JPH02271925A - Production of transparent spheroidal fine iron oxide particles - Google Patents
Production of transparent spheroidal fine iron oxide particlesInfo
- Publication number
- JPH02271925A JPH02271925A JP9224189A JP9224189A JPH02271925A JP H02271925 A JPH02271925 A JP H02271925A JP 9224189 A JP9224189 A JP 9224189A JP 9224189 A JP9224189 A JP 9224189A JP H02271925 A JPH02271925 A JP H02271925A
- Authority
- JP
- Japan
- Prior art keywords
- iron oxide
- salt
- dried
- fine particles
- particle size
- 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.)
- Granted
Links
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 title claims description 80
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- 239000002245 particle Substances 0.000 title abstract description 24
- 150000003839 salts Chemical class 0.000 claims abstract description 26
- 239000002244 precipitate Substances 0.000 claims abstract description 10
- 238000001035 drying Methods 0.000 claims abstract description 9
- 239000003513 alkali Substances 0.000 claims abstract description 6
- 238000005406 washing Methods 0.000 claims abstract description 4
- 239000010419 fine particle Substances 0.000 claims description 24
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 8
- 239000007864 aqueous solution Substances 0.000 claims description 8
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 3
- 229960004887 ferric hydroxide Drugs 0.000 claims description 3
- IEECXTSVVFWGSE-UHFFFAOYSA-M iron(3+);oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Fe+3] IEECXTSVVFWGSE-UHFFFAOYSA-M 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 229910001854 alkali hydroxide Inorganic materials 0.000 claims description 2
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims description 2
- 229910021529 ammonia Inorganic materials 0.000 claims description 2
- 239000002002 slurry Substances 0.000 abstract description 16
- 239000000843 powder Substances 0.000 abstract description 12
- 238000006243 chemical reaction Methods 0.000 abstract description 11
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 abstract description 5
- 238000009826 distribution Methods 0.000 abstract description 5
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical group [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 abstract description 5
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 abstract description 4
- 235000011114 ammonium hydroxide Nutrition 0.000 abstract description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 abstract description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 abstract 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 abstract 2
- FLTRNWIFKITPIO-UHFFFAOYSA-N iron;trihydrate Chemical compound O.O.O.[Fe] FLTRNWIFKITPIO-UHFFFAOYSA-N 0.000 abstract 2
- 239000000047 product Substances 0.000 abstract 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 abstract 1
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 abstract 1
- 235000017550 sodium carbonate Nutrition 0.000 abstract 1
- 235000011121 sodium hydroxide Nutrition 0.000 abstract 1
- 238000000034 method Methods 0.000 description 10
- 239000000243 solution Substances 0.000 description 7
- 239000012670 alkaline solution Substances 0.000 description 5
- 239000012266 salt solution Substances 0.000 description 5
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000000049 pigment Substances 0.000 description 4
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000003973 paint Substances 0.000 description 3
- 241000549556 Nanos Species 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 150000003841 chloride salts Chemical class 0.000 description 2
- 238000004040 coloring Methods 0.000 description 2
- 239000002537 cosmetic Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 229910052595 hematite Inorganic materials 0.000 description 2
- 239000011019 hematite Substances 0.000 description 2
- 239000001034 iron oxide pigment Substances 0.000 description 2
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000012785 packaging film Substances 0.000 description 2
- 229920006280 packaging film Polymers 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 235000019270 ammonium chloride Nutrition 0.000 description 1
- 239000003957 anion exchange resin Substances 0.000 description 1
- 239000003945 anionic surfactant Substances 0.000 description 1
- 235000013361 beverage Nutrition 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- -1 salt compound Chemical class 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 210000004243 sweat Anatomy 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/02—Oxides; Hydroxides
- C01G49/06—Ferric oxide [Fe2O3]
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/30—Particle morphology extending in three dimensions
- C01P2004/32—Spheres
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/54—Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/60—Optical properties, e.g. expressed in CIELAB-values
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Nanotechnology (AREA)
- Inorganic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Composite Materials (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Compounds Of Iron (AREA)
Abstract
Description
〔産業上の利用分野]
本発明は各種メタリック塗装、フィルム着色用顔料およ
び酸化鉄の紫外線吸収能を利用した食品包装フィルム又
は容器用に有用な透明酸化鉄微粒子の製造方法に関する
ものである。[Industrial Application Field] The present invention relates to a method for producing transparent iron oxide fine particles useful for various metallic coatings, film coloring pigments, and food packaging films or containers that utilize the ultraviolet absorption ability of iron oxide.
