JPS6343962A - Mica/titanium composite material - Google Patents

Abstract

PURPOSE:To provide the title composite material having excellent brightness, chroma, safety, electrical conductivity, magnetic characteristics and resistance to chemicals, solvents and heat, by coating the surface of mica with TiO2 and specified metallic particles. CONSTITUTION:Mica having a particle size of 1-50mu is added to an aq. soln. of a titanium compd. (e.g., titanyl sulfate). The mixture is heated with stirring and the product is recovered by filtration and dried by heating it at 900 deg.C to obtain mica coated with a TiO2 layer of 200Angstrom or above in thickness. The mica is dispersed in an aq. soln. contg. at least one member selected from the group consisting of strong acids, SnCl2 and PdCl2 to activate the surface of the mica. The activated mica is recovered by filtration and dispersed in an electroless plating bath contg. at least one metal salt selected from the group consisting of CO, Ni, and Cu salts to coat the surface of 100pts.wt. TiO2- coated mica with 0.01-100pts.wt. at least one metal selected from the group consisting of Co, Ni and Cu.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention has excellent color tones such as brightness and chroma, and has excellent stability such as safety, light resistance, chemical resistance, solvent resistance, and heat resistance. Regarding the excellent new mica titanium composite material, it is used in paints, cosmetics,
It is useful as a pigment for plastics, inks, paints, decorative items, daily necessities, textile products, ceramics, etc., and as a colored pearlescent material. It is also useful for conductive materials such as conductive layers and recording layers of recording paper, antistatic materials, and electromagnetic waves. The present invention provides a mica-titanium composite material that is expected to be used as a shielding material.

(Prior Art) Mica-titanium composite materials, in which the surface of mica is coated with titanium dioxide, have pearlescent luster and various interference colors, and are therefore widely used as pigments in cosmetics, paints, plastics, and the like. Vacuum deposition is a method for producing it, but as described in DuPont's patent (Japanese Patent Publication No. 43-25644), an aqueous solution of an inorganic acid salt of titanium (for example, titanyl sulfate) is hydrolyzed in the presence of mica. A common method is to precipitate hydrated titanium dioxide on the surface and then heat it. The mica used is generally muscovite mica (mu
scovite m1ca), but depending on the case, it is also possible to use biotite or the like. In addition, mica is used after it has been pre-filtered with water and the particle shape is made uniform using a sieve. The produced mica-titanium composite material exhibits various interference colors depending on the thickness of the titanium dioxide coating layer on the mica particle surface. The interference color is usually silver when the amount of titanium dioxide is between 10 and 26% of the product, but between 26 and 40%.
In the range of 40 to 50%, the color changes to red, blue, and green as the titanium dioxide layer increases.
~60% gives high order interference colors.

Although these mica-titanium composite materials have pearlescent luster and various pale interference colors, the appearance color is always close to white, and no material exhibiting a bright appearance color that matches the interference color has yet to be obtained.

Conventionally, in order to produce various external colors, colored pigments such as iron oxide, navy blue, chromium oxide, carbon black, and carmine were directly added to or coated on the produced mica-titanium composite materials.

(Problems to be solved by the invention) The safety, light resistance, and
Stability such as chemical resistance, solvent resistance, and heat resistance is determined by the coloring pigment added or coated. For example, navy blue is mainly added to blue mica titanium composite materials, but navy blue fades in an alkaline solution and further
Decomposes and fades at ℃.

Furthermore, a mixture of iron oxide and navy blue or chromium oxide has been added to green mica-titanium composite materials, but these pigments have poor chemical resistance and thermal stability, and furthermore, the safety of chromium has been compromised. However, the scope of its use was limited due to problems. In addition, blue and green organic pigments such as phthalocyanine blue, brilliant blue FCF aluminum lake, quinizarine green, and phthalocyanine green are inferior in stability such as heat saving, light resistance, and chemical resistance, and are hardly used for coloring pearlescent materials. not being used. On the other hand, red mica-titanium composite pigments containing carmine fade and deteriorate when exposed to light. Furthermore, since the above-mentioned colored mica-titanium composite material contains colored face v4, the conventional colored mica-titanium composite material has various drawbacks, such as color separation in a solvent.

