JP2023001059A - Multilayer laminate merging device - Google Patents

Abstract

To provide a multilayer laminate merging device that overcomes a problem of causing collapse of a laminated structure during transportation of a resin laminate body laminated by a multi-layer lamination device to an inlet and a die; reduces a risk of partition wall deformation due to thermal expansion; and achieves recovery from deformation by a minimum parts replacement even if deformation is caused.SOLUTION: There is provided a multilayer laminate merging device that comprises two or more flow paths in which a molten resin laminate body obtained by alternately laminating 10 or more layers of thermoplastic resin compositions with different compositions are pass through, and a partition wall forming the flow path disappears before reaching an inlet to merge the flow paths into one. The device satisfies the following items (I) and (II). Item (I) is configured in that: when viewed from a longitudinal direction, a rectangular outer wall and a detachable partition plate that divides the outer wall in parallel with a width direction are provided. Item (II) is configured in that: at least one pair of grooves capable of inserting the partition plate into an inner surface of the outer wall in parallel with the width direction are provided.SELECTED DRAWING: Figure 5

Description

TECHNICAL FIELD The present invention relates to a multi-layer lamination confluence device capable of suppressing temperature rise and deformation due to heating, and accompanying changes in the thickness structure of a molten resin laminate.

By laminating multiple resins, multi-layer laminated films can be given performance that cannot be obtained with one type of resin, and the number of laminated layers from 2 to several thousand layers, and the layers from several tens of nanometers to several tens of μm. It has various layer configurations such as thickness. For example, it is possible to form a molten resin laminate having the layer structure as described above by the methods reported in Patent Document 1 and Patent Document 2. A laminated film capable of selectively transmitting/reflecting wavelengths by forming a molten resin laminate in this manner and forming a film while maintaining the laminated structure using a multi-layer lamination/confluence apparatus, such as A heat ray reflective film or the like can be produced (Patent Document 3).

JP-A-2008-68521 JP 2007-307893 A JP 2012-30563 A

However, in the methods of Patent Documents 1 and 2, although it is possible to form a molten resin laminate by laminating the resin composition, the molten resin laminate is excessively laminated. There is a problem that the laminated structure collapses.

Further, in the process of feeding from a multi-layer lamination apparatus to a die or a die, even a precisely laminated molten resin laminate is likely to lose its lamination structure due to a slight deformation of the flow path. Therefore, the multilayer laminated sheet finally obtained may not achieve the desired laminated structure. As a means for reducing the collapse of the laminated structure, Patent Document 3 discloses a method using a multilayer lamination confluence device. It is necessary to heat and raise the temperature to the above temperature, and the flow path deformation occurs due to thermal expansion etc. at that time, which leads to the collapse of the laminated structure. Therefore, in the case of using the multi-layer lamination merging device described in Patent Document 3, the layer thickness of the finally obtained film may differ from the intended design due to collapse of the lamination structure. Further, when the flow path is deformed, it is necessary to replace the multi-layer lamination confluence device, resulting in a large loss of both cost and time.

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems of the prior art, and to provide a multi-layered confluence device capable of reducing quality deterioration due to collapse of the laminated structure and reducing manufacturing costs and time.

In order to solve the above problems, the multi-layer lamination joining device of the present invention has the following configuration. That is, there are two or more channels through which the molten resin laminate in which ten or more layers of thermoplastic resin compositions having different compositions are alternately laminated, and the partition walls forming the channels disappear before reaching the die. 1. A multi-layered confluence device in which the flow paths merge into one, characterized in that the following (I) and (II) are both satisfied. (I) When viewed from the longitudinal direction, it is provided with a rectangular outer wall and a detachable partition plate that divides the outer wall in parallel with the width direction. (II) At least one pair of grooves into which the partition plate can be inserted is provided on the inner surface of the outer wall in parallel with the width direction.

According to the present invention, it is possible to provide a multi-layered confluence device that reduces the risk of partial deformation of partition walls due to thermal expansion, and that can be restored with minimal replacement of parts in the event of deformation.

FIG. 4 is a schematic view of the multi-layered confluence device according to one embodiment of the present invention when observed from the longitudinal direction in a state in which the partition wall portion is not inserted; FIG. 4 is a schematic view of a state in which a partition wall is inserted into a multi-layered confluence device according to an embodiment of the present invention, as observed from the thickness direction; FIG. 10 is a schematic diagram showing a state in which the partition walls are inserted in the multi-layer lamination merging device according to one embodiment of the present invention when observed from the longitudinal direction, and an enlarged schematic view of the groove portion. FIG. 3 is a schematic view of the inlet portion (A) of the molten resin laminate and the outlet portion (B) of the molten resin multilayer laminate of the multi-layer lamination confluence device according to one embodiment of the present invention when observed from the longitudinal direction. 1 is a perspective view of an overall image when assembling a multi-layer lamination joining device according to an embodiment of the present invention; FIG.

