JP5803102B2 - Laminate sheet manufacturing apparatus and method - Google Patents

Description

  The present invention relates to an apparatus and a method for manufacturing a laminated sheet.

  Multiple types of molten material are supplied to each manifold that receives each molten material, and the molten material flows out of each manifold through multiple pores and multiple slits to form a laminar flow of multiple molten materials. A multi-layered molten material sheet is formed by combining a plurality of types of molten material, and the sheet is formed into a slit-shaped base that extends in a direction (sheet width direction) perpendicular to the stacking direction of the layers of the molten material. There is known a method of forming a laminated sheet by discharging from a sheet (for example, Patent Document 1 and Patent Document 2). The laminated sheet discharged from the die is used as it is or after that, after being subjected to post-treatment such as stretching.

  A typical example of this laminated sheet manufacturing apparatus is shown in FIG. In FIG. 1, the laminated sheet manufacturing apparatus is supplied by a molten material introduction tube 1 to which one molten material A is supplied, a molten material introduction tube 2 to which the other molten material B is supplied, and a molten material introduction tube 1. A multilayer feed block 3 that forms a laminated flow composed of the molten material A and the molten material B supplied by the molten material introduction pipe 2, a conduit 4 through which the formed laminated flow flows, and the width and thickness of the laminated flow supplied by the conduit 4 Is adjusted to a predetermined value, and the adjusted laminated flow is discharged to form a laminated sheet in which the molten material A and the molten material B are alternately laminated, and the laminated sheet 6 discharged from the die 5 It consists of a casting drum 7 that cools and solidifies. The laminated sheet solidified by the casting drum 7 is usually called an unstretched film 8. The unstretched film 8 is usually sent to a stretching process (not shown) as indicated by an arrow NS and stretched in one direction or two directions to form a multilayer film.

  The multilayer feed block 3 has passed through each of the slits, a manifold coupled to the molten material introduction tube 1, a manifold coupled to the molten material introduction tube 2, and a plurality of slits arranged at predetermined intervals. It has a confluence | merging part which merges the flow of each molten material. The plurality of slits are divided into two groups, the plurality of slits in one group open to the outlet of the manifold coupled to the molten material introduction pipe 1, and the plurality of slits in the other group are introduced into the molten material Opening to the outlet of the manifold coupled to the tube 2. The outlet of the junction is communicated with the conduit 4.

  In general, a material having a high refractive index and a material having a low refractive index are respectively supplied to the molten material introduction tube 1 and the molten material introduction tube 2, and each material is alternately laminated with a certain thickness so that a specific wavelength is obtained. Films that reflect light and films that reflect or transmit light in a wide wavelength range by laminating the layers of each material layer by sequentially decreasing or increasing the thickness of each layer at a certain rate in the film thickness direction. It is known to be obtained.

  According to the knowledge of the present inventor, it is important to increase the laminating accuracy in order to obtain such a film, but when a multilayer film was formed using the above-mentioned multilayer feed block, the slit portion of the multilayer feed block was It has been found that the thickness of each layer in the film width direction is not uniform due to the difference in the path length of the molten material flowing through the film, and that the wavelength of light reflected or transmitted in the film width direction is different.

  Patent Document 3 is proposed by the present inventor as a method for solving the above problem. An example of the multilayer feed block used in the laminated sheet manufacturing apparatus is shown in FIG. In FIG. 9, the manifold formed in the multilayer feed block and the space portion of the slit portion are shown.

  In FIG. 9, a multilayer feed block 101 is provided with a material introduction path 102 for introducing the molten material A into the block 101 and a material introduction path 103 for introducing the molten material B into the block. In the multilayer feed block 101, a manifold 104 to which the material introduction path 102 is coupled and a manifold 105 to which the material introduction path 103 is coupled are provided. The manifold 104 guides the flow of the molten material A introduced from the material introduction path 102 over the entire width of the multilayer feed block 101 in the stacking direction (X-axis direction shown in FIG. 9). The manifold 105 guides the flow of the molten material B introduced from the material introduction path 103 over the entire width of the multilayer feed block 101 in the stacking direction (X-axis direction shown in FIG. 9).

  Furthermore, a large number of slits arranged at a predetermined interval 108 are provided in the multilayer feed block 101. The large number of slits includes a slit group including a plurality of slits 106 and a slit group including a plurality of slits 107. The slits 106 and the slits 107 are alternately arranged with an interval 108 therebetween. The upstream ends of the slits 106 and 107 in the slit passing direction (Z-axis direction shown in FIG. 9) are inclined in opposite directions, and the inlets of the slits 106 are coupled to the manifold 104. The entrance of each slit 107 is coupled to the manifold 105. That is, a slit group including a plurality of slits 106 communicates with the manifold 104, and a slit group including a plurality of slits 107 communicates with the manifold 105.

