JP2011011177A - Tumbler coating apparatus and tumbler coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tumbler coating apparatus or the like which is capable of preventing the adhesion of objects to be treated with each other and thinly and uniformly covering the components to be covered.SOLUTION: The tumbler coating apparatus or the like is provided with a rotation means which has a storing space and rotates around the rotation shaft inclined with a predetermined angle to the horizontal direction, a storing means which rotates with the rotation means in a state that a number of the objects to be treated are stored inside and which is formed by a reticular material, has a tubular part and a bottom part, and is fitted to the storing space so that the center of the bottom part coincides with the rotation shaft, a spraying means to spray a covering treatment liquid towards a number of the objects to be treated flowing within the storing means and a heating means to solidify the components to be covered that are attached on the surface of a number of the objects to be treated by heating a number of the objects to be treated flowing within the storing means. Also the apparatus has a constitution that a protrusion protruding to the upper side of the rotation shaft is installed at the bottom of the storing means and that a number of the objects to be treated are fluidized between the protrusion and the tube part.

Description

  The present invention relates to a tumbler coating apparatus and a tumbler coating method, and in particular, a uniform thickness is formed on the surface of each workpiece by adhering and solidifying a coating treatment liquid while flowing a large number of workpieces. The present invention relates to a tumbler coating apparatus and a tumbler coating method for forming a coating film having a coating component.

Conventionally, an insulating coating is formed on the surface of a magnetic core used in various electrical components in order to ensure electrical insulation.
Thus, a coated ferrite molded product in which the surface of the ferrite molded product is coated with a film containing a polyimide resin and a method for manufacturing the same have been proposed (for example, see Patent Document 1).
Then, as a method of forming a thin film on the object to be processed such as a molded product, as shown in FIGS. 6A to 6B, while using the tumbler coating apparatus 100, 200, while rotating the object to be processed, A method of forming a film in which a coating treatment agent is attached and solidified is disclosed.

More specifically, in the case of the tumbler coating apparatus 100 shown in FIG. 6A, the internal space 120 includes stirring control plates 107a and 107b for a plurality of objects to be processed, and a transport control apparatus 105. The rotating member 113 can be rotated in a predetermined rotation direction by the rotating device 111 under the connecting portion 109.
In the case of the tumbler coating apparatus 200 shown in FIG. 6B, the tumbler coater 200 has an inner space 220 and a rotating member 213 with an openable / closable door 203, and the inner space 220 has a plurality of stirrings. The baffles 207a and 207b and the transport baffle 205 may be provided, and the rotating member 213 may be rotated by the rotating device 211 on the side surface of the communication unit 209.
Therefore, according to these tumbler coating apparatuses 100 and 200, the rotation means 113 and 213 having the internal spaces 120 and 220 are provided, and the rotation means 113 and 213 are provided in a state where a ferrite molded product (not shown) is accommodated. It is described that the coating treatment agent can be efficiently attached to the entire surface of the ferrite molded product while rotating and vibrating by rotating.

Japanese Patent No. 3865765 (claims, etc.)

However, in the conventional tumbler coating apparatus shown in Patent Document 1, the bottom portion of the accommodation space is basically a flat bottom or a flat or curved surface with an inclined surface, and the processing amount of an object to be processed increases, When the shape of the processed object was reduced in size, a phenomenon that the objects to be processed were easily adhered to each other was observed.
In addition, when a relatively thin film was formed, there was a phenomenon that the amount of the coating treatment agent varied easily on the surface of each object to be processed, and it was not easy to form a uniform thickness.

In view of the fact that the inventors of the present invention have intensively studied and the fact that the shape of the accommodation space can affect the state of film formation on the object to be processed, by making it a predetermined form, Regardless of the size, the objects to be processed were not adhered to each other, and for example, even a coating made of a thin film of 10 μm or less was found to be capable of forming a film uniformly and stably, and the present invention was completed. Is.
That is, the present invention effectively prevents the objects to be treated from adhering to each other, and can efficiently form even a thin film having a uniform thickness as a coating on a large number of small objects to be processed. It is an object to provide a tumbler coating apparatus capable of forming a film and a tumbler coating method using such a coating apparatus.

  According to the present invention, the rotating means that has an accommodation space and rotates around a rotation axis inclined at a predetermined angle with respect to the horizontal direction and the net-like material has a cylindrical portion and a bottom portion. An accommodation unit that is mounted in the accommodation space so that the center portion is arranged to coincide with the rotation axis, and that rotates together with the rotation unit in a state where a large number of objects to be processed are accommodated therein, A spraying means for spraying a coating treatment liquid containing a coating component for coating the surface toward a large number of objects to be processed flowing in the storage means, and heating a large number of objects to be processed flowing in the storage means. And a heating means for solidifying the coating component adhering to the surface of a large number of objects to be processed, and a protrusion projecting upward of the rotating shaft is provided at the center of the bottom of the storage means. , Configured to allow a large number of workpieces to flow between the cylinder Tumbler coating apparatus is provided, characterized in Rukoto, it is possible to solve the problems described above.

That is, according to the tumbler coating apparatus of the present invention, the tumbler coating apparatus includes the accommodating means for causing a large number of objects to be treated to flow by using gravity or the like by rotating while tilting together with the predetermined rotating means. Since a large number of objects to be processed flow between the protrusion and the cylindrical part, a large number of objects to be processed can be stirred efficiently and gently using the avalanche phenomenon. Can do.
Accordingly, the coating treatment liquid is sprayed onto the surface of a large number of objects to be processed by spraying the coating treatment liquid toward a large number of objects to be processed flowing in the storage means by the spraying means. Can be made.
In addition, by directly or indirectly heating a large number of objects to be processed flowing in the storage means by a predetermined heating means, the coating component adhering to the surface can be uniformly and rapidly solidified. It is possible to effectively prevent the processed products from being adhesively bonded to each other via the coating component.
Therefore, the present invention provides a tumbler coating apparatus capable of efficiently forming a thin film having a uniform thickness as a coating on a large number of small-sized objects to be processed as well as small and large-sized objects. be able to.