Hereinafter, the multi-layer lamination joining device of the present invention will be described in detail. The multi-layer laminating and joining apparatus of the present invention has two or more flow paths through which molten resin laminates in which 10 or more layers of thermoplastic resin compositions having different compositions are alternately laminated are passed, and the flow paths are passed before reaching the die. A multi-layered confluence device in which partition walls to be formed disappear and the flow paths merge into one, characterized by satisfying both the following (I) and (II). (I) When viewed from the longitudinal direction, it is provided with a rectangular outer wall and a detachable partition plate that divides the outer wall in parallel with the width direction. (II) At least one pair of grooves into which the partition plate can be inserted is provided on the inner surface of the outer wall in parallel with the width direction.

The multi-layer lamination confluence device of the present invention has two or more flow paths through which molten resin laminates, in which ten or more layers of thermoplastic resin compositions having different compositions are alternately laminated, pass. Here, the term "multilayer lamination confluence device" refers to a device in which molten thermoplastic resin compositions are alternately laminated and flowed through a plurality of flow paths to align the flows and merge at an outlet. "Different in composition" means that two or more types of molten thermoplastic resin compositions differ in raw materials and their mixing ratios. "A molten resin laminate in which 10 or more layers of thermoplastic resin compositions with different compositions are alternately laminated" means that two types of thermoplastic resin compositions with different compositions (for example, thermoplastic resin compositions A and B) are A molten resin laminate having at least one structure in which 10 or more layers are alternately laminated. As long as the above requirements are satisfied, the number of the laminated structures and the presence or absence of a thermoplastic resin composition (for example, thermoplastic resin composition C) that is different from any of the alternately laminated thermoplastic resin compositions does not matter. No. The expression "having two or more flow paths" means that there are a plurality of flow paths through which the molten resin laminate passes due to partition walls. By adopting such a mode, it is possible to suppress the number of layers to be laminated in the process up to the die, and to reduce the collapse of the layered structure until the liquid is discharged from the die. The method of alternately laminating 10 or more layers of resin compositions having different compositions (that is, the method of forming a molten resin laminate) is not particularly limited, but for example, the method described in Patent Document 1 can be used. can. Further, each thermoplastic resin composition may be composed of a single component or multiple components.

The multi-layered merging device of the present invention is a multi-layered merging device in which the partition walls forming the flow paths disappear before reaching the mouthpiece and the flow paths merge into one. The molten resin laminate that has passed through the multi-layer laminating and joining device is then formed into a thinner sheet with a spinneret and discharged to a cast drum where it is cooled and solidified to become an unstretched sheet. Therefore, "before reaching the spinneret" means upstream of the outlet of the multilayer lamination apparatus. By merging the flow paths into one before reaching the die, the molten resin layered product, which has been divided into a plurality of flow paths and adjusted to improve the lamination accuracy, can be merged into one. As a result, the number of layers of the molten resin layered body can be increased without lowering the layering accuracy.

The multi-layer lamination confluence device of the present invention includes a detachable partition plate that divides the rectangular outer wall portion and the outer wall portion in parallel with the width direction when viewed from the longitudinal direction. When observed from the longitudinal direction, the molten resin laminate is conveyed to the die while keeping the length in the thickness direction constant by providing a rectangular outer wall and a partition plate that divides the outer wall in parallel with the width direction. Therefore, lamination accuracy is improved. Here, the term "detachable" means that the partition plate can be replaced without destroying the multi-layered confluence device.

In addition, since the molten resin laminate heated to a temperature near or above the melting point passes through the flow path formed by the outer wall and the partition wall, the temperature of the multi-layer lamination joining device is raised so as not to solidify the molten resin laminate in the middle. There is a need. In general, the outer walls and partition walls are made of metal, so when these are heated, elastic strain and plastic strain occur mainly in the partition walls due to thermal expansion, and buckling and plastic deformation occur when used once or multiple times. There is When buckling or plastic deformation occurs in the partition wall, the flow path shape of the molten resin laminate changes in the thickness direction, and the laminated structure of the molten resin laminate collapses when passing through the deformed location. The quality of the laminated film may be uneven.

In such a situation, if the outer wall and the partition wall are inseparable, the entire multi-layered confluence device must be replaced with a new one, which increases the manufacturing cost and reduces the manufacturing efficiency. In order to reduce the buckling and plastic deformation of the partition walls, it is conceivable to increase the thickness of the partition walls and design them to resist buckling. In this case, there is a possibility that the flow channel refraction amount of the molten resin layered body becomes large and the layered structure collapses at the part where the partition wall disappears (that is, the confluence part of the molten resin layered body which has passed through each flow path). Furthermore, if the partition wall is thickened, the multi-layer lamination confluence device becomes larger than necessary, which may cause temperature variations inside and outside the device, causing a viscosity difference in the molten resin laminate and collapsing the lamination structure. By making the partition wall detachable, even if buckling or plastic deformation occurs, it is sufficient to replace only the partition wall instead of the entire multi-layer lamination joining device, and maintenance can be performed at low cost.

