JPH02227232A - Manufacture of liquid crystal polymer film - Google Patents

Abstract

PURPOSE:To improve the balance of flatness and mechanical properties by stacking both of upper and lower surfaces by means of a thermoplastic polymer layer on a feed block type coextrusion device, also stacking a plurality of liquid crystal polymer layers between and through the thermoplastic polymer layers and molding simultaneously a plurality of thermotropic liquid crystal polymer films. CONSTITUTION:A liquid polymer, a thermoplastic polymer A having no bonding properties with the liquid crystal polymer and a thermoplastic polymer B having no bonding properties with the liquid crystal polymer are guided respectively to a feed block 1 by three units of extruders, and the polymer A, polymer B and LCP are stacking on a multi-layer fluid laminated section of the feed block in five layer constitution, and then the same is guided to a T-die 7 of a single manifold and extruded in the film shape. Then, the same is passed through a cooling roll and two outer layers 13, 14 constituted of the polymer A are peeled off the film of five layer constitution to provide a film of three layer constitution, and then the films of three layer constitution are peeled off respectively, and two liquid crystal polymer films 11, 12 are released, and then a polymer B film 15 is released.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a method for producing a thermotropic liquid crystalline polymer (hereinafter referred to as liquid crystalline polymer) film that can form an anisotropic melting layer during thermal melting.

More specifically, the present invention relates to a method for producing a liquid crystal polymer film having improved physical properties that further improve the performance of conventional liquid crystal polymer films.

(b) Prior art In recent years, various polymers have been developed, including high-strength films, high-elastic films, flexible films, adhesive films, transparent films, conductive films, light-shielding films, gas barrier films, heat-resistant films, and chemical-resistant films. A variety of films have been developed, including sex films and composite films.
It is used for various purposes.

Liquid crystalline polymers have mechanical properties, dimensional stability, heat resistance,
Due to its excellent chemical stability, gas barrier properties, and good electrical properties, it has attracted attention as a raw material polymer for films that meet the performance requirements of various uses, and various development studies are being conducted in various fields. There is. However, when it comes to film forming, the Special Publication No. 60-4228? By using the high degree of orientation of molecular chains, which is a characteristic of liquid crystal polymers, we mold liquid crystal polymers into a film while applying a draft.
As shown in the method of obtaining highly elastic split fibers by dividing the polymer, it is difficult to use the liquid crystal polymer as a film due to the high degree of orientation of the molecular chains of the liquid crystal polymer. Since the strength in the direction (hereinafter referred to as TD direction) becomes extremely weak, melt extrusion molding is extremely difficult.

Various methods have been studied to improve the problem that the strength of the liquid crystalline polymer film in the TD force direction is extremely weak. For example, a method of obtaining a two-wheel oriented film by increasing the blow-up ratio using an inflation method (JP-A-56-46728, JP-A-61
-102234), by rotating the ring die using the inflation method in a direction perpendicular to the film take-up direction (
Method of applying shear core force to the MD force direction (hereinafter referred to as MD force direction)
JP-A-562127, JP-A-63-173620)
, A method of installing a plate-like porous body having a large number of heatable slits inside a T Gui (Japanese Patent Application Laid-Open No. 58-59818), T
There are methods of laminating anisotropic films molded by a die method or an inflation method (JP-A-52-109578, JP-A-5831718, JP-A-61-89816, JP-A-62-95213), etc. . However, an industrially useful method for producing a film with balanced mechanical properties that does not easily split and fibrillate due to external force in the TD force direction has not been established. A method for industrially producing a film with good appearance, thickness accuracy, and balanced mechanical properties for practical use with good reproducibility has not yet been completed.

