JPH06345882A - Film and its production - Google Patents

Abstract

PURPOSE:To prepare a film low in specular gloss, excellent in adhesive properties and printability, using an aromatic polyamide of straight configuration excellent in heat resistance and mechanical properties. CONSTITUTION:The objective film consisting of an aromatic polyamide of straight configuration >= 3.5 in logarithmic viscosity, has the following characteristics: (1) omnidirectional Young' s modulus: >= 800 kh/mm<2>, (2) omnidirectional tensile elongation: >= 10%, and (3) surface specular gloss (Gs (60 deg.C)): <=20 %. In producing this film, a wet film after washing with water is subjected to pressure contact with a sattin-finished surface followed by drying the film under restricting its shrinkage; or, the original film is sprayed with sand 0.05-0.7 mm in the maximum particle diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film composed of a linear coordinating aromatic polyamide and a method for producing the same, and more specifically to a matte linear coordinating aromatic polyamide film having excellent mechanical properties, and The present invention relates to a manufacturing method thereof.

[0002]

2. Description of the Related Art Linear coordination aromatic polyamide films have particularly excellent crystallinity and high melting points, and because of their rigid molecular structure, they have high heat resistance and high mechanical strength. It is a polymer material that has been receiving attention. Fibers spun from a concentrated solution exhibiting its optical anisotropy have been reported to exhibit high strength and Young's modulus, and have already been industrially implemented, but there are few proposals for application to films, There are few practical applications.

The problem with linearly coordinated aromatic polyamide films is that their useful high molecular weight polymers are poorly soluble in organic solvents and strong inorganic acids such as concentrated sulfuric acid must be used as the solvent. In order to avoid this, for example, in JP-B-56-45421, a halogen group is introduced into the aromatic nucleus of a linearly coordinated aromatic polyamide to make it soluble in an organic solvent, and then a film is obtained. Attempts have been made to try. However, this is costly because the monomer is expensive, and also has the drawback of impairing the heat resistance and crystallinity of the straight-chain coordinating aromatic polyamide.

On the other hand, Japanese Patent Publication No. 59-14567 discloses a method of extruding an aromatic polyamide solution having optical anisotropy into a coagulating bath from a slit through a short air layer. Only the mechanical strength in the MD direction was strong, and the mechanical strength in the TD direction orthogonal to it was extremely weak, and only those which were easy to tear were obtained. Thus, if the optically anisotropic dope of the aromatic polyamide is simply extruded and coagulated as it is, it is likely to be fibrillated because it is excessively oriented in the discharge direction and weak in the TD direction. Various methods for producing the film to be produced have been studied.

For example, in JP-B-57-35088, an aromatic polyamide solution having optical anisotropy is extruded from a ring die and simultaneously cast in a dope state in a biaxial direction by an inflation method. Later, it is said that an isotropic film can be obtained by wet coagulation. However, it is difficult to obtain a transparent film having a uniform thickness by this method, and there is a drawback that mechanical strength, particularly tear strength, is low.

Further, in JP-B-59-5407 and JP-A-54-132674, a dope having an optical anisotropy of a linear coordinating aromatic polyamide is biaxial in a die in a direction perpendicular to an extrusion direction. I have proposed to orient it in the direction,
The structure of the die is complicated and there are difficulties in industrial implementation. Japanese Examined Patent Publication No. 57-18886 discloses a transparent and mechanical physical property by heating a dope having an optical anisotropy of a linear coordination aromatic polyamide until it becomes optically isotropic immediately before coagulation and then coagulating it. To obtain a film which is isotropic. This method is an original method that is contrary to most of the conventional concepts that high performance is obtained by utilizing the optically anisotropic dope, so that the extreme uniaxial orientation of the optically anisotropic dope is obtained. At the same time as the above relaxation, it has succeeded in avoiding that the optically anisotropic dope liquid crystal domain structure remains after the dope is extruded and is solidified as it is to become an opaque film. In addition, Japanese Patent Publication No. 3-52776
In the publication, an optically anisotropic dope of polyparaphenylene terephthalamide (hereinafter referred to as PPTA) is heated and / or moisture-absorbed until it becomes optically isotropic immediately before solidification, and then solidified in the presence of sulfuric acid. Disclosed is a film which is slippery by pressing a matte surface on one surface of a coagulated film, is transparent, and has isotropic mechanical properties. However, since it is carried out in the presence of sulfuric acid, there is a drawback that the material of the matte surface is limited and industrially difficult to carry out, and the cost becomes high.

