JP4135063B2 - Metallic paint and painting method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a paint used for metallic coating, and more specifically, a metallic paint capable of realizing a metallic coating having an excellent appearance with a metallic appearance and good design, with good orientation of vapor deposited metal flakes. The present invention relates to a method for painting automobiles.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in metallic coating of automobile bodies, coating using vapor-deposited aluminum flakes having good light reflectivity as a bright material has been performed in order to develop a metallic appearance.
[0003]
[Problems to be solved by the invention]
However, in such a conventional metallic coating, even if it is intended to realize a metal-like design with a metallic paint using a bright material such as vapor-deposited aluminum flakes, it is possible to use only small objects such as small products and parts. It was not possible to achieve this, and it was practically impossible to achieve a coating with a large area and a short production tact, such as automatic painting on an automobile body.
[0004]
Further, the conventional metallic paint and painting method in an automobile body painting line is to paint a film thickness of about 15 μm in two stages using a metallic bell painting machine. In this case, the paint NV value (Non Volatile value; The nonvolatile solid content is about 20%. Even if a highly reflective vapor deposited aluminum flake or the like is used for such a conventional metallic paint, it cannot be said that the orientation in the resulting metallic coating structure is sufficient, and a metallic design is not obtained.
[0005]
The present invention has been made in view of the above-described problems of the prior art. The orientation of the glittering material in the coating structure is good, a metallic appearance can be realized, and a wide area can be coated in a short time. An object of the present invention is to provide a metallic paint capable of achieving excellent paint efficiency and an automobile paint method using the same.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have confirmed that the above problems can be solved by diluting the paint base at a predetermined dilution rate and blending a specific viscous resin. The headline and the present invention were completed.
[0007]
That is, the metallic paint of the present invention has a dilution ratio of 150 to 500% using a diluent comprising a high-boiling solvent and a low-boiling solvent for a metallic paint base containing a bright material, a non-volatile solid containing a resin, and a solvent. diluted at a ratio of, made by adding 5 to 10 parts by weight of the viscous resin containing a cellulose-based resin the resin per 100 parts by weight in the metallic paint base, the total resin content 100 parts by weight in the metallic paint Further, 6 to 20 parts by weight of a rheology control agent is added .
[0008]
The metallic paint of the present invention comprises a high-boiling solvent and a low-boiling solvent, which is a metallic paint base containing a bright solid and a resin, and containing a non-volatile solid content and a solvent contained in a total amount of 5 to 15%. It is diluted with a diluent at a rate of 150 to 500%, and 5 to 10 parts by weight of a viscous resin containing a fiber-based resin is added to 100 parts by weight of the resin in the metallic paint base. .
[0009]
In addition, the automobile coating method of the present invention is a coating method using a metallic paint as described above, and is characterized in that painting is performed using a bell type coating machine.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the metallic paint of the present invention will be described in detail. In the present specification, “%” represents mass percentage unless otherwise specified.
As described above, the metallic paint of the present invention is prepared by diluting the metallic paint base at a dilution ratio of 150 to 500% using a diluent comprising a high-boiling solvent and a low-boiling solvent, and further, the metallic paint base. 5 to 10 parts by weight of a viscous resin containing a fibrous resin is added to 100 parts by weight of the resin content.
[0011]
Here, the metallic paint base includes a bright material, a nonvolatile solid content such as a resin as a coating film forming element, and a solvent. Typically, the nonvolatile solid content is 20 to 40%, The solvent is contained at a ratio of 80 to 60%.
Such metallic paint bases contain additives such as pigments, plasticizers, curing agents, surface conditioners, anti-settling agents, adhesion-imparting agents, and anti-sagging agents as film-forming elements in addition to the above components. It can be obtained by placing an order with a paint manufacturer.
[0012]
The bright material is typically metal flakes formed by vapor deposition, but vapor-deposited aluminum flakes can be suitably used because of good reflectivity.
Examples of the resin that forms the coating film-forming element include acrylic-melamine resins, polyester-melamine resins, and urethane resins.
Examples of the solvent include aromatic hydrocarbons, alcohols, glycol ethers, and ester ketones.
Examples of the pigment include carbon black.
[0013]
The metallic paint of the present invention is obtained by diluting the paint base as described above with a diluent, and the dilution ratio is 150 to 500%.
Here, this dilution rate is defined as a dilution rate of 100% when the same amount (for example, 1 kg) of diluent is added to the mass of the coating base (for example, 1 kg) and diluted.