【従来の技術]
酸化鉄微粒子粉末は塗料用顔料粉末として広(利用され
ており、隠ぺい力や着色力を目的とする場合、顔料とし
ての最適粒子径は、0.2〜0.4μIの範囲になるが
、平均粒子径が0,1μm以下になると隠ぺい力が急激
に低下して透明性となる、これは1粒子が光の波長の%
以下となって散乱と回折現象が起こるためであると言わ
れている。
この現象を利用して透明性を付与した酸化鉄顔料が研究
されている。
これまで酸化鉄微粒子粉末の製造方法は数多(報告され
ている。例えば、1)微細な含水酸化鉄を製造し、それ
を加熱脱水して酸化鉄微粒子を得る方法(特公昭51−
21640.特公昭52−13528、特公昭62−4
0293、特商昭6l−163121)、2)微細なマ
グネタイトを製造し、それを加熱して酸化鉄微粒子を得
る方法(特公昭54−7280.特開昭61−2322
25)、3)含水酸化鉄(主にa −Fe00H1β−
Fe00H)をオートクレーブ中で加熱処理し。
酸化鉄微粒子を得る方法(特開昭58−20733、特
開昭63−162535)、4)第二鉄塩化合物の水溶
液を中和反応後、オートクレーブ中で加熱処理し酸化鉄
微粒子を得る方法(特公昭45−18372、特開昭6
2−216919)、5)第二鉄塩にアルカリを添加し
て沈殿させ、口過洗浄後それを乾燥させることにより針
状酸化鉄微粒子を得る方法(特開昭63−79726)
、6)第二鉄塩溶液中に陰イオン交換樹脂を加えて水和
酸化鉄ゾルとし、これに陰イオン性界面活性剤を添加し
て凝集させ、有機溶媒中に分散させた後、蒸発還流して
酸化鉄微粒子を得る方法(特公昭59−4452)など
がある。
〔発明が解決しようとする課題l
上記の様な従来の酸化鉄微粒子では、含水酸化鉄を加熱
脱水して酸化鉄微粒子を得る場合、少なくとも250℃
以上の熱処理が必要であり、マグネタイトを熱処理して
酸化鉄微粒子を得る場合は400℃以上の温度が必要と
なり、このような焼成工程のある製造法では焼成時に凝
集が起こり、プラスチック、塗料などのビヒクル中に一
次粒子の粒径を保ちながら分散させることが困難である
。
また、オートクレーブを用いた製造法では、酸化鉄微粒
子の平均粒径を0.1gm以下にするのは困難であり、
透明酸化鉄微粒子を製造し難い。
また、特開昭63−79726で得られる粒子や、含水
酸化鉄を原料にして(専られな酸化鉄微粒子の形状は針
状をしているが、針状粒子はど吸油量が多(、分散性も
悪く透明性も十分でない。
また、特公昭51−12318では長軸:短軸=5=1
以下の紡錘状粒子の微細な酸化鉄顔料の製造法の記載が
あるが透明度は必ずしも満足できるものではない。
[課題を解決するための手段1
本発明は、形状が球状で粒度分布が狭く、透明性5分散
性が極めて優れた透明酸化鉄微粒子を製造する方法を検
3:tシた結果、次の製造法を見出した。すなわち、第
二鉄塩水溶液中に水酸化アルカリ、炭酸アルカリ、アン
モニアのうち少なくとも種をpH値が6〜10になるよ
うに添加し、その際50℃以下で反応させ、水酸化第二
鉄の沈澱物および塩を生成させた後、該生成塩を含有し
た状態で乾燥し、酸化鉄を生成させた後、洗浄し乾燥す
ることを特徴とする透明球状酸化鉄微粒子の製造方法で
ある。
この方法により造られる透明球状酸化鉄微粒子は平均粒
子径として0.旧〜0.Iu+mで、粒子の長短径比は
0.7以上の球状の形状を有したものである。
本発明に用いられる第二鉄塩としては、硝酸塩、硫酸塩
、塩化物等があるが、分散性の極めて優れた酸化鉄微粒
子を得るには塩化物が特に望ましい。この第二鉄塩溶液
のpHl整をするためのアルカリ溶液としては、例えば
