JPS6156169B2 - - Google Patents
Info
- Publication number
- JPS6156169B2 JPS6156169B2 JP54150613A JP15061379A JPS6156169B2 JP S6156169 B2 JPS6156169 B2 JP S6156169B2 JP 54150613 A JP54150613 A JP 54150613A JP 15061379 A JP15061379 A JP 15061379A JP S6156169 B2 JPS6156169 B2 JP S6156169B2
- Authority
- JP
- Japan
- Prior art keywords
- magnesium hydroxide
- copolymer
- mol
- carboxylic acid
- aqueous
- 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
Links
- 229920001577 copolymer Polymers 0.000 claims description 29
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims description 29
- 239000000347 magnesium hydroxide Substances 0.000 claims description 29
- 229910001862 magnesium hydroxide Inorganic materials 0.000 claims description 29
- 239000006185 dispersion Substances 0.000 claims description 24
- 239000000178 monomer Substances 0.000 claims description 21
- 239000000843 powder Substances 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- -1 hydroxyalkyl acrylate Chemical compound 0.000 claims description 7
- 150000001735 carboxylic acids Chemical class 0.000 claims 2
- 239000003513 alkali Substances 0.000 description 18
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 11
- 239000007864 aqueous solution Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 238000006116 polymerization reaction Methods 0.000 description 4
- 238000010992 reflux Methods 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 229940095095 2-hydroxyethyl acrylate Drugs 0.000 description 3
- OMIGHNLMNHATMP-UHFFFAOYSA-N 2-hydroxyethyl prop-2-enoate Chemical compound OCCOC(=O)C=C OMIGHNLMNHATMP-UHFFFAOYSA-N 0.000 description 3
- 125000000217 alkyl group Chemical group 0.000 description 3
- 125000004432 carbon atom Chemical group C* 0.000 description 3
- 238000007334 copolymerization reaction Methods 0.000 description 3
- 238000006477 desulfuration reaction Methods 0.000 description 3
- 230000023556 desulfurization Effects 0.000 description 3
- 238000006386 neutralization reaction Methods 0.000 description 3
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 3
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- VZCYOOQTPOCHFL-OWOJBTEDSA-N Fumaric acid Chemical compound OC(=O)\C=C\C(O)=O VZCYOOQTPOCHFL-OWOJBTEDSA-N 0.000 description 2
- WOBHKFSMXKNTIM-UHFFFAOYSA-N Hydroxyethyl methacrylate Chemical compound CC(=C)C(=O)OCCO WOBHKFSMXKNTIM-UHFFFAOYSA-N 0.000 description 2
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 2
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 2
- 239000012736 aqueous medium Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 2
- 239000011976 maleic acid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 235000011121 sodium hydroxide Nutrition 0.000 description 2
