JP2001162666A - Resin guide device of inflation molding apparatus and method for producing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin guide device of an inflation molding apparatus which can obtain a film having a good appearance with reduced wrinkles, thickness nonuniformity, etc., and a method for producing the film. SOLUTION: The guide members 6a, 6b of the resin guide device 3 have frames 7, 9 arranged in parallel at a prescribed interval and permeable guide sheets 8 stuck to the frames 7, 9. The sheets 8 are deformed by the pressure of air, etc., for inflating bubbles B extruded from an inflation molding die 2. When the bubbles B are in contact with a pair of the sheets 8, the sheets 8 wrap up the bubbles B while being pushed outside by the bubbles B, a warped contact surface 9 contacting the bubbles B, with the sheets 8 warped outside from each other, is formed, and the bubbles B are folded flatly in this state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a resin guide device and an inflation molding device in an inflation molding device for guiding a molten resin extruded into a tubular shape from a die for inflation molding and expanded to a pair of take-off rolls. And a method for producing a film for producing a film.

[0002]

2. Description of the Related Art Generally, when a film is produced by inflation molding, molten resin is extruded into a cylindrical shape from an annular slit provided in an inflation molding die, and a gas such as air is blown into the cylindrical resin. The resin is expanded. The expanded cylindrical resin is folded flat by a pair of flat stabilizers disposed so as to be tapered with respect to the resin extrusion direction, and the flat resin is removed by a pair of take-off rolls. And take up with a winder.

In such an inflation molding, as a stabilizer for stabilizing the expanded cylindrical resin and flatly folding the same, a plate made of aluminum, stainless steel or the like, or an appropriate one in a direction perpendicular to the flow direction of the resin. Those that do not easily deform, such as those incorporating a number of guide rolls, have been used.

[0004]

According to the above prior art, general-purpose plastics such as polyethylene (PE) and polypropylene (PP) having a relatively low elastic modulus and a relatively large tensile elongation during cooling and solidification are used as resins. It is very effective when used. That is, when a cylindrical resin is folded flat by a pair of stabilizers, wrinkles and the like may occur in the film due to unevenness in expansion of the resin, a difference in resistance between the resin and the stabilizer, and the like. Is flexible even at room temperature, so that the film obtained by flat folding, taking up and winding up often does not have wrinkles or the like.

On the other hand, in recent years, expectations have been growing for engineering plastic films having high heat resistance, high elastic modulus, and low elongation, and demands for inflation molding capable of obtaining such films relatively inexpensively have increased. ing. However, engineering plastics have a higher elastic modulus and less elongation when solidified by cooling than the general-purpose plastics described above. When the resin is folded, wrinkles, thickness unevenness, and the like are likely to occur, and the appearance of the film may be significantly impaired.

An object of the present invention is to provide a resin guide device in an inflation molding device and a method for producing a film, which make it possible to obtain a film having a good appearance with less wrinkles and uneven thickness.

[0007]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides a resin guide for an inflation molding apparatus which guides a molten resin extruded into a tubular shape from an inflation molding die and expanded to a pair of take-off rolls. An apparatus, comprising: a pair of guide members disposed between an inflation molding die and a pair of take-off rolls, the guide members being configured to fold a cylindrical resin in a flat shape, wherein each of the guide members is curved outwardly. It has a curved contact surface in contact with the cylindrical resin, and the curved contact surface has a shape corresponding to the resin shape when the cylindrical resin is folded flat.

In the present invention, since the tubular resin extruded from the inflation molding die and expanded is folded flat along the curved contact surface having a shape corresponding to the resin shape as described above. The resistance generated by the contact between the cylindrical resin and the guide member is reduced, and the cylindrical resin is smoothly folded and fed to a pair of take-off rolls, thereby reducing wrinkles generated in the resin. I do. Therefore, for example, in the case of performing inflation film formation of a liquid crystal polymer that is harder than a general-purpose polymer, it is possible to obtain a film having a good appearance with less wrinkles, thickness unevenness, and looseness, and to perform stable film formation. Become.

Preferably, the pair of guide members are provided so that the expanded cylindrical resin contacts the curved contact surface before reaching the frost line of the resin, and the expanded cylindrical resin is provided. The height difference between the frost line and the height position at which the frost line starts contacting the curved contact surface is 1/30 to 1/3 of the circumferential length of the cylindrical resin frost line. Thereby, the shape of the cylindrical resin is stabilized, and the resistance generated when the cylindrical resin comes into contact with the guide member is further reduced, and the wrinkles generated in the resin are further reduced.

The pair of guide members are disposed on the pair of take-up rolls so as to be tapered, and have a hardness that can be deformed by the pressure of gas that expands the cylindrical resin. Have each. In this case, when the tubular resin comes into contact with the guide sheet, the guide sheet is pushed outward by the tubular resin and wraps around the resin while being deformed, and in that state, the tubular resin is gradually reduced by the guide sheet. It is folded flat. Thereby, the shape of the curved contact surface can be surely adapted to the resin shape when the cylindrical resin is folded flat, with a relatively simple structure.

In this case, preferably, the pair of guide members has an intersection line formed when the opposing surface of each guide sheet is extended to the pair of take-off rolls, so that each axis of the pair of guide members extends along each axis of the pair of take-up rolls. It is arranged so that it may be located on the surface including. Thereby, wrinkles generated in the resin between the pair of guide members and the pair of take-off rolls can be reduced.

At this time, it is preferable that the sheet opening angle formed by the intersection when the opposing surface of each guide sheet is extended to the pair of take-off rolls is 5 to 60 degrees. This reduces the resistance generated when the cylindrical resin slides on the curved contact surface and the resistance generated when the cylindrical resin is folded by the guide sheet, thereby reducing wrinkles generated in the resin and improving stability. In addition, the appearance of the film is further improved.

[0013] Preferably, the guide sheet is made of a member having air permeability. In this case, when the tubular resin is folded flat by the guide sheet, air enters the guide sheet appropriately from outside the pair of guide members, and the resin is cooled. There is no need to provide a means for forcibly cooling. This prevents, for example, the resin from being excessively cooled in the inflation film formation using a liquid crystalline polymer that is easily cooled and solidified as compared with a general-purpose polymer. And wrinkles and the like generated on the film are further reduced. In addition, when the air ring or the like is not provided, the cost of the inflation molding device can be reduced.

