JP3552015B2 - Nonmagnetic black pigment powder, nonmagnetic black paint using the nonmagnetic black pigment powder, and black rubber / resin composition using the nonmagnetic black pigment powder - Google Patents

Description

【０１４３】
【表２】

【０１４４】
実施例７〜１２
Ｍｎを含有している鉄を主成分とするヘマタイト構造を有する黒色粉末の種類、湿式粉砕の有無、アルカリ水溶液中加熱処理におけるｐＨ値、温度、時間を種々変化させた以外は、前記本発明の実施の形態と同様にしてアルカリ水溶液処理済黒色顔料粉末を得た。
【０１４５】
この時の主要製造条件及び諸特性を表３に示す。
【０１４６】
【表３】

【０１４７】
実施例１３〜１８
実施例７〜１２の各黒色顔料粉末を用い、表面被覆物の種類及び量を種々変化させた以外は、前記本発明の実施の形態と同様にして粒子表面が被覆物で被覆されている黒色粒子からなる黒色顔料粉末を得た。
【０１４８】
この時の主要製造条件及び諸特性を表４に示す。
【０１４９】
【表４】

【０１５０】
比較例１〜１０
アルカリ処理前のＭｎを含有している鉄を主成分とするヘマタイト構造を有する黒色顔料粉末である比較例１〜３、公知の黒色顔料粉末である比較例４〜７及びアルカリ処理後のＭｎを含有している鉄を主成分とするヘマタイト構造を有する黒色顔料粉末である比較例８〜１０を準備した。
【０１５１】
これら黒色顔料粉末の諸特性を表５及び表６に示す。
【０１５２】
尚、比較例７のＭｎ固溶酸化鉄系顔料粉末は前出特開平８−１４３３１６号公報に記載の製造法に従って製造したものである。
【０１５３】
【表５】

【０１５４】
【表６】

【０１５５】
＜塗料の製造＞
実施例１９〜３０及び比較例１１〜２０
黒色顔料粉末の種類を種々変化させた以外は、前記本発明の実施の形態と同様にして塗料を製造し、塗膜を形成した。
【０１５６】
この時の主要製造条件及び塗膜特性を表７及び表８に示す。
【０１５７】
【表７】

【０１５８】
【表８】

【０１５９】
＜樹脂組成物の製造＞
実施例３１〜４２及び比較例２１〜３０
黒色顔料粉末の種類を種々変化させた以外は、前記本発明の実施の形態と同様にして樹脂組成物を得た。
【０１６０】
この時の主要製造条件及び諸特性を表９及び表１０に示す。
【０１６１】
【表９】

