JP3370459B2 - Method for producing water-repellent coating - 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 material and prevention of sticking to ice and snow.
Manufacturing method of water-repellent coatings used for chemicals and antifouling materials
You. [0002] 2. Description of the Related Art As a water-repellent coating, silicon
Coatings of fluorine-based or fluorine-based resin compounds are often used,
As a method for producing an aqueous coating, generally, polytetrafluoroethylene is used.
Fluorocarbon fine powder such as fluoroethylene
And apply the paint suspended in a
A method of performing a baking process for about one hour is often used.
(JP-A-62-186133). However, fluorocarbon fine powders
In the method of baking, the surface is flattened,
Aqueous equivalent to polytetrafluoroethylene plate
(The contact angle with water is about 110 °) is the limit.
Water repellency such that the lotus leaf repels water (12 in contact angle with water)
0 ° or more), and baking at a high temperature of about 400 ° C
It is applicable to wood, plastic, etc.
There was a drawback that it was impossible. [0004] In addition, the provision of fine irregularities on the surface
A water-repellent coating that expresses water repellency has also been proposed.
As a method of forming a water-repellent coating, the substrate surface is
A convex body was formed by roughening by etching etc.
Then, a method of forming a layer of a fluorine-based compound on the surface of the convex body
Method (Japanese Patent Application Laid-Open No. 4-343774), in a water-repellent resin.
Composition of silica and inorganic fine particles such as silica mixed with organic fine particles
Coating a product on a substrate to form a water-repellent coating
244679) and the like. However, in these methods,
The resulting water-repellent coating with irregularities on the lotus leaves
Near or similar water repellency, but roughened
Pre-treatment is required, or if powder is dispersed in the resin
The unevenness of the powder.
Variations in water repellency may occur, and resin may be applied on the powder.
Since the layer is covered, there are drawbacks such as the
Was. [0006] SUMMARY OF THE INVENTION The present invention solves the above problems.
It has been made in view of the above, and its purpose is suitable for various substrates.
A method for producing a coating that has stable and water-repellent performance
To provide. [0007] Means for Solving the Problems The production of the water-repellent coating of the present invention.
The fabrication method is based on (a) a base with a contact angle with water of 90 ° or more.
Plasma treatment of fine particles of wood, (b) tree
Forming a resin coating on the substrate by applying a fat to the substrate,
(C) The resin coating film obtained in step (b) is not cured
Or in a semi-cured state, obtained by step (a)
The plasma-treated microparticles are applied to the resin coating film.
After hardening of the film, the fine particles are not less than 20% of the resin coating surface area.
Attaching to be exposed in the upper region, and
(D) fine particle-adhered resin obtained in step (c)
A step of curing the coating film and fixing the fine particles to the resin coating film
It consists of about. [0008] The fine particles used in the present invention are in contact with water.
Fine particles made of a base material having an angle of 90 ° or more. A substrate having a contact angle with water of at least 90 °
Examples include polyethylene, polypropylene,
Graphite, fluorine-containing resin, organopolysiloxane, etc.
No. As the above-mentioned fluorine-containing resin, for example,
Fluoroethylene, hexafluoropropylene, perf
Fluorovinyl ether (perfluoromethyl ether
Etc.), perfluoroallyl ether, perfluoropro
Fluorine-containing polymerizable compounds such as pyrene and vinylidene fluoride
Homopolymer of monomer (polytetrafluoroethylene,
Polyvinylidene fluoride), their copolymers
(Vinylidene fluoride-tetrafluoroethylene-
Perfluoropropylene copolymer, vinylidenefluor
Id-hexafluoropropylene-tetrafluoroethyl
And copolymers of the above-mentioned fluorine-containing polymerizable monomers.
For example, fluorine-free heavy such as ethylene or propylene
And a copolymer with a compatible monomer. When the contact angle between the base material and water is reduced,
The force to enlarge the wet surface is greater than the water repellency
Therefore, even if it becomes uneven, the water repellency does not improve,
The contact angle with water is preferably 90 ° or more.
