JPH11170283A - Method and apparatus for making film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a film making speed in solution film making and to obtain a film or a sheet-like molding which is excellent in surface properties and flatness. SOLUTION: In the method in which an organic polymer solution is cast on a support to form a film or a sheet-like molding, a mixed solvent of a solvent which is not compatible with the polymer but compatible with the solvent and a solvent which is compatible with both the polymer and the solvent is placed between the support and an organic polymer solution membrane to be cast.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a film forming method and a film forming apparatus, and more particularly to a film forming method and a film forming apparatus used for forming a solution of polycarbonate, aromatic polyamide, aromatic polyimide, or the like.

[0002]

2. Description of the Related Art For example, a method using an air knife as a means for bringing a molten film or a solution film extruded from a T-die into close contact with a support is disclosed in JP-A-61-121923 and JP-A-59-68681. A method utilizing an electrostatic field is known from Japanese Patent Publication No. 50-8743, Japanese Patent Application Laid-Open No. 59-138416, and the like. Also,
A method of disposing a slit-shaped suction nozzle between a molten film or solution film and a support is known from Japanese Patent Application Laid-Open No. 2-52721.

[0003] However, the method using an air knife is suitable for forming a thick or extremely viscous film, but a high dynamic pressure is required to increase the degree of adhesion, and the turbulence of the wind pressure Causes unstable film formation.
This tendency is more affected by a solution film having a lower viscosity. In addition, the method using an electrostatic field is not preferable because an organic solvent is often used in the solution casting, and there is a risk of ignition, and it is applied in principle unless the object to be cast is chargeable. Is difficult. Further, even with the method using a slit-shaped suction nozzle, a large air flow is required to obtain a high dynamic pressure or static pressure as in the case of the air knife method, and the pressure increases as the suction increases. The film formation is not stable due to the influence.

The above problems in these means are remarkable particularly in a thin film which is easily affected by an external force. When the speed is increased, air is trapped between the molten film or the solution film and the cast support, and the film is formed. There was a problem that it became impossible.

On the other hand, as a method for forming a molten film, a method in which a liquid film is formed on a drum and cast is disclosed in Japanese Patent Laid-Open No. 64-53.
820, JP-A-1-320130, JP-A-2-219610 and the like. However, the liquid film is essentially a foreign substance with respect to the molten polyester or polyamide, and the high-temperature molten film is cooled non-uniformly and rapidly, or the liquid film-forming substance is vaporized. Due to the deformation and roughness caused by the film,
In particular, it cannot be applied to applications that require a thin film as described below and require a precisely controlled surface.

[0006]

The method using an air knife, a suction nozzle, an electrostatic field, or the like is intended to stabilize a cast by bringing an extruded molten or solution film into close contact with a support. Is limited, but there is a need to speed up casting to further improve productivity.

On the other hand, recording media such as magnetic tapes have been reduced in size, and demands for longer recording times have led to a demand for thinner recording media. There is a demand for a controlled surface property or flatness. Conventionally, polyethylene terephthalate has been used for such applications, but materials such as aromatic polyamides or aromatic polyimides having higher rigidity have been studied. However, aromatic polyamides and aromatic polyimides having high rigidity can be obtained only by solution film formation, and it is difficult to form a thin film at a high speed by the above-described means.

[0008] In addition, polycarbonate and polymethacrylic acid resins, which have high needs for use in optical members, have similar problems.

Further, when a step of hot-treating a solution film such as a dry method or a dry-wet method as a solution film-forming method is included, a streak pattern generated due to a die or other scratches during casting is effectively eliminated. However, there is a concern that if the drying proceeds excessively, the higher-order structure may be disturbed or the stretchability may be reduced, thereby lowering the productivity and the physical properties.

An object of the present invention is to solve the above problems by producing a film or a sheet-like molded product from an organic polymer solution at a higher speed than a conventional casting stabilizing means. It is also possible to form a stable film even if it is thin, and the surface properties and flatness of the obtained film or sheet-like molded body are good, and the physical properties and productivity can be improved. An object of the present invention is to provide a film forming method and an apparatus for manufacturing the film or sheet-like molded body.

[0011]

Means for Solving the Problems In order to solve the above problems, a film forming method of the present invention is directed to a method for obtaining a film or sheet-like molded article by casting an organic polymer solution on a support. Between the support and the cast organic polymer solution membrane: not compatible with the organic polymer but compatible with the solvent mainly used in the solution. Solvent having: a method characterized by casting by interposing a mixed solvent comprising a solvent having compatibility with the organic polymer and a solvent mainly used in the solution.

Further, the film forming apparatus according to the present invention provides a means for extruding an organic polymer solution, a support for supporting the extruded organic polymer solution, and forming by removing a solvent in the solution. Means for obtaining a film or sheet-like molded body provided with a means, wherein between the extruded organic polymer solution and the support: A solvent compatible with the solvent mainly used in the solution, means for interposing a mixed solvent comprising the organic polymer and a solvent compatible with the solvent mainly used in the solution; It is characterized by having.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The organic polymer used in the present invention is not particularly limited as long as it can be dissolved in one or more appropriate organic or inorganic solvents and the solution can be used for film formation. There is no. Examples of such organic polymer include polycarbonate, polyurethane, polyvinyl alcohol-based resin, polyacrylonitrile, polyamide resin such as aromatic polyamide, aromatic polyimide, polyester amide, polyamide imide, polyacrylic resin, polymethacrylic acid. Resins, polyester resins, cellulosic polymers, silicone resins, fluororesins, and the like.