  Furthermore, a merging portion (not shown) coupled to the exit portions of the slits 106 and the slits 107 is provided inside the multilayer feed block 101. In this merging portion, a molten material A flow that flows out from the exit portion of each slit 106 and a flow of molten material B that flows out from the exit portion of each slit 107 forms a laminated flow of molten material. The

  FIG. 10 shows a slit of the multilayer feed block 101. In the middle of the slit passage direction of the slit 106 and the slit 107, a narrow portion 109 having a narrow slit gap (dimension in the X-axis direction shown in FIG. 10) is provided in the entire area in the slit width direction D. Since the flow of the molten material flowing in from the narrow portion 109 is regulated in the slit width direction by the narrow portion 109 and widened in the slit width direction, the flow rate of the molten material flowing through the narrow portion is made uniform in the slit width direction. The flow rate of the molten material becomes uniform.

  Further, the slits 106 and 107 and the narrow portion 109 formed on the slit plate are manufactured so that the slit gap is the same over the entire width in the slit width direction.

  However, the multilayer feed block proposed by the present inventor has improved the thickness uniformity of each layer in the width direction as compared with the prior art, but the slit gap in the narrow part is small, so that the flow rate of the molten material is high or the melting When the viscosity of the material is high, the pressure loss at the narrow part becomes too large, and the slit deforms due to the pressure, the original slit gap cannot be maintained, and the flow rate of the material flowing through the slit changes, resulting in a uniform film width direction. The case where it does not laminate | stack with a sufficient layer thickness occurs. In addition, since the gap in the narrow portion is small, there is a problem that the flow rate flowing through the slit changes with a slight error in processing, or the slit gap in the narrow portion is small and difficult to process.

  In FIG. 10, the series of slits 106 involved in the flow of the molten material A and the series of slits 107 involved in the flow of the molten material B are shown in the same direction, but can be understood with reference to FIG. Thus, in practice, one series has a left-right inverted relationship with respect to the other series.

Japanese Patent Publication No. 50-6860 JP 2003-112355 A JP 2010-137448 A

  The subject of this invention is providing the manufacturing apparatus and manufacturing method of a laminated sheet which can manufacture the laminated sheet in which the thickness of each layer in the width direction of a laminated sheet is substantially uniform in order to solve the above-mentioned problem. .

  In order to achieve the above object, the laminated sheet manufacturing apparatus of the present invention has the following configuration.

  That is, a laminated sheet manufacturing apparatus for laminating a plurality of types of molten materials so as to form a layer having a larger number of layers than the number of the types, and a plurality of first manifolds that respectively supply the molten materials, A plurality of slits communicating with any one of the first manifolds and allowing the molten material supplied in the first manifolds to pass from the first manifolds in the slit passing direction corresponding to the layers; Each melting material that has passed through the plurality of slits is joined together while overlapping in the stacking direction orthogonal to the slit passing direction, and each slit that communicates with any of the plurality of first manifolds, A second manifold having a larger dimension in the stacking direction than a slit gap of each slit at a portion communicating with the first manifold of each slit. Field production apparatus of a laminated sheet, characterized in that provided on all of the slit width direction is provided.

  By providing the second manifold in all the width direction of the slit in the portion communicating with the first manifold of the slit, it becomes easy for the molten material to flow to the slit in the portion far from the first manifold, and far from the side near the first manifold of the slit. By reducing the flow rate difference on the side, the flow rate of the molten material in the slit width direction becomes uniform.

  According to a preferred embodiment of the present invention, when the slit gaps of the plurality of slits are S and the maximum dimension in the stacking direction of the second manifold is T, the following expression (1) is satisfied. An apparatus for manufacturing a laminated sheet is provided.

2.5S ≦ T ≦ 5S Formula (1)
When the maximum dimension T in the stacking direction of the second manifold is less than 2.5 times the slit gap S, the molten material is not sufficiently widened in the slit width direction, resulting in nonuniform thickness of each layer in the width direction. May end up. Further, when the maximum dimension T in the stacking direction of the second manifold is larger than five times the slit gap S, the dimension in the stacking direction of the second manifold becomes too large, and the apparatus becomes large when the number of stacks increases. In addition, if the second manifold is large, depending on the type of molten material, stagnation may occur and the material may be thermally deteriorated, which may adversely affect film quality.

  Moreover, according to the preferable form of this invention, the said 2nd manifold inclines in the downstream direction as it leaves | separates from a 1st manifold, The laminated sheet manufacturing apparatus characterized by the above-mentioned is provided. By tilting the second manifold, the first manifold to be communicated can be selected with a simple structure. In addition, the path difference of the molten material between the side closer to the first manifold and the side far from the first manifold is reduced, and the slit width is further reduced. Directional flow distribution is improved.