It's like water can't get in with irregularities and water drops float
It becomes a state and expresses water repellency such that water droplets roll on the surface
For this purpose, the angle is more preferably 95 ° or more. The above fine particles may be used alone,
More than one species may be used in combination. The fine particles have at least a surface in contact with water.
Any fine particles made of a base material having an antenna of 90 ° or more may be used.
For example, a substrate having the above-described properties is formed around a core material.
It may be provided. The average particle size of the fine particles becomes concave as the size becomes smaller.
The effect of the convex shape decreases and the contact angle decreases,
Then, the water repellency against fine water drops decreases, so 1 nm
１1 mm is preferred. In the present invention, the resin used for forming a resin coating film is used.
As the resin to be used, for example, a solvent drying type, a thermosetting type,
Resins, drying oils, and the like. When curing the above resin, if necessary
A polymerization initiator is added. In addition,
Besides, solvents, pigments, thixotropic agents, fillers, ultraviolet absorbers,
Antioxidants, polymerization inhibitors, surface modifiers, defoamers, curing aids
Various additives such as agents may be used. Hereinafter, the method for producing a water-repellent coating of the present invention will be described.
It will be explained according to the procedure. First, in step (a), water and
Particles consisting of a substrate with a contact angle of 90 ° or more
By subjecting the surface of the fine particles to a wet treatment,
Improve. As the gas used for the plasma processing,
For example, nitrogen; ammonia;
Gas, oxygen, ozone, water vapor, carbon monoxide,
Oxygen-containing gases such as carbon oxides, nitric oxide and nitrogen dioxide;
Rare gases such as helium, argon, neon, xenon;
Halogen gas such as nitrogen, chlorine, iodine, etc .;
On the other hand, carbon tetrafluoride (CF_Four),
Carbon hexafluoride (C_TwoF ₆), Propylene hexafluoride (C_Three
F₆), Etc.
I can do it. As the excitation means, for example, a DC voltage is applied.
Plasma decomposition by applying high frequency voltage
Plasma decomposition method using microwave discharge
How to decompose, plasm by electron cyclotron resonance
Thermal decomposition method, thermal decomposition method using hot filament
Method, etc., but DC voltage application or
Is preferable to apply high frequency voltage to decompose plasma
No. When the processing pressure during the plasma processing decreases,
Expensive vacuum chambers and evacuation equipment are required,
Becomes thermal plasma, and finally changes to arc discharge
1 × 10^-FourWithin 100 Torr
Is appropriately determined by the excitation means. Direct as excitation means
When using the flowing voltage application method or the high-frequency voltage application method, 1
× 10^-2A range of １００100 Torr is preferred. The input power required for the plasma processing depends on the electrode surface.
Depending on the product and shape, the lower the density, the lower the plasma density
Processing time and inefficiency.
Damage the particles to be processed, so
W is preferred. The electrode structure is parallel plate type, coaxial cylindrical type, curved
In the case of a flat plate facing surface or a parallel surface facing hyperboloid, capacitive coupling type
The voltage is applied in the formula. In the case of applying a high-frequency voltage,
It is possible to apply inductive form using external electrodes.
You. The distance between the electrodes is the processing pressure, the particle size of the fine particles.
Etc., but the plasma density increases as the length increases.
Can reduce fine particles and require high power, and can process fine particles.
It is better to keep it as short as possible. In the plasma treatment according to the present invention, fine particles
There is no need to heat or cool the
Minutes. The time required for the plasma treatment depends on the size of the fine particles.
It is determined as appropriate depending on the diameter, input power, etc.
If it is difficult, it is necessary to extend the plasma time.
The higher the force, the shorter the plasma time. Typically
Indicates that the processing time is shorter,
Becomes insufficient, and even if it becomes longer than necessary,
Since no further improvement can be expected, it takes about 1 to 60 minutes. At the time of plasma treatment, the entire surface of the fine particles is
Performing with stirring particles for uniform treatment across
Is preferred. As for this stirring method, fine particles are sealed
To mix fine particles by vibration
These methods, the particle size of the fine particles,
It is appropriately determined according to the processing amount and the like. The fine particles subjected to the plasma treatment react with the resin.