At this time, the member having air permeability is AST
Perm-porometer compliant with MF316
In the air permeability test according to the present invention, when the diameter of the circular test piece used for the test is 38 mm, the air pressure is set to 0.02 kg / g.
The air permeability at a time of cm ² is 200 to 5000 cc / sec.
It is preferably that which becomes c. Thereby, the cylindrical resin is optimally cooled and solidified, and more stable film formation can be performed.

Preferably, the apparatus further includes means for adjusting the tension of the guide sheet, which is provided at one end of the pair of guide members in the vertical direction. Thereby, the expansion unevenness of the cylindrical resin can be reduced, and wrinkles and the like generated on the film are further reduced.

In order to achieve the above object, a method for producing a film according to the present invention comprises extruding a molten resin into a tubular shape from an inflation molding die and blowing a gas into the tubular resin to expand the resin. After that, the tubular resin expanded by the pair of guide members of the resin guide device is flatly folded, the flattened tubular resin is taken up, and the film is formed by further winding up. Is what you do.

As described above, by manufacturing a film using the resin guide device described above,
The resistance when the cylindrical resin comes into contact with the pair of guide members is reduced, and the cylindrical resin is smoothly folded, so that a film having a good appearance with less wrinkles and uneven thickness can be obtained.

As the resin, for example, a liquid crystalline polymer exhibiting optical anisotropy when melted is used. In this case, (A) a liquid crystalline polyester is used as a continuous phase as a liquid crystalline polymer from the viewpoint of moldability and performance of the obtained film.
(B) It is preferable to use a liquid crystal polyester resin composition containing a copolymer having a functional group reactive with the liquid crystal polyester as a dispersed phase. Further, as the liquid crystal polymer, (A) 56.0 to 99.9% by weight of a liquid crystal polyester, and (B) 44.0 to 0.1% by weight of a copolymer having a functional group reactive with the liquid crystal polyester. May be used.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a resin guide device and a method of manufacturing a film according to the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an inflation molding device including a resin guide device according to the present invention, and FIG.
It is a perspective view which shows a resin guide apparatus. In these figures, an inflation molding apparatus 1 includes an inflation molding die 2 and a molten resin (hereinafter referred to as a bubble) which is installed above the inflation molding die 2 and is extruded into a cylindrical shape from the inflation molding die 2 and expanded. B
) And a pair of take-up rolls 4 for taking up the bubble B (tubular film) flattened by the resin guide device 3.
a, 4b and a winding machine 5 for winding the film sent from the take-up rolls 4a, 4b.

The resin guide device 3 has a pair of guide members 6a and 6b which are disposed so as to be tapered upward and fold the bubble B flat. The guide members 6a and 6b are arranged in parallel with each other, and
Frames 7 and 9 that extend substantially parallel to the longitudinal direction (axial direction) of a and 4b, and a guide sheet 8 attached to the frames 7 and 9 respectively.

As the guide sheet 8, an air-permeable material such as a mesh made of metal, resin, or inorganic fiber, a woven fabric such as a glass woven fabric, or a nonwoven fabric is used.
Further, the guide sheet 8 has such a hardness that it is deformed by the pressure of a gas such as air that expands the bubble B, and the curved contact surface 10 ( (See FIG. 3). This allows
The resistance generated by the contact between the bubble B and the guide sheet 8 is reduced, and the wrinkles generated in the bubble B can be suppressed. This will be described later in detail.

The guide sheet 8 also has a function of cooling the bubble B by air entering from outside the guide members 6a and 6b due to the air permeability of the guide sheet 8 itself. Here, in order to cool and solidify the bubble B effectively, A
Perm-Poromet based on STM F316
In the air permeability test by er, when the diameter of the circular test piece used for the test is 38 mm, the air pressure is set to 0.02K.
g / cm ² and air permeability of 200 to 5000 cc /
sec. Thereby, wrinkles generated in the bubble B can be further suppressed.

The guide sheet is not necessarily an air permeable sheet as long as the guide sheet has a hardness such that it is deformed by the pressure of air or the like that expands the bubble B.

The frame 7 located on the side of the take-off rolls 4a, 4b is made of, for example, a metal pipe. During inflation molding, cooling water is introduced into the frame 7,
The upper part of the bubble B is cooled.

The frame 9 located on the side of the inflation molding die 2 is provided with a tension adjusting member 11 including a gear, a stopper, and the like for enabling the guide sheet 8 to be wound and sent out. By changing the length in the vertical direction (the resin extrusion direction), the tension of the guide sheet 8 can be adjusted. By stretching the guide sheet 8 so as to be flat by such a tension adjusting member 11, unevenness of expansion of the bubble B can be reduced, and wrinkles and the like generated in the bubble B can be further reduced.

The pair of guide members 6a, 6a,
6b is arranged so that the expanded bubble B comes into contact with the guide sheet 8 before reaching the frost line (the part where the expansion of the resin ends) F. here,
The height difference d between the height position H at which the expanded bubble B starts to contact the guide sheet 8 and the frost line F of the bubble B is
1/30 to 1 of the circumference of bubble B at frost line F
The value of / 3 is preferable in that the resistance generated at the time of contact can be reduced and the shape of the bubble B can be stabilized.

The pair of guide members 6a, 6b preferably has an intersection line K (see FIG. 1) formed when the facing surface of each guide sheet 8 is extended toward the pair of take-off rolls 4a, 4b. The direction J of the take-up rolls 4a, 4b
It is provided so as to be located on a surface M (a direction perpendicular to the paper surface of FIG. 1) including a and Jb. Thereby, the guide member 6
The wrinkles generated in the bubble B between the a, 6b and the take-up rolls 4a, 4b are reduced. At this time, each guide sheet 8
It is preferable to install a pair of guide members 6a and 6b so that the sheet opening angle θ formed by the intersection when the opposing surface is extended to the take-up rolls 4a and 4b side is 5 to 60 degrees. By doing so, the resistance when the bubble B slides on each guide sheet 8 and the resistance when the bubble B is folded by each guide sheet 8 can be further reduced.

Outside the pair of guide members 6a and 6b,
An air blower 12 for blowing a gas such as air to the guide sheet 8 is provided. This air blower 1
Reference numeral 2 allows air or the like to be blown over the entire width of the guide sheet 8, and the air volume and direction can be adjusted. The air blower is provided with a pair of guide members 6a, 6
A plurality may be arranged outside each of b.

