JPS6156168B2 - - Google Patents
Info
- Publication number
- JPS6156168B2 JPS6156168B2 JP54150612A JP15061279A JPS6156168B2 JP S6156168 B2 JPS6156168 B2 JP S6156168B2 JP 54150612 A JP54150612 A JP 54150612A JP 15061279 A JP15061279 A JP 15061279A JP S6156168 B2 JPS6156168 B2 JP S6156168B2
- Authority
- JP
- Japan
- Prior art keywords
- magnesium hydroxide
- copolymer
- alkali
- water
- mol
- 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 35
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims description 34
- 239000000347 magnesium hydroxide Substances 0.000 claims description 34
- 229910001862 magnesium hydroxide Inorganic materials 0.000 claims description 34
- 239000006185 dispersion Substances 0.000 claims description 26
- 239000000178 monomer Substances 0.000 claims description 22
- 239000003513 alkali Substances 0.000 claims description 18
- 239000000843 powder Substances 0.000 claims description 13
- 229910019142 PO4 Inorganic materials 0.000 claims description 11
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 11
- 239000010452 phosphate Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- -1 hydroxyalkyl acrylate Chemical compound 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 150000001735 carboxylic acids Chemical class 0.000 claims 2
- 239000007864 aqueous solution Substances 0.000 description 14
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 11
- 238000000034 method Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 238000003756 stirring Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 229940095095 2-hydroxyethyl acrylate Drugs 0.000 description 4
- OMIGHNLMNHATMP-UHFFFAOYSA-N 2-hydroxyethyl prop-2-enoate Chemical compound OCCOC(=O)C=C OMIGHNLMNHATMP-UHFFFAOYSA-N 0.000 description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 238000006116 polymerization reaction Methods 0.000 description 4
- 238000010992 reflux Methods 0.000 description 4
- 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
- 230000000694 effects Effects 0.000 description 3
- RYCLIXPGLDDLTM-UHFFFAOYSA-J tetrapotassium;phosphonato phosphate Chemical compound [K+].[K+].[K+].[K+].[O-]P([O-])(=O)OP([O-])([O-])=O RYCLIXPGLDDLTM-UHFFFAOYSA-J 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
- 229940048053 acrylate Drugs 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 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
- 238000010438 heat treatment Methods 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
- 238000006386 neutralization reaction Methods 0.000 description 2
- 235000019982 sodium hexametaphosphate Nutrition 0.000 description 2
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical compound [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 description 2
- 235000011121 sodium hydroxide Nutrition 0.000 description 2
- 239000001577 tetrasodium phosphonato phosphate Substances 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
- 239000002253 acid Substances 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 150000001447 alkali salts 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
- LDHQCZJRKDOVOX-NSCUHMNNSA-N crotonic acid Chemical compound C\C=C\C(O)=O LDHQCZJRKDOVOX-NSCUHMNNSA-N 0.000 description 1
- XPPKVPWEQAFLFU-UHFFFAOYSA-N diphosphoric acid Chemical compound OP(O)(=O)OP(O)(O)=O XPPKVPWEQAFLFU-UHFFFAOYSA-N 0.000 description 1
- 239000002270 dispersing agent Substances 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 compound CC(=C)C(=O)OCC1CO1 VOZRXNHHFUQHIL-UHFFFAOYSA-N 0.000 description 1
- 230000003993 interaction Effects 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
- 238000002156 mixing Methods 0.000 description 1
- RPQRDASANLAFCM-UHFFFAOYSA-N oxiran-2-ylmethyl prop-2-enoate Chemical compound C=CC(=O)OCC1CO1 RPQRDASANLAFCM-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000003505 polymerization initiator Substances 0.000 description 1
