite Chemical compound [Na+].Br[O-] CRWJEUDFKNYSBX-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 235000010269 sulphur dioxide Nutrition 0.000 description 1
Landscapes
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明はホフマン分解されたアクリルアミド系
ポリマーの製法に関するもので、詳しくは、良好
な流動状態を保持することができるペースト状ポ
リマーの製法に関するものである。
〔従来の技術〕
アクリルアミド系ポリマーの一部をホフマン分
解したカチオン性ポリマーは特有の性能を有する
高分子凝集剤として有用なものである。このポリ
マーは通常、アクリルアミド系ポリマーを水溶液
中で、下記反応式に従つて、苛性ソーダの存在
下、次亜塩素酸ソーダと反応させることにより製
造される。
〔発明が解決しようとする問題点〕
しかしながら、この反応を実施する場合、ポリ
マー水溶液の濃度が高いと粘度が高くなり、混合
物の撹拌が困難となるので、ポリマー濃度が例え
ば、５〜10％程度と言う希薄水溶液中にて行なわ
れる。また、このアクリルアミド系ポリマーのホ
フマン分解反応は発熱反応であるが、反応温度を
比較的低温に抑えた方が望ましいので、反応系の
除熱操作の面からもポリマー水溶液の濃度は低い
方が好ましい。しかし、このような低濃度の原料
を用いると反応後の製品濃度が低くなりそのまま
水溶液で製品とする場合には輸送のコストが大き
く、又、脱水して粉体を得、これを製品とするに
も、脱水負荷量が大きく実用上問題があつた。
特開昭58−108206にはホフマン反応液をHC1
等の酸で中和するとポリマーが析出し、この析出
ポリマー層に水を添加することによつてペースト
状の高濃度水溶液とする方法が記載されている。
しかし、この方法で得られる製品水溶液はなお濃
度が低く、その実施例では固形分量で５％、12
％、15％である。また、この方法において、ポリ
マー層への水の添加量を減少し、ポリマー濃度の
高い製品を得た場合には、ポリマーの流動性が不
良となるばかりか、時間経過によりポリマー粒子
が相互にくつつき合い一体化すると言う欠点を有
する。
〔問題点を解決するための手段〕
本発明者等は上記実情に鑑み、ポリマー濃度が
高くても流動性が良好であり、しかも、時間経過
によりポリマーが一体化することのないペースト
状ポリマーを得ることを目的として種々検討した
結果、中和後の混合物を20℃以下の温度に冷却す
ることにより流動性の極めて良好なペースト状ポ
リマーが得られること、更に、このペースト状ポ
リマー中の塩化ナトリウム量を反応によつて生成
する量よりも高濃度に調節することにより保存時
又は輸送時などにおいてポリマーが一体化しない
ことを見い出し本発明を完成した。
すなわち、本発明の要旨は、アクリルアミド系
ポリマーを水溶液中でアルカリの存在下、次亜ハ
ロゲン酸と反応させた後、還元剤を添加し、次い
で、中和して得られる混合物を冷却することによ
り濃縮されたペースト状ポリマーを沈降させ、こ
れを分液回収するペースト状ポリマーの製法にお
いて、中和後の混合物の冷却温度を20℃以下と
し、しかも、分液回収されたペースト状ポリマー
中に含有される１価の酸塩の濃度を水に対して、
15〜40重量％に調節することを特徴とするホフマ
ン分解されたアクリルアミド系ポリマーの製法に
存する。
以下、本発明を詳細に説明する。
本発明はアクリルアミド系ポリマーを水溶液中
でアルカリの存在下、次亜ハロゲン酸塩と反応さ
せて、部分的にホフマン分解されたカチオン性ポ
リマーを製造するものであるが、本発明では通
常、アミド基の20モル％以上、好ましくは30〜
100モル％がホフマン分解されたポリマーを得る。
また、原料として用いるアクリルアミド系ポリマ
ーとしては、通常、アクリルアミドの単独重合体
のほか、アクリルアミドと例えば、ジメチルアミ
ノエチル（メタ）アクリレート又はその４級塩な
どの共重合可能なモノマーとの共重合体が挙げら
れる。このポリマーの水溶液濃度は高い方が後の
生成ポリマーの回収が容易となるので好ましい
が、この濃度があまり高い場合には、水溶液の粘
度が上昇し撹拌が困難となるので、通常、１〜15
重量％、好ましくは５〜10重量％の範囲から選ば
れる。
一方、次亜ハロゲン酸塩としては通常、次亜塩
素酸ソーダ、次亜臭素酸ソーダ、次亜塩素酸カ
リ、次亜臭素酸カリなどが挙げられる。次亜ハロ
ゲン酸塩は理論的にはホフマン分解しようとする