The guide members 6a and 6b are, for example,
It is suspended from an upper support frame (not shown) by an arm (not shown) connected to the frame 7. The air blower 12 is also suspended from the support frame via an arm (not shown).

Next, a method of performing inflation film formation using the inflation molding apparatus 1 including the resin guide device 3 configured as described above will be described.

First, the resin used for the inflation film formation will be described. In the present embodiment, a liquid crystal polyester exhibiting optical anisotropy when melted is used as the resin. The liquid crystal polyester referred to here is a polyester called a thermotropic liquid crystal polymer. Specifically, (1) A compound obtained by reacting an aromatic dicarboxylic acid, an aromatic diol and an aromatic hydroxycarboxylic acid. (2) Those obtained by reacting a combination of different aromatic hydroxycarboxylic acids. (3) A compound obtained by reacting an aromatic dicarboxylic acid with a nucleus-substituted aromatic diol. (4) Those obtained by reacting an aromatic hydroxycarboxylic acid with a polyester such as polyethylene terephthalate. And those which form an anisotropic melt at a temperature of 400 ° C. or lower are preferred. In addition, instead of these aromatic dicarboxylic acids, aromatic diols and aromatic hydroxycarboxylic acids, their ester derivatives may be used.

Examples of the repeating structural unit of the liquid crystal polyester include the following repeating structural units derived from an aromatic dicarboxylic acid, the following repeating structural units derived from an aromatic diol, and the following repeating structural units derived from an aromatic hydroxycarboxylic acid. However, the present invention is not limited to these. Repeating structural unit derived from aromatic dicarboxylic acid:

Embedded image

A repeating structural unit derived from an aromatic diol:

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[0035]

Embedded image

A repeating structural unit derived from an aromatic hydroxycarboxylic acid:

Embedded image Heat resistance, mechanical properties, particularly preferred liquid crystal polyester from the balance of workability,

Embedded image More preferably, the repeating structural unit comprises at least 30
It contains at least mol%. Specifically, the combination of repeating structural units is preferably any one of the following (I) to (VI).

[0037]

Embedded image

[0038]

Embedded image

The method for producing the liquid crystal polyesters (I) to (VI) is described, for example, in JP-B-47-47870, JP-B-63-3888, JP-B-63-3891, and JP-B-56-18016. JP-A-2-515
No. 23, and the like. Of these, a combination of (I), (II) or (IV) is preferable, and a combination of (I) or (II) is more preferable.

In the field where high heat resistance is required in the present invention, the liquid crystal polyester of the component (A) contains 30 to 80 mol% of the following repeating unit (a ′) and 0% of the repeating unit (b ′). -10 mol%, repeating unit (c ') is 1
A liquid crystal polyester having 0 to 25 mol% and a repeating unit (d ') of 10 to 35 mol% is preferably used.

[0041]

Embedded image (In the formula, Ar is a divalent aromatic group.) In the field of the present invention, from the viewpoint of environmental problems, etc., in fields where easiness of disposal such as incineration after use is required, each of the fields listed above is required. Among the preferred combinations in the field to be used, liquid crystal polyesters in particular, which are combinations of elements consisting only of carbon, hydrogen and oxygen, are particularly preferably used.

The component (B) used in the liquid crystal polyester resin composition is a copolymer having a functional group reactive with the liquid crystal polyester. The functional group reactive with the liquid crystal polyester is not particularly limited as long as it has reactivity with the liquid crystal polyester, and specific examples include an oxazolyl group, an epoxy group, and an amino group. Preferably, it is an epoxy group. The epoxy group or the like may be present as a part of another functional group, and such an example includes a glycidyl group.

In the copolymer (B), the method for introducing such a functional group into the copolymer is not particularly limited, and can be carried out by a known method. For example, at the stage of synthesizing the copolymer, it is possible to introduce the monomer having the functional group by copolymerization, or it is also possible to graft copolymerize the monomer having the functional group to the copolymer. It is.

As the monomer having a functional group reactive with the liquid crystal polyester, in particular, as the monomer having a glycidyl group, unsaturated glycidyl carboxylate and / or unsaturated glycidyl ether are preferably used.

Specifically, the unsaturated carboxylic acid glycidyl ester includes, for example, glycidyl acrylate, glycidyl methacrylate, diglycidyl itaconate, triglycidyl butenetricarboxylate,
Glycidyl p-styrenecarboxylate and the like can be mentioned. As unsaturated glycidyl ethers,
For example, vinyl glycidyl ether, allyl glycidyl ether, 2-methylallyl glycidyl ether, methacryl glycidyl ether, styrene-p-glycidyl ether and the like are exemplified.

The unsaturated carboxylic acid glycidyl ester is
Preferably a general formula

Embedded image Wherein R is a hydrocarbon group having an ethylenically unsaturated bond and having 2 to 13 carbon atoms. The unsaturated glycidyl ether is preferably a compound represented by the general formula:

Embedded image (R is a hydrocarbon group having 2 to 18 carbon atoms which has an ethylenically unsaturated bond, X is -CH ₂ -O- or

Embedded image It is. ).

The copolymer (B) having a functional group reactive with the liquid crystal polyester preferably contains an unsaturated carboxylic acid glycidyl ester unit and / or an unsaturated glycidyl ether unit in an amount of 0.1 to 30% by weight. % Of the copolymer. The copolymer (B) having a functional group reactive with the liquid crystal polyester may be a thermoplastic resin or a rubber, or may be a mixture of a thermoplastic resin and a rubber. Good. A rubber having excellent thermal stability and flexibility of a molded product such as a film or sheet obtained by using the liquid crystal polyester resin composition is more preferable.
More preferably, the copolymer (B) having a functional group reactive with the liquid crystal polyester is a copolymer having a heat of fusion of crystal of less than 3 J / g.

The copolymer (B) preferably has a Mooney viscosity of 3 to 70, more preferably 3 to 30, and particularly preferably 4 to 25. The Mooney viscosity mentioned here is 10 according to JIS K6300.
A value measured using a large rotor at 0 ° C. Outside these ranges, the thermal stability and flexibility of the composition may be undesirably reduced.

