JP2008030258A - Method and apparatus for manufacturing laminated sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated sheet manufacturing apparatus capable of easily manufacturing a multilayered film of high quality by suppressing the occurrence of an interfacially unstable phenomenon without requiring a complicated control unit by restricting the dimension of the flow channel for connecting a laminator and a cap and that of the discharge port of the cap corresponding to the layer thickness of a laminate, and a laminated sheet manufacturing method. <P>SOLUTION: This laminated sheet manufacturing apparatus is equipped with the laminator for forming the laminate, wherein a plurality of kinds of sheet materials a laminated to layers the number of which is larger than the number of the kinds, and the cap provided on the downstream side of the laminator to mold the laminate into a sheetlike form. When the dimension in the lateral direction of the sheet of the arbitrary cross section vertical to a flow channel direction in the flow channel which connects the laminator and the cap is set to W, the dimension in the thickness direction of the sheet is set to T, the dimension in the width direction of the sheet of the discharge port of the cap is set to Wd and the minimum dimension in the thickness direction of the sheet of the uppermost surface layer of the laminate is set to L, the relation of the formula (1):1<Wd/W<10 and the formula (2): W/T≤5÷(T/L)+5 is satisfied. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  Today, the use of a multilayer film having a multilayer structure in which a plurality of types of sheet materials are laminated in the thickness direction of the film is spreading to optical applications. Among them, in order to satisfy more excellent optical properties, a high-quality super multi-layer film is required even though the number of laminated layers is as large as 100 to 1000 or more. However, in the case of forming a super multi-layer film, there is a problem that the probability of occurrence of an interface instability phenomenon such as a flow mark or layer tearing is significantly increased as compared with a conventional multi-layer film. According to the knowledge of the present inventors, it is considered that a shear stress applied to the interface can be cited as a major cause of this instability phenomenon. In the super multi-layer film, the number of laminated layers is enormous such as 100 to 1000 layers or more, so the thickness of each layer is very small. That is, when an ultra-multilayer film is formed, an interface exists in a region having a large shear stress near the wall surface, and a strong shear stress is applied to the interface. Therefore, it can be said that the instability phenomenon frequently occurs when the super multi-layer film is formed.

  As a manufacturing apparatus and a manufacturing method of a laminated sheet for forming a multilayer film, a plurality of types (especially two types) of sheet materials (typically, molten resin, etc.) are divided by a laminating apparatus through a plurality of slits. There is known a method of forming a laminated sheet having a plurality of layers and discharging the laminated body from a die having a slit gap extending in the sheet width direction to form a laminated sheet. And the lamination sheet discharged from the nozzle | cap | die is used as a multilayer film as it is or after post-processing, such as extending | stretching.

  By the way, there exists a manufacturing apparatus of the lamination sheet currently disclosed by patent document 1 and patent document 2 as a technique which looks similar to the preferable form of this invention at first glance.

  In Patent Document 1, a sheet width direction dimension of an arbitrary cross section perpendicular to a flow path direction in a flow path connecting a laminating apparatus for manufacturing a multilayer film having a number of layers of about 3 layers and a die is W, a sheet thickness A sheet material layer on the low-viscosity side is defined by defining the directional dimension as T, the sheet width direction dimension of the discharge port of the die as Wd, and limiting to a range of 20 <W / T <30 and 5 ≦ Wd / W ≦ 17. Discloses a method of suppressing a so-called “wrapping phenomenon” that wraps a layer of a sheet material on the high viscosity side and reducing thickness unevenness in the sheet width direction of each layer. Certainly, the so-called “wrapping phenomenon” causes uneven thickness in the sheet width direction of each layer, but as the number of layers increases, the effect cancels and decreases, so the technique disclosed in Patent Document 1 is applied to the super multilayer film. Even if it is applied to the formation of the film, the effect is reduced.

  Patent Document 2 discloses a sheet width direction dimension of an arbitrary cross section perpendicular to a flow path direction in a flow path connecting a laminating apparatus for manufacturing a multilayer film having a number of layers of about 3 and a die in solution casting. Is W, T is the sheet thickness direction dimension, Wd is the sheet width direction dimension of the outlet of the die, and is limited to the range of 2 <W / T <10 and 10 ≦ Wd / W ≦ 25. A method has been disclosed in which unevenness in thickness in the sheet width direction of each layer can be reduced even if the residence time from the apparatus to the discharge port of the base is shortened to increase the discharge amount and increase the production amount. Certainly, in the case of solution casting, the influence of the residence time of the solution on the thickness unevenness in the sheet width direction of each layer is large, but in the case of melt casting, the influence of the residence time on the thickness unevenness of each layer in the sheet width direction is Even if the technique disclosed in Patent Document 2 is applied to the formation of a super multi-layer film, the effect is reduced.