The present invention is preferably employed in an organic polymer having a melting point of about 300 ° C. or higher or a decomposition point lower than the melting point, which can substantially only form a solution film. The decomposition point referred to here means 5 points in thermogravimetric analysis in air flow.
It refers to the temperature at which% weight loss occurs. In particular, the film forming method of the present invention is capable of forming a thin film, and also has no adverse effect on surface characteristics and the like, so that it is suitable for forming a resin having such a strong demand, and has an appropriate flexibility in forming the thin film. It is particularly preferably employed in the formation of an aromatic polyamide or aromatic polyimide film which requires mechanical properties such as Young's modulus.

The aromatic polyamide referred to in the present invention means that the repeating unit represented by the following general formula (I) and / or the general formula (II) is more than 50 mol%, preferably 7 mol%.
It is composed of those having 0 mol% or more.

[0016]

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[0017]

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Here, as Ar ₁ , Ar ₂ and Ar ₃ , for example, those shown in Chemical Formula ₃ are exemplified.

[0019]

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In the chemical formula 3, X and Y are -O-, -CH
_{2 -, - CO -, -} SO 2 -, - S -, - C (CH 3)
_2- , -C (CF ₃ ) ₂ -or the like can be selected, but is not limited thereto.

Further, hydrogen atoms on these aromatic rings may be halogen groups, nitro groups, C1-C3 alkyl groups, C1-C3
An alkoxy group, a trialkylsilyl group, an aryl group,
When the aromatic ring substituted with a substituent such as an oxyaryl group or a thioaryl group accounts for 30% or more, preferably 50% or more, and more preferably 70% or more of the total, the moisture resistance is improved, and the dimensional change due to moisture absorption is improved. It is preferable because characteristics such as a decrease in rigidity are improved, and hydrogen on the amide group may be substituted with another substituent.

From the viewpoint of characteristics, it is preferable that the above aromatic rings bonded in a para-oriented manner account for at least 50%, preferably at least 70%, more preferably at least 75% of the total aromatic rings. The term "para-orientation" as used herein refers to a state where the divalent bonding chains on the aromatic nucleus bonded to the amide bond constituting the main chain are parallel or coaxial with each other. Such an aromatic polyamide has functions such as strength, elongation, rigidity, and heat resistance that are favorable for thinning when formed into a film or sheet. Examples of such para-oriented aromatic nuclei include those shown in the following chemical formula 4.

[0023]

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The method for obtaining such an aromatic polyamide includes:
For example, there are a low-temperature solution polymerization method, an interfacial polymerization method, a method of reacting an isocyanate and a carboxylic acid, a method of directly polycondensing using a dehydration catalyst, and the like. The low-temperature solution polymerization method is suitable because a polymer having a high degree of polymerization is easily obtained. . That is, from acid chloride and diamine, N-methylpyrrolidone (NM
Polymerize in an aprotic organic polar solvent such as P), dimethylacetamide (DMAc) or dimethylformamide (DMF). When acid chloride and diamine are used as monomers in the polymer solution, hydrogen chloride is by-produced.When neutralizing this, inorganic neutralizing agents such as calcium hydroxide, calcium carbonate, lithium carbonate, and ethylene are used. Organic neutralizing agents such as oxides, propylene oxide, ammonia, triethylamine, triethanolamine, diethanolamine and the like are used.

These polymer solutions may be used directly as a stock solution for film formation, or the polymer may be isolated once and then redissolved in the above-mentioned organic solvent or an inorganic solvent such as sulfuric acid to prepare a stock solution for film formation. Is also good.

The intrinsic viscosity of the polymer (polymer 0.1.
5 g as a 100 ml solution in sulfuric acid at 30 ° C.) is preferably 0.5 or more.

In the polymer solution, an inorganic salt is used as a dissolution aid,
For example, calcium chloride, magnesium chloride, lithium chloride, lithium nitrate and the like may be added. The polymer concentration in the polymer solution is preferably about 2 to 40% by weight.

The aromatic polyimide referred to in the present invention is a polymer having one aromatic ring and one imide ring in the repeating unit of the polymer.
And represented by the structural unit represented by the following general formula (III) and / or the general formula (IV).

[0029]

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[0030]

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Here, Ar ₄ and Ar ₆ contain at least one aromatic ring, and two carbonyl groups forming an imide ring are bonded to adjacent carbon atoms on the aromatic ring. This A
r ₄ is derived from an aromatic tetracarboxylic acid or its anhydride. Representative examples include those shown in the following Chemical Formula 7.

[0032]

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Here, Z is —O—, —CH ₂ —, —CO
_{-, - SO 2 -, -} S -, - C (CH 3) 2 - is chosen from such, but is not limited thereto.

Ar ₆ is derived from carboxylic anhydride or its halide. Examples of Ar ₅ and Ar ₇ include those shown in Chemical formula 8.

[0035]

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In formula 8, X 'and Y' are -O-,-
CH _2- , -CO-, -SO _2- , -S-, -C (CH
₃ ) It is selected from _2- and the like, but is not limited thereto. Further, some of the hydrogen atoms on these aromatic rings are substituted with substituents such as halogen groups (particularly chlorine), nitro groups, C1-C3 alkyl groups (particularly methyl groups), and C1-C3 alkoxy groups. And those in which the hydrogen in the amide bond constituting the polymer is replaced by another substituent.

Such an aromatic polyimide or polyamic acid solution can be obtained as follows. That is, polyamic acid is N-methylpyrrolidone (NMP), dimethylacetamide (DMAc), dimethylformamide (DM
It can be prepared by reacting tetracarboxylic dihydrate with an aromatic diamine in an aprotic organic polar solvent such as F). The aromatic polyimide can be prepared by heating a solution containing the above-mentioned polyamic acid or adding an imidizing agent such as pyridine to obtain a polyimide powder, which is dissolved in a solvent again. The polymer concentration in the film forming solution is 5
About 40% by weight is preferable.