According to experiments conducted by the present inventors, when a monolayer film of a liquid crystalline polymer is formed by the T-die method or the inflation method, due to the characteristics that the molecular structure is rigid and there is little entanglement between molecular chains, ■ Solidified material peels off from the surface layer of the liquid crystalline polymer molten fluid and accumulates at the tip of the die where high shear core force acts. ■ The highly molecularly oriented skin layer on the film surface becomes fibrillated due to stretching during withdrawal. A problem has arisen in that the surface of the formed film becomes rough and cannot be smoothed due to peeling and other factors. In addition, for example, when trying to form a thin film of 50 μm or less, stretching at a high sound rate is required, ① the problem of peeling of the skin layer on the surface of the film, ③ the problem of forming split fibers of the film due to advanced molecular orientation, It has become clear that it is difficult to form thin films of 50 μm or less because of this.

One method to improve these problems is to use a three-layer coextrusion die, in which the middle layer is made of a liquid crystalline polymer, and the outer layer is made of two types of polymers: a liquid crystalline polymer and a non-adhesive thermoplastic polymer (polycarbonate, polyolefin). A method described in JP-A-63-31729 has been proposed in which a three-layer film is formed and then the outer layer is peeled off to take out the middle layer of the liquid crystalline polymer film.

The three-layer co-extrusion die described in JP-A No. 63-31729, which is included in the multi-layer extrusion die generally called a multi-manifold die, can form a film with high thickness accuracy for each layer when specially designed according to the raw materials used. be able to. Therefore, when a liquid crystalline polymer film is molded using the three-layer coextrusion die described in JP-A No. 63-31729, the surface of the liquid crystalline polymer film is protected by the outer layer of thermoplastic polymer, resulting in high thickness accuracy and appearance. , a liquid crystalline polymer film with good surface flatness can be obtained.

(c) Problems to be Solved by the Invention However, according to experiments conducted by the present inventors, the method using the multi-manifold die described above produces a liquid crystalline polymer film with high thickness accuracy and good appearance and surface flatness. Although obtained, the strength in the TD force direction, which is a drawback of liquid crystalline polymer films, is not sufficient for practical use. This is because, in the manifold die described in JP-A No. 63-31729, there is a position within the die where the resin merges, and after the flow is widened over the entire width of the die within the manifold, the resin merges and is discharged through the slit. Because of this, the liquid crystalline polymer is highly oriented within the die due to the high shear core force during flow, similar to that in conventional single-layer extrusion dies, and then merges with the thermoplastic polymer in the outer layer. Therefore, the drawback that the anisotropy of the film becomes strong and the strength in the TD force direction becomes weak has not been solved.

In addition, in the method described in JP-A-63-31729, in which a three-layer film is molded, the outer layer is peeled off, and the intermediate layer liquid crystalline polymer film is taken out to produce a product, the product is
It requires two layers of non-products for each layer, resulting in very low production efficiency. Furthermore, in the multilayer extruded gou called multi-manifold gou, which was disclosed as a specific three-layer coextruded gou in the above-mentioned Japanese Patent Application Laid-Open No. 83-31729, the gou structure becomes too yIIll, making it difficult to multilayer with four or more layers. Therefore, it is not possible to simultaneously manufacture two or more liquid crystalline polymer films and increase production efficiency by molding a multilayer film containing two or more liquid crystalline polymer layers.

The purpose of the present invention is to establish an economical and industrial manufacturing method for a liquid crystalline polymer film with high thickness accuracy, good appearance and surface flatness, and a balance of mechanical properties for practical use with good reproducibility. It's about doing.

(d) Means for Solving the Problems As a result of extensive studies, the present inventors discovered that the above object could be achieved by using a feed block coextrusion method, leading to the present invention.

Here, in the feed block co-extrusion method, a feed block is provided before feeding multiple resins into the goo body, and a merging flow is prevented from forming in advance in this part, and then the flow is widened by feeding them into a normal single manifold die. This is an extrusion method, which is different from the above-mentioned manifold die method. As far as the present inventors know, producing a liquid crystal polymer film using such a feedblock coextrusion method is completely unknown.

