JPH09165531A - Production of heat resisting hydrate iron oxide pigment - Google Patents
Production of heat resisting hydrate iron oxide pigmentInfo
- Publication number
- JPH09165531A JPH09165531A JP34804795A JP34804795A JPH09165531A JP H09165531 A JPH09165531 A JP H09165531A JP 34804795 A JP34804795 A JP 34804795A JP 34804795 A JP34804795 A JP 34804795A JP H09165531 A JPH09165531 A JP H09165531A
- Authority
- JP
- Japan
- Prior art keywords
- iron oxide
- yellow iron
- oxide hydroxide
- value
- particles
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/22—Compounds of iron
- C09C1/24—Oxides of iron
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、分散性が優れており、
しかも、耐熱性が向上しているとともに、耐熱性改善処
理工程の前後における色相の変化が小さい耐熱性黄色含
水酸化鉄顔料の製造法に関するものである。The present invention has excellent dispersibility,
Moreover, the present invention relates to a method for producing a heat-resistant yellow iron oxide hydroxide pigment that has improved heat resistance and a small change in hue before and after the heat resistance improvement treatment step.
【０００２】[0002]
【従来の技術】黄色顔料は、樹脂やビヒクル中に分散さ
せて、樹脂、塗料、印刷インキ、道路アスファルトを製
造する際の着色顔料として広く使用されている。黄色は
交通上の規則や警戒を表す色であることから、殊に、道
路アスファルト用や路面表示塗料（トラフィックペイン
ト）用着色顔料としての用途が拡大している。BACKGROUND OF THE INVENTION Yellow pigments are widely used as color pigments when they are dispersed in resins or vehicles to produce resins, paints, printing inks and road asphalt. Since yellow is a color that represents traffic rules and vigilance, its use is expanding especially as a color pigment for road asphalt and road surface paint (traffic paint).
【０００３】黄色顔料は、作業能率の面から樹脂やビヒ
クル中における分散性が優れていることはもちろん、耐
熱性が優れていることが要求される。The yellow pigment is required to have excellent heat resistance as well as excellent dispersibility in a resin or vehicle in terms of work efficiency.
【０００４】黄色顔料としては、従来から、クロム酸
鉛、クロム酸ストロンチウム、硫化カドミウム、含水酸
化鉄等が知られており、広く使用されている。As the yellow pigment, lead chromate, strontium chromate, cadmium sulfide, iron oxide hydrate, etc. have been conventionally known and widely used.
【０００５】上記クロム酸鉛、クロム酸ストロンチウ
ム、硫化カドミウム等は、耐熱性に優れているため、樹
脂、塗料、印刷インキ等の着色顔料として広く使用され
ているが、有毒性、発癌性を有することから、国民の健
康、衛生、安全性の観点から、また、環境汚染防止の観
点から代替黄色顔料が強く要求されている。Since the above-mentioned lead chromate, strontium chromate, cadmium sulfide, etc. are excellent in heat resistance, they are widely used as coloring pigments for resins, paints, printing inks, etc., but they have toxicity and carcinogenicity. Therefore, there is a strong demand for alternative yellow pigments from the viewpoints of people's health, hygiene and safety, and also from the viewpoint of preventing environmental pollution.
【０００６】含水酸化鉄粒子は、無毒であり、国民の健
康、衛生、安全性の観点から、また、環境汚染防止の観
点から優れたものではあるが、耐熱性の点で劣っている
という問題がある。The iron oxide hydroxide particles are non-toxic and excellent from the viewpoint of health, hygiene and safety of the people and from the viewpoint of preventing environmental pollution, but they are inferior in heat resistance. There is.
【０００７】即ち、含水酸化鉄粒子は、Ｆｅ2 Ｏ3 ・ｎ
Ｈ2 Ｏで示される通り、結晶水を有しており、加熱温度
を昇温させていくと、一般に２００℃前後で脱水が開始
し始め、やがて２３０℃程度の温度で赤褐色のヘマタイ
ト（α−Ｆｅ2 Ｏ3 ）に変態する。That is, the iron oxide hydroxide particles are Fe 2 O 3 .n
As shown by H 2 O, it has water of crystallization, and when the heating temperature is raised, generally, dehydration starts around 200 ° C., and eventually reddish brown hematite (α- It transforms to Fe 2 O 3 ).
【０００８】そのため、通常２００℃以上の高温度で成
形加工されているポリエチレン、ポリプロピレン、スチ
レン重合体、ポリアミド、ポリオレフィン、ＡＢＳなど
の熱可塑性樹脂や、施工時に２００〜２６０℃で加熱し
たり、溶融して使用される路面表示用塗料（トラフィッ
クペイント）に含水酸化鉄粒子を使用することは困難で
あった。Therefore, thermoplastic resins such as polyethylene, polypropylene, styrene polymers, polyamides, polyolefins and ABS, which are usually molded and processed at a high temperature of 200 ° C. or higher, or heated at 200 to 260 ° C. or melted during construction. It was difficult to use the iron oxide hydroxide particles in the road surface display paint (traffic paint) that is used in the past.
【０００９】そこで、含水酸化鉄粒子の耐熱性を向上さ
せるために種々の処理を施すことが行われているが、耐
熱性改善処理工程の前後で色相の変化が大きいと、着色
顔料の命ともいうべき色相面からの製品設計が困難とな
ることから、耐熱性改善処理工程の前後における色相の
変化ができるだけ小さいことが要求される。Therefore, various treatments have been carried out in order to improve the heat resistance of the iron oxide hydroxide particles. However, if the hue changes greatly before and after the heat resistance improving treatment step, the life of the color pigment may be increased. Since it is difficult to design a product from the viewpoint of hue, it is required that the change in hue before and after the heat resistance improvement treatment step is as small as possible.
【００１０】従来、含水酸化鉄粒子の耐熱性を向上させ
るための改善が種々試みられており、（１）含水酸化鉄
粒子をオートクレーブを用いて水又はアルカリ水溶液中
で水熱処理する方法（特公昭５３−２８１５８号公報
等）、（２）含水酸化鉄粒子の粒子表面をアルミニウム
化合物、ケイ素化合物等で被覆したり、含有、固溶させ
る方法（特公平６−１７２３７号公報等）、（３）上記
（１）の方法と（２）の方法を組み合わせる方法（特公
昭４９−１６５３１号公報、特公昭５４−７２９３号公
報、特公昭５５−８４６２号公報、特開昭５７−５７７
５５号公報等）等が知られている。Various attempts have been made so far to improve the heat resistance of iron oxide hydroxide particles, and (1) a method of hydrothermally treating iron oxide hydroxide particles in water or an alkaline aqueous solution using an autoclave (Japanese Patent Publication No. 53-28158, etc.), (2) A method of coating the particle surface of iron oxide hydroxide particles with an aluminum compound, a silicon compound, etc., or containing and forming a solid solution (Japanese Patent Publication No. 6-17237 etc.), (3) A method in which the method (1) and the method (2) are combined (Japanese Patent Publication No. 49-16531, Japanese Patent Publication No. 54-7293, Japanese Patent Publication No. 55-8462, and Japanese Patent Laid-Open No. 57-577).
No. 55, etc.) are known.
【００１１】[0011]
【発明が解決しようとする課題】分散性が優れており、
しかも、耐熱性が向上しているとともに、耐熱性改善処
理工程の前後における色相の変化が小さい黄色含水酸化
鉄粒子は、現在、最も要求されているところであるが、
これら諸特性を有する黄色含水酸化鉄顔料は、未だ得ら
れていない。The dispersibility is excellent,
Moreover, while the heat resistance is improved, yellow iron oxide hydroxide particles having a small change in hue before and after the heat resistance improvement treatment step are currently most demanded,
A yellow iron oxide hydroxide pigment having these characteristics has not been obtained yet.
【００１２】即ち、前出（１）の方法による処理を行っ
た黄色含水酸化鉄粒子は、耐熱性が向上したものではあ
るが、粒子の形態や粒度分布が耐熱性改善処理工程の前
後で大きく変化し、その結果、色相の変化が大きいもの
であった。That is, although the yellow iron oxide hydroxide particles treated by the above-mentioned method (1) have improved heat resistance, the morphology and particle size distribution of the particles are large before and after the heat resistance improving treatment step. As a result, there was a large change in hue.
【００１３】前出（２）の方法による処理を行った黄色
含水酸化鉄粒子は、色相の変化は小さいものではある
が、黄色含水酸化鉄粒子を凝集したままでアルミニウム
化合物等で被覆しているため、分散性が悪く、また、耐
熱性も不十分なものであった。Although the yellow iron oxide hydroxide particles treated by the method of the above (2) have a small change in hue, the yellow iron oxide hydroxide particles are coated with an aluminum compound or the like in the state of being agglomerated. Therefore, the dispersibility was poor and the heat resistance was insufficient.
【００１４】前出（３）の方法による処理を行った黄色
含水酸化鉄粒子は、耐熱性が向上したものではあるが、
前出（１）の方法と同様に耐熱性改善処理工程の前後に
おける色相の変化が大きいものである。Although the yellow iron oxide hydroxide particles treated by the method (3) above have improved heat resistance,
Similar to the method (1) above, the hue changes largely before and after the heat resistance improvement treatment step.
【００１５】そこで、本発明は、分散性が優れており、
しかも、耐熱性が向上しているとともに、耐熱性改善処
理工程の前後における色相の変化が小さい黄色含水酸化
鉄粒子を得ることを技術的課題とする。Therefore, the present invention has excellent dispersibility,
Moreover, it is a technical subject to obtain yellow iron oxide hydroxide particles whose heat resistance is improved and whose hue changes before and after the heat resistance improving treatment step are small.
【００１６】[0016]
【課題を解決する為の手段】前記技術的課題は、次の通
りの本発明によって達成できる。The above technical object can be achieved by the present invention as described below.
【００１７】即ち、本発明は、黄色含水酸化鉄粒子を、
ｐＨ値が１０以上のアルカリ性水溶液中で加熱処理した
後、濾別、水洗して可溶性硫酸塩をＳＯ4 換算で２００
０ｐｐｍ以下とする工程とｐＨ値が４以下の酸性水溶液
中で加熱処理した後、濾別、水洗して可溶性ナトリウム
塩をＮａ換算で１０００ｐｐｍ以下とする工程とを経由
させることにより、可溶性硫酸塩含有量と可溶性ナトリ
ウム塩含有量の少ない高純度黄色含水酸化鉄粒子とした
後、該高純度黄色含水酸化鉄粒子を含む水分散液のｐＨ
値を１０以上又は４以下に調整し、次いで、アルミニウ
ム化合物を添加、攪拌した後、該分散液のｐＨ値を５〜
９の範囲に再調整することにより、前記高純度黄色含水
酸化鉄粒子の粒子表面にアルミニウムの水酸化物を被着
させることからなる耐熱性黄色含水酸化鉄顔料の製造法
である。That is, the present invention provides yellow iron oxide hydroxide particles
After heat treatment in an alkaline aqueous solution having a pH value of 10 or more, it is filtered and washed with water to obtain a soluble sulfate of 200 in terms of SO 4.
Soluble sulfate content is obtained by passing through a step of adjusting to 0 ppm or less and a step of performing heat treatment in an acidic aqueous solution having a pH value of 4 or less, filtering and washing with water to adjust the soluble sodium salt to 1000 ppm or less in terms of Na. Content of the high-purity yellow iron oxide hydroxide particles having a small amount of soluble sodium salt, and the pH of the aqueous dispersion containing the high-purity yellow iron oxide hydroxide particles.
