JP3474472B2 - Seamless tubular film molding equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improved molding apparatus for molding seamless tubular films.

[0002]

2. Description of the Related Art Generally, a seamless tubular film, that is, a seamless tubular film, is formed by coating a raw material liquid on the entire surface of an inner surface or outer surface of a metal drum and heating and drying. Each method has advantages and disadvantages, but as a method that can be reliably molded with high accuracy, molding using the inner surface, that is, injecting the raw material liquid into the inner surface of the cylindrical body, uniformly casting while rotating at high speed, heating This is a method of drying, which is generally called a centrifugal casting method.

[0003]

A problem particularly in forming a seamless tubular film by a centrifugal casting device is that a highly accurate film having substantially no thickness unevenness can be formed more quickly (1). It is not possible to mold for a long time per batch). Here, the thickness unevenness is a phenomenon that it is thick especially in both peripheral portions and thin in the central portion, and the phenomenon becomes larger as the lateral width becomes larger. The reason for the thickness accuracy and the molding time is also due to the heating means, but it is also considered that it is largely due to the variation in the concentration of evaporants such as organic solvents generated in the metal drum in the drum. To be

Therefore, the inventors of the present invention have diligently studied to solve the above-mentioned problems, mainly by improving the means for discharging the evaporated material. As a result, they finally found a solution and arrived at the present invention.

[0005]

Means for Solving the Problems That is, the present invention is achieved by first providing a seamless tubular film forming apparatus as set forth in claim 1. That is, it comprises a rotating means (4) for rotating the molding hollow cylindrical body (1) and a heating means (2) for heating from the outside, and a seamless process for supplying and molding a liquid resin into the hollow cylindrical body. In a tubular film forming apparatus, the same as the inert gas supply means (F) having a mesh-shaped fine perforated wire mesh at the ejection port in order to actively ventilate the vaporized substances generated by the molding inside the hollow cylindrical body. A discharge means (S) for discharging the evaporate together with the inert gas to the outside of the system is provided. By this means, the film can be molded with higher thickness accuracy and faster molding.

On the other hand, in a second aspect of the present invention, in the seamless tubular film forming apparatus, which is the premise of the first aspect, the hollow cylindrical body (1) for forming has a predetermined gap between the end faces of the hollow body and the cylindrical body. Double lid (5) placed with
And the double lid comprises an inner lid and an outer lid.
The inner lid and the outer lid are opposed to each other with a gap in the entire circumferential direction, and a supply nozzle (5c) for supplying an inert gas into the gap.
There is provided a tubular film forming apparatus characterized by being provided with. By adopting this measure, it is possible to prevent dust and the like from entering the hollow cylindrical body from the outside, so that the flawless film can be obtained.

The inventions of the respective claims described in claims 3 to 6 are provided as one invention in a preferable form depending on claim 1. Hereinafter, the present invention will be described in more detail with reference to the drawings.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION First, a seamless tubular film (hereinafter referred to as SL film) molded by a molding apparatus in the present invention is a film made of generally known thermoplastic or thermosetting resins. The raw material for molding is generally a resin solution prepared by dissolving each resin in an organic solvent at a predetermined concentration. However, in the case of a precursor before reaching the resin or a two-dimensional (straight-chain) polymer, there are some that are themselves liquid at room temperature or slightly heated. In such a case, it is not always necessary to use an organic solvent, and molding with a solvent-free bulk is also possible. Therefore, in the present invention, although effective for a resin solution dissolved in an organic solvent,
It is not necessary to use such a solution, and any solution can be applied as long as it is in a liquid state and a desired synthetic resin film can be molded by centrifugal casting. In the case of the thermosetting resin,
Since it is insoluble in any organic solvent by itself, the stage of the precursor, which is itself in a liquid or solid state, is used as the forming raw material. If this stage is liquid, no organic solvent is required, but if it is solid, it is necessary to use a material dissolved in the solvent as a raw material.

