JPH0924308A - High speed curing reaction type spray gun for two-pack mixed coating and coating method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly form a film even when coating is frequently started and stopped and to prevent a hardened residue of resin from remaining in a spray gun main body by setting the inside diameter of the spray gun main body and the center-to-center distance between the feeding parts of the 1st and the 2nd liquids so that they can satisfy a specific formula. SOLUTION: The 1st coating liquid feeding pipe 15 and the 2nd coating liquid feeding pipe 16 are respectively connected to the 1st coating liquid tank and the 2nd coating tank to feed the 1st and the 2nd coating liquids necessary for coating. The 1st coating liquid feeding port 15a and the 2nd coating liquid feeding port 16a provided inside a coating material mixing part 17 are set so that an inside diameter D of a spray gun main body and a center-to-center distance L between the feeding port 15a and the feeding port 16a can satisfy L/D(%)=0 or 10<=L/D(%)<=50, where 0<D. In this spray gun, the 1st and the 2nd liquids are respectively made of an isocynate compound and an amine compound and, within gelling time on two-pack mixing of about 40sec, a polyurethane resin film is properly formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for anticorrosion lining construction in the field of steel structures, concrete structures, etc. exposed to severe corrosive environments, and particularly for the anticorrosion lining when returning to the current state at the time of repairing them. The present invention relates to a high-speed curing reaction type spray gun for two-component mixed coating suitable for construction and a coating method using the same.

[0002]

2. Description of the Related Art Conventionally, various types of spray guns for two-component mixed coating have been known. For example, Japanese Patent Application Laid-Open No. 2-2
Japanese Patent No. 37669 (Prior Art 1) discloses a spray gun in which a plurality of fluids are mixed inside a gun by a static mixer and sprayed from a nozzle. As shown in FIG. 6, the spray gun includes a curing agent injection nozzle 6 in a mixing portion 5 of a gun head 4 on which a tip of a needle valve 3 which is advanced and retracted by a trigger 2 inserted in the center of a spray gun main body 1 is seated. Along with the arrangement, a cleaning liquid intake portion 8 is provided in front of the needle valve 3 and in front of the paint discharge cap 7, so that the mixing portion 5 ahead of the needle valve 3 is washed.

The needle valve 3 is actuated, the valve portion 3a is retracted to introduce the main agent into the mixing section 5 through the main agent supply port 9, and the second needle of a sub-gun (not shown) simultaneously actuated by the operation of the trigger 2 is operated. The valve retracts, and the curing agent is injected from the curing agent injection nozzle 6 whose tip faces the mixing section 5 through the discharge pipe, and the main agent mixed with the curing agent is agitated and mixed by the static mixer 10 and then mixed. Nozzle 11 at the tip
It is injected more.

[0004]

In recent years, as a coating material used in this type of spray gun, it has been often the case that a resin having a fast curing reaction such as an isocyanate compound and an amine compound is mixed to develop the performance. ing. Since the curing speed in the above curing reaction is extremely high, the following problems occur.

The mixed liquid is hardened in the gun body, making spraying impossible. Unable to mix uniformly in the gun body, and the expected film performance cannot be obtained. As a result of hardened resin residues remaining in the gun body, the spraying operation is interrupted for cleaning.

In the spray gun shown in the prior art 1, when the coating operation is interrupted, the main agent mixed with the curing agent remains on the downstream side of the mixing section 5 of the spray gun main body 1, so that the time elapses. The curing reaction progresses, and it becomes easy to cause spray failure or defective spray during the next spraying work. Therefore, it is necessary to open a valve for a cleaning liquid (not shown), introduce acetone, which is the cleaning liquid, into the mixing portion 5 from the cleaning liquid intake portion 8 and discharge the residual coating material from the ejection port of the nozzle 11 to eliminate the curing coating material.

When this type of spray gun is used for coating work, generally, coating is carried out by repeating a procedure of stopping and starting by a trigger operation. However, since the coating work with the spray gun of the prior art 1 is a procedure of stopping, washing, and starting, there is a high frequency of washing with the washing liquid during use, and therefore the painting work cannot be performed smoothly.

