WO2017170966A1

WO2017170966A1 - Coating material for vehicle, production process therefor, and coating film formed from said coating material for vehicle

Info

Publication number: WO2017170966A1
Application number: PCT/JP2017/013472
Authority: WO
Inventors: 浩司寺本; 紀之中村; 修一郎谷本
Original assignee: マツダ株式会社
Priority date: 2016-03-31
Filing date: 2017-03-30
Publication date: 2017-10-05

Abstract

A coating material for vehicles which includes a coating-forming component, characterized by containing particles of a functional material dispersed in the coating-forming component, the particles of a functional material having an average primary-particle diameter of 1-30 nm.

Description

Vehicle paint, method for producing the same, and coating film formed using the vehicle paint

The present invention relates to a vehicle paint, a method for producing the same, and a coating film formed using the vehicle paint.

Conventionally, functional material particles having a size of several hundreds of nanometers have been added to impart functionality to a paint.

For example, Patent Document 1 discloses a method for producing an antibacterial paint containing titanium dioxide particles having a size smaller than 200 nm.

Special table 2014-524948 gazette

By the way, in a vehicle paint used as a raw material for a vehicle coating material, a solvent such as water is generally added to a raw material liquid containing particles of a functional material such as an ultraviolet absorber or a pigment having an average particle diameter of several hundreds of nanometers. Redispersion and refinement have been performed to obtain a vehicle paint containing functional particles having a smaller average particle size.

However, functional particles with a size of several hundreds of nanometers are actually aggregated into secondary particles of several μm in the above raw material liquid, and they aggregate even if they are further refined after dilution by adding a solvent such as water. It is difficult to re-disperse and refine uniformly from the state, it is difficult to obtain functional particles having a sufficiently small average particle size and a sufficiently narrow particle size distribution, and thus the transparency and color development of the paint. There was a problem that the property became low.

Therefore, an object of the present invention is to provide a coating material for a vehicle that includes particles of a functional material having a sufficiently small average particle diameter and is excellent in transparency, and a method for producing the same.

In order to achieve the above object, in the present invention, in the vehicle paint containing functional material particles, the average primary particle diameter of the functional material particles is within a predetermined range.

That is, the vehicle paint disclosed herein is a vehicle paint containing a paint-forming component, which includes functional material particles dispersed in the paint-forming component, and the average primary particles of the functional material particles. The diameter is 1 nm or more and 30 nm or less.

In this specification, the average primary particle diameter of the functional material particles is the dynamic particle size of the functional material particles contained in the first dispersion liquid or the second dispersion liquid in the vehicle paint manufacturing method described later. The average particle diameter D ₅₀ (nm) obtained by light scattering particle size distribution measurement.

The method disclosed herein is a method of manufacturing the above-described vehicle paint, and includes a preparation step of preparing a first dispersion containing particles of the functional material, and the first dispersion using a permeable membrane. And removing the impurities to obtain a second dispersion, and a mixing step of preparing the vehicle paint by mixing the second dispersion and the paint forming component. .

Also, the coating film disclosed herein can be suitably formed using the vehicle paint. In a preferred embodiment, the coating film may contain functional material particles having an average particle size of 1 nm to 100 μm.

The functional material particles tend to agglomerate with each other in the vehicle paint and the coating film to form aggregate particles having a large particle size. Accordingly, both the particles that do not form an aggregate and the aggregate particles can be included in the vehicle paint and the coating film. Therefore, in this specification, “the particles of functional material contained in the coating film” is a concept including particles that do not form such an aggregate and the aggregate particles. The “average particle diameter of the functional material particles contained in the coating film” is an average value of the particle diameters calculated from the electron microscope observation results of the functional material particles in the coating film.

As described above, according to the present invention, a highly transparent vehicle paint in which particles of a functional material having a small average particle diameter are uniformly dispersed, a manufacturing method thereof, and a paint formed using the vehicle paint are used. A membrane can be provided.

FIG. 1 is a flowchart for explaining a vehicle paint manufacturing method according to an embodiment. FIG. 2 is a cross-sectional view schematically showing an example of a laminated coating film of a vehicle body formed using the vehicle paint according to the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

<Vehicle paint>
The vehicle paint according to this embodiment is a paint that can be used as a material for a coating film formed on the exterior of a vehicle body such as an automobile, an aircraft, or a train.