Thus, the present invention provides a feed block type coextrusion device for coextruding a thermotropic liquid crystalline polymer and a thermoplastic polymer, with thermoplastic polymer layers on both upper and lower surfaces, and a plurality of liquid crystalline polymer layers in between. The present invention provides a method for producing a liquid crystalline polymer film, characterized in that a plurality of thermotropic liquid crystalline polymer films are simultaneously molded by supplying the thermotropic liquid crystalline polymer films so as to be laminated through the film.

The liquid crystalline polymer used in the present invention means a thermoplastic polymer exhibiting liquid crystallinity in the melt phase, such as wholly aromatic or non-wholly aromatic polyester, aromatic-aliphatic polyester, aromatic polyazomethine. , aromatic polyester carbonate, wholly aromatic or non-wholly aromatic polyester amide, etc., but are not limited thereto. Among these, wholly aromatic polyester-based and wholly aromatic polynistylamide-based liquid crystal polymers can be synthesized from aromatic diols, aromatic diamines, aromatic dicarboxylic acids, aromatic hydroxy acids, and the like. Examples of aromatic-aliphatic polyester liquid crystalline polymers include copolymers of polyethylene terephthalate and hydroxybenzoic acid. Examples of aromatic polyazomethine-based liquid crystal polymers include polytrilo-2-methyl-1,4-phinidine-nitriloethyridine-1,4-phenylenemethylidine), polytrilo-2-chloro-1 , 4-phinitrilomethylidine-1,4-phenylenemethylidine), and the like. Examples of aromatic polyester carbonate-based liquid crystalline polymers include polymers composed of p-oxybenzoyl groups, p-dioxyphenyl groups, dioxycarbonyl groups, and terephthalic acid groups. Moreover, as an example of aromatic polyester amide, for example, a copolymer of p-aminobenzoic acid and polyethylene phthalate can be mentioned.

The thermoplastic polymers forming the two outer layers of the multilayer film used in the present invention can be those that do not exhibit substantial adhesion to the liquid crystal polymer layer during molding, such as polyethylene, polypropylene, polycarbonate, polyethylene terephthalate, etc. , polybutylene terephthalate,
Examples include aromatic polyester, polyacetal, polyetherimide, polyether ether ketone, polyether sulfone, polysulfone, polyphenylene sulfide, polyphenylene ether, and the like.

The polymer film of the present invention is formed by a feedblock coextrusion method using a T-die, and has a multilayer structure of five or more layers, including at least two liquid crystalline polymer layers, and two outer layers of thermoplastic polymer. This is something that can be obtained from film. Film forming by the conventional multi-manifold die coextrusion method using a T-die involves extruding a liquid crystalline polymer and a thermoplastic polymer by melting them from an extruder into a T-die, expanding and merging them in the T-die, and extruding the molten polymer through a slit. This is a method of extruding and molding into a film. At this time, the molten polymer, especially the liquid crystalline polymer, undergoes molecular orientation in the direction of MD force, which is not affected by the widening of extrusion molding. The anisotropy of liquid crystal polymer film increases due to molecular orientation, and when it is divided into split fibers or molded as a single layer, the highly oriented film surface layer (skin layer) peels off and the film surface Appearance and flatness deteriorate. The high degree of molecular orientation that causes these problems is caused by the action of high shear stress due to the flow during widening within the T-die.

In the present invention, in the feed block section installed before entering the T-die, the two outer layers are thermoplastic polymer layers, and the remaining intermediate layer is a liquid crystal polymer layer and a thermoplastic polymer layer, which are appropriately arranged and laminated. By doing so, a molten polymer fluid having a multilayer structure in which both surfaces of the liquid crystalline polymer layer are protected is produced. Here, the number of layers of the multi-layered molten polymer fluid can be freely selected from 5 or more according to the purpose, and the structure of the layers can also be freely selected according to the purpose. The molten polymer fluids merged and laminated in the feed block section are sent to a T-die and extruded into a film through a slit. In this case, unlike the method using a multi-manifold die,
Since the width is widened after merging, the liquid crystalline polymer layer is protected by the outer thermoplastic polymer layer within the T-die, and high shear stress due to flow does not directly act on it. therefore,
A liquid crystalline polymer film with low molecular orientation of the liquid crystalline polymer, low anisotropy, and sufficient strength in the TD force direction can be obtained. In addition, Feedblock is a company developed by the Dow Company in the United States.
This is a device for laminating molten polymers used in coextrusion multilayer film manufacturing devices commercially available from Egan, Cloeren, and others.