(Means for Solving the Problems) As a result of intensive research to improve the drawbacks of the above-mentioned conventional techniques, the present inventors coated the mica surface with titanium dioxide, and then coated the mica surface with titanium dioxide, which was then coated with titanium dioxide selected from cobalt, nickel, and copper. By coating with one or more types of metal particles, color tones such as brightness and saturation are significantly improved, good agreement between appearance color and interference color is achieved, and stability, safety, light resistance, and alkali resistance are achieved. The present inventors have discovered that it is possible to obtain a composite material that has excellent pigment properties such as solvent resistance and heat resistance, as well as excellent conductivity and magnetic properties such as low specific resistance, and has completed the present invention. .

That is, in the present invention, the mica surface is coated with titanium dioxide,
Further, the titanium dioxide-coated mica surface is a mica-titanium composite material in which the surface of the mica coated with titanium dioxide is coated with one or more metal particles selected from cobalt, nickel, and copper.

Next, the configuration of the present invention will be explained in detail.

The mica used in the present invention may be any type of mica, and is generally commercially available muscovite mica (museovitemi).
ca), but depending on the case, it is also possible to use biotite or the like. There are no particular restrictions on the particle size, but when using it as a pearlescent pigment, mica with a smaller particle size and as flat a particle shape as possible among commercially available mica (particle diameters of about 1 to 50 μm) is best for beautiful color tone and pearlescent luster. This is preferable because it is easy to demonstrate.

In the mica-titanium composite material of the present invention, the mica surface is coated with titanium dioxide, and the titanium dioxide-coated mica surface is further coated with one or more metal particles selected from cobalt, nickel, and copper. The content of metal particles is 0.01 to 100 parts by weight, preferably 1 to 60 parts by weight, based on 100 parts of mica. If the metal particle content is less than 1 part by weight, the mica obtained will have an interference color, but it will be difficult to obtain an appearance color that matches this, and if it exceeds 60 parts by weight, the blackening of the particles will be noticeable, which is not preferable. .

Further, in the present invention, the total amount of titanium dioxide coated on the mica is preferably 200 angstroms or more in thickness, and furthermore, when trying to obtain an excellent appearance color and interference color of a tone other than black, is preferably 900 angstroms or more.

In the mica-titanium composite material of the present invention, the mica surface is coated with titanium dioxide, and the mica surface coated with titanium dioxide is selected from cobalt, nickel, and copper. This product is coated with one or more types of metal particles, and various methods can be used to manufacture this product. For example, a commercially available titanium mica pigment is dispersed in an aqueous solution of one or more selected from strong acids, tin chloride, and palladium chloride to activate the titanium mica surface. After filtration, the activated titanium mica is dispersed in an electroless plating bath, and the surface of the activated titanium mica is uniformly coated with metal particles. At this time, since the electroless plating bath reduces and precipitates metal from a metal salt solution using a reducing agent, it contains a metal salt and a reducing agent, but it also contains other components necessary for preparing the solution (- (salt) is also included. Examples include complexing stabilizers and buffering agents.

The metal salt serves as a supply source for the plating metal, and any soluble salt may be used, such as cobalt, nickel, copper sulfates, hydrochlorides, nitrates, carbonates, etc. Any one or more of them can be used.

In addition, as a reducing agent, sodium hypophosphite, sodium hyposulfite,
Anhydrous sodium sulfite, hydrazine chloride, hydrazine sulfate,
Examples include hydrazine oxalate, anhydrous sodium sulfite, hydroquinone, hydrosalofide tartrate, formalin, sucrose, monosaccharides, glyogyzal, and any one or more of these may be used.

