JPH08406B2 - Coating method of coating liquid such as surface modifier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention mainly applies a surface modifier such as an antistatic agent or an antifogging agent, a coloring agent, an adhesive agent or the like to the outer peripheral surface of a molded product such as a synthetic resin, and further The present invention relates to a coating method of a coating liquid used for coating food additives and the like.

[0002]

2. Description of the Related Art A molded product made of a synthetic resin is liable to generate static electricity, and there is a possibility that printing or the like will be incomplete under the influence of the static electricity during painting or printing after molding. Therefore, a synthetic resin material is fed between the male mold and the female mold, and the male mold is pressed against the female mold to mold a molded product such as a synthetic resin, and then an antistatic agent is applied to the outer peripheral surface of the molded product. Etc. are applied. In this, a molded product immediately after molding is suspended by an appropriate jig, and in that state, a coating liquid such as an antistatic agent is sprayed.

[0003]

However, in this conventional coating method, peeling electrification occurs at the time of releasing the molded product from the male mold or the female mold, and 50 to 1 while discharging to these molds.
In many cases, static electricity of 00 KV is generated. Therefore, when spraying a coating liquid such as an antistatic agent on a molded product immediately after molding,
Due to the influence of the lines of electric force due to these static electricity, a discharge pattern is formed and uneven coating is likely to occur. Therefore, there is a drawback that a uniform coating film cannot be obtained. This is because the smaller the applied particles are, the more easily they are affected by the lines of electric force, and therefore, there is a possibility that the particles are particularly troubled when the particles are sprayed to form a thin film.

Therefore, as shown in JP-B-63-36627, a solution containing a surface modifier is made into an aerosol consisting of a large number of particles, and one or both of a male mold and a female mold at the time of molding a synthetic resin is released. An aerosol is sprayed in a decompressed atmosphere between these molds, which sometimes occurs, to adhere the above-mentioned aerosol to the surface of the molded product released from the mold, and at the same time to cool the molded product, a pole composed of a surface modifier on the surface of the molded product Methods have been developed for forming thin films.

However, this method requires a completely closed chamber for providing a reduced pressure atmosphere between the molds, which is a large scale in that respect. Further, there is a limit to the amount of aerosol that can be sucked and attached, and it is not suitable for applying an arbitrary amount. Further, although the static electricity can be removed, the suction force is weak to form a film having an antistatic effect.

Therefore, the object of the present invention is to provide a method for applying a coating solution which enables uniform application of these synthetic resin products immediately after molding with a mold without being affected by static electricity. .

[0007]

According to a first aspect of the present invention, there is provided a method for forming a molded product by injecting a raw material between one mold and the other mold, wherein at least one mold is a mold or the like. Of a conductor or semiconductor with a large electrostatic capacity, and when the other mold is released after molding, spray the appropriate coating liquid with the molded product in contact with or close to one mold to expose the outer periphery of the molded product. Form a coating film made of the coating liquid on the surface, then spray the coating liquid on the remaining outer peripheral surface of the molded product in a state where the molded product is separated from one mold by an ejector pin or the like to form a coating film, The coating method was a coating solution such as a surface modifier.

According to a second aspect of the present invention, in a method for molding a molded product by injecting a raw material between one mold and the other mold, both molds are conductors having a large electrostatic capacitance such as a mold. Alternatively, when the mold is made of a semiconductor and the other mold is released after molding, an appropriate coating liquid is sprayed in a state where the molded product is in contact with or close to one mold, and the coating liquid is applied to the exposed outer peripheral surface of the molded product. A film is formed, and then the molded product is separated from one mold with an ejector pin, etc., and the coating liquid is sprayed on the remaining outer peripheral surface of the molded product while the other mold is closer to the molded product than the one mold. Then, a coating solution such as a surface modifier was applied to form a coating film.

According to a third aspect of the present invention, in a method for forming a molded product by injecting a raw material between one mold and the other mold, at least one mold has a capacitance of a mold or the like. It consists of a large conductor or semiconductor, and when the other mold is released after molding, the solution of the antistatic agent is sprayed while the molded product is in contact with or close to one mold to prevent static charge on the exposed outer peripheral surface of the molded product. A coating film made of an antistatic agent is formed by spraying a solution of the antistatic agent onto the remaining outer peripheral surface of the molded article while forming a coating film made of the agent and then separating the molded article from one mold with an ejector pin or the like. A coating solution such as a surface modifier was used to form a film.

