JP7097767B2 - Plasma processing 3D modeling equipment - Google Patents

Description

The present invention relates to a three-dimensional modeling apparatus.

The three-dimensional modeling method includes a material extrusion deposition method in which heat-melted resin is extruded from a nozzle and stacked, and an ultraviolet curable resin composition is sprayed from an inkjet nozzle and irradiated with ultraviolet light to cure it. Inkjet method to deposit, powder sintering method to sinter the powder in the tank by irradiating it with laser light, liquid photocurable resin composition in the tank is irradiated with ultraviolet laser one layer at a time. There are an optical molding method in which layers are laminated while being cured, a powder fixing method in which powder and a binder resin are sprayed simultaneously or alternately to form one layer at a time.
Each method is inadequate in that the resin composition is limited and fine modeling is difficult.

Patent Document 1 describes a method of irradiating the surface of a resin composition for three-dimensional modeling in a constant temperature bath with active energy rays such as ultraviolet rays as a method for producing three-dimensional modeling by a stereolithography method (see paragraph 0079). ).
Since the apparatus used in such a method is limited to the active energy ray-curable resin composition, it is difficult to obtain a molded product having physical properties such as strength as desired, and further, a molded product is obtained. It takes a long time.

Japanese Unexamined Patent Publication No. 2018-53133

It is an object of the present invention to obtain an apparatus that can be cured more reliably by widening the range of the resin composition to be used and the range of physical properties of the obtained molded body as a three-dimensional modeling apparatus using an inkjet method. ..

As a result of diligent studies to solve the above problems, the present inventors have completed the following inventions.
1. 1. An inkjet nozzle for injecting a curable resin composition as a resin composition is provided in the chamber, and the inkjet nozzle can be moved so as to sequentially cure and deposit the curable resin composition ejected from the inkjet nozzle. A plasma processing three-dimensional modeling device in which an atmospheric pressure plasma injection device is installed in the same room as the inkjet nozzle.
2. 2. The atmospheric pressure plasma injection device is a remote type plasma injection device, and the plasma generation source is the plasma processing three-dimensional modeling device according to 1 installed outside the chamber.
3. 3. The plasma processing three-dimensional modeling apparatus according to 1 or 2, wherein the injection port of the atmospheric pressure plasma injection device is not provided toward the inkjet nozzle and the resin composition to be deposited.
4. The plasma processing three-dimensional modeling apparatus according to any one of 1 to 3, wherein the injection port of the atmospheric pressure plasma injection device is provided adjacent to the inkjet nozzle.
5. The plasma processing three-dimensional modeling apparatus according to any one of 1 to 4, wherein one or more injection ports of the atmospheric pressure plasma injection device are provided around the opening of the inkjet nozzle.

According to the apparatus of the present invention, various resin compositions can be adopted without being limited to the active energy ray-curable type when performing three-dimensional modeling using the curable resin composition. At the same time, when an atmospheric pressure plasma is introduced into the tank and brought into contact with the curable resin composition jetted from the inkjet nozzle and deposited to perform curing, the jetted curable resin composition is deposited. It is possible to obtain the effect that the trajectory up to the point is not disturbed and the shape of the once deposited curable resin composition is not disturbed by the air flow.

Schematic diagram of the cross section of the remote type atmospheric pressure plasma generator Diagram of the device according to the present invention The figure of the nozzle part of the apparatus by this invention The figure of the nozzle part of the apparatus by this invention The figure of the nozzle part of the apparatus by this invention

Hereinafter, the apparatus of the present invention will be described in detail.
(Inkjet nozzle)
As the inkjet nozzle in the present invention, the same inkjet nozzle for injecting various known ultraviolet curable resin compositions can be adopted. Further, a known mechanism for moving the inkjet nozzle in the chamber and a system for controlling the movement can be adopted.
The inkjet nozzle is composed of one or more nozzles corresponding to one or more colors. The data for three-dimensional modeling is calculated to obtain an accurate modeling location (location of ink ejection from each nozzle) for each color, and the curable resin composition of each color from each inkjet nozzle can be ejected to this location. The timing of ejection is obtained, and three-dimensional modeling is performed based on the calculation result.
Further, as a base material on which the curable resin composition ejected from the inkjet nozzle is deposited, the cured resin composition can be easily peeled off and can support a three-dimensional model, and surface treatment is required as necessary. It is possible to use a metal plate, a resin plate, a glass plate, or the like.