  According to a preferred embodiment of the present invention, there is provided a laminated sheet manufacturing apparatus characterized in that the cross-sectional area of the second manifold decreases as the distance from the first manifold increases. By reducing the cross-sectional area of the second manifold as it moves away from the first manifold, the decrease in the flow rate of the molten material flowing in the second manifold is prevented, so that the residence time of the molten material flowing through the slit portion close to the first manifold and the first The difference in the residence time of the molten material flowing through the slit portion far from the one manifold can be reduced, and the residence portion of the molten material generated in the portion of the second manifold farthest from the first manifold can be reduced.

  Moreover, according to the preferable form of this invention, the said each slit is laminated | stacked radially and the laminated sheet manufacturing apparatus characterized by the above-mentioned is provided. When the second manifold is provided in the slit, the distance between the adjacent slits is required, and the dimension of the multilayer feed block in the stacking direction increases. However, the dimension can be reduced by arranging the slits in a radial stack. Moreover, the thickness of the partition existing between the slits is thicker in the upstream portion than the downstream of the slit, and the strength of the partition is maintained even if the second manifold is provided.

  Moreover, according to the preferable form of this invention, the slit gap | interval of each said slit is gradually enlarged toward the merge part in the vicinity of a merge part, The laminated sheet manufacturing apparatus characterized by the above-mentioned is provided. By gradually increasing the slit gap in the vicinity of the junction, the thickness of the partition existing between the slits can be reduced, and the junction of the molten materials flowing out of the slit can be stabilized. It is possible to prevent turbulence at the time of merging and reduce the stay at the tip of the partition wall.

  Further, according to a preferred embodiment of the present invention, the slit gap of each of the slits changes stepwise or continuously from one end of the slit excluding the slit at the endmost portion in the stacking direction to the other end. An apparatus for producing a laminated sheet is provided.

  By changing the slit gap of each slit except the outermost part stepwise or continuously from one end to the other in the stacking direction, the thickness of the gradient structure gradually changes in the thickness direction of the film excluding the surface layer. A film can be obtained.

  Moreover, according to the preferable form of this invention, the dimension D of the said slit width direction is 20 mm or more and 100 mm or less, The manufacturing apparatus of the lamination sheet characterized by the above-mentioned is provided.

  If the dimension D in the slit width direction is less than 20 mm, the strength of the slit forming part may be insufficient, and if the slit width exceeds 100 mm, it becomes difficult to process the slit with high accuracy, and thereby uniformity in the width direction. Is damaged.

  According to a preferred embodiment of the present invention, there is provided a laminated sheet manufacturing apparatus, wherein a plurality of material introduction ports for supplying each molten material to each first manifold are provided. .

  By providing a plurality of material introduction ports for supplying the molten material to the first manifold, the molten material can be uniformly supplied to the slits even when the number of slits is large.

  Further, according to another aspect of the present invention, there is provided a method for manufacturing a laminated sheet in which a plurality of types of molten materials are laminated so as to form a layer having a number of layers larger than the number of the types. Via the plurality of first manifolds, communicate with any one of the first manifolds, and supply the plurality of slits to pass in the slit passing direction corresponding to each layer, and the plurality of slits supplied to the plurality of slits When merging each molten material while overlapping each other in the stacking direction orthogonal to the slit passing direction, each slit communicating with one of the plurality of first manifolds is formed in a portion communicating with the first manifold of each slit. The second manifold having a larger dimension in the stacking direction than the slit gap of each of the slits is a slit provided in all of the slit width directions. Method for producing a laminated sheet, wherein the door is provided.

  In the present invention, the molten material is, for example, a polyolefin resin such as polyethylene, polypropylene, polystyrene, or polymethylpentene, an alicyclic polyolefin resin, a polyamide resin such as nylon 6 or nylon 66, an aramid resin, polyethylene terephthalate, or polybutylene terephthalate.・ Polypropylene terephthalate ・ Polybutyl succinate ・ Polyester resin such as polyethylene-2,6-naphthalate, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluoroethylene resin, trifluoride Fluorine resin such as ethylene chloride resin, ethylene tetrafluoride-6-fluoropropylene copolymer, vinylidene fluoride resin, acrylic resin, methacrylic resin, poly Tar resins, can be used polyglycolic acid resin, polylactic acid resin, and the like. Further, these thermoplastic resins may be homo resins, copolymerized or blends of two or more. Also, in each thermoplastic resin, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, thickeners, thermal stabilizers, lubricants, infrared absorbers, ultraviolet absorbers. An agent, a dopant for adjusting the refractive index, and the like may be added.