[0010]

According to the invention of claim 1, since at least one of the molds is made of a conductor or semiconductor having a large electrostatic capacity such as a mold, when the other mold is released after molding, the molded product is released from the mold. Static electricity due to peeling electrification occurs on the surface, and lines of electric force try to generate in the direction of the other mold due to this static electricity, but because the capacitance of one mold that is in contact with the molded product in this state is large, Pull the electric lines of force to this one mold,
No lines of electric force are generated from the release surface. Therefore, in this state, an appropriate coating liquid is sprayed on the release surface of the molded product. At this time, the same action occurs even when the molded product is brought into close proximity without being brought into contact with one mold. According to Paschen's law, the discharge potential is 1
It is 30 KV at 0 mm, and therefore becomes 3 KV at 1 mm, and generally a discharge pattern cannot be obtained at 3 KV. Therefore, the molded product may be in a close state in which it is separated from the one mold by about 1 mm.

In the invention of claim 2, since both molds are composed of a conductor or semiconductor having a large electrostatic capacity such as a mold, when the other mold is released after molding, the mold release surface of the molded product. Static electricity is generated due to peeling and charging, and lines of electric force try to generate in the direction of the other mold due to this static electricity, but in this state the molded product is in contact with or in close proximity. , The electric force line is drawn toward the one of the molds, and the electric force line is not generated from the release surface. Therefore, in this state, an appropriate coating liquid is sprayed on the release surface of the molded product. Further, after this, the molded product is separated from one mold by an ejector pin or the like, and since the other mold is brought closer to the molded product than the one mold, an electric force line is generated due to peeling charging at the time of mold release. However, since the electric force lines are directed in the direction of the other mold that is closer, the influence of the electric force lines on the release surface of the molded product is small. In this state, the antistatic agent solution is sprayed onto the outer peripheral surface of the mold release of the molded product.

In the invention of claim 3, since at least one of the molds is composed of a conductor or semiconductor having a large electrostatic capacity such as a mold, when the other mold is released after molding, the molded product is released from the mold. Electrostatic force is generated on the surface due to peeling charging, and lines of electric force try to generate in the direction of the other mold due to this static electricity, but the molded product is in contact with or in close proximity in this state, and the capacitance of one mold is large. Therefore, the line of electric force is drawn toward the one of the molds, and no line of electric force is generated from the release surface. Therefore, an appropriate coating liquid is sprayed in this state. Also, after this, when the molded product is separated from one mold by an ejector pin, etc., the antistatic layer is formed on one side surface of the molded product as described above. Is directed to this antistatic layer and does not occur on the release surface of the molded product. In this state, the antistatic agent solution is sprayed onto the outer peripheral surface of the mold release of the molded product.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First, a schematic configuration diagram of a molding apparatus and a molding die for molding synthetic resin used in the present invention will be described with reference to FIG. A female fixed mold 2 made of a conductor having a large electrostatic capacity is provided at the tip of the molding machine 1, and the fixed mold 2 is provided so as to face the fixed mold 2.
A male movable mold 3 made of a conductor having a large electrostatic capacity is provided so as to be freely contactable with. The raw material entered from the hopper of the molding machine 1 is kneaded by the screw, reaches the ejection port 4, and enters the void in the hollow mold 5 formed by the fixed mold 2 and the movable mold 3. . The movable die 3 is supported by an extendable and retractable arm 6, and is brought into contact with or separated from the fixed die 2 by the extendable and retractable arm 6.

As shown in FIG. 2, nozzle chambers 7 which are slidable in parallel with the movable mold are provided on both sides between the fixed mold 2 and the movable mold 3, and each of these nozzle chambers 7 is provided. A flexible pipe 9 is introduced from the aerosol generator 8. Further, between these nozzle chambers 7, an aerosol suction body 10 is provided below the fixed mold 2 and the movable mold 3, and a feedback circuit for returning from the aerosol suction body 10 to the aerosol generator 8 through the pipe 11 and the blower 12. Is provided.

Explaining the method of the present invention, the telescopic arm 6 is actuated in advance to bring the movable mold 3 into contact with the fixed mold 2 as described above to form a hollow mold 5, and the hollow mold 5 is formed. The raw material is filled from the molding machine 1 into the space of the mold 5. Then, a molded product 13 of synthetic resin is molded by the mold 5. After molding, the telescopic arm 6 is operated to move the fixed mold 2 to the movable mold 3.
Pull apart. Thereby, the convex portion 3a of the male movable die 3 is formed.
The molded product 13 is attached to the outer periphery and is separated from the fixed mold 2. Then, as shown in FIGS. 2 and 3, the antistatic agent solution is sprayed in a state where the molded product 13 is in contact with one movable mold 3.