【０１６２】
【表１０】

【０１６３】
【発明の効果】
本発明に係る非磁性黒色顔料粉末は、黒色度及び耐熱性が優れており、且つ、より分散性に優れているので、塗料用、ゴム・樹脂組成物用の着色材及び充填材として好適である。
【０１６４】
本発明に係る塗料は、上記諸特性を有する非磁性黒色顔料粉末を用いたことに起因して、黒色度が優れており、且つ、耐酸性に優れた塗膜を得ることができる。
【０１６５】
本発明に係るゴム・樹脂組成物は、上記諸特性を有する非磁性黒色顔料粉末を用いたことに起因して、黒色度が優れており、且つ、耐老化性に優れたゴム・樹脂組成物を得ることができる。
【図面の簡単な説明】
【図１】本発明の実施の形態で得られたアルカリ処理前のＭｎを含有している鉄を主成分とするヘマタイト構造を有する黒色顔料粉末の粒子構造を示す電子顕微鏡写真（×２００００）である。
【図２】本発明の実施の形態で得られたアルカリ処理前のＭｎを含有している鉄を主成分とするヘマタイト構造を有するアルカリ水溶液加熱処理後の黒色顔料粉末の粒子構造を示す電子顕微鏡写真（×２００００）である。[0001]
[Industrial applications]
The present invention provides a non-magnetic black pigment powder which is excellent in blackness and heat resistance, and which is more excellent in dispersibility, and when colored with the non-magnetic black pigment powder, a black coating excellent in acid resistance. An object of the present invention is to provide a black rubber / resin composition excellent in film and aging resistance.
[0002]
[Prior art]
As typical black pigments, magnetite particle powder, carbon black, fluorinated graphite and the like are known. These black pigments are widely used as paints by mixing and dispersing in vehicles, and as colorants for rubber and resins by kneading and dispersing in rubber and resins.
[0003]
In recent years, it is safe and harmless from the viewpoint of safety and health as well as the improvement of work efficiency and various characteristics in the energy saving era, and it has excellent blackness and heat resistance, as well as more excellent dispersibility. Accordingly, there is a strong demand for a black pigment powder having excellent workability and various properties.
[0004]
Conventionally used black pigments such as magnetite particle powder, carbon black, and fluorinated graphite are used when coated as L^*Value is 10-25, a^*Values of -2.5 to 2.5 and b^*The value indicates a value of -2.5 to 2.5, and is excellent in blackness.
[0005]
Next, regarding the heat resistance of the pigment, in the molding process of rubber and resin, the pigment is exposed to a high temperature, so that it is required to have excellent heat resistance.
[0006]
Further, in baking coating in which a coating film is dried at a high temperature, a pigment that does not discolor even at a high temperature of 100 to 400 ° C., which varies depending on the coating resin, is required.
[0007]
In order to improve the workability, it is important that the pigment is a nonmagnetic powder having an appropriate size and thus having an excellent dispersibility and being easy to handle.
[0008]
The good dispersibility of the pigment means that the color tone is sharp and the basic characteristics of the pigment, such as tinting strength and hiding power, are improved, as well as the gloss and sharpness of the coating film. Since the properties of the coating film such as the acid resistance and aging resistance of the film are improved, improvement in the dispersibility of the pigment is strongly required.
[0009]
Furthermore, in recent years, the natural environment such as the problem of acid rain and the living environment have been deteriorating, and in particular, improvements in the acid resistance and aging resistance of coating film-forming products and rubber and resin compositions used outdoors have been increasingly required. ing.
[0010]
Conventionally, hematite particle powders containing Mn as a safe, harmless and non-magnetic black pigment have been known (JP-B-43-17288, JP-B-47-30085, JP-B-54). JP-A-37004, JP-A-49-124127, JP-A-51-149200, JP-A-8-143316 and the like.
[0011]
[Problems to be solved by the invention]
Nonmagnetic black pigments, which have excellent blackness and heat resistance, and are more excellent in dispersibility, are currently the most demanded, but black pigments having such properties are still being obtained. Absent.
[0012]
That is, although the known magnetite particle powder is safe and harmless, it starts to change into maghemite at a temperature of 150 ° C. or higher, so that the color changes from black to brown and there is a problem in heat resistance. In addition, since the particles have magnetism, reaggregation occurs between the particles, making dispersion difficult, and workability is poor. When the coating film was formed using the magnetite particle powder, the acid resistance of the coating film was hardly good.
[0013]
The above-mentioned known carbon black is hard to say that the heat resistance is sufficient, is ultrafine particles of about 0.01 to 0.1 μm, and is a bulky powder, which is difficult to handle and has poor workability. . Also, safety and hygiene problems such as carcinogenicity have been pointed out.
[0014]
The above-mentioned known fluorinated graphite is hard to say that it is safe, and since the hue changes greatly at about 500 ° C., it is not enough to have sufficient heat resistance and dispersibility.
[0015]
The above-mentioned known hematite particle powder containing Mn is safe and harmless, but has a hue of reddish brown or blackish brown and insufficient blackness. In addition, the dispersibility is hardly sufficient. When a coating film or a rubber / resin composition was formed using the particle powder, acid resistance and aging resistance were hardly good.
[0016]
Therefore, the present invention can provide a nonmagnetic black pigment which is safe, harmless, has excellent blackness and heat resistance, and is more excellent in dispersibility. It is an object of the present invention to obtain a non-magnetic black paint having excellent properties and a black rubber / resin composition having excellent aging resistance.
[0017]
[Means for solving the problem]
The technical problem can be achieved by the present invention as described below.
[0018]
That is, the present invention has an average diameter of 0.1 to 10 μm having a hematite structure mainly containing iron containing Mn.mThe Mn content of the nonmagnetic black granular particles is 5 to 70% by weight based on the nonmagnetic black pigment powder, the powder pH value is 5.5 or more, and the content of the soluble sodium salt is Na. 500 ppm or less in conversion, and the content of soluble sulfate is SO_FourA non-magnetic black pigment powder characterized by being a non-magnetic black powder of 200 ppm or less in terms of conversion, and, if necessary, a particle surface of which is formed of aluminum hydroxide, aluminum oxide, silicon hydroxide, and silicon hydroxide. A non-magnetic black pigment powder, which is a non-magnetic black powder comprising the non-magnetic black granular particles coated with at least one oxide.
[0019]
Further, the present invention is a non-magnetic black paint, wherein any one of the above-mentioned non-magnetic black pigment powders is blended in a paint constituting base material.
[0020]
Further, the present invention is a non-magnetic black rubber / resin composition, wherein any one of the above-mentioned non-magnetic black pigment powders is blended in a rubber / resin composition constituent base material.
[0021]
The configuration of the present invention will be described in more detail as follows.
[0022]
First, the nonmagnetic black pigment powder according to the present invention will be described.
[0023]
As shown in Examples below, the nonmagnetic black powder according to the present invention was found to be nonmagnetic because of the hematite structure as a result of X-ray diffraction.
[0024]
The non-magnetic black powder according to the present invention is composed of granular particles. The average particle diameter of the non-magnetic black powder is from 0.1 to 10 μm. If it exceeds 10 μm, the particle diameter is too large, so that it is difficult to obtain a smooth surface when forming a coating film or a resin composition.
[0025]
The geometric standard deviation (σg) of the particle diameter of the nonmagnetic black powder according to the present invention is 2.0 or less, preferably 1.7 or less, more preferably 1.5 or less. When σg exceeds 2.0, the abundance ratio of the coarse particles becomes large, so that it becomes difficult to obtain the smoothness of the surface when forming a coating film or a resin composition. In consideration of industrial properties such as productivity, the lower limit of σg is 1.01.
[0026]
The nonmagnetic black powder according to the present invention has a Mn content of 5 to 40% by weight based on the nonmagnetic black pigment powder. If it is less than 5% by weight, it is difficult to obtain the required blackness. If it exceeds 40% by weight, the desired blackness can be obtained, but the blackness is saturated and there is no point in containing more than necessary. Preferably it is 9 to 35% by weight, more preferably 10 to 20% by weight.
[0027]
