JPH1157543A - Spray coating device of polysilazane and spray coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an operation such as transferring on a soln., setting or a device, removing air and the soln. from a soln. passage by providing an injection means of a polysilazane compd.-containing soln. over a range from a bottom part to an upper part in a closed vessel in which the polysilazane compd.-containing soln. and a compressed gaseous nitrogen are enclosed. SOLUTION: The injection means 4 of the polysilazane compd.-containing soln. 1 is provided over the range from the bottom part to the upper part in the closed vessel 3 in which the polysilazane compd.-containing soln. and the compressed gaseous nitrogen 2 are enclosed. The vessel 3 is made of metal such as tinplate and aluminum. In the injection means 4, a button 5 provided with a nozzle 10, a valve 6 and a dip tube 7 are provided, and when the button is pushed, the polysilazane compd.-containing soln. 1 is sprayed from the nozzle 10 of the button 5 through insides of the dip tube 7 and the valve 6, and when the button 5 is returned, the spray is stopped. Parts consisting of the injection means are made of the metal or plastic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polysilazane spray coating apparatus and a spray coating method capable of spray coating a polysilazane compound-containing liquid simply and economically.

[0002]

2. Description of the Related Art Polysilazane, when fired, has corrosion resistance,
It becomes a ceramic with excellent heat resistance, insulation, abrasion resistance, etc., so it can be used as a surface protection film or insulation film for various materials such as metals, ceramics, plastics, etc. It can be used for various applications as a coat film or an alignment film.

Hitherto, as a method for applying such a polysilazane, methods such as dipping, roll coating, bar coating, brush coating, spray coating, and flow coating have been adopted.

In these coating methods, polysilazane is usually used as a solution diluted with an organic solvent. However, polysilazane itself is easily oxidized and hydrolyzed in an oxidizing atmosphere such as air and solidifies. Need to be careful about its handling. Considering such properties of polysilazane, spray coating is relatively easy to handle and has good applicability among the above application methods, so that a good coating is easily obtained.

[0005] There are two types of conventional polysilazane spray coating methods, a one-fluid method and a two-fluid method. The one-fluid method includes a spray gun as a spraying means, and a sealed container A (having a size of, for example, 1 to 5) in which a polysilazane solution is sealed.
Liter, the polysilazane solution is present in an atmosphere of nitrogen gas introduced from container B below) and a closed coating container B filled with compressed nitrogen gas. This is a method of spraying a solution from a spray gun by introducing pressurized nitrogen gas. In the two-fluid method, a sealed container A 'in which a polysilazane solution is sealed (the polysilazane solution exists in an atmosphere of nitrogen gas, as in the one-fluid method), a spray gun as an injection means, and a spray gun from the container A' to a spray gun Using a spray coating apparatus having a pump for supplying the solution and a sealed container B ′ filled with nitrogen gas,
In this method, the solution in the container A 'is introduced into the spray gun by the solution supply pump, and simultaneously, the pressurized nitrogen gas in the container B' is introduced into the spray gun, thereby spraying the solution from the spray gun.

[0006]

However, in the conventional spray coating method of polysilazane, (1) before starting spraying, the solution is stored in a container A or A 'from a storage source of the polysilazane solution in a non-oxidizing atmosphere. Transfer, (2)
Before spraying, set the device to be sprayable. (3) Especially in the case of the two-fluid method, before starting spraying, flow an organic solvent through the solution flow path such as a solution supply pump and its attached pipe, spray gun, etc., and air (4) After the spraying, there is a disadvantage in that it involves a troublesome operation such as removing the solution remaining in the solution flow path by flowing an organic solvent. In addition, since the apparatus is complicated and large, and a small amount of the residual solution after spraying needs to be removed as described above, there are disadvantages that it is inconvenient and uneconomical, especially when the polysilazane solution is used little by little.

[0007] Under such circumstances, there has been a demand for a spray coating apparatus and a spray coating method capable of spray coating a polysilazane solution simply and economically. SUMMARY OF THE INVENTION The present invention has been made to meet the above-mentioned demands, and a purpose thereof is to provide a spray coating apparatus and a spray coating method capable of simply and economically spray-coating a polysilazane solution without the above-mentioned troublesome work. It is to provide.

[0008]

SUMMARY OF THE INVENTION The present invention provides a closed container in which a polysilazane compound-containing liquid and a compressed nitrogen gas are sealed, and a means for injecting the polysilazane compound-containing liquid, which is provided from the bottom to the top in the container. And a spray coating apparatus for polysilazane, comprising:

The present invention also provides a method for spray coating a polysilazane, which comprises spraying a liquid containing a polysilazane compound from a spraying means of the spray coating apparatus.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a spray coating apparatus according to the present invention comprises a liquid 1 containing a polysilazane compound.
And a sealed container 3 in which compressed nitrogen gas 2 is enclosed,
There is provided a polysilazane compound-containing liquid spraying means 4 provided from the bottom to the top in the container 3. In addition,
5 is a button with a spray nozzle 10, 6 is a valve, 7
Is a dip tube, and 8 is a weight.