Further, in configuring the tumbler coating apparatus of the present invention, the heating means includes a heated gas ejection portion that ejects heated gas, and together with the heated gas, the coating treatment liquid is applied to a large number of objects to be processed. It is preferable to spray.
By comprising in this way, solidification of the coating component contained in the coating process liquid adhering to many to-be-processed objects can be accelerated | stimulated using the temperature and airflow of heating gas.

Moreover, when comprising the tumbler coating apparatus of this invention, it is preferable that a heating means is further equipped with the heater which can heat the inside of accommodation space by heating a rotation means.
By comprising in this way, it becomes easy to keep the inside of the accommodation space at a temperature at which the coating component of the coating treatment liquid can be solidified. Therefore, even when a large number of objects to be processed are flowed in the storage means, the ambient temperature in contact with the surface of each object to be processed is stabilized, and the coating components of the coating processing liquid adhering to the objects to be processed can be quickly And can be solidified uniformly.

Further, in configuring the tumbler coating apparatus of the present invention, the rotating means has a side peripheral wall and a bottom wall surrounding the accommodation space, and the bottom wall and the protrusion are spaced apart so as to allow ventilation. Is preferred.
By comprising in this way, the airflow at the time of spraying a coating processing liquid can permeate | transmit along the inside or surface of the protrusion of the bottom part of a storage means, and many coating processing liquids which exist in an airflow can be processed It can be more efficiently attached to an object.

Further, in constituting the tumbler coating apparatus of the present invention, the coating treatment liquid is a solution containing a polyimide resin precursor or a polyimide resin composition as a coating component, and the coating component can be cured by heating means. It is preferable to heat the workpiece.
By comprising in this way, it becomes easy to ensure the intensity | strength of a coating component, while making a coating processing liquid adhere sequentially to many to-be-processed objects. Therefore, the coating film is hardly damaged during the coating treatment liquid spraying process, and it becomes easier to form a coating film having a uniform thickness more reliably.

  According to another aspect of the present invention, there is provided a tumbler coating method in which a coating component is coated on the surface of a large number of objects to be processed using the tumbler coating apparatus according to any one of the above, and the large number of objects to be processed. The tumbler coating method is characterized by simultaneously spraying the coating treatment liquid from the spraying means and solidifying the coating component by heating of the heating means while flowing at the bottom of the containing means. Can be solved.

  That is, according to the tumbler coating method of the present invention, using the tumbler coating apparatus described above, while spraying a large number of objects to be processed at the bottom of the storage means, spraying the coating treatment liquid from the spraying means, and heating means Since the coating component is solidified by heating at the same time, the coating treatment liquid can be uniformly adhered to a large number of objects to be processed, and adhesion between the objects to be processed can be prevented and solidified uniformly. . Therefore, a coating component can be coated thinly and uniformly on a large number of objects to be processed while preventing the objects to be processed from being bonded to each other.

Moreover, when implementing the tumbler coating method of this invention, it is preferable to make the thickness of the film in the surface of a to-be-processed value into the value within the range of 0.1-10 micrometers.
By carrying out in this way, it is possible to more efficiently obtain an object to be processed having a thin film coating within a predetermined time, and as a result, it is possible to effectively prevent thermal alteration and the like in the object to be processed. .
Moreover, even if it is such thickness, since it is uniform and homogeneous, the predetermined durability and electrical insulation as a film can be ensured.

Further, in carrying out the tumbler coating method of the present invention, the surface of a large number of objects to be treated is preferably made of metal, and it is preferable to spray a coating treatment liquid after spraying alumina particles onto the large number of objects to be treated and sandblasting.
By carrying out in this way, even when an oxide film or the like is provided on the surface of the object to be processed, it can be removed efficiently, so that a thinner and uniform film can be stably formed. Can be formed.
In addition, since the oxide film is removed, adverse effects on the electrical characteristics and magnetism of the object to be processed due to the oxide film can be eliminated.

FIG. 1 is a schematic diagram for explaining a tumbler coating apparatus according to the present invention. FIGS. 2A to 2C are schematic views provided to explain the rotating means, the accommodating means, and the combination thereof in the present invention. FIG. 3 is a diagram for explaining the relationship between the height (H2) of the protrusion with respect to the height (H1) of the housing means, and the like. FIG. 4 is a perspective view provided for explaining an object to be processed for forming a coating film in the present invention. FIG. 5 is a schematic diagram for explaining the sanding blasting apparatus used in the present invention. 6 (a) to 6 (b) are schematic views for explaining a conventional tumbler coating apparatus.

[First Embodiment]
As illustrated in FIGS. 1 and 2, the first embodiment is
A rotating means 27 having a storage space 25 and rotating around a rotation axis (L) inclined at a predetermined angle with respect to the horizontal direction;
It is formed of a net-like material, has a cylindrical portion 29a and a bottom portion 29b, and is attached to the accommodating space 25 so that the center portion of the bottom portion 29b is aligned with the rotation axis (L). Storage means 29 that rotates together with the rotation means 27 in a state where the
Spraying means 31 for spraying a coating treatment liquid 31a containing a coating component toward a large number of objects to be processed flowing inside the storage means 29;
Heating means 35 for heating a large number of objects to be processed flowing inside the accommodating means 29 and solidifying the coating components adhering to the surfaces of the large number of objects to be processed;
The bottom 29b of the accommodating means 29 is provided with a protrusion 29e protruding upward from the rotation shaft (L), and a large number of objects to be processed are allowed to flow between the protrusion 29e and the cylindrical portion 29a. The tumbler coating apparatus 20.

That is, the tumbler coating apparatus sprays and attaches the coating treatment liquid while allowing a large number of treatment objects to flow in a predetermined place, and solidifies the coating components in the coating treatment liquid on the surface of each treatment object. Thus, the apparatus forms a uniform and thin film on the entire surface of the object to be processed.
Note that the flow of a large number of objects to be processed means that they rotate and move to a predetermined position in the same direction with respect to a portion that holds a large number of objects to be processed while changing the orientation or relative position of each object to be processed. Furthermore, it may include an operation of returning to the initial position at a predetermined position.
Embodiments relating to a tumbler coating apparatus will be specifically described below with reference to the drawings as appropriate.