The multi-layer lamination joining device of the present invention has at least one pair of grooves into which the partition plate can be inserted parallel to the width direction on the inner surface of the outer wall. By adopting such a mode, it becomes easy to form partition walls parallel to the width direction, and furthermore, it is possible to prevent the partition walls from shifting from predetermined positions during use of the multi-layer lamination joining device.

In the multi-layered joining device of the present invention, the thickness of the partition plate is preferably 2 mm or more and 10 mm or less. When the thickness of the partition plate is 2 mm or more, the occurrence of plastic deformation due to buckling can be reduced, and frequent replacement of the partition plate can be avoided. On the other hand, when the thickness of the partition plate is 10 mm or less, the amount of refraction of the flow path at the confluence portion is reduced, and disturbance of the laminated structure of the molten resin laminate can be reduced. From these points of view, the thickness of the partition plate is preferably 3 mm or more and 8 mm or less.

In the multi-layer lamination joining device of the present invention, the width of the groove is equal to or more than the thickness of the partition plate + 0.2 mm and the thickness of the partition plate + 1.0 mm or less, and the length from the bottom of the groove to the bottom of the paired groove is It is preferable that the width direction length of the partition plate is +0.2 mm or more and the width direction length of the partition plate +1.0 mm or less. Since the width of the groove is equal to or greater than the thickness of the partition plate plus 0.2 mm, the partition wall is sandwiched between the grooves in the outer wall due to thermal expansion during heating and temperature rise, and deformation due to expansion of the partition wall in the width direction is prevented. mitigated. Similarly, when the length from the bottom of the groove to the bottom of the paired groove is equal to or greater than the length of the partition in the width direction + 0.2 mm, the partition expands in the width direction, so that the bottom of each groove The deformation caused by the length exceeding the bottom of each pair of grooves is reduced. On the other hand, since the width of the groove portion is equal to or less than the thickness of the partition plate + 1.0 mm, the gap between each groove and the partition plate becomes smaller after the partition plate is fully expanded, and the position of the partition wall is stabilized, and the molten resin laminate is formed. Since the positional displacement of the partition plate due to the pressure is reduced, the laminated structure is stabilized. Similarly, since the length from the bottom of the groove to the bottom of the paired groove is equal to or less than the length of the partition plate in the width direction + 1.0 mm, displacement of the partition plate due to the pressure of the molten resin laminate is reduced. Therefore, the laminated structure is stabilized. From these viewpoints, the width of the groove formed in the outer wall is the thickness of the partition +0.3 mm or more and the thickness of the partition +0.8 mm or less, and from the bottom of each groove to the bottom of each pair of grooves The length of is preferably equal to or more than the width of the partition plus 0.3 mm and less than or equal to the width of the partition plus 0.8 mm.

In the multi-layer lamination confluence device of the present invention, it is preferable that the surfaces of the outer walls and the partition plate that come into contact with the molten resin laminate have an average surface roughness Ra of 0.5 or more and 2.0 or less. When the average surface roughness Ra of the surface is 0.5 or more, the surface tension between the outer wall portion or the partition plate and the molten resin laminate is lowered, so that the flow of the molten resin laminate flowing through the flow path is moderately smooth. As a result, the multi-layered structure of the molten resin layered body is less likely to collapse in the multi-layered merging device. On the other hand, since the average surface roughness Ra of the surface is 2.0 or less, unevenness on the surface of the outer wall and the partition plate is suppressed, so that the multilayer structure of the molten resin laminate collapses in the multilayer joining device. become difficult. From these viewpoints, it is more preferable that the average surface roughness Ra of the surface is 1.0 or more and 1.5 or less. The average surface roughness Ra of the surfaces in contact with the molten resin laminate can be calculated as the average value of the surface roughnesses at the center points of all the surfaces of the outer wall and the partition plate that are in contact with the molten resin laminate. A method for measuring the surface roughness will be described in Examples.

It is preferable that the partition plates of the multi-layered confluence device of the present invention are flat in the thickness direction. Here, the "thickness direction" refers to the direction perpendicular to the surface of the molten resin laminate passing through the multi-layer lamination and confluence device, and "the partition plate is flat in the thickness direction" means that the surface of the partition plate is the base line. Sometimes it means that there are no irregularities or bends with a height or depth (thickness direction length) from the baseline of 1 mm or more. When manufacturing a multi-layer laminated sheet such as a film, there are a multi-layer lamination device, a multi-layer lamination confluence device, and a die in order from the highest position, and usually, from top to bottom, the molten resin composition (then, the molten resin lamination body) is extruded. At this time, if the partition wall is detachable and inserted into the groove as described above, the partition wall moves or falls during assembly, use, and dismantling of the multi-layer lamination joining device. As a structure to prevent the partition from moving or falling, a structure with a hook on the partition is conceivable. It is necessary to take a distance between them, and the thickness of the molten resin laminate may be restricted. From this point of view, it is preferable that the hooks protrude in the direction (width direction) parallel to the surface of the partition plate and that the partition walls are flat in the thickness direction.