After adjusting the value to 10 or more or 4 or less, and then adding and stirring the aluminum compound, the pH value of the dispersion liquid is 5 to 5
It is a method for producing a heat-resistant yellow iron oxide hydroxide pigment, which comprises re-adjusting to a range of 9 to deposit aluminum hydroxide on the particle surface of the high-purity yellow iron oxide hydroxide particles.
【００１８】次に、本発明実施にあたっての諸条件につ
いて述べる。Next, various conditions for implementing the present invention will be described.
【００１９】本発明における黄色含水酸化鉄粒子は、
第一鉄塩水溶液に当量以上の水酸化アルカリ水溶液を加
えて得られる水酸化第一鉄コロイドを含む懸濁液を、ｐ
Ｈ値が１１以上、８０℃以下の温度で酸素含有ガスを通
気して酸化反応を行うことにより針状黄色含水酸化鉄
（ゲータイト）粒子を生成する方法、第一鉄塩水溶液
と炭酸アルカリ水溶液とを反応させて得られるＦｅＣＯ
3 を含む懸濁液を、必要により熟成した後、酸素含有ガ
スを通気してｐＨ値が８〜１０の範囲で酸化反応を行う
ことにより紡錘状黄色含水酸化鉄（ゲータイト）粒子を
生成する方法、第一鉄塩水溶液に当量未満の水酸化ア
ルカリ水溶液又は炭酸アルカリ水溶液を添加して得られ
る水酸化第一鉄コロイドを含む第一鉄塩水溶液に酸素含
有ガスを通気して酸化反応を行うことにより、ｐＨが４
以下の溶液中から針状黄色含水酸化鉄（ゲータイト）核
粒子を生成させ、次いで、該針状黄色含水酸化鉄（ゲー
タイト）核粒子を含む第一鉄塩水溶液に、該第一鉄塩水
溶液中のＦｅ2+に対し当量以上の水酸化アルカリ水溶液
を添加した後、酸素含有ガスを通気して酸化反応を行う
ことにより、ｐＨ値が１１以上の溶液中で前記針状黄色
含水酸化鉄（ゲータイト）核粒子を成長させる方法、
第一鉄塩水溶液に当量未満の水酸化アルカリ水溶液又は
炭酸アルカリ水溶液を添加して得られる水酸化第一鉄コ
ロイドを含む第一鉄塩水溶液に酸素含有ガスを通気して
酸化反応を行うことにより、ｐＨ値が５以下の溶液中か
ら針状黄色含水酸化鉄（ゲータイト）核粒子を生成さ
せ、次いで、酸性乃至中性領域で前記針状黄色含水酸化
鉄（ゲータイト）核粒子を成長させる方法等により得る
ことができ、得られた黄色含水酸化鉄粒子は、平均長軸
径が０．１〜１．０μｍ、平均短軸径が０．０２〜０．
１０μｍ、軸比（長軸径／短軸径）が２〜２０、ＢＥＴ
比表面積が１０〜１８０ｍ2 ／ｇである。The yellow iron oxide hydroxide particles in the present invention are:
A suspension containing a ferrous hydroxide colloid obtained by adding an equivalent amount or more of an alkali hydroxide aqueous solution to the ferrous salt aqueous solution is
A method of producing needle-shaped yellow iron oxide hydroxide (goethite) particles by carrying out an oxidation reaction by passing an oxygen-containing gas at a temperature of H value of 11 or more and 80 ° C. or less, a ferrous salt aqueous solution and an alkali carbonate aqueous solution. FeCO obtained by reacting
A method of producing spindle-shaped yellow iron oxide hydroxide (goethite) particles by aging a suspension containing 3 as necessary, and then aerating an oxygen-containing gas to carry out an oxidation reaction in a pH value range of 8 to 10. The oxygen-containing gas is passed through the ferrous salt aqueous solution containing the ferrous hydroxide colloid obtained by adding less than the equivalent amount of the aqueous alkaline hydroxide solution or the aqueous alkali carbonate solution to the oxidation reaction to carry out the oxidation reaction. The pH is 4
Needle-shaped yellow iron oxide hydroxide (goethite) core particles are produced from the following solution, and then, in a ferrous salt aqueous solution containing the needle-shaped yellow iron hydroxide oxide (goethite) core particles, the ferrous salt aqueous solution is added. After adding an equivalent amount or more of an aqueous solution of alkali hydroxide to Fe 2+ , the oxygen-containing gas is passed through to carry out an oxidation reaction, so that the needle-shaped yellow iron oxide hydroxide (goethite) in a solution having a pH value of 11 or more is obtained. ) How to grow nuclear particles,
By carrying out an oxidation reaction by passing an oxygen-containing gas through an aqueous ferrous salt solution containing a ferrous hydroxide colloid obtained by adding an aqueous solution of an alkali hydroxide or an aqueous solution of alkali carbonate in an amount less than the equivalent to the aqueous solution of ferrous salt , A method of producing needle-shaped yellow iron oxide hydroxide (goethite) core particles from a solution having a pH value of 5 or less, and then growing the needle-shaped yellow iron hydroxide oxide (goethite) core particles in an acidic or neutral region And the obtained yellow iron oxide hydroxide particles have an average major axis diameter of 0.1 to 1.0 μm and an average minor axis diameter of 0.02 to 0.
10 μm, axial ratio (major axis diameter / minor axis diameter) 2 to 20, BET
The specific surface area is 10 to 180 m 2 / g.
【００２０】尚、黄色含水酸化鉄粒子の色相を調整する
ことを目的として、黄色含水酸化鉄（ゲータイト）粒子
の生成反応中に、粒子粉末の長軸径、短軸径、軸比等の
諸特性を制御する為のＮｉ、Ｚｎ、Ｐ、Ｓｉ、Ａｌ等Ｆ
ｅ以外の異種元素を添加してもよく、この場合には、生
成黄色含水酸化鉄粒子中に、これらＦｅ以外の異種元素
が含有される。For the purpose of adjusting the hue of the yellow iron oxide hydroxide particles, various factors such as the major axis diameter, the minor axis diameter, and the axial ratio of the particle powder are generated during the reaction for producing the yellow iron oxide hydroxide particles (goethite). Ni, Zn, P, Si, Al, etc. F for controlling characteristics
Heterogeneous elements other than e may be added, and in this case, the heterogeneous elements other than Fe are contained in the produced yellow iron oxide hydroxide particles.
【００２１】本発明において使用する黄色含水酸化鉄粒
子は、上述した反応溶液中から生成した黄色含水酸化鉄
粒子を、濾別、水洗して得られる湿ケーキ、該湿ケーキ
を水中に分散させた分散スラリー、前記湿ケーキを乾燥
した乾燥粉末、乾燥した粉末を水中に再分散させた再分
散スラリーのいずれの形態であってもよいが、前記分散
スラリーを用いるのが効率上、作業上好ましい。The yellow iron oxide hydroxide particles used in the present invention are obtained by filtering the yellow iron oxide hydroxide particles produced from the above reaction solution and washing with water, and the wet cake is dispersed in water. It may be in any form of a dispersed slurry, a dry powder obtained by drying the wet cake, and a redispersed slurry obtained by redispersing the dried powder in water. However, the use of the dispersed slurry is preferable in terms of efficiency and workability.
【００２２】尚、反応溶液中の生成黄色含水酸化鉄粒子
を常法により、濾別、水洗することにより得られる黄色
含水酸化鉄粒子は、通常、鉄原料である硫酸第一鉄塩水
溶液に由来する可溶性硫酸塩をＳＯ4 換算で通常３００
０〜１００００ｐｐｍ程度、アルカリ原料である水酸化
ナトリウムに由来する可溶性ナトリウム塩をＮａ換算で
通常１５００〜１００００ｐｐｍ程度含有している。The yellow iron oxide hydroxide particles obtained by filtering and washing the formed yellow iron hydroxide oxide particles in the reaction solution by a conventional method are usually derived from an aqueous ferrous sulfate salt solution which is an iron raw material. Usually 300 a soluble sulfate in terms of SO 4 to
About 0 to 10,000 ppm, and a soluble sodium salt derived from sodium hydroxide, which is an alkali raw material, is usually contained at about 1500 to 10,000 ppm in terms of Na.
【００２３】本発明のｐＨ値が１０以上のアルカリ性水
溶液中における黄色含水酸化鉄粒子の加熱処理は、黄色
含水酸化鉄粒子の湿ケーキ、分散スラリー、乾燥粉末、
再分散スラリーと水とを混合して黄色含水酸化鉄粒子を
含む水懸濁液を調整し、該水懸濁液中にアルカリ水溶液
を添加してｐＨ値を１０以上に調整した後、加熱するこ
とによって行う。The heat treatment of the yellow iron oxide hydroxide particles in the alkaline aqueous solution having a pH value of 10 or more according to the present invention is carried out by wet cake of yellow iron oxide hydroxide particles, dispersion slurry, dry powder,
The redispersion slurry and water are mixed to prepare an aqueous suspension containing yellow iron oxide hydroxide particles, an alkaline aqueous solution is added to the aqueous suspension to adjust the pH value to 10 or more, and then the mixture is heated. By doing.
【００２４】ｐＨ値の調整のために使用するアルカリ水
溶液としては、水酸化ナトリウム、水酸化カリウム等を
使用することができる。As the alkaline aqueous solution used for adjusting the pH value, sodium hydroxide, potassium hydroxide or the like can be used.
【００２５】水懸濁液中の黄色含水酸化鉄粒子の濃度
は、可溶性硫酸塩の除去効率を考慮すれば、２〜１５重
量％程度、好ましくは３〜１０重量％程度に調整するこ
とが好ましい。The concentration of the yellow iron oxide hydroxide particles in the water suspension is adjusted to about 2 to 15% by weight, preferably about 3 to 10% by weight in consideration of the removal efficiency of soluble sulfate. .
【００２６】ｐＨ値が１０未満の場合には、黄色含水酸
化鉄粒子の粒子内部や粒子表面に吸着している可溶性硫
酸塩を十分抽出除去することが困難である。可溶性硫酸
塩の除去効率を考慮すれば、ｐＨ値が１０．５以上が好
ましい。必要以上にアルカリ水溶液を添加する意味はな
く、経済性を考慮するとその上限値はｐＨ値が１３．９
程度である。When the pH value is less than 10, it is difficult to sufficiently extract and remove the soluble sulfates adsorbed inside or on the surface of the yellow iron oxide hydroxide particles. Considering the removal efficiency of soluble sulfate, the pH value is preferably 10.5 or more. There is no point in adding an alkaline aqueous solution more than necessary, and considering economic efficiency, the upper limit is a pH value of 13.9.
It is about.
【００２７】黄色含水酸化鉄粒子を含有しているアルカ
リ性懸濁液の加熱温度は、好ましくは４０℃以上、より
好ましくは６０℃以上であり、その上限値は１００℃以
下であることが好ましい。４０℃未満である場合には、
可溶性硫酸塩を抽出除去するのに長時間かかり好ましく
ない。１００℃を越える場合には、オートクレーブ等の
特殊な装置が必要となり、得られる黄色含水酸化鉄粒子
は、耐熱性改善処理工程の前後で色相の変化が大きくな
る。The heating temperature of the alkaline suspension containing yellow iron oxide hydroxide particles is preferably 40 ° C. or higher, more preferably 60 ° C. or higher, and its upper limit is preferably 100 ° C. or lower. If the temperature is below 40 ° C,
It takes a long time to extract and remove the soluble sulfate, which is not preferable. If the temperature exceeds 100 ° C., a special device such as an autoclave is required, and the obtained yellow iron oxide hydroxide particles have a large change in hue before and after the heat resistance improving treatment step.