The thermoplastic polymers forming the two outer layers and the several inner layers of the multilayer film of the invention may themselves all be the same or may consist of a plurality of types.

In other words, the thermoplastic polymers used in the multilayer film can be freely selected and combined depending on the purpose. However, due to the structure of the feedblock, the absolute number of laminated layers is normally suitable to be within 9 layers, and it is recommended to set the number of layers to 5 to 7 layers, that is, 2 to 3 liquid crystal polymer layers. Are suitable.

The thickness of the multilayer film in the present invention is not particularly limited, but is preferably 10 μm to 1000 μm. The thickness ratio of each layer can be freely selected depending on the purpose. Then, by peeling off the liquid crystal polymer layer and the thermoplastic polymer layer after forming the multilayer film, two or more liquid crystal polymer films can be obtained from one multilayer film.

According to the present invention, by molding a liquid crystalline polymer film using a feedblock coextrusion method, the film not only has good appearance and surface flatness as well as the conventional method using a multi-manifold die. Furthermore, it becomes possible to industrially produce a liquid crystalline polymer film that has a balance of low anisotropy, TD force direction strength, and sufficient mechanical properties for practical use. In addition, in the film manufacturing method of the present invention, two or more liquid crystalline polymer films for practical use can be manufactured at the same time, so production efficiency is much higher than in conventional methods.

Below, the method for manufacturing a liquid crystal film of the present invention will be explained based on the accompanying drawings.

FIG. 1 shows an embodiment of the film manufacturing method of the present invention, page 3, and shows the steps after the feed block. In this example, three extruders are used, and a liquid crystal polymer, a thermoplastic polymer A that does not have adhesive properties with the liquid crystal polymer, and a thermoplastic polymer B that does not have adhesive properties with the liquid crystal polymer are fed into the feed block from each extruder. After extruding it inward, it is extruded out through a T-die to form a 5-layer structure containing two layers of liquid crystalline polymers made of three types of polymers, as shown in Figure 2.
This shows the case of molding a film with a layered structure. In the figure,
1 indicates a 5-layer combined feedblock, and 7 indicates a single manifold T-die. Also, in the figure,
2.6 is polymer A flow path, 4 is polymer B flow path, 3.5
8 indicates a liquid crystal polymer flow path, 8 is a pressure roll, 9 is a pressure roll, and 9 is a pressure roll.
10 is a five-layer film, IO is a cooling roll, 11.12 is a liquid crystal polymer film, 13. ．． Reference numeral 14 indicates a polymer A film, and 15 indicates a polymer B film.

In this embodiment, the extrusion fi of A (not shown)
Thermoplastic polymer A that has no adhesive properties with liquid crystalline polymers
(Polymer A) is extruded from an extruder B (not shown), and a thermoplastic polymer B (Polymer A) which has no adhesive properties with the liquid crystal polymer is
Polymer B) is extruded, liquid crystalline polymer (LCP) is extruded from extruder C (not shown), and each polymer is fed to feed pipe A.

B, C (not shown) feed block l
lead to. This results in feed pipes A and B.

In the multilayer flow stacking section in the feed block 1 continuing from C, polymer A, polymer B, and LCP shown in FIG. 2 are laminated to form five layers. The 5-layer molten polymer is introduced into a single manifold T-dia connected to a feedblock and extruded into a film. Next, after passing through a cooling roll, the two outer layers of Polymer A are peeled off from the five-layer film to form a three-layer film, and then each of the three-layer films is peeled off to form two outer layers.
A sheet of liquid crystalline polymer film 11 and 12 is taken out.