ポリマー中のアミド基１モルに対し、１モルが必
要であるが、通常、次亜ハロゲン酸塩は反応系内
で完全に反応しないので、目標とする分解率の理
論量に対して、1.0〜2.5倍モルの次亜ハロゲン酸
塩が用いられる。
また、アルカリとしては通常、苛性ソーダ、苛
性カリ、炭酸ソーダ、炭酸カリなどが挙げられ
る。このアルカリの使用量は通常、使用する次亜
ハロゲン酸塩に対して、1.5〜５倍モル、好まし
くは1.6〜３倍モルである。
本発明におけるアクリルアミド系ポリマーのホ
フマン分解反応は発熱反応であるが、通常、−５
〜60℃、好ましくは０〜50℃の温度で実施され
る。反応温度があまり高い場合には、得られるポ
リマー中のアミノ基が減少する傾向があり好まし
くない。また、反応時間は反応条件により異なる
が通常、10〜120分間程度である。反応の終点は
系内の温度上昇がなくなた時点であるので、系内
の温度変化を測定することにより簡単に知ること
ができる。
反応終了後の混合物には未反応の次亜ハロゲン
酸塩が残存しているので、通常、直ちに、還元剤
を添加して次亜ハロゲン酸塩を消滅させることが
好ましい。
もし、還元剤を加えることなく長時間放置した
場合には、得られるポリマー中のアミノ基が減少
し、ポリマー性能が低下するので好ましくない。
この還元剤の具体例としては、例えば、亜硫酸ソ
ーダ、チオ硫酸ソーダ、酸性亜硫酸ソーダ、メタ
重亜硫酸ソーダ、亜硫酸ガス、アセトン、マロン
酸エチルなどが挙げられる。この還元剤の使用量
は通常、反応に用いた次亜ハロゲン酸塩に対し
て、0.005〜0.15倍モル、好ましくは0.05〜0.1倍
モルである。
次いで、混合物に酸を加え中和するが、酸とし
ては、通常、塩酸、硫酸などの無機酸、酢酸、蓚
酸などの有機酸が挙げられ、なかでも、塩酸が好
ましい。酸の添加量は通常、系内のPHが７以下、
好ましくは３〜６になるまで行なわれる。この中
和処理は混合物が高温のうちに実施してもよく、
また、後述する混合物の冷却時に実施しても差し
支えない。
上記の混合物は冷却することによりポリマーが
析出し沈降するが、本発明ではこの際の冷却温度
を20℃以下、好ましくは10℃以下とすることが必
要である。この温度が高い場合には、ポリマーの
析出量が少ない上、流動性の良好なポリマーが得
られないので好ましくない。また、本発明では冷
却時の初期に10分間以上の撹拌処理を施した後、
静置処理を施すと、沈降性の優れた良好なポリマ
ーが析出するので好ましい。この場合の静置時間
は装置の形式、規模などによつて異なるが、通
常、0.5〜24時間である。
このように沈降させて得たペースト状ポリマー
は常法により分液し回収されるが、このポリマー
濃度は通常、15〜30重量％と高濃度なものであ
る。このペースト状ポリマーは例えば、10℃以下
の低温で保存した場合には、比較的安定であるも
のの、常温付近の温度において保存する場合に
は、ポリマー粒子が相互にくつつき合い一体化す
ることとなる。
そこで、本発明においては、ペースト状ポリマ
ー中に含有される１価の酸塩の濃度を水に対し
て、15〜40重量％、好ましくは15〜25重量％に調
節することを必須の要件とするものである。ペー
スト状ポリマー中には反応で生成した塩化ナトリ
ウムなどの塩が含有されているが、この程度の存
在量ではペースト状ポリマーを安定に保存すると
の面からは不十分であるので、更に、所定量の塩
を加えてその含有量を前記範囲に調節することが
必要である。また、塩を40重量％以上添加しても
効果の差はなく、塩が析出するおそれもあるので
好ましくない。ここで用いられる１価の酸塩とし
ては、通常、塩化ナトリウム、硝酸ソーダなどの
無機酸塩、酢酸ソーダ、プロピオン酸ソーダなど
の有機酸塩が挙げられ、なかでも、塩化ナトリウ
ムが好ましい。
ペースト状ポリマー中に所定量の塩を存在させ
る方法としては、通常、分液後のペースト状ポリ
マーに対して、塩の粉末又は高濃度水溶液を添加
する方法が挙げられる。また、場合により、反応
混合物よりペースト状ポリマーを分液する以前
に、該混合物に塩を加えることにより水溶液中の
塩濃度を所望濃度に調節しておいてもよい。
〔発明の効果〕
本発明によれば高濃度で流動性の良好なペース
ト状のポリマーが得られ、しかも、このポリマー
は常温付近でも時間経過によりポリマー粒子同志
がくつつき合うこともないので、工業的に極めて
優れたものである。
〔実施例〕
実施例１〜２及び比較例
10の撹拌機付反応器に、還元粘度５のポリア
クリルアミドの10％水溶液3150ｇｒを投入し２℃
に冷却した後、この水溶液に撹拌下、14％の
NaOCl水溶液2106ｇｒと47％のNaOH水溶液
675grの混合液を別途０℃に冷却した後添加した。