【００２８】黄色含水酸化鉄粒子を含有しているアルカ
リ性懸濁液の加熱処理は、黄色含水酸化鉄粒子中に含有
される可溶性硫酸塩をＳＯ4 換算で２０００ｐｐｍ以
下、好ましくは１５００ｐｐｍ以下、より好ましくは１
０００ｐｐｍ以下となるまで行えばよい。可溶性硫酸塩
をＳＯ4 換算で３０００〜１００００ｐｐｍ程度含有し
ている黄色含水酸化鉄粒子の場合は、通常、３０分間以
上、好ましくは６０分間以上加熱処理することが好まし
い。必要以上に長時間加熱処理することは意味がなく、
可溶性硫酸塩の除去効率、経済性を考慮すれば、その上
限値は３６０分間程度である。The heat treatment of the alkaline suspension containing the yellow iron oxide hydroxide particles includes the soluble sulfate contained in the yellow iron oxide hydroxide particles in an amount of not more than 2000 ppm, preferably not more than 1500 ppm, more preferably not more than 1500 ppm in terms of SO 4. Is 1
It suffices to carry out until it becomes 000 ppm or less. In the case of yellow iron oxide hydroxide particles containing a soluble sulfate salt in an amount of about 3000 to 10000 ppm in terms of SO 4 , it is usually preferable to heat-treat for 30 minutes or longer, preferably for 60 minutes or longer. It is meaningless to heat-treat for a longer time than necessary,
Considering the efficiency of removing the soluble sulfate and the economical efficiency, the upper limit is about 360 minutes.
【００２９】本発明のｐＨ値が４以下の酸性水溶液中に
おける黄色含水酸化鉄粒子の加熱処理は、黄色含水酸化
鉄粒子の湿ケーキ、分散スラリー、乾燥粉末、再分散ス
ラリーと水とを混合して黄色含水酸化鉄粒子を含む水懸
濁液を調整し、該水懸濁液中に酸性水溶液を添加してｐ
Ｈ値を４以下に調整した後、加熱することによって行
う。In the present invention, the heat treatment of the yellow iron oxide hydroxide particles in an acidic aqueous solution having a pH value of 4 or less is carried out by mixing a wet cake of yellow iron oxide hydroxide particles, a dispersion slurry, a dry powder, and a redispersion slurry with water. To prepare an aqueous suspension containing yellow iron oxide hydroxide particles, add an acidic aqueous solution to the aqueous suspension, and p
It is performed by heating after adjusting the H value to 4 or less.
【００３０】ｐＨ値を調整するために使用する酸水溶液
としては、塩酸、硝酸、酢酸、シュウ酸等を使用するこ
とができる。As the aqueous acid solution used for adjusting the pH value, hydrochloric acid, nitric acid, acetic acid, oxalic acid or the like can be used.
【００３１】水懸濁液中の黄色含水酸化鉄粒子の濃度
は、可溶性ナトリウム塩の除去効率を考慮すれば、２〜
１５重量％、好ましくは３〜１０重量％程度に調整する
ことが好ましい。The concentration of the yellow iron oxide hydroxide particles in the water suspension is from 2 to 2, considering the removal efficiency of the soluble sodium salt.
It is preferable to adjust to 15% by weight, preferably about 3 to 10% by weight.
【００３２】ｐＨ値が４を越える場合には、黄色含水酸
化鉄粒子の粒子内部や粒子表面に強く吸着している可溶
性ナトリウム塩を十分抽出除去することが困難である。
可溶性ナトリウム塩の除去効率を考慮すれば、ｐＨ値が
３．５以下が好ましい。必要以上に酸水溶液を添加する
意味はなく、経済性を考慮するとその下限値はｐＨ値が
０．１程度である。When the pH value exceeds 4, it is difficult to sufficiently extract and remove the soluble sodium salt strongly adsorbed on the inside or surface of the yellow iron oxide hydroxide particles.
Considering the removal efficiency of the soluble sodium salt, the pH value is preferably 3.5 or less. There is no point in adding an aqueous acid solution more than necessary, and the lower limit of the pH value is about 0.1 in consideration of economic efficiency.
【００３３】黄色含水酸化鉄粒子を含有している酸性懸
濁液の加熱温度は、好ましくは４０℃以上、より好まし
くは６０℃以上であり、その上限値は１００℃以下であ
ることが好ましい。４０℃未満である場合には、可溶性
ナトリウム塩を抽出除去するのに長時間かかり好ましく
ない。１００℃を越える場合には、オートクレーブ等の
特殊な装置が必要となり、得られる黄色含水酸化鉄粒子
は、耐熱性改善処理工程の前後で色相の変化が大きくな
る。The heating temperature of the acidic suspension containing yellow iron oxide hydroxide particles is preferably 40 ° C. or higher, more preferably 60 ° C. or higher, and the upper limit is preferably 100 ° C. or lower. When the temperature is lower than 40 ° C, it takes a long time to remove the soluble sodium salt by extraction, which is not preferable. If the temperature exceeds 100 ° C., a special device such as an autoclave is required, and the obtained yellow iron oxide hydroxide particles have a large change in hue before and after the heat resistance improving treatment step.
【００３４】黄色含水酸化鉄粒子を含有している酸性懸
濁液の加熱処理は、黄色含水酸化鉄粒子中に含有される
可溶性ナトリウム塩をＮａ換算で１０００ｐｐｍ以下、
好ましくは７００ｐｐｍ以下、より好ましくは５００ｐ
ｐｍ以下となるまで行えばよい。可溶性ナトリウム塩を
Ｎａ換算で１５００〜１００００ｐｐｍ程度含有してい
る黄色含水酸化鉄粒子の場合は、通常、３０分間以上、
好ましくは６０分間以上加熱処理することが好ましい。
必要以上に長時間加熱処理することは意味がなく、可溶
性ナトリウム塩の除去効率、経済性を考慮すれば、その
上限値は３６０分間程度である。The heat treatment of the acidic suspension containing the yellow iron oxide hydroxide particles includes the soluble sodium salt contained in the yellow iron oxide hydroxide particles in an amount of 1000 ppm or less in terms of Na,
It is preferably 700 ppm or less, more preferably 500 p
It may be performed until it becomes pm or less. In the case of yellow iron oxide hydroxide particles containing a soluble sodium salt in the range of 1500 to 10000 ppm in terms of Na, usually 30 minutes or more,
It is preferable to perform heat treatment for 60 minutes or more.
It is meaningless to heat-treat for a longer time than necessary, and in consideration of the removal efficiency of soluble sodium salts and economical efficiency, the upper limit value is about 360 minutes.
【００３５】本発明のｐＨ値が１０以上のアルカリ性水
溶液中における加熱処理とｐＨ値が４以下の酸性水溶液
中における加熱処理は、いずれが先でも後でもよく、先
の加熱処理終了後、濾別、水洗して得られる黄色含水酸
化鉄粒子を水中に再分散させ、次いで、後の加熱処理を
行えばよい。The heat treatment of the present invention in an alkaline aqueous solution having a pH value of 10 or more and the heat treatment in an acidic aqueous solution having a pH value of 4 or less may be either first or later. After completion of the previous heat treatment, filtration is performed. The yellow iron oxide hydroxide particles obtained by washing with water may be redispersed in water, and then the subsequent heat treatment may be performed.
【００３６】本発明のｐＨ値が１０以上のアルカリ性水
溶液中における加熱処理とｐＨ値が４以下の酸性水溶液
中における加熱処理とが終了した後、懸濁液中の黄色含
水酸化鉄粒子は、常法により濾別、水洗する。After the heat treatment of the present invention in an alkaline aqueous solution having a pH value of 10 or more and the heat treatment in an acidic aqueous solution having a pH value of 4 or less, the yellow iron oxide hydroxide particles in the suspension are Filter and wash with water.
【００３７】濾別、水洗して得られた黄色含水酸化鉄粒
子は、可溶性硫酸塩がＳＯ4 換算で２０００ｐｐｍ以
下、好ましくは１５００ｐｐｍ以下、より好ましくは１
０００ｐｐｍ以下であり、下限値は、工業性、経済性を
考慮すれば０．１ｐｐｍ程度である。可溶性ナトリウム
塩はＮａ換算で１０００ｐｐｍ以下、好ましくは７００
ｐｐｍ以下、より好ましくは５００ｐｐｍ以下であり、
下限値は、工業性、経済性を考慮すれば０．１ｐｐｍ程
度である。The yellow iron oxide hydroxide particles obtained by filtration and washing with water have a soluble sulfate of 2000 ppm or less, preferably 1500 ppm or less, more preferably 1 in terms of SO 4.
It is 000 ppm or less, and the lower limit value is about 0.1 ppm in consideration of industrial efficiency and economic efficiency. Soluble sodium salt is 1000 ppm or less in terms of Na, preferably 700
ppm or less, more preferably 500 ppm or less,
The lower limit value is about 0.1 ppm in consideration of industrial efficiency and economic efficiency.
【００３８】本発明のｐＨ値が１０以上のアルカリ性水
溶液中における加熱処理とｐＨ値が４以下の酸性水溶液
中における加熱処理とを経由させた黄色含水酸化鉄粒子
は、上述した通り、高純度の粒子であり、電子顕微鏡観
察の結果、個々の粒子がバラバラになっており、粒子相
互の凝集が解きほぐされたものである。The yellow iron oxide hydroxide particles of the present invention, which have been subjected to the heat treatment in an alkaline aqueous solution having a pH value of 10 or more and the heat treatment in an acidic aqueous solution having a pH value of 4 or less, have high purity as described above. The particles are particles, and as a result of observation with an electron microscope, the individual particles are disjointed, and the aggregation of the particles is disentangled.
【００３９】本発明においては、高純度化のための加熱
処理が終了した後、濾別、水洗して得られる湿ケーキ、
該湿ケーキを水中に分散させた分散スラリー、前記湿ケ
ーキを乾燥した乾燥粉末、該乾燥粉末を水中に再分散さ
せた再分散スラリーのいずれかと水とを混合して高純度
黄色含水酸化鉄粒子を含む水懸濁液を調整する。次い
で、該水懸濁液中のｐＨ値を１０以上又は４以下に調整
した後、アルミニウム化合物を添加、攪拌し、次いで、
水分散液のｐＨ値を５〜９の範囲に再調整することによ
り、上記アルミニウム化合物をアルミニウムの水酸化物
として前記高純度黄色含水酸化鉄粒子の粒子表面に沈
澱、被着させた後、濾別水洗、乾燥する。In the present invention, a wet cake obtained by filtering and washing with water after completion of heat treatment for high purification,
High-purity yellow iron oxide hydroxide particles obtained by mixing water with any one of a dispersion slurry in which the wet cake is dispersed in water, a dry powder obtained by drying the wet cake, and a redispersion slurry in which the dry powder is redispersed in water. A water suspension containing is prepared. Next, after adjusting the pH value in the water suspension to 10 or more or 4 or less, an aluminum compound is added and stirred, and then,
By re-adjusting the pH value of the aqueous dispersion to a range of 5 to 9, the aluminum compound as aluminum hydroxide is precipitated and deposited on the particle surface of the high-purity yellow iron oxide hydroxide particles, and then filtered. Separately wash with water and dry.