Complexation stabilizers are used to prevent the natural decomposition of metal salts in the form of complex salts or chelates, stabilize them, and make it easier for metals to precipitate. oxidizing agent, triethanolamine, EDTA
Any one or more chelating agents selected from the following chelating agents may be used.

Buffers include organic acids such as acetic acid, tartaric acid, citric acid, and gluconic acid, their sodium, potassium, and ammonia salts, or sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, etc. Any one or more of these may be used.

Furthermore, an aqueous solution of an inorganic acid salt of titanium as described in DuPont's patent (Japanese Patent Publication No. 43/25644) is hydrolyzed in the presence of the mica described above to precipitate hydrated titanium dioxide on the surface of mica particles, and then Examples include a method of coating metal particles by the electroless plating method described above, or a method of precipitating hydrous titanium dioxide on the surface of mica particles, heating to generate titanium mica, and then coating the metal particles by the electroless plating method described above. It will be done.

The hydrated titanium dioxide and/or
Or the amount of titanium dioxide, the type of metal to be electrolessly plated,
By selecting the amount (ratio), pH1 reaction temperature, etc.
A mica-titanium composite material exhibiting desired physical properties such as external color, magnetism, and electrical conductivity can be obtained.

The mica titanium composite material of the present invention has great effects such as excellent color tone such as brightness and saturation, and excellent safety, weather resistance, light resistance, chemical resistance, solvent resistance, and heat resistance. It is useful as a pigment for paints, cosmetics, plastics, inks, paints, decorative items, daily goods, textile products, ceramics, etc., and as a colored burl gloss material, and as a conductive layer of recording paper, a recording layer, It also has great industrial utility value, with potential applications as conductive materials such as anti-static materials and electromagnetic shielding materials.

(Example) Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

However, the present invention is not limited thereto.

Example 1 Cloud 1 so8 was added to ion exchange water 5008 and thoroughly stirred to uniformly disperse it. 208.5 g of an aqueous titanyl sulfate solution having a concentration of 40% by weight was added to the obtained dispersion, and the mixture was heated with stirring and boiled for 3 hours. After cooling, rinse with filtered water,
It was dried at 900° C. to obtain 80 g of mica coated with titanium dioxide (titanium mica).

Next, 50 g of the obtained mica titanium was dispersed in 500 ml of an 8X10 M tin chloride aqueous solution, and after filtration, 5X10 M
It was again dispersed in 500 ml of palladium chloride aqueous solution. 50 g of activated mica titanium obtained after filtration was adjusted to pH 8-1.
0. Sodium hypophosphite (27g) kept at a bath temperature of 90℃
Electroless cobalt plating bath 95 consisting of L cobalt sulfate (47 g/l), Lotussel salt (268 g/l),
0ml for 1 hour. After filtering and washing with water, it was dried at 150° C. to obtain 53 g of a blue pearlescent material with bright appearance and interference colors.

The surface of the particles of this product, the blue pearlescent material, is as shown in the scanning electron micrograph of FIG. According to this, it is possible to observe that the surface of each particle of the product, the blue pearlescent material, is sufficiently covered with the fine rod-shaped powder. This product also has a blue pearlescent material called X.
The line diffraction diagram (α line for Cu-) is as shown in Figure 2,
According to this, in addition to the diffraction peak of mica, a peak is observed around a diffraction angle (Bragg angle 20) of 25.3°. This corresponds to the strongest peak (101) of anatase titanium dioxide.

Furthermore, the amount of metallic cobalt coating the surface of the mica titanium particles was determined by the method shown below.

First, the obtained blue pearlescent material (sample) was pulverized using an agate ball mill to make the mica amorphous, and the amorphous sample was subjected to fluorescence Xlj;1 measurement to show α52. The intensity at 18° was determined, and the amount of metallic cobalt was determined by comparing the intensity with a separately determined diffraction intensity calibration curve of a known mixing ratio of mica and metallic cobalt. Further, the amount of titanium dioxide in the obtained blue pearlescent material was determined by the following method.

