JPH09241402A - Aromatic polyamide film or aromatic polyimide film - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide an aromatic polyamide film or an aromatic polyimide film having excellent running properties, surface uniformity, and abrasion resistance when processed or made into a product. SOLUTION: This is a composite oxide mainly composed of silicon, aluminum and at least one alkali metal, and the content of silicon (Si), aluminum (Al) and alkali metal (M) is represented by the formula (1). To 0.005 to 10% by weight of particles having a volume average particle diameter of 0.005 to 2 μm, which are composed of a compound satisfying (3) to (3). 10% by weight ≤ Si ≤ 45% by weight (1) 3% by weight ≤ Al ≤ 30% by weight (2) 0.5% by weight ≤ M ≤ 20% by weight (3)

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aromatic polyamide film or an aromatic polyimide film. More specifically, it relates to an aromatic polyamide film or an aromatic polyimide film having excellent wear resistance, surface uniformity, and running property.

[0002]

2. Description of the Related Art Aromatic polyamide films and aromatic polyimide films have been studied for various applications by utilizing their excellent heat resistance and mechanical properties. In particular, para-oriented aromatic polyamides are superior to other polymers in mechanical properties such as rigidity and strength, so they are very advantageous for thinning films, and can be used for printer ribbons, magnetic tapes, capacitors, etc. ing.

However, the aromatic polyamide film and the aromatic polyimide film have a problem that productivity is lowered due to insufficient running property when processed into a product.
As a method for improving such a problem, conventionally, a method of dispersing particles in a film to give unevenness to the surface of a molded article has been performed. Although this method is effective in solving the problem of running property, it cannot be said that the product has sufficient abrasion resistance and scratch resistance when it is used as a product.

For example, when the abrasion resistance of the film for magnetic tape is low, abrasion powder of the film is apt to be generated during the manufacturing process of the magnetic tape, resulting in coating omission in the step of applying the magnetic layer, resulting in magnetic recording. Causes dropouts, etc. In addition, when using a magnetic tape, in most cases, it is run while contacting with a recording / reproducing device, etc., so abrasion powder generated at the time of contact adheres to the magnetic body, and during recording / reproducing, dropout (drop / drop) of magnetic recording occurs. Out).

That is, the film for a magnetic tape is required to have running property and abrasion resistance both during the magnetic tape manufacturing process and when it is used as a magnetic tape.

In order to solve these problems, it has been known to improve the surface property by adding inorganic particles such as silica particles to the film, as disclosed in JP-A-60-127523.
JP-A No. 60-201914 and the like. Although a uniform surface is formed by these methods, it cannot be said that the magnetic recording medium, which has been used under severer environment in recent years, has sufficient running property and abrasion resistance.

Regarding the polyester film which has been widely used as a base material for magnetic recording media, a method of adding particles is described in, for example, JP-A-62-1720.
31 (silicone particles), JP-A-5-3377 (spherical silica and calcium carbonate), JP-A-5
-4412 (Spherical silica), JP-A-5-4413
Japanese Patent Publication (spherical silica) and the like. Although these particles are suitable for forming a uniform surface, they cannot be said to have a sufficiently high affinity with aromatic polyamide or aromatic polyimide, and often fall off to cause traps. In addition to these, JP-A-55-45118 (aluminum silicate), JP-A-55-107495 (aluminum silicate) and the like can be mentioned. However, in these, the shape of the particles is indefinite. However, there are many coarse particles in the particle size distribution, and the surface uniformity and wear resistance are still insufficient, and there is room for improvement.

[0008] Further, in recent years, as the use of films has become higher in quality, and the development of more functional films is desired,
Conventional films are not always sufficient in running property and abrasion resistance, and further improvement is required.

[0009]

The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, in which specific particles having a high affinity for aromatic polyamide or aromatic polyimide are treated with an aromatic polyamide film or an aromatic polyamide. It is intended to provide an aromatic polyamide film or an aromatic polyimide film which is excellent in running property, surface uniformity and abrasion resistance when processed or made into a product by being contained in the group polyimide film.