In addition, according to the knowledge of the present inventors, in the conventional laminated sheet manufacturing apparatus such as Patent Document 1 and Patent Document 2, although the unevenness in thickness in the sheet width direction of each layer can be improved, It was difficult to improve.
Japanese Patent No. 3516099 Japanese Patent No. 3727883

  An object of the present invention is to provide a laminated sheet manufacturing apparatus and a manufacturing method capable of easily producing a high-quality multilayer film by suppressing the occurrence of an interface instability phenomenon without requiring a complicated control device. There is.

  In order to achieve the above object, the present invention provides a laminating apparatus for forming a laminate in which a plurality of types of sheet materials are laminated in a number greater than the number of the types, and provided on the downstream side of the laminating apparatus. An apparatus for manufacturing a laminated sheet comprising a die for forming a laminated body into a sheet shape, wherein a sheet width direction dimension of an arbitrary cross section perpendicular to a flow path direction in a flow path connecting the lamination device and the die is provided. When W, the sheet thickness direction dimension is T, the sheet width direction dimension of the discharge port of the base is Wd, and the minimum sheet thickness direction dimension of the outermost surface layer of the laminate is L, the relationship between Expression (1) and Expression (2) An apparatus for producing a laminated sheet satisfying both of the above is provided.

  Moreover, according to the preferable form of this invention, the manufacturing apparatus of the lamination sheet which satisfies 10 <= T / L <= 1000 is provided further.

  Moreover, according to the preferable form of this invention, the manufacturing apparatus of the lamination sheet whose said sheet width direction dimension W is further 50mm <W <300mm is provided.

  Moreover, according to the preferable form of this invention, the manufacturing apparatus of the lamination sheet whose said sheet thickness direction dimension T is T <1000mm is provided further.

  Further, according to another aspect of the present invention, a lamination body is formed by laminating a plurality of types of sheet materials on a number of layers larger than the number of the types by a laminating device, and a die provided downstream of the laminating device A method for producing a laminated sheet, in which the laminate is formed into a sheet shape, wherein W is a sheet width direction dimension of an arbitrary cross section perpendicular to a flow path direction in a flow path connecting the laminating apparatus and the die. When the dimension in the thickness direction is T, the dimension in the sheet width direction of the discharge port of the die is Wd, and the dimension in the minimum sheet thickness direction of the outermost layer of the laminate is L, both the relations of the expressions (1) and (2) are satisfied. There is provided a method for producing a laminated sheet, wherein the flow path is used.

  In the present invention, “sheet material” refers to, for example, polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resins, polyethylene terephthalate, poly Polyethylene resins such as butylene terephthalate, polypropylene terephthalate, polybutyl succinate, polyethylene-2,6-naphthalate, polycarbonate resin, polyarylate resin, polyacetal resin, polyphenylene sulfide resin, tetrafluoroethylene resin, trifluoroethylene resin, 3 Fluorocarbon resins such as fluorinated ethylene resin, ethylene tetrafluoride-6-propylene copolymer, vinylidene fluoride resin, acrylic resin, methacrylic resin, It can be used re acetal resin, polyglycolic acid resin, polylactic acid resin, a material obtained by fluidized, for example, by melting 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.

  Further, in the present invention, the “laminate” is a sheet material having a multilayer structure in which a plurality of types of sheet materials are laminated as a plurality of layers between the time when the laminate is extruded from the extruder and the time when the laminate is discharged from the die. Say.

  Further, in the present invention, “laminated sheet” refers to a laminated body whose width and thickness are adjusted and discharged from a die.

  Further, in the present invention, the “multilayer film” refers to a laminated sheet solidified and subjected to post-treatment such as stretching as it is.

  In the present invention, the “lamination device” refers to a device for forming a laminate.

  In the present invention, the “flow path connecting the laminating apparatus and the base” means a flow path in the sheet width direction by the manifold inside the base from the 1 mm downstream portion of the position where the lamination of the sheet material is completed inside the laminating apparatus. The flow path through which the laminated body flows up to 1 mm upstream of the position where the widening of the film starts.

  Further, in the present invention, the “flow channel direction” refers to the direction in which the laminate flows in each part of the flow channel connecting the laminating apparatus and the base.