First, the obtained blue pearlescent material (sample) was pulverized using an agate ball mill, the mica was made amorphous, and the amorphous sample was measured by X-ray diffraction (α rays on Cu-) powder measurement method. The intensity of diffraction of titanium dioxide was determined, and the amount of titanium dioxide was determined by comparing the intensity with a calibration curve of diffraction intensity of a known mixing ratio of mica and titanium dioxide, which was obtained separately.
.

This blue pearlescent material contains 48 parts by weight based on 100 parts by weight of mica.
．． It was coated with 2 parts by weight of titanium dioxide and 16.3 parts by weight of metallic cobalt.

Example 2 50 g of Cloud 11Q was added to 500 g of ion-exchanged water and thoroughly stirred to uniformly disperse the mixture. The resulting dispersion has a concentration of 4
312.58 g of an aqueous solution of titanyl sulfate of 1% by weight was added, and the mixture was heated with stirring and boiled for 8 hours. After cooling, it was filtered, washed with water, and dried at 900° C. to obtain 100 g of mica coated with titanium dioxide (mica titanium).

Next, 50 g of the obtained mica titanium was dispersed in 500 ml of 8X10-3M tin chloride aqueous solution, and after filtration, 5X10-
It was again dispersed in 500 ml of 4M palladium chloride aqueous solution. 50 g of activated mica titanium obtained after filtration was adjusted to pH 8.
~10, Sodium hypophosphite kept at a bath temperature of 80℃ (
10g/l), sodium citrate (100g/l),
Ammonium chloride (508/1), nickel chloride (30
Electroless nickel plating bath consisting of 1200 g/l)
ml, then formalin (35%) was added to 120
After adding 0ml, the mixture was further dispersed for 1 hour.

After filtering and washing with water, it was dried at 150° C. to obtain 54 g of a green pearlescent material with bright appearance color and interference color.

Next, the quantitative ratio of titanium dioxide and metallic nickel coating the mica surface in the green pearlescent material, which is the product obtained in this example, was determined in the same manner as in Example 1.

This green pearlescent material contains 12 parts by weight per 100 parts by weight of mica.
It was coated with 0 parts by weight of titanium dioxide and 16.2 parts by weight of metallic nickel.

Example 3 50 g of mica was added to ion-exchanged water 5008 and sufficiently stirred to uniformly disperse it. '8!2 degrees 4 to the obtained dispersion
208.5 g of a 0% by weight titanyl sulfate aqueous solution was added, and the mixture was heated while stirring and boiled for 3 hours. After cooling, it was filtered, washed with water, and fired at 900° C. to obtain 90 g of mica coated with titanium dioxide (titanium mica).

Next, 5CLg of the obtained mica titanium was dispersed in 500ml of 8X10-3M tin chloride aqueous solution, and after filtration, 5CLg of titanium mica was
It was again dispersed in 500 ml of 4M palladium chloride aqueous solution. 50 g of activated mica titanium obtained after filtration was adjusted to pH 1.
1,5, Lotusel salt (1708/I) kept at a bath temperature of 22°C
), sodium hydroxide (50 g/l), sodium carbonate (30@/l), and copper sulfate (35 g/l) for 1 hour in a 1200 ml electroless copper plating bath. After filtering and washing with water, it was dried at 150° C. to obtain 52.6 g of a blue pearlescent material with bright appearance and interference color.

Next, in the blue pearlescent material that is the product obtained in this example, the quantitative ratio of titanium dioxide and metal steel covering the mica surface was determined in the same manner as in Example 1.