- LLLCSBYSPJHDJX-UHFFFAOYSA-M potassium;2-methylprop-2-enoate Chemical compound [K+].CC(=C)C([O-])=O LLLCSBYSPJHDJX-UHFFFAOYSA-M 0.000 description 1
- 238000012673 precipitation polymerization Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 229940005657 pyrophosphoric acid Drugs 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229940047670 sodium acrylate Drugs 0.000 description 1
- 235000019832 sodium triphosphate Nutrition 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
- UNXRWKVEANCORM-UHFFFAOYSA-N triphosphoric acid Chemical compound OP(O)(=O)OP(O)(=O)OP(O)(O)=O UNXRWKVEANCORM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/14—Magnesium hydroxide
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
Description
本発明は水酸化マグネシウム水分散液の製造法
に関するものである。詳しくは、特定の共重合体
のアルカリ中和物及び水溶性燐酸塩を用いる、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るため
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及び水
溶性燐酸塩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造法、及
びその製造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
製造法は、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(A)（以下、共重合体アルカリ
中和物(A)という。）100部に対して水溶性燐酸塩(B)
が５〜40部の範囲の比率の量での共存下で、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(A)
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(A)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(A)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(A)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(A)の
水溶液PH６〜９の値となる量を用いればよい。
水溶性燐酸塩(B)としては、例えばヘキサメタ燐
酸、トリポリ燐酸あるいはピロリン酸などの燐酸
のアルカリ塩が用いられる。
本発明では、共重合体アルカリ中和物(A)と水溶
性燐酸塩(B)とを必ず併用しなければならない。本
発明の優れた効果は、共重合体アルカリ中和物(A)
と水溶性燐酸塩(B)とが一体不可分の関係で作用し
あうことにより初めて得られるものであり、それ
ぞれ単独では決して得ることが出来ないものであ
る。
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。
本発明に基づいて水酸化マグネシウム水分散液
を製造するには、共重合体アルカリ中和物(A)及び
水溶性燐酸塩(B)の前記の特定の比率での共存下に
水酸化マグネシウム微粉末を水に分散させればよ
い。このような方法としては、例えば水酸化マグ
ネシウム微粉末と水とからなるペースト状組成物
に共重合体アルカリ中和物(A)と水溶性燐酸塩(B)と
の混合物を加えて撹拌混合する方法、あるいは共
重合体アルカリ中和物(A)と水溶性燐酸塩(B)とを溶
解した水溶液中に水酸化マグネシウム微粉末を添
加して撹拌混合する方法等挙げることができる。
しかし、このような共重合体アルカリ中和物(A)、
水溶性燐酸塩(B)及び水酸化マグネシウム微粉末の
添加順序や添加方法により本発明の範囲が制限さ
れるものではない。
このようにして本発明の方法に基づいて得られ
た水酸化マグネシウム水分散液は、従来公知の分
散剤を用いた水酸化マグネシウム水分散液に比し
て著しく低い粘度を示し、分散安定性も良好で粘
度の経時変化が少く、又、加熱処理を受けた場合
でも粘度変化が少いという優れた物性を有してい
る。
以下、参考例、実施例、比較例により本発明を
更に詳しく説明するが、本発明はこれらの例のみ
に制限されるものではない。尚、これらの例中、
％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1235ｇ
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 and a water-soluble phosphate. 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, it is preferable that the magnesium hydroxide be as fine as possible from the viewpoint of the desulfurization reaction rate. Additionally, magnesium hydroxide is generally transported in the form of an aqueous dispersion, but 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 1 μm 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 inventors of the present invention have conducted intensive research and have found that they can industrially produce a highly concentrated aqueous dispersion of magnesium hydroxide by using an alkali-neutralized product of a specific copolymer and a water-soluble phosphate. The present invention was completed by discovering that it can be manufactured. Therefore, an object of the present invention is to provide a method for producing a high concentration and low viscosity aqueous dispersion of fine magnesium hydroxide powder, and a specific alkali-neutralized copolymer used in the production method. It is. That is, the method for producing an aqueous magnesium hydroxide dispersion of the present invention uses an unsaturated monomer (a) selected from the group consisting of hydroxyalkyl acrylate and hydroxyalkyl methacrylate and an unsaturated carboxylic acid (b) as essential components, Unsaturated monomer (a) from 60 to
Within the range of 5 mol% and unsaturated carboxylic acid (b) from 40 to
