JP3351981B2 - High brilliant metallic pigment with excellent weather resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly brilliant metallic pigment to be mixed in a metallic paint for coating an automobile body, exterior building materials and the like.

[0002]

2. Description of the Related Art A paint film mixed with a metallic pigment shines upon reflection of incident light from the outside onto a scaly metallic pigment dispersed in the paint film, and the design is improved in combination with various colors of the paint film. It has an excellent and unique appearance. Utilizing this feature, it is used for painting the bodies of automobiles and two-wheel drive vehicles. Metallic pigments such as aluminum foil, copper foil, stainless steel foil, mica, and plate-like iron oxide have been used as the metallic pigment. However, none of the conventional pigments can be said to be metallic pigments having both weather resistance and glitter. For example, aluminum foil and copper foil exhibit considerable glitter as metal foil, but are inferior in glitter as compared to glass flakes.

[0003] The difference in brilliancy results from the surface condition of the substrate. Glass flakes have an extremely smooth surface because they are cooled and solidified from a liquid state. However, aluminum and copper foils are manufactured by machining such as ball mills and stamp mills, so that fine irregularities due to processing are produced. Remains. Mica, plate-like iron oxide, and the like exhibiting excellent weather resistance also have many fine irregularities on the surface as compared with glass flakes, and their glittering properties are considerably inferior. As a metallic pigment exhibiting excellent glitter, glass flakes subjected to electroless nickel plating or electroless silver plating are commercially available. Using the glass flakes obtained by electroless plating nickel or silver, metallic paints (JP-A-4-359957 and JP-A-5-17710) and retro-brilliant paints (JP-A-5-177710)
179174) and an adhesive tape excellent in sparkling effect (JP-A-5-320588) are manufactured.

[0004]

In order to achieve the required glitter by electroless plating of nickel or silver, it is necessary to use 50 or less.
Electroless plating is required to be relatively thick at 0 to 2,000 °, and the consumption of expensive elements such as nickel and silver increases. In addition, since electroless plating is employed, the characteristics of a plating layer generated according to a change in a plating bath composition, a temperature condition, and the like are apt to fluctuate, and strict control is required. Moreover,
Many processes are required for pretreatment, washing, filtration, waste liquid treatment, and the like, which causes an increase in manufacturing cost. Furthermore,
Another disadvantage is that silver is easily oxidized and easily discolored to black when reacted with sulfide. For this reason, weather resistance is insufficient for use as a metallic pigment for exterior building materials, as well as for vehicle bodies such as automobiles and two-wheel drive vehicles. However, recently, in order to impart designability and distinctiveness, development of a highly brilliant metallic pigment having excellent weather resistance for automobiles, two-wheel drive vehicles, and exterior building materials has been strongly desired. However, it has been difficult to produce a metallic pigment with improved weather resistance and brilliancy more than the current state by the conventional production technology. The present invention has been devised to solve such a problem.By forming a metal thin film on the surface of glass flakes by a sputtering method instead of electroless plating, compared to conventional metallic pigments. It is an object of the present invention to provide a highly brilliant metallic pigment which is remarkably excellent in weather resistance, brilliancy and quality stability at low cost.

[0005]

SUMMARY OF THE INVENTION The high brilliant metallic pigment of the present invention has an average particle diameter of 10 to achieve the object.
A metal thin film made of titanium or a titanium alloy having a thickness of 50 to 200 ° is formed by sputtering on a surface of a glass flake having a thickness of 300 μm and an average thickness of 1 to 20 μm via a compound layer composed of Ti—Si—O and Ti—Al—O. It is characterized by having been done. This highly brilliant metallic pigment can be blended with paints to form a coating film with a rich metallic feel, and also blended with resin plastics for plastic molded products to obtain molded products with similarly excellent surfaces. used.
Further, this metallic pigment is mixed with printing ink, and is applied to a reflective tape, a display material, a signboard, and the like.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The glass flakes used for the substrate are scaly particles having an average particle diameter of 10 to 300 μm (preferably 20 to 100 μm) and an average thickness of 1 to 20 μm (preferably 5 to 10 μm). Has a size. With glass flakes having an average particle size of less than 10 μm, it is difficult to orient in a certain direction in the coating film, and no glitter is exhibited. Conversely 300μ
When the average particle size exceeds m, fine metallic feeling cannot be obtained. Further, it is difficult to produce glass flakes having an average thickness of less than 1 μm. Glass flakes are not limited in their material, but include elemental glass, hydrogen-bonded glass, oxide glass, fluoride glass, chloride glass, sulfide glass, carbonate glass, nitrate glass, sulfate glass, etc. used. Considering price and performance, oxide glass such as silicate glass, alkali silicate glass, soda-lime glass, lead glass, barium glass, and borosilicate glass is preferable.