This green pearlescent material is 77% by weight based on 100 parts by weight of mica.
．． It was made by coating 4 parts by weight of titanium dioxide and 8.5 parts by weight of metallic steel. Example 4 50g of cloud was added to 500g of ion-exchanged water and thoroughly stirred to uniformly disperse it. 130.0 g of titanyl sulfate aqueous solution having a concentration of 40% by weight was added to the obtained dispersion, and the mixture was heated with stirring and boiled for 3 hours. After cooling, filtered and washed with water, fired at 900°C and coated with titanium dioxide (mica titanium) 100
I got 8.

Next, 50 g of the obtained mica titanium was dispersed in 500 ml of an 8X10-3M tin chloride aqueous solution, and filtered.
It was again dispersed in 500 nl of M palladium chloride aqueous solution. 50g of activated mica titanium obtained by filtration was adjusted to pH 8~
10 Sodium hypophosphite (27g) kept at a bath temperature of 90℃
Electroless cobalt plating bath 5 consisting of Lotussel salt (268 g/l ), cobalt sulfate (47 g/l ), and cobalt sulfate (47 g/l )
It was dispersed in 50ml for 1 hour. 150℃ after filtration and water washing
51.2 g of a pearlescent material with bright red appearance and interference color was obtained. This red pearlescent material is mica 1
00ff! It was coated with 120 parts by weight of titanium dioxide and 9.4 parts by weight of cobalt gold chips.

Next, Table 1 shows the color tones of the mica-titanium composite materials obtained in Examples 1 to 4 of the present invention, which are products of the present invention.

(Margin below) 2 Green 2.30G 4.13/3.293
Blue 4.23B 5.18/3.29 The pigment properties of the mica-titanium composite materials obtained in Examples 1 to 4 were tested. For comparison, a colored mica titanium-based nacreous tear face sold by Marl Corporation in the US! 4 (color added to conventional mica titanium pigment) Pigment properties were tested to seven degrees. As the commercially available colored mica titanium pearlescent pigments for comparison, those corresponding to the color tone of the mica titanium composite materials of Examples 1 to 4 were selected. Table 2 shows commercial product names.

(Leaving space below) Table 2 Products of Example 4 Cloisonne Red Products of Example 1.3 Cloisonne Blue Products of Example 2 Cloisonne Green The compositions of commercially available products are shown in Table 3.

Kroirin Red 36-4256-62
1.5 to 3 kuroiri volume Blue 44 to 4948 to 54 2 to 5
Chloirin Green 44-4844-48 4-7
1-3 (chromium oxide) test items are photostability,
These are thermal stability, dispersion stability, and alkali stability, and the test methods and test results are as follows.

(1) Photostability test The mica-titanium composite material of the present invention and the commercially available colored mica titanium are each mixed with talc (manufactured by Asada Seifun Co., Ltd.) at a ratio of 3 Nia, and 2.5 g of the mixture is mixed with Sa3
mm, molded into a square aluminum medium plate with sides of 20 mm,
Is this a xenon lamp? : Irradiated for 30 hours. The color tone after irradiation and the color tone before irradiation were measured using a color analyzer 607, and the color difference (ΔE) before and after irradiation was determined from the colorimetric values.

(2) Thermal stability test A mica-titanium composite material, which is a product of the present invention, and a commercially available colored mica titanium were each placed in a magnetic crucible of 20 m and 38 cm.
It was weighed and heat-treated in the air at 200°C, 300°C, and 400°C for 2 hours. The color tone after processing and the color tone before processing are measured using a color analyzer 607,
The color difference (ΔE) before and after the treatment was determined from the color embellishment value.

(3) Dispersion stability test 1.0 g each of the mica titanium-based composite material of the present invention and commercially available colored mica titanium, 50 ml with stopper scale.
The mixture was placed in a test tube, and 50 ml of a 0.2% by weight aqueous hexametaphosphoric acid solution was added thereto, dispersed for 30 seconds using a polytron, and further dispersed using ultrasonic waves. After dispersion, the mixture was allowed to stand still in a test tube stand, and the dispersion state was observed with the naked eye immediately after, 5 minutes, 10 minutes, 30 minutes, and 1 hour after standing.