The non-magnetic black powder according to the present invention has a powder pH of 5.5 or more. If the powder pH value is less than 5.5, many acidic impurities remain between the particles, so that crosslinking occurs and dispersibility is hindered. In consideration of dispersibility, the powder pH value is preferably 6.5 or more, and more preferably 8.0 or more. The upper limit is a powder pH value of 12 or less, preferably a powder pH value of 11 or less, and more preferably a powder pH value of 10 or less.
[0028]
The content of the soluble sodium salt in the nonmagnetic black powder according to the present invention is 500 ppm or less in terms of Na. If it exceeds 500 ppm, impurities including sodium salt are crosslinked between particles, and dispersibility is hindered. In consideration of the dispersibility of the black pigment powder in the vehicle, the content is preferably 450 ppm or less, more preferably 400 ppm or less, and still more preferably 300 ppm or less. In consideration of industrial properties such as productivity, the lower limit is about 0.01 ppm.
[0029]
The non-magnetic black powder according to the present invention has a soluble sulfate content of SO.₄It is 200 ppm or less in conversion. If it exceeds 200 ppm, impurities including sulfates are crosslinked between particles, and dispersibility is impaired. Considering the dispersibility of the black pigment powder in the vehicle, it is preferably 170 ppm or less, more preferably 150 ppm or less. In consideration of industrial properties such as productivity, the lower limit is about 0.01 ppm.
[0030]
The non-magnetic black powder according to the present invention contains L^*The value is from 10 to 25,^*A value between -2.5 and 2.5, b^*Since the value is -2.5 to 2.5, it is comparable to a known black pigment. Considering hue, L^*The value is preferably from 10 to 24, more preferably from 15 to 23. a^*The value is preferably -2.5 to 2.0, more preferably -2.0 to 1.0. b^*The value is preferably from -2.5 to 2.0, and more preferably from -2.5 to 1.0.
[0031]
The heat resistance of the nonmagnetic black powder according to the present invention is 0 to 2.5. If it exceeds 2.5, discoloration and the like become remarkable when resin coloring or the like is performed using a black pigment powder, which is not preferable.
[0032]
The non-magnetic black paint according to the present invention, when formed into a coating film, has an L^*A value between 15 and 25,^*A value between -2.5 and 2.5, b^*Since the value is -2.5 to 2.5, it is comparable to the case where a known black pigment powder is used. Further, the glossiness is 80% or more, the acid resistance is ΔG value of 8.0 or less, and ΔL is^*The value is 1.0 or less. Considering hue, L^*The value is preferably 17 to 24, more preferably 20 to 23. a^*The value is preferably -2.5 to 2.0, more preferably -2.0 to 1.0. b^*The value is preferably -2.5 to 2.0, more preferably -2.0 to 1.0. The gloss is preferably 83% or more, more preferably 85% or more. The acid resistance is preferably such that the ΔG value is 7.0 or less, more preferably 6.0 or less. ΔL^*The value is preferably 0.8 or less, more preferably 0.6 or less.
[0033]
The non-magnetic black rubber / resin composition according to the present invention has L^*A value between 15 and 25,^*A value between -2.5 and 2.5, b^*Since the value is -2.5 to 2.5, it is comparable to the case where a known black pigment powder is used. The result of visual observation of dispersibility was in the range of 4 to 5. The aging resistance is such that the proportion of discolored portions when heated at 190 ° C. for 90 minutes is 15% or less. Considering hue, L^*The value is preferably 17 to 24, more preferably 20 to 24. a^*The value is preferably -2.5 to 2.0, more preferably -2.0 to 1.0. b^*The value is preferably -2.5 to 2.0, more preferably -2.0 to 1.0. The aging resistance is preferably 10% or less, more preferably 5% or less.
[0034]
Next, a method for producing the nonmagnetic black powder according to the present invention will be described.
[0035]
The black pigment powder according to the present invention has an average particle size of 0.05 having a hematite structure containing iron as a main component and containing Mn obtained by the following production method described in the above-mentioned JP-A-4-144924. After wet-pulverizing a slurry containing octahedral particles or spherical particles of up to 5.0 μm, the pH value of the slurry is adjusted to 13 or more, and then heated at a temperature of 80 ° C. or more, filtered, and washed with water. Can be obtained by drying.
[0036]
Octahedral particles having a hematite structure containing iron as a main component and containing Mn and having an average particle size of 0.05 to 5.0 μm are composed of a ferrous salt aqueous solution and Fe in the ferrous salt aqueous solution.²⁺The suspension containing the ferrous hydroxide colloid obtained by reacting 1.01 to 1.3 equivalents of an aqueous alkali hydroxide solution with respect to the oxygen-containing suspension is heated to a temperature range of 45 to 100 ° C. The ferrous hydroxide colloid is oxidized by a magnetite generation reaction in which gas is passed to generate magnetite particles to form a suspension containing magnetite particles, and the suspension containing the magnetite particles contains Mn or Mn and Fe.²⁺Is added in the form of an aqueous solution to make Mn of 8 to 150 atomic% based on the total Fe in the liquid, and then the suspension is heated and oxidized under the same conditions as in the above-mentioned magnetite formation reaction, thereby producing magnetite. The particle surface is coated with a hydroxide of Mn or a hydroxide of Mn and Fe, and then the magnetite particles coated with the hydroxide of Mn or the hydroxide of Mn and Fe are filtered, washed, and dried. Then, it is obtained by heating and firing in a temperature range of 750 to 1000 ° C.
[0037]
Spherical particles having an average particle size of 0.1 to 10 μm and having a hematite structure containing iron as a main component containing Mn are a ferrous salt aqueous solution and Fe in the ferrous salt aqueous solution.²⁺The suspension containing ferrous hydroxide colloid obtained by reacting 0.80 to 0.99 equivalents of an aqueous alkali hydroxide solution with respect to the oxygen-containing suspension is heated to a temperature range of 45 to 100 ° C. A suspension containing magnetite particles is generated by oxidizing the ferrous hydroxide colloid by a reaction to generate magnetite particles through which gas is passed to generate magnetite particles, and the suspension containing the magnetite particles is added to the suspension containing the magnetite particles. An aqueous solution of 8 to 150 atomic% of Mn compound with respect to Fe, the Mn compound and residual Fe²⁺After adding an aqueous solution of an alkali hydroxide in excess of 1.00 equivalent to the above, the surface of the magnetite particles was heated and oxidized under the same conditions as in the above-mentioned magnetite generation reaction, thereby making the surface of the magnetite particles Mn hydroxide or Mn and Fe. The magnetite particles coated with a hydroxide and then coated with the hydroxide of Mn or the hydroxide of Mn and Fe are separated by filtration, washed with water, dried, and then heated in a temperature range of 750 to 1000 ° C. Obtained by firing.
[0038]
Various conditions for producing octahedral particles and spherical particles having a hematite structure containing iron as a main component and containing Mn described above will be described.
[0039]
As the ferrous salt aqueous solution, ferrous sulfate, ferrous chloride and the like can be used.
[0040]
As the aqueous solution of the Mn compound, manganese sulfate, manganese chloride, or the like can be used. In order to uniformly coat the surface of the magnetite particles, it is preferable to add the aqueous solution.
[0041]
As the aqueous alkali hydroxide solution, sodium hydroxide, potassium hydroxide, or the like can be used.
[0042]
As a production method for producing octahedral magnetite particles from which the non-magnetic black pigment powder of the octahedral particles is obtained, for example, it is possible to use the technical means disclosed in Japanese Patent Publication No. 44-668. it can.
[0043]
The amount of the aqueous alkali hydroxide solution is determined by adjusting the amount of Fe²⁺1.01 to 1.3 equivalents. When the amount is less than 1.01 equivalent, it is difficult to control the alkali addition ratio, and in some cases, the equivalent ratio may be less than 1.0, and it is also difficult to control the particle size and the like. When the amount exceeds 1.3 equivalents, acicular goethite particles are mixed.
[0044]
Further, the reaction temperature is in the temperature range of 45 to 100 ° C. If the reaction temperature is lower than 45 ° C, acicular goethite particles may be mixed. Generates but is not economical.