(Atmospheric pressure plasma injection device)
The atmospheric pressure plasma injection device in the present invention is for curing the curable resin composition ejected and deposited from the inkjet nozzle by atmospheric pressure plasma.
The plasma ejection port of the atmospheric pressure plasma injection device is at least large enough to accommodate the inkjet nozzle and the above-mentioned base material in the chamber, and the plasma generating section and the power supply section are arranged outside the chamber to generate plasma generated remotely. It is to be discharged.
The amount of plasma discharged may be of a known degree, and therefore the chamber needs to be provided with an exhaust port.
When an air flow containing plasma discharged from a plasma ejection port is ejected from an inkjet nozzle and hits a curable resin composition in a non-deposited state, the ejected trajectory may be bent, and as a result, the desired trajectory is desired. It may not be possible to shape the shape.
Further, if the airflow containing plasma is directly applied after the curable resin composition is deposited and before the curing, the deposited state of the uncured curable resin composition may be distorted or deformed.
Therefore, it is desirable that the plasma ejection port is not suitable for the space between the inkjet nozzle and the substrate. Further, it is desirable that the curable resin composition immediately after deposition is not exposed to the air flow containing plasma even before curing.
Therefore, the plasma discharge port can be fixed in the chamber and its direction can be adjusted, or the plasma discharge port can be moved in conjunction with the inkjet nozzle so as to avoid the trajectory in which the curable resin composition flies. ..

In addition, the airflow containing plasma is prevented from directly hitting the curable resin composition, and the base material is, for example, a conductive material such as a metal, and the base material is grounded or the polarity is opposite to the polarity of the plasma. Can be applied to.
As a result, the plasma discharged from the plasma discharge port can be positively irradiated to the curable resin composition, and the curable resin composition can be cured more efficiently.
Further, the amount of plasma in the chamber may be detected and controlled to be the desired amount.

As a plasma generator used for such an atmospheric pressure plasma irradiation curing portion, a remote atmospheric pressure plasma generator can be adopted. Plasma is a gas with high energy, and when a high voltage is applied between the electrodes, an electric discharge is generated. Atmospheric pressure plasma is plasma generated under atmospheric pressure, and is usually used for the purpose of hydrophilizing the surface of a substance.
As such a device, for example, as shown in FIG. 1, a discharge space having an outlet and an electric field in the discharge space are opposed to each other at intervals of about 0.5 to 5.0 mm. A plasma processing device equipped with a discharge electrode is used. In this plasma processing apparatus, the plasma generation gas G is supplied to the discharge space, the pressure in the discharge space is maintained near the atmospheric pressure, and a voltage is further applied to the discharge electrode 31 to start the discharge voltage. When a discharge is generated in the discharge space by exceeding the above, plasma is generated in the discharge space.
Further, the atmospheric pressure plasma used in the present invention includes all gases whose raw material gas is denatured by plasma conversion.

The plasma treatment can be performed by blowing out the gas flow containing the plasma from the outlet and blowing it onto the molded body. Examples of such a plasma processing apparatus include RT series and APT series manufactured by Sekisui Chemical Co., Ltd., and an appropriate plasma processing apparatus provided by Yamato Material Co., Ltd., Japanese Patent Application Laid-Open No. 2004-207145. , The apparatus, nozzle portion, etc. described in JP-A-11-260597 or JP-A-3-2-19082 can also be used.
Further, as the gas used for the atmospheric pressure plasma, air, oxygen, nitrogen or the like can be adopted.
Although the distance between the electrodes is related to the applied voltage, plasma is generated by applying an electric field such as a high frequency, a pulse wave, or a microwave to the electrodes.