[0007] As the metal for coating the surface of the glass flake, titanium or a titanium alloy having excellent corrosion resistance is preferable. Coating with titanium or a titanium alloy is not possible by electroless plating, but can be easily applied to the surface of glass flakes by sputtering. As a titanium alloy, for example, 95% Ti-5%
Al, 95% Ti-5% Cr, 95% Ti-5% Fe,
95% Ti-5% V, 95% Ti-5% Mn, 92% T
i-4% Al-4% Mn, 92% Ti-5% Cr-3%
Al, 95.75% Ti-2.7% Cr-1.3% Fe
There are α phase alloys such as −0.25% O, β phase alloys, and α + β two phase alloys. These titanium alloys are used alone or in combination depending on the purpose.

[0008] As a method of coating glass flakes with titanium or a titanium alloy, ion plating, vacuum evaporation and the like can be considered. However, the powder sputtering method developed by the present inventors is most suitable for forming a stable coating layer without adversely affecting the properties of the glass flakes (base material) and the coating layer. Incidentally, when the temperature at the time of coating exceeds 600 ° C. as in the CVD method, the glass flakes themselves are softened, and the smoothness of the surface which affects the glitter decreases. In this type of powder sputtering method, a method of feeding powder to a rotating drum and sputtering powder particles fluidized by rotation of the rotating drum (Japanese Patent Application Laid-Open No. 153068/1990), repetition of falling powder (JP-A-62-250172).

In the powder sputtering, for example, an apparatus having a facility configuration shown in FIG. 1 is used. In this powder sputtering apparatus, a rotating drum 1 is supported by two rolls 2, and one of the rolls 2 is rotated by a motor 3. Inside the rotating drum 1, two sputtering sources 4 are arranged, and the charged glass flakes 5 are sputtered. Above the rotating drum 1, a heating coil 6
The decompression processing chamber 7 provided with
Is connected to the rotary drum 1 via a supply pipe 9 provided with a valve 8. The supply pipe 9 has a double pipe structure in which an Ar gas introduction pipe 10 is inserted inside a portion below the valve 8, and is inserted into the inside of the rotary drum 1 from a side surface, and a tip of the rotary drum 1 is provided. Extends to the bottom. A branch pipe 11 is attached to the supply pipe 9 below the valve 8, and the tip of the branch pipe 11 is connected to the fluid jet mill 12. The outlet side of the fluid jet mill 12 is connected to the upper part of the decompression processing chamber 7 via the circulation pipe 13. Valves 14 and 15 are inserted into the branch pipe 11 and the circulation pipe 13, and a solid-gas separation device 16 is connected to the circulation pipe 13.

The glass flakes 5 metal-coated by sputtering in the rotary drum 1 are sent from the branch pipe 11 and the circulation pipe 13 to the decompression processing chamber 7, and are repeatedly subjected to the sputtering process until a film having a predetermined thickness is formed. . The glass flakes 5 on which a film having a predetermined thickness is formed are collected by a solid-gas separator 16. When forming the titanium alloy layer by the powder sputtering method, a target prepared by a sintering method, a melting method, or the like is used. In the case of a target composed of a plurality of crystal phases, adjustment is made so as to be equal to the target average composition of the titanium alloy layer. Further, a target in which a metal to be alloyed is embedded in a titanium plate, which is a main component of a target titanium alloy layer, a target in which a plurality of single metals are combined, and the like are also used.

In general, it is said that the thicker the coating layer applied to the substrate, the larger the irregularities on the surface of the coating layer and the lower the glitter. For example, in electroless plating, it is said that the entire surface of the powder cannot be uniformly coated unless the film thickness is increased to 1,000 mm or more, but in the sputtering method, the entire surface is sufficiently coated even with a thin film of 200 mm or less. Is possible. Therefore, more excellent glitter is imparted to the flaky substrate. Moreover, since the consumption of titanium or a titanium alloy can be reduced, the production cost can also be reduced. The powder sputtering method forms a metal thin film on the surface of a glass flake by utilizing a phenomenon not seen in the conventional coating method as described below, whereby the weather resistance and brilliancy are remarkably excellent. A metallic pigment is obtained.