、N a OII、KOJI、NagCOx、 に2C
口3、N)1.0)1. NH3を使用することがで
きるが、結晶性のよい酸化鉄粒子を得るには炭酸アルカ
リ、アンモニア水またはガスが好ましい。
アルカリ溶液を添加し、反応させる温度は、高温になる
につれて粒径が粗大化し、低温で反応させる程、微細化
するため、粒径0.111m以下の透明微粒子にするた
めには、50℃以下でなければならない。より好ましい
反応温度は30℃以下であり、アルカリ溶液がNagC
Oxの場合には、10℃以下がより好ましい。
反応温度の下限は、溶液反応であるため氷点である。
この様にして溶液のpl+を6〜IOに調整する。
pHがIOを超える場合最終生成物に含水酸化鉄が混在
し、pnが6未満の場合、生成した酸化鉄の粒径は、0
.3μ−を超え粒度分布も広くなり、透明性に劣り透明
顔料としては望ましくない。また、反応は、アルカリ溶
液中に第二鉄塩溶液を添加しても、第二鉄塩溶液中にア
ルカリ溶液を添加してもよい。この時攪拌を行って溶液
を均一化し沈澱を生じさせることが望ましい。
また、第二鉄塩溶液中に水と溶解性をもつ低級アルコー
ル等の有機溶剤を含有していてもよい。
pH値を6〜10にして、生成した水酸化第二鉄の沈澱
物を汗通は口過する。
この沈澱物を生成塩の存在下で乾燥する。
ここが本発明において最も重要な点であり、特開昭63
−79726の従来技術と異なり、生成塩の存在下でな
いと球状酸化鉄は生成しない。生成塩の存在下で乾燥す
るために沈澱物の洗浄は行わすうにそのまま口過する。
口過は公知の方法でよい(例えば吸引口過)、得られた
ケーキには原料濃度、口過法の違いで、乾燥粉換算で2
0〜60wt%の生成塩が含まれている。そして生成塩
を含んだケーキをそのまま乾燥することにより、酸化鉄
微粒子が生成する。口過ケーキの乾燥粉換算での含塩率
が20wt%未満になると酸化鉄が生じにくくなるので
、その時は塩を後から添加してもよい。
通常は30wt%以上あることが好ましい。
この時の塩の種類としては、原料溶液とアルカリの選択
によりNaC1,KCI、NaNOs、KNO,、Na
2COs、K、S04、NH,C1,fNH41tsO
,、NH4N0.、Na2COs、(N)+41 *c
oz等があるが、NH,CI、 Na(:l。
MCIが好ましい、生成塩と含塩率を増加するために添
加する塩は同一である必要はない。
沈澱物生成後、口過することな(スラリー状態で乾燥し
ても本発明の目的は達成できる。
乾燥法には特に制限はないが、凝集を防ぐため乾燥温度
は300℃以下が望ましい、その後、生成塩等の不純物
を除去するためにこの乾燥粉を洗浄する。洗浄は塩が除
去できればどんな方法でも構わない。
本発明により得られた透明酸化鉄微粒子粉末は、透明性
に優れ、球状であるため微細ではあるが分散性にも優れ
ているため、PETやアクリロニトリル系等の樹脂中に
分散させて、飲料用、医薬用、化粧品用樹脂ボトル、食
品包装フィルム、メタリック塗装等の用途があり、また
化粧品、触媒、吸着剤等に使用することも可能である。
【実施例]
以下、本発明を実施例をもって説明する。
実施例1
0.5mo1/ffのFeC15水溶液60[1mlに
25%のアンモニア水溶液を添加した。この時の反応温
度は10℃で、スラリーのpnをpHメータで調節して
、スラリーのpHが7.0になるように添加した。この
スラリーを10℃で1時間撹拌した後吸引口過し、12
0℃で乾燥した。その後、塩化アンモニウムを除去する
ため洗浄し、再び乾燥した。得られた乾燥粉はX線回折
の測定の結果、ヘマタイト構造を有していた。SEM観
