Continuous vacuum vapor deposition apparatus

Abstract: Continuous vacuum vapor deposition apparatus (7) in which a travelling substrate (1) is continuously fed into a vacuum chamber (2) from the atmosphere, subjected to vacuum vapor deposition in the vacuum chamber (2) and then conveyed out to the atmosphere caracterized in that a plurality of pressure chambers (16a, 16b, 16c) are demarcated from the atmosphere to said vacuum chamber (2) by means of seal devices, each said seal device includes one set of three pinch rolls (15a, 15b, 15c) arrayed in parallel on one plane and a pair of seal bars positioned on said one plane on the respective diodes of the pinch roll set. A temperature-adjustable wall (17) is disposed between the cooling roll (4) and the vapor deposition material container (9).

Description: BACKGROUND OF THE INVENTION: Field of the Invention: The present invention relates to a vacuum vapor deposition apparatus for vapor-depositing metal such as aluminium or the like or non-metal such as ceramics or the like onto a plastic film such as, for example, a film of polyester or the like or onto a paper sheet, and a vacuum vapor deposition apparatus for vapor-depositing metallic material or non-metallic material onto a substrate of various non-metallic materials other than plastics or various metallic materials. Description of the Prior Art: Heretofore, vacuum vapor deposition onto a plastic film, a paper sheet and the like has been carried out according to a batch system, but a continuous vacuum vapor deposition apparatus in which a base plate is continuously carried into a vacuum vapor deposition device has not been put to practical use. For reference, a continuous vacuum vapor deposition apparatus for dealing with a steel sheet in the prior art is illustrated in Fig. 6 and will be described in the following. In Fig. 6, reference numeral 001 designates a base plate, numerals 002a, 002b, 002c, ..... designate inlet side seal rolls, numerals 003a, 003b, 003c, ..... designate outlet side seal rolls, numerals 004a, 004b, 004c, ..... designate vacuum pumps, numeral 005 designates a vapor deposition device, numerals 006a, 006b, 006c, ..... designate pressure chambers, numeral 007 designates a vapor deposition chamber, numeral 008 designates deflector rolls, and numeral 009 designates a wrapping roll. The base plate passes through the pressure chambers 006a, 006b, 006c, ..... partitioned by seal rolls 002a, 002b, 002c, ..... each consisting of a pair of pinch rolls, then reaches the vapor deposition chamber 007 held at a predetermined degree of vacuum, and after it has been plated by vapor deposition by means of the vapor deposition device 005 within the vapor deposition chamber 007, it passes through the outlet side seal rolls 003a, 003b, 003c, ..... and is delivered into the atmosphere. The details of each seal roll are illustrated in Figs. 7 and 8, Fig. 8 being a cross-section view taken along line XI-XI in Fig. 7 as viewed in the direction of arrows. In Figs. 7 and 8, reference numerals 1011 and 1012 designate a pair of pinch rolls, numeral 1014 designates seal bars, numeral 1016 designates a casing, numeral 1017 designates an upstream side pressure chamber, numeral 1018 designates a downstream side pressure chamber, numerals 1019a, 1019b and 1019c designate leak gap clearances, more particularly reference numeral 1019a designates a gap clearance between the pinch roll 1011 and the seal bar 1014, numeral 1019b designates a gap clearance between the axial end of the pinch roll 1011 and the casing 1016, and numeral 1019c designates a gap clearance at the portion where the base plate 001 is not present between the pinch rolls 1011 and 1012. The upstream side pressure chamber 1017 and the downstream side pressure chamber 1018 are partitioned by the pinch rolls 1011 and 1012 and the seal bar 1014, and gas flows from the upstream side to the downstream side through the above-described small leak gap clearances 1019a, 1019b and 1019c. In addition, a process of forming a thin film by vacuum vapor deposition according to the above-mentioned batch system that is available for vapor-depositing metal or non-metal onto a base plate such as a paper sheet, a plastic film, etc. in the prior art, is such process that a preliminarily coiled base plate is charged within a vacuum envelope, and after the vacuum envelope has been sufficiently evacuated, vapor deposition is effected onto the base plate while it is running. One example of such batch systems in the prior art is illustrated in Fig. 9. In Fig. 9, a coiled base plate 201 is charged within a vapor deposition chamber 202 as connected to a take-up reel 205 via a deflector roll 203 and a cooling roll 204. After the space within the vapor deposition chamber 202 has reached a predetermined degree of vacuum as evacuated by a vacuum pump unit 2012, the base plate 201 is made to run as pulled by the take-up reel 205, and while it is cooled on the cooling roll 204 so as to suppress temperature rise caused by heating upon vapor deposition, the base plate 201 is vapor-deposited by a vapor deposition device 207. The vapor deposition devices 207 are disposed in multiple at a predetermined interval in the widthwise direction of a vapor deposition material 208 and the base plate 201, each vapor deposition device 207 is constructed of a container 209 for accommodating a vapor deposition material and a heating device 210 for heating the container 209, and it evaporates the vapor deposition material 208 towards the running base plate 201. Since the vapor deposition material 208 evaporated at this time would sputter not only to the just above but also in the oblique directions as spreading, edge masks 2011 are disposed at the positions overlapping the respective edge portions of the base plate 201 as spaced therefrom so that the sputtered material may not deposit onto the portion of the cooling roll 204 itself exceeding the width of the base plate 201. As described above, the vapor deposition work is a batch type of work, in which the number of the vapor deposition material containers 209 and the positions of the edge masks 2011 are preliminarily set by hands in accordance with the width of the base plate for each coil, and then evacuation, heating, running, vapor deposition and exposure to the atmosphere are effected repeatedly. In the vacuum vapor deposition apparatus in the prior art as illustrated in Fig. 6, it is necessary for suppressing the capacities of the vacuum pumps 004a, 004b, 004c, ..... to a small capacity that the area of the leak gap clearances 1019a - 1019c