When a film is produced using the multi-layer lamination confluence device of the above-described mode, the lamination structure becomes uniform in the width direction, so the quality of the multi-layer laminated film can be improved, and parts can be replaced for maintenance of the device. can be simplified.

Hereinafter, each means constituting the multi-layer lamination joining device of the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic view of a multi-layer lamination merging device according to an embodiment of the present invention, when the outer wall is observed from the traveling direction of the molten resin laminate. FIG. 2 is a schematic view of the state when the partition plate is inserted into the outer wall when observed from the thickness direction, and FIG. 3 is a partially enlarged view of the inserted portion after the partition plate is inserted into the outer wall. FIG. 5 is a perspective view of a state in which the partition plate is inserted into the outer wall. The lamination direction of the molten resin laminate is defined as the thickness direction, the advancing direction of the molten resin laminate is defined as the longitudinal direction, and the direction orthogonal to both the thickness direction and the longitudinal direction is defined as the width direction. Note that the width 8 of the groove, the length from the bottom of the groove 2 to the bottom of the groove 2 paired with the groove 2, and the difference 9 between the width and length of the partition plate 4 are larger than the actual size ratios for the sake of explanation. described in Moreover, since the partition plate becomes a partition by attaching it to the outer wall, the description of both the partition plate 4 and the partition 4 will be used hereinafter in the description using the drawings.

The outer wall 1 of the multi-layered confluence device of the mode shown in FIG. However, a plurality of sets may be provided according to the number of laminations.). As shown in FIG. 2, partition walls 4 are formed by inserting partition plates 4 into paired grooves 2 formed in the outer wall 1 . As shown in FIG. 2, the upper part of the partition plate 4 has a hook portion 5, which is fixed by the recess portion 3 shown in FIGS. By adopting such a mode, it is possible to prevent the partition wall 4 from falling during use or the like.

The state in which the partition plate 4 is inserted as described above is shown in the upper side of FIG. 3, the enlarged view (reference numeral 6) of the vicinity of the groove portion 2 in FIG. 3 is shown in the lower side of FIG. 3, and the perspective view is shown in FIG. The thickness 7 of the partition wall 4 is preferably 2 mm or more and 10 mm or less. With such a thickness, the partition wall 4 is prevented from buckling and deforming in the thickness direction due to the pressure when the temperature rises or when the molten resin laminate passes through, and the molten resin laminate passing through each flow path is suppressed. It is possible to reduce the collapse of the laminated structure when (two in this figure) merge. Further, it is preferable that the width 8 of the groove portion of the outer wall is equal to or larger than the thickness of the partition plate (reference numeral 7) +0.2 mm and equal to or smaller than the thickness of the partition plate +1.0 mm. For example, when the thickness 7 of the partition plate is 3.0 mm, the width 8 of the groove is preferably 3.2 mm or more and 4.0 mm or less. By adopting such a mode, when the temperature of the multi-layer lamination joining device is increased, the partition walls 4 are thermally expanded in the thickness direction and sandwiched between the grooves 2, and the partition walls 4 expand in the width direction to buckle and deform. is suppressed. Further, it is possible to reduce the displacement of the partition wall 4 due to the pressure when the molten resin laminate passes through.

FIG. 4 shows a state in which the molten resin laminate is flowing through the multi-layer lamination confluence device of the above-described mode. In the section from the inlet until the partition wall 4 disappears, the flow path is separated by the partition wall 4, and the thermoplastic resin compositions 10 and 11 (to distinguish between the two, may be referred to as thermoplastic resin A10 and thermoplastic resin B11 for convenience. ) are alternately laminated pass through each channel formed by the outer wall 1 and the partition wall 4 . After that, the partition wall 4 disappears at the downstream part of the flow path, so that the molten resin laminates join each other and eventually reach the outlet. FIG. 4 shows an embodiment in which the molten resin laminate is composed of two types of thermoplastic resin compositions, thermoplastic resin A10 and thermoplastic resin B11, but the number of thermoplastic resin compositions may be three or more. .

The method for producing the multilayer laminate film of the present invention will be described below. The method for producing a multilayer laminated film of the present invention is characterized by forming a laminated structure using the multilayer lamination joining device of the present invention. As described above, the multi-layer lamination merging device of the present invention can reduce the lamination disorder of the molten resin laminate, and therefore, by using the method for producing a multi-layer laminated film of the present invention, the quality of the obtained multi-layer laminated film becomes more uniform. .