To this end, a solution of the antistatic agent is made into an aerosol composed of a large number of particles by an aerosol generator 8, and the aerosol is sprayed onto the molded product 13 from each nozzle chamber 7 located on both sides of the molded product 13 through each flexible pipe 9. .
Then, the aerosol suction body located below the molded product 13 is actuated to suck the aerosol that has not adhered to the molded product 13, and returns it to the aerosol generator 8 through the pipe 11 and the blower 12. In this manner, as shown in FIG. 4, a coating film 14 made of an antistatic agent is formed on the exposed outer peripheral surface of the molded product 13.
Are formed (though the coating film 14 is shown thick in the figure for convenience of explanation, it is actually extremely thin compared to the molded product 13).

When the movable mold 3 is separated from the fixed mold 2 after the molded product 13 is molded in this manner, static electricity is generated on the mold release surface of the molded product 13 due to peeling charging, and the static electricity causes the lines of electric force to move to the fixed mold 2. , But in this state the molded product 13
Since the electrostatic capacity of the movable die 3 which is in contact with is large, the electric force line is pulled in the direction of the movable die 3 and the electric force line is not generated from the release surface. Therefore, in this state, the solution of the antistatic agent is sprayed onto the release surface of the molded product 13 so that the coating film 1
No unevenness occurs in 4 and becomes uniform.

After that, the ejector pin 15 is projected from the outer periphery of the convex portion 3a of the movable mold 3 by an appropriate means to support the molded product 13 by the ejector pin 15 as shown in FIG.
As shown in FIG. 6, the antistatic agent solution is aerosolized on the remaining outer peripheral surface of the molded product 13 in the state of being separated from the outer periphery of the convex portion 3a of the movable mold 3 in the same manner as described above and sprayed from each nozzle chamber 7. A coating film 16 is provided. Molded product 1 from this movable mold 3
When 3 is released, static electricity due to peeling charge is generated and electric lines of force tend to be generated in the direction of the movable mold 3. However, as shown in FIG. 5, a coating film of an antistatic agent is formed on one side of the molded product 13. Since the coating film 14 is provided, the lines of electric force are directed to the antistatic layer of the coating film 14, and the lines of electric force are not generated on the release surface from the movable die 3. Therefore, in this state, the solution of the antistatic agent is sprayed on the release surface of the molded product 13 from the movable mold 3, so that the coating film 16 is uniform and uniform. In this way, as shown in FIG. 7, a uniform antistatic film layer 17 is formed on the entire outer peripheral surface of the molded product 13.
Can be formed.

Although the antistatic film layer 17 is formed on the outer peripheral surface of the molded product 13 in the above embodiment, the present invention is not limited to this, and the present invention is also applied when an appropriate coating liquid is sprayed on the outer peripheral surface of the molded product. it can. However, when spraying a coating liquid other than the antistatic agent solution, when the movable mold 3 is separated from the fixed mold 2 and the molded product 13 is separated from the fixed mold 2 in the above-described embodiment, the same as in the above-described embodiment. The coating film 14 can be formed without being affected by the lines of electric force due to static electricity, but when the molded product 13 is released from the movable die 3, it is affected by the lines of electric force. Therefore, in this case, a uniform coating film is formed only on the outer peripheral surface of the molded product 13.

Further, when spraying a coating liquid other than the antistatic agent solution, as shown in FIG.
When separated from the fixed mold 2, the fixed mold 2 is kept close to the molded product 13. As a result, the movable die 3 to the ejector pin 15
When the molded product 13 is released from the mold, electric force lines due to static electricity tend to be generated on this release surface, but since the electric force lines are directed to the fixed mold 2 side closer to this molded product 13, the movable mold 3 No static electricity is generated on the release surface of and, and the coating liquid can be uniformly applied.

In the above embodiment, the coating liquid was sprayed on the exposed outer peripheral surface of the molded product while the molded product was in contact with one of the molds having a large electrostatic capacitance. The same effect can be obtained by spraying the products in close proximity. Further, in the above-mentioned embodiment, one or both of the molds is a conductor having a large electrostatic capacity, but the present invention is not limited to this, and a mold made of a conductor or a semiconductor having a large electrostatic capacity may be used. The above-mentioned molding machines include appropriate ones such as compression molding, injection molding, and vacuum molding, and the present invention broadly includes those that spray an appropriate coating liquid onto a molded product immediately after release from the mold.