(4) Alkali stability test 1.5 g of each of the mica titanium-based composite material of the present invention and commercially available colored mica titanium were placed in a 50 ml test tube with a stopper scale, and 2N-caustic soda was added to the test tube. 30m1 at night
After dispersion, the mixture was left to stand in a test tube stand, and the color tone after 24 hours was observed with the naked eye.

(Leaving space below) Table 4 Stability test results (light and thermal stability) of mica-titanium-based composite colored pearlescent material, which is a product of the present invention Example Light stability Thermal stability 200°C 300°C 400°C 1 0.2 0.13 0.26 3.
382 0.3 0.1 0,31 4
．． 413 0.3 0.1 0.22
3.354 0.2 0.1 0.21
4.33 Croisonered 35.3
3,5 26,2 45.0 Chloirine Blue-5,23,236,437,2 Cloison Green 6.0 0.2 0.6
7.8 (blank below) Table 5 Stability test results (dispersion stability, alkali stability) of the mica-titanium composite material, which is a product of the present invention, 5 minutes 10 minutes 30 minutes 60 minutes 20 ooo.

3 0000 Q ４　・oooo　　　.

Ria Irinrefed △ △ xx
x Cloison Flu △ △ ××
× Ri U Irine Green O○ Δ ×
△ indicates △ mark: Sedimentation progresses with color separation. Become.

×: Discoloration and change to white (white space below) As is clear from the results in Tables 4 and 5, the mica titanium composite material, which is the product of the present invention, has light stability, thermal stability, dispersion stability, and alkali stability. It is something that has been corrupted by gender. In other words, in terms of photostability, the color difference (ΔE) before and after irradiation remains almost the same at 0.3 or less, and the difference in color tone is almost indistinguishable to the naked eye, whereas the commercially available product shows no obvious change in color tone even with the naked eye. It turns out that

Further, the thermal stability is such that the color difference is 0.4 or less up to 300°C, and the difference in color tone is hardly discernible with the naked eye. At 400° C., there is some discoloration, but this is because the total flexural particles on the surface of mica titanium are oxidized and changed into metal oxides. On the other hand, color tone changes were clearly observed in commercially available products other than Cloisonne Gold.

Regarding the dispersion stability, the mica-titanium composite material, which is the product of the present invention, is uniformly dispersed even after standing for 1 hour.
In commercially available products, added color pigments such as navy blue, carmine, and chromium oxide were separated and discoloration was observed.

The mica-titanium composite material, which is a product of the present invention, is completely stable against alkali, whereas all commercially available products were unstable and gradually faded in color. As is clear from the following test results, the mica-titanium composite material, which is the product of the present invention, has poor pigment properties in terms of stability.

(Effects of the invention) The mica-titanium composite material of the present invention has advantages such as excellent color tone such as brightness and chroma, and excellent safety, weather resistance, light resistance, chemical resistance, solvent resistance, and heat resistance. It is revolutionary in that it is useful as a pigment for paints, cosmetics, plastics, inks, paints, decorations, daily necessities, textile products, ceramics, etc., and as a colored burl glossy material, and as a conductive layer for recording paper. It has great industrial utility value, as it is expected to be used as a recording layer, a conductive material such as an antistatic material, and an electromagnetic wave shielding material.

[Brief explanation of drawings]

Figure 1 is a photograph (scanning electron microscope; 72,000x magnification) showing the crystal structure of the blue pearlescent material obtained in Example 1.
, FIG. 2 is its Xll11 diffraction pattern.

Claims (1)

[Claims] A mica-titanium composite material in which a mica surface is coated with titanium dioxide, and the titanium dioxide-coated mica surface is further coated with one or more metal particles selected from cobalt, nickel, and copper.