- PQUXFUBNSYCQAL-UHFFFAOYSA-N 1-(2,3-difluorophenyl)ethanone Chemical compound CC(=O)C1=CC=CC(F)=C1F PQUXFUBNSYCQAL-UHFFFAOYSA-N 0.000 description 1
- JAHNSTQSQJOJLO-UHFFFAOYSA-N 2-(3-fluorophenyl)-1h-imidazole Chemical compound FC1=CC=CC(C=2NC=CN=2)=C1 JAHNSTQSQJOJLO-UHFFFAOYSA-N 0.000 description 1
- IEVADDDOVGMCSI-UHFFFAOYSA-N 2-hydroxybutyl 2-methylprop-2-enoate Chemical compound CCC(O)COC(=O)C(C)=C IEVADDDOVGMCSI-UHFFFAOYSA-N 0.000 description 1
- NJRHMGPRPPEGQL-UHFFFAOYSA-N 2-hydroxybutyl prop-2-enoate Chemical compound CCC(O)COC(=O)C=C NJRHMGPRPPEGQL-UHFFFAOYSA-N 0.000 description 1
- VHSHLMUCYSAUQU-UHFFFAOYSA-N 2-hydroxypropyl methacrylate Chemical compound CC(O)COC(=O)C(C)=C VHSHLMUCYSAUQU-UHFFFAOYSA-N 0.000 description 1
- GWZMWHWAWHPNHN-UHFFFAOYSA-N 2-hydroxypropyl prop-2-enoate Chemical compound CC(O)COC(=O)C=C GWZMWHWAWHPNHN-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- CNCOEDDPFOAUMB-UHFFFAOYSA-N N-Methylolacrylamide Chemical compound OCNC(=O)C=C CNCOEDDPFOAUMB-UHFFFAOYSA-N 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 229940048053 acrylate Drugs 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 125000005250 alkyl acrylate group Chemical group 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- LDHQCZJRKDOVOX-NSCUHMNNSA-N crotonic acid Chemical compound C\C=C\C(O)=O LDHQCZJRKDOVOX-NSCUHMNNSA-N 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000001530 fumaric acid Substances 0.000 description 1
- VOZRXNHHFUQHIL-UHFFFAOYSA-N glycidyl methacrylate Chemical class CC(=C)C(=O)OCC1CO1 VOZRXNHHFUQHIL-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- LVHBHZANLOWSRM-UHFFFAOYSA-N methylenebutanedioic acid Natural products OC(=O)CC(=C)C(O)=O LVHBHZANLOWSRM-UHFFFAOYSA-N 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- RPQRDASANLAFCM-UHFFFAOYSA-N oxiran-2-ylmethyl prop-2-enoate Chemical class C=CC(=O)OCC1CO1 RPQRDASANLAFCM-UHFFFAOYSA-N 0.000 description 1
- 239000003505 polymerization initiator Substances 0.000 description 1
- 238000012673 precipitation polymerization Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229940047670 sodium acrylate Drugs 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- LDHQCZJRKDOVOX-UHFFFAOYSA-N trans-crotonic acid Natural products CC=CC(O)=O LDHQCZJRKDOVOX-UHFFFAOYSA-N 0.000 description 1
Description
本発明は水酸化マグネシウム水分散液の製法に
関するものである。詳しくは、特定の共重合体の
アルカリ中和物を用いる、高濃度で安定な水酸化
マグネシウム微粉末水分散液の製造方法に関する
ものである。
水酸化マグネシウムはカセイソーダや石灰と並
ぶ安価な中和源としての用途が知られている。特
に近年、湿式排煙脱硫装置の吸収液としての需要
が増加している。この目的に使用される水酸化マ
グネシウムは、最終の使用形態が吸収液としての
水分散液であるために、脱硫反応速度からは可能
な限り微粒子であることが好ましい。また、水酸
化マグネシウムの輸送は一般に水分散液の状態で
行なわれるが、この水分散液の濃度は輸送・エネ
ルギーコストの観点からすれば可能な限り高濃度
であり、その粘度も700cp程度以下であることが
好ましい。しかし、粒子径の微細な水酸化マグネ
シウムを用いると水分散液の粘度が上昇すため
に、通常用いられる１μ以下の粒子径をもつ水酸
化マグネシウム微粉末では35％程度がスラリー輸