The rubber mentioned here corresponds to a polymer substance having rubber elasticity at room temperature according to a new edition of Polymer Dictionary (edited by the Society of Polymer Science, published in 1988, Asakura Shoten).
Specific examples thereof include natural rubber, butadiene polymer, butadiene-styrene copolymer (including random copolymer, block copolymer (including SEBS rubber or SBS rubber, etc.), and graft copolymer), or The hydrogenated product, isoprene polymer, chlorobutadiene polymer, butadiene-acrylonitrile copolymer, isobutylene polymer, isobutylene-butadiene copolymer rubber,
Isobutylene-isoprene copolymer, acrylate-ethylene copolymer rubber, ethylene-propylene copolymer rubber, ethylene-butene copolymer rubber, ethylene-propylene-styrene copolymer rubber, styrene-isoprene copolymer Rubber, styrene-butylene copolymer, styrene-ethylene-propylene copolymer rubber, perfluoro rubber, fluoro rubber, chloroprene rubber, butyl rubber, silicone rubber, ethylene-propylene-non-conjugated diene copolymer rubber, thiol rubber, polysulfide Examples include rubber, polyurethane rubber, polyether rubber (for example, polypropylene oxide, etc.), epichlorohydrin rubber, polyester elastomer, polyamide elastomer, and the like. Among them, an acrylate-ethylene copolymer is preferably used, and a (meth) acrylate-ethylene copolymer rubber is more preferred. These rubber-like substances may be produced by any production method (eg, emulsion polymerization method, solution polymerization method, etc.) and any catalyst (eg, peroxide, trialkylaluminum, lithium halide, nickel-based catalyst, etc.). .

The rubber as the copolymer (B) is a rubber having a functional group reactive with the liquid crystal polyester in the above rubber. In such a rubber, a method for introducing a functional group reactive with the liquid crystal polyester into the rubber is not particularly limited, and can be performed by a known method. For example, it is possible to introduce the monomer having the functional group by copolymerization at the stage of synthesizing the rubber, or it is also possible to graft copolymerize the monomer having the functional group to the rubber.

As a specific example of the copolymer (B) having a functional group reactive with the liquid crystal polyester, rubbers having an epoxy group include (meth) acrylate-ethylene- (unsaturated glycidyl carboxylate) And / or unsaturated glycidyl ether) copolymer rubber.

Here, the (meth) acrylic acid ester is an ester obtained from acrylic acid or methacrylic acid and an alcohol. As the alcohol, an alcohol having 1 to 8 carbon atoms is preferable. Specific examples of (meth) acrylates include methyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, tert-butyl acrylate, t
Examples thereof include tert-butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. As the (meth) acrylic acid ester, one kind thereof may be used alone, or two or more kinds may be used in combination.

Preferably, the (meth) acrylate unit is 40% by weight or more and less than 97% by weight, more preferably 45-70% by weight, and the ethylene unit is 3% by weight or more and 50% by weight.
%, More preferably 10 to 49% by weight, and 0.1 to 30% by weight, more preferably 0.5 to 20% by weight, of unsaturated carboxylic acid glycidyl ether units and / or unsaturated glycidyl ether units. If the ratio is outside the above range, the resulting molded product such as a film or sheet may have insufficient thermal stability and mechanical properties, which is not preferable.

The copolymer rubber can be produced by a usual method, for example, bulk polymerization, emulsion polymerization, solution polymerization or the like using a free radical initiator. Typical polymerization methods are described in JP-B-46-45085 and JP-B-6-45085.
No. 1-127709, pressure of 500 k in the presence of a polymerization initiator generating free radicals
g / cm ² or more and a temperature of 40 to 300 ° C.

Other rubbers usable for the copolymer (B) include acrylic rubber having a functional group reactive with liquid crystal polyester and vinyl aromatic having a functional group reactive with liquid crystal polyester. A hydrocarbon compound-conjugated diene compound block copolymer rubber can also be exemplified.

The acrylic rubber mentioned here is preferably represented by the general formula (1)

Embedded image (In the formula, R ¹ represents an alkyl group having 1 to 18 carbon atoms or a cyanoalkyl group.), A general formula (2)

Embedded image (Wherein, R ² is an alkylene group having 1 to 12 carbon atoms, R ³
Represents an alkyl group having 1 to 12 carbon atoms. ) And general formula (3)

Embedded image (Wherein R ⁴ is a hydrogen atom or a methyl group, R ⁵ is an alkylene group having 3 to 30 carbon atoms, and R ⁶ is a 1 to 20 carbon atom.
Wherein n represents an integer of 1 to 20; )) At least one monomer selected from the compounds represented by the formula (1).

Specific examples of the alkyl acrylate represented by the above general formula (1) include, for example, methyl acrylate, ethyl acrylate, propyl acrylate,
Examples thereof include butyl acrylate, pentyl acrylate, hexyl acrylate, actyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, dodecyl acrylate, and cyanoethyl acrylate.

Examples of the alkoxyalkyl acrylate represented by the general formula (2) include methoxyethyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, and ethoxypropyl acrylate. One or more of these can be used as the main component of the acrylic rubber.

As a constituent component of the acrylic rubber, an unsaturated monomer copolymerizable with at least one monomer selected from the compounds represented by the above general formulas (1) to (3), if necessary. Can be used. Examples of such unsaturated monomers include styrene, α-methylstyrene,
Acrylonitrile, halogenated styrene, methacrylonitrile, acrylamide, methacrylamide, vinylnaphthalene, N-methylolacrylamide, vinyl acetate, vinyl chloride, vinylidene chloride, benzyl acrylate, methacrylic acid, itaconic acid, fumaric acid, maleic acid, and the like. .

The preferred component ratio of the acrylic rubber having a functional group reactive with the liquid crystal polyester is at least one monomer 40 selected from the compounds represented by the above general formulas (1) to (3). 0.0 to 99.9% by weight, unsaturated glycidyl carboxylate and / or unsaturated glycidyl ether 0.1 to 30.0% by weight, selected from the compounds represented by the above general formulas (1) to (3). Unsaturated monomer copolymerizable with at least one monomer
３30.0% by weight. When the constituent ratio of the acrylic rubber is within the above range, heat resistance and impact resistance of the composition,
The molding processability is good and preferable.