Next, the solvent, which is another component of the organic polymer solution, is not particularly limited as long as the above-mentioned organic polymer can be dissolved. Although inorganic salts such as may be contained, when prepared as a film forming solution and sealed at room temperature, 1
It is preferable that no change in appearance such as turbidity or precipitation of organic polymer is observed for more than a week.

The means for preparing a solution is not particularly limited, and includes, in addition to known dissolving means, a method for directly obtaining an organic polymer solution by performing polymerization in the solvent as described above.

As long as a stable solution state can be maintained, a soluble organic substance or inorganic salt may be dissolved in the organic polymer solution. The molecular body may be mixed with a small amount of a solvent that does not dissolve alone. If necessary, lubricants, antioxidants and other additives may be blended to such an extent that physical properties are not impaired, or insoluble components such as organic or inorganic particles may be dispersed.

Next, these organic polymer solutions are cast on a cast support such as an endless belt or a drum. As a means for casting into a film or a sheet, a conventionally known means can be adopted, and a method using a T-die, an L-die, or the like is practical.

In the present invention, when the organic polymer solution is cast on the support, the polymer and the solvent mainly used for the solution (the polymer) are interposed between the support and the cast organic polymer solution membrane. This solvent is hereinafter referred to as “solution solvent”, and the following two types of mixed solvents (hereinafter, referred to as “intervening solvents”) are interposed. : A solvent that is not compatible with the organic polymer but is compatible with the solvent mainly used in the solution. : A mixed solvent comprising a solvent compatible with the organic polymer and a solvent mainly used in the solution.

The term "mainly used" as used herein means that it is used exclusively for the purpose of dissolving an organic polymer, and may be a mixed solvent of two or more kinds, and each component may be used alone. It has compatibility with organic polymers as a component. The compatibility as used herein is defined as a solvent capable of forming a solution of 1% by weight or more, preferably 10% by weight or more with respect to the organic polymer at ordinary temperature.

The intervening solvent is a mixed solvent composed of the above two kinds. One is: a solvent that is not compatible with the organic polymer but is compatible with the solvent mainly used in the solution. The other is a mixed solvent consisting of: a solvent compatible with the organic polymer and the solvent mainly used in the solution. The term "compatible with an organic polymer" as used herein is defined as a solvent capable of forming a solution of 1% by weight or more with respect to the organic polymer at room temperature. On the other hand, the term "compatible with a solution solvent" as used herein means that the solvent is completely mixed even when mixed at 10% by weight with respect to the solution solvent, that is, as a solvent which is stabilized without forming a liquid-liquid interface when a mixed solution is formed. Define.

The present invention is characterized in that such an intervening solvent is employed and is interposed between the organic polymer solution and the support at the time of casting. As a result, the casting speed, which cannot be obtained by the conventional solution casting method, can be increased.
The quality of the obtained film, for example, surface properties and flatness become extremely good.

The excellent effect of the present invention is that since the intervening solvent has an excellent affinity with the solution solvent and the polymer at the beginning of casting, the organic polymer solution membrane in which the intervening solvent film is effectively cast with the support is used. It is considered that air was prevented from being trapped by the film of the intervening solvent, and the casting speed was dramatically improved. The above-mentioned solvent among the intervening solvents is rapidly absorbed and diffused in the cast organic polymer solution, while the solvent is once dissolved in the solution solvent and is absorbed by the organic polymer solution film and the landing line However, as the solution solvent is removed, it is deposited on the organic polymer solution film to form an extremely thin thin film of the above solvent with the support. As a result, the peelability is improved, and peeling is possible even at a low polymer concentration.
It is considered that productivity and stretchability can be improved and mechanical properties such as Young's modulus can be improved well. Further, since the above-mentioned thin film is formed extremely thinly, there is no adverse effect on the surface characteristics. This effect is particularly remarkable in a dry film forming method or a dry / wet film forming method in which the organic polymer solution film is subjected to solvent evaporation at the time of heating and then stripped off, and then, if necessary, further extracting the solvent in a wet bath and performing stretching and heat treatment. is there.

When the boiling point of the above-mentioned solvent is higher than that of the solution solvent, the effect of improving the releasability and accompanying productivity or mechanical properties is remarkable. Such solvents include glycerin, polyethylene glycol, sulfolane, diethanolamine, triethanolamine.

The ratio of the solvent to the solvent is not particularly limited as long as the object of the present invention can be achieved, but the solvent is compatible as a mixed solvent and usually has a weight fraction of: =
5-95: 95-5, preferably 50-90: 50-1
It is in the range of 0.

It is preferable that the intervening solvent does not substantially remain in the film or sheet-like molded product after the completion of film formation.

Next, an embodiment of a film forming apparatus according to the present invention will be described with reference to the drawings for more detailed explanation. Of course, the present invention is not limited to this.

The film forming apparatus of the present invention comprises a means for extruding an organic polymer solution through a die or the like, an endless belt or a roll-shaped support for supporting the extruded organic polymer solution, In a film forming apparatus for obtaining a film or sheet-like molded body provided with a means for removing and forming a solvent and, if necessary, a means for gripping and extending the molded body, the extruded organic polymer solution and support are provided. Between the body: a solvent that is not compatible with the organic polymer but compatible with the solvent mainly used in the solution; A film forming apparatus characterized by having means for interposing a mixed solvent composed of a solvent having compatibility with a mainly used solvent.

First, the above-mentioned solvents are used as a mixed solvent upon application. Although it may be used as a mixed solvent immediately before application, it is usually prepared in advance.