送可能な濃度の上限であり、従つて水酸化マグネ
シウム水分散液の高濃度化が業界の強い要望であ
つた。
本発明者らは、このような現状に鑑み鋭意研究
の結果、特定の共重合体のアルカリ中和物を用い
ることにより、高濃度の水酸化マグネシウム水分
散液を工業的に製造できることを見出して本発明
を完成させるに至つた。
従つて、本発明の目的は、高濃度且つ低粘度の
水酸化マグネシウム微粉末水分散液の製法、及び
その製法において使用する特定の共重合体アルカ
リ中和物を提供する点にあるものである。
即ち、本発明の水酸化マグネシウム水分散液の
製法は、ヒドロキシアルキルアクリレート及びヒ
ドロキシアルキルメタクリレートからなる群から
選ばれた不飽和モノマー(a)及び不飽和カルボン酸
(b)を必須の成分とし、不飽和モノマー(a)を60〜５
モル％の範囲内及び不飽和カルボン酸(b)を40〜95
モル％の範囲内となる量用いて得られた共重合体
のアルカリ中和物（以下、「共重合体アルカリ中
和物」という。）の存在下に水酸化マグネシウム
微粉末を水に分散させることを特徴とするもので
ある。
本発明で用いられる「共重合体アルカリ中和
物」は、不飽和モノマー(a)及び不飽和カルボン酸
(b)を必須の成分とし、不飽和モノマー(a)を60〜５
モル％の範囲内及び不飽和カルボン酸(b)を40〜95
モル％の範囲となる量用いて得られた共重合体の
アルカリ性物質による中和物である。
不飽和モノマー(a)としては、そのアルキル基の
炭素数が２〜４個のものが用いられ、例えば２−
ヒドロキシエチルアクリレート、２−ヒドロキシ
プロピルアクリレート、２−ヒドロキシブチルア
クリレート、２−ヒドロキシエチルメタクリレー
ト、２−ヒドロキシプロピルメタクリレート、２
−ヒドロキシブチルメタクリレート等を挙げるこ
とができる。これらの中でも、特に２−ヒドロキ
シエチルアクリレートと２−ヒドロキシエチルメ
タクリレートが好ましい。不飽和カルボン酸(b)と
しては、例えばアクリル酸、メタクリル酸、マレ
イン酸、フマル酸、イタコン酸、クロトン酸など
が使用できるが、特にアクリル酸、メタクリル酸
及びマレイン酸が好ましい。不飽和モノマー(a)と
不飽和カルボン酸(b)とはそれぞれ前者が60〜５モ
ル％の範囲内の量、後者が40〜95モル％の範囲内
の量で用いられる。不飽和モノマー(a)の量が60モ
ル％を超えるか又は不飽和カルボン酸(b)の量が40
モル％未満の場合には、本発明の分散効果が充分
でなく、好ましくない。不飽和モノマー(a)の量が
５モル％未満か又は不飽和カルボン酸(b)の量が95
モル％を超える場合には、本発明の低粘度化の効
果が充分でなく、やはり好ましくない。
本発明の「共重合体アルカリ中和物」を得るに
際して、不飽和モノマー(a)が60〜５モル％及び不
飽和カルボン酸(b)が40〜95モル％の範囲内となる
限りにおいて、これらの単量体と共重合可能な他
のモノマーを共重合させることができる。このよ
うなモノマーとしては、例えば、炭素数１〜４個
のアルキル基を有するアルキルアクリレートやア
ルキルメタクリレート、グリシジルアクリレー
ト、グリシジルメタクリレート、炭素数１〜４個
のアルキル基を有するアルコキシアルキルアクリ
レートやアルコキシアルキルメタクリレート、ア
クリルアミド、Ｎ−メチロールアクリルアミド、
酢酸ビニル等を挙げることができる。
これらの単量体から本発明の「共重合体アルカ
リ中和物」を得るための重合方法としては特別な
制限はなく、種々の方法を採用することができ
る。又、アルカリ性物質による中和は、共重合反
応の前、共重合反応中、共重合反応の後のいずれ
の段階において行つてもよい。本発明の「共重合
体アルカリ中和物」を得る方法としては例えば、
不飽和モノマー(a)、不飽和カルボン酸(b)及び必要
に応じて他の共重合可能な単量体からなる混合モ
ノマーを低級アルコール中で沈澱重合法により共
重合させ、得られた共重合体を水媒体中でアルカ
リ性物質で中和する方法や、不飽和カルボン酸(b)
のアルカリ中和物と不飽和モノマー(a)及び必要に
応じて他の共重合可能な単量体とを重合開始剤と
ともに水媒体中に滴下して加熱して共重合させる
方法などを挙げることができる。又、共重合体の
重合度は10〜500の範囲であることが好ましい
が、特に限定されるものではない。
共重合体を中和するアルカリ性物質としては、
アンモニアあるいはアルカリ金属の水酸化物や炭
酸塩等を用いることができるが、特にナトリウム
の水酸化物が好ましい。アルカリ物質の使用量
は、本発明の共重合体が水溶性となる量であれば
よく、そのためには「共重合体アルカリ中和物」
の水溶液がPH６〜９の値となる量を用いればよ
い。
本発明で使用される水酸化マグネシウム微粉末
としては、例えば、脱硫などの分野で有効に使用
されている従来公知のものを使用することができ
る。
本発明に基づけば、水酸化マグネシウム微粉末
の水分散液は、「共重合体アルカリ中和物」の存
在下に水酸化マグネシウム微粉末を水に分散させ
ることにより容易に得ることができる。分散手順
に関しては特別な制限はなく、例えば「共重合体
アルカリ中和物」が水溶液の状態で得られた場合
にはその水溶液を適当に稀釈もしくは濃縮し、必
要ならば更にアルカリ性物質を加えて水溶液PHを
中性ないしアルカリ性域とし、撹拌下に水酸化マ
グネシウム微粉末を加えて分散させることにより
容易につくることができる。又、水酸化マグネシ
ウム微粉末が、製造後フイルタープレスなどで
別されたケーキ状で得られる場合には、「共重合
体アルカリ中和物」の固形物を該ケーキ状の水酸
化マグネシウムに添加し、必要に応じて水を加え
てただちに撹拌し、水分散液をつくることももち
ろん可能である。この際「共重合体アルカリ中和
物」は、水酸化マグネシウム微粉末に対して重量
で0.05〜５％、好ましくは0.1〜３％の範囲の量
で使用できる。
本発明に従えば、特に60重量％以上という高濃
度で分散安定性に優れる水酸化マグネシウム水分
散液が得られ、そして得られた水分散液は輸送や
取り扱いが極めて容易なものである。
以下、実施例及び比較例により本発明を更に詳
しく説明する。しかし、本発明はこれらの例だけ
で制限されるものではないことは云うまでもな
い。
尚、特にことわりのない限り例中の％は重量％
を、部は重量部を意味するものとする。
参考例 １