The wettability improves, and the resin hardens after adhering to the resin,
The adhesion between the fine particles and the resin is improved. Prevent particles
Since the plasma treatment is a treatment of the very surface layer of fine particles,
The exposed plasma-treated surface layer spreads inside the fine particles over time.
The wettability of the fine particle surface to the resin
To decline. Therefore, the plasma-treated fine particles will be described later.
Is as short as possible until use in step (c)
Is good. If this time is too long,
It is good to keep the fine particles frozen. In the step (b), a resin is applied to the substrate and
This is a step of forming a resin coating film thereon. As the above substrate
Is not particularly limited, for example, plastic
Plates and films, wood plywood, metal plates, etc. are used,
In addition, molded products such as fiber reinforced plastic (FRP)
Good. As a method of applying the resin to the base,
An appropriate method is selected depending on the resin to be used and the purpose.
Generally, for example, brush coating, spray coating, bar coating
Coating method, doctor blade method, roll coating method,
Ping method can be used. When the film thickness of the resin coating film becomes smaller,
In step (c), the fine particles are not sufficiently adhered, and the water repellency is improved.
Of the average particle size of the fine particles to be used.
It is preferably at least one third. Step (c) is obtained by step (b)
Process in the uncured or semi-cured resin coating
The plasma-treated fine particles obtained in (a) are
This is a step of attaching to a resin coating film. Attach fine particles
If the coating is cured before, fine particles can be fixed to the coating.
In the second step, the coating film is in an uncured or semi-cured state
Do with. The method for attaching the fine particles is particularly limited.
Although it is not specified, for example, fine particles are directly
Spray the tree, place it in a container such as a pallet
Place the substrate coated with grease so that the coating surface is in contact with the fine particles.
Immersion of the coating surface in fine particles, etc.
Contact the uncured or semi-cured coating film with fine particles
You only have to wear it. In addition, after attaching fine particles
The surface may be lightly pressed. The degree to which the fine particles adhere to the resin coating film
Is that, after the resin coating is cured, the fine particles are coated on the surface of the resin coating.
Attach so that it is exposed in an area of 20% or more of the product.
The reason is that the area over which the fine particles cover the resin coating film is small.
When it disappears, the water contact angle on the coating film surface becomes small and the water repellency is low
Therefore, the area where the fine particles cover the resin coating film is 20
% And more, so that water droplets roll on the surface
70% or more is recommended to ensure stable water repellency
It is more preferable. The fine particles cover the resin coating
For example, take an electron micrograph of the coating surface
Image processing to determine the percentage of surface area where the fine particles are exposed
Can be Step (d) is obtained by step (c).
In addition, the resin film coated with the fine particles is cured so that the fine particles are
This is the step of fixing to the coating film. Hardening method is the used tree
An appropriate method is selected according to the fat. After completion of the curing, if necessary, the film is fixed to the coating film.
Remove excess fines that were not applied. Excessive fine particles not fixed to the coating film are removed.
There is no particular limitation on the method of removing
For example, a method of removing by air spray can be used.
You. In addition, the magnitude of the tackiness of the coating film in the uncured or semi-cured state
For excessive resin, remove excess particles before curing the coating
And then the resin may be cured. Excess removed
By collecting and reusing fine particles of
The amount of fine particles can be minimized. After the curing is completed, the film is left to stand,
Restores the water repellency of the particle surface. Plas against fine particles
Since the surface treatment is a treatment for the very surface layer of fine particles,
The plasma-treated surface layer diffuses into the fine particles over time.
Therefore, the surface of the fine particles recovers the original water repellency over time
I do. At this time, after 5 days, the water repellency can be fully restored.
It is desirable to leave it on, and the water repellency can be restored in a short time.
If you want to keep it, it is better to store it at a temperature higher than room temperature.
Storage temperature is within the range that does not affect the substrate or coating
Is optional. As described above, it has high water repellency and
First, it is possible to obtain a water-repellent coating with improved adhesion of fine particles.
it can. [0039] [Function] The plasma-treated fine particles wet the resin.
When the resin hardens after adhering to the resin,
The adhesion between the child and the resin is improved. Plas against fine particles
Since the surface treatment is a treatment for the very surface layer of fine particles,
The plasma-treated surface layer diffuses into the fine particles over time.