The method for producing the acrylic rubber is not particularly limited. For example, JP-A-59-113010, JP-A-62-64809, and JP-A-3-160008
Or a well-known polymerization method described in WO95 / 04764 or the like, and can be produced by emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization in the presence of a radical initiator. .

The vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer rubber having a functional group reactive with the liquid crystal polyester is preferably (a)
Epoxidation of a rubber obtained by epoxidizing a block copolymer consisting of a sequence mainly composed of a vinyl aromatic hydrocarbon compound and (b) a sequence mainly composed of a conjugated diene compound, or epoxidation of a hydrogenated product of the block copolymer This is the rubber obtained.

The vinyl aromatic hydrocarbon compound-conjugated diene compound block copolymer or its hydrogenated product can be produced by a well-known method.
798 and JP-A-59-133203.

As the aromatic hydrocarbon compound, for example,
Styrene, vinyltoluene, divinylbenzene, α-methylstyrene, p-methylstyrene, vinylnaphthalene and the like can be mentioned, among which styrene is preferable.
Examples of the conjugated diene compound include butadiene, isoprene, pyrrylene, 1,3-pentadiene, 3-butyl-1,3-octadiene and the like, butadiene or isoprene is preferred.

As the rubber used as the copolymer (B),
Preferably, (meth) acrylate-ethylene-
(Unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer rubber is used. The rubber used as the copolymer (B) may be vulcanized as necessary and used as a vulcanized rubber. The vulcanization of the (meth) acrylic acid ester-ethylene- (unsaturated carboxylic acid glycidyl ester and / or unsaturated glycidyl ether) copolymer rubber is performed by multifunctional organic acids, polyfunctional amine compounds, imidazole compounds, etc. However, the present invention is not limited to these.

As a specific example of the copolymer (B) having a functional group reactive with the liquid crystal polyester, a thermoplastic resin having an epoxy group includes (a) an ethylene unit of 50 to 99% by weight; b) 0.1 to 30% by weight, preferably 0.5 to 20% by weight of unsaturated carboxylic acid glycidyl ester units and / or unsaturated glycidyl ether units.
% By weight, and (c) an epoxy group-containing ethylene copolymer having an ethylenically unsaturated ester compound unit of 0 to 50% by weight.

Examples of the ethylenically unsaturated ester compound (c) include vinyl carboxylate such as vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate and butyl methacrylate. Esters, α, β-unsaturated carboxylic acid alkyl esters, and the like. Particularly, vinyl acetate, methyl acrylate and ethyl acrylate are preferred.

Specific examples of the epoxy group-containing ethylene copolymer include, for example, a copolymer composed of an ethylene unit and a glycidyl methacrylate unit, a copolymer composed of an ethylene unit and a glycidyl methacrylate unit, and a methyl acrylate unit. Copolymers composed of glycidyl methacrylate units and ethyl acrylate units, and copolymers composed of ethylene units, glycidyl methacrylate units and vinyl acetate units are exemplified.

The melt index of the epoxy group-containing ethylene copolymer (hereinafter, may be referred to as MFR. JI.
SK6760, 190 ° C, 2.16 kg load) is preferably 0.5 to 100 g / 10 min, more preferably 2 to 100 g / 10 min.
５０50 g / 10 min. The melt index may be outside this range, but the melt index is 100 g
If it exceeds / 10 minutes, it is not preferable in view of the mechanical properties of the composition, and if it is less than 0.5 g / 10 minutes, the compatibility with the liquid crystal polyester of the component (A) is inferior.

[0070] Also, the epoxy group-containing ethylene copolymer is preferably in the range stiffness modulus of 10~1300kg / cm ^2, further preferably from 20~1100kg / cm ^2. If the flexural rigidity is out of this range, the molding processability and mechanical properties of the composition may be insufficient, which is not preferable.

The epoxy group-containing ethylene copolymer is usually prepared by reacting an unsaturated epoxy compound and ethylene in the presence of a radical generator at 500 to 4000 atm and 100 to 300 ° C. in the presence or absence of a suitable solvent or chain transfer agent. It is produced by a high-pressure radical polymerization method in which copolymerization is carried out in the presence. It can also be produced by a method in which an unsaturated epoxy compound and a radical generator are mixed with polyethylene and melt-grafted and copolymerized in an extruder.

The above-mentioned liquid crystal polyester resin composition comprises:
A resin composition comprising (A) a liquid crystal polyester as a continuous phase and (B) a copolymer having a functional group reactive with the liquid crystal polyester as a dispersed phase. If the liquid crystal polyester is not a continuous phase, the gas barrier properties, heat resistance, etc. of a molded article such as a film or sheet made of the liquid crystal polyester resin composition may be significantly reduced, which is not preferable.

The details of the mechanism of such a resin composition of a copolymer having a functional group and a liquid crystal polyester are unknown, but the resin composition between the component (A) and the component (B) of the composition is not clear. It is considered that a reaction occurs, and the component (A) forms a continuous phase, and the component (B) is finely dispersed, thereby improving the moldability of the composition.

One embodiment of the above liquid crystal polyester resin composition comprises (A) 56.0 to 99.9 liquid crystal polyester.
44% by weight, preferably 65.0 to 99.9% by weight, more preferably 70 to 98% by weight, and (B) a copolymer having a functional group reactive with the liquid crystal polyester.
The resin composition contains 0 to 0.1% by weight, preferably 35.0 to 0.1% by weight, and more preferably 30 to 2% by weight. If the content of the component (A) is less than 56.0% by weight, the gas barrier properties and heat resistance of a molded article such as a film or sheet obtained from the composition may be undesirably reduced. On the other hand, if the component (A) exceeds 99.9% by weight, the molding processability of the composition may be reduced, and the composition is expensive, which is not preferable.

As a method for producing such a liquid crystal polyester resin composition, a known method can be used. For example, there is a method in which each component is mixed in a solution state and the solvent is evaporated or precipitated in the solvent. From an industrial point of view, a method of kneading each component of the above composition in a molten state is preferred. For the melt kneading, kneading apparatuses such as a single-screw or twin-screw extruder and various kneaders which are generally used can be used. In particular, a biaxial high kneader is preferred. During melt-kneading, the cylinder set temperature of the kneading device is 20
The temperature is preferably in the range of 0 to 360 ° C, more preferably 23
0-350 ° C.