Further, nothing is disclosed regarding a film having a small specular gloss.

[0008]

An object of the present invention is to use a linearly coordinated aromatic polyamide, which has already been industrially produced, and has a low specular gloss, good adhesiveness, and printability. The present invention provides a film excellent in high Young's modulus and high in elongation and a method for producing the film.

[0009]

Means for Solving the Problems The inventors of the present invention have earnestly studied to obtain a linear coordination aromatic polyamide film in line with the above object, and have obtained the following findings. That is, the technique disclosed in JP-B-57-17886 (a method of forming a transparent machine by a method in which an optically anisotropic dope of a linear coordination aromatic polyamide is first prepared and then optically isotropically solidified) In order to obtain a linear coordination aromatic polyamide film with excellent optical performance), the wet film after washing is pressed against the satin surface, and the shrinkage of the film is restricted to dry the film. It was found that a film having a low gloss and excellent printability and good adhesion was obtained.

The present inventors have completed the present invention through further research based on these findings. That is, the first aspect of the present invention is a film made of a linearly coordinated aromatic polyamide having an inherent viscosity of 3.5 or more, a Young's modulus in all directions of 800 Kg / mm ² or more, and a tensile strength in all directions. The film has an elongation of 10% or more and a specular gloss Gs (60 °) of the film surface of 20% or less.

The second aspect of the present invention is to provide an optical anisotropy dope which is substantially composed of a linearly coordinated aromatic polyamide having an inherent viscosity of 3.5 or more and sulfuric acid of 95% by weight or more, to obtain an optical anisotropy. In a method for producing a film, which is cast on a supporting surface while keeping it, absorbs moisture and / or, and is converted into an optically isotropic mixture by heating, then coagulates and rinses with water, the linearly coordinated aromatic polyamide is washed with water. A method for producing a film, which comprises contacting a satin surface with a wet film having a weight ratio of 0.5 to 3.0 and then drying the film while limiting shrinkage of the film.

A third aspect of the present invention is a linearly coordinated aromatic polyamide film having an inherent viscosity of 3.5 or more and a maximum diameter of 0.0.
It is a method for producing a film, which comprises spraying a sand of 5 to 0.7 mm. The film used in the present invention is composed of substantially linearly coordinated aromatic polyamide. The linearly coordinating aromatic polyamide refers to a polymer having a repeating structure in which the para position of an aromatic ring or a position corresponding thereto is linked by an amide group. This linearly coordinated aromatic polyamide is generally a poly-p-phenylene terephthalamide (P
PTA) is most often used, and is produced by a low temperature solution polymerization method from conventionally known para-phenylenediamine and terephthalic acid chloride. In addition to PPTA, for example, 4,4′-diphenylene, 1,4′-naphthalene, 1,5-naphthalene, 2,6-naphthalene, 4,4′-diene for the purpose of further improving moldability and the like. Substitution of the p-phenylene group with phenylene ether, 3,4'-diphenylene ether and substitution products of these halogen, alkyl, nitro and the like, introduction of the above-mentioned substituent to the p-phenylene group, etc. are carried out. Good. Also, poly-p-benzamide can be used.

If the degree of polymerization of the polymer of the present invention is too low, a film having good mechanical properties cannot be obtained.
3.5 or more, preferably 4.5 or more, logarithmic viscosity ηinh
(Dissolve 0.2g of polymer in 100ml of sulfuric acid at 30 ℃
The degree of polymerization that gives the value (measured in step 1) is selected. The film of the present invention can achieve its purpose only when the following three requirements are satisfied.

First, the film of the present invention has Young's modulus of 800 Kg / mm ² or more in all directions.
This requirement is related to the waist, or deformation resistance, of the film. For example, when it is used as a tracing paper for drawing, it is possible to draw a drawing on a thin film and save the storage space. Young's modulus is 1000
It is Kg / mm ² or more. Further, it is necessary that the Young's modulus in all directions is large in terms of curl and the like.

Secondly, the film of the present invention must have a tensile elongation of 10% or more in all directions. This is because a film having an elongation of less than 10% easily tears and is not practical. On the other hand, the PPTA film produced by the method described in JP-B-55-14170 has an elongation in the MD direction of at most 4 to 6% and an elongation in the TD direction of less than 1%, which is extremely low. Easy to tear. The high elongation of the film of the present invention is associated with the process of casting an optically anisotropic dope on a support surface and then making it optically isotropic.