The container 3 is made of a metal such as tinplate or aluminum, and its shape is not particularly limited as long as it can withstand the internal pressure, and may be any shape such as a cylinder, a polygon, and a sphere. The capacity of the container 3 is suitably about 0.05 to 1 liter.

The polysilazane compound-containing liquid 1 in the container 3
Is 70% or less, preferably 6%, of the internal volume of the container 3.
0% or less is enclosed. The pressure of the nitrogen gas 2 in the container 3 varies depending on the physical properties of the polysilazane compound-containing liquid, the temperature, the capacity of the container, and the like, but is generally 4 to 12 kg / c.
m ² . Note that an inert gas such as an argon gas can be used instead of the nitrogen gas 2.

The injection means 4 basically comprises a button 5 with a nozzle 10, a valve 6 and a dip tube 7, and when the button 5 is pressed, the polysilazane compound-containing liquid 1 in the container 3 is filled in the dip tube 7 and the valve. It is sufficient if it has a function of spraying from the nozzle 10 of the button 5 through the interior of the button 6 and stopping the spraying when the button 5 is returned. These parts constituting the injection means are made of metal or plastic.

The button 5 and the valve 6 are, for example, shown in FIG.
(However, FIG. 3 shows a state when the button 5 is pressed). In FIG. 3, reference numeral 9 denotes a metal or plastic insert, 11 denotes a rubber stem packing, 12 denotes a rubber gasket packing, 13 denotes a metal or plastic stem, and 14 denotes a part constituting the container 3. A cup 15 is a metal spring made of stainless steel or the like, and 16 is a plastic housing. The container 3 itself and the injection means 4 may use, for example, a can portion and injection means of a commercially available aerosol can.

The spray coating method of the present invention uses such a spray coating apparatus, and as shown in FIG. 2, the nozzle 10 provided on the side of the button 5 is directed toward the object to be coated (not shown). 5, the polysilazane compound-containing liquid 1 in the container 3 may be sprayed from the nozzle 10. That is, when the button 5 is pressed, the polysilazane compound-containing liquid 1 in the container 3 passes through the dip tube 7 and then the valve 6 as shown by the solid arrow due to the pressure of the compressed nitrogen gas 2 in the container 3. To the nozzle 10 of the button 5 from which it is sprayed as indicated by the dotted arrow. To stop spraying, it is sufficient to stop pressing the button 5 and return this button to its original position.

In the method of the present invention, a good coating film can be obtained by such spray coating, but if necessary, after spraying, the coating surface can be further smoothed with a brush, a roll, or the like to obtain a better coating film. be able to. The polysilazane compound used in the present invention includes the following general formula (1):

[0017]

Embedded image (However, R ¹ , R ² and R ³ each independently represent a hydrogen atom; a hydrocarbon group such as an alkyl group, an alkenyl group, a cycloalkyl group and an aryl group; an alkylsilyl group; an alkylamino group; and an alkoxy group. , R ¹ , R ² and R ³ are hydrogen atoms.)

The number average molecular weight having a unit represented by the following formula as a main chain is usually 100 to 50,000, preferably 300 to 5,
000, more preferably 1,000 to 1,400 polysilazane. In addition, a silicon alkoxide-added polysilazane obtained by reacting a silicon alkoxide with the above-mentioned polysilazane by heating (see JP-A-5-238827), and a glycidol-added polysilazane obtained by causing a glycidol to react with a similar polysilazane by heating (Japanese Patent Laid-Open No.
Alcohol-added polysilazane obtained by heating and reacting an alcohol with the same polysilazane (see JP-A-6-240208), and a metal carboxylic acid containing a metal such as nickel, titanium, platinum, and rhodium in the same polysilazane. Metal carboxylate / polysilazane reaction product obtained by reacting a salt (JP-A-6-2991)
No. 18), an acetylacetonato complex-added polysilazane obtained by heating and reacting a similar polysilazane with an acetylacetonato complex (metals constituting the complex are nickel, platinum, palladium, aluminum, rhodium, etc.) 30329) can also be used.

The number average molecular weight of the polysilazane to which the silicon alkoxide or the like is added as described above is usually 100 to 50,000, preferably 300 to 5,000, more preferably, like the polysilazane of the general formula (1). 1,000
~ 1,400.