【００４０】高純度黄色含水酸化鉄粒子の粒子表面にア
ルミニウムの水酸化物で被覆するに際してのｐＨ値の調
整は、通常使用されるアルカリ水溶液、酸水溶液を使用
すればよい。For coating the particle surface of the high-purity yellow iron oxide hydroxide particles with aluminum hydroxide, the pH value may be adjusted by using a commonly used alkaline aqueous solution or acid aqueous solution.
【００４１】アルカリ水溶液としては、水酸化ナトリウ
ム水溶液、水酸化カリウム水溶液、アンモニア水溶液等
を使用することができる。As the alkaline aqueous solution, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, ammonia aqueous solution or the like can be used.
【００４２】酸水溶液としては、塩酸、硝酸、酢酸、シ
ュウ酸、硫酸等を使用することができる。As the acid aqueous solution, hydrochloric acid, nitric acid, acetic acid, oxalic acid, sulfuric acid or the like can be used.
【００４３】アルミニウム化合物を添加する前のｐＨ値
は、ｐＨ値が１０以上又は４以下であることが必要であ
る。ｐＨ値が１０未満、ｐＨ値が４を越える場合には、
添加したアルミニウム化合物が瞬時にアルミニウムの水
酸化物として沈澱してしまい、黄色含水酸化鉄粒子の粒
子表面に均一に被着することが困難となる。The pH value before adding the aluminum compound needs to be 10 or more or 4 or less. If the pH value is less than 10 or more than 4,
The added aluminum compound instantly precipitates as a hydroxide of aluminum, and it becomes difficult to uniformly deposit the yellow iron oxide hydroxide particles on the particle surface.
【００４４】本発明におけるアルミニウム化合物を添加
した懸濁液の攪拌は、ｐＨ値が１０以上又は４以下で行
う。ｐＨ値が１０未満の場合、ｐＨ値が４を越える場合
には、イオン状のアルミニウム塩が黄色含水酸化鉄粒子
を含む懸濁液中に均一に混合されにくく、黄色含水酸化
鉄粒子の粒子表面にアルミニウムの水酸化物が均一に沈
澱、被着することが困難となる。The stirring of the suspension containing the aluminum compound in the present invention is carried out at a pH value of 10 or more or 4 or less. If the pH value is less than 10 or more than 4, the ionic aluminum salt is difficult to be uniformly mixed in the suspension containing the yellow iron oxide hydroxide particles, and the particle surface of the yellow iron oxide hydroxide particles is It is difficult to evenly precipitate and deposit aluminum hydroxide.
【００４５】黄色含水酸化鉄粒子の粒子表面にアルミニ
ウムの水酸化物を沈澱、被着する時の懸濁液温度は、常
温でもよいが、均一に被着する為には、好ましくは４０
℃以上、より好ましくは６０℃以上である。The suspension temperature at which the aluminum hydroxide is precipitated and deposited on the surface of the yellow iron oxide hydroxide particles may be room temperature, but is preferably 40 for uniform deposition.
℃ or more, more preferably 60 ℃ or more.
【００４６】本発明における黄色含水酸化鉄粒子の粒子
表面にアルミニウムの水酸化物を沈着させる際の懸濁液
のｐＨ値は、５〜９の範囲となるように調整する。ｐＨ
値が５未満の場合、９を越える場合は、黄色含水酸化鉄
粒子の粒子表面にアルミニウムの水酸化物を沈澱、被着
することができない。The pH value of the suspension when aluminum hydroxide is deposited on the surface of the yellow iron oxide hydroxide particles in the present invention is adjusted to be in the range of 5-9. pH
When the value is less than 5 or more than 9, the aluminum hydroxide cannot be precipitated and deposited on the surface of the yellow iron oxide hydroxide particles.
【００４７】本発明におけるアルミニウム化合物の添加
量は、黄色含水酸化鉄粒子に対しＡｌ換算で０．１〜２
０．０重量％である。０．１重量％未満の場合には、黄
色含水酸化鉄粒子の粒子表面にアルミニウムの水酸化物
を十分、沈澱、被着することが困難となり、本発明の目
的とする耐熱性の改善効果、分散性の改善効果が得られ
難い。２０．０重量％を越える場合には、黄色含水酸化
鉄粒子の耐熱性の改善効果、分散性の改善効果は得られ
るが、効果がほぼ飽和し、必要以上に添加する意味がな
い。黄色含水酸化鉄粒子の耐熱性の改善効果、分散性の
改善効果を考慮すれば、好ましくは０．１５〜５．０重
量％である。The addition amount of the aluminum compound in the present invention is 0.1 to 2 in terms of Al with respect to the yellow iron oxide hydroxide particles.
0.0% by weight. When the amount is less than 0.1% by weight, it becomes difficult to sufficiently deposit and deposit aluminum hydroxide on the surface of the yellow iron oxide hydroxide particles, and the heat resistance improving effect aimed at by the present invention, It is difficult to obtain the effect of improving dispersibility. When it exceeds 20.0% by weight, the effect of improving the heat resistance and the effect of improving the dispersibility of the yellow iron oxide hydroxide particles can be obtained, but the effect is almost saturated and it is meaningless to add more than necessary. Considering the heat resistance improving effect and the dispersibility improving effect of the yellow iron oxide hydroxide particles, the content is preferably 0.15 to 5.0% by weight.
【００４８】本発明においては、添加したアルミニウム
の化合物は、ほぼ全量がアルミニウムの水酸化物となっ
て、黄色含水酸化鉄粒子の粒子表面に沈澱、被着され
る。In the present invention, almost all of the added aluminum compound becomes aluminum hydroxide, which is precipitated and deposited on the surface of the yellow iron oxide hydroxide particles.
【００４９】本発明の方法により得られる黄色含水酸化
鉄粒子は、分散性が優れており、殊に、光沢が８０〜１
５０％、好ましくは８５〜１５０％であり、しかも、耐
熱性が向上した、殊に、耐熱温度が２４０℃以上、好ま
しくは２５０℃以上であるとともに、耐熱性改善処理工
程の前後における色相の変化が小さい、殊に、ΔＬが絶
対値で１．０以下、好ましくは０．５以下であって、Δ
ａが絶対値で１．０以下、好ましくは０．５以下であっ
て、Δｂが絶対値で１．０以下、好ましくは０．５以下
である。The yellow iron oxide hydroxide particles obtained by the method of the present invention have excellent dispersibility, and in particular, have a gloss of 80 to 1
50%, preferably 85-150%, with improved heat resistance, in particular, a heat resistant temperature of 240 ° C. or higher, preferably 250 ° C. or higher, and a change in hue before and after the heat resistance improving treatment step. Is small, in particular, ΔL is 1.0 or less in absolute value, preferably 0.5 or less,
The absolute value of a is 1.0 or less, preferably 0.5 or less, and the absolute value of Δb is 1.0 or less, preferably 0.5 or less.
【００５０】[0050]
【作用】本発明において最も重要な点は、黄色含水酸化
鉄粒子を、ｐＨ値が１０以上のアルカリ性水溶液中で加
熱処理した後、濾別、水洗して可溶性硫酸塩をＳＯ4 換
算で２０００ｐｐｍ以下とする工程とｐＨ値が４以下の
酸性水溶液中で加熱処理した後、濾別、水洗して可溶性
ナトリウム塩をＮａ換算で１０００ｐｐｍ以下とする工
程とを経由させることにより、可溶性硫酸塩含有量と可
溶性ナトリウム塩含有量の少ない高純度黄色含水酸化鉄
粒子とした後、該高純度黄色含水酸化鉄粒子を含む水分
散液のｐＨ値を１０以上又は４以下に調整し、次いで、
アルミニウム化合物を添加、攪拌した後、該分散液のｐ
Ｈ値を５〜９の範囲に再調整することにより、前記高純
度黄色含水酸化鉄粒子の粒子表面にアルミニウムの水酸
化物を被着させた場合には、分散性が優れており、しか
も、耐熱性が向上しているとともに、耐熱性改善処理工
程の前後における色相の変化が小さいものであるという
事実である。The most important point in the present invention is that the yellow iron oxide hydroxide particles are heat-treated in an alkaline aqueous solution having a pH value of 10 or more, then filtered and washed to obtain soluble sulfate of 2000 ppm or less in terms of SO 4. And a step of heat treating in an acidic aqueous solution having a pH value of 4 or less, followed by filtration and washing with water to reduce the soluble sodium salt to 1000 ppm or less in terms of Na. After producing high-purity yellow iron oxide hydroxide particles having a low content of soluble sodium salt, the pH value of the aqueous dispersion containing the high-purity yellow iron oxide hydroxide particles is adjusted to 10 or more or 4 or less, and then,
After adding and stirring an aluminum compound, p of the dispersion liquid
When the H value is readjusted in the range of 5 to 9 and the hydroxide of aluminum is adhered to the particle surface of the high-purity yellow iron oxide hydroxide particles, the dispersibility is excellent, and further, The fact is that the heat resistance is improved and the change in hue before and after the heat resistance improvement treatment step is small.
【００５１】黄色含水酸化鉄粒子の耐熱性が向上した理
由について、本発明者は、アルミニウムの水酸化物で黄
色含水酸化鉄粒子の粒子表面を被着するに先立って、あ
らかじめ高純度黄色含水酸化鉄粒子としておくことによ
り、黄色含水酸化鉄粒子の二次凝集が十分解きほぐされ
て凝集粒子を１個１個バラバラにすることができ、その
結果、粒子１個１個の粒子表面にアルミニウムの水酸化
物を十分且つ均一に被着することができたことによるも
のと考えている。With respect to the reason why the heat resistance of the yellow iron oxide hydroxide particles is improved, the present inventor has previously prepared a high-purity yellow oxide hydroxide powder before depositing the surface of the yellow iron oxide hydroxide particles with aluminum hydroxide. By using iron particles, the secondary agglomeration of the yellow iron oxide hydroxide particles can be sufficiently unraveled and the agglomerated particles can be dissociated one by one. It is believed that this is because the hydroxide could be applied sufficiently and uniformly.
【００５２】高純度黄色含水酸化鉄粒子は、二次凝集が
十分解きほぐされたものであるという事実について以下
に説明する。The fact that the high-purity yellow iron oxide hydroxide particles are those in which the secondary agglomeration is sufficiently disentangled will be explained below.
【００５３】反応溶液中から生成した黄色含水酸化鉄
（ゲータイト）粒子は、前述した通り、鉄原料が硫酸第
一鉄である場合には当然反応母液中に可溶性硫酸塩〔Ｓ
Ｏ4 --〕が多量に存在するのである。As mentioned above, the yellow iron oxide hydroxide (goethite) particles produced from the reaction solution are naturally soluble in the reaction mother liquor [S] when the iron raw material is ferrous sulfate.
O 4 -] is the abundant.