If necessary, various additives may be mixed with the molding raw material. When molding a molding raw material with this additive, the additive is more uniformly dispersed in the molding apparatus according to the present invention. This is also one of the features, considering that it is generally difficult to uniformly disperse a molding raw material with additives by centrifugal casting.

Further, the inert gas to be supplied does not react with the above-mentioned respective resins used for molding or the organic solvent contained in the resin during the heat molding, and evaporates the evaporate smoothly and efficiently. There is no particular limitation as long as it is a gas discharged to the outside. Generally, air at room temperature, nitrogen gas, etc. can be exemplified. Of course, it may be a heated inert gas heated to a predetermined temperature.

Further, adjusting the amount of the inert gas supplied and the amount of the same gas discharged so as to maintain the gas concentration in the molding hollow cylindrical body (1) at a certain value evenly means that the amount of evaporate from the molding is Since the thickness can be positively adjusted, unevenness in the thickness of the film can be reduced and the accuracy can be further improved, which is preferable.

[0012]

(Embodiment 1) FIG. 1 is a side view of a main part of the present apparatus, and FIG. 2 is a sectional view taken along line AA. Here, 1 is a metal drum made of iron or stainless steel whose inner surface is mirror-finished as an example of the hollow cylindrical body (1) for molding. Barriers 1a are provided around both ends of the metal drum 1 to prevent the casting raw material from flowing out of the system. The metal drum 1 has a pair of rotating rollers 4 around which heat-resistant rubber is provided, and two pairs of the rotating rollers 4 are placed and supported on the rotating rollers 4. Therefore, the metal drum is freely rotated by the rotation of the roller 4. Reference numeral 4a is a rotary gear that works in conjunction with a rotary motor (not shown).

As the rotating roller 4, four short rolls of the same size are used, which keeps the horizontal accuracy in rotating the metal drum 1 with higher accuracy and at the same time. This is because it is effective to prevent the heat given to the heat from escaping to the outside of the system by heat conduction and to smoothly rotate. This effect becomes greater as the width of the drum 1 becomes longer. Of course, it is possible to use two long rolls instead of this short roll. Also, the roller 4
May be used in a state in which one or more pairs are further added and the drum 1 is placed on it, or may be used to prevent blurring.

The entire outer surface of the metal drum 1 is plated with black chrome to form a black layer. The blackening means is not limited to the plating and may be, for example, coating with a black heat-resistant paint, and is not specified. By having this black layer, the metal drum 1 by means of external heating
The temperature control inside the drum can be performed with higher accuracy by improving the heat transfer to the drum and combining the radiation temperature sensor 3.

The radiation temperature sensor 3 is capable of faithfully catching infrared energy emitted from the black surface corresponding to the amount of heat given to the metal drum 1. It is possible to control the temperature with high accuracy. The radiation temperature sensor 3 is arranged at a proper position around the surface of the metal drum 1 at a fixed position. The distance here is within the measurement field of view,
Specifically, the distance from the measurement point at the temperature sensor is 5
It is better to keep it within 00 mm. This is because the temperature can be controlled more accurately.
This is illustrated by being separated by m and is connected to an amplifier (not shown).

It is also possible to use another temperature sensor, for example, a non-contact type surface temperature measuring thermocouple, in place of the radiation temperature sensor 3 to measure with a minute gap of 1 to 2 mm. However, if an air flow or the like is generated in the gap, it becomes difficult to measure the accurate temperature, so it is necessary to take measures to prevent this.

On the other hand, the far infrared heater 2 is shown here as the heating means. As is clear from the cross-sectional view taken along the line AA of FIG. 2, this arrangement position is located near the metal drum 1 and substantially in the middle of the two pairs of short rollers 4, and is approximately 180 degrees with respect to the radiation temperature sensor 3. It is in degrees. The length of the far infrared heater 2 is almost the same as the width of the metal drum 1. Of course, the type of heat source, the number of arrangements, the arrangement position, etc. do not limit the present invention, but among them, the arrangement position is set at a certain distance so that infrared rays emitted from the heat source are not directly sensed by the temperature sensor. It is better to place them separately.