反応は直ちに進行し30分后40℃となつた。次い
で、20％のNa2SO3水溶液63grを添加后、35％
HCl11115grを添加し反応液のPHを4.5とした。こ
の液を撹拌しながら１時間かけて５℃に冷却した
後、撹拌を止め２時間、静置することにより、ポ
リマーを粒子状態で沈降させた後、下相のポリマ
ー層を分液し取り出した。ここで回収したペース
ト状ポリマーの重量は1772grであり、ポリマー濃
度は17％であつた。なお、このペースト状ポリマ
ーは粒子が分散した状態で存在し流動性に富む良
好なポリマーであつた。
このペースト状ポリマーに塩化ナトリウムを添
加することにより、該ポリマー中の塩化ナトリウ
ム含有量が第１表に示す値となるように調節した
後、このポリマーを30℃の温度で１週間、放置
し、その際のペースト状ポリマーの流動性を観察
したとこ第１表に示す結果を得た。
【表】[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing an acrylamide polymer subjected to Hoffman decomposition, and more particularly, to a method for producing a paste-like polymer that can maintain a good fluidity state. It is. [Prior Art] A cationic polymer obtained by subjecting a portion of an acrylamide polymer to Hoffman decomposition is useful as a polymer flocculant having unique performance. This polymer is usually produced by reacting an acrylamide-based polymer with sodium hypochlorite in the presence of caustic soda in an aqueous solution according to the reaction formula below. [Problems to be Solved by the Invention] However, when carrying out this reaction, when the concentration of the polymer aqueous solution is high, the viscosity increases and it becomes difficult to stir the mixture. It is carried out in a dilute aqueous solution. Furthermore, although this Hofmann decomposition reaction of acrylamide-based polymers is an exothermic reaction, it is desirable to keep the reaction temperature to a relatively low temperature, so it is preferable that the concentration of the aqueous polymer solution be low in terms of heat removal operations from the reaction system. . However, when such low-concentration raw materials are used, the product concentration after the reaction is low, and if the product is directly made into an aqueous solution, the transportation cost is high.Also, it is difficult to dehydrate the product to obtain a powder. However, the amount of dehydration load was large, which caused a practical problem. In JP-A-58-108206, the Hofmann reaction solution was converted into HC1.