The vehicle paint is prepared by mixing a film-forming component such as a resin, functional material particles, and other additives as required.

Examples of the paint forming component include resins such as acrylic resin, polyester resin, epoxy resin, and urethane resin. Furthermore, what has a sclerosing | hardenable functional group among the said resin, and hardening | curing agents, such as an amino resin which can react with these functional groups, and the blocked isocyanate resin as needed, can be included.

Examples of functional material particles include particles of pigments, deterioration inhibitors, strength securing materials, and the like.

The coating material may contain various additives well known by those skilled in the art, such as other surface conditioners, viscosity control agents, ultraviolet absorbers, and light stabilizers, as necessary.

<Method for manufacturing vehicle paint>
Below, the manufacturing method of the coating material for vehicles which concerns on this embodiment is demonstrated.

[Preparation process]
As shown in FIG. 1, a first dispersion containing functional material particles is prepared (S1). As a 1st dispersion liquid, a commercially available thing may be used and what contains the particle | grains of a desired functional material may be prepared.

The first dispersion containing functional material particles contains impurities such as acids, regardless of whether they are commercially available or prepared. When preparing a paint, it is necessary to remove these impurities and then mix with a film-forming component or the like.

[Removal process]
Then, impurities are removed from the first dispersion by osmotic pressure using the permeable membrane (S2). Specifically, the first dispersion liquid is allowed to flow through the channel formed of the permeable membrane as it is or with, for example, water or an organic solvent, and the water or organic solvent disposed outside the permeable membrane. Only impurities such as small molecules such as acids are permeated and dissolved to remove these impurities. Thus, a second dispersion from which impurities are removed is obtained.

The permeation membrane only needs to be a membrane capable of separating functional material particles and impurities. Specifically, for example, a polymer hollow fiber membrane, a ceramic membrane, or the like can be used.

[Mixing process]
And the said 2nd dispersion liquid, the above-mentioned coating material formation component, and various additives as needed are mixed and a coating material for vehicles is prepared (S3). The particles of the functional material are dispersed in the paint forming component as they are and / or in the form of aggregate particles.

Here, in the method for manufacturing a vehicle paint in the present embodiment, the concentration of the functional material particles in the obtained second dispersion is determined by removing impurities using the permeable membrane in the removal step S2. The purpose is to maintain the concentration at a level that does not cause agglomeration and to add a paint forming component, other additives, a solvent, and the like as it is to form a paint.

The concentration of the functional material particles contained in the second dispersion is appropriately changed depending on the type of the functional material, and is not particularly limited. For example, the concentration is 0.1 g / L or more and 10 g / L. L or less, preferably 0.2 g / L or more and 5 g / L or less.

When the concentration of the functional material particles in the second dispersion liquid is excessively high, the functional material particles are aggregated into secondary particles by intermolecular force. As the concentration of the particles of the functional material becomes higher, the secondary particles grow larger, even particles having an average particle diameter D ₅₀ of, for example, about 5 nm, agglomerated to an average particle diameter D ₅₀ of about 60nm Secondary particles. Then, when the coating material is made, for example, ultrasonic treatment or the like is performed to re-disperse / miniaturize the particles of the functional material, it is difficult to re-disperse / miniaturize the secondary particles. The particles are dispersed in the paint as large secondary particles. Thus, in the coating material in which the particles of the functional material having a substantially large particle diameter are dispersed, the transparency of the coating material and the coating film formed by the coating material is lowered, and the color development may be turbid.

In this respect, according to the present configuration, by keeping the average primary particle diameter of the functional material particles in the range, aggregation of the functional material particles is suppressed, and excessive growth of the secondary particles is suppressed. Then, by preparing the vehicle paint using the second dispersion described above, a vehicle paint in which the particles of the functional material having a small average particle diameter are uniformly dispersed can be obtained. Such a vehicle paint has a sufficiently small average particle diameter of the functional material particles, so that the effect of Rayleigh scattering is reduced and high transparency and vivid color can be provided. Then, when a coating film is formed on the surface of the coating layer using such a vehicle paint, the dispersibility of the functional material particles in the coating film is increased, and the coating film has a vivid color and high transparency. Secured.