Thirdly, the film of the present invention is a matte surface having a specular gloss Gs (60 °) of 20% or less. When Gs (60 °) exceeds 20%, the printability is deteriorated, the drawing becomes difficult to draw, and the adhesiveness is deteriorated. In addition, the slipperiness of the film is impaired, which is not preferable. Specular gloss Gs (60 °) is JIS Z87
41 can be measured. For example, a digital variable angle gloss meter UGV-4D (manufactured by Suga Test Instruments) can be used. The matte film having a specular gloss Gs (60 °) of 20% or less is a method in which a washed film having a specific water content is subjected to contact pressure treatment with a satin surface and then dried, or JP-B-57-17.
The film obtained by the technique disclosed in Japanese Patent No. 886,
Obtained by spraying sand with a specific diameter. The whiteness Y value, which is an index of the whiteness of the film, is not limited, but the larger the value, the clearer the drawing becomes. Therefore, it is usually 15% or more, preferably 20%.
% Or more. This Y value is the Y value in the tristimulus values XYZ relating to the color specified in JIS Z8701,
For example, it can be measured using a colorimetric color difference meter (manufactured by Suga Test Instruments Co., Ltd.).

The film of the present invention may be colored, and the method for coloring is not limited.
It is made by a method of adding a pigment to the dope or a method of dyeing a film. The film of the present invention usually has a density in the range of 1.370 to 1.405 g / cm ³ .
This density value is measured at 30 ° C. by a density gradient tube method using carbon tetrachloride-toluene. This density range is considerably smaller than that of the known linearly coordinated aromatic polyamide fiber which is in the range of 1.43 to 1.46 g / cm ³ . The density is 1.370 g / c
If it is less than m ³ , mechanical properties are deteriorated, and 1.405 g /
If it exceeds ³ cm, the film has mechanical properties impaired. In any case, since the density is small like this,
A light and high-strength film will be obtained.

Next, a method for obtaining such a linear coordination aromatic polyamide film will be described by taking PPTA as an example. A suitable solvent for adjusting the dope used for molding the film of the present invention is sulfuric acid having a concentration of 95% by weight or more. If the sulfuric acid content is less than 95%, it will be difficult to dissolve or the dope after dissolution will have an abnormally high viscosity. The dope of the present invention may contain a small amount of chlorosulfuric acid, fluorosulfuric acid, phosphorus pentoxide, trihalogenated acetic acid or the like. 1 for sulfuric acid
Although it can be 100 wt% or more, a concentration of 98 to 100 wt% is preferably used from the viewpoint of stability and solubility of the polymer.

The concentration of the polymer in the dope used in the present invention is preferably such that it exhibits optical anisotropy at room temperature or higher, specifically about 10% by weight or more, preferably about 10% by weight. Used at 12% by weight or more.
At a polymer concentration lower than this, that is, at a polymer concentration that does not exhibit optical anisotropy at room temperature or higher, not only the dope has a high viscosity but cannot be molded, but also the molded PPTA film does not have favorable mechanical properties. There are many. The upper limit of the polymer concentration of the dope is not particularly limited, but is usually 20% by weight or less, preferably 18% by weight or less, and more preferably 16% by weight or less for PPTA having a particularly high ηinh.

The dope of the present invention contains the usual additives such as extenders, delusterants, UV stabilizers, heat stabilizers,
Antioxidants, pigments, solubilizing agents, etc. may be mixed. Whether the dope is optically anisotropic or isotropic is determined by a known method,
For example, it can be examined by the method described in JP-B-50-8474, but its critical point depends on the type of solvent and polymer, temperature, polymer concentration, polymerization degree of polymer, content of non-solvent, etc. By investigating these relationships in advance, it is possible to change the optical anisotropy to the optical isotropy by making an optically anisotropic dope and changing the conditions to be the optically isotropic dope.

In the dope used in the present invention, insoluble dust, foreign matter, etc. are removed by filtration etc. as much as possible prior to molding and solidification, and gases such as air generated or trapped during melting are removed. It is preferable to keep. Degassing can be performed after the dope has been prepared,
Consistent vacuum (reduced pressure) from the preparation of raw materials for preparation
It can also be achieved by doing the following: The dope can be prepared continuously or batchwise.