[0045]
The amount of Mn that coats the Mn hydroxide or the Mn and Fe hydroxide on the particle surface of the octahedral magnetite particles is 8 to 150 atomic% based on the total Fe in the suspension. is there. When Mn is less than 8 atomic%, a nonmagnetic pigment powder can be obtained, but a desired blackness is hardly obtained. If it exceeds 150 atomic%, the desired blackness can be obtained, but the blackness is saturated and there is no point in containing more than necessary. It is preferably in the range of 10 to 100 atomic%, and more preferably in the range of 15 to 50 atomic%.
[0046]
If necessary, Fe and Fe together with Mn²⁺Is added to facilitate the coating of Mn on the surface of the magnetite particles.²⁺Is less than 25 atomic% based on the total Fe in the suspension, and when it exceeds 25 atomic%, a nonmagnetic black pigment powder can be obtained, but the blackness is slightly inferior.
[0047]
In addition, Fe to be added²⁺It is desirable to use the same compound as the ferrous salt aqueous solution used for the generation of the magnetite particles. In the coating treatment, an alkali hydroxide aqueous solution may be additionally added. The conditions such as the processing temperature for coating may be the same as the conditions for forming the magnetite particles.
[0048]
As a production method for producing spherical magnetite particles from which the nonmagnetic black pigment powder of the spherical particles is obtained, for example, the technical means disclosed in JP-B-62-51208 can be used.
[0049]
The amount of the aqueous alkali hydroxide solution is determined by adjusting the amount of Fe²⁺0.80 to 0.99 equivalents. When it is less than 0.80 equivalent or more than 0.99 equivalent, it is difficult to produce spherical magnetite particles.
[0050]
In addition, the reaction temperature is in a temperature range of 45 to 100 ° C. If the reaction temperature is lower than 45 ° C, needle-like goethite particles may be present, and if the temperature exceeds 100 ° C, granular magnetite particles are generated. But not economical.
[0051]
The amount of Mn added to the spherical magnetite particles is also 8 to 150 atomic% based on the total Fe in the suspension. It is preferably in the range of 10 to 100 atomic%, and more preferably in the range of 15 to 50 atomic%. The reason is the same as in the case of the octahedral magnetite particles.
[0052]
The amount of the alkali hydroxide added to coat Mn and the hydroxide of Fe is determined by the amount of the added Mn compound and the amount of the remaining Fe.²⁺Is more than 1.00 equivalent. If less than 1.00 equivalent, Mn and Fe²⁺Cannot be uniformly coated because the entire amount does not precipitate. When it exceeds 1.00 equivalent, it is preferably 1.01 to 1.3 equivalent in consideration of economy.
[0053]
The alkali hydroxide aqueous solution to be added is desirably the same as the alkali hydroxide aqueous solution used to generate the magnetite particles, and the conditions such as the treatment temperature for coating are the same as the conditions for generating the magnetite particles. Good.
[0054]
The oxidizing means for the reaction can be carried out by aerating an oxygen-containing gas (for example, air) through the reaction suspension, and is preferably carried out in a reactor equipped with a stirring function.
[0055]
The magnetite particles coated with a hydroxide of Mn or a hydroxide of Mn and Fe are then heated in a temperature range of 750 to 1000 ° C. to obtain a granular material having a hematite structure containing iron as a main component containing Mn. Get the particles. If it is lower than 750 ° C., the degree of blackness is insufficient, and if it is higher than 1000 ° C., the particles become too large and no coloring power is obtained.
[0056]
Note that the heating and firing are performed in the air. The heating and firing in the air is for oxidizing the magnetite to transform it into a hematite structure.
[0057]
In addition, a metal compound such as Si, Al, P, B, Cu, Zn, Cr, Co, Sn, Cd, V, and Mo may be added before or during the reaction in both of the above production methods. The surface of the magnetite particles coated with the hydroxide of Mn or the hydroxide of Mn and Fe after the reaction may be coated with the metal compound to form the particle shape or maintain the particle shape.
[0058]
The granular particles having a hematite structure containing iron as a main component containing Mn are then coarsely pulverized in a dry system to loosen the coarse particles, then slurried, and then further wet-pulverized to further coarse particles. Relax. The wet pulverization may be performed using a ball mill, a sand grinder, a Dyno mill, a colloid mill, or the like so that coarse particles of at least 44 μm or more are eliminated. The degree of wet pulverization is 10% or less, preferably 5% or less, more preferably 0% of coarse particles having a size of 44 μm or more. If coarse particles of 44 μm or more remain in excess of 10%, it is difficult to obtain the treatment effect in the aqueous alkali solution in the next step.
[0059]
The slurry containing granular particles having a hematite structure containing iron as a main component and containing Mn from which coarse particles were removed was adjusted to a pH value of 13 or more by adding an aqueous alkali solution such as sodium hydroxide to the slurry. Thereafter, heat treatment is performed at a temperature of 80 ° C. or higher.
[0060]
The concentration of the alkaline suspension having a pH value of 13 or more containing granular particles having a hematite structure containing iron as a main component and containing Mn is preferably from 50 to 250 g / l.
[0061]
When the pH value of the alkaline suspension containing granular particles having a hematite structure containing iron as a main component containing Mn is less than 13, the soluble sodium salt present inside the particles and on the surface of the particles, soluble sulfuric acid, Washing out salt etc. becomes insufficient. The upper limit is a pH value of about 14. Considering the effect of washing out soluble sodium salts, soluble sulfates, etc., and the washing effect for removing alkalis such as sodium adhering to the particle surface during the treatment with the alkaline aqueous solution, the pH value is 13.1 to 13. .8 is preferred.
[0062]
The heating temperature of the alkaline aqueous solution having a pH value of 13 or more and containing granular particles having a hematite structure containing iron as a main component containing Mn is preferably 80 ° C or more, more preferably 90 ° C or more. If the temperature is lower than 80 ° C., washing out of soluble sodium salts and soluble sulfates present inside the particles and on the surface of the particles becomes insufficient. The upper limit of the heating temperature is preferably 103 ° C, more preferably 100 ° C. When the temperature exceeds 103 ° C., an autoclave or the like is required, and the liquid to be treated boils under normal pressure, which is not industrially advantageous.
[0063]
Particles that have been heat-treated in an aqueous alkaline solution are separated by filtration and washed with water in a conventional manner, solubilized sodium salts and soluble sulfates washed out from the inside of the particles and from the particle surface, sodium adhered to the particle surface during the alkaline aqueous solution treatment, etc. Of alkali and then dried.
[0064]
As a water washing method, a method generally used in industry such as a method of washing by decantation, a method of washing by a dilution method using a filter thickener, a method of washing by passing water through a filter press, and the like may be used. Good.
[0065]
In addition, if the soluble sodium salt or soluble sulfate contained in the particles of the granular particles having a hematite structure containing iron as a main component containing Mn is washed out with water, the subsequent steps, for example, Even if a soluble sodium salt or a soluble sulfate adheres to the particle surface of the particles in the coating process described later, it can be easily removed by washing with water.
[0066]
The granular particles heat-treated in an alkaline aqueous solution, if necessary, are subjected to a heat treatment in an alkaline aqueous solution, and then separated by filtration and washed with water in a conventional manner, and then an aluminum hydroxide, an aluminum oxide, and a silicon hydroxide. And at least one of silicon oxides.
[0067]