(1) In the sputtering method, a phenomenon in which metal atoms excited to a plasma state collide with the surface of a glass flake at a high speed is repeated. SiO ₂ and Al ₂ O constituting glass flakes by this collision energy
Oxide such as ₃ reacts with metallic titanium and Ti-Si
Compounds such as -O, Ti-Al-O are formed. As a result, a film having better adhesion than electroless plating is formed. (2) The compound layer formed at the interface serves as a starting point of nucleation for film formation during coating. In the powder sputtering method, many nucleation starting points are formed extremely finely and densely. Therefore, the surface of the glass flake can be uniformly coated with a small amount of titanium, and the formed coating layer also has a dense structure. Therefore, the obtained metallic pigment has excellent glitter.

On the other hand, in the electroless plating, a pretreatment for activating the surface of the glass flakes with Pd or the like is performed in advance. It is said that the portion to which Pd adheres becomes a nucleation point for film formation during electroless plating. The adhesion strength of Pd, which is a physical adsorption phenomenon, is significantly weaker than the sputtering method, and the adhesion density of Pd is considerably smaller than the collision density of metal atoms excited in a plasma state. for that reason,
It is presumed that the film formed by electroless plating tends to be coarse, and there is a limit in improving the glitter. After uniformly coating the surface of the glass flakes with titanium or a titanium alloy by the sputtering method, in order to improve the dispersibility of the paint and the adhesion with the resin, a coating treatment using an organic substance such as a fatty acid and various coupling agents are performed. The used surface treatment may be performed. Examples of the coupling agent include γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinylethoxysilane, γ-methacryloxypropyltrimethoxysilane. Methoxysilane, titanium-based coupling agents, zirconia-based coupling agents, aluminum-based coupling agents, and the like are used.

The amount of the metallic pigment coated with glass flakes with titanium or a titanium alloy is preferably adjusted in the range of 0.1 to 30 parts by weight with respect to 100 parts by weight of the vehicle component (solid content). .
If the amount of the metallic pigment is too small, a high-quality metallic feeling with depth cannot be obtained. The upper limit of the compounding amount is not particularly limited, and is appropriately determined within the range of usually up to 20% by weight, particularly preferably up to 5% by weight, depending on the type of resin, required physical properties of the molded article, and the like. The vehicle component is preferably a curable resin composition containing a base resin and a crosslinking agent as main components. Examples of the substrate resin include an acrylic resin having a crosslinkable functional group, a polyester resin, an alkyd resin, and the like, and a resin having as high a transparency as possible is used. As the cross-linking agent, a methylolated or alkyletherified melamine resin, a urea resin, a polyisocyanate compound, or the like is used. In addition, a self-curing resin, a thermosetting resin, or the like can be used, and a resin colored with a dye, a pigment, or the like can also be used. As the solvent, an organic solvent for paint, water, or the like is used.

[0015]

Example 1 Example 1: Using the powder sputtering apparatus of FIG.
Transparent glass flakes of soda-lime glass (average particle size: 1
(0 μm, average thickness: 1 μm) was coated with a 95% Ti-5% Al alloy to a thickness of 50 °. Two 95% Ti-5% Al alloy sputtering sources 4 were arranged on a rotating drum 1 having an inner diameter of 200 mm and an axial length of 200 mm. As the sputtering source 4, a magnetron type having a frequency of 13.56 MHz and an output of 1.5 KW was used. After 100 g of glass flakes 5 are charged and the pressure in the vacuum processing chamber 7 is reduced to 3.0 × 10 ⁻³ Pa, Ar gas is introduced from the Ar gas introduction pipe 10 at a flow rate of 15 cm ³ / min, and the glass flakes 5 are branched. The liquid was sucked and transferred to the decompression processing chamber 7 through the pipe 11, the fluid jet mill 12, and the circulation pipe 13. Then, in the decompression processing chamber 7, 200
C. for 30 minutes to dry and degas.