In the film manufacturing method of the present invention, the extrusion temperature of the liquid crystalline polymer, etc. is a temperature equal to or higher than the softening point of the polymer. For example, in the case of liquid crystalline polymers, 200°C to 400°C,
Preferably, it is extruded at a temperature of 240°C to 340°C. Here, the softening point is the lowest temperature at which a liquid crystalline polymer or the like can melt and flow. The extrusion temperature of the thermoplastic polymer forming the outer layer when coextruding with the liquid crystalline polymer is preferably higher than the extrusion temperature of the liquid crystalline polymer by -50°C. A more preferable extrusion temperature is higher than the extrusion temperature of the liquid crystalline polymer minus 50°C and lower than the extrusion temperature of the liquid crystalline polymer plus 50°C. Furthermore, molding conditions such as the temperature of the cooling roll and the speed at which the film is taken up can be freely set depending on the purpose.

(e) Effects of the Invention By using the feedblock coextrusion method of the present invention, it is possible to economically and industrially produce a liquid crystalline polymer film that is suitable for practical use, has good appearance and surface flatness, and has well-balanced mechanical properties. can be obtained.

(The following is a blank space) (F) Examples The present invention will be described in more detail below based on examples.

Example! Using the apparatus shown in FIG. 1 as a film manufacturing apparatus, a film having the structure shown in FIG. 2 was molded.

Pellets of liquid crystalline polymer (manufactured by Polyplastics Co., Ltd., trade name Vectra A900) were dried in advance at a temperature of 150°C for 8 hours and extruded from extruder C at 290°C. 2
Polymer A (polypropylene manufactured by Ube Industries, Ltd., trade name: UBE Polypro T) is a thermoplastic polymer that does not have adhesive properties with liquid crystal polymers.
F905), Polymer B (Ube Industries, Ltd.), a thermoplastic polymer with no adhesive properties with the liquid crystalline polymer forming the central layer.
Polypropylene manufactured by Co., Ltd., trade name UBE Polypro TF
905) were extruded at 260°C from extruder A and at 260°C from extruder B, respectively. Then, a film with a five-layer structure shown in FIG. 2 containing two layers of liquid crystalline polymer is extruded from a T-die, and after peeling off the two outer layers formed by polymer A, each film with a three-layer structure is further peeled off. 2
A sheet of liquid crystalline polymer film was taken out and pulled at a speed of 5 m/min. 2 polymer outer layers, 8 polymer layers, 2
The thickness of each of the two liquid crystalline polymer layers is 157 cm.
oo, 15 μm% io μm, 30 μm 130 μm. The MD force direction TD force direction tensile strength of the obtained liquid crystalline polymer film was 4200 Kg/can, respectively.
', 1400Kg/am'', and had excellent tear resistance as well as good appearance and surface flatness.In addition, there was no difference in performance between two liquid crystal polymer films produced at the same time. Therefore, the production efficiency was twice as high as that of Comparative Example 1, which will be described later.

Example 2 Using the apparatus shown in FIG. 1 as a film manufacturing apparatus, a film having the structure shown in FIG. 2 was molded.

Pellets of liquid crystalline polymer (manufactured by Polyplastics (Aji), trade name Vectra A900) were dried in advance at a temperature of 150°C for 8 hours, and extruded from extruder C at 290°C. 2
Polymer A (low-density polyethylene manufactured by Ube Industries, Ltd., trade name: UBE polyethylene B128), which is a thermoplastic polymer that does not adhere to liquid crystal polymers, is used to form two outer layers, and it adheres to liquid crystal polymers that form the central layer. Polymer B (polypropylene manufactured by Ube Industries, Ltd., trade name: UBE Polypro T,
F905) were extruded from extruder A at 250°C and from extruder B at 260°C, respectively. Then, a film with a five-layer structure shown in FIG. 2 containing two layers of liquid crystalline polymer is extruded from a T-die, and after peeling off the two outer layers formed by polymer A, each film with a three-layer structure is further peeled off. Two liquid crystalline polymer films were taken out and pulled at a speed of 5 m/min. 2 polymer outer layers, 8 polymer layers,
The thickness of each of the two liquid crystal polymer layers is 10
μm, 10 μm, 110 μm, 130 μm, 130 μm. MD force direction TD of the obtained liquid crystalline polymer film
The tensile strength in the force direction is 4100 Kg/am'' and 1
The tear resistance was 401 Kg/as', and the tear resistance was excellent, and the appearance and surface flatness were also good. Furthermore, there was no difference in performance between the two liquid crystalline polymer films produced at the same time, and the production efficiency was 22% compared to Comparative Example 1.
improved twice.