In the film forming apparatus shown in FIG. 1, a T-die 1 as an extruding means for extruding an organic polymer solution is provided in close proximity to the T-die 1 as a support for supporting the extruded organic polymer solution. A cast drum 7 is provided. A means for interposing the above-mentioned mixed solvent between the organic polymer solution film 5 extruded from the T-die 1 and the cast drum 7, that is, a solvent applying device B is provided on the upstream side of the T-die 1. I have. The solvent application device B is movably operated by the press-contact mechanism 3 so that its position can be adjusted.

In this example, a contact device A is provided as a means for bringing the organic polymer solution film 5 into close contact with the support 7. The contact device A has an air knife nozzle 6 provided on the downstream side of the T die 1, and air is sent into the air knife nozzle 6 by a known means. The blowing pressure is controlled by the pressure gauge 2, the slit width of the air knife nozzle 6, and the like.

The solvent applicator B may be used to apply an intervening solvent onto the cast support as shown in FIG. 1 or to apply it in a non-contact manner as shown in FIGS. However, since there is no friction with the support and there is little fear of scratching, it is preferable to adopt a method of applying the toner in a non-contact manner.

As shown in FIG. 1, the contact-type solvent applying device includes, for example, a liquid feeding pump 9 and a means for supplying an intervening solvent, such as sending air into a tank to push out the intervening solvent, and an intermediary for supplying the intervening solvent. A solvent supply pipe 4, a sponge or cloth having a function of holding the intervening solvent supplied through the intervening solvent supply pipe 4 and applying the intervening solvent to the support; It is composed of a rod-shaped intervening solvent applied body 8 and an intervening solvent applied body support pressing mechanism 3 for pressing the intervening solvent applied body 8 against a cast support as required.

This will be described in more detail with reference to FIG. An intervening solvent release pipe 10 connected to the intervening solvent supply pipe 4 to supply the intervening solvent in the roll-shaped intervening solvent application body 8
Is pierced. The outer periphery of the intervening solvent discharge tube 10 has a large number of pores, and is adjusted on the liquid sending pump 9 (not shown) side so that the intervening solvent application body 8 always holds the intervening solution at a constant amount. Have been. Further, an intervening solvent application body support press-contact mechanism 3 for press-contacting the cast drum 7 while maintaining a constant pressure is connected to the interposed solvent discharge pipe 10 and the like as necessary.

FIG. 3 shows a cast belt 12 as a support for supporting the organic polymer solution film 5 and an intervening solvent applying device B.
An example using a non-contact type intervening solvent applying device will be described below.

That is, the organic polymer solution 5 extruded from the T-die 1 is extruded onto the cast belt 12 driven by the cast belt driving drum 7 '. The non-contact type solvent applying device is shown in FIG. 3B, and the spraying nozzle or the heating device,
Supply to a vaporizer or atomizer 13 composed of a vibrating membrane or the like,
Evaporation or atomization is performed, and an intervening solvent is applied onto the cast belt 12. When the intervening solvent is vaporized, the temperature of the cast belt 12 may be reduced to cause condensation on the belt.

The adjustment of the overall applied amount or the uniformity of the applied amount in the longitudinal direction is adjusted by the means for supplying the intervening solvent, that is, the side of the liquid feed pump 9 (not shown). The adjustment can be achieved by controlling the arrangement interval in the width direction in the vaporizer or atomizer 13, the back pressure and the supply amount of the intervening solvent in each unit, and the like. Further, as shown in the figure, the non-contact type solvent applying device is provided with a vaporizer or an atomizer 13 so that an excessively vaporized or atomized intervening solvent which has not adhered to the support does not leak out of the system. A chamber 14 may be provided so as to cover the air, and an intake pipe 15 connected to a suction means such as an intake blower may be provided to exhaust the exhaust gas. Also, the chamber 1 is used to prevent the coagulated or adhered solvent from dropping onto the cast support.
4, the inlet pipe 4, the suction pipe 15, and the like can be heated, and a collecting mechanism such as a gutter can be provided at the periphery of the chamber 14.

Further, in this example, a contact device A is provided as a means for bringing the organic polymer solution film 5 into close contact with the cast belt 12. The contact device A has a suction nozzle 11 provided on the upstream side of the T-die 1. The suction nozzle 6 sucks air by a known means such as a suction blower. The suction pressure, including the distribution in the width direction, is controlled by the configuration of the pressure gauge 2 and the opening of the suction nozzle 6, and the like.

FIG. 4 shows an example in which a cast drum 7 is used as a support for supporting the organic polymer solution film 5, and a non-contact type interposed solvent applying device different from FIG. Is shown.

In this example, a vaporizer using a spray nozzle, a heating device, a vibrating membrane, or the like is provided in a separately provided vaporization chamber or atomization chamber 18 instead of directly vaporizing or atomizing the intermediate solvent. Alternatively, an atomizer 13 is provided to vaporize or atomize the intervening solvent in the chamber. Then, the carrier gas is sent from the air supply pipe 16 into the vaporization chamber or the atomization chamber as needed, and
The cast drum 7 is introduced into the discharger 19 provided in the
Guided up and attached.

Also in this example, when a vaporized intervening solvent is used, the temperature of the cast support may be lowered to cause the coagulation on the cast support. Further, a chamber 14 was provided so as to cover the discharger 19 so as to prevent excessive vaporized or atomized intervening solvent that did not adhere to the support from leaking out of the system, and was connected to suction means such as an intake blower. Means for exhausting the gas by disposing the intake pipe 15 can be provided. Further, the vaporizing or atomizing chamber 1 is used to prevent the coagulated or adhered intervening solvent from dropping onto the cast support.
8, the chamber 14, the introduction pipe 4, the suction pipe 15, and the like can be heated, and a collecting mechanism such as a gutter can be provided at the periphery of the chamber 14.