The method for producing the multilayer laminated film of the present invention will be specifically described below. However, the following example is an illustration of one aspect of the method for producing a multilayer laminated film of the present invention, and the method for producing a multilayer laminated film of the present invention is not limited thereto. The thermoplastic resins for obtaining the resin layers forming the alternate laminated structure are the thermoplastic resin A and the thermoplastic resin B, respectively. It may be a mixture of resins.

First, thermoplastic resin A and thermoplastic resin B are prepared in the form of pellets, each pellet is dried in hot air or under vacuum as necessary, and then supplied to each of two extruders. Heats and melts at a temperature above the melting point. Next, each melted thermoplastic resin is extruded with a gear pump or the like to make the extrusion rate uniform, and foreign matter and denatured thermoplastic resin are removed through a filter or the like. After that, the thermoplastic resin A and the thermoplastic resin B in a molten state, from which foreign matter has been removed, are fed into the multi-layer stacking apparatus through separate channels. As the multi-layer lamination device, a feed block containing at least two separate members having a large number of fine slits is used. When such a feed block is used, the apparatus does not become extremely large, so foreign matter due to thermal deterioration is small, and even when the number of layers to be stacked is extremely large, stacking can be performed with high accuracy. In addition, lamination accuracy in the width direction is remarkably improved as compared with the conventional technology. In addition, it becomes easy to form an arbitrary layer thickness configuration.

The molten resin laminate obtained by the feed block is sent to the multi-layer lamination confluence device, flows in series in the channel formed by the outer wall and the partition wall, and then merges when the partition disappears to form one large molten resin laminate. become a body. When the thickness of the partition wall is in the range of 2 to 10 mm, it is possible to suppress the distortion of the lamination when the molten resin laminates join together, which is preferable.

Since the molten resin laminate passes through the inside of this multi-layer lamination confluence device, it is necessary to heat it above the melting temperature of each thermoplastic resin. , the partition plate is detachable and provided with a groove into which it is inserted for attachment and detachment. In addition, in order to suppress the deformation of the partition wall due to the thermal expansion of the partition wall when it is crimped and fixed to the groove, the width of the groove is equal to or more than +0.2 mm of the thickness of the partition plate and +1.0 mm or less of the thickness of the partition plate. It is preferable that the length from the bottom of the groove to the bottom of the pair of grooves is the width direction length of the partition plate +0.2 mm or more and the width direction length of the partition plate +1.0 mm or less.

In order to suppress disturbance of the lamination structure of the molten resin laminate passing through the multi-layer lamination confluence device of the present invention, in the outer wall and the partition plate, the average surface roughness Ra of the surface in contact with the molten resin laminate is is preferably 0.5 or more and 2.0 or less.

The molten resin laminate formed into a desired layer structure by the multi-layer lamination/confluence device is then formed into a sheet by a die and then discharged. Then, the molten sheet material discharged from the die is extruded onto a rotating cooling body such as a casting drum, cooled and solidified to form a cast film (unstretched film). At this time, it is preferable to use a wire-shaped, tape-shaped, wire-shaped, or knife-shaped electrode and bring it into close contact with a rotating cooling body such as a casting drum by means of electrostatic force for rapid cooling and solidification. Also preferred is a method in which air is blown out from a slit-shaped, spot-shaped, or planar device and brought into close contact with a rotating cooling body such as a casting drum for rapid cooling and solidification, or a nip roll is brought into close contact with the rotating cooling body to rapidly cool and solidify.

The cast film thus obtained is preferably biaxially stretched as necessary. Biaxial stretching means stretching in the longitudinal direction and the width direction. The stretching may be performed in two directions sequentially or in two directions at the same time. Further, it may be re-stretched in the longitudinal direction and/or the width direction. In particular, in the present invention, it is preferable to use simultaneous biaxial stretching from the viewpoint of suppressing in-plane orientation difference and suppressing surface scratches.

First, the case of sequential biaxial stretching will be described. Here, stretching in the longitudinal direction means stretching for imparting molecular orientation to the casting film in the longitudinal direction, and is usually carried out by a difference in peripheral speed of rolls. This stretching may be performed in one stage or in multiple stages using a plurality of pairs of rolls. The stretching ratio varies depending on the type of thermoplastic resins A and B, but is usually preferably 2 to 15 times, and particularly preferably 2 to 7 times when polyethylene terephthalate is used for thermoplastic resins A and B. be done. Further, the stretching temperature is preferably between the glass transition temperature of the resin having relatively high crystallinity (highly crystalline resin) among the thermoplastic resins A and B and +100°C.

When providing an easy-adhesion layer to a multilayer laminated film, the method of coating and laminating|stacking with a coating material is preferable. As a method of coating the coating agent, there is a method of coating in a process separate from the manufacturing process of the thermoplastic resin film in the present invention, a so-called offline coating method, and a method of coating during the manufacturing process of the thermoplastic resin film in the present invention. There is a so-called in-line coating method in which an easy-adhesion layer is laminated at once. It is preferable to adopt an in-line coating method from the viewpoint of cost and uniformity of coating thickness, and the solvent of the coating liquid used in that case is preferably a water-based solvent from the viewpoint of environmental pollution and explosion prevention. It is the most preferable mode to use.