In the present invention, by adopting such a dilution rate, the viscosity of the coating particles (flying particles) to be applied is lowered, and the deformation of the coating particles on the surface of the object to be coated is compared with the case of the conventional metallic coating. It is possible to cause the metal foil such as aluminum flakes in the paint to be arranged almost parallel to the surface of the object. Such a phenomenon is conceptually shown in FIG.
If the dilution rate is less than 150%, the coating particles are not sufficiently deformed during coating. On the other hand, if it exceeds 500%, the discharge amount of the coating machine increases, and it becomes substantially difficult to apply in the coating line.
[0014]
Further, the viscous resin contained in the metallic paint of the present invention may be a resin that strongly develops viscosity as a low boiling point solvent such as thinner evaporates after coating. Specifically, a CAB resin (cellulose acetate) Butyrate resin) and high molecular weight fiber (cellulose) resins.
In this way, the viscosity of the viscous resin develops as the low-boiling component of the applied paint evaporates, so that the flow of the vapor deposited metal flakes arranged in parallel as described above is prevented, thereby making the appearance close to metal A coating having is obtained.
The amount of the viscous resin added is 5 to 10 parts by weight with respect to 100 parts by weight of the resin contained in the paint base. If the amount is less than 5 parts by weight, the desired viscosity cannot be exhibited sufficiently. If the amount exceeds 10 parts by weight, physical properties of the coating film such as chipping resistance are deteriorated.
[0015]
Moreover, it is preferable that the metallic coating material of this invention contains a non-volatile solid content in the ratio of 5-15% in total, ie, NV value is 5-15%.
This non-volatile solid is the whole of the metallic paint, and corresponds to the total of the one derived from the above-mentioned metallic paint base and the one derived from the viscous resin to be added.
If the NV value is less than 5%, the above dilution ratio becomes too large and the discharge amount may increase to cause the problem of the above line. If it exceeds 15%, the deformability of the paint particles becomes weak.
[0016]
As described above, the diluent is composed of a high-boiling solvent and a low-boiling solvent. In this specification, a solvent having a boiling point of 100 ° C. or higher is called a high-boiling solvent, and a solvent having a boiling point of less than 100 ° C. is called a low-boiling solvent. To do.
Specific examples of the high boiling point solvent include thinners mainly composed of 3-acetic acid-methoxy-butyl, 2-ethanol acetate, alkylbenzene, and the like. Specific examples of the low boiling point solvent include ethyl acetate, toluene, and the like. Can be mentioned.
[0017]
In the metallic paint of the present invention, this high boiling point solvent is preferably contained in the diluent in a proportion of 20 to 50%.
Such a diluent composition is suitable for evaporating the solvent after coating and developing the viscosity of a CAB resin or the like while ensuring the paint particle deformability at the time of coating.
If the high boiling point solvent is less than 20%, the paint particles are excessively evaporated during the flight, and the paint particles cannot be sufficiently deformed on the surface of the object to be coated. If it exceeds 50%, it will become too wet during coating, and as a result of the slow evaporation and viscosity development after coating, it will be difficult for the vapor deposited metal flakes that are glittering materials to be aligned in parallel to the surface of the coating, and the coating film after curing May not satisfy the standards (color, gloss, etc.).
[0018]
Furthermore, in the metallic paint of the present invention, it is preferable to add a rheology control agent, and the addition amount is desirably 6 to 20 parts by weight with respect to 100 parts by weight of the total resin content.
As such a rheology control agent, one having thixotropy and exhibiting viscosity when shearing force is not applied can be used.
Accordingly, in the present invention, it is useful for exerting a stronger action of suppressing the flow of aluminum after coating particle coating, and specifically, a microgel or the like can be used.
When the addition amount is less than 6 parts by weight, the viscosity developing action may be insufficient. When the addition amount exceeds 20 parts by weight, the viscosity development is too early, and the glitter material is difficult to align in parallel. (Taste, gloss, etc.) may not be satisfied.
[0019]
Next, the automobile coating method of the present invention will be described.
The automobile coating method of the present invention uses the metallic paint of the present invention as described above, and is a method of coating by discharging the metallic paint onto an object to be coated with a bell type coating machine.
Here, it is sufficient that the bell type coating machine is a conventionally known one, but the shaping air flow rate is preferably set to 400 to 800 Nl / min. It is possible to sufficiently impart the coating particle deformation energy at the time.
If the shaping air flow rate is less than 400 Nl / min, the deformation energy of the paint particles may be insufficient, and if it exceeds 800 Nl / min, it becomes difficult to cope with air supply on the coating machine side.
[0020]
【Example】
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.