1. As shown in FIG. 4, the object to be processed may be a member having a shape and size capable of flowing, and may be a deformed shape having irregularities on the surface or a shape having recessed corners. .
The workpiece 10 of this embodiment is a magnetic core member having a substantially U shape as shown in FIG. 4 and has a recessed corner 11.
A typical example of such an object to be processed 10 is a magnetic core made of a soft magnetic material whose coercive force easily changes at 400K to 800K, for example.
More specifically, Fe-Si-Al-based powder, composite soft magnetic powder composed of this Fe-Si-Al-based powder and an insulating binder, and the like can be mentioned.
Further, since the core loss is small, the size can be reduced, and the use at high frequency becomes possible, it is preferable that the holding force of the object to be processed is 3 Oe (= 79.4 A / m) or less. More preferably, the value is in the range of 1 to 1 Oe.

2. Coating treatment liquid The coating treatment liquid 31a shown in FIG. 1 contains a coating component for forming a coating on the surface of the object to be processed, and after attaching the coating component to the surface of the object to be processed, By solidifying, it is a liquid material that can form a predetermined film on the surface of the object to be processed.
Such a coating treatment liquid includes, as a coating component, for example, a polyimide resin precursor such as polyamic acid, a polyimide resin, and one or more curing components that can be polymerized with a polyimide resin such as an epoxy compound or an epoxy resin. It is the solution or dispersion liquid containing the polyimide resin composition containing these.
That is, when these coating components are solidified, a film made of polyimide resin, epoxy resin, or the like can be formed, and a film having a thickness of, for example, 0.1 to 10 μm is formed on the surface of the object to be processed. can do.

Examples of the solvent or dispersion medium for dissolving or dispersing the coating component include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, Examples include polar solvents such as N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), phenol, cresol, xinol, halogenated phenol, catechol, hexamethylphosphoramide, γ-butyrolactone (GBL), and tetrahydrofuran.
That is, with these solvents or dispersion media, the coating component can be uniformly dissolved or dispersed.
Moreover, since evaporation is comparatively easy, when the tumbler coating apparatus of this invention is used, it can dry and harden efficiently, without the some to-be-processed object connecting and adhering.

3. Coating The thickness of the coating on the surface of the object to be treated depends on the type and form of the adherend, and also on the form of the coating treatment liquid. For example, the thickness of the coating is in the range of 0.1 to 10 μm. It is preferable to set the value within the range.
The reason for this is that when the thickness of the coating is less than 0.1 μm, when the form of the adherend is reduced in size, it becomes difficult to form stably, the electrical insulation is significantly reduced, This is because the type of coating treatment liquid that can be used may be excessively limited.
On the other hand, if the thickness of the coating exceeds 10 μm, the type of adherend that can be applied may be excessively limited.
Therefore, the thickness of the coating is more preferably set to a value within the range of 1 to 9 μm, and more preferably set to a value within the range of 3 to 8 μm.

In forming such a film, it is preferable to use a liquid material having a high mixing ratio of the solvent or the dispersion medium with respect to the coating component as the coating treatment liquid.
More specifically, the concentration of the solvent or dispersion medium in the coating treatment liquid is preferably a dilute liquid of 5 to 50% by weight, for example, 10 to 35% by weight with respect to the total amount of the coating treatment liquid. A value within the range is more preferred, and a value within the range of 15 to 25% by weight is even more preferred.

And in forming such a film, it is preferable to make the viscosity (measuring temperature: 25 degreeC, the following is the same) of a coating processing liquid normally into the value within the range of 10-10000 mPa * sec.
The reason for this is that if the coating treatment liquid has such a viscosity, it is easy to uniformly attach fine droplets to the object to be treated by spraying.
That is, if the viscosity of the coating treatment liquid is less than 10 mPa · sec, it may be difficult to form a coating having a uniform thickness as a whole due to the surface tension.
On the other hand, when the viscosity of the coating treatment liquid exceeds 10,000 mPa · sec, it may be difficult to spray uniformly, or adjacent workpieces may be easily bonded to each other.
Therefore, the viscosity of the coating treatment liquid is more preferably set to a value within the range of 50 to 5000 mPa · sec, and further preferably set to a value within the range of 100 to 1000 mPa · sec.

Furthermore, when forming such a coating film, it is preferable that the amount of the coating treatment liquid be set to a value within the range of 0.0001 to 10 ml per 100 cm ² of the surface area of the workpiece.
The reason for this is that if the amount of the coating treatment liquid is less than 0.0001 ml per predetermined surface area, excessive processing time may be required to obtain a predetermined film thickness.
On the other hand, when the processing amount of the coating treatment liquid exceeds 10 ml per predetermined surface area, it may be difficult to spray uniformly, or adjacent workpieces may be easily bonded. It is.
Therefore, the treatment amount of the coating treatment liquid is more preferably set to a value in the range of 0.001 to 1 ml, and a value in the range of 0.01 to 0.1 ml per 100 cm ² of the surface area of the workpiece. More preferably.

4). Tumbler Coating Apparatus (1) Basic Configuration A tumbler coating apparatus 20 illustrated in FIG. 1 basically includes a bottom portion 27b and a rotating means 27. Of these, the rotating means 27 is horizontally supported by a support portion 21. The rotating unit 27a is supported by being inclined at a predetermined angle with respect to the direction, and the accommodating space 25 is provided inside the rotating unit 27. The rotating unit 27 is inclined by a rotation driving unit 23 such as a motor. It is configured as a rotating drum or the like that can rotate around the rotating shaft (L).

The tumbler coating apparatus 20 accommodates, for example, a net drum or the like that is detachably mounted in the accommodating space 25 of the rotating means 27 in a state where a large number of objects 10 having the shape shown in FIG. 4 are accommodated. Means 29 are provided.
Further, spray means 31 such as a spray gun capable of spraying the coating treatment liquid 31 a is provided inside the storage means 29 of the storage space 25.
Further, a heater (not shown) as a part of the heating means 35 provided inside the rotating portion 27 a in the rotating means 27 and the accommodating means 29 in the accommodating space 25 provided in the vicinity of the blowing means 31. Another heating means 35 capable of ejecting heated gas is provided inside.

(2) Rotating means The rotating means 27 of the tumbler coating apparatus 20 includes a bottom portion 27b, a rotating portion 27a, and a rotation driving portion 23. The accommodation space 25 is surrounded by these and has an upper portion opened. Is provided.
The rotating means 27 is driven around a rotation axis (L) inclined at a predetermined angle with respect to the horizontal direction by being driven at a predetermined rotation speed by a rotation driving unit 23 such as a motor connected to the rotation unit 27a. It is configured to be rotatable.