Next, after completely replacing the atmosphere of the rotary drum 1 with Ar gas, the glass flakes 5 in the vacuum processing chamber 7 are removed.
From the supply pipe 9 to the rotating drum 1,
While rotating at a speed of 5 rpm, 3.0 × 10 ^-1 Pa
Was sputtered from the sputtering source 4 under the reduced pressure atmosphere described above. After 10 minutes, the sputtering was stopped, the pressure in the decompression processing chamber 7 was reduced, and Ar gas was introduced from the Ar gas introduction pipe 10 to remove the glass flakes 5 from the fluid jet mill 12.
The glass flakes 5 that were agglomerated during sputtering were loosened to individual particles as much as possible. The glass flakes 5 returned to the decompression processing chamber 7 were covered with a titanium alloy having a thickness of 10 ° via a compound layer composed of Ti—Si—O and Ti—Al—O. By repeating this sputtering five times,
After growing the titanium alloy film up to 50 °, it was recovered from the solid-gas separator 16.

Examples 2 to 5: In the same manner as in Example 1, the surface of the glass flake was
95% Ti-5% Cr, 95% Ti-5% Fe, T through a compound layer composed of -Si-O and Ti-Al-O
Each alloy layer of i alone and 92% Ti-5% Cr-3% Al was formed. Table 1 shows the average particle size, average thickness, and thickness of the formed coating layer of the used glass flakes.

Comparative Example 1: Transparent glass flake (average particle size: 10 μm, average thickness:
Electroless plating was performed on the surface of 20 μm) so that a silver film of 200 ° was formed. 500 g of the transparent glass flake was put into 1 liter of an aqueous solution containing 30 g / l of stannous chloride and 30 g / l of hydrochloric acid, and the glass flake was sensitized by stirring at 60 ° C. for 20 minutes.
Wash thoroughly with deionized water and palladium chloride 1.5 g / l
And 1 g of an aqueous solution containing 15 g / l of hydrochloric acid,
Stirred at room temperature for 20 minutes. The activated glass flakes are thoroughly washed again with deionized water, and the thickness is reduced to 20 μm by the following procedure using a silver ammonia solution and a reducing solution.
Electroless silver plating of 0 ° was applied.

(1) Preparation of Silver Ammonia Solution 8 g of silver nitrate was added to and dissolved in 100 ml of deionized water, and 4 g of potassium hydroxide was added to 100 ml of deionized water and dissolved. The solution after mixing showed a tendency to gradually become brown. 80m ammonium hydroxide
1 / l was added and stirred until the solution became clear. (2) Preparation of Reducing Solution After dissolving 18 g of table sugar in 200 ml of deionized water, 4 ml of concentrated nitric acid was added, and the mixture was boiled for 30 minutes to convert table sugar to invert sugar, and the solution was cooled to room temperature. (3) Electroless silver plating 500 g of pretreated glass flakes were put into 225 ml of silver ammonia solution, and 150 ml of reducing solution was gradually added at a dropping rate of 25 drops / min while sufficiently stirring at room temperature. The glass flakes subjected to the electroless silver plating were sufficiently washed with water and dried.

A coated steel sheet was prepared as follows using the total of six types of pigments obtained. To 10 parts by weight of each pigment, 8 parts by weight of toluene was added and stirred, and the pigment was uniformly dispersed in toluene. Next, 60 parts by weight of a thermosetting acrylic resin varnish (Amaltex 448-O manufactured by Mitsui Toatsu Chemicals, Inc.) and a melamine resin varnish [Uban 20] were added to the dispersion.
N-60: 12 parts by weight of Mitsui Toatsu Chemical Co., Ltd.) and 15 parts by weight of a solvent (a mixed solvent of toluene 65% by weight and n-butanol 35% by weight) were added, and the mixture was stirred for 30 minutes with a disper to prepare a metallic paint. did. 0.8mm thick, 300mm wide, 500mm long
mm polished steel plate was used. The polished steel sheet is treated with zinc phosphate according to a conventional method, and then electrodeposited using a cationic electrodeposition paint (Power Top U-30 manufactured by Nippon Paint Co., Ltd.), and heated at 160 ° C. for 30 minutes to obtain a dry film thickness. A 20 μm undercoat film was formed. Then, it was applied using an intermediate coating paint (Olga P-2 Gray-manufactured by Nippon Paint Co., Ltd.), and heated at 140 ° C. for 30 minutes.
An intermediate coating film having a dry film thickness of 35 μm was formed.