[0010]

In order to solve the above problems, the aromatic polyamide film or aromatic polyimide film of the present invention is a composite oxide containing silicon, aluminum and at least one alkali metal as main constituents. Yes, silicon (Si), aluminum (Al)
And the content of the alkali metal (M) is represented by the formulas (1) to (3).
Volume average particle diameter 0.005 to 2 μm of a compound satisfying
m particles in an amount of 0.005 to 10% by weight. 10% by weight ≤ Si ≤ 45% by weight (1) 3% by weight ≤ Al ≤ 30% by weight (2) 0.5% by weight ≤ M ≤ 20% by weight (3)

The aromatic polyamide of the present invention is preferably one containing 50 mol% or more of the repeating unit represented by the following general formula 1 and / or general formula 2, and 70 mol%
The above is more preferable.

[0012]

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[0013]

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Examples of Ar ₁ , Ar ₂ and Ar ₃ include those shown in Chemical formula ₃ , and X and Y are --O.
_{-, - CH 2 -, -} CO -, - SO 2 -, - S -, - C
It is selected from (CH ₃ ) ₂ − and the like, but is not limited thereto. Further, some of the hydrogen atoms on these aromatic rings are halogen groups such as fluorine, chlorine and bromine (especially chlorine), nitro groups, alkyl groups such as methyl, ethyl and propyl (especially methyl groups), methoxy, ethoxy, It also includes those substituted with a substituent such as an alkoxy group such as propoxy, and also includes those where the hydrogen in the amide bond constituting the polymer is replaced with another substituent.

[0015]

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From the viewpoint of characteristics, those in which the above-mentioned aromatic rings are bonded at the para-position account for at least 50%, preferably 75%, of the total aromatic rings.
% Of the polymer is preferable because the film has high rigidity and good heat resistance. If 30% or more of all aromatic rings have hydrogen atoms on the aromatic ring replaced by halogen groups (especially chlorine), moisture resistance is improved, and characteristics such as dimensional change and rigidity reduction due to moisture absorption are improved. Is preferred.

The aromatic polyamide of the present invention has the general formula 1
And / or containing 50 mol% or more of the repeating unit represented by the general formula 2, and less than 50 mol% may be copolymerized or blended with other repeating units.

The aromatic polyimide in the present invention is one having at least one aromatic ring and at least one imide ring in the repeating unit of the polymer, and has the general formula 4 and / or the general formula 5.
The content of the repeating unit represented by is 50 mol% or more, preferably 70 mol% or more.

[0019]

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[0020]

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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. As a typical example, the one shown in Chemical formula 6 below can be given.

[0022]

[Chemical 6]

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 acid anhydride or its halide. Ar ₅ and Ar ₇ are, for example,
And X and Y are -O- and -C.
_{H 2 -, - CO -,} - SO 2 -, - S -, - C (C
H ₃ ) ₂ − and the like, but not limited thereto. Furthermore, some of the hydrogen atoms on these aromatic rings are
Substituted with a substituent such as a halogen group (especially chlorine) such as fluorine, chlorine and bromine, a nitro group, an alkyl group (especially a methyl group) such as methyl, ethyl and propyl, and an alkoxy group such as methoxy, ethoxy and propoxy. Including things.

[0025]

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The aromatic polyimide of the present invention has the general formula 4
And / or the repeating unit represented by the general formula 5 is contained in an amount of 50 mol% or more, and less than 50 mol% may be copolymerized or blended with other repeating units.

The composition of the particles composed of the composite oxide in the present invention (hereinafter referred to as composite oxide particles) has a composition of silicon atom (Si), aluminum atom (Al) and alkali metal atom (M) of 10% by weight, respectively. % ≤Si≤45% by weight (1) 3% by weight≤Al≤30% by weight (2) 0.5% by weight≤M≤20% by weight (3) When the composition is within the above range, the affinity with the aromatic polyamide or the aromatic polyimide is high, particles are less likely to fall off during film production and product processing, and excellent running property is obtained.

Preferably, 15% by weight≤Si≤40% by weight 5% by weight≤Al≤25% by weight 0.5% by weight≤M≤15% by weight, more preferably 15% by weight≤Si≤35% by weight % 5% by weight ≦ Al ≦ 25% by weight 1% by weight ≦ M ≦ 15% by weight.