Above all, it is preferable to apply a pulse wave in consideration of the fact that the time required for the rise and fall of the electric field (the rise and fall means that the voltage continuously increases or decreases) is preferable. .. The time required for the rise and fall of the electric field at this time is preferably 10 μs or less, and more preferably 50 ns to 5 μs.
The electric field strength generated between the electrodes in the plasma generator is 1 kV / cm or more, preferably 20 kV or more, and / or 1000 kV or less, preferably 300 kV or less.
When an electric field is applied by a pulse wave, the frequency is preferably 0.5 kHz or higher, may be about 10 to 20 MHz, or may be about 50 to 150 MHz.
Further, the electric power between the electrodes is 40 W / cm or less, preferably 30 W / cm or less.

The above electrodes should not be in direct contact with the gas in order to obtain a stable plasma discharge. Therefore, it is necessary to cover the surface of the electrode by coating it with an insulating film by any known means. Examples of such an insulating film include glassy materials such as quartz and alumina, and ceramic materials. Further, depending on the case, a dielectric having a dielectric constant of 2000 or less, such as barium titanate, silicon oxide, aluminum nitride, silicon nitride, and silicon carbide, can be adopted.

Such a remote type atmospheric pressure plasma irradiation curing unit includes, for example, a unit including an atmospheric pressure plasma generating unit, a plasma irradiation nozzle, and a power supply unit among the above-mentioned known devices. Based on this device, in order to uniformly process the substrate to be printed matter in the width direction, a plurality of parts for injecting atmospheric pressure plasma are arranged in the width direction, or the shape of the nozzle is slit-shaped. And so on.
A schematic cross-sectional view of such a remote atmospheric pressure plasma generating portion is shown in FIG. In FIG. 1, one of them is grounded, and a gas to be plasmatized passes between a pair of electrodes 31 having a layer formed of an insulator 32 or the like on the surface, and the voltage applied between the electrodes at the time of passing through the pair of electrodes 31. The gas is turned into plasma. In FIG. 1, the airflow including the atmospheric pressure plasma P is provided so as to directly hit the surface of the substrate S to be printed, but the atmospheric pressure plasma may not be directly applied.

FIG. 2 shows an example of the plasma three-dimensional modeling apparatus of the present invention. A nozzle portion 2 of an inkjet nozzle for ejecting resin is provided in the chamber 1. As the structure of the nozzle portion 2, a nozzle used in a conventional three-dimensional modeling apparatus by an inkjet method can be adopted.
The nozzle portion 2 can move in the x-direction and the y-direction parallel to the surface of the base material 4 for molding the molded body, or in the composite direction thereof, and the z in the vertical direction of the base material 4 as the molded body 5 is molded. It can also be moved in the direction. In FIG. 2, the molded body 5 is in the middle of molding, and becomes a target molded product as the nozzle portion 2 moves.
In FIG. 2, a plasma introduction tube 3 is provided so that an air flow containing plasma can be introduced from three directions toward the inside of the chamber 1. The plasma introduction tube 3 has a known structure and material, and is for introducing an air flow containing plasma generated in a known atmospheric pressure plasma generating portion (not shown) into the chamber.

In FIG. 2, a total of three plasma introduction tubes 3 are installed in three directions, but the number, position, and direction thereof can be arbitrarily determined. What is required is that the airflow containing the plasma does not disturb the trajectory of the resin discharged from the nozzle portion 2, and that the plasma necessary for rapidly curing the resin after the discharge is introduced. Therefore, it is desirable that the injection port of the plasma introduction tube 3 of the atmospheric pressure plasma injection device is not provided toward the inkjet nozzle and the resin composition to be deposited.