  According to the laminated sheet manufacturing apparatus of the present invention, it is possible to easily produce a laminated sheet in which the thickness of each layer is substantially uniform in the width direction.

The perspective view for demonstrating the manufacturing apparatus and manufacturing process of the lamination sheet which are generally used and are used also as embodiment of this invention. The disassembled perspective view of an example of the multilayer feed block used in the manufacturing apparatus of the lamination sheet of embodiment of this invention. The front view of the slit board in the multilayer feed block of embodiment of this invention of FIG. 2, and a confluence | merging and a discharge path. The S1-S1 cross section arrow directional view in FIG. The perspective view of the slit in Fig.4 (a). The S2-S2 cross-sectional arrow view in FIG. The perspective view of the slit in Fig.5 (a). FIG. 3 is a diagram for explaining the dimensional relationship of slits used in Example 1. The figure explaining the dimension of the slit gap | interval in Fig.6 (a). The figure explaining each dimensional relationship of the slit used in the comparative example 1. FIG. The figure explaining the dimension of the slit gap | interval in Fig.7 (a). The figure explaining each dimensional relationship of the slit used in the comparative example 2. FIG. The figure explaining the dimension of the slit gap | interval in Fig.8 (a). The perspective view which shows the internal space (flow path of a molten material) of the multilayer feed block used for the manufacturing apparatus of the conventional laminated sheet. The figure explaining the flow path of the molten material in the slit of the conventional multilayer feed block shown in FIG. The schematic cross section of the lamination sheet obtained using the manufacturing apparatus of the lamination sheet of this invention.

  2 to 5 are views relating to the multilayer feed block 3 used in an embodiment of the laminated sheet manufacturing apparatus of the present invention. 2 is an exploded perspective view of the multilayer feed block 3, and FIG. 3 is a front view of the slit plate 20 and the junction / discharge path forming member 20a of FIG.

  In FIG. 2, the multilayer feed block 3 has a side plate 21, a side plate 22, and a slit plate 20 sandwiched between the side plate 21 and the side plate 22. The slit plate 20 has a merging portion 18 and a discharge path 19 at the lower portion thereof.

  The side plate 21 is provided with a first manifold 14 on the side of the molten material A that extends in the stacking direction (a sector-shaped circumferential direction in which slits are formed in the XZ plane of FIG. 2), and the first manifold 14 is in a molten state. A plurality of molten material introduction paths 12 for supplying the material A (molten material A) into the first manifold 14 are coupled. The side plate 22 is provided with a first manifold 15 on the side of the molten material B that extends in the stacking direction (a sector-shaped circumferential direction in which slits are formed in the XZ plane of FIG. 2), and the first manifold 15 is in a molten state. A plurality of molten material introduction paths 13 for supplying the material B (molten material B) into the first manifold 15 are coupled.

  As shown in FIG. 3, the slit plate 20 has a large number of slits 16 and a large number of slits 17 radially in the stacking direction (a sector-shaped circumferential direction in which slits are formed in the XZ plane of FIG. 3). 20a is provided. The slits 16 and the slits 17 are alternately located via the partition walls 20a. A second manifold 16 a having a larger dimension in the stacking direction than a slit gap of each slit 16 is formed at a portion in contact with the first manifold 14 at an upper portion of each slit 16, and each slit is formed at a portion in contact with the first manifold 15 at an upper portion of each slit 17. A second manifold 17a having a larger dimension in the stacking direction than 17 slit gaps is provided in the entire width of each slit (Y direction perpendicular to the paper surface of FIG. 3). Each of the slits 16 and 17 is carved into the slit plate 20 with a predetermined length in a radial pattern around a certain point of the slit plate 20. Both side surfaces of the slits 16, 17 and the second manifolds 16 a, 17 a are open to both side surfaces of the slit plate 20. In the present embodiment, the slits 16 and 17 are arranged in a radial manner. However, as shown in FIG. 9, a configuration in which the second manifold is provided in the slit of a conventional multilayer feed block having a configuration in which the slits are arranged in parallel in the stacking direction. Anyway.

  The slit 16 and the second manifold 16a, and the slit 17 and the second manifold 17a are inclined in opposite directions to each other in the slit width direction (Y direction perpendicular to the paper surface of FIG. 3), and the side plate 21, the slit plate 20, and the side plate 22 In the assembled state, the second manifold 16 a above each slit 16 opens directly to the first manifold 14, and the second manifold 17 a above each slit 17 opens directly to the first manifold 15. . Further, the openings on the side surfaces other than the slits 16 and the portions of the second manifold 16a that open to the first manifold 14 are closed by the wall surfaces of the side plates 21 and 22, and the first manifold 15 of each slit 17 and the second manifold 17a. Openings on the side surfaces other than the portion that is open are closed by the wall surfaces of the side plates 21 and 22. The second manifolds 16a and 17a of the slits 16 and 17 directly open to the first manifolds 14 and 15, each slit 16 communicates with the first manifold 14 through the second manifold 16a, and each slit 17 is The first manifold 15 communicates with the second manifold 17a.