【００５４】特に、酸性溶液中から黄色含水酸化鉄（ゲ
ータイト）粒子を生成する場合には、同時に、Ｎａ2 Ｓ
Ｏ4 等可溶性硫酸塩を生じる一方、Ｋ+ 、ＮＨ4 + 、Ｎ
ａ+、等のアルカリ金属を含有しているので、アルカリ
金属や硫酸塩を含む沈澱を生じ易く、この沈澱は、ＲＦ
ｅ3 （ＳＯ4 ）（ＯＨ）6 （Ｒ＝Ｋ+ 、ＮＨ4 + 、Ｎａ
+ ）で示される。これら沈澱物は難溶性の含硫酸塩で常
法による水洗によっては除去することができない。In particular, when yellow iron oxide hydroxide (goethite) particles are produced from an acidic solution, at the same time, Na 2 S
While producing soluble sulfates such as O 4 , K + , NH 4 + , N
Since it contains an alkali metal such as a + , a precipitate containing an alkali metal or a sulfate is liable to be formed.
e 3 (SO 4 ) (OH) 6 (R = K + , NH 4 + , Na
+ ). These precipitates are hardly soluble sulfates and cannot be removed by washing with water in a conventional manner.
【００５５】硫酸第一鉄と水酸化ナトリウムとを用いて
ｐＨ値が１１以上のアルカリ性水溶液中から黄色含水酸
化鉄（ゲータイト）粒子を生成する場合には、同時に生
成される硫酸塩はＮａ2 ＳＯ4 であり、又、母液中にＮ
ａＯＨが存在し、これらは共に可溶性であるため黄色含
水酸化鉄（ゲータイト）粒子を十分水洗すれば本質的に
はＮａ2 ＳＯ4 およびＮａＯＨを除去できるはずであ
る。When ferrous sulfate and sodium hydroxide are used to produce yellow iron oxide hydroxide (goethite) particles from an alkaline aqueous solution having a pH value of 11 or more, the sulfate produced at the same time is Na 2 SO 4. 4 and N in the mother liquor
Since aOH is present and these are both soluble, it should be possible to essentially remove Na 2 SO 4 and NaOH by sufficiently washing the yellow iron oxide hydroxide (goethite) particles with water.
【００５６】しかし、一般には黄色含水酸化鉄（ゲータ
イト）粒子の結晶性が小さい為、水洗効率が悪く、常法
により水洗した場合、なお、粒子中に可溶性硫酸塩〔Ｓ
Ｏ4 --〕、可溶性ナトリウム塩〔Ｎａ+ 〕を多く含んで
いる。However, since the yellow iron oxide hydroxide (goethite) particles generally have a low crystallinity, the washing efficiency is poor, and when washed by a conventional method, the soluble sulfate salt [S
O 4 -], contains a large amount of soluble sodium salt [Na +].
【００５７】上述した可溶性硫酸塩や可溶性ナトリウム
塩は、黄色含水酸化鉄粒子の粒子内部に含有されたり、
粒子表面に存在することにより、黄色含水酸化鉄（ゲー
タイト）粒子相互を架橋しながら強固に結合し、黄色含
水酸化鉄粒子相互間の凝集は一層強まることになる。上
記黄色含水酸化鉄粒子凝集物をｐＨ値が１０以上のアル
カリ性水溶液中で加熱処理すると、アルカリ性水溶液が
黄色含水酸化鉄（ゲータイト）粒子凝集物の表面から内
部まで十分浸透し、その結果、粒子内部や粒子表面及び
凝集物内部に強く結合している硫酸塩の結合力が徐々に
弱まり、粒子内部や粒子表面及び凝集物内部から硫酸塩
が解離され、同時に、可溶性ナトリウム塩も水洗除去し
やすくなるものと考えられる。The above-mentioned soluble sulfate or soluble sodium salt is contained in the inside of the yellow iron oxide hydroxide particles,
By being present on the particle surface, the yellow iron oxide hydroxide (goethite) particles are strongly bonded to each other while being cross-linked, and the aggregation of the yellow iron oxide hydroxide particles is further strengthened. When the yellow iron oxide hydroxide particles aggregate is heat-treated in an alkaline aqueous solution having a pH value of 10 or more, the alkaline aqueous solution sufficiently penetrates from the surface to the inside of the yellow iron oxide hydroxide (goethite) particles aggregate, and as a result, the inside of the particles is The binding force of the sulfates strongly bound to the surface of the particles and the inside of the agglomerates gradually weakens, and the sulfates are dissociated from the inside of the particles and the surface of the particles and the inside of the agglomerates. It is considered to be a thing.
【００５８】一方、黄色含水酸化鉄（ゲータイト）粒子
凝集物をｐＨ値が４以下の酸性水溶液中で加熱処理する
と、酸性水溶液が黄色含水酸化鉄（ゲータイト）粒子凝
集物の表面から内部まで十分浸透し、その結果、粒子内
部や粒子表面及び凝集物内部に強く結合しているナトリ
ウム塩の結合力が徐々に弱まり、粒子内部や粒子表面及
び凝集物内部からナトリウム塩が解離され、同時に、可
溶性硫酸塩も水洗除去しやすくなるものと考えられる。On the other hand, when the yellow iron oxide hydroxide (goethite) particle aggregates are heat-treated in an acidic aqueous solution having a pH value of 4 or less, the acidic aqueous solution sufficiently penetrates from the surface to the inside of the yellow iron hydroxide oxide (goethite) particle aggregates. As a result, the binding force of the sodium salt strongly bonded to the inside of the particle, the surface of the particle, and the inside of the aggregate is gradually weakened, and the sodium salt is dissociated from the inside of the particle, the surface of the particle, and the inside of the aggregate. It is considered that salt can be easily removed by washing with water.
【００５９】[0059]
【発明の実施の形態】本発明の代表的な実施の形態は、
次の通りである。DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment of the present invention is as follows.
It is as follows.
【００６０】尚、粒子の平均長軸径、平均短軸径は、い
ずれも電子顕微鏡写真に示される粒子３５０個の長軸
径、短軸径をそれぞれ測定し、その平均値で示した。The average major axis diameter and the average minor axis diameter of the particles are the average values obtained by measuring the major axis diameter and the minor axis diameter of 350 particles shown in the electron micrographs.
【００６１】黄色含水酸化鉄中の可溶性硫酸塩及び可溶
性ナトリウム塩は、黄色含水酸化鉄粉末５ｇ及び純水１
００ｍｌを秤量して２００ｍｌビーカーに添加して５分
間煮沸をした後、室温まで冷却し、次いで、蒸発により
損失した量の純水を追加した後、濾別して得られる濾液
を用いて、濾液中のＳＯ4 量及びＮａ量を誘導結合プラ
ズマ発光分光分析装置ＳＰＳ４０００（セイコー電子工
業（株）製）により測定した値で示した。The soluble sulfate and soluble sodium salt in the yellow iron oxide hydroxide were 5 g of yellow iron oxide powder and 1 part of pure water.
00 ml was weighed and added to a 200 ml beaker and boiled for 5 minutes, then cooled to room temperature, and then the amount of pure water lost by evaporation was added, and then the filtrate obtained by filtration was used. The amount of SO 4 and the amount of Na are shown by the values measured by the inductively coupled plasma emission spectroscopic analyzer SPS4000 (manufactured by Seiko Denshi Kogyo KK).
【００６２】黄色含水酸化鉄粒子の粒子表面に被着して
いるＡｌ量は、蛍光Ｘ線分析により測定した。The amount of Al deposited on the surface of the yellow iron oxide hydroxide particles was measured by fluorescent X-ray analysis.
【００６３】黄色含水酸化鉄顔料の耐熱性は、熱分析装
置ＳＳＣ５０００（セイコー電子工業（株）製）を用い
て被測定物の示差走査熱量測定（ＤＳＣ）を行い、得ら
れた該ＤＳＣチャート上に示されるピークを形成する２
つの変曲点のうち最初の変曲点を構成する２つの曲線の
それぞれについて接線を引き、両接線の交点に対応する
温度を読み取って、その温度で示した。The heat resistance of the yellow iron oxide hydroxide pigment was measured by differential scanning calorimetry (DSC) using a thermal analyzer SSC5000 (manufactured by Seiko Denshi Kogyo Co., Ltd.). Forming the peak shown in 2
A tangent line was drawn for each of the two curves forming the first inflection point of the two inflection points, and the temperature corresponding to the intersection of both tangents was read and indicated by that temperature.
【００６４】黄色含水酸化鉄顔料の色相（Ｌ* 値、ａ*
値及びｂ* 値）及び光沢（分散性）は、下記の方法によ
り、黄色含水酸化鉄顔料を用いた溶剤系塗料を作成し、
その塗料を冷間圧延鋼板（０．８ｍｍ×７０ｍｍ×１５
０ｍｍ）（ＪＩＳ Ｇ−３１４１）に１５０μｍの厚み
で塗布、乾燥して塗膜を形成することにより得られた測
定用試料片を用いて測定した。Hue of yellow iron oxide hydroxide pigment (L * value, a *
Value and b * value) and gloss (dispersibility), a solvent-based paint using a yellow iron oxide hydroxide pigment is prepared by the following method,
Apply the paint to a cold rolled steel plate (0.8 mm x 70 mm x 15
0 mm) (JIS G-3141) was applied to a thickness of 150 μm and dried to form a coating film. The measurement sample piece was used for measurement.
【００６５】溶剤系塗料は、下記のようにして製造し
た。The solvent-based paint was manufactured as follows.
【００６６】黄色含水酸化鉄顔料１０ｇと下記割合のア
ミノアルキッド樹脂及びシンナーとを、３ｍｍφガラス
ビーズ９０ｇとともに１４０ｍｌのガラスびんに入れペ
イントシェーカーで９０分間混合、分散し、ミルベース
を作製した。10 g of the yellow iron oxide hydroxide pigment and the aminoalkyd resin and thinner in the following proportions were placed in a 140 ml glass bottle together with 90 g of 3 mmφ glass beads, and mixed and dispersed for 90 minutes with a paint shaker to prepare a mill base.
【００６７】 黄色含水酸化鉄顔料 １２．２重量部 アミノアルキッド樹脂 アミラックＮｏ．１０２６ １９．５重量部 （商品名：関西ペイント（株）製） シンナー ７．３重量部Yellow iron oxide hydroxide pigment 12.2 parts by weight Amino alkyd resin Amylak No. 1026 19.5 parts by weight (Product name: Kansai Paint Co., Ltd.) Thinner 7.3 parts by weight
【００６８】次に、上記ミルベースに下記割合のアミノ
アルキッド樹脂を配合して、更にペインシェーカーで１
５分間混合、分散し、溶剤系塗料を得た。Next, the above-mentioned mill base was blended with the following ratio of aminoalkyd resin, and further blended with a pain shaker.
The mixture was mixed and dispersed for 5 minutes to obtain a solvent-based paint.
【００６９】 ミルベース ３９．０重量部 アミノアルキッド樹脂 アミラックＮｏ．１０２６ ６１．０重量部 （商品名：関西ペイント（株）製）Millbase 39.0 parts by weight Amino alkyd resin Amylak No. 1026 61.0 parts by weight (Product name: Kansai Paint Co., Ltd.)