The functional material particles are dispersed in the first dispersion and the second dispersion, and for the reasons described above, the average primary particle diameter is preferably 1 nm to 30 nm, more preferably 1 nm to 25 nm, particularly Preferably they are 2 nm or more and 20 nm or less.

Note that the form of the vehicle paint is not particularly limited, and may be any of a solvent type, a water dispersion type, and a water-soluble type. When the vehicle paint to be applied is a solvent-type, water-dispersed type or water-soluble type, its solid content concentration and viscosity are obtained by diluting with an organic solvent (non-aqueous solvent) and / or water (aqueous solvent). It can be adjusted appropriately.

The content of the functional material particles contained in the vehicle paint is not particularly limited, but from the viewpoint of providing a color without turbidity when a coating film is formed on the surface of the coating layer, the functional material particles 3 to 20% by mass concentration (mass of functional material particles contained in paint) / (sum of mass of functional material particles contained in paint and solids mass of paint forming component)) Is preferred. If it is less than 3% by mass, the function provided by the functional material may not be sufficiently provided to the coating film. If it exceeds 20% by mass, the viscosity of the paint increases, the paintability becomes insufficient, the surface smoothness cannot be obtained, and the coating film quality may be deteriorated. In addition, since the resin molecule bonds are reduced, physical properties such as scratch resistance and water penetration property may be deteriorated. A more preferred concentration is 5 to 15% by mass.

<Formation of coating film>
Examples of objects to be coated on which a coating film is formed using a vehicle paint include metals such as iron, steel, aluminum, tin, and zinc, alloys containing these, and molded products obtained by plating or vapor-depositing these metals. In addition, there can be mentioned moldings made of glass, plastics and foams, and specific examples include automobile bodies and automobile parts. The surface of the article to be coated may be provided with an undercoat film and an intermediate coat film.

The method for applying the vehicle paint is not particularly limited, and can be appropriately selected according to the type and form of the vehicle paint. Specifically, in the case of a solvent type, a water dispersion type or a water type, air spray coating And airless spray coating and electrostatic spray coating. The film thickness is not particularly limited, but is usually 2 to 200 μm, more preferably 2 to 50 μm in terms of dry film thickness.

The average particle size of the functional material particles contained in the coating film is preferably 1 nm or more and 100 μm or less, more preferably 2 nm or more and 100 nm or less, from the viewpoint of providing excellent transparency and vivid color development. Particularly preferably, it is 2 nm or more and 50 nm or less.

<Configuration example of laminated coating film>
FIG. 2 is an example of a laminated coating film 12 (coating film) provided on the surface of the automobile body 11 using the vehicle paint according to the present embodiment. The laminated coating film 12 is formed by laminating a colored base coating film 14, a metallic base coating film 15, and a transparent clear coating film 16 in this order. An electrodeposition coating film 13 is formed on the surface of the vehicle body 11 by cationic electrodeposition coating, and the laminated coating film 12 is provided on the electrodeposition coating film 13.

The vehicle paint according to the present embodiment includes, for example, as shown in FIG. 2, a colored base paint, a metallic base paint, a colored base paint film 14, a metallic base paint film 15 and a transparent clear paint film 16. It can be used as a clear paint.

When vehicle paints are used as these paints, curable paints are preferred from the viewpoint of the performance of the resulting coating film. These paints, that is, the colored base coating film 14, the metallic base coating film 15, and the transparent clear coating film 16 contain pigment particles 17 and deterioration inhibitor particles 19 as functional material particles. Further, the metallic base coating, and thus the metallic base coating film 15, contains a glittering material 18 as another additive.

The pigment particles 17 conceal the color of the surface of the object to be coated and give the laminated coating a color and transparency without turbidity. For example, carbon black, iron black, chromium black, copper chromate, titanium Examples thereof include iron-based black pigment iron oxide, pigment black, aniline black, and perylene. By making these pigments finer and more uniformly dispersed in the form of nanocrystals and particles, a more vivid color and transparency can be imparted to the coating film.

Also, the pigment particles 17 may have pigment nanocrystals or particles having a coating such as a silica coat into which hydrophilic groups or hydrophobic groups are introduced, for example. Thereby, the affinity of the pigment particles 17 with the aqueous solvent or non-aqueous solvent is improved, and the dispersibility of the pigment particles 17 in the paint is improved.