  In the present embodiment, the second manifold is inclined. However, the second manifold is not necessarily inclined, and a plurality of first manifolds and second manifolds communicate with each other between the slit plate and the side plate corresponding to every other second manifold. It is also possible to adopt a configuration in which plates with holes are arranged on both sides of the slit plate.

  The plurality of molten material introduction paths 12 are coupled to the molten material introduction tube 1 shown in FIG. 1 and receive the supply of the molten material A from the molten material introduction tube 1. The molten material A supplied from each molten material introduction path 12 into the first manifold 14 is formed in the first manifold 14 in the stacking direction of the first manifold 14 (a sector shape in which slits are formed in the XZ plane of FIG. 2). In the circumferential direction) and fills the first manifold 14. The molten material A in the first manifold 14 flows into the respective second manifolds 16a from the entrances of the respective second manifolds 16a that are open to the first manifold 14, and the width direction of the second manifolds 16a (in FIG. 3). After flowing in the Y direction perpendicular to the paper surface and filling the second manifold 16a, it flows down through the communicating slits 16 and flows out from the outlets of the slits 16 to the junctions 18.

  The plurality of molten material introduction paths 13 are coupled to the molten material introduction pipe 2 shown in FIG. 1 and receive supply of the molten material B from the molten material introduction pipe 2. The molten material B supplied from each molten material introduction path 13 into the first manifold 15 is formed in the first manifold 15 in the stacking direction of the first manifold 15 (a sector shape in which slits are formed in the XZ plane of FIG. 2). In the circumferential direction) and fills the first manifold 15. The molten material B in the first manifold 15 flows into the respective second manifolds 17a from the entrances of the respective second manifolds 17a that are open to the first manifold 15, and the width direction of the second manifolds 17a (in FIG. 3). (Y direction perpendicular to the paper surface) and the second manifold 17a is filled, then flows down in the slits 17 communicating with each other, and flows out from the outlets of the slits 17 to the junction 18.

  The sheet-like flows of the molten material A and the sheet-like flows of the molten material B that have flowed out to the merging portion 18 are alternately laminated at the merging portion 18 to form a laminated flow. This laminated flow flows down the discharge path 19. The laminating direction of the molten material A and the molten material B in the laminated flow flowing down the discharge passage 19 coincides with the thickness direction of the produced laminated sheet.

  The laminated flow flowing down the discharge path 19 is introduced into the base 5 via the conduit 4 shown in FIG. The laminated flow is widened in a predetermined direction (a direction orthogonal to the lamination direction of the molten material A and the molten material B) in the die 5 and discharged from the die 5 as a laminated sheet 6, and the discharged laminated sheet 6 is It is cooled and solidified on the surface of the casting drum 7, sent to the next process (for example, stretching process) as an unstretched film 8, and formed into a multilayer film (not shown).

  4 (a) and 5 (a) are views showing cross sections S1 and S2 in FIG. 3, and the slit 16 and the slit 17 located adjacent to each other in the stacking direction of the slit plate 20 through the partition wall 20a. 4 (b) and 5 (b), the perspective view of the slit 16 and the slit 17 is shown enlarged.

  On the upper part of each slit 16 or 17, second manifolds 16a and 17a having a length T in the stacking direction (X-axis direction shown in FIGS. 4 and 5) are provided in the entire width in the slit width direction D. Further, enlarged portions 16b and 17b in which the slit gap S gradually increases toward the joining portion 18 are provided in the slit exit portion over the entire width in the slit width direction D.

  In this embodiment, as shown in FIGS. 4 (a) and 5 (a), the lower surfaces of the second manifolds 16a and 17a are replaced with the lower surfaces of the first manifolds 14 and 15 (see FIGS. 4 (a) and 5 (a)). Although it is adjusted to the lower side in the Z direction), it is not always necessary.

  Further, in this embodiment, as shown in FIGS. 4B and 5B, the second manifolds 16a and 17a are enlarged on both sides with respect to the slits 16 and 17, but one side is the slit 16 and the slit. It is good also as a structure which is comprised with 17 wall surfaces and expands only the other wall surface. Further, the shapes of the second manifolds 16a and 17a are substantially pentagonal shapes, but are not necessarily required to be in this shape. In the present embodiment, the cross-sectional area of the second manifold is the same in the slit width direction, but the cross-sectional area may be reduced as the distance from the first manifold increases.