  In the present invention, the “sheet thickness direction” refers to the direction in which the layers of the laminated sheet are laminated.

  In the present invention, the “sheet width direction” refers to a direction orthogonal to both the flow path direction and the sheet thickness direction of the laminated sheet.

  In the present invention, “the minimum sheet thickness direction dimension L of the outermost layer of the laminate” refers to a dimension at a portion where the thickness of the outermost layer of the laminate is the thinnest. The minimum sheet thickness direction dimension L of the outermost layer of the laminate can be calculated using the following method. First, the thickness of each layer in a multilayer film is measured. Next, since the ratio of the thickness of each layer in the multilayer film matches the ratio of the flow rate of each layer in the laminate, the flow rate of each layer in the laminate is calculated. And if the flow velocity distribution of the laminated body in the flow path connecting the laminating apparatus and the base is approximated as a quadratic function of the sheet thickness direction dimension, the thickness of each layer in the laminated body can be calculated from the flow rate. Therefore, in the multilayer film, when the ratio of the minimum thickness of the outermost layer to the thickness of the entire film is Ls, the minimum sheet thickness direction dimension L of the outermost layer of the laminate in the flow path connecting the laminating apparatus and the die is represented by the formula ( It can be calculated from 3). In this case, the minimum sheet thickness direction dimension L of the outermost layer of the laminate can be calculated by deriving a cubic equation of the dimension L by numerical analysis or the like.

  The production apparatus and production method for a laminated sheet according to the present invention do not require a complicated control device, can suppress the occurrence of an interface instability phenomenon, and can produce a high-quality multilayer film.

  Hereinafter, the present embodiment will be described in detail. However, the present invention is not limited to the embodiment including the following examples, and the object of the invention can be achieved and within the scope not departing from the gist of the invention. Various changes are naturally possible.

  1 to 8 are diagrams relating to the laminated sheet manufacturing apparatus of the present embodiment. 1 to 8, members having the same use and function may have the same reference numerals.

  In this embodiment, a laminate having a plurality of layers is formed by diverting a plurality of types (especially two types) of sheet materials (typically, molten resin, etc.) through a plurality of slits by a laminating apparatus. Is discharged from a die having a slit gap extending in the sheet width direction to form a laminated sheet.

  A basic configuration of the laminated sheet manufacturing apparatus of the present embodiment is shown in FIG. In FIG. 1, the laminated sheet manufacturing apparatus is supplied by sheet material introduction pipes 1 and 2 and sheet material introduction pipes 1 and 2 for supplying sheet material A and sheet material B extruded from separate extruders (not shown). The sheet material A and the sheet material B are laminated in a laminating apparatus 3 for forming a laminated body alternately, the conduit 4 for guiding the laminated body from the laminating apparatus 3 to the downstream side, and the width and thickness of the laminated body from the conduit 4 are set to a predetermined value. It has a base 5 that adjusts and discharges the value to form a laminated sheet. Reference numeral 7 denotes a casting drum that cools and solidifies the laminated sheet 6 discharged from the base 5. 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.

  Moreover, when forming the laminated body which has a lamination | stacking number of 20 layers or more, the lamination apparatus 3 used in the manufacturing apparatus of the lamination sheet of this embodiment is comprised so that a flow path as shown in FIG. 2 may be formed. There are many cases. FIG. 2 is a schematic perspective view showing the internal space of the laminating apparatus 3, and shows the space portion formed in the laminating apparatus 3, that is, the flow path of the sheet material. The laminating apparatus 3 includes sheet material introduction paths 11 and 12 for supplying the sheet material A and the sheet material B therein, and the sheet material A and the sheet material B supplied by the sheet material introduction paths 11 and 12 in the sheet thickness direction. Manifolds 13 and 14 that expand to a small size, a row of a large number of pores 15 and 16 that divide the sheet material A and sheet material B from the manifolds 13 and 14 into a predetermined number of layers, and a sheet from each of the pores 15 and 16 A plurality of stacking apparatus slits 17 and 18 for guiding the material A and the sheet material B downstream, and a stacking completion section 19 is provided on the exit side of the slits 17 and 18 of each stacking apparatus. In addition, a large number of sheet materials A and sheet materials B from the slits 17 and 18 of each laminating apparatus can be alternately laminated to form a laminated body.