FIGS. 5 and 6 show another embodiment of the present invention. That is, in the film forming apparatus shown in FIGS. 5 and 6, the T die 1 is used as an extruding means for extruding the organic polymer solution, and the T-die 1 is used as a support for supporting the extruded organic polymer solution.
A cast drum 7 is provided near the T-die 1. In these examples, an intervening solvent film is formed on the extruded organic polymer thin film side and then cast onto the cast drum 7.

FIG. 5 shows a cross section of the T-die 1. In the T-die 1, the above-mentioned mixed solvent is interposed between the organic polymer solution film 5 extruded from the T-die 1 and the casting drum 7. As a means, an intervening solvent supply thin tube 20 utilizing a capillary or a porous body connected to the intervening solvent supply tube 4 is provided below the T-die, and the intervening solvent is discharged immediately after the organic polymer solution film 5 is extruded. Applied to the solution. The amount of the intervening solvent to be applied is adjusted on the side of a liquid feed pump 9 (not shown) connected to the other end of the solvent supply pipe 4. It can be achieved by adjustment or the like.

FIG. 6 also shows a cross section of the T-die 1. In this case, as a means for allowing the mixed solvent to intervene, an intervening solvent supply pipe 4 and an intervening solvent supply thin tube 20 'are introduced into the T-die and interposed. The solvent is laminated on the organic polymer solution and discharged together from the T-die. The applied amount of the intervening solvent is adjusted on the side of a liquid feed pump 9 (not shown) connected to the other end of the solvent supply pipe 4, and the applied amount in the width direction is adjusted by changing the width of the supply pipe in the T-die. It can be achieved by appropriately adjusting the configuration.

Further, in order to increase the adhesion of the polymer solution, the adhesion device described with reference to FIGS. 1 and 2 can also be used in the system shown in FIGS.

As shown in FIGS. 1 to 4, in the present invention, it is extremely preferable to use a means for exerting a force on the polymer solution film to adhere to the support. As such means, means for sucking air to the upstream side with respect to the cast organic polymer solution film such as the above-described suction nozzle or air knife or means for blowing a working fluid such as air to the downstream side,
Known means such as a means for exerting an indirect force such as an electrostatic force or a magnetic force can be employed, and preferably has a mechanism for finely adjusting the mounting position. Of course, it may be arbitrarily combined with the solvent application device. Surprisingly, when used in combination with the present invention, the blowing pressure, suction pressure, etc., which are conventionally required for stabilization, in these means are drastically reduced. As a result, it is possible to operate at a low load even at speeds which these stabilization methods could not achieve conventionally, and the present invention, combined with this effect, enables further higher speed. Further, in the case of the close contact means utilizing the air flow, the pressure fluctuation is suppressed due to the decrease in the required pressure, which is advantageous even in thin film formation.

It is desirable that the variation in the amount of the intervening solvent on the effective surface to which the intervening solvent is applied is 30% or less, preferably 20% or less, and more preferably 10% or less. If it exceeds 30%, drying unevenness is generated particularly in the film forming means employing heat evaporation for removing the solvent, and the physical properties of the obtained film or sheet-like molded product may become nonuniform, There is a concern that will worsen. Here, the effective surface is defined as the surface that is actually cast, and the variation in the applied amount is determined by measuring the applied amount per unit area at 10 points in the longitudinal direction or the width direction, and determining the maximum deviation ratio from the average value. Is defined as The uniform application of the above-mentioned variation or less can be achieved by using the interposed solvent-applied-body supporting and pressing apparatus 3 shown in FIG.
A mechanism that can adjust the contact pressure in the width direction is used, a distributor is appropriately used in the supply pipe, the vaporizer or the atomizer 13 in FIG. 3 or the discharger 19 in FIG. 4, and a supply hole, a generator, and the like are used. Optimizing the arrangement of the supply elements,
This can be achieved by providing a partition plate inside.

When the organic polymer is extruded from the slit using a T-die or the like, the distance between the extrusion port and the cast support is 10 mm or less, preferably 5 mm or less.
More preferably, it is preferably 3 mm or less. 10
If it exceeds mm, even if an intervening solvent is used, there is little merit of speeding up, and the landing line of the extruded organic polymer solution film tends to fluctuate, which may cause uneven thickness. In addition, the thickness of both ends increases due to the occurrence of neck-in, the amount of solvent removed per unit area increases, and peeling from the support does not work well, or the physical properties of the obtained film or sheet-like molded product are uneven. This is not desirable.

In the casting, the organic polymer solution is cast while maintaining the viscosity of the solution at room temperature at 60% or less, preferably 50% or less, more preferably 40% or less. This is preferable because casting can be performed at a high speed. The reason for this is not clear, but the viscoelasticity is reduced and the effect from the moving support is reduced, or the thermal motility of the organic polymer solution component is increased and the affinity with the intervening solvent is increased. It appears to be beneficial to increase.

Although there is no particular limitation on the thickness of the film or sheet-like molded product obtained in the present invention, as described above, the prior art is particularly limited in forming a thin product, and therefore the present invention is not limited to the film or the sheet. The final thickness of the sheet-like molded body is 10 μm or less, preferably 7 μm or less, more preferably 5 μm or less, and particularly preferably 4 μm.
It is very preferably employed in obtaining:

In particular, the present invention is further excellent in the surface properties and flatness of the film or sheet-like molded product, so that a higher capacity is required, and the requirements for the surface characteristics and flatness are also strict. It is preferably used as a base material, an insulating wiring member for electric equipment such as a flexible printed circuit board, a TAB carrier tape, a solar cell board, etc., a capacitor or a transfer material for heat-sensitive recording, etc., which are becoming smaller and lighter.