When forming the easy-adhesion layer by in-line coating, it is preferable to continuously apply a coating agent that constitutes the easy-adhesion layer to a uniaxially stretched thermoplastic resin film (uniaxially oriented film). Examples of methods for applying a coating agent using water as a solvent (aqueous coating agent) include reverse coating, spray coating, bar coating, gravure coating, rod coating, and die coating. It is also preferable to subject the surface to corona discharge treatment or the like before applying the water-based coating agent. This is because the adhesion between the thermoplastic resin film and the coating agent is improved, and the coatability is also improved.

The easy-adhesion layer contains cross-linking agents, antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, organic lubricants, pigments, dyes, organic or inorganic materials, as long as they do not impair the effects of the invention. Particles, fillers, surfactants and the like may be blended.

The subsequent stretching in the width direction refers to stretching for giving molecular orientation in the width direction of the thermoplastic resin film. This stretching is usually performed by conveying the uniaxially oriented film while gripping both ends with clips using a tenter, heating the uniaxially oriented film to preheat it, and then stretching it in the width direction. A water-based coating applied just before the tenter is dried during this preheating. The stretching ratio varies depending on the type of thermoplastic resins A and B, but is usually preferably 2 to 15 times. Especially preferred. The stretching temperature is preferably between the glass transition temperature of the highly crystalline resin and the glass transition temperature of the highly crystalline resin plus 120°C. In order to impart flatness and dimensional stability to the biaxially stretched thermoplastic resin film, the melting point of the resin with the highest content among the resins constituting the thermoplastic resins A and B is kept above the stretching temperature in the tenter. It is preferable to perform the following heat treatment. The thermoplastic resin film heat-treated in this manner is uniformly and gradually cooled, cooled to room temperature, and wound up by a winder. In addition, if necessary, relaxation treatment or the like may be used in combination with the heat treatment and slow cooling.

Next, the case of simultaneous biaxial stretching will be described. In the case of simultaneous biaxial stretching, the casting film thus obtained is continuously coated with a coating agent that constitutes an easy-adhesion layer. Examples of methods for applying a coating agent using water as a solvent (aqueous coating agent) include reverse coating, spray coating, bar coating, gravure coating, rod coating, and die coating. In addition, it is preferable to subject the surface of the casting film to corona discharge treatment or the like before applying the water-based coating material. This is because the adhesiveness between the casting film and the coating agent is improved, and the coatability is also improved.

Next, the casting film coated with the coating agent is guided to a simultaneous biaxial tenter, and conveyed while holding both ends thereof with clips, and stretched simultaneously and/or stepwise in the longitudinal direction and the width direction. As the simultaneous biaxial stretching machine, there are the pantograph system, the screw system, the drive motor system, and the linear motor system. A linear motor system is preferred. Although the stretching ratio varies depending on the type of thermoplastic resins A and B, the area ratio is usually preferably 6 to 50 times, more preferably 8 to 30 times. Particularly in the case of simultaneous biaxial stretching, in order to suppress in-plane orientation difference, the difference in stretching ratio between the longitudinal direction and the width direction should be small (more preferably equal), and the stretching speed should be approximately the same. is preferred. The stretching temperature is preferably between the glass transition temperature of the highly crystalline resin and the glass transition temperature of the highly crystalline resin plus 120°C. In order to impart flatness and dimensional stability to the biaxially stretched multilayer laminated film, it is preferable to subsequently heat-treat the film in a tenter at a temperature higher than the stretching temperature and lower than the melting point of the highly crystalline resin. In order to suppress the distribution of the main orientation axis in the width direction during this heat treatment, it is preferable to instantly relax the film in the longitudinal direction immediately before and/or after entering the heat treatment zone. The multi-layer laminate film heat-treated in this manner is uniformly and slowly cooled, cooled to room temperature, and wound up by a winder. In addition, if necessary, relaxation treatment may be performed in the longitudinal direction and/or the width direction during slow cooling after the heat treatment. It is also preferred to apply a momentary longitudinal relaxation treatment immediately before and/or after entering the heat treatment zone.

The multi-layer laminated film thus obtained is cooled in the subsequent transportation process, once wound up as an intermediate roll by a wide winding machine, and then cut into the required width and length by a slitter to be the final product. .

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples. The multi-layer lamination apparatus and partition plate used in each example and each comparative example, and evaluation methods for each item are as follows. In addition, for the purpose of evaluating buckling and deformation due to thermal expansion of the multi-layer lamination confluence device due to repeated use, the evaluation of the finally obtained film was performed six times in total. and do.