The dope prepared as described above is produced from a die, for example, a slit die, while maintaining the optical anisotropy.
Cast on a support surface. Further, in the laboratory, it can be cast on a glass plate with a doctor knife. In the present invention, even if the steps of casting and subsequent conversion to optical isotropic, coagulation, washing, stretching, and drying are continuously performed, all or part of these are intermittently, that is, in a batch system. You can go. Preferred is a method of continuously performing the casting process.

The supporting surface used in the present invention is in the form of a belt or a drum, or is used as a plate. The material is not particularly limited as long as it has acid resistance and can be surface-finished, for example, glass, hastelloy, tantalum,
Gold, platinum, titanium nitride, and the like, and metals plated with these are preferably used, and particularly preferably, these materials are so-called mirror-finished.

The method for obtaining the film of the present invention is to cast the dope on the support surface and then convert the dope from optical anisotropy to optically isotropic prior to solidification. In order to make the optical anisotropy from the optical anisotropy, specifically, the optically anisotropic dope cast on the support surface is solidified prior to coagulation to reduce the concentration of the solvent that forms a dope to reduce the concentration of the solvent. It is converted to an optically isotropic region by the change of the dissolution capacity and the polymer concentration, or the temperature of the dope is raised by heating to convert the phase of the dope to be optically isotropic, or moisture absorption and heating are used simultaneously or sequentially. Can be achieved by In particular,
The method of utilizing moisture absorption, including the method of using heating in combination,
It is useful because the optical anisotropy of the optical anisotropy can be efficiently performed without causing the decomposition of PPTA.

To absorb the moisture of the dope, air having a normal temperature and humidity may be used, but preferably, humidified or heated humidified air is used. The humidified air may contain water in a mist state in excess of the saturated vapor pressure, or may be so-called steam. However, supersaturated steam having a temperature of about 45 ° C. or lower is not preferable because it often contains large granular condensed water. Moisture absorption is usually from room temperature to about 180 ° C, preferably 50 ° C to 15 ° C.
It is performed with humidified air at 0 ° C.

In the case of the heating method, the heating means is not particularly limited, and examples thereof include a method of applying the humidified air to the casting dope, a method of irradiating an infrared lamp, and a method of dielectric heating. The cast dope that is optically isotropic on the support surface then undergoes solidification. In the present invention, a sulfuric acid aqueous solution of 30% by weight or more can be used as the coagulating liquid of the dope.

In the present invention, the temperature of the coagulating liquid needs to be 10 ° C. or lower. This is because it is found that the lower this temperature is, the smaller the solidification rate can be and the less voids are contained in the film, and thus the higher the surface accuracy of the film is. Since the solidified film contains acid, washing the acid component to produce a film that has less deterioration in mechanical properties due to drying and heating,
It is necessary to remove as much as possible. Specifically, it is desirable to remove the acid component up to about 500 ppm or less. Water is usually used as the cleaning liquid, but if necessary, warm water may be used, or neutralization cleaning with an alkaline aqueous solution may be performed, followed by cleaning with water or the like. The cleaning is performed by, for example, running the film in the cleaning liquid or spraying the cleaning liquid.

The method for producing a colored film is not limited, but a method in which a dye or a pigment is added to a film forming solution of PPTA, a wet film before drying or a film after drying is brought into contact with a liquid containing the dye. The method of dyeing can be used, but from the viewpoint of processability, color fastness, film performance and the like, a method of contacting a liquid containing a dye with a wet film before drying and then dyeing is preferably used.

It is necessary to bring the washed film into contact with the satin surface in a state where the weight ratio of the water remaining in the film to the polymer is in the range of 0.5 to 3.0. The contact pressure treatment may be carried out in water after taking out from the washing bath as long as the weight ratio of the water remaining in the film to the polymer is within the above range. The surface that comes into contact with the matte surface is determined according to the intended use of the film and is not limited, and may be one surface or both surfaces. The surface roughness of the matte surface is not particularly limited, but an uneven surface of about 15 to 20 μm is preferably used. The material of the matte surface is not particularly limited, and may be made of rust-resistant stainless steel, hastelloy, glass, rolls with abrasives, water-resistant sandpaper, and the like, and an acid-resistant material is not particularly required. The magnitude of the contact pressure is not particularly limited, and usually the linear pressure is about 0.1 to 20 Kg / cm. For example, when the running film is continuously applied to the running film, the contacting process can be performed via a satin roll, or may be applied to each side or both sides simultaneously. Further, at the time of the contact pressure treatment, one side of the film may be pressed by another roll (a roll made of a soft material such as rubber). When the weight ratio of the water remaining in the film to the polymer is 0.5 or less, the pressure for contacting the matte surface must be increased, which causes plastic deformation of the film itself, which is not preferable. If the weight ratio of the water remaining in the film to the polymer is 3.0 or more, the stiffness of the film becomes extremely weak and wrinkles are likely to occur when the film is brought into contact with the matte surface, which is not preferable.