At the time of kneading, the respective components may be previously mixed uniformly using a device such as a tumbler or a Henschel mixer. If necessary, the mixing may be omitted, and the components may be separately supplied to the kneading device. Methods can also be used.

Next, a specific method of forming a film by inflation film formation of the above liquid crystal polyester will be described.

First, a liquid crystal polyester in a molten state is fed into an inflation molding die 2 from an extruder (not shown), and is extruded cylindrically upward from an annular slit of the inflation molding die 2. Then, air is blown into the cylindrical resin (bubble) B via an air introduction pipe (not shown) formed in the inflation molding die 2,
Inflate bubble B. The bubble B is guided to the pair of take-off rolls 4a and 4b while being folded flat by the pair of guide members 6a and 6b.

At this time, the bubble B is moved by the two guide members 6a,
Before contacting the guide sheet 8 of 6b, as shown in FIG. 3A, the bubble B expands while being maintained in a cylindrical shape. When the bubble B comes into contact with the two guide sheets 8 and starts to slide on the surface of the guide sheet 8, the guide sheet 8 is pushed outward by the internal pressure due to the expansion of the bubble B. This is combined with the wind pressure of the air blown from the air blower 12 toward the guide sheet 8, so that the guide sheet 8 wraps the bubble B as shown in FIG.
Then, in this state, the bubble B is gradually folded flat. In other words, the pair of guide sheets 8 are curved outwardly in contact with the bubble B in a state of being curved outward.
(Described above) is forcibly formed. This allows
The curved contact surface 10 necessarily has a shape corresponding to the bubble shape when the bubble B is folded flat. Therefore, the bubble B and the guide members 6a, 6b
The resistance generated by the contact with the bubble B is reduced, the bubble B is smoothly folded, and the wrinkle generated in the bubble B is reduced.

When the bubble B is folded in this way, natural air and air blown from the air blower 12 enter the air-permeable guide sheet 8, so that the bubble B is gradually cooled while being folded. You. Here, even if a slight wrinkle occurs in the bubble B due to the resistance when the bubble B comes into contact with the guide sheet 8,
Since the state of having plasticity in the resin becomes longer,
Before the bubble B is solidified at the upper part of each guide sheet 8,
The wrinkles of the bubble B are almost completely removed.

Then, as shown in FIG. 3C, the bubble B becomes substantially flat in a solidified state, and is sent to the pair of take-off rolls 4a and 4b. Thereafter, the flattened bubble B (cylindrical film) is transferred to a pair of take-off rolls 4.
a and 4b, and further wound by a winder 5.

As described above, in the present embodiment, a pair of guide members 6a and 6b is provided with an air-permeable guide sheet 8, and the guide sheet 8 is provided with a bubble when the bubble B is folded flat. Since the curved contact surface 9 having the curvature corresponding to the shape is formed, the bubble B can be folded while being cooled smoothly and effectively, thereby reducing wrinkles, thickness unevenness, looseness, and the like. A film having a good appearance is stably obtained.

At this time, since a guide sheet 8 which can be deformed by the pressure of air or the like for expanding the bubble B is used, the curved contact surface 9 can be easily formed with a relatively simple structure.

Although the preferred embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the guide members 8a and 6b are provided with the guide sheets 8 that can be deformed by the internal pressure due to the expansion of the bubbles B, and the bubbles B contact the guide sheets 8 so that the bubbles B are folded flat. Curved contact surface 9 having a curvature corresponding to the bubble shape
However, the pair of guide members is not particularly limited to such a structure. For example, a pair of guide members may be formed of a plate of aluminum, stainless steel, or the like, and a curved contact surface may be formed in advance by bending the plate to match the bubble shape when the bubble B is folded flat. .

The resin guide device 3 of the above embodiment
Is located above the inflation molding die 2, but the present invention provides a resin in which a pair of guide members 6a and 6b are disposed below the inflation molding die 2 so as to taper downward. It is also applicable to a guide device.

In the above embodiment, a liquid crystal polymer which exhibits optical anisotropy when melted is used as the resin. However, the present invention is not limited to this, and general-purpose plastics such as polyethylene and polypropylene may be used. it can.

[0087]

EXAMPLES The present invention will be described below with reference to examples, but these are merely examples, and the present invention is not limited to these examples. (1) Liquid crystal polyester of component (A) (i) 8.3 kg (60 mol) of p-acetoxybenzoic acid, 2.49 kg (15 mol) of terephthalic acid, 0.83 kg (5 mol) of isophthalic acid and 4,4 ′ 5.45 kg (20.2 mol) of diacetoxydiphenyl was charged into a polymerization tank having a comb-shaped stirring blade, the temperature was increased while stirring under a nitrogen gas atmosphere, and polymerization was performed at 330 ° C. for 1 hour. During this time, polymerization was carried out under strong stirring while liquefying and collecting and removing acetic acid gas produced as a by-product in a cooling tube. Thereafter, the system was gradually cooled, and the polymer obtained at 200 ° C. was taken out of the system. The obtained polymer was pulverized with a hammer mill manufactured by Hosokawa Micron Co., Ltd. to obtain particles of 2.5 mm or less. This is further reduced to 28 in a nitrogen atmosphere in a rotary kiln.
By treating at 0 ° C. for 3 hours, the flow start temperature becomes 3
A particulate wholly aromatic polyester at 24 ° C. was obtained.

Here, the flow start temperature is defined as 4 ° C./cm using a Shimadzu Flow Tester Model CFT-500 manufactured by Shimadzu Corporation.
Resin heated and melted at a heating rate of
It is a temperature at which the melt viscosity shows 48,000 poise when extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm under f / cm ² .

Hereinafter, this liquid crystal polyester is abbreviated as A-1. This polymer showed optical anisotropy at 340 ° C. or higher under pressure. The repeating structural units of the liquid crystal polyester A-1 are as follows.

[0090]

Embedded image

(Ii) p-hydroxybenzoic acid 16.6k
g (12.1 mol), 8.4 kg (4.5 mol) of 6-hydroxy-2-naphthoic acid and 18.6 kg of acetic anhydride
(18.2 mol) was charged into a polymerization vessel equipped with a comb-shaped stirring blade, and the temperature was increased while stirring under a nitrogen gas atmosphere.
For 1 hour, and further at 320 ° C. for 1 hour under a reduced pressure of 2.0 torr. During this time, acetic acid produced as a by-product was continuously distilled out of the system. Thereafter, the system is gradually cooled and
The polymer obtained at 80 ° C. was taken out of the system.