Water-soluble phosphate per 100 parts of alkali neutralized copolymer (A) (hereinafter referred to as copolymer alkali neutralized product (A)) obtained by using an amount within the range of 95 mol%. (B)
is characterized in that fine magnesium hydroxide powder is dispersed in water in the presence of a proportion of 5 to 40 parts. Copolymer alkali neutralized product (A) used in the present invention
has an unsaturated monomer (a) and an unsaturated carboxylic acid (b) as essential components, and 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. This is a neutralized product of the copolymer obtained using an alkaline substance in an amount ranging from 1. 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 (A) 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%. , these monomers and other copolymerizable monomers can be copolymerized. Examples of such monomers include alkyl acrylates and alkyl methacrylates having an alkyl group having 1 to 4 carbon atoms, glycidyl acrylate,
Examples include glycidyl methacrylate, alkoxyalkyl acrylate and alkoxyalkyl methacrylate having an alkyl group having 1 to 4 carbon atoms, acrylamide, N-methylolacrylamide, and vinyl acetate. There are no particular restrictions on the polymerization method for obtaining the alkali-neutralized copolymer (A) 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. The method for obtaining the alkali-neutralized copolymer (A) of the present invention includes, for example, an unsaturated monomer (a), an unsaturated carboxylic acid (b), and, if necessary, other copolymerizable monomers. A method in which mixed monomers are copolymerized in a lower alcohol by precipitation polymerization, and the resulting copolymer is neutralized with an alkaline substance in an aqueous medium, and an alkali-neutralized product of unsaturated carboxylic acid (b) and unsaturated Examples include a method in which the monomer (a) and, if necessary, other copolymerizable monomers are dropped into an aqueous medium together with a polymerization initiator and copolymerized by heating. 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 the alkaline substance to be used may be such that the copolymer of the present invention is water-soluble, and for this purpose, the amount that makes the aqueous solution of the alkali-neutralized copolymer (A) have a pH value of 6 to 9 is sufficient. good. As the water-soluble phosphate (B), for example, an alkali salt of phosphoric acid such as hexametaphosphoric acid, tripolyphosphoric acid or pyrophosphoric acid is used. In the present invention, the alkali neutralized copolymer (A) and the water-soluble phosphate (B) must be used together. The excellent effect of the present invention is that copolymer alkali neutralized product (A)
It can only be obtained by the inseparable interaction of phosphoric acid and water-soluble phosphate (B), and it is impossible to obtain each separately. As the magnesium hydroxide fine powder used in the present invention, conventionally known powders that are effectively used in the field of desulfurization and the like can be used. In order to produce an aqueous dispersion of magnesium hydroxide according to the present invention, a fine amount of magnesium hydroxide is added in the coexistence of the alkali neutralized copolymer (A) and the water-soluble phosphate (B) in the above-mentioned specific ratio. The powder can be dispersed in water. Such a method includes, for example, adding a mixture of alkali neutralized copolymer (A) and water-soluble phosphate (B) to a paste composition consisting of fine magnesium hydroxide powder and water, and stirring and mixing. or a method in which fine magnesium hydroxide powder is added to an aqueous solution of the alkali-neutralized copolymer (A) and the water-soluble phosphate (B) and mixed with stirring.