The film washed with water and subjected to the contact pressure is then dried. Stretching before being subjected to drying is not particularly limited and is a preferable mode for improving mechanical properties, particularly Young's modulus. It is necessary to perform stretching in a wet state before drying, and effective stretching cannot be performed after sulfuric acid remains or after drying. The drying needs to be performed under tension, under constant length or while slightly stretching while limiting the shrinkage of the film. If a film having a tendency to shrink with the removal of a washing liquid (for example, water) is dried without any restriction of shrinkage, it may be because microscopically non-uniform structure formation (crystallization etc.) occurs. The light transmittance of the film may be reduced, the flatness of the film may be impaired, and the film may be curled. In order to dry the film while limiting the shrinkage of the film, it is possible to use, for example, a tenter drier or a dry process by sandwiching it in a metal frame. Other conditions relating to drying are not particularly limited, and a method using a heated gas (air, nitrogen, argon, etc.) at room temperature,
It can be freely selected from a method using radiant heat such as an electric heater or an infrared lamp, a method such as dielectric heating, and the drying temperature is not particularly limited, but may be room temperature or higher. However, in order to increase the mechanical strength, high temperature is preferable, 100 ° C. or higher, more preferably 20 ° C. or higher.
A temperature of 0 ° C. or higher is used. The maximum drying temperature is not particularly limited, but is preferably 500 ° C. or lower in consideration of drying energy and polymer decomposability.

Further, another method for obtaining the film of the present invention will be described. In the present invention, in order to obtain a film with excellent performance, let alone dope,
Gas for moisture absorption, gas for heating, support surface, coagulating liquid, cleaning liquid,
It is preferable to reduce the content of dust such as dry gas and dust as much as possible. In this respect, it is also one of the preferred embodiments to produce the film of the present invention in a clean room or clean water.

Another method for obtaining the film of the present invention is to spray a film having a maximum diameter of 0.05 to 0.7 mm onto the film obtained by the technique disclosed in Japanese Patent Publication No. 57-18886. That is, the generally known sandblast method can be used. The method of spraying the sand is not limited, but for example, a method of spraying the sand by mixing it with a high-speed air stream from a thin slit-like gap on a film surface that continuously runs on the roll or in the air between rolls is used. To be If the maximum diameter of the sprayed sand is smaller than 0.05 mm, the effect will be extremely small. On the contrary, if the maximum diameter is larger than 0.7 mm, the film will be seriously damaged and the mechanical properties will deteriorate, or the film will have holes. However, it is not preferable especially when the film is thin. After spraying the sand, it is necessary to wash the sand attached to the film. The cleaning solution is not limited, but hydrofluoric acid is preferably used to remove the sand that has dipped into the film, and the method of cleaning with water while rubbing with a soft brush that does not damage the film, etc. Is used. When hydrofluoric acid or the like is used as the cleaning liquid, it is necessary to sufficiently wash with water so that hydrofluoric acid or the like does not remain. Films that have been washed to remove sand then need to be dried. The drying method is not limited, and may be fixed length or free, and is usually performed between rolls arranged in a dryer. Other conditions related to drying are not particularly limited, and can be freely selected from methods such as heating gas (air, nitrogen, argon, etc.) at room temperature, using radiant heat from electric heaters and infrared lamps, and dielectric heating methods. The drying temperature is not particularly limited, but may be room temperature or higher. However, in order to dry the water on the roughened surface, 100
If the temperature is higher than or equal to ℃ and the temperature is low, it is difficult to remove the water in the sandblasted gaps, so the temperature is preferably higher.