Example 3 Using the apparatus shown in FIG. 1 as a film manufacturing apparatus, a film having the structure shown in FIG. 2 was molded.

Pellets of liquid crystalline polymer (manufactured by Polyplastics Co., Ltd., trade name Vectra A900) were dried in advance at a temperature of 150°C for 8 hours and extruded from extruder C at 290°C. 2
Polymer A (polycarbonate manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: Niepiron 93000), which is a thermoplastic polymer that does not have adhesive properties with liquid crystal polymer, was dried in advance at a temperature of 120°C for 4 hours to form two outer layers. , Polymer B (polycarbonate manufactured by Mitsubishi Gas Chemical 1, trade name: Nipilon S 3000), which is a thermoplastic polymer that does not have adhesive properties with the liquid crystalline polymer forming the center layer, was dried in advance at a temperature of 120 ° C. for 4 hours. It was extruded at 310°C from extruder A and at 310°C from extruder fiB, respectively. Then, a film with a five-layer structure shown in FIG. 2 containing two layers of liquid crystalline polymer is extruded from a T-die, and after peeling off the two outer layers formed by polymer A, each film with a three-layer structure is further peeled off. Two liquid crystalline polymer films were taken out and pulled at a speed of 5 m/min. The thickness of each layer of the two outer polymer layers, the eight polymer layers, and the two liquid crystal polymer layers is 15 um% 15 μg +,
IOH, 30 μm, 30 μm.

The MD force direction TD force direction tensile strength of the obtained liquid crystalline polymer film was 3900 Kg/cm' and 150 Kg/cm', respectively.
0 Kg/co+'', and had excellent tear resistance, as well as good appearance and surface flatness.

Furthermore, there was no difference in performance between the two liquid crystalline poly films produced at the same time, and the production efficiency was doubled compared to Comparative Example 1.

Example 4 Four extruders (A, B,
A film having a seven-layer structure shown in FIG. 3 was formed using an apparatus using a feed block capable of forming a film having a seven-layer structure.

Pellets of liquid crystalline polymer (manufactured by Polyplastics (special), trade name Vectra A900) forming the second, fourth, and sixth layers in FIG. 3 were dried in advance at a temperature of 150°C for 8 hours. , extruder B and extruder at 290°C. Polymer A forming the first layer and seventh layer in FIG.
(Low density polyethylene manufactured by Ube Industries, Ltd., trade name: UBE)
812 g of polyethylene), Polymer C, which is a thermoplastic polymer forming the third and fifth layers in Figure 3 (polypropylene manufactured by Ube Industries, Ltd., trade name: UBE Polypro T)
F 905) were extruded at 250° C. from extruder A and at 260° C. from extruder C, respectively. Then, a film with a seven-layer structure shown in Figure 3 containing three layers of liquid crystalline polymer was
After extruding from a die and peeling off the first layer and seventh layer formed by polymer A, the second layer and sixth layer are peeled off and two liquid crystalline polymer films are taken out and pulled off at a speed of 5 m/min. Ta. Furthermore, each of the three-layer films was peeled off, and the four-layer liquid crystal polymer film was taken out.
I picked it up in minutes.