<Production of multilayer laminated film>
[Resin extrusion/multilayer lamination device (process before multilayer lamination confluence device)]
Thermoplastic resin A and thermoplastic resin B are melted at 280° C. in separate vented twin-screw extruders, and then passed through a gear pump and a filter to form two separate members having 10 slits. Two molten resin laminates are laminated in a multi-layer lamination device (feed block). The thermoplastic resin A and the thermoplastic resin B are alternately laminated, and the lamination ratio obtained by dividing the total thickness of the layers made of the thermoplastic resin A by the total thickness of the layers made of the thermoplastic resin B is 1.00. make it

[Multilayer stacking confluence device]
The multi-layer lamination confluence device used has two flow paths formed by an outer wall and one partition wall up to just before the mouthpiece. The two molten resin laminates laminated in the multilayer lamination apparatus (feed block) described above are conveyed through separate channels toward the die, and the two molten resin laminates are merged just before reaching the die. The temperature of this multi-layer lamination merging apparatus is raised to 280° C. before extruding each thermoplastic resin, and the temperature is lowered to normal temperature after the completion of the production of the multi-layer laminated film.

[Piece-to-winding (post-process from multi-layer lamination confluence device)]
The molten resin multilayer laminate ejected from the die is adhered to a casting drum maintained at a surface temperature of 25° C. by applying static electricity and rapidly solidified to obtain a cast film. After heating the obtained cast film with a roll group set at 80° C., the cast film was stretched 3.3 times in the longitudinal direction while being rapidly heated from both sides by a radiation heater in a stretching section of 100 mm, and then cooled once. to obtain a uniaxially stretched film. Next, both sides of the uniaxially stretched film are subjected to corona discharge treatment in the air to set the coating tension on both sides to 55 mN/m, and the easily adhesive layer Composition-I is applied to both sides with a #4 meta bar. Thereafter, the obtained uniaxially stretched film is introduced into a tenter, preheated with hot air at 100°C, and stretched 3.5 times in the transverse direction at a temperature of 120°C. The stretched film was directly heat-treated in a tenter with hot air at 240°C, then subjected to a relaxation treatment of 7% in the width direction at the same temperature, then cooled to room temperature and wound with a winder to a thickness of 110 µm. , a multilayer laminated film having a width of 3600 mm, a length of 20 m, and 19 layers.

<Evaluation of each item>
[Distortion of partition wall]
After manufacturing the laminated film for the 1st to 6th times, the distortion of the partition wall portion of the multi-layered lamination/confluence device is checked. When the partition wall is distorted, it becomes arcuate, so the distance from the vertex to the original position is L, and the amount of distortion is measured.
○: L = 0 (no distortion)
△: 0<L<2 (mm)
×: 2≦L (mm).

[Evaluation of laminated structure]
Five measurement points in parallel with the width direction from the laminated film produced for the sixth time (central portion, ±600 mm portion, ±1200 mm portion). A point.The ±1200 mm part can be interpreted in the same way.), Observe the thickness direction cross section at each measurement point with a transmission electron microscope (TEM), and use the image analysis software "Image-Pro Plus (Hakuto Co., Ltd.) The layer thickness distribution is obtained by image processing using "Made in Japan". From the arbitrarily selected one of the outermost layers, the 1st to 20th layers are selected in order, and the variation from the average thickness at each measurement point of the 1st layer to the average thickness at each measurement point of the 20th layer. Check for variability. Based on the variation in the thickness of each layer obtained, evaluation is made according to the following criteria. The calculation formula used for the variation is as follows, where dn is the thickness of the n-th layer.
Variation=|dn/(Σdn/5)|*100
(However, Σdn is the 5-point dn total value of the central part, ±600 part, and ±1200 part)
A: Variation is less than 8% for all layers.
◯: Variation is 8% or more and less than 10% for one or more layers.
Δ: Variation is 10% or more and less than 15% for one or more layers.
x: Variation of 15% or more in one or more layers.

[Evaluation of exchange frequency]
During the 1st to 6th evaluations, if the partition wall is deformed, a new facility equivalent to that before the deformation is installed, and the number of replacements is evaluated as follows. That is, the number of times marked with an x for strain of the partition wall is the number of replacement times.
○: 0 times △: 1 time ×: 2 times or more.

[Evaluation of replacement cost]
When the partition wall is deformed, the cost to restore the equipment to the same condition as before the deformation is evaluated as follows.
○: Replace only the bulkhead (low cost due to flatness)
△: Only the partition part is replaced (because it is three-dimensional, it is somewhat expensive)
×: Replacement of the entire multi-layered merging device (the entire device is very expensive).