In particular, since the film or sheet-like molded product obtained from the present invention has excellent surface properties, it has a measurement area of 0.002 mm ² at a cut-off value of 0.08 mm measured by an optical stylus type three-dimensional surface roughness meter. Three-dimensional surface roughness S
Ra1 and three-dimensional surface roughness SR with a measurement area of 1.0 mm ²
a2 preferably satisfies the following relationship. 0.8 ≦ SRa2 / SRa1 ≦ 4.5

SRa2 / SRa1 is preferably at most 3.5, more preferably at most 3.0. SRa2 / SR
If a1 exceeds 4.5, the surface of the base material has significant undulation on irregularities, and there are many restrictions on its use as a product.

The ratio SRa2 / SRa1 is preferably 0.9 or more, more preferably 1.2 or more. When SRa2 / SRa1 is less than 0.8, there is a concern that a processing problem may occur, and the friction durability of the final product may be adversely affected.

Further, the film or sheet-like molded product obtained by the present invention has a tensile Young's modulus in at least one direction at 20 ° C. and a relative humidity of 60% of 7.84 GPa.
It is preferred that More preferably, 8.82 GPa
Above, more preferably 9.8 GPa or more. Generally, the Young's modulus is governed by the molecular structure and the stretchability during film formation,
In order to obtain a high tensile Young's modulus, the above-mentioned para-oriented aromatic polyamide is preferably employed. Normal upper limit is 35G
A film having a value of about Pa or higher is fragile or easily ruptured, and has low industrial value. Since it can withstand the tension during use or processing, it is particularly advantageous for a thin-film molded body.

The present invention can be used for forming a single-layer film or sheet-like molded product, but is also preferably used for forming a laminated molded product. Components constituting each layer at the time of lamination may be of the same type or different.
Further, at least one layer constituting each layer may contain sub-materials such as particles which do not impair the purpose of the present invention, and the types, contents, particle diameters and the like of these sub-materials may be the same or different. There may be.

The organic polymer solution film cast through the above means is processed into a film or sheet-like molded body by a so-called solution casting method. The solution film forming method includes a dry-wet method, a dry method, a wet method and the like, and any method may be used for forming the film. Here, the dry-wet method will be described as an example.

In the case of forming a film by a dry-wet method, a conventionally known method disclosed in, for example, JP-A-54-105197 can be used. That is, the solvent is evaporated from the thin film layer of the organic polymer solution cast on the cast support and dried until the thin film has self-holding properties. Drying conditions are in the range of room temperature to 220 ° C. within 60 minutes, preferably in the range of room temperature to 200 ° C. After the dry process, the film is peeled from the support and introduced into a wet process in which desalting and desolvation are performed by an extraction medium in the same bath as in the above-mentioned wet process. In addition, stretching, drying, and heat treatment are performed. It is.

The film or sheet-like molded body formed as described above is preferably stretched while holding it with a clip in a tenter during the film forming process, or by utilizing the peripheral speed difference of a roll. Stretching is performed by a conventionally known method, and the stretching ratio is 0.8 to 8.0 in area ratio.
(The area magnification is defined as a value obtained by dividing the area of the film after stretching by the area of the film before stretching. 1 or less means relaxation.), And more preferably 1.1 to 1.1. 5.0. Also, it is effective to gradually cool the film after stretching or heat treatment.
It is effective to cool at a speed of less than a second.

The film or sheet-like molded product obtained in the present invention may be laminated,
In the case of a layer, the organic polymer solution is divided into two, and a necessary auxiliary material is added to each, and then the layers are laminated. The same applies to the case of three or more layers. As a method of lamination, a well-known method, for example, lamination in a die, lamination with a composite pipe, a method of forming one layer once and forming another layer thereon can be adopted.

[0084]

EXAMPLES Hereinafter, the present invention will be described specifically based on examples, but the present invention is not limited to the description. In addition, the measuring method used for evaluation of each Example and a comparative example is as follows.

A. Young's modulus, elongation Using Orientec Tensilon, test width 10 mm,
The test was performed at a test length of 50 mm and a tensile speed of 300 mm / min. In the measurement, the sample was placed in an atmosphere of 20 ° C. and a relative humidity of 60% for 24 hours or more, and the measurement was performed under the same conditions.

B. Surface properties The film surface was aluminum-deposited with a vacuum deposition machine, and the deposition surface was observed using a differential interference microscope to check for any defects that would pose a practical problem.

C. Thickness unevenness Using an electron beam micro thickness gauge, a length of 10 m was continuously measured in the longitudinal direction of the film, and a value obtained by dividing the difference between the maximum value and the minimum value by the average thickness was multiplied by 100 ( unit:%). In addition, thickness unevenness is less than 10% and 5%
The following were considered excellent.

D. Flatness evaluation index 50 cm x 50 cm in an environment of 25 ° C and 60% relative humidity
Is placed on a flat plate on which a thick felt or a non-woven fabric ("EXSEINE" manufactured by Toray Industries, Inc. is used in this embodiment) is spread, and the film is spread with a brush.
After standing for 15 minutes, the swelling portion is marked on the exine without contact, and its area is determined. And
The value obtained by dividing the area of the non-contact portion by the total area of the film is 1
It was determined by multiplying by 00 (unit:%). Less than 10% was regarded as good flatness, and 5% or less was regarded as excellent.