is reduced and thereby the flow rate of the gas flowing from the upstream side to the downstream side is made small. However, the gap clearance between the rotating pinch roll 1011 or 1012 and the stationary seal bar 1014 or the stationary casing 1016 cannot be made small exceeding a certain value in order to prevent contact therebetween, and so reduction of the leak gap clearance was limited. In addition, when gas flows through the leak gap clearance, fluttering of the base plate 001 would occur, and there was a large fear of resulting in generation of creases in the base plate 001 or cutting off of the base plate 001. In addition, as essential causes for the fact that vapor deposition onto the base plate 201 was effected according to the batch system and continuous vapor deposition has not been practiced as is the case with the vapor deposition apparatus shown in Fig. 9, the following problems are enumerated. Firstly, the cause exists in the point that an evacuation rate for generating a pressure gradient from the atmosphere side to the high vacuum side is enormous, and so, an evacuation pump system becomes very large. Therefore, as described above, the apparatus in which a running base plate was pinched by seal rolls and thereby a leak path cross-section area between the adjacent pressure chambers was reduced, was employed. However, in the case of a thin base plate such as a paper sheet or a plastic film, scratches would be generated on the base plate by pinching, and as this becomes a fatal defect in view of quality of products, such system was difficult to be put to practical use. Secondly, when the running base plate passes through the pressure chamber, the base plate would be fluttered by an airflow which flows in through the gap clearance between the pressure chambers, and this becomes a cause of scratches and breaking. A third problem resides in that since the vapor deposition material evaporates from the vapor deposition material container and sputters broadly, not only it deposits onto the base plate, but also it is trapped on the mask. In the case of the batch system, a period of one batch is short, hence the accumulated amount of the sputtered material is little, and a work of removing the accumulated material could be carried out for every batch. But in the case of the continuous system, the vapor deposition material trapped by the mask, the cooling roll and the like would successively increase the accumulated thickness, so that the gap clearance between the cooling roll and the mask would be blocked, and this becomes a cause for damaging the base plate passing through the gap clearance. Furthermore, in the case of the continuous system, it is necessary to be adapted for change of width of the running base plate, hence if the vapor deposition material is trapped on the cooling roll, depending upon the width the base plate would pass over the trapped vapor deposition material, and so, vapor deposition would become difficult. This problem can be said to be a very serious problem in practical use, in view of the fact that according to the batch system in the prior art the yield of the vapor deposition material is 50% or less. A fourth problem in the prior art resides in that since vapor deposition material is evaporated from a plurality of vapor deposition material containers, vapor spreading upwards from one container would form a vapor deposition film as overlapped with vapor evaporated from the adjacent containers, and so, in order to attain a uniform film thickness distribution in the widthwise direction, a skilled technique for controlling the temperature of the respective vapor deposition materials is required. In other words, in order to achieve continuous vapor deposition it is necessary to be continuously adapted for different base plate widths, and monitoring of the temperature of the individual vapor deposition materials and increase or decrease of the number of heated containers have a large time constant and are very disadvantageous in practical use. Besides the above-described principal problems, in order to realize continuous operations, it is necessary to achieve continuous feeding of a vapor deposition material from the atmosphere into the vacuum envelope as well as continuous feeding and winding of the running base plate, but in practice, any practical proposal for resolving the above-mentioned problems has not been made, and so, the continuous system has not been realized. Moreover, the vacuum vapor deposition apparatus of the one-batch one-coil type in the prior art as illustrated in Fig. 9 is inefficient and poor in productivity. Furthermore, it becomes necessary to expose the vacuum chamber to the atmosphere, upon every batch in the case of the batch system shown in Fig. 12, and when the running base plate has been cut. Then, each time a crucible is exposed to the atmosphere at a high-temperature state of 700 to 800°C, and sometimes at 1400°C, and therefore, the life of the crucible is shortened due to thermal damage. In addition, in order to prevent damage of the crucible, a work of ladling out a vapor deposition material such as aluminium or the like within the crucible and a work of taking care of the crucible are necessary. SUMMARY OF THE INVENTION: It is therefore one object of the present invention to provide a continuous vacuum vapor deposition apparatus comprising seal means which reduces a gap clearance cross-section area to minimum to suppress flowing of gas through the gap clearance as much as possible, and thereby the above-described fluttering of a running base plate is not generated. Another object of the present invention is to provide a continuous vacuum vapor deposition apparatus, in which an enormous evacuation rate is not required for the associated vacuum pump, fluttering of a running base plate in a vacuum vapor deposition apparatus is suppressed to minimum, the vapor deposition process can be readily adapted to any base plate having a different width without trapping a vapor deposition material on an exposed surface within a vapor deposition chamber, and feeding of a vacuum vapor deposition device from the atmosphere into a vapor deposition material container within a vapor deposition chamber can be achieved continuously. These objects are solved by a continuous vacuum vapor deposition apparatus as claimed in claims 1, 3 and 4. Preferred embodiments of the invention are defined in subclaims 2 and 5. The continuous vacuum vapor deposition apparatus according to the present invention as featured above can provide the following effects: 1) According to