However, such a copolymer alkali neutralized product (A),
The scope of the present invention is not limited by the order or method of addition of the water-soluble phosphate (B) and fine magnesium hydroxide powder. The magnesium hydroxide aqueous dispersion thus obtained based on the method of the present invention exhibits a significantly lower viscosity than a magnesium hydroxide aqueous dispersion using a conventionally known dispersant, and has low dispersion stability. It has excellent physical properties such that its viscosity changes little over time, and even when subjected to heat treatment, its viscosity changes little. Hereinafter, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples, but the present invention is not limited only to these examples. In addition, among these examples,
% means % by weight, and parts mean parts by weight. Reference example 1 Initial water 1235g in a 6-necked flask with an internal volume of 5 equipped with a reflux condenser, 3 dropping funnels and a thermometer.
was charged and heated to reflux. Next, 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 while the solvent was refluxing. The polymerization reaction was carried out and the mixture was further aged under reflux for 30 minutes to obtain an aqueous solution of the alkali-neutralized copolymer (1). Reference Examples 2 to 4 A polymerization reaction was carried out in the same manner as in Reference Example 1, except that each monomer composition and the amount of water listed in Table 1 were used.
Aqueous solutions of various alkali-neutralized copolymers were obtained.
These copolymer alkali-neutralized products are hereinafter referred to as copolymer alkali-neutralized product (2), copolymer alkali-neutralized product (3), and copolymer alkali-neutralized product (4), respectively.
【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
21.8ｇとり、水187ｇを加え、さらにトリポリ燐
酸ナトリウム0.4ｇを加えて均一に溶解させ、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0.3μ）390
ｇ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％水分散液
を得た。製造直後の水分散液粘度は第２表に示し
た如く141cps（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156cpsであつた。
実施例 ２
参考例２で得た共重合体アルカリ中和物(2)25％
水溶液20.3ｇおよびヘキサメタ燐酸ナトリウム
0.8ｇを用いる他は実施例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。
実施例 ３
参考例３で得た共重合体アルカリ中和物(3)25％
水溶液18.7ｇおよびピロ燐酸カリウム1.6ｇを用
いる他は実施例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。
実施例 ４
参考例４で得た共重合体アルカリ中和物(4)25％
水溶液15.6ｇおよびピロ燐酸カリウム2.3ｇを用
いる他は実施例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
参考例３で得た共重合体アルカリ中和物(3)25％
水溶液23.2ｇのみを用いる他は実施例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 ２
参考例２で得た共重合体アルカリ中和物(2)25％
水溶液12.5ｇおよびピロ燐酸カリウム3.1ｇを用
いる他は実施例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 ３
実施例１で用いたと同様のビーカーに水202ｇ
とヘキサメタリン酸ナトリウム８ｇを入れ、均一
に溶解したのち実施例１で用いたと同様のラボデ
イスパーで撹拌しながら水酸化マグネシウム微粉
末390ｇを約20分間で添加した。添加終了後2000
で15分間撹拌し、水酸化マグネシウム水分散液を
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 ４
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 A comparative copolymer alkali neutralized product was prepared in the same manner as Reference Example 1 except that the initial water amount was 2454 g and the monomer composition was 848 g of 2-hydroxyethyl acrylate and 1548 g of a 25% aqueous solution of potassium methacrylate.
An aqueous solution of (1) was obtained. Example 1 A 25% aqueous solution of the alkali neutralized copolymer (1) obtained in Reference Example 1 was placed in a stainless steel beaker with an internal volume of 1.