N-methylpyrrolidone (NMP), in which silica particles having an average primary particle size of 16 nm are dispersed at 0.3% by weight per polymer, 2-chloroparaphenylenediamine corresponding to 80 mol% as an aromatic diamine component and 20 mol % Of 4,4′-diaminodiphenyl ether was dissolved therein, and 100 mol% of 2-chloroterephthalic acid chloride was added thereto, followed by stirring for 2 hours to complete the polymerization. Then, the generated hydrogen chloride was neutralized by adding a quarter of the amount using lithium hydroxide, and the polymer concentration was 10%.
A weight percent aromatic polyamide solution was obtained. The value obtained by dividing the viscosity at 60 ° C. of the aromatic polyamide solution by the viscosity at room temperature is 0.37.

Example 1 As a means for extruding an organic polymer, a slit length of 400 mm was connected to a gear pump and 2 m from a stainless steel belt.
m T-die placed above, a support consisting of a mirror-polished stainless steel belt as a cast support and a cast roll for belt drive, suction of 1.5 mm slit clearance on the upstream side of the T-die as a contact means A nozzle was arranged, and then a sponge roll provided with a mechanism for supplying the intervening solvent and a mechanism for pressing the cast belt was arranged upstream of the suction nozzle as a means for applying the intervening solvent. While maintaining the same temperature from the hopper maintained at a temperature of 60 ° C., the mixture was cast on a 65 ° C. stainless belt from a T die maintained at 60 ° C. through a gear pump and a 2 μm cut filter. At this time, 90:10 of NMP prepared in advance on a cast belt from a sponge roll and polyethylene glycol 400 manufactured by Wako Pure Chemical Industries, Ltd.
Was applied so as to be 4 μm ± 0.3 μm (the error range shown in this example is based on the above-described method for measuring the applied amount per unit area on the effective surface). The pressure inside the suction nozzle was -50 mmAq.

The speed was gradually increased while adjusting the discharge rate and the speed of the cast belt so that the final film thickness was constant. Even at a casting speed of 41 m / min, the gap between the organic polymer solution film and the support was increased. Without biting the air,
The casting was performed very stably.

Next, the solvent was evaporated by heating in a dryer with hot air at 190 ° C. for 1.5 minutes while holding the cast belt, and the self-holding property was stably obtained even when the polymer concentration was 40% by weight or less. The film could be continuously peeled from the belt. After peeling the film, the film is stretched 1.1 times in the longitudinal direction and the width direction, and then the film is introduced into a heated water tank, and the residual solvent and the inorganic salt generated by neutralization are extracted with water. By drying and heat-treating the water, an aromatic polyamide film having a thickness of 3.6 μm was obtained. In the water tank, the circumferential speed of the roll was changed to change the roll length in the longitudinal direction of the film.
The film was stretched 25 times, dried and stretched while holding it with a clip in a tenter at 280 ° C. for 1.5 minutes, and stretched 1.3 times in the width direction. Then, at a fixed length of 290 ° C., 30
After performing the heat treatment for 2 seconds, it was gradually cooled at a rate of 20 ° C./second.

The SRa2 / SRa1 of this base film was 1.7, and the Young's modulus was 14 GP in each of the longitudinal direction and the width direction.
a, 14 GPa and elongation were 35%.

In addition, there is no problem in the surface properties.
The thickness unevenness was 3%, and the flatness evaluation index was 3%, which was excellent in practical use.

Example 2 Casting was performed on a cast belt in the same manner as in Example 1 except that the pressure inside the suction nozzle was set to 0 mmAq. After gradually increasing the speed while adjusting the discharge amount and the speed of the cast belt so that the final film thickness is constant,
Even at a casting speed of 25 m / min, air could not be trapped between the organic polymer solution film and the support, and the casting could be performed extremely stably.

Next, the conditions were adjusted to the same conditions as in Example 1 to obtain an aromatic polyamide film having a thickness of 3.6 μm. The SRa2 / SRa1 of this base film is 1.
4. The Young's modulus is 14 GPa in the longitudinal and width directions, respectively.
The elongation was 14 GPa and the elongation was 33%.

Further, there was no problem in the surface properties of this film, and the thickness unevenness was 5% and the flatness evaluation index was 4%.

Example 3 Example 1 was repeated except that the temperature of the aromatic polyamide solution and the supply system of the solution up to the die and the temperature of the cast belt were kept at room temperature.
When the cast was examined in the same manner as in the above, air entrapment was observed at 37 m / min. A film having a thickness of 3.6 μm was obtained in the same manner as in Example 1, but the mechanical properties, flatness, surface properties, and thickness unevenness were comparable to those of Example 1.

Example 4 In Example 1, as a means for supplying the intervening solvent,
The solvent used in the above was provided on the upstream side of the suction nozzle via a supply tank, a nozzle type sprayer connected to a supply pump, an atomizing chamber equipped with a transfer air inlet through a blower and a filter, and an outlet for an atomizer. The outlet of the atomized body connected to the inside of the chamber (a gutter is provided on the periphery to prevent the condensate from falling onto the cast belt) is 2 mm from the cast belt.
It is provided above. ) Indirect supply means were used instead. At this time, the amount of water applied on the cast belt was 4 μm.
m ± 0.1 μm.

Next, the speed was gradually increased while adjusting the discharge rate and the speed of the cast belt so that the final film thickness was constant. When the casting speed was 41 m / min, the distance between the organic polymer solution film and the support was increased. Casting could be performed extremely stably without air being trapped in the air.

Thereafter, the conditions were adjusted to the same conditions as in Example 1 to obtain an aromatic polyamide film having a thickness of 3.6 μm. The SRa2 / SRa1 of this base film is 1.
4. The Young's modulus is 14 GPa in the longitudinal and width directions, respectively.
The elongation was 14 GPa and the elongation was 30%. This film was comparable to the film of Example 1 in flatness, surface properties, thickness unevenness, and the like.