The molar ratio of aluminum to alkali metal at this time is preferably 0.8≤Al / M≤1.2 (4) from the viewpoint of thermal stability. Furthermore, particle size distribution control of particles,
From the viewpoint of particle size control and the like, the alkali metal is more preferably sodium.

The water content in such composite oxide particles is preferably 0.1% by weight ≦ H ₂ O ≦ 20% by weight (5) from the viewpoint of dispersion stability of the particles. , And more preferably 1% by weight ≦ H ₂ O ≦ 20% by weight. However, the water content here is 1
It is the water content that evaporates when the temperature is raised to 300 ° C. at a rate of 0 ° C./min.

The volume average particle diameter is preferably 0.005 to 2 μm, and more preferably 0.01 to 1 μm from the viewpoint of running stability and abrasion resistance. The relative standard deviation σ of the particle size distribution at this time is preferably 0.5 or less, more preferably 0.3 or less, and particularly preferably 0.15 or less from the viewpoint of surface uniformity, abrasion resistance and the like. Is preferred. When the volume average particle size of the particles exceeds 2 μm,
The surface protrusions become too large, and they easily fall off while driving,
If it is smaller than 0.005 μm, sufficient projections cannot be obtained, and the running property is deteriorated, which is not preferable.

The content of the composite oxide particles in the aromatic polyamide or the aromatic polyimide is 0.005-10.
%, And more preferably 0.01 to 3% by weight from the viewpoint of running stability and surface uniformity. When the content is less than 0.005% by weight, abrasion resistance is not sufficiently expressed, and when the content is more than 10% by weight, agglomeration of particles occurs to form coarse particles and the surface of the film. It is not preferable because it may significantly reduce the roughness.

Further, the composite oxide particles in the present invention are
It can be manufactured by the following methods. For example, p
Target particles can be produced by simultaneously adding an alkali metal, ammonium or organic base silicate and an alkali-soluble aluminum compound to an alkali aqueous solution of H10 or more and reacting them. At this time, in order to generate particles having a larger specific surface area, the reaction solution is adjusted to have a silicon atom / aluminum atom molar ratio of 0.
It is preferable to use a method of adjusting so as to be 25 to 10.

Further, the particles may be multi-layered particles having the composite oxide in the outermost layer. In this case, for example, when the reaction is carried out after dispersing the seed particles in an alkaline aqueous solution having a pH of 10 or more, the particles grow with the seed particles as nuclei, so that the particle size and the particle size distribution are controlled. Can be facilitated. In this case, the seed particles have a relative standard deviation σ of 0.5 or less and a major axis / minor axis ratio of the particles of 1 to 1 from the viewpoint of controlling the particle size distribution of the composite oxide particles and controlling the particle morphology. It is preferably 1.2. The type of seed particles is not particularly limited, for example, silica, alumina, zirconia,
Titanium oxide, tin oxide, antimony oxide, yttrium oxide, cerium oxide, indium oxide, iron oxide and the like can be used. In particular, silica particles are preferably used because the growth reaction of the particles can be easily controlled. You can

Further, the thickness of the composite oxide layer at this time is set to 0.01 to 0.3 μm so that the abrasion resistance, the particle strength, the surface protrusion strength, and the affinity with the aromatic polyamide or the aromatic polyimide can be obtained. It is preferable in terms of properties and the like, more preferably 0.05 to 0.2 μm, and particularly preferably 0.08 to 0.2 μm.

The specific surface area is preferably in the range that satisfies the following formula, from the viewpoint of affinity with aromatic polyamide or aromatic polyimide, and particularly preferably porous. S ≧ 3.5 / Dw However, Dw: volume average particle diameter (μm) S: specific surface area (m ² / g).

Further, as the strength of the composite oxide particles, anti the strength when deformed the particles _10% (S 10) satisfies the relationship of _{^{5kgf / mm 2 ≦ S 10 ≦}} 40kgf / mm 2 It is preferable from the viewpoints of abrasion resistance and strength of surface protrusions, and more preferably 10 kgf / mm ²
≦ S ₁₀ ≦ 25 kgf / mm ² .