Further, in the mounted state, the rotation means 27 is rotated by the rotation drive unit 23, whereby the accommodation means 29 is rotated, whereby a large number of objects 10 having the shape shown in FIG. It moves with rotation while being held in a predetermined space formed by 29 cylindrical portions 29a and projections 29e, and further by a bottom portion 29b (flat bottom surface portion 29g).
At this time, a so-called avalanche phenomenon is repeatedly generated in a predetermined space, and the workpiece 10 is repeatedly raised and lowered by gravity on the rear side in the rotation direction, and stably flows in the housing means 29. Is configured to do.

In the tumbler coating apparatus 20, the rotating means 27 and the accommodating means 29 are arranged as follows in order to efficiently and gently stir the object 10 by regular flow of the object 10 inside the accommodating means 29. It is configured as follows.
First, the inclination angle of the rotation axis (L) is increased around the rotation axis (L), so that a large number of workpieces 10 can be appropriately raised in the rotation direction inside the accommodating means 29, and also due to gravity. The angle is set so that it can be lowered.

The inclination angle is selected according to various conditions such as the aspect of the workpiece 10, the aspect of the containing means 29, the rotation speed, and the like. For example, the value is within a range of 30 to 80 ° with respect to the horizontal direction. It is preferable that
This is because if the inclination angle of the rotation axis (L) with respect to the horizontal direction is excessively small, it becomes difficult for the portion to be processed to move from the lowermost portion of the storage means 29, and the object to be processed 10 is stable inside the storage means 29. This is because it may be difficult to flow.
On the other hand, when the inclination angle of the rotation axis (L) with respect to the horizontal direction is excessively large, it becomes easy to rotate together with the rotation unit 27 and the storage unit 29 while the workpiece 10 remains on the bottom 29b of the storage unit 29. Because there is.
Therefore, the inclination angle of the rotation axis (L) is more preferably set to a value within the range of 45 to 75 °, and further preferably set to a value within the range of 50 to 70 ° with respect to the horizontal direction.
Note that it is preferable that the inclination angle of the rotation shaft (L) be adjustable by adjusting the attachment angle of the rotating portion 27a with respect to the support portion 21, for example.

Next, the rotation speed of the rotation means 27 is set to a speed at which a large number of objects to be processed 10 can move moderately with the rotation of the rotation means 27 and the storage means 29 due to friction with the storage means 29 or the like.
Therefore, it is preferable to set the rotation speed of the rotation means 27 to a value within the range of 2 to 25 rpm, for example.
That is, if the rotational speed is excessively high, the frictional force between the accommodating means 29 and the object to be processed 10 becomes large, or the centrifugal force acts to increase the amount of increase, so that the impact at the time of lowering is likely to increase. This is because the film may be easily damaged.
On the other hand, if the rotational speed is excessively low, the amount of the coating treatment liquid adhering to the object to be processed 10 at a time may be increased, and it may be difficult to uniformly adhere.
Therefore, the rotational speed of the rotating means 27 is more preferably set to a value within the range of 2 to 15 rpm, and further preferably set to a value within the range of 4 to 10 rpm.

(3) Accommodating means As shown in FIGS. 1 to 3, the accommodating means 29 has a cylindrical portion 29a and a bottom portion 29b, and accommodates the center portion of the bottom portion 29b so as to coincide with the rotation axis (L). It is a member that is mounted in the space 25 and rotates together with the rotation means 27 in a state in which a large number of objects 10 are accommodated therein.
That is, the accommodating means 29 shown in FIG. 2 (b) is used by being mounted in the accommodating space 25 of the rotating means 27 as shown in FIG. 2 (c). Therefore, the rotating means 27 shown in FIG. 2 (a) is used. It has a cylindrical tube portion 29a and a bottom portion 29b so that it can be accommodated in the storage space 25, and is formed in a container shape with an open top.

Here, as shown in FIG. 2B, the accommodating means 29 is formed of a mesh material having a large number of openings through which the workpiece 10 cannot pass.
As such a net-like material, for example, a slenless net having a value within a range of 30 to 80 mesh can be exemplified.
The reason for this is that by using such a net-like material, when the object to be processed 10 is stored in the container means 29 and rotated with the rotating means 27 while being inclined, the material is held inside the container means 29. This is because a large number of objects to be processed 10 can be easily moved with an appropriate sliding resistance by rotation of the accommodating means 29, and good air permeability can be easily obtained.

As shown in FIG. 2B, a conical or frustoconical protrusion 29e is provided on the bottom 29b of the accommodating means 29 so as to protrude upward from the rotation shaft (L).
In addition, in the bottom 29b of the accommodating means 29, a substantially flat bottom surface portion 29g is provided in a circle shape between the peripheral portion and the protrusion 29e.
Further, as shown in FIG. 3, a predetermined flange 29c is provided in the upper part of the accommodating means 29, and is configured so that it can be bent outward or inward.
Therefore, as shown in FIG. 2 (c), the accommodating means 29 enters the accommodating space 25 from the opening at the top of the rotating means 27 shown in FIG. By being mounted, it can be rotated together with the rotating means 27.
Further, since the flange 29c of the housing means 29 comes into contact with the distal end portion 27c and the flange 27d of the rotating means 27, even when rotated together with the rotating means 27, it is in a mounting state that is difficult to come off.

That is, in such a mounted state, the center portion of the bottom portion 29b of the accommodating means 29 is arranged so as to coincide with the rotation axis (L). Further, since the wall of the cylindrical portion 29a of the rotating means 27 exists, a predetermined space having a V-shaped cross section is formed between the cylindrical portion 29a and the protruding portion 29e.
Therefore, regular flow of the object to be processed 10 is likely to occur in the predetermined space, and the object to be processed 10 can be efficiently and gently stirred. As a result, a large number of fluids flowing in the accommodating means by the spraying means can be obtained. By spraying the coating treatment liquid toward the object to be treated, the coating treatment liquid can be adhered thinly and uniformly to the surfaces of a large number of objects to be treated.