【００７０】色相を表すＬ* 値（明度）、ａ* 値（赤色
度）及びｂ* 値（黄色度）は、上記測定用試料片を用い
てＨｕｎｔｅｒのＬａｂ空間によりＬ* 値、ａ* 値及び
ｂ*値をそれぞれ測色し、国際照明委員会（Ｃｏｍｍｉ
ｓｓｉｏｎ Ｉｎｔｅｒｎａｔｉｏｎｎａｌｅ ｄｅ
ｌ’Ｅｃｌａｉｒａｇｅ、ＣＩＥ）１９７６（Ｌ* 、ａ
* 、ｂ* ）均等知覚空間に従って表示した値で示した。
尚、測色用には、多光源分光測色計（ＭＳＣ−ＩＳ−２
Ｄ、スガ試験機（株）製）Ｍｏｌｔｉ−ｓｐｃｔｒｏ−
ｃｏｌｏｕｒ−Ｍｅｔｅｒを用いた。[0070] L * value representing a hue (brightness), a * value (redness) and b * values (yellowness) is, L * value by the Lab space of Hunter by using the measurement sample piece, a * value And b * values are measured respectively, and the International Commission on Illumination (Commi
session International de
l'Eclairage, CIE) 1976 (L * , a
* , B * ) The values are shown according to the uniform perceptual space.
A multi-light source spectrophotometer (MSC-IS-2) is used for color measurement.
D, manufactured by Suga Test Instruments Co., Ltd., Molti-spctro-
color-Meter was used.
【００７１】黄色含水酸化鉄顔料の色相の変化は、耐熱
性改善処理工程の前後における黄色含水酸化鉄粒子のＬ
* 値、ａ* 値及びｂ* 値のそれぞれを測定し、耐熱性改
善処理の前後における黄色含水酸化鉄粒子のＬ* 値、ａ
* 値及びｂ* 値のそれぞれの差をΔＬ* 、Δａ* 及びΔ
ｂ* として示した。ΔＬ* 、Δａ* 及びΔｂ* の絶対値
が小さい程、色相の変化が小さいことを意味する。The change in hue of the yellow iron oxide hydroxide oxide is caused by the L of yellow iron oxide hydroxide particles before and after the heat resistance improving treatment step.
Each of the * value, a * value, and b * value was measured, and the L * value, a, of the yellow iron oxide hydroxide particles before and after the heat resistance improvement treatment were measured.
* Each of the difference and b * values [Delta] L *, .DELTA.a * and Δ
Shown as b * . The smaller the absolute value of ΔL * , Δa * and Δb * , the smaller the change in hue.
【００７２】光沢度は、上記測定用試料片の塗膜をデジ
タル光沢計ＵＧＶ−５Ｄ（スガ試験機（株）製）を用い
て入射角２０°で測定した時の光沢度（グロス）の値で
示した。光沢度（グロス）の値が高い程、分散性が優れ
ていることを示す。The glossiness is a value of glossiness (gloss) when the coating film of the measurement sample piece is measured with a digital glossmeter UGV-5D (manufactured by Suga Test Instruments Co., Ltd.) at an incident angle of 20 °. Indicated by. The higher the gloss value, the better the dispersibility.
【００７３】前記の方法により酸性水溶液中から得ら
れた針状黄色含水酸化鉄（ゲータイト）粒子（反応溶液
の一部を抜き取り、水洗して得られた黄色含水酸化鉄粒
子の特性は、平均長軸径０．３９μｍ、平均短軸径０．
０６３μｍ、軸比（長軸径／短軸径）６．２、ＢＥＴ比
表面積値１９．８ｍ2 ／ｇ、可溶性硫酸塩はＳＯ4 換算
で５５６０ｐｐｍ、可溶性ナトリウム塩はＮａ換算で２
２８０ｐｐｍであった。）の湿ケーキ３．３ｋｇ（乾燥
粉末に換算して１ｋｇ）を水１９ｌに攪拌機を用いて解
膠し、次いで、高速ディゾルバーおよび縦型ビーズミル
を用いて、懸濁液中の黄色含水酸化鉄粒子をよく分散さ
せた。この時の水懸濁液中の黄色含水酸化鉄濃度は４．
５重量％であって、ｐＨ値は５．７であった。Needle-shaped yellow iron oxide hydroxide (goethite) particles obtained from the acidic aqueous solution by the above-mentioned method (the characteristics of the yellow iron oxide hydroxide particles obtained by extracting a part of the reaction solution and washing with water are Shaft diameter 0.39 μm, average minor axis diameter 0.
063 μm, axial ratio (major axis diameter / minor axis diameter) 6.2, BET specific surface area value of 19.8 m 2 / g, soluble sulfate of 5560 ppm in terms of SO 4 , soluble sodium salt of 2 in terms of Na
It was 280 ppm. ) Wet cake 3.3 kg (1 kg in terms of dry powder) was deflocculated in 19 l of water using a stirrer, and then using a high speed dissolver and a vertical bead mill, yellow iron oxide hydroxide particles in suspension. Well dispersed. At this time, the concentration of yellow iron oxide hydroxide in the water suspension was 4.
It was 5% by weight and the pH value was 5.7.
【００７４】上記水懸濁液を攪拌しながら加熱昇温し８
０℃とした。水懸濁液の攪拌を続けながら０．１Ｎの水
酸化ナトリウム水溶液を水懸濁液のｐＨ値が１１．０と
なるまで添加し３０分間維持した。The temperature of the water suspension is raised by heating with stirring.
It was set to 0 ° C. While continuing the stirring of the aqueous suspension, a 0.1N aqueous sodium hydroxide solution was added until the pH value of the aqueous suspension reached 11.0 and maintained for 30 minutes.
【００７５】プレスフィルターを用いて濾別し、通水し
ながら十分水洗した。得られた黄色含水酸化鉄粒子は、
可溶性硫酸塩がＳＯ4 換算で２８０ｐｐｍ、可溶性ナト
リウム塩はＮａ換算で１０７４ｐｐｍであった。It was filtered using a press filter and washed thoroughly with water. The obtained yellow iron oxide hydroxide particles,
The soluble sulfate was 280 ppm in terms of SO 4 , and the soluble sodium salt was 1074 ppm in terms of Na.
【００７６】上記湿ケーキ（含水固形物）を再度水１９
ｌ中に解膠して得られた水懸濁液（黄色含水酸化鉄濃度
は４．５重量％）を８０℃まで加熱昇温した後、１Ｎの
酢酸水溶液を水懸濁液のｐＨ値が３．９となるまで添加
し、さらに３０分間維持した。The above wet cake (hydrous solid matter) was re-watered.
The temperature of the aqueous suspension obtained by deflocculating in 1 (yellow iron oxide hydroxide concentration is 4.5% by weight) was raised to 80 ° C. Add until 3.9 and hold for another 30 minutes.
【００７７】プレスフィルターを用いて濾別し、通水し
ながら十分水洗した。得られた黄色含水酸化鉄粒子は、
可溶性硫酸塩がＳＯ4 換算で２５６ｐｐｍ、可溶性ナト
リウム塩はＮａ換算で７９ｐｐｍであった。It was filtered using a press filter and washed thoroughly with water. The obtained yellow iron oxide hydroxide particles,
The soluble sulfate was 256 ppm in terms of SO 4 , and the soluble sodium salt was 79 ppm in terms of Na.
【００７８】得られた湿ケーキを攪拌機を用いて、水１
９ｌに解膠して得られたｐＨ値が５．１の懸濁液（黄色
含水酸化鉄濃度は４．５重量％）を８０℃まで加熱昇温
した。次に、０．１ＮのＮａＯＨをｐＨ値が１０．３に
なるまで添加し、攪拌を続けながらアルミン酸ナトリウ
ム（ＮＡ−１７０、住友化学工業（株）製）１２０ｇを
加え１０分間保持した。その後５Ｎの酢酸水溶液をｐＨ
値が６．０になるまで添加した後３０分間維持し、黄色
含水酸化鉄粒子の粒子表面にアルミニウムの水酸化物を
沈澱、被着させた。The wet cake thus obtained was mixed with water 1 using a stirrer.
A suspension having a pH value of 5.1 (a yellow iron oxide hydroxide concentration of 4.5% by weight) obtained by deflocculating to 9 l was heated to 80 ° C and heated. Next, 0.1 N NaOH was added until the pH value reached 10.3, and 120 g of sodium aluminate (NA-170, manufactured by Sumitomo Chemical Co., Ltd.) was added while continuing stirring and held for 10 minutes. After that, add 5N acetic acid aqueous solution to pH.
After adding until the value reached 6.0, it was maintained for 30 minutes, and aluminum hydroxide was precipitated and deposited on the surface of the yellow iron oxide hydroxide particles.
【００７９】続いて、プレスフィルターを用いて濾別
し、通水しながら十分水洗して湿ケーキを得る。湿ケー
キを１２０℃で２４時間乾燥させた後、自由粉砕機Ｍ−
２型（商品名：（株）奈良機械製作所製）で解砕し、黄
色酸化鉄粒子粉末を得た。Then, the mixture is filtered using a press filter and washed thoroughly with water to obtain a wet cake. After drying the wet cake at 120 ° C. for 24 hours, the free crusher M-
It was crushed with a type 2 (trade name: manufactured by Nara Machinery Co., Ltd.) to obtain yellow iron oxide particle powder.
【００８０】得られた黄色含水酸化鉄（ゲータイト）粒
子は、粒子表面がＡｌ換算で１．２７ｗｔ％のアルミニ
ウムの水酸化物で被覆されており、平均長軸径が０．３
８μｍ、平均短軸径が０．０６３μｍ、ＢＥＴ比表面積
値が２１．７ｍ2 ／ｇであって、可溶性硫酸塩がＳＯ4
換算で２３４ｐｐｍ、可溶性ナトリウム塩はＮａ換算で
８３ｐｐｍであった。また、耐熱温度は２７０℃、色相
の変化はΔＬ* ＝−０．１、Δａ* ＝−０．２及びΔｂ
* ＝＋０．３であり、光沢度は８８％であった。The surface of the obtained yellow iron oxide hydroxide (goethite) particles was coated with 1.27 wt% of aluminum hydroxide in terms of Al, and the average major axis diameter was 0.3.
8 μm, average minor axis diameter of 0.063 μm, BET specific surface area value of 21.7 m 2 / g, and soluble sulfate of SO 4
It was 234 ppm in terms of conversion and the soluble sodium salt was 83 ppm in terms of Na. Further, the heat resistant temperature is 270 ° C., and the change in hue is ΔL * = − 0.1, Δa * = − 0.2 and Δb.
* = + 0.3 and the glossiness was 88%.
【００８１】[0081]
【実施例】次に、実施例並びに比較例を挙げる。EXAMPLES Next, examples and comparative examples will be given.
【００８２】＜黄色含水酸化鉄粒子粉末の種類＞被処理
粒子である黄色含水酸化鉄粒子粉末として表１に示され
る被処理粒子１乃至被処理粒子３を準備した。<Type of Yellow Iron Oxide Hydroxide Particle Powder> Particles 1 to 3 to be treated shown in Table 1 were prepared as yellow iron oxide hydroxide particle powder to be treated.
【００８３】[0083]
【表１】 [Table 1]
【００８４】実施例１〜５ 被処理粒子の種類、水懸濁液中の含水酸化鉄濃度、アル
カリ水溶液中の処理工程におけるｐＨ値、加熱温度及び
加熱時間、酸性水溶液中の処理工程におけるｐＨ値、加
熱温度及び加熱時間を種々変化させた以外は、前記発明
の実施の形態と同様にして高純度化処理を行った。Examples 1 to 5 Types of particles to be treated, iron oxide hydroxide concentration in water suspension, pH value in treatment step in alkaline aqueous solution, heating temperature and heating time, pH value in treatment step in acidic aqueous solution A high-purification treatment was performed in the same manner as in the embodiment of the present invention except that the heating temperature and the heating time were variously changed.