Such composite oxide particles can be surface-treated within a range that does not impair the effects of the present invention. Examples of the surface treatment agent include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium dialkylsulfosuccinate, and formalin condensate salt of naphthalenesulfonic acid, polyoxynonylphenol ether, polyethylene glycol monostearate. Rate, nonionic surfactants such as sorbitan monostearate, polyvinyl alcohol,
Water-soluble synthetic polymers such as polyvinylpyrrolidone and polyethylene glycol, water-soluble natural polymers such as gelatin and starch, water-soluble semi-synthetic polymers such as carboxymethylcellulose, silane-based and titanium-based coupling agents, phosphoric acid , Phosphorus compounds such as phosphorous acid, phosphonic acid and their derivatives can be used.

Further, in order not to impair the effects of the present invention, other compounds such as waxes, modifiers and flame retardants are added in order to improve functionality such as moldability, transparency and electrostatic castability. It doesn't matter.

The composite oxide particles in the present invention are preferably amorphous in terms of affinity with polymers, hardness, surface morphology of particles, surface reactivity and the like.

Furthermore, within the range that does not impair the effects of the present invention, the following particles (A) other than the composite oxide particles,
And the particles (B) can be used in combination. The particles (A) at this time have a volume average particle diameter of 0.005 to 1 μm.
Particles of m are preferable from the viewpoint of wear resistance, running stability, surface uniformity, and the like, and more preferably 0.01 to 0.5 μm. Further, the particles (A) have wear resistance,
0.1 μm more than composite oxide particles in terms of surface uniformity
It is preferably smaller than the above. The content of the particles (A) is 0. with respect to the aromatic polyamide or the aromatic polyimide.
The content is preferably 005 to 3% by weight from the viewpoint of wear resistance and surface uniformity, and more preferably 0.01 to 2% by weight. Examples of such particles (A) include,
Examples thereof include silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, spinel and iron oxide. Among these particles, zirconium oxide, aluminum oxide affinity with aromatic polyamide or aromatic polyimide,
It is particularly preferable in terms of abrasion resistance, dispersion stability and the like.

On the other hand, the particles (B) preferably have a volume average particle diameter of 0.05 to 2 μm from the viewpoint of running stability and surface uniformity. Further, the difference in volume average particle size between the particles (B) and the composite oxide particles is preferably 0.1 μm or more from the viewpoint of running stability and surface uniformity. The content of the particles (B) is preferably 0.005 to 0.3% by weight from the viewpoint of running stability and surface uniformity.
Examples of such particles (B) include inorganic particles such as talc, calcium sulfate, barium sulfate, calcium carbonate, and zinc sulfide. Among them, calcium carbonate has an affinity with aromatic polyamide or aromatic polyimide. From the viewpoints of surface uniformity, dispersion stability, etc., it is particularly preferable. In addition to such inorganic particles, crosslinked organic polymer particles can also be used.

Various materials such as polymethylmethacrylate, formaldehyde resin, phenol resin, crosslinked polystyrene, silicone resin, fluororesin, polyamide resin and polyimide resin can be used as the material of such particles.

Here, the organic polymer particles have a thermal decomposition temperature (10% reduction temperature, nitrogen flow, temperature rising rate 10
Particles having heat resistance of (° C / min) of 350 ° C or higher do not easily agglomerate during the production of the aromatic polyamide film or the aromatic polyimide film or the reuse and recovery of the film, and thus the surface uniformity and abrasion resistance of the film. And the like are preferable, and more preferably 360 ° C. or higher, particularly preferably 370 ° C. or higher. Such organic polymer particles have a degree of cross-linking defined by the following formula: cross-linking degree = weight of cross-linking component of raw material monomer / total weight of raw material monomer × 100 (%), based on all organic components constituting the particle. When it is above, the dispersibility of the particles becomes good when it is made into an aromatic polyamide or aromatic polyimide film, and it is preferable, and it is more preferably 30% or more, particularly preferably 55% or more.

Further, such organic polymer particles have strength (S ₁₀ ) when deformed by 10%, satisfying a relationship of 0.5 kgf / mm ² ≤S ₁₀ ≤15 kgf / mm ^2. but running stability, abrasion resistance, strength of surface protrusions, preferably in terms of such dimensional stability, more preferably _{^{0.5kgf / mm 2 ≦ S 10 ≦}} 13kgf / mm 2.