one aspect of the present invention featured above, owing to the facts that a seal device is formed of one set of three pinch rolls arrayed in parallel on one plane, among the pinch roll gap clearances at two locations in the set of three pinch rolls, an inlet side base plate running from the atmosphere towards the vacuum chamber is made to pass through the pinch roll gap clearance at one location, while an outlet side base plate running from the vacuum chamber towards the atmosphere is made to pass through the other pinch roll gap clearance, thereby an inlet side seal device and an outlet side seal device are integrated, that is, among the three pinch rolls in one set, through the gap clearance between the center pinch roll and one pinch roll on either side, a base plate running from the atmosphere side towards the vapor deposition chamber side is made to pass, while a base plate running reversely from the vacuum deposition chamber side towards the atmosphere side is made to pass through the gap clearance between the center pinch roll and the other pinch roll, a plurality of such sets of three pinch rolls are disposed as spaced from each other, and a reduced-pressure chamber is formed between adjacent ones of the similarly constructed sets of three pinch rolls; the number of pinch rolls is reduced, the distance of the pinch roll gap clearances is decreased as compared to the system shown in Fig. 9, hence the capacity of the evacuation system can be greatly reduced, and also a compact construction of the seal device can be realized. In addition, owing to the fact that the set of three pinch rolls forming seal device are arrayed in parallel on one plane, a load applied to the respective seal rolls by the pressure difference between two sub-chambers partitioned by the seal device acts in the direction perpendicular to the plane. Consequently, due to this load the pinch rolls would deform in parallel to each other in the direction perpendicular to the above-mentioned plane, hence the gap clearances between the pinch rolls and the gap clearances between the pinch rolls and the seal bars on the respective sides would not vary, and the initial values of the gap clearances can be maintained. Therefore, during the period when the base plate is made to pass through the gap clearances under an evacuated condition, the sealing performance would not vary, and the pressure within the chamber or sub-chamber partitioned by the seal device can be maintained stably. 2) According to another aspect of the present invention featured above, owing to the fact that deflector rolls are disposed between the adjacent sets of pinch rolls so that the base plate may be wrapped around the respective pinch rolls with a wrapping angle of 10 degrees or more, fluttering of the base plate caused by an airflow flowing through the gap clearances between the pinch rolls, can be prevented. 3) According to still another aspect of the present invention featured above, as a result of the fact that a wall is disposed between the cooling roll and the vapor deposition material container so as to surround the vapor evaporated from the container and the temperature of the wall is controlled in such manner that the inner surface faced to the vapor of the wall may be maintained at a temperature somewhat higher than the melting point of the vapor deposition material, the vapor deposition material other than the amount vapor-deposited onto the base plate is trapped by the wall and flows back into the vapor deposition material container in the form of liquid, so that a yield of the vapor deposition material can be greatly improved, and the problem that the vapor deposition material accumulates and interferes with the base plate such as a film, is also eliminated. In this connection, according to the results of experimental investigations, the yield of the vapor deposition material has been raised up to 90% or more. 4) According to a further aspect of the present invention featured above, edge masks are provided within the aforementioned wall so as to be slidable in the widthwise direction of the wall and the base plate, and the relative positioning of the edge masks with respect to the base plate is controlled in accordance with the width of the running base plate. That is, by continuously controlling the edge masks in position at such position that the edge masks may overlap by a minute amount with the opposite edge portions in the widthwise direction of the base plate, the vapor rising within the wall can be prevented from sputtering out exceeding the width of the base plate and depositing onto the cooling roll, and so, base plate having different widths can be continuously and stably subjected to vapor deposition. 5) According to still further aspects of the present invention featured above, the means for feeding a vapor deposition material is adapted to feed a vapor deposition material from the outside of a vacuum vapor deposition apparatus into a vapor deposition chamber. Accordingly, the vapor deposition material to be fed is placed on the outside of the apparatus, moreover a drive section for feeding the vapor deposition material into the vapor deposition chamber is also disposed on the outside of the apparatus, and members to be disposed inside of the apparatus could be those having a simple construction and being hardly damaged such as, for example, guide means for a vapor deposition metal (guide rolls, guide plates, etc.). Therefore, the vacuum vapor deposition apparatus would not become large-sized, and even if the vapor deposition material feed means should stop, the feed means only can be easily repaired without stopping the entire apparatus. 6) According to another aspect of the present invention featured above, since the vapor deposition material is wire-shaped, holes of a few millimeters in diameter are drilled in the respective seal bars in the reduced-pressure chamber, and the wire-shaped vapor deposition material placed on the outside is made to pass successively through these holes and thus can be fed to the vapor deposition chamber. In this feed means, if the gap clearance between the edge of the hole drilled in each seal bar and the wire-shaped vapor deposition material passing through this hole is made extremely small (of the order of 1/100 or less) as compared to the cross-section area of the gap clearances at the periphery of the above-described seal rolls, then a pressure rise caused by the gap clearance around the wire-shaped material becomes a negligible order, and so, the vapor deposition metal can be continuously fed while continuing the vacuum vapor deposition operation. 