【００８５】この時の主要製造条件及び諸特性を表２に
示す。Table 2 shows the main manufacturing conditions and various characteristics at this time.
【００８６】[0086]
【表２】 [Table 2]
【００８７】実施例６〜１０ アルミニウムの水酸化物による被着工程における水懸濁
液中の高純度含水酸化鉄濃度、添加するアルミニウム化
合物の種類、量、添加前のｐＨ値、懸濁液の最終ｐＨ値
を種々変化させた以外は、前記発明の実施の形態と同様
にして粒子表面にアルミニウムの水酸化物が被着されて
いる高純度黄色含水酸化鉄粒子粉末を得た。Examples 6 to 10 High-purity iron oxide hydroxide concentration in water suspension in the step of coating with aluminum hydroxide, type and amount of aluminum compound to be added, pH value before addition, and suspension High-purity yellow iron oxide hydroxide particles powder having aluminum hydroxide deposited on the particle surfaces were obtained in the same manner as in the above-described embodiment of the invention, except that the final pH value was variously changed.
【００８８】この時の主要製造条件を表３に、粒子表面
にアルミニウムの水酸化物が被着されている高純度黄色
含水酸化鉄粒子粉末の諸特性を４に示す。Table 3 shows the main production conditions at this time, and Table 4 shows various characteristics of the high-purity yellow iron oxide hydroxide particles having aluminum hydroxide deposited on the surface of the particles.
【００８９】[0089]
【表３】 [Table 3]
【００９０】[0090]
【表４】 [Table 4]
【００９１】比較例１ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用い、いずれの処理も施さ
ないで、その諸特性を測定した結果を表４に示す。表４
に示す通り、反応溶液中から濾別、水洗、乾燥して得ら
れる黄色含水酸化鉄は、耐熱性が悪いものであった。Comparative Example 1 Using the same yellow iron oxide hydroxide particles as the yellow iron oxide hydroxide particles to be treated described in the embodiment of the invention, without performing any treatment, various properties were measured and the results are shown in Table 4. Shown in. Table 4
As shown in, the yellow iron oxide hydroxide obtained by filtering, washing with water and drying from the reaction solution had poor heat resistance.
【００９２】比較例２ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用い、アルカリ性水溶液中
における加熱処理及び酸性水溶液中における加熱処理を
施すことなく、水懸濁液中の黄色含水酸化鉄濃度を４．
５重量％、アルミン酸ナトリウムの添加量をＡｌ換算で
２．６８重量％、添加前の懸濁液ｐＨ値を１０．０、懸
濁液の最終ｐＨ値を７．０に調整した以外は発明の実施
の形態と同様にして、アルミニウムの水酸化物が被着さ
れている黄色含水酸化鉄粒子を得た。Comparative Example 2 Using the same yellow iron oxide hydroxide particles as the yellow iron oxide hydroxide particles to be treated described in the embodiment of the invention, without performing heat treatment in an alkaline aqueous solution and heat treatment in an acidic aqueous solution, 3. Adjust the concentration of yellow iron oxide hydroxide in the water suspension.
Invention except that 5 wt%, the amount of sodium aluminate added was 2.68 wt% in terms of Al, the suspension pH value before addition was 10.0, and the final pH value of the suspension was 7.0 In the same manner as in the above embodiment, yellow hydrous iron oxide particles coated with aluminum hydroxide were obtained.
【００９３】得られた粒子表面にアルミニウムの水酸化
物が被着されている黄色含水酸化鉄粒子の諸特性を表４
に示す。表４に示す通り、反応溶液中から濾別、水洗、
乾燥して得られる黄色含水酸化鉄粒子の粒子表面にアル
ミニウムの水酸化物を被着させるものは、耐熱性が未だ
不十分なものであった。Table 4 shows the characteristics of the yellow iron oxide hydroxide particles in which the surface of the obtained particles is coated with aluminum hydroxide.
Shown in As shown in Table 4, the reaction solution was filtered, washed with water,
The yellow iron oxide hydroxide particles obtained by drying were coated with aluminum hydroxide on the particle surface, but the heat resistance was still insufficient.
【００９４】比較例３ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用い、酸性水溶液中におけ
る加熱処理を施すことなく、水懸濁液中の黄色含水酸化
鉄濃度を４．５重量％、ｐＨ値を１１．０、加熱温度６
０℃、加熱時間３０分間に調整した以外は、発明の実施
の形態と同様にしてアルカリ性水溶液中で処理を行うと
ともに、水懸濁液中の黄色含水酸化鉄濃度を４．５重量
％、アルミン酸ナトリウムの添加量を０．５５重量％、
添加前の懸濁液ｐＨ値を１０．０、懸濁液の最終ｐＨ値
を６．０に調整した以外は発明の実施の形態と同様にし
て、アルミニウムの水酸化物が被着されている黄色含水
酸化鉄粒子を得た。Comparative Example 3 Using the same yellow iron oxide hydroxide particles as the yellow iron oxide hydroxide particles to be treated described in the embodiment of the invention, the yellow iron hydroxide particles in the aqueous suspension were subjected to no heat treatment in an acidic aqueous solution. Iron oxide hydroxide concentration is 4.5% by weight, pH value is 11.0, heating temperature is 6
The treatment is carried out in an alkaline aqueous solution in the same manner as in the embodiment of the invention except that the temperature is 0 ° C. and the heating time is 30 minutes, and the concentration of yellow iron oxide hydroxide in the water suspension is 4.5% by weight. 0.55% by weight of sodium acidate,
Aluminum hydroxide is deposited in the same manner as in the embodiment of the invention except that the suspension pH value before addition is adjusted to 10.0 and the final suspension pH value is adjusted to 6.0. Yellow iron oxide hydroxide particles were obtained.
【００９５】得られた粒子表面にアルミニウムの水酸化
物が被着されている黄色含水酸化鉄粒子の諸特性を表４
に示す。表４に示す通り、黄色含水酸化鉄は、耐熱性が
未だ不十分なものであった。Table 4 shows the characteristics of the yellow iron oxide hydroxide particles in which the surface of the obtained particles is coated with aluminum hydroxide.
Shown in As shown in Table 4, the yellow iron oxide hydroxide had insufficient heat resistance.
【００９６】尚、上記アルカリ性水溶液中における加熱
処理を施した直後に抜き取った黄色含水酸化鉄粒子の可
溶性硫酸塩はＳＯ4 換算で６９６ｐｐｍ、可溶性ナトリ
ウム塩はＮａ換算で２０３３ｐｐｍであった。The soluble sulfate of the yellow iron oxide hydroxide particles extracted immediately after the heat treatment in the alkaline aqueous solution was 696 ppm in terms of SO 4 , and the soluble sodium salt was 2033 ppm in terms of Na.
【００９７】比較例４ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用い、アルカリ性水溶液中
における加熱処理を施すことなく、水懸濁液中の含水酸
化鉄濃度４．５重量％、ｐＨ値を３．８、加熱温度６０
℃、加熱時間３０分間に調整した以外は、発明の実施の
形態と同様にして酸性水溶液中で加熱処理を行い、黄色
含水酸化鉄粒子を得た。Comparative Example 4 Using the same yellow iron oxide hydroxide particles as the yellow iron oxide hydroxide particles to be treated described in the embodiment of the present invention, water-containing water in an aqueous suspension was prepared without heat treatment in an alkaline aqueous solution. Iron oxide concentration 4.5% by weight, pH value 3.8, heating temperature 60
Heat treatment was carried out in an acidic aqueous solution in the same manner as in the embodiment of the invention except that the temperature was adjusted to 30 ° C. and the heating time was 30 minutes to obtain yellow iron oxide hydroxide particles.
【００９８】得られた黄色含水酸化鉄粒子の諸特性を表
４に示す。表４に示す通り、黄色含水酸化鉄は、耐熱性
が未だ不十分なものであった。Table 4 shows various properties of the obtained yellow iron oxide hydroxide particles. As shown in Table 4, the yellow iron oxide hydroxide had insufficient heat resistance.
【００９９】尚、上記酸性水溶液中における加熱処理を
施した直後の黄色含水酸化鉄粒子は、可溶性硫酸塩がＳ
Ｏ4 換算で２８８８ｐｐｍ、可溶性ナトリウム塩はＮａ
換算で４６５ｐｐｍであった。Immediately after the heat treatment in the above-mentioned acidic aqueous solution, the yellow iron oxide hydroxide particles contain soluble sulfate as S
2888ppm in terms of O 4 , soluble sodium salt is Na
It was 465 ppm in terms of conversion.
【０１００】比較例５ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用いた水懸濁液濃度が４．
５重量％の黄色含水酸化鉄スラリー２１．４ｌ（固形分
として１ｋｇに相当する。）に１３ＮのＮａＯＨ溶液を
加えてｐＨ値を１３．０とした。スラリー７００ｍｌを
分取し、内容積１ｌのオートクレーブ（東洋高圧（株）
製）に入れ、撹拌しながら昇温し、２２０℃で３０分保
持した後、冷却した。スラリーを取り出し水を用いたデ
カンテーションによって濾液が中性になるまで水で十分
水洗した。次いで、ヌッチェを用いて濾別した湿ケーキ
を１２０℃で２４時間乾燥した後、粉砕し、黄色酸化鉄
粒子粉末を得た。Comparative Example 5 Using the same yellow iron oxide hydroxide particles as the yellow iron oxide hydroxide particles to be treated described in the embodiment of the invention, the concentration of the aqueous suspension was 4.
A pH value of 13.0 was obtained by adding 13N NaOH solution to 21.4 l of a 5 wt% yellow iron oxide hydroxide slurry (corresponding to 1 kg as a solid content). 700 ml of the slurry was sampled and an autoclave with an internal volume of 1 l (Toyo High Pressure Co., Ltd.)
Manufactured), the temperature was raised with stirring, the temperature was maintained at 220 ° C. for 30 minutes, and then cooled. The slurry was taken out and thoroughly washed with water until the filtrate became neutral by decantation with water. Next, the wet cake filtered using a Nutsche was dried at 120 ° C. for 24 hours and then pulverized to obtain yellow iron oxide particle powder.
【０１０１】得られた黄色含水酸化鉄粒子粉末の諸特性
を表４に示す。表４に示す通り、耐熱性改善処理工程の
前後での色相の変化が大きいものであった。Table 4 shows various properties of the obtained yellow iron oxide hydroxide particles. As shown in Table 4, there was a large change in hue before and after the heat resistance improvement treatment step.
【０１０２】比較例６ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用いた水懸濁液濃度が４．
５重量％の黄色含水酸化鉄スラリー２１．４ｌ（固形分
として１ｋｇに相当する。）に硫酸アルミニウム１５
６．４ｇを含む水溶液２ｌを投入し、よく撹拌した。ス
ラリー７００ｍｌを分取し、内容積１ｌのオートクレー
ブ（東洋高圧（株）製）に入れ、撹拌しながら昇温し、
２２０℃で３０分保持した後、冷却した。スラリーを取
り出しヌッチェを用いて濾別し、濾液が中性になるまで
水洗した。得られた湿ケーキを１２０℃で２４時間乾燥
した後、粉砕し、黄色酸化鉄粒子粉末を得た。Comparative Example 6 Using the same yellow iron oxide hydroxide particles as the yellow iron oxide hydroxide particles to be treated as described in the embodiment of the invention, the aqueous suspension concentration was 4.