Further, in the accommodating means 29 shown in FIG. 3, the ratio H2 / H1 of the height (H2) of the protruding portion 29e to the height (H1) of the cylindrical portion 29a with respect to the height (H2) of the protruding portion 29e of the accommodating means 29. As for, it is preferable to set it as the value within the range of 1-5.
The reason for this is that when the ratio H2 / H1 is less than 1, the distance between the cylindrical portion 29a of the accommodating means 29 and the protrusion 29e, in particular, the upper interval tends to be narrowed. This is because the object to be processed 10 that flows in a predetermined space formed between the protrusion 29e is difficult to spread during the flow, and the coating treatment liquid may not be uniformly attached.
On the other hand, when the ratio H2 / H1 exceeds 5, the height of the protrusion 29e becomes excessively low, and when the inclination angle is excessively small, a large number of objects to be processed 10 spread in the width direction. This is because it may be difficult to flow, and it may be difficult to uniformly apply the coating treatment liquid.
Therefore, it is more preferable that the ratio H2 / H1 is set to a value within the range of 1.5 to 7, and a value within the range of 1.5 to 5 with respect to the height of the protrusion 29e of the accommodating means 29. Further preferred.

Moreover, in the accommodating means 29 shown in FIG. 3, regarding the height (H2) of the protrusion 29e of the accommodating means 29, it is usually preferable to set the value within a range of 20 to 100 mm.
The reason for this is that when the height (H2) of the protrusion 29e is less than 20 mm, it is difficult to stably form the clothing treatment liquid on the object to be treated, and the rotation axis is inclined. This is because when the angle is excessively large, a large number of objects to be processed 10 are likely to spread in the width direction, and it may be difficult to uniformly apply the coating treatment liquid.
On the other hand, when the height (H2) of the protrusion 29e exceeds 100 mm, it may be more difficult to stably form the clothing treatment liquid on the workpiece. In addition, when the inclination angle of the rotation shaft is excessively small, the interval between the cylindrical portion 29a of the accommodating means 29 and the protrusion 29e tends to be narrow, and the object to be processed 10 that flows in the predetermined space spreads when flowing. This is because the coating treatment liquid may become difficult to adhere uniformly to the object to be processed.
Therefore, the height (H2) of the protrusion 29e of the accommodating means 29 is more preferably set to a value within the range of 30 to 90 mm, and further preferably set to a value within the range of 40 to 80 mm.

As shown in FIG. 2 (b), the protrusion 29e of the accommodating means 29 cuts a part of the flat plate-like net-like material, shifts the cut parts and overlaps them, and welds or sews them together. By providing the portion 29f, it can be easily formed.
In addition, the cylindrical portion 29a of the accommodating means 29 has a function as a reinforcing portion 29d by laminating a plurality of flat plate-like reticulated materials and welding or sewing them, and has a predetermined durability superior in durability. It can be set as the shape cylinder part and the accommodating means 29 containing it.
At that time, as shown in FIG. 2 (b), a number of objects to be processed are formed by forming a welded or sewn portion as a reinforcing portion 29d having irregularities of about 0.1 to 2 mm on the inner surface of the cylindrical portion 29a. The frictional force between the object and the object can be improved, and the object to be processed can flow more stably.

(4) Spraying unit Further, the spraying unit 31 of the tumbler coating apparatus 20 includes the rotating unit 27 and the storing unit so as to spray the coating treatment liquid 31a toward a large number of objects to be processed 10 flowing inside the storing unit 29. From the opening side of the upper part of 29, it arrange | positions inside the accommodating means 29 so that the discharge outlet as a front-end | tip part may face.
It is preferable that the discharge port of the spraying means 31 be oriented between the bottom 29b and the projecting portion 29e of the bottom portion 29b and the cylindrical portion 29a, from the lowest end in the rotation direction to ¼ rotation rear. The reason for this is that the coating treatment liquid 31a is easily attached to a large number of fluidized objects 10 to be treated.

The spraying means 31 is configured to spray the coating treatment liquid 31a from the storage tank 48 into fine droplets and spray it onto a large number of objects to be treated 10 by compressed air supplied from a compressed air supply source 49. Yes.
Although the spraying pressure and the spraying amount can be appropriately selected according to the type and form of the appropriate workpiece 10, for example, when the distance from the discharge port of the spraying means 31 to the workpiece 10 is 30 cm or less. The pressure of the blowing gas is preferably set to a value within the range of 0.1 to 0.3 MPa.
And it is preferable to make the spraying amount of a coating processing liquid into the value within the range of 0.5-2 ml / min, for example, and it is further more preferable to set it as the value within the range of 0.8-1.5 ml / min. .

(5) Heating unit Further, the tumbler coating apparatus 20 includes, as the heating unit 35, a heater (not shown) provided in the rotating unit 27, and a heated gas ejection unit 35 provided in the vicinity of the spraying unit 31, It has.
Such a heater is supplied with power and heats the rotating means 27 to a predetermined temperature. For example, the temperature of the inner surface of the rotating means 27 can be heated to a temperature of 50 ± 20 ° C.

Moreover, the heated gas ejection part 35 sprays the heated gas toward many processed objects 10 that flow in the accommodating part, and is configured to eject a heated gas having a temperature of, for example, 250 ± 20 ° C. Yes.
These heaters and heated gas jetting portions 35 can be heated to a temperature at which the coating components adhering to a large number of objects to be processed 10 flowing in the housing portion can be solidified. Here, it is possible to raise the temperature to at least a temperature at which the solvent of the coating treatment solution can be sufficiently evaporated, and it is preferable that the temperature can be raised to a temperature at which the polyimide resin precursor or the polyimide resin composition can be subjected to condensation polymerization.

(6) Operation A large number of objects 10 whose surfaces have been cleaned in this way are accommodated in the accommodating means 29 of the tumbler coating apparatus 20, and the accommodating means 29 is rotated by the rotating means 27. The rotation means 27 is rotated at a predetermined speed by a rotation drive unit 23 such as a motor or a V belt.
Thereby, inside the accommodating means 29, a large number of objects to be processed 10 rise from the lowermost part in the rotation direction, and a large number of objects to be processed 10 descend by gravity, and these continue, A large number of objects to be processed 10 flow inside the accommodating means 29.
In addition, the rotating means 27 is heated to a predetermined temperature by a heater, and a heated gas at a predetermined temperature is ejected from the heated gas ejection portion 35 toward a large number of objects to be processed 10 to heat the numerous objects to be processed 10. To do.