[0021]
(Example)
Commercially available metallic base paint for automobile coating containing vapor-deposited aluminum flakes as a glittering material (manufactured by Nippon Oil & Fats SF Coating Co., Ltd .; non-volatile solid content 35.5%, of which acrylic-melamine-based resin 27.1%, solvent content A diluent containing 25% 3-acetic acid-methoxy-butyl thinner as a high boiling point solvent and 75% ethyl acetate / toluene thinner as a low boiling point solvent. Was diluted at a dilution rate of 200%. The NV value of the obtained diluted base paint was 13%.
Further, 7 parts by weight of the CAB resin is added to 100 parts by weight of the resin in the base paint, and 11 parts by weight of the RC agent (rheology control agent) is added to 100 parts by weight of the total resin. Got.
[0022]
(Comparative Example 1)
Except for the dilution rate of 100%, the same operation as in Example 1 was repeated to obtain a metallic paint of this example.
[0023]
(Comparative Example 2)
Except for adding 2 parts by weight of the CAB resin, the same operation as in Example 1 was repeated to obtain a metallic paint of this example.
[0024]
(Comparative Example 3)
Except that the high boiling point solvent in the diluent was changed to 10%, the same operation as in Example 1 was repeated to obtain a metallic paint of this example.
[0025]
[Performance evaluation]
Using the metallic paints of Examples and Comparative Examples 1 to 3, coating was performed under the following conditions.
・ Coating machine: ABB921 type, metallic bell-type coating machine, reciprocating painting ・ Coating conditions; discharge rate 130ml / min, bell rotation speed: 1500rpm
・ Shaping air flow rate: 500 Nl / min
・ Conveyor speed 2.0m / min
・ Gun distance; 230mm
・ Coating times: 4 times ・ Booth temperature and humidity: 30 ° C., 58% RH
・ Lightness of object to be coated; N = 6 on intermediate coating plate ・ Film thickness: Base coat 8μm, Clear coat 30μm
[0026]
As a result of the above performance evaluation, according to the metallic paint of the example, silver having a high orientation that could not be obtained by conventional metallic painting could be applied.
Moreover, the measurement result by the metallic feeling measuring machine (1) (IV meter) was 400 or more (scale over). On the other hand, the conventional silver is about 180-250. Furthermore, the measurement result by the metallic feeling measuring device (2) (X-Right) has a FI (Flop Index) value of 22.8, which is markedly improved as compared with about 10 to 15 of conventional silver. In addition, the metallic feeling visually was also excellent.
On the other hand, in the coating with the metallic paint of Comparative Example 1, the FI value of X-Right is 15.98, in Comparative Example 2, the FI value of X-Right is 19.32, and in Comparative Example 3, the FI value of X-Right is It was found to be 16.40, and the desired metal feeling could not be obtained.
[0027]
【The invention's effect】
As described above, according to the present invention, the coating base is diluted at a predetermined dilution ratio and a specific viscous resin is blended, so that the orientation of the deposited metal flakes in the coating structure is good. Thus, it is possible to provide a metallic paint capable of realizing a metallic appearance, painting a wide area in a short time, and achieving an excellent painting efficiency, and an automobile painting method using the same.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a state of flying paint particles on an object surface.

Claims (6)

A metallic paint base containing a bright material, a non-volatile solid containing a resin, and a solvent is diluted at a dilution ratio of 150 to 500% using a diluent composed of a high-boiling solvent and a low-boiling solvent. Viscosity resin containing 5 to 10 parts by weight of a resin containing fiber base resin is added to 100 parts by weight of resin in base, and further 6 to 20 parts by weight with respect to 100 parts by weight of total resin in metallic paint A metallic paint characterized by adding a rheology control agent . A metallic paint base containing a glittering material and a resin and containing a non-volatile solid content and a solvent contained in a ratio of 5 to 15% in total is diluted with a diluent consisting of a high-boiling solvent and a low-boiling solvent at a dilution ratio of 150 to A metallic paint characterized in that it is diluted at a rate of 500% and 5 to 10 parts by weight of a viscous resin containing a fiber-based resin is added to 100 parts by weight of the resin in the metallic paint base.   The metallic paint according to claim 1 or 2, wherein the high-boiling solvent is a solvent having a boiling point of 100 ° C or higher, and the high-boiling solvent is contained in the diluent in a proportion of 20 to 50%. A metallic paint comprising 6 to 20 parts by weight of a rheology control agent added to 100 parts by weight of the total resin content in the metallic paint according to claim 2 .   A coating method for automobiles, wherein the metallic coating material according to any one of claims 1 to 4 is used, and coating is performed by a bell type coating machine.   6. The automobile coating method according to claim 5, wherein the shaping air flow rate is 400 to 800 Nl / min.

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