[0033]

EXAMPLES Examples and Reference Examples (Production Examples of PPTA) are shown below, but these Reference Examples and Examples explain the present invention and do not limit the present invention. In the examples, unless otherwise specified, parts by weight or% by weight is shown. Logarithmic viscosity ηinh is 98% sulfuric acid 100
0.2 g of the polymer was dissolved in ml and measured at 30 ° C. by a conventional method. The dope viscosity was 0.5 rpm using a B type viscometer.
It was measured at the rotation speed of. The film thickness is
It was measured with a dial gauge having a measuring surface with a diameter of 2 mm. The strong elongation and Young's modulus are measured by measuring a sample having a size of 100 mm × 10 mm using a constant-speed extension type strong elongation tester at a measurement length of 30 mm and a pulling speed of 30 mm / min. Specular gloss Gs (60 °) is a digital variable angle gloss meter U
It measured using GV-4D (made by Suga Test Instruments). The density is 3 by the density gradient tube method using carbon tetrachloride-toluene.
It is measured at 0 ° C. The Y value was measured using a colorimeter color computer SM-4 (manufactured by Suga Test Instruments Co., Ltd.).
The adhesive strength is 100 ° C in the treated film in an air oven.
Preliminary drying for 1 minute with a copper foil (35 μm thickness made by Mitsui Kinzoku) and an adhesive (TB 1650 made by ThreeBond) to prepare a copper clad laminate, which is heated to 100 ° C in an air oven.
Cured for 2 hours at 150 ° C. for 6 hours. This sample was cut in a width of 1 cm in the MD direction, and was obtained from the resistance force when 90 degree peeling was performed at a test speed of 50 mm / min in a tensile tester. The maximum diameter of the sand was measured at 100 times with a microscope (manufactured by Olympus) using an eyepiece scale. Reference Example (Production of PPTA) PPTA was obtained by the low temperature solution polymerization method as follows. N-methylpyrrolidone 1000 in the polymerization apparatus disclosed in Japanese Patent Publication No. 53-43986.
70 parts of anhydrous lithium chloride was dissolved in 4 parts, and then 48.6 parts of paraphenylenediamine was dissolved. After cooling to 8 ° C., 91.4 parts of terephthaloyl dichloride was added at once in powder form. The polymerization reaction product solidified into a cheese after a few minutes, so the polymerization reaction product was discharged from the polymerization apparatus according to the method described in JP-B-53-43986, immediately transferred to a biaxial closed type kneader, and polymerized in the kneader. The reaction was finely ground. Next, the finely pulverized product was transferred into a Henschel mixer, added with approximately the same amount of water for further pulverization, filtered, washed several times in warm water, and dried in hot air at 110 ° C. ηinh
95 parts of a pale yellow polymer of 5.8 was obtained. A polymer having a different ηinh can be easily obtained by changing the ratio of N-methylpyrrolidone and the monomers (paraphenylenediamine and terephthalic acid dichloride), and / or the ratio between the monomers.

[0034]

Example 1 ηinh = 6.% in concentrated sulfuric acid having a concentration of 99.5%.
1 of PPTA was dissolved at 60 ° C. to prepare a stock solution having a polymer concentration of 12%. When the viscosity of this stock solution was measured at 60 ° C., it was 4600 poise. This stock solution had optical anisotropy. The stock solution was degassed under vacuum while maintaining it at 60 ° C. The solution was sent from the tank through a filter and sent by a gear pump, and the dope was cast from a T-die having a 0.4 mm × 700 mm slit on a mirror-polished tantalum belt, with a relative humidity of about 5% and a temperature of about 105 ° C. The air was blown to the casting dope to make it optically isotropic, and the cast dope was introduced into a 50% sulfuric acid aqueous solution at 5 ° C. and coagulated with the belt. Then, the coagulated film was peeled off from the belt and washed by running in warm water of about 30 ° C., then in 0.5% NaOH aqueous solution, and further in water at room temperature. The washed film was taken out, dried, and the amount of water was measured to find that it contained 2.5 parts of water based on the polymer. This film containing water is passed between a roll with # 800 waterproof sandpaper and a roll with 5 mm thick NBR,
After press-pressing 3 times with a linear pressure of Kg / cm, 100 mm
The film was sandwiched between square metal frames, fixed with clips, and dried at 350 ° C. to obtain a one-sided matte film. When the characteristics of this film were measured, the thickness was 24 microns, MD strength was 32 kg / mm ² , TD strength was 30 kg / mm ² , MD elongation was 18%, TD elongation was 17%, and MD Young's modulus was 1230 kg.
/ Mm ² , TD Young's modulus 1200 Kg / mm ² , density 1.398 g / cm ³ , specular gloss Gs (6
0 °) was 4.8% and the Y value was 21.3%. A line was drawn on the matte surface of this film with a pencil having a hardness of HB, and it was possible to draw it neatly, and the adhesive force was 2.1 Kg / cm.