  Moreover, when forming the laminated body which has a lamination | stacking number of less than 20 layers, the lamination apparatus 3 used in the manufacturing apparatus of the lamination sheet of this embodiment is comprised so that a flow path as shown in FIG. 3 may be formed. There are many. FIG. 3 is a schematic perspective view showing the internal space of the laminating apparatus 3, and represents a space portion formed in the laminating apparatus 3, that is, a flow path of the sheet material. The laminating apparatus 3 includes sheet material introduction paths 11 and 12 for supplying the sheet material A and the sheet material B therein, and the sheet material A and the sheet material B supplied by the sheet material introduction paths 11 and 12 in the sheet thickness direction. Manifolds 13 and 14 that expand to a small size, a row of a large number of pores 15 and 16 that divide the sheet material A and sheet material B from the manifolds 13 and 14 into a predetermined number of layers, and a sheet from each of the pores 15 and 16 Expands material A and sheet material B in the sheet width direction, and has a large number of rows of manifold-equipped slits 17m and 18m leading to the downstream side. A plurality of sheet materials A and sheet materials B from the manifold-equipped slits 17m and 18m are alternately laminated to form a laminate. So that the can be formed. And the flow path in the lamination apparatus 3 is made into the structure which this applicant proposed in Japanese Patent Application No. 2005-286331, and the sheet | seat width direction thickness nonuniformity of each layer can be suppressed.

  Moreover, the conduit | pipe 4 and the nozzle | cap | die 5 which are used in the manufacturing apparatus of the lamination sheet of this embodiment are comprised so that a flow path as shown in FIG. 4 may be formed. FIG. 4 is a schematic perspective view showing the internal space of the lamination completion part 19, the conduit 4 and the base 5, and represents the space formed in the lamination completion part 19, the conduit 4 and the base 5, that is, the flow path of the sheet material. ing. The stacking completion part 19 and the conduit 4 have a flow path 24 that guides the stack formed by the stacking device 3 to the base 5 inside thereof. The base 5 includes a manifold 21 that extends the laminated body guided by the flow path 24 in the sheet width direction, a base slit 22 that reduces the laminated body from the manifold 21 in the sheet thickness direction, and a base slit. A discharge port 23 for discharging the laminate from 22 as a laminate sheet is provided, and a laminate whose width and thickness are adjusted to predetermined values can be discharged to form a laminate sheet. Here, the sheet width direction dimension of the arbitrary cross section perpendicular to the flow path direction in the flow path 24 connecting the laminating apparatus 3 and the base 5 is W, the sheet thickness direction dimension is T, and the sheet width of the discharge port 23 of the base 5 is. The direction dimension is Wd. Further, the flow path 24 connecting the laminating apparatus 3 and the base 5 is an outlet located on the most downstream side of the outlets of the slits 17 and 18 of each laminating apparatus inside the laminating apparatus 3 or the slits 17m and 18m with manifolds. A flow path through which the laminated body flows from 1 mm downstream to 1 mm upstream of the position where the manifold 21 starts to widen the flow path in the sheet width direction inside the base 5.

  FIG. 5 is a cross-sectional view of an arbitrary cross section perpendicular to the flow path direction in the flow path 24 through which the laminate is passing. The laminate 31 includes a layer 32 of sheet material A and a layer 33 of sheet material B. Here, from the relationship of the flow velocity distribution, the stronger shear stress is applied to the interface of the laminate 31 as it is closer to the wall surface perpendicular to the sheet thickness direction of the flow path 24. The interface is the interface 34. The distance between the sheet thickness direction of the flow path 24 and the wall surface perpendicular to the flow path 24 of the interface 34 to which the strongest shear stress is applied, that is, the minimum sheet thickness direction dimension of the outermost layer of the laminate 31 is L.

  As a result of intensive studies, the present inventors have found that in any cross section perpendicular to the flow path direction of the flow path 24, that is, in each cross section from the most upstream to the most downstream of the flow path 24, the expressions (1) and (2 It was found that a laminated sheet free from interface instability phenomenon can be obtained by satisfying both of the above relationships.

  By setting it as such a structure, the shear stress concerning the interface of a laminated body can be reduced and an interface instability phenomenon can be suppressed. Here, the die widening ratio Wd / W is the sheet width direction widening ratio of the laminate by the die, and the cross-sectional dimension ratio W / T is a parameter that determines the flow velocity distribution of the flow path through the laminate, and the layer thickness ratio T / L Means a parameter representing the degree to which the interface of the laminate that receives the most shear stress is subjected to the shear stress.