The number of layers for the third and fifth polymer layers in Figure 3 is 7 each.
μm, 7 μm1 Similarly, the second and sixth liquid crystal polymer layers are 15 μm and 15 μm, respectively. Similarly, the third and fifth layers are
Each of the polymer C layers had a thickness of 10 μm and 10 μm, and the fourth liquid crystal polymer layer had a thickness of 18 μm. The MD force direction TD force direction tensile strengths of the liquid crystalline polymer films obtained from the second layer and the sixth layer in FIG. 3 are 4100 Kg/am'' and 1400 Kg/am'', respectively.
The MD force direction TD force direction tensile strength of the liquid crystalline polymer film obtained from the fourth layer in FIG. 3 is 4000, respectively.
Kg/cm" and 1450 Kg/am", and the tear resistance was excellent, and the appearance and surface flatness were excellent. Furthermore, since two liquid crystalline polymer films were manufactured at the same time, the production efficiency was improved three times compared to Comparative Example 1.

Comparative Example 1 Three extruders (A, B,
C) and a multi-manifold type T die for three-layer coextrusion were used, and an apparatus similar to the method described in JP-A-83-31729, which can peel two outer layer films of a three-layered film, was used. Pellets of liquid crystalline polymer (manufactured by Polyplastics Co., Ltd., trade name Vectra A900) were dried in advance at a temperature of 150°C for 8 hours, and then
Extruded at °C. The polymer forming the outer layer is a liquid crystal polymer and a non-adhesive thermoplastic polymer (Ube Industries, Ltd.).
Polypropylene manufactured by UBE Polypro TF (product name: UBE Polypro TF)
905) was extruded from extruder A and extruder C at 260°C. Then, a three-layer film with a liquid crystalline polymer as an intermediate layer was extruded from a T-die, and after peeling off the two outer layers, it was taken off at a speed of 5 m/min. The thicknesses of the outer layer, liquid crystal polymer, and outer layer are 15 Atm and 30 Atm, respectively.
It was μ1115 μm. The appearance and surface flatness of the obtained liquid crystalline polymer film are good, but the tensile strength in the MD force direction, TD force direction, and TD force direction are respectively 4100 Kg/am.
", 400 Kg/cm", indicating poor tear resistance.

Comparative Example 2 A T-die single layer film extrusion device was used as a film manufacturing device. Pellets of liquid crystalline polymer (manufactured by Polyplastics (Aji), trade name Vectra A900) were dried in advance at a temperature of 150°C for 8 hours, and then heated to 290°C from an extruder.
I pushed it out. Then, it was picked up at a speed of 5 m/min. The thickness of the liquid crystalline polymer film was 30 μl. The surface of the obtained liquid crystalline polymer film was rough, and the tensile strength in MD force direction TD force direction was 4100, respectively.
The tear resistance was poor at Kg/am" and 120 Kg/cn".

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing one embodiment of the method for producing a liquid crystalline polymer film of the present invention, and FIGS. 2 and 3 each show the state of a multilayer film obtained during the production method of the present invention. FIG. l...Feed block, 2.6...Polymer A channel, 3.5...Liquid crystal polymer channel, 4...
・Polymer B flow path, 7... Single manifold tube, 8...
... Pressure roll, 9 ... 5-layer film, 10 ... Cooling roll, 11.12 ... Liquid crystalline polymer film, 13
．． 14...Polymer A film, t5...
...Polymer B film.

Claims (1)

[Claims] 1. A thermotropic liquid crystalline polymer and a thermoplastic polymer are laminated in a feed block type coextrusion device, with thermoplastic polymer layers on both upper and lower surfaces, and multiple liquid crystalline polymer layers sandwiched between the thermoplastic polymer layers. 1. A method for producing a liquid crystalline polymer film, characterized in that a plurality of thermotropic liquid crystalline polymer films are simultaneously molded by supplying a thermotropic liquid crystalline polymer film in such a manner that a plurality of thermotropic liquid crystalline polymer films are simultaneously molded.