The method for incorporating the composite oxide particles in the present invention into the aromatic polyamide or the aromatic polyimide is in the form of a slurry in advance in an organic solvent of 10 poise or less or the aromatic polyamide, the aromatic polyimide or the polyamic acid solution. A method of mixing and dispersing, or a method of drying the particles and adding the particles to a polymer before being subjected to film formation and kneading can be employed. In the former case, the timing of addition may be before polymerization, during polymerization, or after completion of polymerization.

The aromatic polyamide polymer or the aromatic polyimide composition polymer thus obtained may be other aromatic polyamide or aromatic polyimide composition such as diluting aromatic polyamide or aromatic polyimide depending on the purpose. It may be used by blending with.

The aromatic polyamide film or aromatic polyimide film of the present invention can be produced, for example, by the following method, but the invention is not limited thereto.

First, an aromatic polyamide, but when it is obtained from an acid chloride and a diamine, it is used in an aprotic organic polar solvent such as N-methylpyrrolidone (NMP), dimethylacetamide (DMAC) or dimethylformamide (DMF). , Solution polymerization or interfacial polymerization using an aqueous medium. When acid chloride and diamine are used as monomers in a polymer solution, hydrogen chloride is by-produced.When neutralizing this, an inorganic neutralizing agent such as calcium hydroxide, calcium carbonate, lithium carbonate, or ethylene is used. Oxide, propylene oxide, ammonia,
Organic neutralizers such as triethylamine, triethanolamine, diethanolamine, etc. are used. The reaction between the isocyanate and the carboxylic acid is performed in an aprotic organic polar solvent in the presence of a catalyst.

These polymer solutions may be used as a stock solution for film formation as they are, 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. Good.

In order to obtain the aromatic polyamide film of the present invention, the intrinsic viscosity of the polymer (value measured at 30 ° C. in a solution of 0.5 g of polymer in 100 ml of sulfuric acid) is 0.
It is preferably 5 or more.

Inorganic salts such as calcium chloride, magnesium chloride, lithium chloride and lithium nitrate may be added as a dissolution aid to the stock solution for film formation. The polymer concentration in the stock solution is preferably about 2 to 40% by weight.

The particles can be added by a method in which the particles are sufficiently slurried in a solvent in advance and then used as a solvent for polymerization or a solvent for dilution, or a method of directly adding after preparing a film-forming stock solution.

The film-forming stock solution prepared as described above is filtered by a filter having a filtration accuracy of 6000 nm or less, and then formed into a film by a so-called solution film-forming method. The solution casting method includes a dry-wet method, a dry method, and a wet method. When a film is formed by a wet method, the stock solution is filtered and then extruded directly from a die into a film forming bath, or once extruded onto a support such as a drum or a belt and then introduced into the wet bath together with the support. Is adopted. This bath is generally composed of an aqueous medium, and may contain an organic or inorganic solvent or an inorganic salt in addition to water. The bath temperature is usually from 0 to 100 ° C., and salts and solvents contained in the film are extracted by passing through a wet bath. Here, the film when introduced into the wet bath does not yet have a sufficient surface hardness, so if there is contamination or the like in the wet bath medium, the film surface adheres and the surface properties deteriorate. Therefore, the medium used in the wet bath should have a filtration accuracy of 6000 nm or less, preferably 50
It should be supplied through a filter having a size of 00 nm or less, more preferably 3000 nm or less. The time required to pass through these wet baths is 10 seconds to 30 minutes, depending on the thickness of the film. Further, if necessary, the film is stretched in the longitudinal direction. Next, drying and heat treatment are performed. These treatments are generally performed at 200 to 500 ° C. for a total of 1
The heating is preferably performed for 2 seconds to 30 minutes, more preferably at or below the heat resistant temperature of the organic particles. In this process, transverse stretching is performed as necessary.