Next, the inert gas supply means (F) and the discharge means (S) provided inside the metal drum 1 of the above apparatus will be described.

First, since both of the above-mentioned means are internally provided, the evaporation of the evaporative substance generated by molding is further promoted, and the evaporative substance can be recovered without leaking out of the system. However, the thickness accuracy of the SL film to be obtained is not sufficiently satisfied by simply providing both of them, and in particular, both end portions tend to be thicker than the central portion. Therefore, in order to solve this point all at once, a nozzle having a mesh-shaped fine-mesh wire net (hereinafter simply referred to as a mesh-shaped wire net) is used especially at the jet port of the inert gas supply means.

Therefore, the inert gas supply means (F) having a mesh wire mesh at the jet outlet will be described in detail. This means corresponds to F in FIG. The F is arranged so as to be located in the center of the metal drum 1, but it also supports its right end with 8a, and the air cylinder 8 on the linear slider 8b.
I also try to move left and right by. This is because after the molding is completed, the metal drum is pulled out from the metal drum to facilitate the subsequent work.

The specific structure of the means F itself is shown in the sectional view taken along the line AA of FIG. 2 and the perspective view of FIG. The gas supply means F is provided with a secondary ejection port 6a made of a mesh wire mesh at an opening on one side in the longitudinal direction of a long rectangular pipe 6 having substantially the same length as the metal drum 1. Two long rectangular pipes having the same length are arranged to form a long double pipe. One of the two long rectangular pipes is a long rectangular pipe 10 in which a plurality of short nozzles having a mesh wire mesh as the primary ejection ports 10a are laterally installed at a constant pitch on the side surface thereof. It is another long rectangular pipe 11 connected through a pipe 11a. Since the long rectangular pipe 11 is additionally provided here, the gas sent from the gas supply source F is temporarily buffered here and sent from the guide pipe 11a connected at the center, This is because it is sent as dispersed air to the short nozzles of the primary ejection port 10a. However, the long rectangular pipe 11 may be omitted, or another member having a function of buffering the supply gas flow may be additionally provided instead of the long rectangular pipe 11. Here, the terms "primary" and "secondary" mean that the ejected gas is indirect or direct with respect to the molding resin, as can be seen from the above. Further, each square pipe may be a circular pipe.

The direction of the primary ejection port 10a and the direction of the secondary ejection port 6a are oriented with a difference of 90 degrees. This is because the inert gas from the primary ejection port is once applied to the inner wall surface of the long rectangular pipe 6 on the outer side to be further buffered, dispersed and supplied to the secondary ejection port 6a. This is because in the process from the supply of the inert gas to the ejection into the metal drum 1, it is possible to eliminate the pressure unevenness of the gas and to eject in the state of a uniform dispersed flow without wind ripples as much as possible by the centrifugal casting method. This is based on the knowledge that the evaporation of the evaporated material is further promoted and that the SL film with higher thickness accuracy can be obtained. Therefore, in the case of using this double tube, it is desirable to set the nozzle angles of both nozzles within a range of about 180 to 60 degrees and separate them.

Next, a detailed description will be given of the mesh-shaped wire net included in the jet port. The effect of this mesh-like wire mesh is that the inert gas is ejected through this (compared to the case where it is not present), resulting in a completely homogenized jet gas having no wind ripple. As a result, it is possible to obtain almost complete promotion of evaporation of the above-mentioned evaporant and high accuracy of SL film thickness.