The obtained polymer is pulverized in the same manner as in the above (i) and then treated in a rotary kiln under a nitrogen gas atmosphere at 240 ° C. for 5 hours to obtain a particulate total aroma having a flow start temperature of 270 ° C. A group polyester was obtained.

Hereinafter, this liquid crystal polyester is abbreviated as A-2. This polymer showed optical anisotropy at 280 ° C. or more under pressure. The repeating structural units of the liquid crystal polyester A-2 are as follows.

[0094]

Embedded image

(2) Rubber of Component (B) Methyl acrylate / ethylene / glycidyl methacrylate = 59.0 / 38.7 / 2 according to the method described in Example 5 of JP-A-61-127709. .3 (weight ratio), a rubber having a Mooney viscosity of 15 was obtained. Here, the Mooney viscosity is a value measured using a large rotor at 100 ° C. according to JIS K6300. Hereinafter, this rubber is abbreviated as B-1.

(3) Measurement of air permeability 0.2 kg of a circular test piece having a diameter of 38 mm
/ Cm ² of air was applied, and how many cc of air passed per second was measured. This air permeability test is AST
Perm-Poromete compliant with MF316
r.

(4) Reference Example 1 A-1 / B-1 = 85 parts by weight / 15 parts by weight.
Using TEX-30 twin screw extruder manufactured by Nippon Steel Corporation, cylinder set temperature 335 ° C, screw rotation speed 250r
The composition was obtained by melt-kneading at pm. The composition pellets exhibited optical anisotropy at 330 ° C. or higher under pressure. Hereinafter, this pellet may be abbreviated as P-1.

(5) Reference Example 2 A-2 / B-1 = 85 parts by weight / 15 parts by weight.
Using a TEX-30 twin screw extruder manufactured by Nippon Steel Corporation, cylinder set temperature 305 ° C, screw rotation speed 200r
The composition was obtained by melt-kneading at pm. The composition pellets exhibited optical anisotropy at 295 ° C. or higher under pressure. Hereinafter, this pellet may be abbreviated as P-2.

(6) Example 1 A liquid crystal polymer (P-1) was sufficiently supplied to a resin supply port of a 60 mmΦ screw extruder, and the resin was discharged to an inflation molding die at a rotation speed of 120 rpm. The diameter of the die for inflation molding is 100 mm, and the gap of the lip (resin flow path) of the die is 1 mm. The extruder was set at an average temperature of 340 ° C., and the inflation molding die was set at 345 ° C. to form a film. The structure of the pair of guide members of the resin guide device is as follows.

First, one set (two pieces) of 1 m × 1 m square frames made of a stainless steel bar having a cross section of 10 mm × 10 mm was prepared, and these were tapered in the resin extrusion direction. Are arranged so that one side of the pair extends parallel to the longitudinal direction of the take-up roll. At this time, the upper end of the pair of guide members (the end on the take-up roll side)
Is 70 mm. Also, the intersection line formed when the opposing surface of each frame is extended toward the take-up roll is located on the plane including the axis of each take-up roll, and the sheet opening angle created by the intersection is about 20 degrees. ing. Also, outside the lower end of each square frame,
A stainless steel square member (tension adjusting member) with a stopper for winding and sending out the following guide sheet is provided.

Then, on the inside (opposite side) of each square frame, a glass woven cloth (G &
J Company Sputter Sheet Gold Alpha) was attached. Thereafter, the woven fabric was stretched so as to be completely flat, and the woven fabric was sent out until the expanded cylindrical resin film was stabilized. The sending amount was 4 cm. The length of the glass woven fabric in the left-right direction is 0.95 m, and both ends of the glass woven fabric are not fixed to the square frame.

In such a configuration, the woven fabric itself deforms so as to wrap the expanded cylindrical resin while deforming the expanded cylindrical resin film so that the central portion becomes convex outward. It was folded flat in that state.

The resin film was taken under the conditions of a blow ratio of 3.0 and a drawdown ratio of 30.5. At this time, the resin (bubble) expanded into a cylindrical shape is in contact with the guide sheet from about 10 cm below the frost line to the upper part, and almost no swing of the bubble in the left-right direction is recognized, and the wound film is taken up. The end faces were almost aligned. The width of the film obtained by folding flat and stacking two sheets is 470 mm, and the thickness of the film obtained by cutting off and removing 30 mm at both ends is 11 ± 1 μm.
However, almost no wrinkles or loosening were observed.

(7) Example 2 Example 1 was repeated except that stainless steel plain weave # 100 mesh was used as a guide sheet for a pair of guide members.
The same as above.

The resin film was taken under the conditions of a blow ratio of 2.4 and a drawdown ratio of 11.9. At this time, the expanded cylindrical resin was in contact with the guide sheet from about 10 cm below the frost line to the top. The width of the film obtained by folding flat and stacking two sheets is 38.
The thickness of the obtained film was 35 ± 5 μm, and almost no wrinkles or looseness were observed.

(8) Example 3 A resin (P-
2) was sufficiently supplied, and the resin was discharged at a rotation speed of 100 rpm. The extruder was set at an average temperature of 340 ° C., and the inflation molding die was set at 345 ° C. to form a film. As a guide sheet for a pair of guide members, p-aramid woven fabric (Twaron plain woven fabric manufactured by Nippon Aramid Co., Ltd., basis weight: 450 g / m ² , air permeability: 0.02
1500 cc / sec at a pressure of Kg / cm ² was used. Other than that was the same as Example 1.

The resin film was taken under the conditions of a blow ratio of 2.6 and a drawdown ratio of 15.4. At this time, the expanded cylindrical resin was in contact with the guide sheet from about 10 cm below the frost line to the top. The width of the film obtained by folding flat and stacking two sheets is 41
The thickness of the obtained film was 25 ± 3 μm, and almost no wrinkles or looseness was observed.

(9) Example 4 Resin (P-) was supplied to the resin supply port of a 60 mmΦ screw extruder.
2) was sufficiently supplied, and the resin was discharged at a rotation speed of 100 rpm. The extruder was set at an average temperature of 295 ° C., and the inflation molding die was set at a temperature of 300 ° C. to form a film. Further, a Teflon sheet having a thickness of 100 μm was used as a guide sheet for the pair of guide members. Other than that was the same as Example 1.

