JP2698514B2 - Water repellent powder coating and coating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-repellent powder coating excellent in water repellency, waterproofness, corrosion resistance, snow resistance, weatherability and lubricity, and a method of applying the same.

[0002]

2. Description of the Related Art Water repellency, waterproofness, corrosion resistance, snow resistance,
If a material with excellent weather resistance and lubricity is developed, the material can be applied to the draft surface of the ship to realize an energy-saving ship with reduced frictional resistance between water and the painted surface. A wide range of applications, such as difficult antennas, cables, and towers, as well as jigs for civil engineering machinery, are possible. Therefore, attempts have been made to develop a paint having the above-mentioned characteristics and a method of applying the same.

[0003]

However, the prior art paints and coating methods have the following drawbacks. First, there is a method of increasing water repellency as the contact angle approaches 180 degrees, and as a result, expecting waterproofness, anticorrosion, and snow prevention properties.However, this method is based on wet plating technology, so this method The treatment can be applied only to the object to which the wet plating treatment can be applied. In addition, solid Teflon and the like have insufficient water repellency, and it is difficult to ensure water repellency, waterproofness, corrosion resistance, snow resistance, weather resistance and lubricity that can withstand practical use. There has been a long-awaited need for new paints and coating methods.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a paint excellent in water repellency, waterproofness, corrosion resistance, snow resistance, weather resistance and lubricity, and its coating. It is to provide a method.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide 1 to 70% by volume of a fluorinated graphite powder having an unbound fluorine content of 3% by weight or less, a polyester resin powder, an epoxy resin powder, an acrylic resin powder and a urethane resin powder. A water-repellent powder coating comprising at least one or more resin powders or mixed resin powders among fluororesin powders; and This can be achieved by a water-repellent powder coating method characterized in that the coating is performed while the coating is kept at 130 ° C. or higher and 370 ° C. or lower in the coating. The application range of the paint and the coating method is wide, and it can be widely applied to, for example, outdoor facilities for telecommunications that require long-term reliability.

Further, the corrosion resistance can be further enhanced by adhering the polyester resin powder to the object to be coated before applying the above method. Further, after the polyester resin powder is adhered to the object to be coated, a non-bonded fluorine content of 3% by weight or less is adhered so that the area fraction of the surface becomes 1 to 70%. The effect of water repellency can be concentrated on the surface.

[0007]

The reason why the unbound fluorine content of the fluorinated graphite is set to 3% by weight or less in the above description is that when the unbound fluorine content is higher than this, the water repellency is reduced.
Further, the reason why the fraction of the graphite fluoride powder is set in the range of 1 to 70% is that the effect of water repellency does not appear below 1% by weight,
If it exceeds 70%, graphite fluoride is detached from the resin. In addition, the holding temperature is 130 ° C or more and 370 ° C
The reason for the lower limit is that the adhesion between the resin and the object to be coated is reduced at 130 ° C. or lower, and swelling or the like occurs on the coated surface at 370 ° C. or higher.

[0008]

EXAMPLES The paint and the method for coating the same according to the present invention will be specifically described below with reference to examples and comparative examples.

[0009]

EXAMPLE 1 A graphite fluoride powder having an unbound fluorine content of 0.1% by weight or less was mixed with a polyester resin powder so that the volume fraction became 30%, and SS 41 was heated to 330 ° C. in the mixed powder. After immersing the sample, it was cooled with water.

When a contact angle was measured by dropping a water drop on this sample, it showed a value of 172 °, indicating excellent water repellency.
Next, the sample was exposed to ultraviolet light for 600 hours using a sunshine weather meter (corresponding to outdoor exposure for 3 years), and the contact angle was measured to show a value of 167 °, indicating that it had excellent weather resistance. . Since this sample has water repellency, it is possible in principle to avoid corrosion, snow accretion, etc. caused by the adhesion of water. Further, when the surface of this sample was rubbed with No. 600 emery paper, it was found that the surface was not lubricated due to its slipperiness without causing fine irregularities on the surface.