還流冷却器、３個の滴下漏斗及び温度計を取り
付けた、内容積５の６口フラスコに初期水1235
ｇを仕込み、加熱して、還流させた。ついでこの
系に溶媒の還流下、３個の滴下漏斗から２−ヒド
ロキシエチルアクリレート215ｇ、アクリル酸ナ
トリウムの30％水溶液3400ｇ及び過硫酸アンモニ
ウムの10％水溶液150ｇを均一に４時間を要して
滴下させて重合反応せしめ、更に30分間還流下で
熟成して「共重合体アルカリ中和物」(1)の水溶液
を得た。
参考例 ２〜４
第１表に記した各モノマー組成及び水の量を用
いる他は参考例１と同様にして重合反応を行い、
各種の「共重合体アルカリ中和物」の水溶液を得
た。これらの「共重合体アルカリ中和物」を、以
下それぞれ「共重合体アルカリ中和物」(2)、「共
重合体アルカリ中和物」(3)及び「共重合体アルカ
リ中和物」(4)という。
The present invention relates to a method for producing an aqueous magnesium hydroxide dispersion. Specifically, the present invention relates to a method for producing a highly concentrated and stable aqueous dispersion of fine magnesium hydroxide powder using an alkali-neutralized product of a specific copolymer. Magnesium hydroxide is known to be used as an inexpensive source of neutralization along with caustic soda and lime. Particularly in recent years, demand has increased as an absorption liquid for wet flue gas desulfurization equipment. Since the magnesium hydroxide used for this purpose is ultimately used in the form of an aqueous dispersion as an absorption liquid, from the viewpoint of the desulfurization reaction rate, it is preferable that the magnesium hydroxide be as fine a particle as possible. Furthermore, magnesium hydroxide is generally transported in the form of an aqueous dispersion, and the concentration of this aqueous dispersion is as high as possible from the viewpoint of transportation and energy costs, and its viscosity is approximately 700 cp or less. It is preferable that there be. However, when magnesium hydroxide with a fine particle size is used, the viscosity of the aqueous dispersion increases, so the normally used fine magnesium hydroxide powder with a particle size of 1μ or less has a concentration of about 35% that can be transported as a slurry. Therefore, there has been a strong desire in the industry to increase the concentration of magnesium hydroxide aqueous dispersions. In view of the current situation, the present inventors have conducted extensive research and have discovered that a highly concentrated aqueous magnesium hydroxide dispersion can be produced industrially by using an alkali-neutralized product of a specific copolymer. The present invention has now been completed. Therefore, an object of the present invention is to provide a method for producing a high-concentration, low-viscosity aqueous dispersion of fine magnesium hydroxide powder, and a specific alkali-neutralized copolymer used in the production method. . That is, the method for producing an aqueous magnesium hydroxide dispersion of the present invention involves using an unsaturated monomer (a) selected from the group consisting of hydroxyalkyl acrylate and hydroxyalkyl methacrylate and an unsaturated carboxylic acid.