It is necessary to provide the chamber 1 with a discharge port for discharging the atmosphere outside the chamber 1 as much as the air flow containing plasma is introduced, and the resin discharged from the nozzle portion 2 depending on the atmosphere discharged from the discharge port. It is necessary that the orbit of the chamber is not disturbed, the atmosphere of the part containing high-concentration plasma is not discharged as much as possible, and ozone and the like existing in the atmosphere can be removed or components to be treated can be reliably removed or treated. It is necessary to.
Further, a cover 6 for covering the nozzle portion 2 and the plasma introduction tube (not shown) can be provided. By providing this cover, it is possible to prevent the irradiated atmospheric pressure plasma from being diffused, and it is possible to further increase the atmospheric pressure plasma density in the cover 6.
Further, when such a cover is provided, it is possible to increase the plasma density in the atmosphere inside the cover 6 and to not directly apply the air flow having the atmospheric pressure plasma P to the uncured resin. It will be easier.
Further, the tip of the nozzle portion 2 is directed upward, and the air flow having the atmospheric pressure plasma P ejected from the tip can be retained in the cover 6, thereby further improving the plasma density in the cover 6. Becomes easier.

FIG. 3 is an enlarged view of an example of the nozzle portion 2, in which a nozzle 11 for discharging resin and electrodes 12 are provided on both sides thereof. The electrode 12 may be grounded or may be charged on the positive electrode or the negative electrode.
As shown in the figure, the electrodes 12 may be provided on both sides of the nozzle 11, but either one of them may be provided, and the electrodes 12 may be provided so as to surround the nozzle 11.
The electrode 12 is provided to increase the plasma density in the vicinity of the electrode 12. Therefore, other parts may be covered with an insulating material so that only the tip of the electrode 12 is exposed. Further, since the resin discharged from the nozzle 11 is provided to be cured quickly, it is preferable that the tip of the electrode 12 is closer to the base material than the tip of the nozzle 11.

The structure of the electrode 12 may be as shown in FIG. The electrodes 12 around the nozzle 11 are reticulated and may be coated with an insulator in some cases. Another electrode 13 may be connected to the tip of the electrode 12. The electrode 13 is donut-shaped, and a hole through which the resin discharged from the nozzle 11 passes is formed in the center thereof, and the periphery thereof is a plate-shaped or net-shaped electrode. With such a shape, the air resistance when the nozzle portion 2 moves is reduced. Therefore, the turbulent flow generated by the movement of the nozzle portion 2 can be made smaller. As a result, the resin discharged from the tip of the nozzle 11 is accurately laminated.

The nozzle portion 2 is adjacent to the nozzle 11 as shown in FIG. 5 after the plasma introduction tube 3 is provided as shown in FIG. 2 or instead of the plasma introduction tube 3 being fixedly provided in FIG. It is possible to provide one or more plasma introduction tubes. At this time, it is necessary to adjust the speed of the airflow ejected from the tip of the plasma introduction tube 3 so as not to disturb the trajectory of the resin discharged from the tip of the nozzle 11. According to this structure, the resin discharged from the nozzle 11 can be quickly cured.

1 ... Chamber 2 ... Nozzle part 3 ... Plasma introduction tube 4 ... Base material 5 ... Molded body 11 ... Nozzle 12 ... Electrode 13 ... Electrode 31 ... Electrode 32 ... Insulator G ... Plasma generation gas P ... Atmospheric pressure plasma S ... Printed substrate

Claims (5)

An inkjet nozzle for injecting a curable resin composition as a resin composition is provided in the chamber, and an atmospheric pressure plasma injection device is further provided so that the curable resin composition ejected from the inkjet nozzle is sequentially cured and deposited. A plasma processing three-dimensional modeling device in which an inkjet nozzle can be moved and a plasma introduction tube is provided adjacent to the inkjet nozzle. The plasma processing three-dimensional modeling apparatus according to claim 1, wherein the atmospheric pressure plasma injection device is a remote type plasma injection device, and the plasma generation source is installed outside the chamber. The plasma processing three-dimensional modeling apparatus according to claim 1 or 2, wherein the discharge port of the atmospheric pressure plasma injection device is not provided toward the inkjet nozzle and the resin composition to be deposited. The plasma processing three-dimensional modeling apparatus according to any one of claims 1 to 3, wherein the discharge port of the atmospheric pressure plasma injection device is provided adjacent to the inkjet nozzle. The plasma processing three-dimensional modeling apparatus according to any one of claims 1 to 4, wherein one or more ejection ports of the atmospheric pressure plasma injection device are provided around the opening of the inkjet nozzle.

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