In this state, the coating treatment liquid 31a is sprayed from the spraying means 31 toward a large number of objects to be processed 10 to mainly adhere the coating components to the surface.
Thereby, spraying of the coating treatment liquid 31 a from the spraying means 31 and solidification of the coating component by heating of the heating means 35 are simultaneously performed while flowing a large number of objects to be processed 10 inside the storage means 29. Then, the solvent evaporates from the coating treatment liquid 31a adhering to the surface of the workpiece 10 and the coating components contained in the coating treatment liquid 31a are solidified.

In addition, while performing such spraying, the gas sprayed from the spraying means 31 and the gas sprayed from the heated gas spraying part 35 do not stay around a large number of flowing workpieces 10, The light passes through the protrusion 29e of the storage means 29 and is discharged from other parts.
And by continuing these, a coating component adheres uniformly to the surface of many to-be-processed objects 10, and it solidifies, Preferably it hardens | cures and a film is formed.

Thereafter, the object to be processed 10 is taken out from the tumbler coating apparatus 20, and the film is sufficiently cured by reheating the large number of objects 10 on which the film is formed on the surface by a heating apparatus capable of maintaining the predetermined temperature. Can be made.
Therefore, in such a reheating treatment, the coating component of the coating may be kept in an oven at a temperature at which it can be completely cured, for example, at a temperature of 200 ± 10 ° C. for about 90 to 160 minutes. A coated molded body can be obtained.
Even when such a reheating process is performed, the reheating process can be performed quickly and easily by moving the workpiece 10 to the oven while being accommodated in the accommodating means 29. Can do.

[Second Embodiment]
The second embodiment is a tumbler coating method for coating a coating component on the surface of a large number of objects to be processed using the tumbler coating apparatus of the first embodiment,
A tumbler coating method characterized by simultaneously spraying a coating treatment liquid from a spraying means and solidifying a coating component by heating of a heating means while flowing a large number of objects to be processed at the bottom of the containing means. .

That is, in the tumbler coating method using the predetermined tumbler coating apparatus 20 shown in FIG. 1, spraying the coating treatment liquid from the spraying means 31 while flowing a large number of objects to be processed 10 at the bottom 29 b of the storage means 29, Since the coating component can be solidified by heating the heating means at the same time, the coating treatment liquid is uniformly adhered to a large number of objects to be treated 10, and adhesion between the objects to be treated 10 is prevented and solidified uniformly. be able to. Therefore, it is possible to cover a large number of objects to be processed 10 with a coating component thinly and uniformly while preventing the objects to be processed 10 from being bonded to each other.
Hereinafter, embodiments relating to the tumbler coating method will be specifically described.

1. Pre-treatment step As a pre-treatment step, it is preferable to perform a sand blast treatment by spraying a blast medium such as alumina particles or zirconia particles on a large number of objects to be treated 10.
That is, the surface of a large number of objects to be processed 10 is made of metal, and by subjecting the objects to be processed 10 to sandblasting by spraying alumina particles or the like, oxide films or contaminants on the surface of the large number of objects to be processed 10. Can be efficiently removed.
Therefore, after that, by carrying out a predetermined tumbler coating method, it is possible to stably form a thinner and more uniform coating component film.

More specifically, in order to perform sandblasting on a large number of objects 10 to be processed, for example, alumina particles having an average particle diameter in the range of 80 to 200 μm are prepared and shown in FIG. Housed in a blast tank 55.
Next, a large number of objects to be processed 10 are flowed by using a sandblasting device 50 having a polygonal shape as shown in FIG. Let
That is, a large number of objects to be processed 10 are accommodated in the rotation accommodating portion 58 and rotated, for example, by rotating at a rotation speed of 1 to 30 rpm as indicated by an arrow in the drawing, a large number of inside the rotation accommodating portion 58. The workpiece 10 can be made to flow.
In addition, since the rotary accommodating portion 58 is surrounded by a metal or plastic protective member 59, the blast medium effectively prevents the blast medium from being scattered to the outside and prevents contamination from entering the inside. It can be effectively prevented.

Accordingly, in this state, the nozzle 51 including the operation control means 52, the injection direction control means 53, the compressed air control means 54, the blast tank 55, and the airflow generation device 56 is an example, but the blast Sandblasting is performed by spraying alumina particles as the medium 57 at a pressure of 0.1 to 0.5 MPa for 10 to 40 minutes.
That is, such a sandblasting process can sufficiently and efficiently remove oxide films and contaminants existing on the surface of a large number of objects 10 to be processed.
On the other hand, the used alumina particles 57 pass through the pores 58a of the rotation accommodating portion 58 and are collected by the collection weight 58b by their own weight or centrifugal force, and are used for the next sandblast treatment through the blast tank 55.
In addition, after performing a sandblasting process, since the alumina particle 57, contaminants, etc. may adhere to the to-be-processed object 10, the to-be-processed object 10 is wash | cleaned using a volatile organic solvent, and is dried. It is preferable.

2. Application Step (1) Accommodation Step The accommodation step is a step of accommodating a predetermined amount of the object to be processed in the accommodation space.
That is, after performing a sandblasting process etc., before implementing an application | coating process, it is a process of accommodating a predetermined amount of to-be-processed objects in accommodation space.

In that case, it is preferable to determine the amount of the object to be processed so that the volume of the object to be processed is 0.01 to 30% by volume of the volume of the storage space (100% by volume).
The reason for this is that the production efficiency of the object to be processed may be significantly reduced when the amount of the object to be processed is less than 0.01% by volume.
On the other hand, when the amount of the object to be processed exceeds 30% by volume, it may be difficult to stably form a uniform film.
Therefore, it is more preferable to set the storage amount of the object to be processed to a value in the range of 0.1 to 10% by volume of the volume of the storage space (100% by volume), and to a value in the range of 1 to 5% by volume. More preferably.

(2) Rotation process Moreover, a rotation process is a process of rotating many to-be-processed objects in accommodation space.
That is, a container means having a cylindrical part and a bottom part and formed of a net-like material, and by rotating at an angle together with the rotating means, a large number of objects to be processed are utilized in the vicinity of the bottom part. And containing means for fluidization.
And the protrusion part which protrudes upwards is provided in the bottom part of this accommodating means, and it is comprised so that many to-be-processed objects may flow stably between a protrusion part and a cylinder part. Therefore, a large number of objects to be fluidized can be stirred efficiently and gently.