Here, the mesh-like wire mesh is a metal mesh material having innumerable fine holes, and the size of the fine holes is generally about 5 to 100 μm, preferably 10 to 80.
μm, and more preferably 15 to 60 μm. Therefore, there is no limitation on its shape or method of making. For example, stainless steel,
Starting from fine perforated wire mesh obtained by weaving this with a fine metal wire made of copper, brass, etc. as a raw thread with a predetermined woven structure, sintered wire mesh obtained by sintering it, and sintering between contact points of fine spheres Examples thereof include a fine-hole sintered spherical wire mesh obtained by connection, a porous body provided with innumerable fine holes, and a metal plate such as foam.
The predetermined weaving structure is generally the same as that of the fiber woven fabric, but considering the above-mentioned effects and ease of weaving, the flat 12, twill 13, satin 14, weft 15, half-latitude 16, flat tatami mat shown in FIG. 1
7, and each structure of Tatami 18 can be preferably exemplified. Reference numeral 19 in FIG. 4 is an example of a sintered spherical wire net made by sintering brass microspheres 19b, and the micropores formed are substantially triangular as shown by 19a. The meaning of the numerical value of the size of the fine pores means the length of one side of the pores converted into a square shape.

The mesh-like wire net is attached to the outlet of the nozzle on the side where at least the inert gas is directly jetted into the metal drum 1. In FIG. 1, one side opening of the long rectangular pipe 6 of the secondary ejection port 6a (metal drum 1
(Direct injection into the interior) and a short nozzle of the primary ejection port 10a. Providing the primary ejection port also improves the uniform dispersion of the gas, but is not essential.

The mesh wire net may be of one kind, but it is desirable to attach it in a laminated body of 2 kinds or more and 5 kinds or less,
And, at least two kinds of laminates made of the wire mesh of different kinds are preferable. This is also because the inert gas undergoes further buffering and dispersion (without wind ripples) while passing through the laminate. Here, the laminating means includes, for example, simply stacking, further pressing, sintering, and fusion between the intertwined yarns. The long rectangular pipe 6 of the secondary ejection port 6a in FIG. 1 is sintered by using three types of texture meshes of flat 12, half-latitude 16 and flat tatami 17 among the 7 types shown in FIG. This is an example of using a laminated mesh as a layered body, and the short nozzle of the primary ejection port 10a is formed into a columnar shape (sintered body) by 19 sintered spherical wire mesh and is screwed. In addition, the number of short nozzles having the primary ejection ports 10a may be set laterally so that the ejected gases do not interfere with each other so much.

The long rectangular pipe 6 on the secondary side may be replaced with a short nozzle as on the primary side, but from the viewpoint of the above-mentioned effect, it is preferable to use a single long nozzle type.

On the other hand, when the inert gas ejected into the metal nozzle 1 is viewed from the viewpoint of wind speed, it is about 0, 01 to 0, 1 m / sec.
It may be set to preferably 0,03 to 0,7 m / sec. The supply at such a wind speed is because the buffering and dispersing action on the way becomes more effective.

Next, the outside discharge means (S) will be described. This means is for positively discharging all the gaseous substances in the molding hollow cylindrical body (1) provided by the inert gas supply means (F), that is, for rapidly discharging them out of the system. , F in FIGS. 1 and 2. Specifically, it is shown by a square pipe 7 made of stainless steel, and suction holes 7a are formed at a constant pitch in this pipe so that the suction pump S1 sucks and discharges it from one end. Alternatively, the suction hole 7a may be a slit-shaped long hole,
Further, a suction hole in which the mesh wire mesh is attached to the elongated hole may be used. . Of course, there are no restrictions on the shape, size, number, etc. of these holes for discharge.

Further, the positional relationship between the suction hole 7a of the outside discharge means S in the metal drum 1 and the long square pipe 6 having the mesh-shaped wire net 6a (long nozzle) used for the inert gas supply means F is provided. Are preferably as far apart as possible in the direction of rotation of the drum. This is to prevent the gas ejected from the long nozzle of the long rectangular pipe toward the drum surface from being sucked from the suction hole as it is without vaporizing the vaporized material. . Here, the rotation direction of the drum means that most of the gas ejected from the long nozzle 6a as shown by an arrow (→) in the AA sectional view of FIG. Taken away in the direction of rotation. Therefore, it is better to suck at the end position where it can be taken away as much as possible. FIG. 1 shows an example in which both nozzles are separated by 270 degrees in the rotation direction, but it is preferable to set the optimum condition within the range of 90 to 360 degrees. Preferably 1
If it is 80 to 270 degrees, the supply amount and the discharge amount are easily balanced and stabilized. The amount of the inert gas ejected into the metal drum 1 is in the range of about 5 to 100 L / min (changed depending on the cylinder size), but the suction is performed in the same amount or less and half or more, It is desirable not to increase.