[Comprehensive evaluation]
If the laminated structure is ⊚, ◯, or Δ, it is accepted (that is, A to D below), and if it is ×, it is rejected (that is, E below). Furthermore, for each item of laminate structure, number of exchanges, and exchange cost, ⊚ is calculated as 3 points, ○ as 2 points, Δ as 1 point, and × as 0 points.
A: The sum of each item is 7.
B: The laminate structure is ⊚, and the total of each item is less than 7.
C: Laminated structure is ◯, and the total of each item is 6.
D: The laminate structure is ◯ or Δ, and the total of each item is less than 6.
E: Laminated structure is x.

(Example 1)
With regard to the [Multilayer Lamination Merging Apparatus], two molten resin laminates are merged using the equipment conditions described in Example 1 in Table 1 to produce a molten resin multilayer laminate six times. The evaluation is shown in Table 1. The partition walls that separate the two molten resin laminates until they merge are made to be individually insertable. In Table 1, "distance between groove bottoms (mm)") and the average surface roughness Ra of the surfaces of the outer walls and partition plates that come into contact with the molten resin laminate are the values shown in Table 1, respectively. Ra is measured by the following procedure using a surface roughness tester "SURFTEST SJ210 0.75 mN type (manufactured by Mitsutoyo)". 1 point (total of 8 points) in the width direction and the longitudinal direction of the surface in contact with the molten resin laminate of each flow path is taken, and a surface roughness measuring machine is installed in parallel with the longitudinal direction to measure Ra, Let the average value of the obtained values be the Ra concerned. In addition, the sheet width direction dimension W of an arbitrary cross section perpendicular to the flow path direction of the molten resin multilayer laminate obtained at the outlet of the multilayer lamination joining device is 190 mm, the sheet thickness direction dimension T is 32 mm, and the sheet at the discharge port of the die The width dimension Wd is 1000 mm.

(Examples 2 to 9)
A molten resin multilayer laminate is produced six times in the same manner as in Example 1, except that the dimensions and Ra of the partition plates and grooves are set to the values shown in Table 1, and each item is evaluated. The evaluation is shown in Table 1.

(Example 10)
Six molten resin multilayer laminates are produced in the same manner as in Example 1, except that the hooks of the partition plates are formed to protrude in the thickness direction, and each item is evaluated. The evaluation is shown in Table 1.

(Comparative example 1)
The same as in Example 1, except that one partition portion separating the two molten resin laminates described in Example 1 from each other until they merge and the outer wall are integrated, and the dimensions, Ra, are set as shown in Table 1. Then, a molten resin multilayer laminate is produced six times, and each item is evaluated. The evaluation is shown in Table 1. In addition, since it is an integral type, there is no groove.

The flatness of the partition plate in the table is indicated by "X" when the hook portion of the partition plate is raised in the thickness direction, and by "○" when there is no raised shape.

It is possible to provide a multi-layer lamination confluence device capable of reducing quality deterioration due to collapse of the lamination structure and reducing manufacturing cost and time. A high-quality laminated film capable of selectively transmitting/reflecting wavelengths can be produced by using the multi-layer lamination/confluence apparatus of the present invention.

1 Outer wall 2 Groove 3 Hollow 4 Partition plate 5 Hook 6 Enlarged view near groove 2 7 Thickness of partition plate 8 Width of groove 9 Difference between length to bottom of each groove and width of partition plate 10 Thermoplastic Resin composition (thermoplastic resin A)
11 Thermoplastic resin composition (thermoplastic resin B)

Claims (6)

Having two or more flow paths through which molten resin laminates in which ten or more layers of thermoplastic resin compositions having different compositions pass alternately,
A multi-layered confluence device in which the partition walls forming the flow paths disappear before reaching the mouthpiece and the flow paths merge into one, characterized by satisfying both the following (I) and (II). and a multi-layer lamination merging device.
(I) When viewed from the longitudinal direction, it is provided with a rectangular outer wall and a detachable partition plate that divides the outer wall in parallel with the width direction.
(II) At least one pair of grooves into which the partition plate can be inserted is provided on the inner surface of the outer wall in parallel with the width direction. 2. The multi-layer lamination joining device according to claim 1, wherein the thickness of said partition plate is 2 mm or more and 10 mm or less. The width of the groove is the thickness of the partition plate + 0.2 mm or more and the thickness of the partition plate + 1.0 mm or less, and the length from the bottom of the groove to the bottom of the paired groove is the thickness of the partition plate. 3. The multi-layer confluence device according to claim 1, wherein the length in the width direction is +0.2 mm or more and the length in the width direction of the partition plate is +1.0 mm or less. 4. The multi-layer lamination joining device according to any one of claims 1 to 3, wherein the outer wall portion and the partition plate have an average surface roughness Ra of 0.5 or more and 2.0 or less of the surfaces that come into contact with the molten resin laminate. . 5. The multi-layer lamination joining device according to claim 1, wherein said partition plate is flat in the thickness direction. A method for producing a multilayer laminated film, wherein a laminated structure is formed by using the multilayer lamination joining apparatus according to any one of claims 1 to 5.

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