Comparative Example 1 The same apparatus system as in Example 1 was used except that the supply mechanism of the intervening solvent was removed and the intervening solvent was not applied onto the cast belt. When the speed was gradually increased while adjusting the discharge amount and the speed of the cast belt so that the final film thickness became constant, the pressure in the suction nozzle became -50 mmAq.
In the case of, air was caught at 13 m / min, and it was impossible to form a film. Next, while increasing the pressure in the suction nozzle, the discharge amount and the speed of the cast belt were adjusted so that the final film thickness was constant, and the speed was increased.
Even at 0 mmAq, air entrapment occurs from 20 m / min, and when the pressure in the suction nozzle is further reduced, the vibration of the organic polymer solution film to be ejected becomes large, and the occurrence of non-negligible thickness unevenness has come to be recognized. .

With respect to the film cast at the above-mentioned belt speed of 13 m / min, the conditions were adjusted to the same conditions as in Example 1 to obtain an aromatic polyamide film having a thickness of 3.6 μm. The SRa2 / SRa1 of this base film is 1.8, and the Young's modulus is 13 GP each in the longitudinal direction and the width direction.
a, 13 GPa and elongation were 41%. Although the surface properties of this film are not problematic in practice, the unevenness in thickness is 1%.
It was 3% and the flatness evaluation index was 12%, which was not practically satisfactory.

Comparative Example 2 In Comparative Example 1, casting was performed with the suction nozzle pressure being further reduced to 0, but air was caught at 7 m / min.

[0105]

According to the present invention, by adopting the above-mentioned structure, the problem of high-speed film formation in solution film formation, which has been difficult until now, can be achieved even at a high speed even with a thin film. In addition, the present invention can make the obtained film or sheet-like molded article excellent in surface properties and flatness. In addition, an effect of improving productivity or mechanical characteristics such as an effect of improving peelability and stabilizing a landing line can be expected.

The film or sheet-like molded body thus obtained can be used as a printing material such as an optical member, an optical recording medium, a magnetic recording medium, an insulating wiring member for electric equipment, a capacitor, a coating material, a plate-making material, and the like. It can be suitably used for various uses such as a film.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a film forming apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a contact part of a cast support of the contact type solvent applying apparatus in the apparatus of FIG.

FIG. 3 is a schematic configuration diagram of a film forming apparatus according to another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a film forming apparatus according to still another embodiment of the present invention.

FIG. 5 is a sectional view of a T-die portion of a film forming apparatus according to still another embodiment of the present invention.

FIG. 6 is a sectional view of a T-die portion of a film forming apparatus according to still another embodiment of the present invention.

[Explanation of symbols]

 A: Adhesion device B: Solvent application device 1: T die 2: Pressure gauge 3: Intermediate solvent applied body supporting pressure contact mechanism 4: Intervening solvent supply pipe 5: Organic polymer solution film 6: Air knife nozzle 7: Cast drum 7 ' : Cast belt driving drum 8: Interposed solvent application body 9: Liquid sending pump 10: Interposed solvent discharge pipe 11: Suction nozzle 12: Cast belt 13: Vaporizer or atomizer 14: Chamber 15: Intake pipe 16: Air supply pipe 17: Introducing pipe 18: Vaporization chamber or atomization chamber 19: Discharger 20, 20 ': Intermediate solvent supply thin tube

Claims (13)

[Claims] 1. A method for obtaining a film or a sheet-like molded product by casting an organic polymer solution on a support, comprising: between the support and the cast organic polymer solution film: A solvent that is not compatible with the polymer but is compatible with the solvent mainly used in the solution; and a solvent mainly used in the organic polymer and the solution. A film forming method characterized by casting by interposing a mixed solvent comprising a solvent having compatibility with the film. 2. The film forming method according to claim 1, wherein a boiling point of the solvent is higher than a boiling point of a solvent mainly used in the organic polymer solution. 3. The method according to claim 1, wherein the organic polymer solution is cast using means for adhering to the support.
Or the film forming method according to 2. 4. The film forming method according to claim 1, wherein the organic polymer solution is cast at a temperature that is 60% or less of the viscosity of the solution at room temperature. Method. 5. The film forming method according to claim 1, wherein the variation in the amount of the solvent to be applied to the effective surface is set to 30% or less of the average value. 6. The film forming method according to claim 1, wherein the distance between the extrusion port of the organic polymer solution and the support is 10 mm or less. 7. The method according to claim 1, wherein the organic polymer is an aromatic polyamide and / or
7. The film forming method according to claim 1, wherein the film is an aromatic polyimide. 8. The film forming method according to claim 1, wherein the organic polymer solution is cast so that the final thickness of the film or sheet-like molded product is 10 μm or less. 9. A film or sheet comprising a means for extruding an organic polymer solution, a support for supporting the extruded organic polymer solution, and means for removing and forming a solvent in the solution. In a film forming apparatus for obtaining a molded product, a solution between the extruded organic polymer solution and the support: a solvent which is not compatible with the organic polymer but is mainly used for the solution A solvent having compatibility with the organic polymer and a solvent having compatibility with the solvent mainly used in the solution; Membrane equipment. 10. The film forming apparatus according to claim 9, wherein the means for interposing a solvent between the organic polymer solution and the support is a means for applying the solvent on the support. . 11. The film forming apparatus according to claim 10, wherein the means for applying a solvent on the support is a means for indirectly applying a solvent. 12. The means for interposing a solvent between the organic polymer solution and the support is a means for applying the solvent onto the organic polymer solution film at the time of or immediately after the extrusion of the organic polymer solution. The film forming apparatus according to claim 9, wherein: 13. The method according to claim 9, further comprising means for bringing the organic polymer solution into close contact with the support.
The film forming apparatus according to any one of the above.