7) According to yet another aspect of the present invention featured above, continuous feeding of a base plate to a vacuum vapor deposition apparatus is made possible by rotatably mounting a pair of reels respectively on the inlet side and on the outlet side of the seal device, and disposing a coiler and an uncoiler provided with a press roll for sticking a base plate being paid out from or being wound around a pair of reels to another reel and a cutter for cutting a base plate being paid out from or being wound around the original reel after sticking. The above-mentioned and other objects, features and advantages of the present invention will become more apparent by reference to the following description of preferred embodiments of the invention taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS: In the accompanying drawings: Fig. 1 is a front view partly in cross-section showing a general construction of one preferred embodiment of the present invention; Fig. 2 is an enlarged partial cross-section view taken along line A-A in Fig. 1 as viewed in the direction of arrows; Fig. 3(A) is an enlarged front view of a pinch roll portion in the same preferred embodiment; Fig. 3(B) is a plan view of the same; Fig. 4(A) is a diagram showing a relation between a wrapping angle of a base plate around a pinch roll; Fig. 4(B) is a schematic view of a device employed to derive the relation shown in Fig. 4(A); Figs. 5 is a front view showing another preferred embodiment of the present invention; Fig. 6 is a front view showing one example of a continuous vapor deposition apparatus in the prior art; Fig. 7 is an enlarged partial cross-section view of the same continuous vapor deposition apparatus; Fig. 8 is an enlarged side view of the same apparatus taken along line XI-XI in Fig. 7 as viewed in the direction of arrows; and Fig. 9 is a front view showing another example of a vapor deposition apparatus of batch type in the prior art. DESCRIPTION OF THE PREFERRED EMBODIMENTS: Now one preferred embodiment of the present invention will be described with reference to Figs. 1 to 4. In Figs. 1 and 2, reference numerals 1 and 1' designate running base plate, numeral 2 designates a vapor deposition chamber, numeral 3 designates deflector rolls, numeral 4 designates a cooling roll, numeral 5 designates a take-up reel, numeral 6 designates a pay-out reel, numeral 7 designates a vapor deposition device numeral 8 designates a vapor deposition material, numeral 9 designates a vapor deposition material container, numeral 10 designates a heater, numeral 11 designates edge masks, numeral 14 designates a reduced-pressure chamber, numerals 15a, 15b and 15c, respectively, designate respective sets of three pinch rolls, numerals 16a, 16b and 16c, respectively designate reduced-pressure sub-chambers, numeral 17 designates a wall, numeral 18 designates a vapor deposition material charging port, numeral 19 designates an uncoiler, numeral 20 designates a coiler, numeral 21 designates a press roll, numeral 22 designates a cutter, numeral 23 designate a dam, numeral 24 designates a constant rate feeder, numeral 25 designates a receiving hopper, numeral 26 designates a feeding hopper, numeral 27 designates a valve, numeral 28 designates a vacuum pump, and numeral 29 designates an evacuation pump unit. In Fig. 1, a base plate 1 is mounted on a reel 6 of a pair of reels in the uncoiler 19, and fed to the reduced-pressure chamber 14 via deflector rolls 3a and the like. This reduced-pressure chamber 14 includes reduced-pressure sub-chambers 16a, 16b, 16c, ..... partitioned by a plurality of sets of three pinch rolls arrayed in parallel on one plane, which pinch roll sets are spaced from each other at a predetermined interval, by means of the evacuation pump unit 29 connected to the respective reduced-pressure chambers 16a, 16b and 16c a pressure gradient is generated from the atmosphere side up to the vapor deposition chamber 2, and thereby the vacuum deposition chamber 2 is maintained at a predetermined degree of vacuum. The base plate 1 successively passes through the roll gap clearances between two rolls on one side among the sets of three pinch rolls 15a, 15b and 15c, after it has been vapor-deposited on the cooling roll 4 by means of the vapor deposition device 7, again it runs reversely through the gap clearances between two pinch rolls on the opposite side among the sets of three pinch rolls 15a, 15b and 15c, and then it is delivered from the reduced-pressure chamber 14. The base plate 1 delivered into the atmosphere is taken up by a reel 5 of a pair of reels in a coiler 20 via deflector rolls 3b and the like. In order to continuously pay out and take up a base plate 1, another new base plate 1' is mounted on the other reel 6 in the uncoiler 19, after the base plate 1' has been accelerated and synchronized with the speed of the running base plate 1 by means of a drive unit not shown, it is pressed against the running base plate 1 by actuation of the press roll 21, and the respective base plates 1 and 1' are stuck with each other by means of a double-faced adhesive tape or the like mounted on the new base plate 1'. Furthermore, simultaneously with the sticking, the cutter 22 would cut the old base plate 1, and only the new base plate 1' is made to pass through the reduced-pressure chamber 14. With regard to the take-up operation also, likewise on the other reel 5 in the coiler 20 is stuck a double-faced adhesive tape or the like, and after the reel 5 has been synchronized with the running base plate 1, the base plate 1 is stuck with the reel 5 by means of the press roll 21, and the base plate 1 begins to be taken up by the new reel 5 by cutting the base plate 1 with the cutter 22 simultaneously with the sticking. On the other hand, vapor deposition is carried out in such manner that an evaporated vapor deposition material 8 passes through a passageway surrounded by the wall 17 disposed above the vapor deposition material container 9, further the expansion of the evaporated material in the widthwise direction of the base plate is limited by the edge masks 11 disposed at the above, and it reaches the base plate 1, as shown in Fig. 2. At this time, while the evaporated vapor deposition material 8 is also trapped by the edge masks 11 and the wall 17, it is returned into the vapor deposition material container 9 in the form of liquid because the inner surfaces of the respective members are held at a temperature higher than a melting point of the vapor deposition material due to radiation heat from