(b) is an essential component, and unsaturated monomer (a) is 60 to 5
Within the range of mole% and unsaturated carboxylic acid (b) 40-95
Magnesium hydroxide fine powder is dispersed in water in the presence of an alkali-neutralized copolymer (hereinafter referred to as "alkali-neutralized copolymer") obtained by using an amount within the range of mol %. It is characterized by this. The "copolymer alkali neutralized product" used in the present invention consists of an unsaturated monomer (a) and an unsaturated carboxylic acid.
(b) is an essential component, and unsaturated monomer (a) is 60 to 5
Within the range of mole% and unsaturated carboxylic acid (b) 40-95
It is a neutralized product of a copolymer obtained by using an alkaline substance in an amount in the range of mol %. As the unsaturated monomer (a), those whose alkyl group has 2 to 4 carbon atoms are used, for example, 2-
Hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2
-Hydroxybutyl methacrylate and the like. Among these, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are particularly preferred. Examples of the unsaturated carboxylic acid (b) that can be used include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and crotonic acid, with acrylic acid, methacrylic acid, and maleic acid being particularly preferred. The unsaturated monomer (a) and the unsaturated carboxylic acid (b) are each used in an amount of 60 to 5 mol % of the former and 40 to 95 mol % of the latter. The amount of unsaturated monomer (a) exceeds 60 mol % or the amount of unsaturated carboxylic acid (b) exceeds 40 mol %
If it is less than mol %, the dispersion effect of the present invention will not be sufficient, which is not preferable. The amount of unsaturated monomer (a) is less than 5 mol % or the amount of unsaturated carboxylic acid (b) is 95
If it exceeds mol %, the effect of lowering the viscosity of the present invention is not sufficient, which is also not preferable. When obtaining the "copolymer alkali neutralized product" of the present invention, as long as the unsaturated monomer (a) is in the range of 60 to 5 mol% and the unsaturated carboxylic acid (b) is in the range of 40 to 95 mol%, Other copolymerizable monomers can be copolymerized with these monomers. Such monomers include, for example, alkyl acrylates, alkyl methacrylates, glycidyl acrylates, glycidyl methacrylates having alkyl groups having 1 to 4 carbon atoms, alkoxyalkyl acrylates and alkoxyalkyl methacrylates having alkyl groups having 1 to 4 carbon atoms. , acrylamide, N-methylolacrylamide,
Examples include vinyl acetate. There are no particular restrictions on the polymerization method for obtaining the "copolymer alkali neutralized product" of the present invention from these monomers, and various methods can be employed. Further, neutralization with an alkaline substance may be carried out at any stage before the copolymerization reaction, during the copolymerization reaction, or after the copolymerization reaction. Examples of methods for obtaining the "copolymer alkali neutralized product" of the present invention include:
A copolymer obtained by copolymerizing a mixed monomer consisting of an unsaturated monomer (a), an unsaturated carboxylic acid (b), and other copolymerizable monomers in a lower alcohol by a precipitation polymerization method. A method of neutralizing the combination with an alkaline substance in an aqueous medium, and unsaturated carboxylic acid (b)
A method of copolymerizing by dropping an alkali neutralized product of , unsaturated monomer (a), and other copolymerizable monomers together with a polymerization initiator into an aqueous medium and heating them. I can do it. Further, the degree of polymerization of the copolymer is preferably in the range of 10 to 500, but is not particularly limited. The alkaline substances that neutralize the copolymer include:
Although ammonia or alkali metal hydroxides and carbonates can be used, sodium hydroxide is particularly preferred. The amount of alkaline substance to be used may be such that the copolymer of the present invention becomes water-soluble.