察の結果、ヘマタイトの形状は球形で粒径は0.05μ
lできわめて粒度分布がシャープであった。
比較例1
0.5 mol/ I2のFeC11水溶液600m1
に25%のアンモニア水溶液を添加した。この時の反応
温度は10℃で、スラリーのpIIをpiメータで調節
して、スラリーのpIIが7.0になるように添加した
。このスラリーを10℃で1時間撹拌した後、水洗を行
い吸引口過し、 120℃で乾燥した。得られた乾燥粉
はX線回折の結果、非晶質でヘマタイト構造は有してい
なかった。
比較例2
0.5 mol/ 12のFe(:Is水溶液600m
1に1.0 mol/I2炭酸ナトリウム水溶液を添加
した。この時の反応温度は80℃で、スラリーのpHを
pHメータで調節L/ 7 、25 ’)−(7)pH
が7゛0になるように添加し・また、このスラリーを8
0℃で1時間撹拌した後吸引口過し、 120℃で乾燥
した。得られた乾燥粉はX線回折の結果、β−Fe00
11構造を有していた。
比較例3
0.5 mol/ gのFeC15水溶液600a+1
に25%のアン・モニア水溶液を10℃で添加した。こ
の時スラリーのpHを9Hメータで調節して、スラリー
のpiが11.0になるように添加した。このスラリー
を10℃で1時間撹拌した後吸引口遇し、 12G’c
で乾燥した。得られた乾燥粉はXa回折の結果、ヘマタ
イトとα−Fe00H構造が混在していた。
【発明の効果】
本発明の透明酸化鉄微粒子の製造方法によれば、粒度分
布が狭い0.1μ厘以下の酸化鉄を簡便に製造すること
ができ、しかも、球形である酸化鉄微粒子のため、塗料
の構造ではビヒクル中への分散が良好であり透明性のす
ぐれた塗膜を得ることが可能となる。[Prior art] Iron oxide fine particle powder is widely used as a pigment powder for paints, and when the purpose is to improve hiding power or coloring power, the optimum particle size as a pigment is in the range of 0.2 to 0.4 μI. However, when the average particle size becomes 0.1 μm or less, the hiding power decreases rapidly and becomes transparent, which means that one particle is % of the wavelength of light.
This is said to be due to the following scattering and diffraction phenomena occurring. Iron oxide pigments that use this phenomenon to impart transparency are being researched. Until now, there have been many methods for producing fine iron oxide particles (for example, 1) a method of producing fine hydrated iron oxide and heating and dehydrating it to obtain iron oxide fine particles (Japanese Patent Publication No. 51-1989).