the vapor deposition material container 9. In addition, on the outer circumference of the wall 17 shown in Figs. 1 and 2 is provided a cooling device 29a for externally feeding a coolant such as water or the like to regulate the temperature of the wall 17 so as to be maintained at a predetermined temperature. This predetermined temperature is a temperature that is a little higher than the melting point of the vapor deposition material 8, and in the case where the vapor deposition material 8 is aluminium, the wall 17 is regulated to be maintained at a temperature of about 900°C to 1000°C. In the illustrated embodiment, the vapor deposition material 8 within the vapor deposition material container 9 is aluminium, and this container 9 is heated at about 1400°C. The temperature regulation for the wall 17 by means of the above-described cooling device 29a is effected for the purpose of preventing excessive temperature rise caused by radiation heat from the side of the vapor deposition material container 9, and thus for the purpose of preventing adverse thermal effect upon the running base plate 1 consisting of a plastic film or the like of the excessive temperature rise, that is, for the purpose of preventing generation of thermal elongation of the base plate 1 (plastic film) and creases on the base plate 1. The above-described wall 17 is provided for the purpose of guiding the rising vapor evaporated from the vapor deposition material 8 to the base plate 1 wrapped around the cooling roll 4 without sputtering the rising vapor to the environment. The edge masks 11 shown in Fig. 2 are disposed as spaced at a certain interval in the widthwise direction of the base plate 1, and they are movable in the widthwise direction of the base plate 1 so that the vapor deposition apparatus can be adapted to change of the width of the base plate 1. The amount of the vapor deposition material 8 consumed by evaporation is fed by the vapor deposition material charging device shown in Fig. 2, which consists of the vapor deposition material receiving hopper 25, the valve 27, the feed hopper 26 and the constant rate feeder 24 such as a screw feeder or the like. More particularly, at first a predetermined amount of the vapor deposition material 8 is thrown into the receiving hopper 25, then after the interior of the receiving hopper 25 has been maintained at a predetermined degree of vacuum, the valve 27 is opened, and the vapor deposition material 8 within the receiving hopper 25 is transferred to the feed hopper 26. After the transfer, the valve 27 is closed, the vacuum pump 28 is stopped, and at the time point when the vapor deposition material 8 within the feed hopper 26 has been reduced to a lower limit amount, the above-described operations are repeated again. During this period, since the constant rate feeder 24 is continuously conveying the vapor deposition material 8, always a fixed amount of vapor deposition material 8 is surely maintained within the vapor deposition material container 9. It is to be noted that as a newly thrown vapor deposition material contains an impurity such as oxides or the like through very little, the impurity would be accumulated within the container resulting in the problem. that an evaporation rate is lowered, and therefore, provision is made such that the dam 23 is provided at one end portion of the container 9, and by throwing in the vapor deposition material 8 through the vapor deposition material throw-in port 18 provided on the outside of the dam 23, the impurity may be accumulated on the outside of the dam 23, while a high-impurity vapor deposition material may pass underside of the dam 23. Each of the seal rolls 15a, 15b, 15c, ..... shown in Fig. 1 is formed of one set of three pinch rolls 11', 12' and 13' as shown in Figs. 3(A) and 3(B), and the pinch rolls 11' and 13' are rotationally driven by a drive unit not shown. If the seal roll consisting of one set of three pinch rolls in the above-described manner is employed, since the total number of the leak gap clearances 19a - 19c is reduced as compared to the known structure in the prior art, the sum of the leak gap clearance cross-section areas can be decreased from a structural point of view, and so, a seal performance is improved. Furthermore, as shown in Figs. 3(A) and 3(B), the one set of three pinch rolls 11', 12' and 13' are arrayed in parallel on one plane between seal bars 140 on the respective sides, and the seal bars 140 on the respective sides are positioned on the same one plane with small gap clearances 19a spaced from the pinch rolls and fixedly secured to a casing 160. Therefore, during evacuation by the evacuation pump unit 29 in Fig. 1, a pressure difference would arise between the before and behind of the seal device, and hence a load applied to the pinch rolls due to the pressure difference would act in the direction perpendicular to the aforementioned one plane. Accordingly, bending deformation of the pinch rolls caused by load would arise while being held in parallel to the plane of the seal bars and while maintaining the initial gap clearances 19a, so that a seal performance would not vary during the pass of the base plate in vacuum and a predetermined pressure can be stably maintained within the respective reduced-pressure sub-chambers. Moreover, since the base plate always pass through the gap between the pinch rolls, and since the base plate is guided by the pinch rolls rotating at the substantially the same peripheral speed as the running speed of the base plate, even when a double-layer portion corresponding to a spliced portion of base plate passes through the seal device, or even when the base plate passes through the seal device while momentarily floating up from the pinch roll due to tension variations, generation of scratches on the base plate or breaking of the base plate would not occur. In addition, as shown in Fig. 1, a wrapping angle of the base plate 1 around the pinch roll is insured to be 10° or larger by means of a pair of deflector rolls 3 provided between the adjacent pinch roll pairs (that is, within the respective reduced-pressure sub-chambers 6a, 6b, 6c, ......), and so, even if a leak gas should be generated, fluttering of the running base plate 1 caused by the leak gas would be extremely little. According to experiments conducted by the inventors of this invention, as shown in Fig. 4(A), this wrapping angle is appropriate when it is 10° or larger, and if the base plate is wrapped around the pinch roll with a wrapping angle of 10° or larger, fluttering of the base plate would become no