(3) Heating process Moreover, a heating process is a process of heating many to-be-processed objects, rotating in a storage space.
That is, the heating means includes a heated gas jetting part that jets the heated gas, and the coating treatment liquid is configured to be sprayed on a large number of objects to be processed together with the heated gas. Solidification of the coating component of the coating treatment liquid adhering to the object to be treated can be promoted by the temperature of the heated gas and the airflow.

  Moreover, since the heating means includes a heater that can heat the inside of the accommodation space by heating the rotation means, the inside of the accommodation space can be easily maintained at a temperature at which the coating component of the coating treatment liquid can be solidified. Therefore, even if a large number of objects to be processed flow in the storage means, the temperature of the atmosphere in contact with the surface of each object to be processed tends to be stable, and the coating components of the coating processing liquid adhering to the objects to be processed are uniformly solidified. It becomes easy.

(4) Spraying process Moreover, a spraying process is a process of spraying a coating processing liquid, making many to-be-processed objects flow in a heating state in accommodation space.
That is, a small amount of coating treatment liquid is sprayed over a long period of time toward a large number of objects to be processed flowing inside the storage means by the spraying means, thereby thinly and uniformly covering the surface of the large number of objects to be processed. The treatment liquid is attached.
In addition, by heating a large number of objects to be processed flowing in the storage means by the heating means, it is easy to uniformly solidify the coating components attached to the surface, and the objects to be processed are bonded to each other via the coating components. It becomes easy to prevent.

In addition, it is preferable that a coating process liquid is a solution or dispersion liquid containing the coating component which consists of at least one of a polyimide resin precursor and a polyimide resin composition as partly mentioned above.
That is, since the heat treatment is performed to heat the processing object to a temperature at which the coating component can be cured by the heating means, it is easy to ensure the strength of the coating component while sequentially applying the coating processing liquid to a large number of the processing objects. For this reason, the coating film is hardly damaged during the coating treatment liquid spraying process, and it becomes easier to form a uniform film more reliably.

3. Post-treatment step (1) Reheating step In addition, although it is an optional step, the coating component in the obtained object to be treated is heated at a predetermined temperature in order to further completely cure or remove excess solvent. It is preferable to provide a reheating step.
For example, in the case of a coating treatment liquid containing a coating component comprising at least one of a polyimide resin precursor and a polyimide resin composition, reheating treatment can be performed in an oven at a temperature of 200 ± 10 ° C. for about 10 to 160 minutes. preferable.

(2) Cooling step Although it is an optional step, it is preferable that the obtained object to be processed is allowed to stand at room temperature for a predetermined time and naturally cooled to room temperature or near room temperature.
The reason for this is that by cooling in this manner, the internal strain in the coating can be reduced, and the adhesion and durability of the coating can be significantly improved.
In addition, as an example, it is preferable to naturally cool the obtained object to be processed at room temperature for about 10 to 60 minutes.

(3) Inspection process Similarly, although it is an optional process, the appearance of the obtained object to be processed, the thickness of the film, the electrical insulation of the film, the retention rate of the object to be processed, etc. are measured, and each is within a predetermined range. It is preferable to provide an inspection process for confirming that the value is.

[Example 1]
In Example 1, as shown below, a coated molded article was prepared using the accommodating means provided with the protrusions shown in Table 1, and the thickness of the polyimide layer was measured. The effect of height on the coating was confirmed.

1. Preparation of coated molded product (1) Preparation of workpiece First, the workpiece to be used was molded into a shape as shown in FIG. 4 from a soft magnetic material, and the total surface area per piece was 10 mm ^2. Was 40 A / m.
Note that the coercive force of the object to be processed easily decreases when the temperature is increased to about 500K.

(2) Sandblasting The sandblasting was performed using a sandblasting apparatus in which the rotation accommodating portion has an octagonal side wall as shown in FIG.
In this treatment, the rotation accommodating portion was rotated at 11 rpm, and alumina particles having an average particle diameter of 7 μm were sprayed at a pressure of 0.2 MPa for 60 minutes while the workpiece was flowing inside.

(3) Coating process The coating treatment liquid is composed of a thermosetting polyimide resin having a concentration of 10% by weight, tetrahydrofuran (THF) as a solvent, and N-methyl-2-pyrrolidone (NMP). : A liquid mixed so that NMP was 1: 2 by weight was prepared and used. The viscosity of the obtained coating treatment liquid was 14.9 ± 0.5 seconds (measurement temperature: 25 ° C.) with a special viscometer.
In addition, as shown in Table 1, the accommodating means has an inner diameter D1 of the cylindrical portion as shown in FIG. 3, an outer shape D2 of the connecting portion with the bottom of the protruding portion, a height H1 of the cylindrical portion, and a height H2 of the protruding portion. And made of a mesh material made of 60 mesh stainless steel.

  In addition, in the tumbler coating apparatus, as an example, the rotation angle of the rotation means L of the rotation means is 60 °, the rotation speed of the rotation means is 7 rpm, the heating temperature of the rotation means is 50 ° C., and the heating gas is ejected from the heated gas ejection section. The temperature of air was set to 250 ° C., and the pressure of the blowing gas of the blowing means was set to 0.2 MPa.

  In the coating process using the tumbler coating apparatus, 6000 objects to be processed by sandblasting are accommodated in the accommodating means, and the accommodating means is disposed in the accommodating space of the rotating means, and the tumbler coating apparatus is operated under the above-described conditions. Driven, for 150 minutes, 0.8 ml of the coating treatment liquid was sprayed from the spraying means at a constant supply amount, and solidified on the surface of the workpiece.

(4) Heat treatment The heat treatment of the object to be processed is to take out the storage means containing the object to be processed from the tumbler coating apparatus, and then store it in the heating space and hold it at 200 ° C. for 120 minutes. It went by.
In addition, after performing this heat processing, the to-be-processed object was taken out from the accommodating means, and naturally cooled on the conditions of room temperature and 60 minutes, and the to-be-processed object of Example 1 was obtained.