21640. Special Publication No. 52-13528, Special Publication No. 62-4
0293, Japanese Patent Publication No. 61-163121), 2) Method of producing fine magnetite and heating it to obtain iron oxide fine particles (Japanese Patent Publication No. 54-7280, Japanese Patent Publication No. 61-2322)
25), 3) Hydrous iron oxide (mainly a -Fe00H1β-
Fe00H) was heat-treated in an autoclave. A method for obtaining iron oxide fine particles (JP-A-58-20733, JP-A-63-162535); 4) A method for obtaining iron oxide fine particles by neutralizing an aqueous solution of a ferric salt compound and then heat-treating it in an autoclave ( Special Publication No. 45-18372, Special Publication No. 6
2-216919), 5) A method for obtaining acicular iron oxide fine particles by adding an alkali to ferric salt to precipitate it, and drying it after washing the mouth (Japanese Unexamined Patent Publication No. 63-79726)
, 6) Add an anion exchange resin to a ferric salt solution to obtain a hydrated iron oxide sol, add an anionic surfactant to this to coagulate it, disperse it in an organic solvent, and then evaporate and reflux. There is a method for obtaining iron oxide fine particles (Japanese Patent Publication No. 59-4452). [Problems to be Solved by the Invention 1] In the conventional iron oxide fine particles as described above, when iron oxide fine particles are obtained by heating and dehydrating hydrous iron oxide, the temperature is at least 250°C.
The above heat treatment is necessary, and when heat-treating magnetite to obtain iron oxide fine particles, a temperature of 400°C or higher is required, and in manufacturing methods that include such a firing step, agglomeration occurs during firing, which can cause damage to plastics, paints, etc. It is difficult to disperse primary particles in a vehicle while maintaining their particle size. In addition, in the production method using an autoclave, it is difficult to reduce the average particle size of iron oxide fine particles to 0.1 gm or less,
It is difficult to produce transparent iron oxide fine particles. In addition, particles obtained in JP-A No. 63-79726 and hydrated iron oxide are used as raw materials (the shape of iron oxide fine particles is acicular, but acicular particles have a high oil absorption capacity). Dispersibility is poor and transparency is not sufficient. Also, in Japanese Patent Publication No. 51-12318, major axis: minor axis = 5 = 1
Although the following method for producing fine iron oxide pigments with spindle-shaped particles is described, the transparency is not necessarily satisfactory. [Means for Solving the Problems 1] The present invention has investigated a method for producing transparent iron oxide fine particles that are spherical in shape, have a narrow particle size distribution, and have extremely excellent transparency and dispersibility. Found a manufacturing method. That is, at least one species among alkali hydroxide, alkali carbonate, and ammonia is added to an aqueous solution of ferric salt so that the pH value becomes 6 to 10, and the reaction is carried out at 50°C or less to form ferric hydroxide. This is a method for producing transparent spherical iron oxide fine particles, which is characterized in that after a precipitate and a salt are generated, they are dried in a state containing the generated salt, and after iron oxide is generated, they are washed and dried. The transparent spherical iron oxide fine particles produced by this method have an average particle diameter of 0. Old ~ 0. Iu+m, the particle has a spherical shape with a length-to-width ratio of 0.7 or more. Ferric salts used in the present invention include nitrates, sulfates, chlorides, etc., but chlorides are particularly desirable in order to obtain iron oxide fine particles with extremely excellent dispersibility. Examples of alkaline solutions for adjusting the pH of this ferric salt solution include NaOII, KOJI, NagCOx, and 2C.
Mouth 3, N) 1.0) 1. Although NH3 can be used, alkali carbonate, aqueous ammonia or gas are preferred in order to obtain iron oxide particles with good crystallinity. The temperature at which the alkaline solution is added and reacted should be 50°C or lower in order to obtain transparent fine particles with a particle size of 0.111 m or less, because the higher the temperature, the coarser the particle size, and the lower the reaction temperature, the finer the particle size. Must. A more preferable reaction temperature is 30°C or lower, and the alkaline solution is NagC
In the case of Ox, the temperature is more preferably 10°C or less. The lower limit of the reaction temperature is the freezing point because it is a solution reaction. In this way, the pl+ of the solution is adjusted to 6-IO. When the pH exceeds IO, the final product contains hydrated iron oxide, and when pn is less than 6, the particle size of the produced iron oxide is 0.