[0011]

Example 2 After attaching a polyester resin powder to an SS 41 sample heated to 320 ° C., a graphite fluoride powder having an unbound fluorine content of 0.05% or less was added at the same temperature to a volume fraction of 0.05%.
A mixed powder mixed with the polyester resin powder so as to be 30% by volume was adhered.

When the contact angle was measured by dropping a water drop on this sample, it showed a value of 173 degrees, indicating excellent water repellency.
Then, the sample was measured with a sunshine weather meter for 600 minutes.
When the contact angle was measured after irradiation with ultraviolet rays for a period of time, the contact angle was 170 °, indicating that it had excellent weather resistance. Since this sample has water repellency, it is possible in principle to avoid corrosion, snow accretion, etc. caused by the adhesion of water. Further, when the surface of this sample was rubbed with No. 600 emery paper, it was revealed that the sample had lubricity without fine irregularities due to its slipperiness.

[0013]

Example 3 After attaching a polyester resin powder to an SS 41 sample heated to 320 ° C., a graphite fluoride powder having an unbonded fluorine content of 0.05% by weight or less and an area fraction of 30% at the same temperature. It adhered so that it might become.

When a contact angle was measured by dropping a water drop on this sample, it showed a value of 175 degrees, indicating excellent water repellency.
Next, this sample was irradiated with ultraviolet rays for 600 hours using a sunshine weather meter, and the contact angle was measured. The value was 171 °, indicating that the sample had excellent weather resistance. This sample can in principle avoid corrosion, snow accretion, and the like that occur through the attachment of water from a water-repellent place.

[0015]

Comparative Example 1 A polyester resin powder was adhered to an SS 41 sample heated to 320 ° C.

When a contact angle was measured by dropping a water drop on this sample, a value of 66 degrees was shown. Next, the sample was irradiated with ultraviolet rays for 600 hours using a sunshine weather meter, and the contact angle was measured. As a result, a value of 52 degrees was shown. As a result,
It can be seen that this sample is inferior in both water repellency and weather resistance to the sample of the present invention. In addition, the surface of this sample was
When rubbed with No. Emery Paper, it became clear that fine irregularities were generated on the surface and lubricity was poor as compared with the sample of the present invention.

[0017]

Comparative Example 2 A contact angle was measured by dropping a water drop on a Teflon sample and found to be 102 °. The contact angle of this sample was measured using a sunshine weather meter after irradiating it with ultraviolet light for 600 hours, and it was 95 °. Therefore, the water repellency of this sample is lower than that of the sample of the present invention.

Table 1 shows a comparison between the initial value of the contact angle and the value after irradiation with ultraviolet light, which were measured for the samples of the above Examples and Comparative Examples.

[0019]

[Table 1]

[0020]

As described above, the problem of the prior art can be solved by making the water repellent powder coating and the coating method thereof the coating and coating method of the present invention. A water-repellent powder coating excellent in water repellency, waterproofness, corrosion resistance, snow accretion resistance, weather resistance and lubricity and a method for coating the same can be provided.

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Claims (4)

(57) [Claims] 1 to 70% by volume of a fluorinated graphite powder having an unbound fluorine content of 3% by weight or less, and at least one of a polyester resin powder, an epoxy resin powder, an acrylic resin powder, a urethane resin powder and a fluorine resin powder. A water-repellent powder coating comprising at least one kind of resin powder or mixed resin powder. 2. A method for coating a water-repellent powder coating, comprising: coating the object to be coated in the water-repellent powder coating of claim 1 at a temperature of 130 ° C. or more and 370 ° C. or less. 3. An object to be coated is mixed with a polyester resin powder in an amount of 130.
A water-repellent coating characterized in that the resin is adhered by holding the resin at a temperature of not less than 130 ° C and not more than 370 ° C, and then the paint is held at a temperature of not less than 130 ° C and not more than 370 ° C. Powder coating method. 4. An object to be coated is mixed with a polyester resin powder in an amount of 130.degree.
After applying the resin while holding the resin at a temperature of not less than 370 ° C. and not more than 370 ° C., apply and coat a fluorinated graphite powder having an unbound fluorine content of 3% by weight or less so that the area fraction becomes 1 to 70%. A water-repellent powder coating method characterized by the following.