Further, at the time of stopping and starting the coating of the spray gun, the cleaning liquid is mixed in the film formed by spraying, and the expected film performance cannot be obtained. Further, when the coating of the spray gun is stopped, the main agent mixed with the curing agent existing on the downstream side of the mixing section 5 of the spray gun body 1 is washed with a washing liquid and discarded.

Therefore, an object of the present invention is to solve the above-mentioned problems, to use a resin having a fast curing reaction such as an isocyanate compound and an amine compound, and to frequently stop and start coating by a spray gun. A high-speed curing reaction type spray gun for two-component mixed coating, which can form a uniform film regardless of them, and can prevent resin curing slag from remaining in the spray gun body, and a coating method using the same. To provide.

[0010]

According to a first aspect of the present invention, there is provided a high-speed curing reaction type spray gun, a spray gun main body having a nozzle at a tip thereof, and a nozzle opening portion provided inside the spray gun main body. The spray gun includes a slidable valve body that opens and closes, and first and second liquid supply ports that are provided in the spray gun body and that are opened and closed on the valve body circumferential surface by sliding of the valve body. The inner diameter (D) of the gun body and the center-to-center distance (L) between the supply ports for the first and second liquids are given by the following equation (1) L / D (%) = 0 ───── (1) It is characterized in that 0 <D 1 is satisfied.

According to a second aspect of the present invention, there is provided a high-speed curing reaction type spray gun, which is provided inside the spray gun main body having a nozzle at its tip, and is slidable for opening and closing the nozzle opening. The spray gun body is provided with a valve body and first and second liquid supply ports which are provided on the spray gun body and are opened and closed on the valve body circumferential surface by sliding of the valve body. D) and the center-to-center distance (L) between the supply ports for the first and second liquids satisfy the following equation (2): 0 <L / D (%) ≦ 50 ────── (2) It is characterized by what has been done.

The method of the present invention according to claim 3 uses the high-speed curing reaction type spray gun for two-component mixed coating of the invention according to claim 1 or 2, and uses the first and second solutions. An isocyanate compound and an amine compound are used, and the gel time at the time of mixing two liquids is characterized by forming a polyurea resin film within 40 seconds.

The method of the present invention according to claim 4 uses the high-speed curing reaction type spray gun for two-component mixed coating of the invention according to claim 1 or 2, and uses the first and second liquids. It is characterized by using an isocyanate compound and a polyol to form a polyurethane film within a gel time of 40 seconds when the two liquids are mixed.

[0014]

According to the first or second aspect of the present invention, the nozzle opening portion and the first and second liquid supply ports are slidably opened and closed by one valve body, which will be described later. As shown in the test example, the ratio L / D between the center distance L between the first liquid supply port and the second liquid supply port and the gun body inner diameter D
Is set to 0 to 50% by using a resin having a fast curing reaction such as an isocyanate compound and an amine compound, or an isocyanate compound and a polyol, and frequently stopping and starting the coating of the spray gun. However, a uniform film can be formed irrespective of them, and the cured residue of the resin does not remain in the spray gun body.

The lower limit of L / D should be 0 or closer to 0. If L / D exceeds 50%, when coating is stopped,
At the start, a deviation occurs in the mixing ratio of the two liquids, and the breaking strength of the coating resulting from this is reduced. Therefore, it becomes difficult to achieve the object of the present invention.

According to the invention of claim 3 or 4, L / D of the invention of claim 1 or 2 is 0.
By using a rapid curing reaction type spray gun for two-component mixed coating having a first liquid supply port and a second liquid supply port in the range of ˜50%, an isocyanate compound and an amine compound, or It is possible to form a polyurea resin film or a polyurethane film by setting the gel time at the time of mixing two liquids of an isocyanate compound and a polyol within 40 seconds.

If the gel time exceeds 40 seconds, the normal curing reaction of the two-component mixed coating is performed, and it is not suitable for the anticorrosion lining construction that restores the current state at the time of repairing steel structures, concrete structures and the like. The two liquids of the isocyanate compound and the amine compound, or the isocyanate compound and the polyol, in which the gel time at the time of mixing is 40 seconds or less, are used for the first time using the rapid curing reaction type spray gun of the invention according to claim 1 or 2. Mixing can be made uniform and a uniform coating film can be formed.