The coating treatment is performed by adding an aluminum compound, a silicon compound, or both compounds to a water suspension obtained by dispersing a cake, slurry, or dry powder of granular particles heat-treated in an alkaline aqueous solution in an aqueous solution, and mixing and stirring. Or, if necessary, by adjusting the pH value, to adhere the hydroxide of aluminum, the oxide of aluminum, the hydroxide of silicon and the oxide of silicon to the particle surface of the granular particles. Then, the mixture is filtered, washed with water, dried and pulverized. If necessary, a deaeration / consolidation treatment may be performed.
[0068]
As the aluminum compound to be added in the coating treatment, aluminum salts such as aluminum acetate, aluminum sulfate, aluminum chloride, and aluminum nitrate, alkali aluminates such as sodium aluminate, and alumina sol can be used.
[0069]
The amount of the aluminum compound to be added is 0.01 to 50.00% by weight in terms of Al based on the granular particles heat-treated in an aqueous alkaline solution. If it is less than 0.01% by weight, the dispersion in the vehicle is insufficient, and if it exceeds 50.00% by weight, the coating effect is saturated, so that there is no point in adding more than necessary.
[0070]
As the silicon compound to be added in the coating treatment, No. 3 water glass, sodium orthosilicate, sodium metasilicate, colloidal silica and the like can be used.
[0071]
The amount of the silicon compound to be added is as follows:₂It is 0.01 to 50.00% by weight in conversion. If it is less than 0.01% by weight, the dispersion in the vehicle is insufficient, and if it exceeds 50.00% by weight, the coating effect is saturated, so that there is no point in adding more than necessary.
[0072]
When an aluminum compound and a silicon compound are used in combination, the amount in terms of Al and SiO₂It is preferably 0.01 to 50.00% by weight in total with the reduced amount.
[0073]
Next, the paint according to the present invention will be described.
[0074]
The mixing ratio of the non-magnetic black pigment powder in the paint according to the present invention can be used in the range of 0.1 to 200 parts by weight with respect to 100 parts by weight of the paint constituting base material, and in consideration of the handling of the paint, Preferably it is 0.1 to 100 parts by weight, more preferably 0.1 to 50 parts by weight.
[0075]
In the present invention, a resin, a solvent, and, if necessary, an extender, a drying accelerator, a surfactant, a curing accelerator, an auxiliary agent, and the like are blended as the paint constituting base material.
[0076]
As the resin, an acrylic resin, an alkyd resin, a polyester resin, a polyurethane resin, an epoxy resin, a phenol resin, a melamine resin, an amino resin, and the like, which are generally used for solvent-based paints, can be used. For water-based paints, commonly used water-soluble alkyd resins, water-soluble melamine resins, water-soluble acrylic resins, and water-soluble urethane emulsion resins can be used.
[0077]
As the solvent, toluene, xylene, butyl acetate, methyl acetate, methyl isobutyl ketone, butyl cellosolve, ethyl cellosolve, butyl alcohol, aliphatic hydrocarbon, and the like, which are usually used for solvent-based paints, can be used.
[0078]
For water-based paints, butyl cellosolve, butyl alcohol and the like which are usually used in addition to water can be used.
[0079]
Examples of the defoaming agent include Nopco 8034 (trade name), SN Deformer 477 (trade name), SN Deformer 5013 (trade name), SN Deformer 247 (trade name), SN Deformer 382 (trade name) (all of which are San Nopco) Commercial products such as Antihome08 (trade name), Emulgen 903 (trade name) (all manufactured by Kao Corporation) can be used.
[0080]
Next, the rubber / resin composition according to the present invention and a method for producing the same will be described.
[0081]
The compounding ratio of the nonmagnetic black pigment powder in the rubber / resin composition according to the present invention can be used in the range of 0.01 to 200 parts by weight with respect to 100 parts by weight of the constituent base material. Taking into account the handling, the amount is preferably 0.05 to 100 parts by weight, more preferably 0.1 to 50 parts by weight.
[0082]
As the constituent substrate in the rubber or resin composition according to the present invention, together with a non-magnetic black pigment powder and rubber or a known thermoplastic resin, if necessary, a lubricant, a plasticizer, an antioxidant, an ultraviolet absorber, and various stabilizers And the like.
[0083]
The amount of the additive may be 50% by weight or less based on the total amount of the non-magnetic black pigment powder and the rubber or thermoplastic resin. When the content of the additive exceeds 50% by weight, the moldability decreases.
[0084]
The rubber or resin composition according to the present invention is obtained by thoroughly mixing the rubber or resin raw material and the non-magnetic black pigment powder in advance, and then applying a strong shearing action under heating using a kneader or an extruder to obtain a black pigment. After agglomeration of the powder is broken and the black pigment powder is uniformly dispersed in the rubber or resin, the powder is molded into a shape suitable for the purpose and used.
[0085]
BEST MODE FOR CARRYING OUT THE INVENTION
A typical embodiment of the present invention is as follows.
[0086]
The average particle size of the black pigment was determined by measuring the directional diameter of about 350 particles shown in a photograph (× 80000) obtained by enlarging the electron micrograph (× 20000) four times in the vertical and horizontal directions, respectively. The average value was shown.
[0087]
The geometric standard deviation (σg) of the particle diameter was shown by a value obtained by the following method. That is, the value of the particle size shown in the enlarged photograph, the particle size of the particle on the horizontal axis on the lognormal probability paper according to a statistical method from the actual particle size and the number of particles calculated from the measured value The diameter is plotted on the vertical axis as a percentage of the cumulative number of particles belonging to each of the predetermined particle diameter sections (under the integrated screen). Then, the particle diameter values corresponding to the cumulative number of particles of 50% and 84.13% are read from this graph, and the geometric standard deviation (σg) = particle diameter at 84.13% below the integrated screen / integrated screen. The value was calculated according to the particle diameter (geometric mean diameter) at the lower 50%. The smaller the geometric standard deviation value, the better the particle size distribution of the particle diameter of the particles.
[0088]
The specific surface area was indicated by a value measured by the BET method.
[0089]
The amounts of Mn, Al and Si present in the inside and on the surface of the black pigment powder were determined by using a fluorescent X-ray analyzer 3063 type (manufactured by Rigaku Corporation) according to JIS.
The measurement was performed in accordance with K0119 “General rules for X-ray fluorescence analysis”.
[0090]
The powder pH value was determined by weighing 5 g of the sample into a 300 ml Erlenmeyer flask, adding 100 ml of boiled pure water, heating and maintaining the boiling state for about 5 minutes, and then stoppering and cooling to room temperature. Open the stopper, add pure water corresponding to the weight loss, stopper again, shake for 1 minute, leave for 5 minutes, measure the pH of the obtained supernatant according to JIS Z 8802-7, and obtain the obtained value. Was taken as the powder pH value.
[0091]
For the content of the soluble sodium salt and the content of the soluble sulfate, the supernatant prepared for the measurement of the pH value of the powder described above was No. 1; The solution was filtered using 5C filter paper, and the Na in the filtrate was filtered.⁺And SO₄ ^2-Was measured using an inductively coupled plasma emission spectrometer (manufactured by Seiko Instruments Inc.).
[0092]
The hue of the black pigment powder was prepared by kneading 0.5 g of a sample and 0.7 cc of castor oil with a Hoover-type muller into a paste, adding 4.5 g of clear lacquer to the paste, kneading and converting the paste into 6 mils on a cast-coated paper. A coated piece (coating thickness: about 30 μm) was prepared using an applicator described in JIS Z8729 using a multi-light source spectrophotometer MSC-IS-2D (manufactured by Suga Test Instruments Co., Ltd.). The color index L according to^*Value, a^*Value, b^*The values were shown as measured values.
[0093]