It is sufficient to use an amount such that the aqueous solution has a pH value of 6 to 9. As the magnesium hydroxide fine powder used in the present invention, for example, conventionally known powders that are effectively used in fields such as desulfurization can be used. According to the present invention, an aqueous dispersion of fine magnesium hydroxide powder can be easily obtained by dispersing fine magnesium hydroxide powder in water in the presence of a "copolymer alkali neutralized product." There are no special restrictions on the dispersion procedure; for example, if the "copolymer alkali-neutralized product" is obtained in the form of an aqueous solution, the aqueous solution is appropriately diluted or concentrated, and if necessary, an alkaline substance is further added. It can be easily prepared by adjusting the pH of the aqueous solution to a neutral to alkaline range and adding and dispersing fine magnesium hydroxide powder while stirring. In addition, if the magnesium hydroxide fine powder is obtained in the form of a cake that is separated using a filter press or the like after production, a solid substance of "copolymer alkali neutralized product" is added to the cake-like magnesium hydroxide. Of course, it is also possible to create an aqueous dispersion by adding water and stirring immediately if necessary. At this time, the "copolymer alkali neutralized product" can be used in an amount ranging from 0.05 to 5% by weight, preferably from 0.1 to 3%, based on the fine magnesium hydroxide powder. According to the present invention, an aqueous magnesium hydroxide dispersion having a particularly high concentration of 60% by weight or more and excellent dispersion stability can be obtained, and the obtained aqueous dispersion is extremely easy to transport and handle. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. However, it goes without saying that the present invention is not limited only to these examples. Unless otherwise specified, percentages in examples are percentages by weight.
, parts mean parts by weight. Reference example 1 Initial water 1235 ml was placed in a 6-necked flask with an internal volume of 5 equipped with a reflux condenser, 3 dropping funnels, and a thermometer.
g and heated to reflux. Then, while the solvent was refluxing, 215 g of 2-hydroxyethyl acrylate, 3400 g of a 30% aqueous solution of sodium acrylate, and 150 g of a 10% aqueous solution of ammonium persulfate were uniformly dropped into the system over 4 hours from three dropping funnels. A polymerization reaction was carried out and the mixture was further aged under reflux for 30 minutes to obtain an aqueous solution of "copolymer alkali neutralized product" (1). Reference Examples 2 to 4 A polymerization reaction was carried out in the same manner as in Reference Example 1, except that the monomer composition and amount of water listed in Table 1 were used.
Aqueous solutions of various "copolymer alkali neutralized products" were obtained. These "copolymer alkali neutralized products" are hereinafter referred to as "copolymer alkali neutralized products" (2), "copolymer alkali neutralized products" (3), and "copolymer alkali neutralized products", respectively. (4).
【表】
比較参考例 １
初期水量を2454ｇとし、モノマー組成を２−ヒ
ドロキシエチルアクリレート848ｇ及びメタクリ
ル酸カリウムの25％水溶液1548ｇとする以外は参
考例１と同様にして「比較共重合体アルカリ中和
物」(1)の水溶液を得た。
実施例 １
内容積１のステンレス鋼製ビーカーに参考例
１で得た「共重合体アルカリ中和物」(1)25％水溶
液を23.4ｇとり、水187ｇを加えて均一に混合
し、ラボデイスパー（特殊機化社製）で撹拌しな
がら水酸化マグネシウム微粉末（１次粒子径0.3
μ）90ｇを約20分間で添加した。添加終了後
2000rpmで15分間撹拌し、水酸化マグネシウム65
％の水分散液を得た。
製造直後のこの水分散液粘度は第２表に示した
如く132cps（25℃、Ｂ型粘度計、以下同様）で
あつた。またこの水分散液を40℃で14日間放置し
た後の粘度は180cpsであつた。
実施例 ２〜４
参考例２〜４で得た各「共重合体アルカリ中和
物」を用いて実施例１と同様にして水酸化マグネ
シウムの水分散液を製造し、粘度を測定した。結
果は第２表に示したとおりであつた。
比較例 １
比較参考例１で得た「比較共重合体アルカリ中
和物」(1)を用いて実施例１と同様にして水酸化マ
グネシウム水分散液を調製し、粘度を測定した。
結果は第２表に示したとおりであつた。
比較例 ２
水300ｇを実施例１で使用したラボデイスパー
を用いて撹拌しながら水酸化マグネシウム300ｇ
を添加して、水酸化マグネシウム50％水分散液の
製造を試みたが、ペースト状になり、粘度
11500cpsとなつた。[Table] Comparative reference example 1 "Comparative copolymer alkali neutralization An aqueous solution of compound (1) was obtained. Example 1 23.4 g of the 25% aqueous solution of "copolymer alkali neutralized product" (1) obtained in Reference Example 1 was placed in a stainless steel beaker with an internal volume of 1, and 187 g of water was added thereto and mixed uniformly. Magnesium hydroxide fine powder (primary particle size 0.3
μ) 90g was added over about 20 minutes. After addition
Stir at 2000 rpm for 15 minutes and add 65% magnesium hydroxide.