  When the value of the base widening ratio Wd / W is 10 or more, the shear stress in the sheet width direction generated when the laminate is widened in the sheet width direction becomes large, and an interface instability phenomenon occurs. Further, when the value of the base widening ratio Wd / W is 1 or less, the size of the apparatus is increased. In order to make the apparatus more compact, it is preferable that 5 <Wd / W <10.

  The inventors have found that the value of the cross-sectional dimension ratio W / T is preferably in the range shown in FIG. FIG. 9 is a graph showing the range of the cross-sectional dimension ratio W / T where the interface instability phenomenon does not occur with respect to the layer thickness ratio T / L. The horizontal axis represents the layer thickness ratio T / L, and the vertical axis represents the cross-sectional dimension ratio W. / T. The dotted line represents the formula (4), and the colored part represents the range of the formula (2). As the value of the cross-sectional dimension ratio W / T increases, the flow velocity gradient near the wall surface increases and the shear stress applied to the interface increases. Further, when the value of the layer thickness ratio T / L increases, the interface to which the largest shear stress is applied is similar to the wall surface, so that the shear stress applied to the interface increases. In other words, this graph shows that the shear stress applied to the interface depends on the relationship between the value of the cross-sectional dimension ratio W / T and the value of the layer thickness ratio T / L. As the value of T / L increases, the shear stress applied to the interface increases, meaning that an interface instability phenomenon may occur. Considering that the sheet thickness direction dimension L is instantaneously decreased due to an extrusion failure of the extruder or a temperature unevenness of the heater, and the value of the layer thickness ratio T / L increases rapidly, W / T ≦ 5 It is preferable that

  Examples of the conduit 4 and the base 5 that can be configured to fall within such a range are shown in FIGS.

  FIG. 6 shows an example of the lamination completion unit 19, the conduit 4, and the base 5 used in the laminated sheet manufacturing apparatus of this embodiment. When the sheet width direction dimension from the laminating device 3 of the flow path 24 is W1, the sheet thickness direction dimension is T1, the sheet width direction dimension from the base 5 is W2, and the sheet thickness direction dimension is T2, the sheet width direction dimensions W1 and W2 The sheet thickness direction dimensions T1 and T2 are both equal, and each dimension of the flow path 24 does not change with respect to the flow path direction.

  FIG. 7 shows an example of the lamination completion unit 19, the conduit 4, and the base 5 used in the laminated sheet manufacturing apparatus of the present embodiment different from FIG. 6. When the sheet width direction dimension from the laminating device 3 of the flow path 24 is W1, the sheet thickness direction dimension is T1, the sheet width direction dimension from the base 5 is W2, and the sheet thickness direction dimension is T2, the sheet width direction dimensions W1 and W2 However, the sheet thickness direction dimension T2 is smaller than T1, and only the sheet thickness direction dimension of the flow path 24 is continuously reduced with respect to the flow path direction.

  FIG. 8 shows an example of the lamination completion unit 19, the conduit 4, and the base 5 used in the laminated sheet manufacturing apparatus of the present embodiment different from those in FIGS. 6 and 7. When the sheet width direction dimension from the laminating apparatus 3 of the flow path 24 is W1, the sheet thickness direction dimension is T1, the sheet width direction dimension from the base 5 is W2, and the sheet thickness direction dimension is T2, the sheet thickness direction dimensions T1 and T2 However, the sheet width direction dimension W2 is larger than W1, and only the sheet width direction dimension of the flow path 24 is configured to increase stepwise with respect to the flow path direction.

  In addition, when the number of layers is very large as in the case of an ultra-multilayer film, the uneven thickness in the sheet width direction of each layer is not due to the so-called “wrapping phenomenon”, but mainly due to a sudden change in the flow of the laminate due to the widening of the die. is there. In order to suppress this rapid change in the flow of the laminated body, the width of the laminated body in the sheet width direction by the die and the flow velocity of the laminated body are reduced, that is, the values of the die widening ratio Wd / W and the cross-sectional dimension ratio W / T. Need to be small. Therefore, reducing the values of the base widening ratio Wd / W and the cross-sectional dimension ratio W / T used in the laminated sheet manufacturing apparatus of the present embodiment as much as possible suppress the thickness unevenness in the sheet width direction of each layer. effective.

  Further, by setting the value of the layer thickness ratio T / L used in the laminated sheet manufacturing apparatus of the present embodiment in the range of 10 ≦ T / L ≦ 1000, the effect of suppressing the interface instability phenomenon can be increased. it can.