[0022]

According to the invention of claim 1, one of the molds is composed of a conductor or a semiconductor having a large electrostatic capacitance such as a mold in applying an appropriate coating liquid to the outer peripheral surface of the molded product. , When the other mold is released after molding, static electricity is generated on the release surface of the molded product due to peeling charging, and this static electricity causes lines of electric force to be generated in the direction of the other mold. Since one of the molds that is in contact with or close to has a large electrostatic capacitance, the electric force line is drawn in the direction of the one mold, and the electric force line is not generated from the release surface. Therefore, it is possible to uniformly apply an appropriate coating liquid to one release surface of the molded product without being affected by static electricity in this way, and especially when a thin coating film is to be provided, particles of the coating liquid are Although it is small, even such fine particles are sprayed without being affected by static electricity,
It can be applied and a uniform ultrathin film can be obtained.

According to the invention of claim 2, in addition to the effect of the invention of claim 1, an appropriate coating liquid can be uniformly applied to both release surfaces of the molded product.

Furthermore, the invention of claim 3 is suitable for forming an antistatic layer on the outer peripheral surface of a molded product, and a solution of an antistatic agent is made into a large number of fine particles to form an extremely thin film on the outer peripheral surface of the molded product. In doing so, the antistatic layer can be formed quickly and uniformly without being affected by static electricity.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus used in the method of the present invention.

FIG. 2 is a schematic configuration diagram of an aerosol spraying device used in the method of the present invention.

FIG. 3 is a schematic view showing a state in which a mold product is locked in one mold and a coating liquid is sprayed on a release surface from the other mold in the method of the present invention.

FIG. 4 is a schematic view showing a state in which a coating film is formed on a release surface of a molded product locked in one mold in the method of the present invention from the other mold.

FIG. 5 is a schematic view showing a state where a molded product is released from one mold in the method of the present invention, and a coating liquid is sprayed on a mold release surface of the molded product from the one mold.

FIG. 6 is a schematic view showing a state in which a mold is released from one mold in the method of the present invention, and a coating film is formed on a mold release surface of the mold with one mold.

FIG. 7 is a schematic cross-sectional view of a molded product applied by the method of the present invention.

FIG. 8 shows another embodiment of the method of the present invention, in which the molded product is released from one mold and the coating liquid is sprayed on the mold release surface of the one mold. It is a schematic diagram showing.

[Explanation of symbols]

1 Molding machine 2 Fixed type 3 Movable type 5 Hollow type 6 Expandable arm 7 Nozzle chamber 8 Aerosol generator 13 Molded product 14 Coating film 15 Ejector pin 16 Coating film 17 Antistatic film layer

Claims (3)

[Claims] 1. A method of molding a molded article by injecting a raw material between one mold and the other mold, wherein at least one mold is made of a conductor or semiconductor having a large capacitance such as a mold,
When the other mold is released after molding, a suitable coating liquid is sprayed in a state where the molded product is in contact with or close to the one mold to form a coating film made of the coating liquid on the exposed outer peripheral surface of the molded product, Then spray the coating liquid on the remaining outer peripheral surface of the molded product in a state where the molded product is separated from one mold by an ejector pin or the like,
A method for applying a coating liquid such as a surface modifier, which comprises forming a coating film. 2. A method for molding a molded product by injecting a raw material between one mold and the other mold, wherein both molds are made of a conductor or semiconductor having a large electrostatic capacity such as a mold, and after molding. When the other mold is released, an appropriate coating liquid is sprayed with the molded product in contact with or close to one mold to form a coating film of the coating liquid on the exposed outer peripheral surface of the molded product, and then the Separate the molded product from one mold with an ejector pin or the like, and spray the coating liquid on the remaining outer peripheral surface of the molded product while the other mold is closer to the molded product than the one mold to form a coating film. A method of applying a coating liquid such as a surface modifier, which is characterized in that 3. A method for molding a molded product by injecting a raw material between one mold and the other mold, wherein at least one mold is made of a conductor or semiconductor having a large electrostatic capacitance such as a mold,
When the other mold is released after molding, the antistatic agent solution is sprayed while the molded product is in contact with or close to one mold to form a coating film consisting of the antistatic agent on the exposed outer peripheral surface of the molded product. After that, the molded product is sprayed with a solution of the antistatic agent on the remaining outer peripheral surface of the molded product in a state where the molded product is separated from one mold with an ejector pin or the like, and a coating film made of the antistatic agent is formed. And a method for applying a coating liquid such as a surface modifier.