.. If it exceeds 3μ, the particle size distribution becomes broad, and the transparency is poor, making it undesirable as a transparent pigment. Further, the reaction may be carried out by adding a ferric salt solution to an alkaline solution, or by adding an alkaline solution to a ferric salt solution. At this time, it is desirable to stir the solution to homogenize the solution and form a precipitate. Further, the ferric salt solution may contain an organic solvent such as a lower alcohol that is soluble in water. The pH value is adjusted to 6 to 10, and the resulting ferric hydroxide precipitate is passed through the mouth by a sweat connoisseur. This precipitate is dried in the presence of the formed salt. This is the most important point in the present invention, and is
Unlike the prior art of -79726, spherical iron oxide is not produced unless the produced salt is present. Since the precipitate is dried in the presence of the formed salt, the precipitate is washed and passed through the mouth as it is. The filtration may be carried out by any known method (for example, suction filtration), but depending on the raw material concentration and the filtration method, the resulting cake may have a dry powder content of 2.
Contains 0 to 60 wt% of produced salt. Then, by drying the cake containing the produced salt as it is, iron oxide fine particles are produced. When the salt content of the pass cake in terms of dry powder is less than 20 wt%, iron oxide is less likely to be produced, so in that case salt may be added later. Usually, it is preferable that the content is 30 wt% or more. The type of salt at this time is NaCl, KCI, NaNOs, KNO, NaCl, KCI, NaNOs, KNO, Na
2COs, K, S04, NH, C1, fNH41tsO
,,NH4N0. , Na2COs, (N)+41 *c
oz, etc., but NH, CI, Na (:l. MCI is preferred. The salt produced and the salt added to increase the salt content do not need to be the same. After forming a precipitate, pass through the mouth. (The purpose of the present invention can be achieved even by drying in a slurry state. There are no particular restrictions on the drying method, but the drying temperature is preferably 300°C or less to prevent agglomeration. After that, impurities such as formed salts are removed. The dry powder is washed for this purpose.Any washing method may be used as long as the salt can be removed.The transparent iron oxide fine particle powder obtained by the present invention has excellent transparency and is spherical, so although it is fine, it has good dispersibility. Because of its excellent properties, it can be dispersed in resins such as PET and acrylonitrile and used in resin bottles for beverages, pharmaceuticals, and cosmetics, food packaging films, metallic coatings, etc. It is also used in cosmetics, catalysts, adsorbents, etc. [Example] The present invention will be explained below with reference to Examples. Example 1 A 25% ammonia aqueous solution was added to 60 [1 ml] of a 0.5 mo1/ff aqueous FeC15 solution. The reaction temperature was 10°C, and the pn of the slurry was adjusted with a pH meter, and the slurry was added so that the pH of the slurry was 7.0.The slurry was stirred at 10°C for 1 hour, passed through a suction port, and
It was dried at 0°C. Thereafter, it was washed to remove ammonium chloride and dried again. As a result of X-ray diffraction measurement, the obtained dry powder had a hematite structure. As a result of SEM observation, the shape of hematite is spherical and the particle size is 0.05μ.
The particle size distribution was extremely sharp. Comparative Example 1 0.5 mol/I2 FeC11 aqueous solution 600ml
A 25% ammonia aqueous solution was added to the solution. The reaction temperature at this time was 10° C., and the pII of the slurry was adjusted using a pi meter, and the slurry was added so that the pII of the slurry was 7.0. This slurry was stirred at 10°C for 1 hour, washed with water, passed through a suction port, and dried at 120°C. As a result of X-ray diffraction, the obtained dry powder was amorphous and did not have a hematite structure. Comparative Example 2 0.5 mol/12 Fe(:Is aqueous solution 600 m
1.0 mol/I2 aqueous sodium carbonate solution was added to 1. The reaction temperature at this time was 80°C, and the pH of the slurry was adjusted using a pH meter.
Add this slurry so that it becomes 7゛0.
After stirring at 0°C for 1 hour, the mixture was filtered through a suction port and dried at 120°C. As a result of X-ray diffraction, the obtained dry powder was found to be β-Fe00
It had 11 structures. Comparative Example 3 0.5 mol/g FeC15 aqueous solution 600a+1
A 25% aqueous ammonia solution was added at 10°C. At this time, the pH of the slurry was adjusted using a 9H meter, and the slurry was added so that its pi was 11.0. This slurry was stirred at 10°C for 1 hour, then exposed to a suction port and heated to 12G'c.