Next, the second aspect will be exemplified. This is Figure 1
5 is a double lid attached to both side surfaces of the metal drum 1 with a slight clearance, and at least one of them is attached so as to move left and right to open and close the side surface of the drum. In this figure, both lids are provided with a lateral movement mechanism. That is, the support rod 9a of the left lid is slid on the linear slider 9b by the air cylinder 9. On the other hand, the lid on the right side is a long rectangular pipe 6 provided integrally.
It is fixed to the right ends of the (inert gas supply side) and the long rectangular pipe 7 (suction side), and is opened / closed by lateral movement of the pipe. Further, the lid 5 is not a simple lid, but an inner lid 5b which is opposed to the lid 5 with a constant gap (about 0.1 mm to 1 mm).
And an outer lid 5a, and the outer lid is provided with an introduction hole 5c for supplying an inert gas and discharging it from the gap to the entire periphery. Incidentally, the outer lid 5a has a concave shape in its central portion. This is because the introduced gas is once stagnant and is discharged from the entire circumference in a uniform flow, but this can also be done by changing the installation content (number, shape, position) of the inlet 5c. As such, it is not specific to this.

Since the double lid is provided, it is possible to prevent dust and the like from entering through the gap between the metal drum 1 and the inner lid 5b by the gas curtain. Here, it is considered that the dust or the like from the outside is caused by the gas flow inside which is formed by the rotation of the drum 1.

The molding apparatus shown in FIG. 1 may be used by enclosing the main body portion (metal drum) or the whole with a casing and storing it in one molding chamber.

(Example 2) (Example of molding SL film) Using the apparatus illustrated in Example 1, an SL film was molded under the following conditions and the quality was confirmed. Molding raw material: Polyamic acid, which is a precursor of thermosetting polyimide, is dissolved (15% by weight) in a mixed solvent of N-methylpyrrolidone and dimethylformamide, and carbon black (additive: 9% by weight) is added thereto. Mixed and dispersed polyamic acid solution.・ Size of the metal drum 1: inner diameter 180 mm, length 600
mm ・ Temperature (surface of the drum 1): 110 ± 1 ° C. ・ Air (normal temperature) (inert gas) supply rate: 60 L / min ・ Primary ejection port: Diameter 8 mm made of sintered spherical wire mesh with fine pores of 50 μm, A cylindrical short nozzle with a screw height of 10 mm. -Secondary ejection port: A long sintered wire net in which a plain woven mesh having fine pores of 15 µm is used as a basic layer, and a half-weft mesh and a flat tatami mesh are combined and laminated in five layers. -Rotation speed of the drum 1: 150 (rpm) -Suction amount: 30 L / min-Molding time: 2, 5 hours-Amount of air released from the double lid 5: 15 L / min The molding raw material is finally obtained The polyimide SL film was weighed so as to have a thickness of 100 μm, and was poured while the metal drum 1 was slowly rotated.

Under the above-mentioned molding conditions, rotation is continued for 2 to 5 hours, stopped, cooled to room temperature, and supplied to a long rectangular pipe (6) for supply and discharge.
-7) was moved to the right from the metal drum 1 and pulled out together with the double lid 5, and the molded body was taken out. The obtained molded body was an SL film of carbon black-containing polyamic acid that was substantially unclosed (not imidized). And the S
The thickness of the L film was 200 ± 2, 7 μm, and there was no difference between the central portion and both side portions, and it was uniform. With respect to the final setting of the polyimide SL film having a thickness of 100 μm, the thickness of the polyamic acid SL film is 20.
0 ± 2,7 μm means that the solvent is completely evaporated and is not discharged, and imidization is not performed, but that the thickness is 200 ± 2,7 μm is uniform. The solvent remained evenly throughout, indicating that there was no unevenness.