Take 21.8g, add 187g of water, further add 0.4g of sodium tripolyphosphate, dissolve uniformly, and stir with Lab Disper (manufactured by Tokushu Kika Co., Ltd.) to dissolve fine magnesium hydroxide powder (primary particle size 0.3μ) 390
g was added in about 20 minutes. At 2000rpm after addition
The mixture was stirred for 15 minutes to obtain a 65% aqueous dispersion of magnesium hydroxide. The viscosity of the aqueous dispersion immediately after production was 141 cps as shown in Table 2 (25°C, B-type viscometer, the same applies below)
It was hot. The viscosity of this aqueous dispersion after being left at 40°C for 14 days was 156 cps. Example 2 Copolymer alkali neutralized product (2) obtained in Reference Example 2 25%
20.3g of aqueous solution and sodium hexametaphosphate
An aqueous dispersion of magnesium hydroxide was prepared in the same manner as in Example 1, except that 0.8 g was used, and the viscosity was measured. The results were as shown in Table 2. Example 3 Copolymer alkali neutralized product (3) obtained in Reference Example 3 25%
An aqueous dispersion of magnesium hydroxide was prepared in the same manner as in Example 1, except that 18.7 g of the aqueous solution and 1.6 g of potassium pyrophosphate were used, and the viscosity was measured. The results were as shown in Table 2. Example 4 Copolymer alkali neutralized product (4) obtained in Reference Example 4 25%
An aqueous dispersion of magnesium hydroxide was prepared in the same manner as in Example 1, except that 15.6 g of the aqueous solution and 2.3 g of potassium pyrophosphate were used, and the viscosity was measured. The results were as shown in Table 2. Comparative Example 1 Copolymer alkali neutralized product (3) obtained in Reference Example 3 25%
An aqueous dispersion of magnesium hydroxide was prepared in the same manner as in Example 1, except that only 23.2 g of the aqueous solution was used, and the viscosity was measured. The results were as shown in Table 2. Comparative Example 2 Copolymer alkali neutralized product (2) obtained in Reference Example 2 25%
An aqueous dispersion of magnesium hydroxide was prepared in the same manner as in Example 1, except that 12.5 g of the aqueous solution and 3.1 g of potassium pyrophosphate were used, and the viscosity was measured. The results were as shown in Table 2. Comparative Example 3 202g of water in the same beaker as used in Example 1
and 8 g of sodium hexametaphosphate were added thereto, and after uniformly dissolving, 390 g of fine magnesium hydroxide powder was added over about 20 minutes while stirring with a lab disper similar to that used in Example 1. 2000 after addition
The mixture was stirred for 15 minutes to produce an aqueous magnesium hydroxide dispersion, and its viscosity was measured. The results were as shown in Table 2. Comparative Example 4 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
％の搬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(A)100部に対して水溶性燐酸塩(B)が
５〜40部の範囲の比率の量での共存下で、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造法。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 the water-soluble phosphate (B) is 5 parts per 100 parts of the alkali neutralized copolymer (A). A method for producing an aqueous magnesium hydroxide dispersion, characterized in that fine magnesium hydroxide powder is dispersed in water in the coexistence of amounts in proportions ranging from ~40 parts.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15061279A JPS5673623A (en) | 1979-11-22 | 1979-11-22 | Manufacture of aqueous magnesium hydroxide dispersion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15061279A JPS5673623A (en) | 1979-11-22 | 1979-11-22 | Manufacture of aqueous magnesium hydroxide dispersion |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5673623A JPS5673623A (en) | 1981-06-18 |
| JPS6156168B2 true JPS6156168B2 (en) | 1986-12-01 |
Family
ID=15500679
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15061279A Granted JPS5673623A (en) | 1979-11-22 | 1979-11-22 | Manufacture of aqueous magnesium hydroxide dispersion |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5673623A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61270214A (en) * | 1985-05-24 | 1986-11-29 | Shin Nippon Kagaku Kogyo Co Ltd | Suspension of magnesium hydroxide and production thereof |
| 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 |
| GB0014519D0 (en) * | 2000-06-15 | 2000-08-09 | Ciba Spec Chem Water Treat Ltd | Stabilised magnesium hydroxide slurries |
| CN102049211A (en) * | 2010-10-26 | 2011-05-11 | 苏州博纳化学科技有限公司 | Organic-inorganic composite dispersing agent as well as preparation method and application thereof |
-
1979
- 1979-11-22 JP JP15061279A patent/JPS5673623A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5673623A (en) | 1981-06-18 |
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