In the case of coating using the spray gun for two-component mixed coating of the present invention, the valve body inserted up to the nozzle opening of the spray gun main body is pulled to supply two coating liquids to the spray gun main body. Open the mouth and introduce the two coating liquids into the gun body, mix them in the spray gun body, and spray the mixture liquid from the nozzle for coating.

To stop spraying the mixed liquid, insert the valve body up to the nozzle opening of the spray gun body, and
Close the two paint fluid supply ports. As a result, the resin slag does not remain in the spray gun body.

Next, the present invention will be described with reference to the drawings. FIG. 1 is a schematic overall view of a spray gun for two-component mixed coating of the present invention, and FIG. 2 shows a first embodiment of the present invention, in which the inner diameter (D) of the spray gun body and the first and second FIG. 2 is an enlarged cross-sectional view of a main part of a spray gun in which a center distance (L) between two liquid supply ports satisfies the following expression (1). L / D (%) = 0 ───── (1) where 0
<D

FIG. 3 shows a second embodiment of the present invention.
FIG. 1 is an enlarged cross-sectional view of a main part of a spray gun in which an inner diameter (D) of a spray gun body and a center-to-center distance (L) between first and second liquid supply ports satisfy the following expression (2). is there. 0 <L / D (%) ≦ 50 ──── (2)

As shown in FIG. 1, the spray gun body 12
Is a first coating liquid supply pipe 15 and a second coating liquid supply pipe 16
Paint mixing section 1 having a nozzle 13 at the tip, which is connected to
7, a valve body 14 inserted into the paint mixing section 17, and a valve body cylinder 18 having a mechanism for sliding the valve body 14.
And a handle 19 attached to the valve body cylinder 18 and a valve body sliding trigger 20.

In the spray gun of the first embodiment shown in FIG. 2, the paint mixing section 17 has an inner diameter D of the inside of the paint mixing section 17 and a supply port 15a of the first paint liquid supply pipe 15.
And the supply port 16a of the second coating liquid supply pipe 16 are the supply port 1
The center-to-center distance L between the 5a and the supply port 16a is 0
They are provided at different points on the same peripheral surface. In the illustrated example, the supply port 15a and the supply port 16a are provided at positions facing each other.

A nozzle 13 is attached to the tip of the paint mixing section 17, and the passage 17a has an opening 13 of the nozzle 13.
a. The valve body 14 is the passage 1 of the paint mixing section 17.
It is inserted into the paint mixing part 17 from the other end side of 7a and slides to close the opening 13a of the nozzle 13 at the tip of the valve body 14, and the supply port 15a and the supply port 16a can be closed at its peripheral surface. It is like this. The paint mixing unit 17 and the nozzle 13 can be disassembled and assembled.

In the spray gun of the second embodiment shown in FIG. 3, the inside of the paint mixing section 17 has an inside diameter D, and
The supply port 15a of the coating liquid supply pipe 15 and the supply port 16a of the second coating liquid supply pipe 16 are the supply port 15a and the supply port 16a.
Are provided at the positions facing each other in the passage 17a with a distance L between the centers therebetween, thereby promoting the mixing of the two coating liquids.

As in the case of FIG. 2, the nozzle 13 is attached to the tip of the paint mixing section 17, and the passage 17a communicates with the opening 13a of the nozzle 13. The valve body 14 is arranged such that the paint mixing section 17 is provided from the other end side of the passage 17a of the paint mixing section 17.
It is inserted into the inside of the nozzle 13 and slides into the nozzle 13 at the tip of the valve body 14.
The opening 13a is closed, and the supply port 15a and the supply port 16a can be closed by the peripheral surface thereof. The paint mixing unit 17 and the nozzle 13 can be disassembled and assembled.