When a film is formed by a dry-wet method, the stock solution is extruded from a spinneret onto a support such as a drum or an endless belt to form a thin film, and then the solvent is scattered from the thin film layer until the thin film has a self-holding property. To do. Drying conditions are from room temperature to 2
20 ° C., within 60 minutes, preferably from room temperature to 2
It is in the range of 00 ° C. If the drying temperature is higher than 220 ° C., the surface may be rough due to abrupt desolvation, particles may easily fall off, and the surface uniformity may be deteriorated due to a sudden increase in average roughness or an increase in the number of coarse projections. Further, by controlling the frequency of surface defects of the drum and the endless belt used in this drying step, the surface property of the surface in contact with the support can be controlled within a range useful as a base film of a magnetic recording medium.
The frequency of surface defects having a diameter of 30 μm or more is preferably 0.00
1-0.02 pieces / mm ² , more preferably 0.002-
It is 0.015 pieces / mm ² . After the dry process, the film is peeled from the support, introduced into the wet process, subjected to desalting and solvent removal in the same manner as in the above wet process, and further stretched, dried and heat-treated to form a film.

When the dry process is adopted, the film which is dried on a drum, an endless belt or the like and has a self-holding property is peeled from these supports and stretched in the longitudinal direction of the film. . Further drying, stretching, and heat treatment for removing the residual solvent are performed. These treatments are preferably performed at 200 to 500 ° C. for 1 second to 30 minutes, but are performed at a temperature equal to or lower than the heat resistant temperature of the organic particles. Is more preferred.

The film formed as described above is stretched in the film forming process so that the mechanical properties and the thermal properties are within the range of the present invention.
The area ratio is preferably 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 relaxing. More preferably, it is 1.1. ~ 5.

The film obtained from the aromatic polyamide or aromatic polyimide of the present invention is a single layer film,
It is also used as a laminated film. In the case of a laminated film, it is preferable to use the film of the present invention as a film constituting at least one layer because the abrasion resistance and the running property of the film surface will be good. Further, from the viewpoint of running property and dubbing property, the film containing aluminum silicate is preferably one of the outermost layers of the laminated film. These laminating methods include well-known methods, for example,
There are a method of laminating in a die, a method of laminating in a composite pipe, and a method of forming one layer once and forming another layer thereon.

For example, when the composite oxide particles and the above-mentioned particles (A) other than the composite oxide particles are used in combination, the respective particles may be contained in different layers. From the viewpoint, it is preferable that the composite oxide particles and the particles (A) are contained in the same outermost layer on at least one side, and the thickness t of the film layer containing the composite oxide particles at this time is t.
From the viewpoint of runnability, surface uniformity, etc., the relationship with the average particle size d of the composite oxide particles is preferably 0.2d ≦ t ≦ 20d, more preferably 0.5d ≦ t ≦ 10.
d, particularly preferably 0.5d ≦ t ≦ 3d.

Further, when the composite oxide particles and the particles (A) are contained in different layers, the thickness t of the film layer containing the composite oxide particles is, in view of running property, surface uniformity and the like. The relationship with the particle size d of the composite oxide particles is 0.2d ≦
t ≦ 20d is preferable, and more preferably 0.
It is preferable that 5d ≦ t ≦ 10d, particularly 0.5d ≦ t ≦ 3d. Further, from the viewpoint of running quality, abrasion resistance, dapping property, etc., it is preferable that the layer containing the particles (A) is present as the outermost layer outside the film layer containing the composite oxide particles. The thickness of the outermost layer is 0.005 to 1 from the viewpoint of wear resistance, running property, surface uniformity, etc.
μm is preferable, and more preferably 0.01 to
It is preferably 0.5 μm, particularly preferably 0.02 to 0.3 μm.

From the viewpoint of abrasion resistance, running property, etc., this film has a number of projections on at least one side of 2 × 10 ³ to.
It is preferably 5 × 10 ⁷ pieces / mm ² , more preferably 5 × 10 ^{3 to} 5 × 10 ⁶ pieces / mm ² , and particularly 1 × 10 ⁴ to 1 × 10 ⁶ pieces / mm ² . It is preferable.