The above-mentioned polysilazane compound itself is a liquid or a solid having different viscosities depending on the molecular weight and the molecular structure. Therefore, particularly in the case of a low-viscosity liquid, it may be used as it is as a polysilazane compound-containing liquid. In the case of a high-viscosity liquid, various solvents such as hydrocarbon solvents such as xylene (o- or m-xylene), cyclohexane and cyclohexene; ether solvents such as dibutyl ether, etc. It is preferable to use a solution diluted with an organic solvent. Of course, in the case of solid,
Since it cannot be applied as it is, it must be diluted with an organic solvent and used as a solution. Depending on the use of the film to be formed, such a polysilazane compound or a solution thereof may be, for example, a fine powder of a metal such as Ag, Au, Pd, or Ni (see JP-A-7-196986), a pigment, Various additives such as an ultraviolet absorber and an antistatic agent can be added.

Commercially available polysilazane compound-containing liquids include polysilazane NL514 (a 5% by weight xylene solution of polysilazane having a number average molecular weight of 1,200 ± 200) and N-L114 (number average molecular weight of 900 ±) manufactured by Tonen Corporation. 3
5 to 10% by weight xylene solution of polysilazane)
And a 1: 1 (weight) mixture of N-L714 (20% by weight xylene solution of polysilazane having a number average molecular weight of 900 ± 300) and a zinc oxide dispersion as an ultraviolet absorbent-containing liquid.

[0022]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to the following examples. Example 1 After cleaning the inside of an aluminum can for aerosol (having a hole for filling contents at the top) with an AL45 × 150 (outer diameter 45 mm, height 150 mm) by air blowing,
From the above pores, as a polysilazane compound-containing liquid, a 10 wt% xylene solution of polysilazane having a number average molecular weight of 900 ± 300 (Polysilazane NL114 manufactured by Tonen Corporation) 50c
c. Further, a valve 6 with a dip tube 7 as shown in FIG.
The pressure was reduced to Hg, and the valve 6 was fixed to the can.
After filling with 5 kg / cm ² of nitrogen gas from the upper end of the valve, the upper end of the valve was sealed with a button 5 to produce a spray coating device (hereinafter referred to as a spray can). The nozzle of this spray can was pointed at a 30 cm × 30 cm × 3 mm soda lime glass substrate and a button was pressed to spray coat the polysilazane solution in the can. 6
And then cured at room temperature for 3 days to obtain a uniform and smooth coating. Load of this coating 1k
When the pencil hardness in g was measured in accordance with JIS K5400, it was as high as 9H or more.

Example 2 As a polysilazane compound-containing liquid, the number average molecular weight was 1,2.
Example 1 except that a 5% by weight xylene solution of 00 ± 300 polysilazane (Polysilazane N-L514, Tonen Co.) was used and nitrogen gas of 7 kg / cm ² was used.
A spray can was manufactured in the same manner as in Example 1. By pressing the button of the nozzle of this spray can toward a 30 cm × 30 cm × 1 mm stainless steel (SUS304) substrate, the polysilazane solution in the can was spray-coated,
When the coated surface was smoothed with a brush and cured at 150 ° C. for 2 hours, a uniform and smooth coating was obtained. Load of this coating 1
When the pencil hardness in kg was measured in accordance with JIS K5400, it was as high as 9H or more. The obtained coated and uncoated stainless steel substrates were 10%
When immersed in a hydrochloric acid aqueous solution at room temperature for 10 minutes, corrosion was observed on the uncoated material, whereas almost no corrosion was observed on the coated material.

[0024]

According to the spray coating apparatus of the present invention, transfer of a solution in a non-oxidizing atmosphere, setting of the apparatus, displacement of air from the solution flow path, and Spray coating of the solution can be carried out simply and economically, without the need for cumbersome work such as removal of the solution, as in the case of an ordinary paint aerosol spray can. In addition, the apparatus of the present invention does not cause clogging of the nozzle during or after spraying without performing the above-mentioned operations, and requires a separate closed container (storage container) for nitrogen gas and a solution supply pump as in the prior art. Since there is no need to provide them, there are advantages such as compactness and miniaturization, and effective use of the solution even in small quantities without waste.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an example of a spray coating apparatus of the present invention.

FIG. 2 is a diagram showing a state when the apparatus of FIG. 1 is used.

FIG. 3 is a partially enlarged cross-sectional view of an example of an injection unit constituting the spray coating apparatus of the present invention.

[Explanation of symbols]

 1) Polysilazane compound-containing liquid 2) Compressed nitrogen gas 3) Closed container 4) Injection means 5) Button 6) Valve 7) Dip tube 10) Nozzle

Claims (2)

[Claims] 1. A polysilazane spray coating comprising: a closed container in which a polysilazane compound-containing liquid and a compressed nitrogen gas are enclosed; and a means for spraying the polysilazane compound-containing liquid provided from the bottom to the top in the container. apparatus. 2. A method for spray-coating polysilazane, comprising spraying a liquid containing a polysilazane compound from a spraying means of the spray coating apparatus according to claim 1.