issue. It is to be noted that the data shown in Fig. 4(A) were obtained as a result of experiments conducted in essence as shown in Fig. 4(B). More particularly, in Fig. 4(B) between a seal roll 101 of 80 mm in diameter and a seal roll 102 of 90 mm in diameter, is made to run each of two films (running base plates) 1 having a width of 400 mm and thicknesses of 12 µm and 20 µm, respectively. Then, a guide roll 103 within a vacuum chamber 105 and a guide roll 104 within the atmosphere were moved along arcs indicated by double-headed arrows α to vary a wrapping angle of the film 1 around the seal roll 102, and a fluttering state (an amplitude of fluttering) of the film 1 at the portions encircled by dash lines β was visually evaluated. At this time, the interior of the vacuum chamber 105 was evacuated in the direction of an arrow γ by means of a vacuum pump and the pressure in the vacuum chamber 105 was adjusted to 47 996 Pa (360 Torr) so that the pressures at the before and behind the pinch rolls 101 and 102 may become the atmospheric pressure and 47 996 Pa (360 Torr), respectively, which are the most severe conditions for fluttering of the film, where a flow rate of the gas passing between the pinch rolls 101 and 102 becomes the maximum. According to the illustrated embodiment of the present invention, the following advantages were obtained: (1) By constructing a vapor deposition material container as an integral container extending in the width-wise direction of the base plate, an evaporation surface becomes continuous in the widthwise direction, distribution of a thickness of a vapor deposition film deposited on the base plate becomes uniform, furthermore the distribution state would not vary even if the edge masks are displaced at the above of the container in accordance with a width of a base plate, and therefore, continuous vapor deposition can be effected stably. (2) By providing a dam at one end portion of the vapor deposition material container and disposing a vapor deposition material throw-in port on the outside of the dam, in other words, by partitioning the upper layer of the vapor deposition material in a molten state as heated within the container by means of a dam so that the molten vapor deposition material can communicate through a bottom portion and continuously feeding a new vapor deposition material through a vapor deposition material throw-in port disposed above the partitioned outside portion of the molten vapor deposition material, the problem that oxides or the like contained in the vapor deposition material may enter the partitioned inside portion and may be accumulated on the surface of the molten vapor deposition material, resulting in deterioration of an evaporation performance, can be prevented. (3) A vacuum vapor deposition material is once thrown into the receiving hopper, and after the interior of the receiving hopper has been maintained at a predetermined degree of vacuum by means of a separately equipped vacuum pump, the material is stored in a feed hopper at the lower level by opening a valve at the below, and the material is continuously fed from the feed hopper and continuously thrown into the throw-in port above the vapor deposition material container as controlled to a feed rate matched with the evaporation rate by means of a feeder such as a screw feeder. At the time point when the vapor deposition material within the feed hopper has reached its lower limit value, the valve at the below of the receiving hopper is closed, and then by repeating the pattern of throwing a new vapor deposition material into the receiving hopper, it becomes possible to throw in a vapor deposition material while it is sealed from the atmosphere. In still another preferred embodiment shown in Fig. 5, a continuous vacuum vapor deposition system is constructed and operated in the following manner. A plastic film (base plate) 1 paid out of a device for paying out a coiled film (not shown) passes through a gap between pinch rolls 02 and 02' at an inlet of a continuous vacuum seal apparatus A consisting of reduced-pressure sub-chambers a - e , then enters into a first stage reduced-pressure sub-chamber a , subsequently passes through a gap between pinch rolls 03 and 03' at an inlet of a second-stage sub-chamber b , enters the second-stage reduced-pressure sub-chamber b , then successively passes through the gaps between pinch rolls 04 and 04', between pinch rolls 05 and 05', between pinch rolls 06 and 06', and between pinch rolls 07 and 07' to thus pass through the reduced-pressure sub-chambers c - e , eventually it is led to a vapor deposition chamber f , after vapor of aluminium 010 molten in a crucible 09 has been deposited onto the base plate under a cooling roll 08, the base plate 1 is again led into the above-described continuous vacuum seal apparatus A, then inversely to the above-mentioned inlet side route, it passes successively through the gaps between pinch rolls 07' and 07'', between pinch rolls 06' and 06'', between pinch rolls 05' and 05'', between pinch rolls 04' and 04'', between pinch rolls 03' and 03'' and between pinch rolls 02' and 02'' to thus pass through the fifth to first stages of reduced-pressure sub-chambers e - a , then it is delivered into the atmosphere, and the base plate is taken up by a take-up device not shown. It is to be noted that once vapor deposition for one coil of film has been finished, the coiled film is successively exchanged by means of continuous exchanging devices not shown provided in the pay-out section and in the take-up section, respectively, in the continuous vapor deposition system, hence they are successively vapor-deposited without interruption, and the system can be operated continuously over 300 hours or more. Here, it is to be noted that the above-described continuous vacuum seal apparatus A is composed of a plurality of seal bars 02''', 03''', 04''', 05''', 06''' and 07''', a plurality of reduced-pressure sub-chambers a , b , c , d and e , a vapor deposition chamber f , and vacuum pumps I, II, III, IV, V and VI for evacuating the respective reduced-pressure sub-chambers a - e and the vapor deposition chamber f , respectively, and the apparatus A is operated in such manner that air flowing in through the gap clearances between the pinch rolls themselves and between the pinch rolls and the seal bars may be evacuated continuously, and the pressures within the respective sub-chambers a - f may be respectively held at vacuum pressures successively lowered up to high vacuum from the atmosphere towards the vapor-deposition chamber as shown in