% aqueous dispersion was obtained. As shown in Table 2, the viscosity of this aqueous dispersion immediately after production was 132 cps (25°C, B-type viscometer, the same applies hereinafter). Further, the viscosity of this aqueous dispersion after being left at 40° C. for 14 days was 180 cps. Examples 2 to 4 An aqueous dispersion of magnesium hydroxide was produced in the same manner as in Example 1 using each of the "copolymer alkali neutralized products" obtained in Reference Examples 2 to 4, and the viscosity was measured. The results were as shown in Table 2. Comparative Example 1 A magnesium hydroxide aqueous dispersion was prepared in the same manner as in Example 1 using the "comparative copolymer alkali neutralized product" (1) obtained in Comparative Reference Example 1, and the viscosity was measured.
The results were as shown in Table 2. Comparative Example 2 300g of magnesium hydroxide was added to 300g of water while stirring using the Lab Disper used in Example 1.
An attempt was made to make a 50% aqueous dispersion of magnesium hydroxide by adding
It became 11500cps.
Claims (1)
キシアルキルメタクリレートからなる群から選ば
れた不飽和モノマー(a)及び不飽和カルボン酸(b)を
必須の成分とし、不飽和モノマー(a)を60〜５モル
％の範囲内及び不飽和カルボン酸(b)を40〜95モル
％の範囲内となる量用いて得られた共重合体のア
ルカリ中和物の存在下に水酸化マグネシウム微粉
末を水に分散させることを特徴とする水酸化マグ
ネシウム水分散液の製法。1 Unsaturated monomer (a) selected from the group consisting of hydroxyalkyl acrylate and hydroxyalkyl methacrylate and unsaturated carboxylic acid (b) are essential components, and the unsaturated monomer (a) is within the range of 60 to 5 mol%. and unsaturated carboxylic acid (b) in an amount within the range of 40 to 95 mol%, and dispersing fine magnesium hydroxide powder in water in the presence of an alkaline neutralized copolymer. A method for producing an aqueous dispersion of magnesium hydroxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15061379A JPS5673624A (en) | 1979-11-22 | 1979-11-22 | Manufacture of aqueous magnesium hydroxide dispersion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15061379A JPS5673624A (en) | 1979-11-22 | 1979-11-22 | Manufacture of aqueous magnesium hydroxide dispersion |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5673624A JPS5673624A (en) | 1981-06-18 |
| JPS6156169B2 true JPS6156169B2 (en) | 1986-12-01 |
Family
ID=15500699
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15061379A Granted JPS5673624A (en) | 1979-11-22 | 1979-11-22 | Manufacture of aqueous magnesium hydroxide dispersion |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5673624A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6387369A (en) * | 1986-09-22 | 1988-04-18 | ティーアールダブリュー・インコーポレーテッド | Steering gear |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5514357A (en) * | 1993-04-15 | 1996-05-07 | Martin Marietta Magnesia Specialties Inc. | Stabilized magnesium hydroxide slurry |
| US5487879A (en) * | 1994-07-15 | 1996-01-30 | Martin Marietta Magnesia Specialities Inc. | Stabilized, pressure-hydrated magnesium hydroxide slurry from burnt magnesite and process for its production |
| US5824279A (en) * | 1995-01-19 | 1998-10-20 | Martin Marietta Magnesia Specialties, Inc. | Process for producing stabilized magnesium hydroxide slurries |
-
1979
- 1979-11-22 JP JP15061379A patent/JPS5673624A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6387369A (en) * | 1986-09-22 | 1988-04-18 | ティーアールダブリュー・インコーポレーテッド | Steering gear |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5673624A (en) | 1981-06-18 |
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