  The molten material A flows from the first manifold 14 into the respective second manifolds 16a as indicated by arrows 14a in FIG. The inflowing molten resin A flows in the second manifold 16a in the slit width direction (Y-axis direction shown in FIG. 4) and fills the second manifold 16a, and then passes through the slit 16 in the slit passing direction (Z-axis direction shown in FIG. 4). By flowing down, the flow rate of the molten material in the slit width direction is made uniform.

  Similarly, the molten material B flows from the first manifold 15 into the second manifolds 17a as shown by the arrow 15a in FIG. The inflowing molten resin B flows in the second manifold 17a in the slit width direction (Y-axis direction shown in FIG. 5) and fills the second manifold 17a, and then passes through the slit 17 in the slit passing direction (Z-axis direction shown in FIG. 5). By flowing down, the flow rate of the molten material in the slit width direction is made uniform.

  The molten material flowing down the slits 16 and 17 is gradually enlarged in the stacking direction (X-axis direction in FIGS. 4 and 5) at the enlarged portions 16b and 17b of the slit outlet and merged with the molten material flowing down from the adjacent slits. Therefore, it is possible to prevent the molten material from being disturbed at the junction. As a result, a variation in the thickness of each layer in the slit width direction at the exit portion of each slit can be kept small, and a laminated sheet having a uniform and high-quality laminated structure with no interlayer disturbance can be obtained.

  That is, a laminated sheet having good lamination accuracy as shown in FIG. 11 and a laminated sheet having good uniformity in the width direction of the sheet can be obtained. The slit gap S between the slits 16 and 17 may be the same gap when the film to be manufactured is a film having the same layer thickness in the thickness direction. By changing S stepwise or continuously from one end to the other along the stacking direction (the sector-shaped circumferential direction in which the slit is formed in the XZ plane of FIG. 3), the pressure loss of each slit changes. This can be achieved by adjusting the flow rate of the molten material passing therethrough.

  Using the multilayer feed block 3 shown in FIG. 3, a biaxially stretched multilayer film was produced by the laminated sheet producing apparatus shown in FIG. 1, and the effect of this embodiment was confirmed. Specific examples of confirmation of this effect are shown in the following Examples 1 to 3 and Comparative Examples 1 and 2.

  In addition, the measuring method of each measured value is as follows.

(1) Lamination thickness, the number of laminations, and lamination structure The layer structure of the film was obtained by observing an electron microscope with respect to a sample obtained by cutting a cross section using a microtome. That is, using a transmission electron microscope H-7100FA type (Hitachi Ltd.), the cross section of the film was magnified 40000 times at an acceleration voltage of 75 kv, a cross-sectional photograph was taken, and the layer configuration and each layer thickness were measured. In some cases, in order to obtain a high contrast, a known dyeing technique using RuO4 or OsO4 may be used.

  A specific method for obtaining the lamination thickness will be described. An image of a cross-sectional photograph taken by the above method was captured at an image size of 720 dpi using a CanonScan D123U. The image is saved in the JPEG format, and then image processing software Image-Pro Plus ver. This JPEG file was opened using 4 (distributor Planetron Co., Ltd.) and image analysis was performed. In the image analysis process, the relationship between the thickness in the thickness direction and the average brightness of the area sandwiched between the two lines in the width direction was read as numerical data in the vertical thick profile mode. Using the spreadsheet software (Excel2000), the position (nm) and brightness data were subjected to numerical processing of sampling step 6 (decimation 6) and 3-point moving average. Furthermore, the data obtained by periodically changing the brightness is differentiated, and the maximum value and the minimum value of the differential curve are read by the VBA program. Calculated. This operation was performed for each photograph, and the layer thicknesses of all layers were calculated.

(2) Melt viscosity The dynamic viscoelastic layer measurement was performed using a rotational rheometer MR-300 solid meter (manufactured by Rheology). For the measurement, a parallel disk (diameter 18 mm) was used, and the complex viscosity at 280 ° C., amplitude 1 °, and shear rate 15 s ⁻¹ in a nitrogen atmosphere was defined as shear viscosity. In addition, about the material used for film forming after drying in the Example, it dried on the same conditions also in this measurement.