Therefore, the surface of the fine particles recovers the original water repellency over time
I do. On the other hand, the plasma processing unit for fine particles in contact with the resin
The minute is adhered to the resin, so even if time passes
Adhesion is maintained without diffusion to the surface. in this way
Improves the adhesion between the water-repellent fine particles and the resin.
This improves the water repellency of the coating surface and improves the durability of the coating
I do. [0040] DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. Less than
“Parts” means “parts by weight”. (Example 1) From a substrate having a contact angle with water of 90 ° or more
Fine particles (fluorinated graphite, manufactured by Central Glass Co., Ltd., trade name
“Cefbon CMA”, average particle size 2 μm)
30 g in a 0 ml flask,
After exhausting to Torr, 0.11 Torr in an oxygen atmosphere,
With an input power of 40 W, a powder plasma processing device (Samcoin
According to the model PT-500 (Tarnation), 1
Apply a high frequency of 3.56 MHz and press for 40 minutes at room temperature.
Razuma treated. Unsaturated polyester on an aluminum plate
Resin (Mitsui Toatsu Chemical Co., Ltd., product name "ESTER V262
-G ") 55 parts by weight of methyl as a polymerization initiator in 100 parts
Ethyl ketone peroxide-dimethyl phthalate solution
1 part, 6% by weight cobalt naphthenate solution as curing aid
Spray-coated resin with 0.1 part added
did. This was filled with the above-mentioned plasma-treated fine particles.
Particles adhere to the surface by immersion in a container
After that, excess fine particles are removed by air spray and
After curing the coating by heating for 1 hour at
After standing for a day, a water-repellent coating was obtained. (Example 2) When the contact angle with water is 90 ° or more
Fine particles made of a certain substrate (Sumitomo 3M, product name
"THV200P", vinylidene fluoride-tetra
Fluoroethylene-perfluoropropylene copolymer,
The average particle size is 280 μm) instead of the oxygen atmosphere.
The procedure was the same as in Example 1 except that the
Zuma processed. On wood plywood, polyfunctional acrylate resin
(Manufactured by Nippon Kayaku Co., Ltd., trade name "Kayarad DPCA-30,
Caprolactone modified dipentaerythritol hexaac
Photoreaction initiator (Ciba-Geigy)
Product name "IRGACURE I-184", 1-Hydro
2 parts of xycyclohexyl phenyl ketone), curing aid
(Manufactured by Nippon Kayaku Co., Ltd., product name "Kayacure EPA", p
0.7 parts of dimethylaminobenzoate) were added.
The resin was applied using a bar coater. 50 ℃
After drying with hot air for 10 minutes,
Spray fine particles that have been treated and immediately remove excess particles by air.
-Removed by spraying. This is a high-pressure mercury lamp
2000 mJ / cm^TwoUV hard to be
And left in an oven at 80 ° C for 24 hours,
A membrane was obtained. (Example 3) When the contact angle with water is 90 ° or more
Fine particles made of a certain base material (trade name, manufactured by Daikin Industries, Ltd.)
"Lubron L-2", polytetrafluoroethylene,
The average particle size is 5 μm)
Make sure that it is kept in a gas atmosphere of carbon tetrafluoride at a volume ratio of 4: 1.
Other than the above, plasma treatment was performed in the same manner as in Example 1. Solvent drying mold coating on acrylic resin plate
(Made by Dainippon Color Materials Co., Ltd., product name "Novafusso PF-25
0 ", clear fluoro resin coating <base resin: vinylide
Fluoride-tetrafluoroethylene-perfluoro
Ropropylene copolymer>) using a doctor blade
And applied. The above-mentioned plasma-treated fine particles
And then dried at room temperature for 5 hours to cure the coating.
Was. After curing, remove excess particles by air spray
And left at room temperature for 7 days to form a water-repellent coating.
Obtained. (Example 4) In Example 1, the contact with water
Poly fine particles consisting of a base material with an antennae of 90 ° or more
Fine particles made of ethylene (trade name "Petro" manufactured by Tosoh Corporation)
Senpaku NC-11PW ", low density polyethylene
, An average particle size of 17 μm) and a plasma treatment.