the example of practical data enumerated in the below. First stage vacuum sub-chamber a : 53329 Pa (400 Torr) Second stage vacuum sub-chamber b : 19998 Pa (150 Torr) Third stage vacuum sub-chamber c : 6666 Pa (50 Torr) Fourth stage vacuum sub-chamber d : 666.6 Pa (5 Torr) Fifth stage vacuum sub-chamber e : 133.322 x 10⁻² Pa (1 x 10⁻² Torr) Vapor deposition chamber f : 133.322 x 10⁻⁴ Pa (1 x 10⁻⁴ Torr) The above-described pinch rolls 02, 02', 02'', 03, 03', 03'', ....., 07, 07' and 07'' form six sets each consisting of three pinch rolls, and each of the respective sets of three pinch rolls 02, 02' and 02''; 03, 03' and 03''; .....; 07, 07' and 07'' are arrayed in parallel on one plane perpendicular to the plane of the plastic film 1 passing through the gap clearances between adjacent pinch rolls. In addition, under the above-mentioned cooling roll 08 is disposed a crucible 09 for melting aluminium 010, and this crucible 09 is heated by heater means such as, for example, a high frequency induction heating apparatus (not shown). By the way, normally a consumption rate of aluminium is about 1 kg/h, and an aluminium storage amount of the crucible 09 is of the order of about 10 kg. Accordingly, once aluminium has been charged in the crucible 09, the system is operable for about 8 - 9 hours without supplementing aluminium, but if the operation prolongs for a longer period than the above-mentioned period, it is necessary to supplement aluminium by aluminium feed means according to the present invention, which is constructed, for instance, in the following manner. More particularly, the aluminium feed means is constructed in such manner that holes x ₁, x ₂, x ₃, x ₄, x ₅ and x ₆ for making an aluminium wire 011 pass therethrough are formed in the seal bars 02''', 03''', 04''', 05''', 06''' and 07''', respectively, which partition the above-described respective reduced-pressure sub-chambers a - e , the aluminium wire 011 is made to pass through these holes in the same direction as the direction of passing of the plastic film 1, and the aluminium wire can be fed into the crucible 09 by means of a continuous feeder 011' for the aluminium wire 011 provided in the atmosphere, a guide roll 012, and a feed roll 013 driven by a drive unit not shown. In this connection, the gap clearances between the aluminium wire 011 and the holes x ₁ - x ₆ are preset so as to be a few millimeters or less to reduce a flow rate of air leaking through these gap clearances to a sufficiently negligible mount. As shown in Fig. 7, within the vapor deposition chamber f are also disposed guide rolls 012', guide plates 012'' and guide rolls 013 for the aluminium wire 011. The above-described aluminium feed means employed in the illustrated embodiment is intermittently operated, for instance, about every 8 - 9 hours as described above, and during the operation stop period, the tip end of the aluminium wire 011 is positioned above and in the proximity of the surface of the molten aluminium 010, but the other portion (the portion other than the tip end portion) is held to be positioned between the guide plates 012'', between the guide rolls 012' and within the holes x ₆ - x ₁. Even during this operation stop period, the gap clearances between the aluminium wire 011 and the holes x ₁ - x ₆ are sufficiently small, hence the flow rate of air leaking through the gap clearances can be disregarded, and vapor deposition can be favorably continued. As will be apparent from the preceding detailed description of the preferred embodiments of the present invention, according to the present invention the following effects and advantages are obtained: (1) In the vacuum vapor deposition apparatus according to the present invention, since the leak gap clearances in the seal roll section can be maintained to be small, a sealing performance is improved. (2) In addition, in the vacuum vapor deposition apparatus according to the present invention, since the base plate is wrapped around the seal roll with a wrapping angle of 10 degrees or more, even if a little leak gas should present, fluttering of the running base plate is eliminated, and there is no fear that creases may be generated in the running base plate nor the running base plate may be broken. (3) According to the present invention, it has become possible to continuously carry out vapor deposition onto a paper sheet or a plastic film which could be carried out only in a batch system in the prior art, hence the rate of operation is greatly improved, and a production cost can be reduced to 1/2 to 1/3 of that in the prior art. In the case of a batch system, even in many-variety small-lot production similar batch works must be carried out repeatedly and hence the rate of operation of the system is poor, whereas according to the present invention a small lot and large lot can be continuously vapor-deposited by splicing, hence further improvement in the rate of operation can be expected, and also schedule-freeing of production is possible. Furthermore, contribution to the improvements in maneuverability and easiness of maintenance such that since the film is taken up in the atmosphere, instruments can be easily equipped, quality control is easy, a yield of a vapor deposition material is high, and saying on the contrary, a work of removing vapor deposition materials deposited within an equipment can be reduced, can be expected. (4) If the vacuum vapor deposition apparatus according to the present invention is employed, a far larger amount of base plates to be vapor-deposited (for instance, 300 times as large as the amount in the prior art) can be continuously subjected to metal vapor deposition than that was vapor-deposited by the system in the prior art. (5) In addition, if the vapor deposition metal feed means in the vacuum vapor deposition apparatus according to the present invention as claimed in the appended Claim 3 is employed, since the gap clearance cross-section area between the vapor deposition metal wire made of aluminium or the like and the hole is about 1/100 times as small as the gap clearance cross-section area between the seal rolls or between the seal roll and the seal bar, a leaking rate of air can be well disregarded, and the pressure within the vacuum vapor deposition chamber can be maintained within a pressure range where vacuum vapor deposition is possible. Accordingly, continuous feeding of vapor deposition metal such as aluminium or the like during continuation of vacuum vapor deposition becomes possible, and vacuum vapor deposition can be carried out continuously over a long period of time.