A method is described in which a polymer is precipitated by neutralization with an acid such as, and a paste-like highly concentrated aqueous solution is prepared by adding water to the precipitated polymer layer.
However, the product aqueous solution obtained by this method still has a low concentration, and in the example, the solid content is 5%, 12
%, 15%. In addition, in this method, if the amount of water added to the polymer layer is reduced and a product with a high polymer concentration is obtained, not only will the fluidity of the polymer become poor, but also the polymer particles will stick to each other over time. It has the disadvantage of becoming one with each other. [Means for solving the problem] In view of the above-mentioned circumstances, the present inventors have developed a paste-like polymer that has good fluidity even at high polymer concentrations and that does not integrate with the polymer over time. As a result of various studies with the aim of obtaining this, we found that a paste polymer with extremely good fluidity could be obtained by cooling the neutralized mixture to a temperature of 20°C or less, and that the sodium chloride in this paste polymer could be obtained by cooling the mixture after neutralization to a temperature of 20°C or less. The present invention was completed by discovering that by adjusting the amount to a higher concentration than the amount produced by the reaction, the polymers do not integrate during storage or transportation. That is, the gist of the present invention is to react an acrylamide-based polymer with hypohalous acid in the presence of an alkali in an aqueous solution, then add a reducing agent, and then cool the resulting mixture by neutralizing. In a method for producing a paste polymer in which a concentrated paste polymer is precipitated and separated and collected, the cooling temperature of the mixture after neutralization is 20°C or less, and in addition, the components contained in the separated and collected paste polymer are The concentration of monovalent acid salts in water,
The present invention relates to a method for producing an acrylamide-based polymer subjected to Hoffman decomposition, characterized in that the content of the acrylamide-based polymer is adjusted to 15 to 40% by weight. The present invention will be explained in detail below. In the present invention, a partially Hofmann-decomposed cationic polymer is produced by reacting an acrylamide-based polymer with a hypohalite in the presence of an alkali in an aqueous solution. 20 mol% or more, preferably 30~
A 100 mol% Hofmann degraded polymer is obtained.
In addition to acrylamide homopolymers, the acrylamide-based polymer used as a raw material usually includes a copolymer of acrylamide and a copolymerizable monomer such as dimethylaminoethyl (meth)acrylate or its quaternary salt. Can be mentioned. It is preferable that the concentration of the aqueous solution of this polymer be higher, since it will be easier to recover the produced polymer later. However, if this concentration is too high, the viscosity of the aqueous solution will increase and stirring will become difficult.
% by weight, preferably from 5 to 10% by weight. On the other hand, hypohalites typically include sodium hypochlorite, sodium hypobromite, potassium hypochlorite, potassium hypobromite, and the like. Theoretically, 1 mole of hypohalite is required for every 1 mole of amide group in the polymer to be subjected to Hoffmann decomposition, but normally hypohalite does not react completely in the reaction system. , 1.0 to 2.5 times the mole of hypohalite is used relative to the theoretical amount for the target decomposition rate. Further, examples of the alkali include usually caustic soda, caustic potash, soda carbonate, and potassium carbonate. The amount of the alkali used is usually 1.5 to 5 times, preferably 1.6 to 3 times, the amount of the hypohalite used. The Hofmann decomposition reaction of the acrylamide polymer in the present invention is an exothermic reaction, but usually -5
It is carried out at a temperature of -60°C, preferably 0-50°C. If the reaction temperature is too high, the number of amino groups in the resulting polymer tends to decrease, which is not preferable. Further, the reaction time varies depending on the reaction conditions, but is usually about 10 to 120 minutes. The end point of the reaction is the point at which the temperature within the system no longer increases, so it can be easily determined by measuring the temperature change within the system. Since unreacted hypohalite remains in the mixture after the reaction is completed, it is usually preferable to immediately add a reducing agent to eliminate the hypohalite. If the polymer is allowed to stand for a long time without adding a reducing agent, the amino groups in the obtained polymer will decrease, which is not preferable, since the polymer performance will deteriorate.