Similarly, for the hue of the paint using the black pigment powder, the hue of the coating film using the paint having the composition described below, and for the hue of the resin composition, the hue of the resin plate having the composition described below, multi-source spectral colorimetry. Colorimetric index L according to JIS Z8729 using MSC-IS-2D (manufactured by Suga Test Instruments Co., Ltd.)^*Value, a^*Value, b^*The values were shown as measured values.
[0094]
Note that a^*The value represents reddishness, and a larger value indicates a stronger reddishness. b^*The value represents yellowish color, and a larger value means a stronger yellowish color. L^*The value represents lightness.
[0095]
The heat resistance of the black pigment powder was measured by placing 10 g of the sample in a porcelain crucible, performing a heat treatment at 500 ° C. for 3 hours using an electric furnace, and after cooling, measuring the hue of the sample powder. It is determined by measuring a change in hue, and ΔE represented by the following equation based on the colorimetric value before the heat treatment:^*Indicated by. ΔE^*The smaller the value, the smaller the change in hue and the higher the heat resistance.
ΔE^*= ｛(ΔL^*)²+ (Δa^*)²+ (Δb^*)²｝^1/2
Where ΔL^*: L between samples to be compared^*Value difference
Δa^*: A between samples to be compared^*Value difference
Δb^*: B between samples to be compared^*Value difference
[0096]
The remaining amount of the sieve after the wet pulverization is determined by separately obtaining the slurry concentration after the wet pulverization, and passing a slurry equivalent to 100 g of the solid content of the black pigment powder through a 325 mesh (opening 44 μm) sieve. It was determined by quantifying the amount of remaining solids.
[0097]
The dispersibility in the paint vehicle was examined by the glossiness of the coated surface of a coating film produced in the same manner as in the embodiment of the invention described later.
[0098]
The gloss was measured by measuring gloss at 20 ° using a gloss meter UGV-5D (manufactured by Suga Test Instruments Co., Ltd.). The higher the gloss value, the better the dispersibility.
[0099]
The paint viscosity was measured by using an E-type viscometer (cone-plate viscometer) EMD-R (manufactured by Tokyo Keiki Co., Ltd.) at 25 ° C. of the paint prepared according to the formulation described below, and the shear rate D = 1 .92 sec^-1The values in are shown.
[0100]
The dispersibility in the resin composition was determined by visually determining the number of undispersed aggregated particles on the surface of the obtained resin composition, and evaluated on a five-point scale. 5 indicates that the dispersion state is the best.
5: No undispersed substance is observed.
4: 1cm²1 to 4 pieces are recognized per hit.
3: 1cm²There are 5 to 9 per hit.
2: 1cm²There are 10-49 per hit.
1: 1cm²More than 50 are found per hit.
[0101]
The acid resistance is a coating produced by applying a coating using a black pigment powder obtained in Examples described later to a cold-rolled steel plate (0.8 mm × 70 mm × 150 mm: JIS G-3141) at a thickness of 150 μm and drying. A sample having a film is prepared, and the gloss and hue are measured. Next, a 5 wt% sulfuric acid aqueous solution is put into a 1000 cc beaker, the sample is hung with a thread, immersed to a depth of about 120 mm, and left at 25 ° C. for 24 hours.
[0102]
Next, the sample is taken out from the aqueous sulfuric acid solution, gently washed with running water, and the water is shaken off. Then, the gloss and the hue of the central portion of the sample are measured. The change in gloss (ΔG value) and the change in hue (ΔL) before and after immersion in an aqueous sulfuric acid solution.^*Value: L between samples^*ΔG value and ΔL were evaluated for acid resistance according to the magnitude of the difference.^*The smaller the value, the better the acid resistance.
[0103]
The aging resistance is determined by heating a colored resin plate (length 15 mm × width 15 mm × thickness 1 mm) kneaded with black pigment powder obtained in Examples and the like described below at 190 ° C. in a portion where the resin is discolored and deteriorated. Measured value of area S and area S of surface of colored resin plate before heating₀(15mm x 15mm = 2.25cm²) And S / S₀Was determined by quantifying in 5% increments.
That is, (S / S₀) × 100 is 0%, indicating that there is no deterioration, and (S / S₀When x) is 100%, it indicates that the resin is completely degraded.
[0104]
<Manufacture of magnetite particles>
300 l of an aqueous solution of ferrous sulfate having a concentration of 1.40 mol / l are added to 210 l of water and 60 l of a 15.75N aqueous solution of sodium hydroxide prepared in a reactor equipped with a stirrer at a pH value of 13 or more at a temperature of 85 ° C. An aqueous ferrous salt solution containing ferrous hydroxide was produced.
[0105]
250 l of air per minute was passed through the aqueous ferrous salt solution containing ferrous hydroxide at 90 ° C. for 90 minutes to produce magnetite particles.
[0106]
Next, 100 l of a 1.4 mol / l ferrous sulfate aqueous solution and 100 l of a manganese sulfate aqueous solution containing 1.4 mol / l were added to 570 l of an aqueous suspension containing 32.4 kg of the magnetite particles (Mn content was Fe and Mn). 20% by atom) and 50 l of a 11.2N aqueous sodium hydroxide solution (the amount of added Mn and the added Fe).²⁺It corresponds to the amount that neutralizes the amount. ) Was added, and 700 l / min of air was passed through at 180 ° C for 180 minutes at a temperature of 90 ° C and a pH value of 13 or more to produce magnetite particles coated with hydroxides of Mn and Fe. The produced particles were separated by filtration, washed with water, dried and pulverized by a conventional method to obtain a black powder.
[0107]
Subsequently, the obtained black powder was passed through a continuous electric furnace having a ceramic furnace tube to give an average residence time of 900 ° C. in air for 60 minutes to obtain a black powder.
[0108]
The obtained black powder was granular particles having an average particle diameter of 0.30 μm and a geometric standard deviation of the particle diameter of 1.39, as shown in the electron microscope (× 20000) in FIG. 1, and a BET specific surface area value of 3.8m²/ G. As a result of X-ray fluorescence analysis, the Mn content was 13.8% by weight, the powder pH was 7.4, the soluble sodium salt content was 712 ppm in terms of Na, and the soluble sulfate content was SO.₄856 ppm in conversion and its hue is L^*Value 22.10, a^*Value 0.21, b^*The value was -1.31.
[0109]
As a result of X-ray diffraction, a hematite peak was observed. As for magnetism, the magnetization value when an external magnetic field of 10 kOe was applied was 0.31 emu / g, which was almost the same as that of hematite.
[0110]
Further, a heat resistance test was performed on 10 g of the black powder, and the hue of the black powder after the heat treatment was L^*Value 22.08, a^*Value 0.16, b^*The value was −1.26, and the heat resistance ΔE was 0.07, indicating that the heat resistance was excellent.
[0111]
<Alkali heat treatment of black pigment powder>
Next, 20 kg of the black powder was contacted with 150 l of pure water using a stirrer, and further passed through a homomic line mill (manufactured by Tokushu Kika Kogyo Co., Ltd.) three times to obtain a slurry of the black powder.
[0112]
Subsequently, the obtained black slurry was passed five times at a shaft rotation number of 2000 rpm using a horizontal SGM (Mighty Mill: manufactured by Inoue Seisakusho Co., Ltd.). The sieve residue of the black powder in the obtained slurry at 325 mesh (mesh size: 44 μm) was 0%.
[0113]
The concentration of the obtained black powder slurry was set to 100 g / l, and 150 l of the slurry was collected. While stirring the slurry, a 6N aqueous solution of sodium hydroxide was added to adjust the pH value of the slurry to 13.1. Subsequently, the slurry was heated with stirring and heated to 95 ° C., and kept at that temperature for 3 hours.
[0114]
Next, this slurry was washed with water by a decantation method to obtain a slurry having a pH value of 10.5. For the sake of accuracy, the slurry concentration was confirmed at this point to be 99 g / l. 50 l of this slurry was separated, filtered and dried to obtain a black powder (A).
[0115]
The obtained black powder is granular particles having an average particle diameter of 0.30 μm and a geometric standard deviation of the particle diameter of 1.39, as shown in the electron microscope (× 20000) in FIG. 4.1m²/ G. As a result of X-ray fluorescence analysis, the Mn content was 13.7% by weight, the powder pH value was 8.6, the soluble sodium salt content was 96 ppm in terms of Na, and the soluble sulfate content was SO.₄The conversion was 32 ppm, and the heat resistance was ΔE of 0.07. The hue is L^*Value is 22.12, a^*Value 0.19, b^*The value was -1.26.