As shown in FIG. 1, the valve body cylinder 18 having a mechanism for sliding the valve body 14 comprises a paint mixing section 17
Is provided close to. The valve body 14 expands and contracts in the valve body cylinder 18 by an air cylinder type, and by operating the trigger 20, the sliding of the paint mixing section 17 in the passage 17a can be instantaneously performed. In the illustrated example, the valve body 14
However, the present invention is not limited to this.

The first coating liquid supply pipe 15 and the second coating liquid supply pipe 16 are connected to unillustrated tanks for the first coating liquid and the tank for the second coating liquid via hoses, respectively, for coating. Are supplied with the first coating liquid and the second coating liquid required.

In the present invention, FIG. 1, FIG. 2 or FIG.
The first paint liquid supply port 15a and the second paint liquid supply port 16a, which are provided inside the paint mixing section 17, are shown in FIG. 2 between the inner diameter D of the spray gun body 11 and the center between the supply ports 15a and 16a. It is necessary that the distance L be provided so as to satisfy the following expression (1) or expression (2). L / D (%) = 0 (0 <D) ──── (1) 0 ≦ L / D (%) ≦ 50 ───── (2)

[0030]

EXAMPLES The above range is based on the test results according to the following examples. A. Main specifications of spray gun Gun body inner diameter D of spray gun: 3 mm The center-to-center distance L between the supply port 15a and the supply port 16a is changed. The diameter of the supply port 16a and the supply port 17a is 0.5 mm. Isocyanate compound (viscosity 15
00 Poise). Amine compound (300 poise) is supplied from the supply port 16a. Gel time: 15 seconds

B. Main specifications of paint spraying conditions Liquid temperature: 72 ° C Liquid pressure: 150 kg / cm ²

A polyethylene film coated with a release agent by mixing the isocyanate compound and the amine compound in the spray gun body while changing the center distance L between the supply port 15a and the supply port 16a of the spray gun. Test pieces No. 1 to No. 11 were prepared by coating on the above and isolating the formed film.

With respect to the test pieces No. 1 to No. 11, as the film characteristics, the tensile strength (breaking strength) of the isolated coating film (kg / c)
m ² ) and the solvent extraction amount (%) in the isolated film were measured. JIS No. 3 dumbbell was used for the breaking strength. In addition, a mixed solvent in which the ratio of acetone and toluene was 7: 3 was used for measuring the solvent extraction amount (%). Table 1 shows the test results.

[0034]

[Table 1]

Further, the tendency shown in FIGS. 4 and 5 was examined from the above test results. FIG. 4 is a diagram showing the relationship between L / D (%) and breaking strength (kg / cm ² ). As is clear from FIG. 4, when L / D (%) exceeds 50%, the breaking strength (kg / cm ² ) is remarkably reduced. Also, L /
When D (%) was less than 17 (%), very good breaking strength (kg / cm ² ) was obtained.

FIG. 5 is a diagram showing the relationship between L / D (%) and the extracted amount (%). As is clear from FIG. 5, L / D
When the (%) exceeded 50%, the extracted amount (%) was remarkably high. The reason is that the curing reaction between the isocyanate compound and the amine compound did not proceed sufficiently and the unreacted material was extracted.

Further, instead of the isocyanate compound and the amine compound, the isocyanate compound and the polyol were used, and the gel time during mixing was set to 30 seconds, and the rapid curing reaction was similarly performed to form a film. The breaking strength in this case is
L / D (%) is 13%, 390 kg / cm ² , L / D
(%) Was 17% and 380 kg / cm ² , L / D (%) was 27% and 290 kg / cm ² , and L / D (%) was 64% and 160 kg / cm ² .

From the above test results, it was found that the same tendency as in the case of the isocyanate compound and the amine compound was observed. Also, regarding the extracted amount (%), the same results as in the case of the isocyanate compound and the amine compound were obtained.

As shown in the above embodiments, the spray gun of the present invention has the following effects. Even if the coating is stopped and started repeatedly, the rapid curing reaction of two coating liquids such as an isocyanate compound and an amine compound, or an isocyanate compound and a polyol can be made sufficiently uniform. When the coating is stopped, the valve body is inserted until the opening of the nozzle is closed, so that the mixed liquid does not remain. Since the two liquid supply ports in the spray gun main body are provided at opposite positions of the passage and within a range where the center-to-center distance is limited, the two liquids can collide with each other for uniform mixing, which is shown in the prior art. You don't need a static mixer like that.