(3) Definition of Lamination Thickness Unevenness Nine locations were sampled at equal intervals from the center in the film width direction, and the thickness of each layer in the film width direction position was calculated by the method described in (1). For each layer stacked, the maximum thickness was dmax, the minimum thickness was dmin, the average thickness was dav, and the thickness unevenness was (dmax−dmin) / dav. The largest value among the thickness unevenness of the obtained layers is defined as the film thickness unevenness. Table 1 shows that the film thickness unevenness of the film is less than 0.02, ◯, 0.02 or more and less than 0.05, ◯, 0.05 or more and less than 0.1, and 0.1 or more. Was marked with x.
[Example 1]
Two types of molten material A and molten material B were prepared. As the molten material A, polyethylene terephthalate (PET) (F20S, manufactured by Toray Industries, Inc.) having a melt viscosity at 280 ° C. of 180 Pa · s was used. As the molten material B, polyethylene terephthalate (PE / CHDM · T) (PETG6763 manufactured by Eastman Co., Ltd.) obtained by copolymerizing 30 mol% of cyclohexanedimethanol having a melt viscosity at 280 ° C. of 350 Pa · s with respect to ethylene glycol was used. These molten materials A and B were dried and then fed to an extruder.

  The melted materials A and B are each melted at a temperature of 280 ° C. by an extruder, measured with a gear pump so that the discharge ratio of melted material A / melted material B is 1/1, and after passing through a filter, It introduced into the multilayer feed block from the introduction pipe. As the multilayer feed block, the size (unit: mm) of the main part of the first manifold 14 (15) and the slit 16 (17), the dimension in the stacking direction of the second manifold, and the second manifold are shown in FIG. As shown in FIG. 6B, the downstream slit gap is 3 mm in the stacking direction of the second manifold, 5 mm in length, 0.8 mm in the slit gap downstream of the second manifold, and the length of the enlarged portion at the slit outlet. The number of slits into which the molten material A is introduced is 101 and the number of slits into which the molten material B is introduced is set to be 1.5 mm and the gap is 2 mm at the slit exit, and the total number of laminations 201 is 100. The apparatus which becomes is used.

  After the lamination is completed with the multilayer feed block, the laminated flow of the obtained molten material is supplied to the T die 5 shown in FIG. 1, formed into a sheet shape, and then subjected to electrostatic application (DC voltage 8 kV). The film was rapidly cooled and solidified on a casting drum 7 at a temperature of 25 ° C. to obtain an unstretched film.

  The obtained unstretched film is sequentially guided to a biaxial stretching machine, stretched at a temperature of 100 ° C in the longitudinal direction (film longitudinal direction) by 3.5 times, and then guided to a tenter and transversely at 105 ° C (film width direction). The film was stretched by 3.5 times. Furthermore, heat treatment is performed with hot air at a temperature of 230 ° C., and at the same time, 5% relaxation treatment is performed in the vertical direction, followed by 5% relaxation treatment in the horizontal direction. And wound up. The obtained film has a width of 600 mm and a thickness of 18 μm, and 201 layers of PET and PE / CHDM · T are alternately laminated, and the lamination thickness unevenness in the width direction of the film is very good, and the interlaminar disturbance It was satisfactory without uneven reflection. The results are shown in Table 1.

[Example 2]
A multilayer film was produced in the same manner as in Example 1 except that the dimensions shown in FIGS. 6A and 6B were changed as shown in Table 1. Table 1 shows a summary of the dimensions of the slit portions and the results of uneven stacking thickness.
[Example 3]
A multilayer film was produced in the same manner as in Example 1 except that the dimensions shown in FIGS. 6A and 6B were changed as shown in Table 1. Table 1 shows a summary of the dimensions of the slit portions and the results of uneven stacking thickness.
[Comparative Example 1]
As the multilayer feed block, a laminating apparatus constituted by a conventional slit without a second manifold was used. As shown in FIGS. 7A and 7B, the main dimensions of the slits are 101 in which the number of slits into which the molten material A is introduced is the same as in Example 1 except that the second manifold is not provided. A multilayer film was produced in the same manner as in Example 1 using an apparatus in which the number of slits into which B was introduced was 100 and the total number of layers was 201. Lamination thickness unevenness in the film width direction was sufficient as a film used for decorative purposes, but there was a problem as a film used for industrial materials having high required performance. Table 1 shows a summary of the dimensions of the slit portions and the results of uneven stacking thickness.
[Comparative Example 2]
As the multilayer feed block, the laminating apparatus shown in FIGS. 9 and 10 proposed by the present inventor was used. As shown in FIG. 8A and FIG. 8B, the main dimensions of the slit are as follows: the slit gap in the narrow portion is 0.3 mm, the slit length in the narrow portion is 5 mm, and the number of slits into which the molten material A is introduced A multilayer film was produced in the same manner as in Example 1 using an apparatus having a total number of laminations 201 of 101 and a number of slits 100 into which the molten material B was introduced. Lamination thickness unevenness in the film width direction was greatly improved as compared with Comparative Example 1, but it was still not sufficient. Table 1 summarizes the dimensions of the slits and the results of uneven stacking thickness.