[0116]
As a result of X-ray diffraction, a hematite peak was observed. As for magnetism, the magnetization value when an external magnetic field of 10 kOe was applied was 0.36 emu / g, which was almost the same as that of hematite.
[0117]
<Coating treatment of black pigment powder>
The remaining 100 l of the slurry was heated to 60 ° C., and 3667 ml of a 1.0 mol / l aqueous sodium aluminate solution (corresponding to 1.0 wt% in terms of Al with respect to the black pigment powder) was added to the slurry. After holding for 30 minutes, the pH value was adjusted to 8.0 using acetic acid. After maintaining in this state for 30 minutes, 685.1 g of an aqueous solution of No. 3 water glass (SiO.₂This corresponds to 2.0% by weight in conversion. ) Was added and the mixture was kept for 30 minutes, and then the pH value was adjusted to 7.5 with acetic acid. Next, it was filtered, washed with water, dried and pulverized to obtain a black powder (B) composed of black particles whose surface was coated with an aluminum hydroxide and a silicon oxide.
[0118]
As a result of electron micrograph observation, the obtained black powder was granular particles having an average particle diameter of 0.30 μm and a geometric standard deviation of the particle diameter of 1.39, and a BET specific surface area of 11.2 m.²/ G. As a result of X-ray fluorescence analysis, the Mn content was 13.5% by weight, the Al content was 0.97% by weight,₂The content was 1.93% by weight, the powder pH value was 8.1, the soluble sodium salt content was 123 ppm in terms of Na, and the soluble sulfate content was SO.₄The conversion was 78 ppm, and the heat resistance ΔE was 0.1. The hue is L^*Value 22.31, a^*Value 0.37, b^*The value was -1.31. Further, as a result of X-ray diffraction, a peak indicating a hematite structure was observed.
[0119]
<Manufacture of paint using black pigment powder>
Using 10 g of each of the black pigment powders (A) and (B) in a 140 ml glass bottle, the coating composition was blended at the following ratio, and mixed and dispersed with 90 g of 3 mmφ glass beads for 90 minutes using a paint shaker to prepare a mill base.
[0120]
The coating composition obtained was as follows.
12.2 parts by weight of black pigment powder (A) or (B)
Amino alkyd resin 19.5 parts by weight
(Amilac No. 1026: manufactured by Kansai Paint Co., Ltd.)
7.3 parts by weight of thinner
[0121]
Using the above-mentioned mill base, the paint compositions were blended in the following proportions, mixed and dispersed for further 15 minutes with a paint shaker, and paint (A) containing black pigment powder (A) and paint (B) containing black pigment powder (B) ) Got.
[0122]
The coating composition obtained was as follows.
Mill base 39.0 parts by weight
Amino alkyd resin 61.0 parts by weight
(Amilac No. 1026: manufactured by Kansai Paint Co., Ltd.)
[0123]
Next, the obtained paint was applied to a cold-rolled steel plate (0.8 mm × 70 mm × 150 mm: JIS G-3141) with a thickness of 150 μm and dried.
[0124]
The coating film produced using the paint (A) has a glossiness of 96% and a hue of L^*Value is 22.81, a^*Value 0.41, b^*The value was -1.49, the gloss change ΔG value based on the acid resistance test of the coating film was 3.8%, and the lightness change ΔL^*The value was 0.31.
[0125]
The coating film produced using the paint (B) has a glossiness of 105% and a hue of L^*Value is 22.76, a^*Value 0.37, b^*Value is -1.51, gloss change ΔG value based on acid resistance test of coating film is 2.1%, lightness change ΔL^*The value was 0.10.
[0126]
<Production of resin composition containing black pigment powder>
Using each of the black pigment powders (A) and (B), 1.5 g of the black pigment powder and 48.5 g of polyvinyl chloride resin powder 103EP8D (manufactured by Nippon Zeon Co., Ltd.) were weighed and placed in a 100 cc polybeaker. And mixed well with a spatula to obtain a mixed powder.
[0127]
To the obtained mixed powder, 0.5 g of calcium stearate was added and mixed, the clearance of a hot roll heated to 160 ° C. was set to 0.2 mm, and the mixed powder was kneaded little by little into a roll to obtain a resin composition. After kneading was continued until the resin was integrated, the resin composition was peeled off from the roll and used as a colored resin plate raw material.
[0128]
Next, the above resin composition was sandwiched between stainless steel plates whose surfaces were polished, and placed in a hot press heated to 180 ° C., and 1 ton / cm 2²To obtain colored resin plates (A) and (B) having a thickness of 1 mm.
[0129]
The dispersion state of the obtained colored resin plate (A) was 5. Three test pieces obtained by cutting the colored resin plate (A) into 1.5 cm squares were put into a gear oven heated to 190 ° C., and were taken out one by one every 30 minutes. Minutes after the deterioration (S / S₀× 100) was 0%, the degree of resin deterioration after 60 minutes was 5%, and the degree of resin deterioration after 90 minutes was 5%.
[0130]
The dispersion state of the obtained colored resin plate (B) was 5. Three test pieces obtained by cutting the colored resin plate (B) into 1.5 cm squares were put into a gear oven heated to 190 ° C., and taken out one by one every 60 minutes. Minutes after the deterioration (S / S₀× 100) was 0%, the degree of resin deterioration after 60 minutes was 0%, and the degree of resin deterioration after 90 minutes was 0%.
[0131]
[Action]
First, the most important point in the present invention is that non-magnetic black granular particles having an average diameter of 0.1 to 10 μm and having a hematite structure containing iron as a main component and containing Mn have a Mn content of 5 to Fe. And the powder pH value is 5.5 or more, the content of soluble sodium salt is 500 ppm or less in terms of Na, and the content of soluble sulfate is SO₄This is the fact that the nonmagnetic black granular particles having a conversion of 200 ppm or less have excellent blackness and heat resistance, and are more excellent in dispersibility.
[0132]
Regarding the reason why the blackness is excellent, the present inventors have found that Mn is not uniformly contained inside the particles, or when the hematite particles are contained only in the surface layer, the blackness is not excellent. By heating and sintering magnetite particles coated with a hydroxide of Mn or a hydroxide of Mn and a hydroxide of Mn in a temperature range of 750 to 1000 ° C., the magnetite is oxidized to change into a hematite structure, and the coated Mn. It is considered that the presence of Mn in the hematite structure is influenced by the excellent blackness of the hydroxide when the hydroxide diffuses from the particle surface into the particle interior.
[0133]
The reason for the excellent heat resistance is that the present inventor believes that the particles having a hematite structure containing iron as a main component and containing Mn are manufactured at a high temperature of 750 ° C. or higher. .
[0134]
Regarding better dispersibility, the present inventor has found that solid sodium crosslinking and soluble sulfate derived from the raw material causing solid crosslinking can be removed by alkali treatment, so that solid crosslinking is unraveled. We believe that the dispersibility was improved because the coagulation was broken.
[0135]
Next, an important point in the present invention is that a paint or a rubber / resin composition obtained by using the particles having a hematite structure containing iron as a main component and containing Mn according to the present invention has blackness and heat resistance. It is a fact that, of course, the paint has excellent acid resistance, and the rubber / resin composition has excellent aging resistance.
[0136]
Although it is not yet clear why the acid resistance of the paint and the aging resistance of the rubber / resin composition are excellent, the present inventor has proposed a component that inhibits the acid resistance in the black powder after the heat treatment, for example, a raw material. It is believed that the soluble sodium salts and soluble sulfates derived from ash could be removed by alkali treatment.
[0137]
【Example】
Next, examples and comparative examples will be described.
[0138]
<Production of black pigment powder>
Examples 1 to 6
Starting materials 1 to 4 were produced in the same manner as in the embodiment of the present invention.
[0139]
Table 1 shows the properties of the obtained starting materials 1 to 4.
[0140]
Using the starting materials 1 to 4, a black pigment powder having a hematite structure containing iron as a main component and containing Mn was produced in the same manner as in the embodiment of the present invention.
[0141]
Table 2 shows the main conditions and various characteristics at this time.
[0142]
[Table 1]