The original coating plate on which the undercoat film and the intermediate coat film were formed was coated with the metallic paint prepared as described above. Prior to painting, paint thinner (Nippe 298 Nippon Paint Co., Ltd.) so that the viscosity at 20 ° C. becomes 15 seconds in a No. 4 Ford Cup test.
Diluted the metallic paint. Then, the viscosity-adjusted metallic coating was electrostatically spray-coated on the intermediate coating with a spray gun to form a 15 μm-thick metallic coating. Next, a clear paint (Super Rack 128M-1 manufactured by Nippon Paint Co., Ltd.) was applied by wet-on-wet, and heated at 140 ° C. for 30 minutes to make the total dried film thickness 140 μm. Thus, Examples 1 to 5
A coated steel sheet was produced for a total of six samples of Comparative Example 1 and Comparative Example 1. The metallic feeling and weather resistance of the obtained coated steel sheet were investigated. The metallic feeling is achieved by a digital gonio-gloss meter (UGV
-5K Suga Test Instruments Co., Ltd.), and evaluated at 60 ° mirror reflectance.

The weather resistance was investigated in a 1,000 hour QUV test. In the QUV test, after turning on the ultraviolet lamp at about 60 ° C. for 4 hours, non-lighting for about 4 hours with moisture or moisture condensation at about 50 ° C. is defined as one cycle.
Conditions that were repeated three times per hour were employed. In this test, the test panel will be exposed to simulated hot tropical daytime conditions followed by warm, humid nighttime conditions during which moisture or moisture condenses on the panel surface. While the panel is wet with condensed moisture, the panel is exposed to intense ultraviolet light according to the repetition of the ultraviolet lighting process. The coated steel sheet exposed to the QUV test was periodically removed from the tester, and the change in appearance was measured using a color difference meter and a digital variable-angle gloss meter. Then, for each test piece, the amount of change from before the test was determined as the color difference ΔE and the gloss retention%. As can be seen from Table 1 showing the above test results, the coated steel sheet produced by using the metallic pigment according to the present invention has a suppressed change in color tone and glossiness in comparison with Comparative Example 1. It can be seen that it has practically sufficient weather resistance and exhibits an extremely excellent metallic feeling.

[0023]

[0024]

As described above, the highly brilliant metallic pigment of the present invention is obtained by adding Ti-S
A thin film of titanium or a titanium alloy having excellent corrosion resistance is formed by a sputtering method via a compound layer composed of i-O and Ti-Al-O. Since it is a coating by the sputtering method, T
It is formed through a compound layer composed of i-Si-O and Ti-Al-O, and can cover the glass flake surface more uniformly and densely with a smaller film thickness than the conventional method, and consumes titanium and titanium alloy. A high quality metallic pigment with suppressed increase. When this metallic pigment is mixed with a paint and applied to a steel plate, a coated steel plate with excellent weather resistance and brilliancy is obtained, and it is used as a car body for automobiles, two-wheel drive vehicles, and exterior building materials with high design and distinctiveness. Is done. Further, it can be applied to reflective tapes, display materials, signboards and the like by being mixed with printing ink, and can be kneaded into various plastic molded products and used as an agent for preventing the generation of weld lines.

[Brief description of the drawings]

Fig. 1 Powder sputtering system for coating titanium or titanium alloy on glass flake surface

[Explanation of symbols]

1: rotating drum 2: roll 3: motor 4:
Sputtering source 5: Glass flake 6: Heating coil 7: Decompression chamber 8: Valve 9: Supply pipe 10: Ar gas introduction pipe 11: Branch pipe 12: Fluid jet mill 13: Circulation pipe 1
4, 15: valve 16: solid-gas separation device

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junji Saida 7-1, Takayashinmachi, Ichikawa-shi, Chiba Nisshin Steel Co., Ltd. Technical Research Institute (56) References JP-A-5-179174 (JP, A) JP-A-2-153068 (JP, A) JP-A-9-188830 (JP, A) JP-A-4-359937 (JP, A) JP-A-5-320588 (JP, A) JP-A-2-124981 ( JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09C 1/28 C09C 3/00 C09D 5/38

Claims (1)

(57) [Claims] 1. An average particle diameter of 10 to 300 μm and an average thickness of 1.
Ti-Si-O on the surface of glass flakes of ~ 20μm
And a high- brightness metallic pigment excellent in weather resistance, formed by sputtering a metal thin film of titanium or a titanium alloy having a thickness of 50 to 200 ° via a compound layer of Ti-Al-O .