The same as in Example 1 except that the processing time was 10 minutes.
Thus, a water-repellent coating was obtained. (Comparative Example 1)
Fine particles made of a substrate having an antenna of 90 ° or more are plasma
Except that it was used without treatment, the repellency was the same as in Example 1.
An aqueous coating was obtained. Comparative Example 2 In Example 2, contact with water
Particles consisting of a base material with an antenna angle of 90 ° or more
Except that it was used without treatment, the repellency was the same as in Example 2.
An aqueous coating was obtained. Comparative Example 3 In Example 3, the contact with water
Fine particles made of a substrate having an antenna of 90 ° or more are plasma
Except for using without treatment, the repellent was performed in the same manner as in Example 3.
An aqueous coating was obtained. Comparative Example 4 In Example 4, the contact with water
Fine particles made of a substrate having an antenna of 90 ° or more are plasma
Except for using without treatment, the repellency was the same as in Example 4.
An aqueous coating was obtained. [0051]Evaluation Contact angle with water used in Examples 1-4 and Comparative Examples 1-4
Particles composed of a base material having an angle of 90 ° or more
A large number of them are placed and then compressed, and the resulting flat plate
The contact angle with water in the state without treatment
Was measured in the same manner as the measurement of the contact angle of Table 1.
Are shown as "contact angle of substrate". Examples 1 to 4 and Comparative Examples 1 to 4 were obtained.
Regarding the water-repellent coating,
Table 1, the contact angle of the coating, and the friction resistance were measured.
Was. Exposed surface area of fine particles: Scanning electron micrograph
The ratio of the fine particle exposed surface area was determined from the above. Shooting is on the coating surface
For the 5 mm x 5 mm part, the line was
The area occupied by the image of the fine particle
By dividing by the total area of the imaging unit, the exposed surface area of the fine particles
Was determined. Measurement of contact angle of coating: room temperature 23 ° C, humidity 50%
A small drop of water on the needle tip and place it on the coating.
The contact angle meter (Kyowa Interface Science Co., Ltd.
The contact angle was measured using a contact angle meter CA-D). Measurement of friction resistance: 1 kg / cm of coating^TwoPressured
Paper (made by Jujo Kimberly Co., Ltd., trade name: Kimwipe S
-200 "), and rub the particles 100 times.
-After removal by spraying, the water repellency of the friction part
It measured similarly to the measurement of the contact angle of the coating. [0054] [Table 1] In Table 1, "> 16"
In the case of "0", the water repellency of the coating is high,
Water drops on the coating even when using a trafluoroethylene coated needle
Could not be dropped, and the contact angle 160
In the case of °, water drops could be dropped.
The angle was determined to be 160 ° or more. Example
Water droplets roll down when water droplets are dropped directly on coatings 1-3
Was. For the coating of Example 4, the contact angle was large, but
Did not roll down. [0056] The method for producing a water-repellent coating of the present invention is described above.
Is the base material and the contact angle with water is 90 ° or more
Since the particles that have been subjected to plasma treatment are used,
Improved adhesion to resin coating, excellent particle adhesion to coating
Durability is improved due to the water repellency
A stable water-repellent coating can be obtained. In addition, resin to be a coating film
A wide range of choices can be made to impart water repellency to various substrates.
Can be.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C09K 3/00 112 C09K 3/00 112Z 3/18 104 3/18 104 (56) References A) JP-A-5-124207 (JP, A) JP-A-3-139571 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05D 1/00-7/26 C09K 3 / 00 112 C09K 3/18 104

Claims (1)

(57) [Claims 1] (a) a step of plasma-treating fine particles made of a base material having a contact angle with water of 90 ° or more; (b)
A step of applying a resin to the base to form a resin coating on the base; (c) obtaining the resin coating obtained in the step (b) in the uncured or semi-cured state by the step (a). The plasma-treated fine particles are applied to the resin coating film, and after curing of the resin coating film, the fine particles have a surface area of 20% of the resin coating film.
%; And (d) a step of curing the fine particle-adhered resin coating film obtained in the step (c) and fixing the fine particles to the resin coating film. A method for producing a water-repellent coating, comprising: