JPH11269432A - Microparticle-dispersed coating fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating fluid for forming a film on a substrate, which has improved dispersion stability and can form a color-unevenness-free, low-haze, uniform, high-quality, and light-transmitting coating film by dispersing functional microparticles in a vehicle under agitation and applying ultrasonic waves to the dispersion. SOLUTION: The vehicle used is exemplified by a polysilazane resin, an acrylic resin, an epoxy resin, a polyurethane resin, a fluororesin, a phenolic resin, or an alkyd resin. When the vehicle used is a polysilazane, it is possible to form a dispersion having a solid content of 45-99 wt.%. The functional microparticles used are exemplified by inorganic pigments such as ones of an oxide, compound oxide, or like type and organic pigments such as ones of an azo, fused polycyclic compound, phthalocyanine, or like type, or carbon black. The particle diameter of the microparticles in the dispersion is desirably 100 μm or below. It is suitable that the dispersion is free from an antisettling agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine particle dispersion for forming a film on a substrate surface, which uniformly disperses fine particles in a vehicle.

[0002]

2. Description of the Related Art Conventionally, in the fields of paints, printing inks, adhesives, etc., for example, a method in which a liquid in which a pigment is dispersed in a resin liquid is applied to a glass surface to obtain colored glass of various colors. Alternatively, various fine particles, such as those obtained by applying a mixture of glass powder and conductive metal powder to the surface of a ceramic substrate to obtain various circuit elements, etc. Dispersing is a popular activity.

However, due to the difference in specific gravity between the vehicle and the fine particles, the fine particles are always in a state of sedimentation, and the fine particles agglomerate during storage and precipitate at the bottom of the container, resulting in an uneven dispersion. Without stabilization, it may affect the color unevenness of the coating film, the difference in gloss, and the strength physical properties of the coating film, resulting in quality problems.

As one method for preventing the sedimentation of these fine particles, a method of adding an antisettling agent to a dispersion is widely adopted. For example, a paste which is swollen and finely dispersed in a nonpolar solvent is used. Surface activity, such as forming a loose flow curation structure with commonly used polyethylene oxide, fine particles, etc. in the form of particles, or improving the dispersion stability by thickening the adsorption layer by adsorbing on the fine particles with amphoteric properties Agent system.

However, in a vehicle such as a polysilazane solution, if a general-purpose alcohol-based or water-based anti-settling agent is used, the polysilazane and the anti-settling agent react to form a gel and cannot be used. There was a problem. When the functional fine particles are organic pigments, crystals grow in the non-aqueous solvent of the coating solution,
Because the particles are agglomerated and the coloring power is reduced,
Even if an anti-settling agent is used, if it is not applied within about 10 minutes after dispersion, the fine particles begin to agglomerate and do not stabilize, resulting in increased color unevenness, haze value (cloudiness value), etc., and transparency. Disadvantages such as loss of

[0006]

According to the present invention, the stability of a liquid is increased by applying ultrasonic waves to a dispersion liquid obtained by mixing and dispersing functional fine particles in a vehicle. Even when the dispersion is formed and baked after at least ten and several hours, there is no color unevenness, a small haze value, and a uniform fine particle dispersion for film formation on a substrate capable of forming a high-quality translucent coating film. A liquid is provided.

That is, according to the present invention, a dispersion in which functional fine particles are mixed and dispersed in a vehicle is coated on a light-transmitting substrate to form a film, and the dispersion is mixed and dispersed. The present invention relates to a fine particle-dispersed coating liquid that forms a film on the surface of a light-transmitting substrate after or while applying ultrasonic waves to the subsequent dispersion liquid.

Further, in a dispersion in which a polysilazane resin and an organic pigment are dispersed in a solution, the content of the polysilazane resin in the dispersion is preferably 45 to 99% by weight in terms of solid content. The particle diameter of the fine particles in the dispersion liquid is preferably 100 nm or less. further,
Suitably, the dispersion does not contain an antisettling agent.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below.
The dispersion is composed of a dispersion of functional fine particles in a vehicle. As the vehicle, polysilazane resin, acrylic resin, epoxy resin, polyurethane resin, fluorine resin, phenol resin, and the like are mainly used as organic materials.
Alkyd resin and the like can be used. In the case of the polysilazane resin, 45 to 99% by weight of the polysilazane resin as a solid content in the dispersion can be contained.
If the content is less than 10% by weight, the strength of the formed film becomes weak, which is not preferable.

As the functional fine particles, pigments such as inorganic pigments such as oxides (titanium oxide, iron oxide,
Benga), complex oxides, etc., and organic pigments such as azo pigments, condensed polycyclic pigments (quinacridone pigments, isoindolino pigments, isoindoline pigments, sulene pigments, perylene pigments,
Thioindigo, dioxazine, quinophthalone, diketopyrrolopyrrole), phthalocyanine, and other carbon blacks.

As a method of mixing and dispersing a mixed solution of a vehicle and fine particles, a ball mill method or a pebble mill method comprising a horizontally disposed cylindrical container and an appropriate amount of a ball or pebble dispersion medium therein, A sand grinder method of mixing and dispersing in a cylindrical container filled with sand particles with stirring, a roll mill method of mixing and dispersing between rolls, a high-speed impeller method, a high-speed stone mill method, and the like can be used. The ball mill method does not require pre-mixing of the vehicle and the fine particles, and it is a particularly preferable method because the solvent does not disappear due to evaporation or contamination from the outside.Therefore, mixing and grinding are performed until the fine particles are sufficiently dissociated. When the base material is a light-transmitting film such as glass and a light-transmitting film is formed, if the size of the fine particles under dissociation after mixing and dispersion is set to 100 nm or less, the formed film has a haze value ( (Turbidity) is as small as 2% or less, and the translucency is increased, which is more preferable.

The substrate used in the present invention can be used for a glass, a ceramic, a resin or the like having a light transmitting property, and the shape thereof is preferably a plate shape, but is not limited thereto. For example, as a glass substrate, a flow glass commonly used for architectural window glass, automobile window glass, and the like is used.
Glass (colorless or colored), its type or color tone, combination with other functional films, shape, etc. are not particularly limited. In addition to being able to be used as a single plate or a single plate, it can also be used as a double glazing or a laminated glass. The resin substrate is not particularly limited, such as an acrylic resin, a PVC resin, a polyurethane resin, a polycarbonate resin, and a polypropylene resin.

The ultrasonic wave applied to the dispersion is 10 to 50.
In the range of KHz, it is usually preferable to apply within 5 hours, especially 5 to 60 minutes, more preferably 10 to 30 minutes. Note that ultrasonic waves may be applied when forming a film on the substrate surface. The formed film is usually at room temperature to 400 ° C. (in the case of an organic pigment, 300 ° C.
(° C. or lower) to cure the film.

[0014]

According to the present invention, the vehicle and the functional fine particles are mixed and dispersed by a ball mill or the like to sufficiently dissociate the fine particles, and then the ultrasonic wave is applied to increase the stability of the liquid. A substrate with a light-transmitting coating film obtained by applying this dispersion after standing has no color unevenness, a small haze value, no unevenness due to aggregation of fine particles, uniform and high-quality light-transmitting properties. A substrate with a film is obtained. Although the reason why the application of the ultrasonic wave does not cause the aggregation of the fine particles is not clear, it is considered that the application of the ultrasonic wave increases the zeta potential and suppresses and stabilizes the aggregation of the fine particles.

Example 1 A solution of a polysilazane resin which is a compound having a silicon-nitrogen bond as a vehicle (manufactured by Tonen Co., Ltd., solid content of polysilazane resin: 20 wt%: xylene solvent: 80 wt%) 1
0.2 g of quinacridone (ci Pigment Red 122, manufactured by Dainichi Seika Kogyo Co., Ltd.) as an organic pigment is put into a ball mill, and mixed and dispersed for 12 hours. Next, the dispersion is placed in a dipping tank (size: 300 × 300 × 40 m).
m) and then transferred to ultrasonic (Shinmeidai Kogyo Co., Ltd.
26 KHz-output 600 W) is applied for 30 minutes. After leaving the dispersion in a dipping tank for 2 hours, a glass substrate (size: 250 × 300 × 3.
5 mm) is immersed in this bath, and the substrate is vertically pulled out of the bath at a pulling speed of 5 mm / s.
The coating was cured by drying in a drying oven maintained at 00 ° C. for 30 minutes.

The obtained functional film is a pink colored film having a film thickness of 1.5 μm, and has a haze value of 0.5% and a visible light transmittance of 77%, which is very transparent. A coated glass was obtained. This glass can be used as decorative glass for buildings or window glass of front doors for vehicles.

The thickness, haze value and visible light transmittance of the obtained glass substrate with a functional film were measured using the following apparatus. (Film thickness measurement) Measuring equipment: Model Dektak3, manufactured by Japan Vacuum Engineering Co., Ltd.
030 Sample size; 100 × 50 × 3.5 mm (cut to measurement size) (Haze value measurement) Measuring equipment: Model NDH20D manufactured by Nippon Denshoku Industries Co., Ltd. Sample size: 100 × 50 × 3.5 mm (Visible light transmission Ratio) Measuring instrument: Model U-4000, manufactured by Hitachi, Ltd. Sample size: 100 × 50 × 3.5 mm Example 2 Using the same vehicle and pigment as in Example 1, mixed and dispersed under the same conditions as in Example 1. I do. Next, the same ultrasonic wave is applied to the dispersion for 15 minutes in the same manner as in Example 1. After leaving the dispersion liquid in the dipping tank for 10 hours, the same glass substrate as in Example 1 was immersed in this tank, and then the substrate was vertically pulled up from the tank at a lifting speed of 5 mm / s.
Dry in a drying oven maintained at 200 ° C. for 60 minutes.

The obtained functional film was prepared in the same manner as in Example 1.
The film was a pink colored film having a thickness of 1.5 μm. The haze value of this film was 0.5%, and the visible light transmittance was 77%. As a result, a glass with a highly transparent colored film was obtained. This glass can be used as decorative glass for buildings or window glass of front doors for vehicles.

Example 3 A solution of a polysilazane resin as a vehicle (Tonen Co., Ltd.)
G of polysilazane resin (solid content: 20 wt%: xylene solvent: 80 wt%) and 6.3 g of a composite oxide as inorganic pigment (manufactured by Dainichi Seika Kogyo Co., Ltd., 9550 (black pigment)) are charged into a ball mill and mixed and dispersed for 12 hours. Next, the dispersion was placed in a dipping tank (size: 300 × 300 × 40 m).
m) and then transferred to ultrasonic (Shinmeidai Kogyo Co., Ltd.
26 KHz-output 600 W) is applied for 30 minutes. After the dispersion was left in a dipping tank for 1 hour, a glass substrate (size: 250 × 300 × 3.
5 mm) is immersed in this bath, and the substrate is vertically pulled out of the bath at a pulling speed of 6 mm / s.
The coating was cured by drying in a drying furnace maintained at 50 ° C. for 30 minutes.

The obtained functional film is a gray colored film having a thickness of 2.0 μm, and has a haze value of 0.6% and a visible light transmittance of 30%, which is very transparent. A coated glass was obtained. This glass can be used as decorative glass for buildings or window glass of rear doors for vehicles.

Example 4 Polysilazane resin solution as vehicle (Tonen Corp.)
G of polysilazane resin: 10 g of polysilazane resin: 80 g of xylene solvent) and 10 g of composite oxide as inorganic pigment (manufactured by Dainichi Seika Kogyo Co., Ltd., 9410 (blue pigment))
Into a ball mill and mixed and dispersed for 24 hours. Next, the dispersion is placed in a dipping tank (size: 300 × 300 × 4
0mm) and then ultrasonic (Shinmeidai Industry Co., Ltd.)
, 26 KHz-600 W output) for 30 minutes. After leaving the dispersion in a dipping tank for 1 hour, a glass substrate (size: 250 × 300
× 3.5 mm) was immersed in this tank, and then 8 mm / s
The substrate was vertically lifted from the bath at a lifting speed of, and then dried in a drying furnace maintained at 250 ° C. for 30 minutes to cure the coating.

The obtained functional film is a blue colored film having a thickness of 1.5 μm, and has a haze value of 0.4% and a visible light transmittance of 46%, which is very transparent. A coated glass was obtained. This glass can be used as decorative glass for buildings or window glass of rear doors for vehicles.

Comparative Example 1 Using the same vehicle and pigment as in Example 1, mixed and dispersed under the same conditions as in Example 1. Thereafter, a film is formed on the surface of the glass substrate under the same conditions as in Example 1 and dried after 30 minutes from the mixing and dispersion without applying ultrasonic waves.

The resulting film had a visible light transmittance of 77%, but had a very high haze value of 3.5, causing a turbidity in the glass, and was used for architectural and car front door windows. It could not be used as glass.

[0025]

According to the method of the present invention, even if the functional fine particles added to the vehicle are mixed and dispersed, the fine particles are not aggregated even when left for at least 10 hours or more, and are stabilized, uniform and haze-free. And a light-transmitting, high-quality film having a small particle size is obtained. Furthermore, the method can be applied to a liquid in which an anti-settling agent cannot be used.Also, even in a liquid using an anti-settling agent, the tendency of fine particles to settle down is extremely small, so that a simple method such as working efficiency can be achieved. It has the effect of obtaining a high quality transparent coating film.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09D 183/16 C09D 183/16

Claims (4)

[Claims] 1. A dispersion in which functional fine particles are mixed and dispersed in a vehicle, and the dispersion is coated and formed on a light-transmitting substrate to produce a substrate with a light-transmitting film. Ultrasonic waves are applied to the dispersion liquid after mixing and dispersing the fine particles in the vehicle to suppress aggregation of the fine particles and to stabilize the dispersion liquid. 2. A dispersion in which a polysilazane resin and an organic pigment are dispersed in a solution, wherein the content of the polysilazane resin in the dispersion is 45 to 99% by weight in solid content. Fine particle dispersion coating liquid. 3. The fine particle-dispersed coating liquid according to claim 1, wherein the particle diameter of the fine particles in the dispersion is 100 nm or less. 4. The fine particle-dispersed coating liquid according to claim 1, wherein the dispersion liquid does not contain an antisettling agent.