  Further, by making the value of the sheet width direction dimension W used in the laminated sheet manufacturing apparatus of this embodiment within the range of 50 mm <W <300 mm, the apparatus is not enlarged, and the interface instability phenomenon The effect which suppresses can be increased. That is, in order to obtain a pressure loss suitable for laminating sheet materials, it is necessary to increase the sheet width direction dimension W according to the total mass flow rate of the laminate, but the total mass flow rate of the laminate generally used is In a laminated sheet manufacturing apparatus of less than 4 ton / hour, when the sheet width direction dimension W is 300 mm or more, the flow path is simply increased and the apparatus is enlarged, and the sheet width direction dimension W is 50 mm or less. In this case, it is necessary to increase the base widening ratio, and the effect of suppressing the interface instability phenomenon is reduced.

  Moreover, the enlargement of an apparatus can be prevented by making the value of the sheet thickness direction dimension T used in the laminated sheet manufacturing apparatus of this embodiment into the range of T <1000 mm. That is, in order to obtain a pressure loss suitable for laminating sheet materials, it is necessary to increase the sheet thickness direction dimension T according to the total mass flow rate of the laminate, but the total mass flow rate of the laminate generally used is In the laminated sheet manufacturing apparatus of less than 4 ton / hour, when the sheet thickness direction dimension T is 1000 mm or more, the flow path is simply increased and the apparatus is simply enlarged.

[Example 1]
The result of actually manufacturing a multilayer film using the laminated sheet manufacturing apparatus of the present invention will be described. A specific method for producing a multilayer film in the present example is as follows.

(1) Sheet material: Sheet material A; polyethylene terephthalate (PET) resin (thermoplastic resin F20S manufactured by Toray Industries, Inc.), sheet material B: cyclohexanedimethanol copolymerized PET (thermoplastic resin PETG6763 manufactured by Eastman), sheet Material S: Cyclohexanedimethanol copolymerized PET (Etherman thermoplastic resin PETG6763)
(2) Preparation: Each sheet material is dried and then supplied to an extruder. The extruder was set to 280 ° C., and after passing through a gear pump and a filter, each sheet material was supplied to the laminating apparatus and joined.

  (3) Laminating apparatus: The laminating apparatus has a structure as shown in FIG. 3 and uses a slit with a manifold and two pores reduced from a slit with a manifold consisting of one A layer and two B layers. The resin was discharged, the target lamination ratio was A: B = 1: 1, and both surface layer portions were B layers. The sheet thickness direction dimension L is derived from the flow velocity distribution and is as shown in Table 1.

  (4) Discharge: Casting drum that is maintained at a surface temperature of 25 ° C. by applying electrostatic force (DC voltage: 8 kV) after supplying the laminated body through the conduit to the T-die and extruding it into a sheet after lamination is completed in the laminating apparatus. It was rapidly cooled and solidified and molded. The flow path connecting the laminating apparatus and the die and the discharge port of the die were formed as shown in FIG. Each dimension is as shown in Table 1.

  (5) Surface treatment: The formed cast film is conveyed by a roll, and in the coating apparatus, both surfaces of the cast film are subjected to corona discharge treatment in air, the wetting tension is 55 mN / m, and the glass transition temperature Tg18 is applied to the treated surface. A laminated film composed of a polyester resin at 0 ° C./a polyester resin having a Tg of 82 ° C./silica particles having an average particle diameter of 100 nm was applied to form a transparent, easy-to-slip and easy-adhesive layer.

  (6) Heat treatment: Subsequently, the film was sequentially guided to a biaxial stretching machine, preheated with hot air at 95 ° C., and then stretched 3.5 times in the longitudinal direction (film longitudinal direction) and lateral direction (film width direction). Further, heat treatment was performed with hot air at 230 ° C., and at the same time, 5% relaxation treatment was performed in the vertical direction, followed by 5% relaxation treatment in the horizontal direction.

  The interface instability in this example was evaluated by the following method.

  Interfacial instability phenomenon: Whether or not the interface instability phenomenon occurred was determined by visually observing the formed multilayer film. Also, in Table 1, the fact that the interface instability phenomenon does not occur means that the thickness or layer itself of the multilayer film is clearly disturbed due to the interface instability phenomenon, and wavy unevenness etc. can be visually confirmed, and is judged as a defective product. In the case where the ratio of the multilayer film is less than 5%, it is represented by ◯, and in other cases, it is represented by ×.

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 in FIG. 4 were changed as shown in Table 1 and the laminating apparatus was changed as shown below. The results are shown in Table 1.