[0040]

As described above, according to the present invention,
Uses a resin that cures quickly, such as an isocyanate compound and an amine compound, and stops painting with a spray gun.
Even if it is started frequently, a uniform film can be formed irrespective of them, and the cured residue of the resin does not remain in the spray gun body, which is an excellent industrial effect.

[Brief description of drawings]

FIG. 1 is a schematic overall perspective view showing an example of a spray gun of the present invention.

FIG. 2 shows a first embodiment of the spray gun of the present invention,
The center-to-center distance between the supply ports for the first and second liquids is L = 0,
It is a principal part expanded sectional view in case an inside diameter is 0 <D.

FIG. 3 shows a second embodiment of the spray gun of the present invention,
FIG. 6 is an enlarged cross-sectional view of a main part when the distance between centers (the distance between centers / the inner diameter) between the supply ports for the first and second liquids is 0 <L / D (%) ≦ 50.

FIG. 4 is a diagram showing a relationship between L / D and breaking strength according to an example of the present invention.

FIG. 5 is a diagram showing a relationship between L / D and an extracted amount (%) of the present invention.

FIG. 6 is a diagram showing an example of a conventional spray gun.

[Explanation of symbols]

 12 Spray Gun Main Body 13 Nozzle 13a Nozzle Opening 14 Valve Body 15 First Paint Liquid Supply Pipe 15a First Paint Liquid Supply Port 16 Second Paint Liquid Supply Pipe 16a Second Paint Liquid Supply Port 17 Paint Mixing Section 18 Valve Body Cylinder 19 Handle 20 Valve body sliding trigger

Front page continuation (72) Inventor Shin Miyahara 1-20-1, Shimotani-cho, Tsurumi-ku, Yokohama-shi, Kanagawa (72) Inventor Yoshitochi Miyazaki 286-5-6 Suzuki-cho, Kodaira-shi, Tokyo S-5 Mitsui Oil & Kodaira Shrine ( 72) Inventor Kaho Kobayashi 527-2 Takamushi, Oita, Hasuda City, Saitama Prefecture

Claims (4)

[Claims] 1. A spray gun body having a nozzle at its tip, a slidable valve body provided inside the spray gun body for opening and closing the nozzle opening, and a valve provided on the spray gun body. A first and a second liquid supply port opened and closed on the valve body peripheral surface by sliding the body, and the inner diameter (D) of the spray gun body and the first and second liquid supply ports.
A high-speed curing reaction type spray gun for two-component mixed coating, characterized in that the center distance (L) between the liquid supply ports satisfies the following formula (1). L / D (%) = 0 ───── (1) where 0 <D 2. A spray gun main body having a nozzle at the tip, a slidable valve body provided inside the spray gun main body to open and close the nozzle opening, and a spray gun main body provided with the valve. A first and a second liquid supply port opened and closed on the valve body peripheral surface by sliding the body, and the inner diameter (D) of the spray gun body and the first and second liquid supply ports.
A high-speed curing reaction type spray gun for two-component mixed coating, characterized in that the center distance (L) between the liquid supply ports satisfies the following expression (2). 0 <L / D (%) ≦ 50 ──── (2) 3. A rapid curing reaction type spray gun for two-component mixed coating according to claim 1 or 2, wherein the first and second liquids are an isocyanate compound and an amine compound, and two liquids are mixed. Forming a polyurea resin film with a gel time of 40 seconds or less, a coating method using a rapid curing reaction type spray gun for two-component mixed coating. 4. A high-speed curing reaction type spray gun for two-component mixed coating according to claim 1 or 2, wherein the first and second liquids are an isocyanate compound and a polyol, and when two liquids are mixed. A coating method using a rapid curing reaction type spray gun for two-component mixed coating, characterized in that a polyurethane film is formed within a gel time of 40 seconds or less.