Specific examples of the reducing agent include sodium sulfite, sodium thiosulfate, acidic sodium sulfite, sodium metabisulfite, sulfur dioxide gas, acetone, and ethyl malonate. The amount of the reducing agent used is usually 0.005 to 0.15 times the mole, preferably 0.05 to 0.1 times the amount of the hypohalite used in the reaction. Next, an acid is added to the mixture to neutralize it, and the acid usually includes inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids such as acetic acid and oxalic acid, with hydrochloric acid being preferred. The amount of acid added is usually such that the pH in the system is 7 or less.
Preferably, this is carried out until the number reaches 3 to 6. This neutralization treatment may be carried out while the mixture is at a high temperature,
Moreover, it may be carried out at the time of cooling the mixture, which will be described later. When the above-mentioned mixture is cooled, the polymer precipitates and precipitates, but in the present invention, it is necessary to set the cooling temperature at this time to 20°C or lower, preferably 10°C or lower. If this temperature is high, the amount of polymer precipitated is small and a polymer with good fluidity cannot be obtained, which is not preferable. In addition, in the present invention, after performing a stirring process for 10 minutes or more at the initial stage of cooling,
It is preferable to perform a stationary treatment because a good polymer with excellent sedimentation properties is precipitated. The standing time in this case varies depending on the type and scale of the device, but is usually 0.5 to 24 hours. The paste-like polymer obtained by precipitation in this manner is separated and recovered by a conventional method, but the polymer concentration is usually as high as 15 to 30% by weight. For example, this paste-like polymer is relatively stable when stored at a low temperature of 10°C or less, but when stored at a temperature around room temperature, the polymer particles stick to each other and become integrated. . Therefore, in the present invention, it is an essential requirement to adjust the concentration of the monovalent acid salt contained in the paste polymer to 15 to 40% by weight, preferably 15 to 25% by weight, based on water. It is something to do. Paste polymers contain salts such as sodium chloride produced in reactions, but this level of presence is insufficient for stable storage of paste polymers, so a predetermined amount is added. It is necessary to add salt to adjust the content within the above range. Further, even if salt is added in an amount of 40% by weight or more, there is no difference in the effect and there is a risk that the salt will precipitate, which is not preferable. The monovalent acid salt used here usually includes inorganic acid salts such as sodium chloride and sodium nitrate, and organic acid salts such as sodium acetate and sodium propionate. Among them, sodium chloride is preferred. A method for making a predetermined amount of salt exist in a paste-like polymer is usually a method of adding a salt powder or a highly concentrated aqueous solution to the paste-like polymer after liquid separation. Further, in some cases, before separating the paste polymer from the reaction mixture, the salt concentration in the aqueous solution may be adjusted to a desired concentration by adding salt to the mixture. [Effects of the Invention] According to the present invention, a paste-like polymer with high concentration and good fluidity can be obtained, and since the polymer particles of this polymer do not stick together over time even at room temperature, it is suitable for industrial use. It is extremely excellent. [Example] Examples 1 to 2 and Comparative Example 3150 gr of a 10% aqueous solution of polyacrylamide with a reduced viscosity of 5 was charged into a reactor equipped with a stirrer at 2°C.
After cooling to , add 14% to this aqueous solution under stirring.
NaOCl aqueous solution 2106gr and 47% NaOH aqueous solution
675 gr of the mixture was added after being separately cooled to 0°C.