The deterioration preventing agent particles 19 are, for example, particles such as an ultraviolet absorber, and specifically include particles such as cerium oxide, zinc oxide, and iron oxide.

The glitter material 18 is an additive for imparting lightness to the laminated coating film. For example, flaky aluminum powder, alumina powder, bronze powder, copper powder, tin powder, zinc powder, iron phosphide, metal-coated mica powder Examples thereof include titanium dioxide coated mica powder. As the bright material 18, for example, from the viewpoint of efficiently obtaining a predetermined light reflectance and obtaining good design properties, for example, a flaky aluminum powder having a particle size of 8 μm to 30 μm and a thickness of 25 nm to 300 nm, that is, Examples include aluminum flakes.

Next, specific examples will be described.

Table 1 shows the configurations and evaluation results of Examples and Comparative Examples.

<Example 1>
[Preparation of second dispersion]
A commercially available sulfuric acid solution containing perylene nanocrystals was used as the first dispersion.

The first dispersion is introduced into a permeation apparatus equipped with a flow path formed using a permeable membrane (NGF cefilt UF, pore size 10 nm) while diluting with water, and concentrated after removing impurities such as sulfuric acid molecules. Thus, a second dispersion was obtained. The concentration of perylene nanocrystals in the second dispersion was 2 g / L.

[Preparation of vehicle paint]
A stainless steel container was charged with 65.6 parts by mass (solid content) of an acrylic resin made by Nippon Paint Co., Ltd., and 11.0 parts by mass of a second dispersion containing perylene nanocrystals was added and dispersed in terms of perylene. Next, 15.5 parts by mass (solid content) of Uban 128 (Butyled Melamine Resin, trade name, manufactured by Mitsui Chemicals, Inc.) was added and stirred with a desktop stirrer to prepare the vehicle paint shown in Table 1. This was adjusted to the coating viscosity.

[Preparation of objects to be coated]
On the zinc phosphate-treated dull steel plate, Powernics 110 (Cation Electrodeposition Paint Composition manufactured by Nippon Paint Co., Ltd.) is electrodeposited so that the dry film thickness is 20 μm, and cured by heating at 160 ° C. for 30 minutes. A film was formed. This was the object to be painted.

[Formation of coating film]
The vehicle paint was applied to the object to be coated with a metabell (rotary atomization electrostatic coating machine) so that the dry film thickness was 12 μm.

<Comparative Example 1>
In the removal step, a vehicle paint was prepared in the same manner as in Example 1 except that perylene nanocrystals were precipitated instead of removing impurities using a permeable membrane and the supernatant was removed to obtain perylene nanocrystals. A coating film was formed.

<Example 2>
As shown in Table 1, and the average particle diameter D ₅₀ of Periren'nano crystals in the first dispersion are different, permeable membranes (NGK Co. Sefiruto NF, pore size 1 nm) except for using, as in Example 1 A vehicle paint was prepared and a coating film was formed.

<Comparative example 2>
As shown in Table 1, except that the average particle diameter D ₅₀ of Periren'nano crystals in the first dispersion are different, the coating vehicle was prepared in the same manner as in Example 1 to form a coating film.

<Example 3>
Using a commercially available sulfuric acid solution of iron oxide particles as the first dispersion, the impurities were removed by a permeation apparatus using a permeable membrane (Sefilt NF manufactured by NGK, pore size 1 nm) in the same manner as in the perylene nanocrystals of Example 1 and concentrated Thus, a second dispersion was obtained. At this time, the concentration of the iron oxide particles in the second dispersion was 0.5 g / L.

[Preparation of paint]
An acrylic resin 65.6 parts by mass (solid content) manufactured by Nippon Paint Co., Ltd. was placed in a stainless steel container, and 11.0 parts by mass of the second dispersion containing iron oxide particles was added thereto and dispersed in terms of iron oxide. Subsequently, Uban 128 (Butylated melamine resin, trade name, manufactured by Mitsui Chemicals, Inc.) was added to 15.5 parts by mass (solid content), and the mixture was stirred with a desktop stirrer to prepare the paint shown in Table 1. This was adjusted to the coating viscosity.

[Preparation of objects to be coated]
A coated layer was prepared in the same manner as in Example 1.

[Formation of coating film]
The coating material was coated on the object to be coated with a metabell (rotary atomization electrostatic coating machine) so that the dry film thickness was 12 μm.