Claims: A continuous vacuum vapor deposition apparatus wherein a base plate (1,1') is continuously fed from the atmosphere, made to pass through a reduced-pressure chamber (14), wrapped around a cooling roll (4) at an upper portion within a vapor deposition chamber (2), then subjected to vacuum vapor deposition by means of vapor rising from a vapor deposition material container (9) at a lower portion within said vapor deposition chamber (2), again made to pass through said reduced-pressure chamber (14), and continuously delivered into the atmosphere; characterized in that in said reduced-pressure chamber (14), the space between the atmosphere and said vapor deposition chamber (2) is partitioned into a plurality of sub-chambers (16a-c) by means of seal devices, each said seal device includes one set of three pinch rolls (15a-c) arrayed in parallel on one plane and a pair of seal bars (140) positioned on said one plane on the respective sides of the pinch roll set (15a-c) with small gap clearances (19a-c) spaced from the pinch rolls, the gap clearances between the center roll and the rolls on the respective sides in said pinch roll set (19a-c) are adapted to make the base plate portions (1) on the inlet side and on the outlet side respectively pass therethrough, in each said reduced-pressure sub-chamber (16a-c) are disposed a pair of deflector rolls (3) so that the base plate portions (1) on the inlet side and on the outlet side may be wrapped respectively around said pinch rolls (15a-c) with a wrapping angle of 10 degrees or more, and further, a temperature-adjustable wall (17) surrounding a rising vapor passageway is disposed between said cooling roll (4) and said vapor deposition material container (9). A continuous vacuum vapor deposition apparatus as claimed in Claim 1, characterized in that edge masks (17) which are movable in the widthwise direction of the base plate are provided between said cooling roll (4) and an upper portion of said wall (17). A continuous vacuum vapor deposition apparatus, wherein a base plate (1) is continuously fed from the atmosphere, made to pass through a reduced-pressure chamber, wrapped around a cooling roll (08) at an upper portion within a vapor deposition chamber (f), then subjected to vacuum vapor deposition by means of vapor rising from a vapor deposition material container at a lower portion within said vapor deposition chamber (f), again made to pass through said reduced-pressure chamber, and continuously delivered into the atmosphere; characterized in that in said reduced-pressure chamber, the space between the atmosphere and said vapor deposition chamber (f) is partitioned into a plurality of sub-chambers (a-e) by means of seal devices, each said seal device includes one set of three pinch rolls (02-07) arrayed in parallel on one plane and a pair of seal bars (02'''-07''') positioned on said one plane on the respective sides of the pinch roll set with small gap clearances spaced from the pinch rolls, the gap clearances between the center roll and the rolls on the respective sides in said pinch roll set are adapted to make the base plate portions on the inlet side and on the outlet side respectively pass therethrough, and there is provided means for feeding a wire-shaped vapor deposition material (011) from the atmosphere through the respective reduced-pressure sub-chambers (a-e) into the vapor deposition material container within said vapor deposition chamber (f), whereby said wire-shaped vapor deposition material (011) passes through holes (x₁-x₆) in said seal bars (02'''-07''') and the gap clearance between the edge of said hole in each seal bar and the wire-shaped deposition material passing through this hole is of the order of 1/100 or less as compared to the cross-section area of the gap clearance of the periphery of said seal rolls. A continuous vacuum vapor deposition apparatus, wherein a base plate (1) is continuously fed from the atmosphere, made to pass through a reduced-pressure chamber (14), wrapped around a cooling roll (4) at an upper portion within a vapor deposition chamber (2), then subjected to vacuum vapor deposition by means of vapor rising from a vapor deposition material container (9) at a lower portion within said vacuum vapor deposition chamber (2), again made to pass through said reduced-pressure chamber (14), and continuously delivered into the atmosphere; characterized in that in said reduced-pressure chamber (14), the space between the atmosphere and said vapor deposition chamber (2) is partitioned into a plurality of sub-chambers (16a-c) by means of seal devices, each said seal device includes one set of three pinch rolls (15a-c) arrayed in parallel on one plane and a pair of seal bars (140) positioned on said one plane on the respective sides of the pinch roll set with small gap clearances (19a-c) spaced from the pinch rolls, the gap clearances between the center roll and the rolls on the respective sides in said pinch roll set are adapted to make the base plate portions on the inlet side and on the outlet side respectively pass therethrough, and there is provided a vapor deposition material charging device for feeding a granular vapor deposition material (8) from the atmosphere into the vapor deposition material container (9) within said vapor deposition chamber (2), whereby said vapor deposition material charging device comprises a hopper (25) adapted to be closed, a valve (27) capable of shutting an interval between said hopper (25) and said vapor deposition chamber (2) and a vacuum pump (28) for evacuating said interval. A continuous vacuum vapor deposition apparatus as claimed in Claim 1, characterized in that there are provided an uncoiler (19) for continuously feeding the base plate (1,1') into said reduced-pressure chamber (14), which is associated with means for cutting and splicing the base plate (1,1'), and a coiler (20) for continuously taking out the base plate (1,1') from said reduced-pressure chamber (14), which is associated with means for cutting and splicing the base plate (1,1').

Inventors: FURUKAWA HEIZABURO HIROSHIMA M, KAMIKAWA SUSUMU HIROSHIMA MACH, OKITA HAJIME HIROSHIMA TECHN I, TAGUCHI TOSHIO HIROSHIMA TECHN, YANAGI KENICHI HIROSHIMA TECHN, FURUKAWA, HEIZABURO HIROSHIMA MACH. W. MITSUBISHI, KAMIKAWA, SUSUMU HIROSHIMA MACH. W. MITSUBISHI, OKITA, HAJIME HIROSHIMA TECHN. INST. MITSUBISHI, TAGUCHI, TOSHIO HIROSHIMA TECHN. INST. MITSUBISHI, YANAGI, KENICHI HIROSHIMA TECHN. INST. MITSUBISHI
Applicants: MITSUBISHI HEAVY IND LTD, MITSUBISHI JUKOGYO KABUSHIKI KAISHA
Application year: 1989
Main classification: C23C14
IPC codes: F16J15, C23C14