The reaction proceeded immediately and the temperature reached 40°C after 30 minutes. Then add 63gr of 20% Na 2 SO 3 aqueous solution, then 35%
11115gr of HCl was added to adjust the pH of the reaction solution to 4.5. After cooling this liquid to 5°C over 1 hour while stirring, the stirring was stopped and the polymer was allowed to stand for 2 hours to precipitate the polymer in the form of particles, and then the lower phase polymer layer was separated and taken out. . The weight of the paste-like polymer recovered here was 1772 gr, and the polymer concentration was 17%. In addition, this paste-like polymer existed in a state in which particles were dispersed and was a good polymer with good fluidity. By adding sodium chloride to this paste-like polymer, the sodium chloride content in the polymer was adjusted to the value shown in Table 1, and then the polymer was left at a temperature of 30°C for one week, The fluidity of the paste polymer was observed and the results shown in Table 1 were obtained. 【table】
Claims (1)
カリの存在下、次亜ハロゲン酸と反応させた後、
還元剤を添加し、次いで、中和して得られる混合
物を冷却することにより濃縮されたペースト状ポ
リマーを沈降させ、これを分液回収するペースト
状ポリマーの製法において、中和後の混合物の冷
却温度を20℃以下とし、しかも、分液回収された
ペースト状ポリマー中に含有される１価の酸塩の
濃度を水に対して、15〜40重量％に調節すること
を特徴とするホフマン分解されたアクリルアミド
系ポリマーの製法。 ２ ペースト状ポリマー中のポリマー濃度が15〜
30重量％である特許請求の範囲第１項記載の方
法。 ３ １価の酸塩が塩化ナトリウムである特許請求
の範囲第１項記載の方法。[Claims] 1. After reacting an acrylamide-based polymer with hypohalous acid in the presence of an alkali in an aqueous solution,
In a process for producing a pasty polymer in which a reducing agent is added and then the mixture obtained by neutralization is cooled to precipitate a concentrated paste-like polymer, and this is separated and collected, the cooling of the mixture after neutralization is performed. Hoffmann decomposition characterized by keeping the temperature below 20°C and adjusting the concentration of the monovalent acid salt contained in the separated and collected paste polymer to 15 to 40% by weight based on water. A manufacturing method for acrylamide-based polymers. 2 Polymer concentration in paste polymer is 15~
30% by weight. 3. The method according to claim 1, wherein the monovalent acid salt is sodium chloride.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4059885A JPS61200103A (en) | 1985-03-01 | 1985-03-01 | Production of acrylamide polymer decomposed by hofmann decomposition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4059885A JPS61200103A (en) | 1985-03-01 | 1985-03-01 | Production of acrylamide polymer decomposed by hofmann decomposition |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61200103A JPS61200103A (en) | 1986-09-04 |
| JPH0562602B2 true JPH0562602B2 (en) | 1993-09-08 |
Family
ID=12584945
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4059885A Granted JPS61200103A (en) | 1985-03-01 | 1985-03-01 | Production of acrylamide polymer decomposed by hofmann decomposition |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61200103A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07207751A (en) * | 1994-01-13 | 1995-08-08 | Kajima Corp | Concrete strength allocation method for columns and beams |
| JP3041754U (en) * | 1997-03-25 | 1997-10-03 | 株式会社間組 | Half precast slab |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5292821A (en) * | 1988-12-28 | 1994-03-08 | Mitsui Toatsu Chemicals, Inc. | Catonic acrylamide polymers and the applications of these polymers |
| JP2860554B2 (en) * | 1988-12-28 | 1999-02-24 | 三井化学株式会社 | Method for producing cationic acrylamide polymer and use thereof |
| US5239014A (en) * | 1988-12-28 | 1993-08-24 | Mitsui Toatsu Chemicals, Inc. | Cationic acrylamide polymers and the applications of these polymers |
| US5489626A (en) * | 1993-11-24 | 1996-02-06 | Mitsui Toatsu Chemicals, Inc. | Admixture for hydraulic cement |
-
1985
- 1985-03-01 JP JP4059885A patent/JPS61200103A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07207751A (en) * | 1994-01-13 | 1995-08-08 | Kajima Corp | Concrete strength allocation method for columns and beams |
| JP3041754U (en) * | 1997-03-25 | 1997-10-03 | 株式会社間組 | Half precast slab |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61200103A (en) | 1986-09-04 |
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