The resin film was taken under the conditions of a blow ratio of 2.5 and a drawdown ratio of 20.0. At this time, the expanded cylindrical resin was in contact with the guide sheet from about 10 cm below the frost line to the top. The width of the film obtained by folding flat and stacking two sheets is 39.
The thickness of the film obtained by cutting off and removing 30 mm at both ends was 20 ± 3 μm, and almost no wrinkles or looseness were observed.

(10) Comparative Example 1 As a guide member, a 1 m × 1 m aluminum plate (thickness: 3 mm) was attached to a square frame, and a glass woven cloth (a sputtered sheet manufactured by G & J) was placed on the square frame (the area where the resin contacts). Gold Alpha). Otherwise, film formation was performed in the same manner as in Example 1 to obtain a film.

During the film formation, the bubbles oscillated left and right parallel to the surface of the aluminum plate, and the end faces of the wound film were not aligned. In the obtained film, many wrinkles and looseness were observed on the entire surface, and the thickness of the film obtained by folding and peeling off the film obtained by stacking two sheets was 11 ± 3 μm, and uneven thickness was observed. Was.

(11) Comparative Example 2 As a guide member, a 1 m × 1 m aluminum plate (thickness: 3 mm) was attached to a square frame, and a p-aramid woven cloth (Nihon Aramid Co., Ltd.) Twaron plain woven fabric, basis weight: 450 g / m ² ). Other than that, film formation was performed in the same manner as in Example 3 to obtain a film.

During the film formation, the bubbles oscillated left and right parallel to the surface of the aluminum plate, and the end faces of the wound film were not aligned. Also, in the obtained film, many wrinkles and looseness were observed on the entire surface, and the thickness of the film obtained by folding and peeling the film obtained by stacking two sheets was 25 ± 7 μm, and uneven thickness was observed. Was.

[0114]

According to the present invention, a pair of guide members are provided.
Since a curved contact surface having a shape corresponding to the shape of the resin when the cylindrical resin is folded flat is provided, the resistance generated by the contact between the cylindrical resin and the guide member is reduced, and wrinkles generated on the resin film are reduced. And uneven thickness are reduced. This makes it possible to stably produce a film having a good appearance.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an inflation molding device including a resin guide device according to the present invention.

FIG. 2 is a perspective view of a resin guide device according to the present invention.

FIG. 3 is a diagram showing a state in which a bubble is folded flat by a pair of guide members.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inflation molding device, 2 ... Inflation molding die, 3 ... Resin guide device, 4a, 4b ... Take-off roll, 6a, 6b ... Guide member, 8 ... Guide sheet (member having air permeability), 10 ... Curved contact surface , 11: tension adjusting member, B: bubble (tubular resin).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Motonobu Furuta 6th Kitahara, Tsukuba, Ibaraki Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor Akio Morii 2220 Fukutomishinmachi, Ashikaga, Tochigi 72) Inventor Noriyuki Oshima 2220 Fukutomishinmachi, Ashikaga City, Tochigi Prefecture F-term in Thermo Co., Ltd.

Claims (12)

[Claims] 1. A resin guide device in an inflation molding device for guiding a molten resin which is extruded into a tubular shape from a die for inflation molding and expanded to a pair of take-off rolls, wherein the inflation molding die and the pair of A pair of guide members that are disposed between the take-up roll and fold the tubular resin flat, wherein each of the guide members is a curved contact surface that contacts the tubular resin in a state in which the guide members are curved outward. And a curved contact surface having a shape corresponding to the shape of the resin when the cylindrical resin is folded flat. 2. The pair of guide members are provided so that the expanded tubular resin contacts the curved contact surface before reaching the frost line of the resin, and the expanded tubular resin is provided. The height difference between the frost line and the height position at which the cylindrical resin starts to contact the curved contact surface is 1/30 to 1/30 of the circumferential length of the cylindrical resin at the frost line.
The resin guide device according to claim 1, wherein the ratio is 1/3. 3. The pair of guide members are disposed so as to be tapered on the pair of take-off rolls, and have a hardness such that the guide members can be deformed by the pressure of a gas that expands the cylindrical resin. The resin guide device according to claim 1, further comprising a guide sheet. 4. The pair of guide members, wherein a line of intersection formed when an opposing surface of each guide sheet is extended toward the pair of take-off rolls is formed by a line of intersection of each axis of the pair of take-up rolls. The resin guide device according to claim 3, wherein the resin guide device is disposed so as to be located on a plane including the resin guide. 5. The resin according to claim 4, wherein the sheet opening angle formed by the intersection when the facing surface of each of the guide sheets is extended to the pair of take-off rolls is 5 to 60 degrees. Guide device. 6. The resin guide device according to claim 3, wherein the guide sheet is made of a member having air permeability. 7. The air-permeable member is made of an ASTM.
In an air permeability test using a Perm-Porometer based on F316, when the diameter of a circular test piece used for the test is 38 mm, the air pressure is set to 0.02 kg / cm.
7. The resin guide device according to claim 6, wherein the air permeability when set to ² is 200 to 5000 cc / sec. 8. The apparatus according to claim 3, further comprising means for adjusting the tension of the guide sheet, provided at one end of the pair of guide members in a vertical direction. Resin guide device. 9. The resin according to any one of claims 1 to 8, wherein the molten resin is extruded into a tubular shape from an inflation molding die, and a gas is blown into the tubular resin to expand the resin. A film is produced by flatly folding the expanded tubular resin by the pair of guide members of the guide device, taking up the flattened tubular resin, and further winding the film. Production method. 10. The method for producing a film according to claim 9, wherein a liquid crystalline polymer exhibiting optical anisotropy when melted is used as said resin. 11. A liquid crystal polyester resin composition comprising (A) a liquid crystal polyester as a continuous phase and (B) a copolymer having a functional group reactive with the liquid crystal polyester as a dispersed phase. The method for producing a film according to claim 10, which is used. 12. A copolymer having (A) 56.0 to 99.9% by weight of a liquid crystal polyester and (B) a copolymer having a functional group reactive with the liquid crystal polyester as a liquid crystal polymer. 11. The method for producing a film according to claim 10, wherein a composition obtained by melt-kneading 0.1% by weight is used.