  As can be seen from Table 1, according to the present embodiment, a uniform laminated film can be obtained by improving the uniformity of the laminated thickness in the width direction of the laminated film.

  In the above embodiment, the case where a laminated sheet or a multilayer film of two types of molten materials is manufactured has been described. However, in the case of having three or more manifolds and corresponding slit rows, at least one of them. By applying this embodiment to two types of molten materials (that is, at least two manifolds and two slit rows corresponding to them), the same effect as in the above-described example can be obtained.

  In the laminated sheet produced by the present invention, a plurality of types of molten materials (for example, a molten resin or a molten polymer) are laminated in a plurality of layers larger than the number of the types, and then the molten material is solidified. It is formed. The laminated sheet produced according to the present invention is used for every application, but is particularly suitable for applications requiring high lamination accuracy. Certain types of laminated sheets produced according to the present invention have optical characteristics due to the fact that the layer thickness of each layer is changed with high accuracy, and have a broadband interference reflection film, a refractive index control film, and a layer thickness. It is preferably used as a nano-order laminated film.

1: Molten material introduction tube to which molten material A is supplied 2: Molten material introduction tube to which molten material B is supplied 3: Multi-layer feed block 4: Conduit through which a laminated flow flows 5: Die (T-die)
6: Laminated sheet 7: Casting drum 8: Unstretched film 12, 13: Molten material resin introduction path 14: First manifold on the molten material A side 15: First manifold on the molten material B side 16, 17: Slits 16a, 17a : Second manifold 18: Junction part 19: Discharge path 20: Slit plate 20 a: Partition wall 21 and 22: Side plate 101: Multi-layer feed block 102 and 103: Resin introduction side 104: Resin A side manifold 105: Resin B side manifold 106, 107: slit 108: partition 109: narrow portion X: stacking direction Y: slit width direction Z: slit passing direction

Claims (9)

A laminated sheet manufacturing apparatus for laminating a plurality of types of molten materials so as to form a layer having a larger number of layers than the number of the types,
A plurality of first manifolds for supplying each of the molten materials;
A plurality of slits communicating with any one of the first manifolds and allowing the molten material supplied in the first manifolds to pass from the first manifolds in the slit passing direction corresponding to the layers;
A joining portion that joins each molten material that has passed through the plurality of slits while overlapping each other in the stacking direction perpendicular to the slit passing direction,
Each of the slits communicating with any one of the plurality of first manifolds has a dimension in the stacking direction larger than the slit gap of each slit at a portion communicating with the first manifold of each slit, and is separated from the first manifold. And a second manifold whose upper end and lower end both incline in the downstream direction is provided in all of the slit width direction. 2. The laminated sheet manufacturing apparatus according to claim 1, wherein S is a slit gap of the plurality of slits, and T is a maximum dimension in the stacking direction of the second manifold.
2.5S ≤ T ≤ 5S   3. The laminated sheet manufacturing apparatus according to claim 1, wherein a cross-sectional area of the second manifold decreases as the distance from the first manifold increases.   The said each slit is laminated | stacked radially and arrange | positioned, The manufacturing apparatus of the lamination sheet in any one of Claims 1-3 characterized by the above-mentioned.   The apparatus for producing a laminated sheet according to any one of claims 1 to 4, wherein a slit gap of each of the slits gradually increases in the vicinity of the joining portion toward the joining portion.   The slit gap of each of the slits changes stepwise or continuously from one end to the other end of the slit excluding the slit at the outermost end in the stacking direction. The manufacturing apparatus of the laminated sheet of description.   The slit width of each said slit is 20 mm or more and 100 mm or less, The manufacturing apparatus of the lamination sheet in any one of Claims 1-6 characterized by the above-mentioned.   8. The laminated sheet manufacturing apparatus according to claim 1, wherein a plurality of material introduction ports for supplying each molten material to each first manifold are provided. A method for producing a laminated sheet in which a plurality of types of molten materials are laminated so as to form a layer having a larger number of layers than the number of the types,
The molten materials are supplied to a plurality of slits that communicate with any one of the first manifolds and pass in the slit passing direction corresponding to the respective layers via the plurality of first manifolds. When the molten materials supplied to the two are joined together in the stacking direction perpendicular to the slit passing direction, the first manifold of each slit is used as each slit communicating with one of the plurality of first manifolds. The second manifold has a larger dimension in the stacking direction than the slit gap of each of the slits in the portion communicating with the first manifold, and the upper end and the lower end of the second manifold both incline in the downstream direction as they move away from the first manifold. A method for producing a laminated sheet, wherein a slit provided is used.

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