It was dried. As a result of Xa diffraction, the obtained dry powder contained a mixture of hematite and α-Fe00H structures. Effects of the Invention According to the method for producing transparent iron oxide fine particles of the present invention, iron oxide having a narrow particle size distribution of 0.1 μm or less can be easily produced, and since the iron oxide fine particles are spherical, The structure of the paint allows for good dispersion in the vehicle, making it possible to obtain a coating film with excellent transparency.
Claims (1)
ンモニアのうち少なくとも一種をpH値が6〜10にな
るように添加し、50℃以下で反応させ、水酸化第二鉄
の沈澱物および塩を生成させた後、該生成塩を含有した
状態で乾燥し、酸化鉄を生成させた後、洗浄し乾燥する
ことを特徴とする透明球状酸化鉄微粒子の製造方法。At least one of alkali hydroxide, alkali carbonate, and ammonia is added to the ferric salt aqueous solution so that the pH value becomes 6 to 10, and the mixture is reacted at 50°C or lower to form a precipitate of ferric hydroxide and salt. 1. A method for producing transparent spherical iron oxide fine particles, which comprises: producing iron oxide, followed by drying in a state containing the produced salt, producing iron oxide, washing and drying.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9224189A JPH02271925A (en) | 1989-04-12 | 1989-04-12 | Production of transparent spheroidal fine iron oxide particles |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9224189A JPH02271925A (en) | 1989-04-12 | 1989-04-12 | Production of transparent spheroidal fine iron oxide particles |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH02271925A true JPH02271925A (en) | 1990-11-06 |
JPH0577613B2 JPH0577613B2 (en) | 1993-10-27 |
Family
ID=14048939
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP9224189A Granted JPH02271925A (en) | 1989-04-12 | 1989-04-12 | Production of transparent spheroidal fine iron oxide particles |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH02271925A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11181336A (en) * | 1997-09-30 | 1999-07-06 | Sumitomo Metal Mining Co Ltd | Coating fluid for permselective membrane, permselective membrane, and multi layered permselective membrane |
CN107532064A (en) * | 2015-06-26 | 2018-01-02 | M技术株式会社 | The manufacture method of ultra-violet protecting agent composition and by this method and the ultra-violet protecting agent composition that obtains |
CN110422886A (en) * | 2019-08-23 | 2019-11-08 | 上海新禹固废处理有限公司 | A kind of preparation method of hydrated ferric oxide |
-
1989
- 1989-04-12 JP JP9224189A patent/JPH02271925A/en active Granted
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11181336A (en) * | 1997-09-30 | 1999-07-06 | Sumitomo Metal Mining Co Ltd | Coating fluid for permselective membrane, permselective membrane, and multi layered permselective membrane |
CN107532064A (en) * | 2015-06-26 | 2018-01-02 | M技术株式会社 | The manufacture method of ultra-violet protecting agent composition and by this method and the ultra-violet protecting agent composition that obtains |
EP3315575A4 (en) * | 2015-06-26 | 2019-01-09 | M. Technique Co., Ltd. | Method for producing ultraviolet protective agent composition, and ultraviolet protective agent composition obtained thereby |
CN107532064B (en) * | 2015-06-26 | 2021-03-16 | M技术株式会社 | Method for producing ultraviolet protective agent composition and ultraviolet protective agent composition obtained by the method |
US11629063B2 (en) | 2015-06-26 | 2023-04-18 | M. Technique Co., Ltd. | Method of producing ultraviolet protective agent composition, and ultraviolet protective agent composition obtained thereby |
CN110422886A (en) * | 2019-08-23 | 2019-11-08 | 上海新禹固废处理有限公司 | A kind of preparation method of hydrated ferric oxide |
Also Published As
Publication number | Publication date |
---|---|
JPH0577613B2 (en) | 1993-10-27 |
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