[0143]
[Table 2]

[0144]
Examples 7 to 12
The type of the black powder having a hematite structure containing iron as a main component containing Mn, the presence or absence of wet pulverization, the pH value in the heat treatment in an alkaline aqueous solution, the temperature, and time were variously changed, except for the present invention. An alkaline aqueous solution-treated black pigment powder was obtained in the same manner as in the embodiment.
[0145]
Table 3 shows the main manufacturing conditions and various characteristics at this time.
[0146]
[Table 3]

[0147]
Examples 13 to 18
Each of the black pigment powders of Examples 7 to 12 was used, and except that the type and amount of the surface coating were variously changed, the black particles whose surfaces were coated with the coating in the same manner as in the embodiment of the present invention. A black pigment powder composed of particles was obtained.
[0148]
Table 4 shows the main manufacturing conditions and various characteristics at this time.
[0149]
[Table 4]

[0150]
Comparative Examples 1 to 10
Comparative Examples 1 to 3 which are black pigment powders having a hematite structure mainly containing iron containing Mn before alkali treatment, Comparative Examples 4 to 7 which are known black pigment powders, and Mn after alkali treatment Comparative Examples 8 to 10 which were black pigment powders having a hematite structure containing iron as a main component were prepared.
[0151]
Tables 5 and 6 show the properties of these black pigment powders.
[0152]
The Mn solid solution iron oxide pigment powder of Comparative Example 7 was produced according to the production method described in Japanese Patent Application Laid-Open No. 8-143316.
[0153]
[Table 5]

[0154]
[Table 6]

[0155]
<Manufacture of paint>
Examples 19 to 30 and Comparative Examples 11 to 20
A coating material was produced in the same manner as in the embodiment of the present invention except that the type of the black pigment powder was variously changed, and a coating film was formed.
[0156]
Tables 7 and 8 show the main production conditions and coating film properties at this time.
[0157]
[Table 7]

[0158]
[Table 8]

[0159]
<Production of resin composition>
Examples 31 to 42 and Comparative Examples 21 to 30
A resin composition was obtained in the same manner as in the embodiment of the present invention, except that the type of the black pigment powder was variously changed.
[0160]
Tables 9 and 10 show the main production conditions and various characteristics at this time.
[0161]
[Table 9]

[0162]
[Table 10]

[0163]
【The invention's effect】
The non-magnetic black pigment powder according to the present invention has excellent blackness and heat resistance, and is more excellent in dispersibility, so that it is suitable as a coloring material and a filler for a coating material, a rubber / resin composition. is there.
[0164]
The paint according to the present invention can obtain a coating film having excellent blackness and excellent acid resistance due to the use of the non-magnetic black pigment powder having the above-mentioned various properties.
[0165]
The rubber / resin composition according to the present invention is excellent in blackness and is excellent in aging resistance due to the use of the nonmagnetic black pigment powder having the above-mentioned various properties. Can be obtained.
[Brief description of the drawings]
FIG. 1 is an electron micrograph (× 20000) showing the particle structure of a black pigment powder having a hematite structure containing iron as a main component and containing Mn before alkali treatment obtained in an embodiment of the present invention. is there.
FIG. 2 is an electron microscope showing a particle structure of a black pigment powder after heat treatment with an alkaline aqueous solution having a hematite structure containing iron as a main component and having a main component of Mn and obtained before an alkali treatment, obtained in an embodiment of the present invention. It is a photograph (x20000).

Claims (3)

The Mn content of nonmagnetic black granular particles having an average diameter of 0.1 to 10 μm and having a hematite structure containing iron as a main component and containing Mn is 5 to 40% by weight based on the nonmagnetic black pigment powder. A non-magnetic black powder having a powder pH value of 5.5 or more, a soluble sodium salt content of 500 ppm or less in terms of Na, and a soluble sulfate content of 200 ppm or less in terms of SO _4. A non-magnetic black pigment powder, characterized in that:

2. The main component is iron containing Mn, the surface of which is coated with at least one of aluminum hydroxide, aluminum oxide, silicon hydroxide and silicon oxide. The Mn content of nonmagnetic black granular particles having a hematite structure and having an average diameter of 0.1 to 10 μm is 5 to 40% by weight with respect to the nonmagnetic black pigment powder, and the powder pH value is 5.5 or more. Te, and, following 500ppm in a content of Na in terms of soluble sodium salt, a non-magnetic black pigment powder, wherein the content of soluble sulfate salt is a non-magnetic black powder is 200ppm or less in terms _of SO _4. 3. A non-magnetic black paint, wherein the non-magnetic black pigment powder according to claim 1 or 2 is blended in a paint constituting base material. 3. A non-magnetic black rubber / resin composition comprising the non-magnetic black pigment powder according to claim 1 or 2 incorporated in a rubber / resin composition constituent substrate.

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