[0035]

[Example 2] Using the same stock solution as in Example 1, a film washed under the same film-forming and washing conditions was continuously stretched by 1.1 times in the longitudinal direction, and then stretched in the transverse direction by a 1.15 times tenter. After that, dry it at 200 ° C with a fixed length while sandwiched in a tenter, pass it through a hot plate with a fixed length of 400 ° C while sandwiched between the tenter, trim the ears, and wind a 20-inch wide film. It was When the characteristics of the obtained film were measured, the thickness was 12 microns and the MD strength was 42 kg.
/ Mm ² , TD strength 43 kg / mm ² , MD elongation 48
%, TD elongation 46%, MD Young's modulus 1350 Kg / mm
² , TD Young's modulus 1330 Kg / mm ² , density 1.40
It was 2 g / cm ³ . The maximum diameter of this film is 0.1
Sandblasting was performed using a device capable of spraying 5 times at a speed of 10 m / min with a sand of ~ 0.4 mm. After that, hydrofluoric acid wash in the line, after washing with water, 120 ℃
The film, which had been dried at 1, was matted on one side and continuously wound up. When the characteristics of the obtained film were measured, the thickness was 11 microns, the MD strength was 30 Kg / mm ² , and the TD strength was 29 Kg /
mm ² , MD elongation 16%, TD elongation 18%, MD Young's modulus 1280 Kg / mm ² , TD Young's modulus 1260 Kg /
The surface area was mm ² , the density was 1.399 g / cm ³ , the specular gloss Gs (60 °) of the matte surface was 7.2%, and the Y value was 22.6%. A line with a pencil of HB hardness was drawn on the matte side of this film, and it could be drawn neatly, and the adhesive strength was 1.9K.
It was g / cm.

[0036]

[Comparative Example 1] The properties of the film obtained in Example 2 before sandblasting were measured, and the specular gloss Gs was found.
(60 °) 115% and Y value was 1.6%. I also tried to draw a line on the surface of this film with a pencil of HB hardness, but I could not draw at all. The adhesive strength at that time was as low as 0.3 kg / cm.

[0037]

EFFECT OF THE INVENTION The film of the present invention has good mechanical properties represented by high strength and high Young's modulus, which are not found in commercially available films, as shown in Examples, and has excellent adhesiveness. Since the mirror surface glossiness is low, letters and pictures can be easily written on the film surface with a pencil, and it is a thin film that is flexible and easy to handle because it is flexible, and when used as a tracing paper, it can be used as a storage space. There is an effect that it can be reduced. Further, in addition to these properties, it has excellent electric insulation, heat resistance, oil resistance, pressure resistance, chemical resistance other than strong acid, and structural denseness. The film of the present invention can be suitably used as an insulating material for electric devices, a flexible printed wiring board, a heat-resistant barcode label, an electric wire coating material, a filtration membrane, and a plate-making material.

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Claims (3)

[Claims] 1. A film made of a linearly coordinated aromatic polyamide having an inherent viscosity of 3.5 or more, a Young's modulus in all directions of 800 Kg / mm ² or more, and a tensile elongation of 10 in all directions. %, And the specular gloss Gs (60 °) of the surface of the film is 20% or less. 2. An optically anisotropic dope consisting essentially of a linear coordinating aromatic polyamide having an inherent viscosity of 3.5 or more and sulfuric acid of 95% by weight or more, while maintaining the optical anisotropy while supporting the supporting surface. In the method for producing a film, which is cast on the above and is converted into an optically isotropic solution by moisture absorption and / or heating and then coagulated and washed with water, the weight ratio of the washed water to the linear coordination aromatic polyamide is 0.5. A method for producing a film, which comprises applying a satin surface to a wet film of 3.0 to 3.0 and then drying the film while limiting the shrinkage of the film. 3. A linearly coordinated aromatic polyamide film having an inherent viscosity of 3.5 or more and a maximum diameter of 0.05 to 0.7 mm.
A method for producing a film, which comprises spraying the sand.