Laminating apparatus: The laminating apparatus has the structure shown in FIG. 3 and has a manifold with slits and four pores, and the resin is supplied from the manifold with slits consisting of 5 layers of A and 4 layers of B. The target lamination ratio was A: B = 1: 1, and both surface layer portions were A layers. The sheet thickness direction dimension L is derived from the flow velocity distribution and is as shown in Table 1.
[Example 3]
A multilayer film was produced in the same manner as in Example 1 except that the dimensions in FIG. 4 were changed as shown in Table 1 and the laminating apparatus was changed as shown below. The results are shown in Table 1.

Laminating apparatus: A laminating apparatus having the structure shown in FIG. 2 is used, and the resin is ejected from a slit composed of 51 layers of A layer and 50 layers of B layer, and the target lamination ratio is A: B = 1: 1. Thus, both surface layer portions were made to be the A layer. The sheet thickness direction dimension L is derived from the flow velocity distribution and is as shown in Table 1.
[Example 4]
A multilayer film was produced in the same manner as in Example 1 except that the dimensions in FIG. 4 were changed as shown in Table 1 and the laminating apparatus was changed as shown below. The results are shown in Table 1.

Laminating apparatus: A laminating apparatus having the structure shown in FIG. 2 is used, and the resin is ejected from a slit formed of the A layer 401 layer and the B layer 400 layer, and the target lamination ratio is A: B = 1: 1. Thus, both surface layer portions were made to be the A layer. The sheet thickness direction dimension L is derived from the flow velocity distribution and is as shown in Table 1.
[Comparative Example 1]
A multilayer film was produced in the same manner as in Example 1 except that the dimensions in FIG. 4 were changed as shown in Table 1. The results are shown in Table 1. The die widening ratio Wd / W is within the range of the formula (1), but the cross-sectional dimension ratio W / T and the layer thickness ratio T / L are outside the range of the formula (2).
[Comparative Example 2]
A multilayer film was produced in the same manner as in Example 2 except that the dimensions in FIG. 4 were changed as shown in Table 1. The results are shown in Table 1. The die widening ratio Wd / W is within the range of the formula (1), but the cross-sectional dimension ratio W / T and the layer thickness ratio T / L are outside the range of the formula (2).
[Comparative Example 3]
A multilayer film was produced in the same manner as in Example 3 except that the dimensions in FIG. 4 were changed as shown in Table 1. The results are shown in Table 1. The die widening ratio Wd / W is within the range of the formula (1), but the cross-sectional dimension ratio W / T and the layer thickness ratio T / L are outside the range of the formula (2).
[Comparative Example 4]
A multilayer film was produced in the same manner as in Example 4 except that the dimensions in FIG. 4 were changed as shown in Table 1. The results are shown in Table 1. The die widening ratio Wd / W is within the range of the formula (1), but the cross-sectional dimension ratio W / T and the layer thickness ratio T / L are outside the range of the formula (2).
[Comparative Example 5]
A multilayer film was produced in the same manner as in Example 2 except that the dimensions in FIG. 4 were changed as shown in Table 1. The results are shown in Table 1. The cross-sectional dimension ratio W / T and the layer thickness ratio T / L are within the range of the formula (2), but the base widening ratio Wd / W is 10 or more.
[Comparative Example 6]
A multilayer film was produced in the same manner as in Example 3 except that the dimensions in FIG. 4 were changed as shown in Table 1. The results are shown in Table 1. The cross-sectional dimension ratio W / T and the layer thickness ratio T / L are within the range of the formula (2), but the base widening ratio Wd / W is 10 or more.

[Summary]
FIG. 10 shows the values of the cross-sectional dimension ratio W / T and the layer thickness ratio T / L in each Example and Comparative Examples 1 to 4 in the graph of FIG. Examples 1 to 4 are shown. As a result of these examples, from Table 1 and FIG. 10, when the dimension of the flow path connecting the examples, that is, the laminating apparatus and the die is a shape satisfying the relationship of the formula (2), it occurs in the multilayer film. Suppresses interfacial instability and forms a high-quality multilayer film.

  In Comparative Examples 5 and 6, from Table 1, the values of the cross-sectional dimension ratio W / T and the layer thickness ratio T / L are the same as those in Examples 2 and 3, and the shape satisfies the relationship of the expression (2). However, the value of the base widening ratio Wd / W does not satisfy the relationship of the formula (1), and as a result, the interface instability phenomenon occurring in the multilayer film cannot be suppressed. In other words, in order to suppress the interface instability phenomenon that occurs in the multilayer film, the dimensions of the flow path connecting the laminating apparatus and the die and the outlet of the die satisfy both the relations of the expressions (1) and (2). The shape needs to be.