2. Evaluation of Coated Molded Product A coated film made of about 8 μm polyimide was formed on the coated molded body obtained as described above. Five samples were randomly sampled from the coated molded body, and the film thickness of the coating on the coated molded body was measured according to JIS 2001 using a surface roughness meter (Surfcoder 1700a, manufactured by Kosaka Laboratory). The average value was calculated. Furthermore, the standard deviation (σ) of the film thickness is calculated and is shown in Table 1 as the film thickness variation.

[Examples 2 to 5]
In Examples 2 to 5, as shown in Table 1, the entire surface of the object to be processed is a polyimide layer as in Example 1 except that each of the accommodating means having different protrusion heights (H1) is used. A coated molded article coated with was prepared and evaluated.

[Comparative Example 1]
In Comparative Example 1, as shown in Table 1, the entire surface of the object to be processed is polyimide as in Example 1 except that the height of the protrusions is zero, that is, the housing means without protrusions is used. Coated molded articles coated with layers were prepared and evaluated.

As is clear from Table 1, in Examples 1 to 5 using the housing means provided with the protrusions, as compared with the case where the housing means not provided with the protrusions is used as in Comparative Example 1, the film thickness varies. It was confirmed that it was possible to form a thin, uniform and uniform polyimide layer.
In particular, as in Examples 3 to 5, if the ratio (H1 / H2) of the height (H2) of the protrusion to the height (H1) of the housing means is in the range of 1.5 to 5, the example Compared to 1 (H1 / H2 = 1.2) and Example 2 (H1 / H2 = 7), it was confirmed that the variation in film thickness can be further reduced.
Furthermore, in Examples 1 to 5 and Comparative Example 1, it was confirmed that the retention strength before and after the coating of the object to be processed was in the range of 0.3 to 0.4 Oe, and there was no significant difference. .

According to the tumbler coating apparatus of the present invention and the tumbler coating method using such a coating apparatus, it is possible to effectively prevent the workpieces from adhering to each other and to coat a large number of small workpieces. As a result, even a thin film having a uniform thickness can be formed efficiently.
Therefore, the tumbler coating apparatus and the tumbler coating method of the present invention are used to produce an object to be processed having a predetermined film, from the viewpoint of electrical characteristics, mechanical characteristics, or environmental characteristics, and various ferrite molded products and various electrical products. Applications to parts, various automobile parts, various machine parts, etc. are expected.

10: workpiece, 11: corner, 20: tumbler coating device, 21: support, 23: rotation drive (motor), 25: accommodating space, 27: rotating means, 27a: rotating, 27b: bottom, 27c: tip portion, 27d: flange, 29: accommodating means, 29a: tube portion, 29b: bottom portion, 29c: flange, 29d: reinforcing portion, 29e: protrusion, 29f: connecting portion, 29g: substantially flat bottom portion, 31: Spraying means, 31a: Coating treatment liquid, 35: Heated gas ejection section, 48: Storage tank, 49: Supply source of compressed air, 50: Sand blast device, 51: Nozzle, 52: Operation control means, 53: Injection direction Control means, 54: Compressed air supply means, 55: Blast tank, 56: Airflow generator, 57: Blast material, 58: Rotation accommodating part, 58a: Fine hole, 58b: Recovery part, 59: Protection member

Claims (8)

A rotating means having a storage space and rotating around a rotation axis inclined at a predetermined angle with respect to the horizontal direction;
In a state of being formed of a net-like material, having a cylindrical portion and a bottom portion, mounted in the accommodation space such that the center portion of the bottom portion matches the rotation axis, and a large number of objects to be processed are accommodated therein. A receiving means that rotates together with the rotating means;
Spraying means for spraying the coating processing liquid toward a large number of objects to be processed flowing in the housing means;
Heating means for heating a large number of objects to be processed flowing in the accommodating means, and solidifying the coating components attached to the surfaces of the large number of objects to be processed;
A tumbler coating characterized in that a protrusion projecting upward of the rotating shaft is provided at the bottom of the accommodating means, and a large number of objects to be processed are allowed to flow between the protrusion and the cylindrical portion. apparatus. The said heating means is provided with the heated gas ejection part which ejects heated gas, and sprays the said coating process liquid with respect to said many to-be-processed objects with the said heated gas. Tumbler coating equipment. The tumbler coating apparatus according to claim 1, wherein the heating unit further includes a heater capable of heating the inside of the accommodation space by heating the rotating unit. The said rotation means has the side surrounding wall and bottom wall which surround the said accommodation space, and the said bottom wall and the said protrusion part are spaced apart so that ventilation | gas_flowing is possible. The tumbler coating apparatus as described in any one of Claims. The tumbler coating apparatus according to any one of claims 1 to 4, wherein the coating treatment liquid is a solution containing a polyimide resin precursor or a polyimide resin composition as a coating component. A tumbler coating method in which a coating component is coated on the surface of a large number of workpieces using a tumbler coating apparatus,
The tumbler coating device is:
A rotating means having a storage space and rotating around a rotation axis inclined at a predetermined angle with respect to the horizontal direction;
In a state where the storage space is mounted, formed of a mesh-like material, has a cylindrical portion and a bottom portion, the bottom portion is arranged in a direction intersecting the rotation axis, and a large number of objects to be processed are accommodated therein. A receiving means that rotates together with the rotating means;
Spraying means for spraying a coating treatment liquid containing a coating component for coating the surface of a large number of objects to be processed toward a large number of objects to be processed flowing in the storage means;
Heating means for heating a large number of objects to be processed flowing in the accommodating means, and solidifying the coating components attached to the surfaces of the large number of objects to be processed;
While providing a protrusion projecting upward of the rotating shaft at the bottom of the housing means, while flowing the large number of objects to be processed between the protrusion and the cylindrical portion,
A tumbler coating method comprising simultaneously spraying the coating treatment liquid from the spraying means and solidifying the coating component by heating of the heating means. The tumbler coating method according to claim 6, wherein the thickness of the coating on the surface of the object to be processed is set to a value in the range of 0.1 to 10 μm. 8. The tumbler coating method according to claim 6, wherein the coating treatment liquid is sprayed by using the tumbler coating apparatus after the alumina particles are sprayed on the multiple objects to be processed and sandblasted. 9.

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