Further, the obtained polyamic acid SL film was fixed on a cylindrical mold and put into a hot air dryer at 200 to 450 ° C. to completely remove the residual solvent and imidize it. A target polyimide SL film was obtained.
The thickness of the film was 103 μm ± 0.8 μm, which was constant, and even when the volume electric resistance was measured, there was no difference between the central portion and both side portions and it was constant. Even if this is taken, it can be seen that there was no variation in thickness and the carbon black was completely dispersed. In addition, dust was carefully checked with a magnifying microscope, but none was observed.

[0037]

Since the present invention is configured as described above, it has the following effects.

First, the SL film molded by the molding apparatus of the present invention is of high precision, which eliminates the high thickness at the both end portions than the central portion found in the prior art. This means that the film having a (horizontal) width can be obtained uniformly and uniformly.

Furthermore, the vaporized material produced by molding is
Since it is discharged evenly and completely out of the system without any unevenness, and therefore there is no organic solvent in the resin, the problem of quality performance is eliminated.

Since there is no quality problem due to dust or the like, it becomes easier to manage the whole production, and it becomes possible to produce more efficiently.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a molding device according to a first embodiment.

FIG. 2 is a cross-sectional view of a main part in the first embodiment.

FIG. 3 is an integrated perspective view of an inert gas supply means F and an outside-system discharge means S.

FIG. 4 is a plan view or perspective view showing each woven structure.

[Explanation of symbols]

1 metal drum 2 Far infrared heater 3 Radiation temperature sensor 4 Short roll Long pipe for air supply 5 double lid 6a 5-layer laminated wire mesh (secondary jet-long nozzle) 7a Suction port 10a Sintered spherical wire mesh (primary jet-short nozzle) 12-18 weave 19 Sintered ball mesh

Claims (6)

(57) [Claims] 1. A rotating means (4) for rotating the molding hollow cylindrical body (1) and a heating means (2) for heating from the outside.
In a molding device of a seamless tubular film for supplying and molding a liquid resin into the hollow cylindrical body, the vent is provided at the jet port in order to actively ventilate the evaporation generated by the molding inside the hollow cylindrical body. Molding of a seamless tubular film comprising an inert gas supply means (F) having a mesh-like fine perforated wire mesh and a discharge means (S) for discharging the vaporized material together with the inert gas to the outside of the system. apparatus. 2. A molding of a seamless tubular film, which comprises a rotating means for rotating a molding hollow cylindrical body (1) and a heating means for heating from the outside, and supplies a liquid resin into the hollow cylindrical body for molding. In the apparatus, the hollow molding cylinder is arranged at both ends thereof with a predetermined gap from the end surface of the cylinder.
Equipped with a double lid (5), which is an inner lid and an outer lid.
A lid, and the inner lid and the outer lid have a gap in the entire circumferential direction.
And a supply nozzle (5c) for supplying an inert gas in the gap between the two. 3. The inert gas supply means comprises a long double pipe having a primary ejection port (10a) and a secondary ejection port (6a), and the same primary ejection port is a plurality of short nozzles,
The seamless tubular film molding apparatus according to claim 1, wherein the secondary ejection port is a single long nozzle. 4. The mesh-shaped fine perforated wire net at the secondary ejection port is a laminate of at least two kinds of mesh wire nets having different woven structures, a sintered wire net obtained by sintering the same, or a sintering obtained by sintering fine particles. The apparatus for molding a seamless tubular film according to claim 1, which comprises a body. 5. A mesh wire net woven by a weave structure selected from the group consisting of flat, twill, flat tatami, twill tatami, satin, weft and half-weft weaves. 4. The seamless tubular film molding apparatus according to item 4. 6. The seamless tubular film molding apparatus according to claim 1, wherein the mesh-shaped fine perforated wire mesh has a pore diameter of 5 to 100 μm.