  The laminated sheet produced according to the present invention is formed by laminating a plurality of types of sheet materials on a plurality of layers larger than the number of types, and solidifying the sheet material. According to the present invention, it is possible to easily produce a high-quality multilayer film by suppressing the occurrence of an interface instability phenomenon.

The perspective view for demonstrating the manufacturing apparatus and manufacturing process of the lamination sheet which are this embodiment. The fragmentary perspective view of internal space which shows the internal structure of the lamination apparatus used in the manufacturing apparatus of the lamination sheet which is this embodiment. The fragmentary perspective view of internal space which shows the internal structure of the lamination apparatus used in the manufacturing apparatus of the lamination sheet which is this embodiment. The fragmentary perspective view of internal space which shows the internal structure of the conduit | pipe and nozzle | cap | die used in the manufacturing apparatus of the lamination sheet which is this embodiment. Sectional drawing of the laminated body which flows through the inside of the flow path used in the manufacturing apparatus of the laminated sheet which is this embodiment. The fragmentary perspective view of internal space which shows the internal structure of the conduit | pipe and nozzle | cap | die used in the manufacturing apparatus of the lamination sheet which is this embodiment. The fragmentary perspective view of internal space which shows the internal structure of the conduit | pipe and nozzle | cap | die used in the manufacturing apparatus of the lamination sheet which is this embodiment. The fragmentary perspective view of internal space which shows the internal structure of the conduit | pipe and nozzle | cap | die used in the manufacturing apparatus of the lamination sheet which is this embodiment. The graph of cross-sectional dimension ratio W / T which does not generate | occur | produce the interface instability phenomenon with respect to layer thickness ratio T / L used in the manufacturing apparatus of the lamination sheet which is this embodiment. The graph of FIG. 9 which plotted the value of cross-sectional dimension ratio W / T and layer thickness ratio T / L of each Example.

Explanation of symbols

1: Sheet material introduction pipe to which sheet material A is supplied 2: Sheet material introduction pipe to which sheet material B is supplied 3: Laminating apparatus 4: Conduit 5: Base 6: Laminated sheet 7: Casting drum 8: Unstretched film 11 , 12: Sheet material introduction path 13, 14: Manifold 15, 16: Fine pores 17, 18: Slit of laminating apparatus 17m, 18m: Slit with manifold 19: Lamination completion part 21: Manifold 22: Slit of base 23: Discharge port 24: Channel 31: Laminate 32: Layer of sheet material A 33: Layer of sheet material B 34: Interface of laminate

Claims (5)

A laminating apparatus that forms a laminate in which a plurality of types of sheet materials are laminated in a number greater than the number of the types, and a die that is provided on the downstream side of the laminating apparatus and forms the laminate into a sheet shape. An apparatus for producing a laminated sheet, wherein a sheet width direction dimension of a cross section perpendicular to a flow path direction in a flow path connecting the lamination apparatus and the die is W, a sheet thickness direction dimension is T, A laminated sheet characterized by satisfying both the relations of the formulas (1) and (2), where Wd is a dimension in the sheet width direction of the discharge port, and L is a dimension in the minimum sheet thickness direction of the outermost layer of the laminate. Manufacturing equipment.

Furthermore, 10 <= T / L <= 1000 is satisfied, The manufacturing apparatus of the lamination sheet of Claim 1 characterized by the above-mentioned. Furthermore, the said sheet width direction dimension W is 50 mm <W <300mm, The manufacturing apparatus of the laminated sheet of Claim 1 or 2 characterized by the above-mentioned. Furthermore, the said sheet thickness direction dimension T is T <1000mm, The manufacturing apparatus of the lamination sheet in any one of Claims 1-3 characterized by the above-mentioned. A laminated sheet in which a laminated body is formed by laminating a plurality of types of sheet materials in a larger number of layers than the number of types, and the laminated body is formed into a sheet shape by a die provided downstream of the laminating apparatus. The sheet width direction dimension of the arbitrary cross section perpendicular to the flow path direction in the flow path connecting the laminating apparatus and the die is W, the sheet thickness direction dimension is T, and the discharge port of the die When the sheet width direction dimension is Wd, and the minimum sheet thickness direction dimension of the outermost layer of the laminate is L, the flow path satisfying both the relations of the expressions (1) and (2) is used. Sheet manufacturing method.

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