<Comparative Example 3>
In the removal step, the paint for vehicles is prepared in the same manner as in Example 2 except that the iron oxide particles are precipitated instead of removing the impurities using the permeable membrane and the supernatant liquid is removed to obtain the second dispersion. A coating film was formed.

<Physical property evaluation>
[Average particle size of functional material particles]
The average particle diameter D ₅₀ of the functional material particles contained in the first dispersions of Examples 1 to 3 and Comparative Examples 1 to 3 was evaluated by particle size distribution measurement using a dynamic light scattering method.

Also, the average particle diameter of the functional material particles contained in the coating films of Examples 1 to 3 and Comparative Examples 1 to 3 was evaluated by observation with a transmission electron microscope (TEM, manufactured by JEOL). The evaluation is an average value of particle diameters of about 50 particles.

[Measurement of paint haze]
In order to evaluate the transparency of each of the paints of Examples 1 to 3 and Comparative Examples 1 to 3, haze measurement was performed. For haze measurement, a haze computer HGM-3D manufactured by Suga Test Instruments Co., Ltd. was used. In addition, each coating material used for the measurement in the state with which it filled with the commercially available transparent sample tube, and calculated | required haze on the basis of the measured value of the empty sample tube.

<Discussion>
As shown in Table 1, in the first dispersion liquid in Example 1 and Comparative Example 1 and Examples 3 and Comparative Example 3, respectively 15nm and 7nm average particle diameter D _50, also the first dispersion of Example 2 in, the average particle diameter D ₅₀ of 2 nm, the particles of the functional material has a sufficiently small particles. In the first dispersion of Comparative Example 2, the average particle diameter D ₅₀ is 40 nm, the particles of the functional material has a larger particle.

Next, when the average particle diameter of the coating film was compared, in Examples 1, 2 and 3, it was 27 nm, 7 nm and 20 nm, respectively, and it was found that about 2 to 3 particles were aggregated. On the other hand, in Comparative Examples 1 and 3, it was 55 nm and 62 nm, respectively, and it was found that about 4 to 9 particles were aggregated. In Comparative Example 2, the average particle diameter D ₅₀ of the coating film is 85 nm, and it is considered that about 2 to 3 particles are aggregated as in Examples 1, 2, and 3. Since the size of the particles in the liquid was large, it was found that the average particle size exceeded 50 nm.

When the hazes of the paints of Examples 1 to 3 and Comparative Examples 1 to 3 were measured, each of Examples 1, 2 and 3 showed excellent transparency at less than 0.1, whereas Comparative Examples 1 and 2 showed excellent transparency. , 3, it was found that the transparency was inferior in 8, 6 and 11.

As described above, from the results of Examples 1 to 3 and Comparative Examples 1 and 3, excessive aggregation of functional material particles in the coating film is suppressed by removing impurities from the first dispersion using a permeable membrane. In addition, it has been found that it is possible to provide a coating material that provides a coating film having excellent transparency and color development without cloudiness. Further, from the results of Comparative Example 2, even when using a permeable membrane, the average particle diameter D ₅₀ of the particles of the functional material in the first dispersion liquid is increased to 40 nm, the functional material in the coating film It has been found that the size of the particles increases, so that the transparency decreases.

The present invention provides a highly transparent vehicle paint in which particles of a functional material having a small average particle size are uniformly dispersed in a solution, a method for producing the same, and a vehicle coating film formed using the vehicle paint. Can be very useful.

17 Pigment particles (particles of functional materials)
19 Deterioration inhibitor particles (functional material particles)

Claims

A vehicle paint containing a paint forming component,
Containing particles of functional material dispersed in the paint-forming component,
An average primary particle size of the functional material particles is 1 nm or more and 30 nm or less.
A method for producing the vehicle paint according to claim 1, comprising:
Preparing a first dispersion containing particles of the functional material;
A removal step of removing impurities from the first dispersion using a permeable membrane to obtain a second dispersion;
A method for producing a vehicle paint, comprising: a mixing step of preparing the vehicle paint by mixing the second dispersion and the paint-forming component.
A coating film formed using the vehicle paint according to claim 1.
The coating film according to claim 3,
A coating film comprising particles of a functional material having an average particle diameter of 1 nm to 100 μm.