21.4 l of a 5 wt% yellow iron oxide hydroxide slurry (corresponding to 1 kg as a solid content) was added with 15 parts of aluminum sulfate.
2 l of an aqueous solution containing 6.4 g was added and well stirred. 700 ml of the slurry was sampled and put into an autoclave (manufactured by Toyo High Pressure Co., Ltd.) having an internal volume of 1 l, and heated while stirring.
After holding at 220 ° C. for 30 minutes, it was cooled. The slurry was taken out, filtered using a Nutsche, and washed with water until the filtrate became neutral. The obtained wet cake was dried at 120 ° C. for 24 hours and then pulverized to obtain yellow iron oxide particle powder.
【０１０３】得られた黄色含水酸化鉄粒子粉末の諸特性
を表４に示す。表４に示す通り、耐熱性改善処理工程の
前後での色相の変化が大きいものであった。Table 4 shows various properties of the obtained yellow iron oxide hydroxide particles. As shown in Table 4, there was a large change in hue before and after the heat resistance improvement treatment step.
【０１０４】比較例７ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用いた水懸濁液濃度が４．
５重量％の黄色含水酸化鉄スラリーに６ＮのＮａＯＨ溶
液を加えてｐＨ値を１３．０とした。スラリー７００ｍ
ｌ（固形分として３２．７ｇに相当する。）を分取し、
内容積１ｌのオートクレーブ（東洋高圧（株）製）に入
れ、撹拌しながら昇温し、１８０℃で１２０分保持した
後、冷却した。取り出したスラリーに撹拌しながらアル
ミン酸ナトリウム（ＮＡ−１７０：住友化学工業（株）
製）溶液４．３２ｇを加え、徐々に希硫酸を加えてｐＨ
値を６．０に調整した。水を用いたデカンテーションに
よって十分に水洗した後、ヌッチェを用いて濾別した。
得られた湿ケーキを１２０℃で２４時間乾燥した後、粉
砕し、黄色酸化鉄粒子粉末を得た。Comparative Example 7 The concentration of the aqueous suspension was the same as that of the yellow iron oxide hydroxide particles to be treated as described in the embodiment of the present invention.
A pH value of 13.0 was obtained by adding 6N NaOH solution to a 5 wt% yellow iron oxide hydroxide slurry. Slurry 700m
1 (corresponding to 32.7 g of solid content) was collected,
The mixture was placed in an autoclave (manufactured by Toyo High Pressure Co., Ltd.) having an internal volume of 1 liter, heated with stirring, kept at 180 ° C. for 120 minutes, and then cooled. Sodium aluminate (NA-170: Sumitomo Chemical Co., Ltd.) while stirring the taken-out slurry.
(Manufactured by Mitsui Chemicals Co., Ltd.) 4.32 g of the solution, and dilute sulfuric acid is gradually added to adjust the pH.
The value was adjusted to 6.0. After thoroughly washing with water by decantation with water, it was filtered using a Nutsche.
The obtained wet cake was dried at 120 ° C. for 24 hours and then pulverized to obtain yellow iron oxide particle powder.
【０１０５】得られた黄色含水酸化鉄粒子粉末の諸特性
を表４に示す。表４に示す通り、耐熱性改善処理工程の
前後での色相の変化が大きいものであった。Table 4 shows various properties of the obtained yellow iron oxide hydroxide particles. As shown in Table 4, there was a large change in hue before and after the heat resistance improvement treatment step.
【０１０６】比較例８ 発明の実施の形態に記載の被処理黄色含水酸化鉄粒子と
同一の黄色含水酸化鉄粒子を用いた水懸濁液濃度が４．
５重量％の黄色含水酸化鉄スラリー２１．４ｌ（固形分
として１ｋｇに相当する。）に６ＮのＮａＯＨ溶液を加
えてｐＨ値を１２．０とした。スラリー７００ｍｌ（固
形分として３２．７ｇに相当する。）を分取し、これに
アルミン酸ナトリウム（ＮＡ−１７０：住友化学工業
（株）製）溶液２．８７ｇを加え、内容積１ｌのオート
クレーブ（東洋高圧（株）製）に入れ、撹拌しながら昇
温し、１８０℃で６０分間水熱処理した後冷却した。取
り出したスラリーを水を用いたデカンテーションによっ
て十分に水洗した後、ヌッチェを用いて濾別した。得ら
れた湿ケーキを１２０℃で４時間乾燥した後、粉砕し、
黄色酸化鉄粒子粉末を得た。Comparative Example 8 Using the same yellow iron oxide hydroxide particles as the yellow iron oxide hydroxide particles to be treated according to the embodiment of the invention, the concentration of the aqueous suspension was 4.
A pH value of 12.0 was obtained by adding 6N NaOH solution to 21.4 l of 5 wt% yellow iron oxide hydroxide slurry (corresponding to 1 kg as solid content). 700 ml of slurry (corresponding to 32.7 g as a solid content) was collected, to which 2.87 g of sodium aluminate (NA-170: manufactured by Sumitomo Chemical Co., Ltd.) solution was added, and an autoclave with an internal volume of 1 liter ( It was placed in Toyo High Pressure Co., Ltd., heated while stirring, hydrothermally treated at 180 ° C. for 60 minutes, and then cooled. The taken-out slurry was thoroughly washed with water by decantation using water, and then filtered using a Nutsche. The obtained wet cake was dried at 120 ° C. for 4 hours and then crushed,
A yellow iron oxide particle powder was obtained.
【０１０７】得られた黄色含水酸化鉄粒子粉末の諸特性
を表４に示す。表４に示す通り、耐熱性改善処理工程の
前後での色相の変化が大きいものであった。Table 4 shows various properties of the obtained yellow iron oxide hydroxide particles. As shown in Table 4, there was a large change in hue before and after the heat resistance improvement treatment step.
【０１０８】[0108]
【発明の効果】本発明に係る黄色含水酸化鉄粒子粉末の
製造法によれば、前出実施例に示した通り、分散性が優
れており、しかも、耐熱性が向上しているとともに、耐
熱性改善処理工程の前後における色相の変化が小さい黄
色含水酸化鉄粒子粉末を得ることができるので、黄色着
色顔料、殊に、道路アスファルト用や路面表示塗料用黄
色着色顔料として好ましいものである。EFFECTS OF THE INVENTION According to the method for producing the yellow iron oxide hydroxide particles according to the present invention, as shown in the above-mentioned Examples, the dispersibility is excellent, and the heat resistance is improved and the heat resistance is improved. It is preferable as a yellow coloring pigment, particularly as a yellow coloring pigment for road asphalt and road surface paints, because it is possible to obtain a powder of yellow iron oxide hydroxide particles having a small change in hue before and after the property improving treatment step.
【０１０９】また、本発明に係る黄色含水酸化鉄粒子粉
末の製造法によれば、前出実施例に示した通り、オート
クレーブ等の特殊な装置を用いることなく、常圧下で耐
熱性の改良された黄色含水酸化鉄粒子粉末を得ることが
できるので、工業的、経済的に優れたものである。Further, according to the method for producing yellow iron oxide hydroxide particles according to the present invention, heat resistance is improved under normal pressure without using a special device such as an autoclave as shown in the above-mentioned Examples. Since it is possible to obtain yellow iron oxide hydroxide particles, it is industrially and economically excellent.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 角田 博 広島県広島市中区舟入南４丁目１番２号戸 田工業株式会社創造センター内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Tsunoda 4-1-2, Funariminami, Naka-ku, Hiroshima-shi, Hiroshima The inside of Toda Kogyo Co., Ltd.
Claims (1)
上のアルカリ性水溶液中で加熱処理した後、濾別、水洗
して可溶性硫酸塩をＳＯ4 換算で２０００ｐｐｍ以下と
する工程とｐＨ値が４以下の酸性水溶液中で加熱処理し
た後、濾別、水洗して可溶性ナトリウム塩をＮａ換算で
１０００ｐｐｍ以下とする工程とを経由させることによ
り、可溶性硫酸塩含有量と可溶性ナトリウム塩含有量の
少ない高純度黄色含水酸化鉄粒子とした後、該高純度黄
色含水酸化鉄粒子を含む水分散液のｐＨ値を１０以上又
は４以下に調整し、次いで、アルミニウム化合物を添
加、攪拌した後、該分散液のｐＨ値を５〜９の範囲に再
調整することにより、前記高純度黄色含水酸化鉄粒子の
粒子表面にアルミニウムの水酸化物を被着させることを
特徴とする耐熱性黄色含水酸化鉄顔料の製造法。1. A step of heat treating yellow iron oxide hydroxide particles in an alkaline aqueous solution having a pH value of 10 or more, followed by filtration and washing with water to reduce the soluble sulfate to 2000 ppm or less in terms of SO 4 and the pH value. After the heat treatment in an acidic aqueous solution of 4 or less, the solution is filtered and washed with water to reduce the soluble sodium salt to 1000 ppm or less in terms of Na, thereby reducing the soluble sulfate content and the soluble sodium salt content. After the high-purity yellow iron oxide hydroxide particles were prepared, the pH value of the aqueous dispersion containing the high-purity yellow iron hydroxide particles was adjusted to 10 or more or 4 or less, and then an aluminum compound was added and stirred, and then the dispersion was performed. By adjusting the pH value of the liquid again in the range of 5 to 9, a hydroxide of aluminum is adhered to the particle surface of the high-purity yellow iron oxide hydroxide particles. Process for the preparation of iron hydroxide pigments.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34804795A JP3214542B2 (en) | 1995-12-14 | 1995-12-14 | Method for producing heat-resistant yellow iron-containing hydrous pigment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34804795A JP3214542B2 (en) | 1995-12-14 | 1995-12-14 | Method for producing heat-resistant yellow iron-containing hydrous pigment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09165531A true JPH09165531A (en) | 1997-06-24 |
| JP3214542B2 JP3214542B2 (en) | 2001-10-02 |
Family
ID=18394388
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34804795A Expired - Lifetime JP3214542B2 (en) | 1995-12-14 | 1995-12-14 | Method for producing heat-resistant yellow iron-containing hydrous pigment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3214542B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0887387A3 (en) * | 1997-06-23 | 1999-09-29 | Toda Kogyo Corp. | Yellow iron oxide hydroxide particles and process for producing the same |
| JP2014028947A (en) * | 2012-06-28 | 2014-02-13 | Toda Kogyo Corp | Thermal resistant yellow water-containing iron oxide pigment and manufacturing method thereof, coating material and resin composition using thermal resistant yellow water-containing iron oxide pigment |
-
1995
- 1995-12-14 JP JP34804795A patent/JP3214542B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0887387A3 (en) * | 1997-06-23 | 1999-09-29 | Toda Kogyo Corp. | Yellow iron oxide hydroxide particles and process for producing the same |
| US6027559A (en) * | 1997-06-23 | 2000-02-22 | Toda Kogyo Corporation | Yellow iron oxide hydroxide particles and process for producing the same |
| JP2014028947A (en) * | 2012-06-28 | 2014-02-13 | Toda Kogyo Corp | Thermal resistant yellow water-containing iron oxide pigment and manufacturing method thereof, coating material and resin composition using thermal resistant yellow water-containing iron oxide pigment |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3214542B2 (en) | 2001-10-02 |
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