[0062]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. (A) Particle characteristics (1) Particle size ratio, average particle size, measurement of particle size distribution and calculation of relative standard deviation σ An aromatic polyamide film or an aromatic polyimide film containing particles is cut into an ultrathin section having a thickness of 0.2 μm. After cutting into pieces, at least 100 with a transmission electron microscope.
Each particle was observed and measured. The formulas for calculating the relative standard deviation σ and the average particle diameter are as shown in the following formula 2.

[0063]

[Equation 2]

[Mathematical formula-see original document] Here, in the equation 2, D: number average particle diameter (μm) Di: particle diameter (μm) n: number of particles (pieces)

(2) Quantification of Alkali Metal Atom The measurement was carried out by the atomic absorption method.

(3) Quantification of silicon atom and aluminum atom Measurement was carried out by a fluorescent X-ray analysis method.

(4) Analysis of crystal structure Analysis was performed by the X-ray diffraction method.

(5) Thermal Decomposition Temperature of Particles A thermobalance weight loss curve was measured at a temperature rising rate of 20 ° C./minute under a nitrogen atmosphere with TAS-100 manufactured by Rigaku Denki Co., and 10% weight loss temperature was defined as the thermal decomposition temperature. did.

(6) Measurement of particle strength (S ₁₀ ) A micro compression tester (MCTM-20 manufactured by Shimadzu Corporation)
Load speed: 0.0145 gf / s
The amount of deformation was measured by applying a load of 0 to 1 gf. This measurement was performed 10 times, and S ₁₀ was calculated according to the following formula from the average value of the load P (kgf) when the particles were 10% deformed. S ₁₀ = 2.8 P / πd ² where, P: average value of load when particles are deformed by 10% (kg
f) d: Volume average particle diameter (mm).

(6) Measurement of Water The composite oxide particles were thoroughly washed with methanol, and then vacuum-dried at room temperature for about 1 day with a vacuum dryer, and then with a TAS-100 manufactured by Rigaku Denki Co., under a nitrogen atmosphere. The water content that evaporated when the temperature was raised to 300 ° C. was measured at a heating rate of 10 ° C./min.

(B) Film Properties (1) Surface Roughness Ra (μm) The surface roughness Ra (μm) was measured using a high precision thin film step measuring instrument ET-10 manufactured by Kosaka Laboratory. The conditions were as follows, and the value was determined as the average value of 20 measurements.・ Stylus tip radius: 0.5 μm ・ Stylus load: 5 mg ・ Measurement length: 1 mm ・ Cutoff value: 0.08 mm Ra is defined, for example, by Jiro Nara, "Measurement / Evaluation Method of Surface Roughness" ( General Technology Center, 1983).

(2) Abrasion resistance A tape-shaped roll in which a film is narrowly slit is rubbed against a guide roll made of stainless steel SUS-304 at a constant tension at high speed for a long time, and depending on the amount of white powder generated on the guide roll surface, Ranked as. Class A: No white powder is generated B Class: White powder is slightly generated C Class: White powder is slightly large D Class: White powder is large

(3) Runnability (friction coefficient μk) A tape runnability tester SFT-700 type (manufactured by Yokohama System Laboratory Co., Ltd.) was used by slitting a film into a tape having a width of 1/2 inte. The film was run in an atmosphere of 20 ° C. and 60% RH, and the initial friction coefficient was determined by the following formula (film width was 1/2 inch). μk = 2 / πln (T2 / T1) where T1 is the entrance tension and T2 is the exit tension. The guide diameter is 6 mmφ, the guide material is SUS27 (surface roughness 0.2S), the winding angle is 90 °, and the running speed is 3.
It is 3 cm / sec. When μk obtained by this measurement was 0.3 or less, it was determined that the friction coefficient was good, and when it was more than 0.3, the friction coefficient was poor.

(4) Number of protrusions on film surface Primitive force microscope (Nanoscop manufactured by Digital Instruments)
Using eII), when the height of the flat surface of the film is 0, the number of protrusions on the surface having a height from the flat surface of 30 nm is determined. This measurement was repeated 5 times at different places, and the average number was determined as the number of protrusions. In some cases, a high-precision optical interference type three-dimensional surface analyzer (WY
KO TOPO-3D, objective lens: 40-200
The height information obtained by using the optical resolution camera can be used instead of the SEM value.

Example 1 Volume average particle diameter of 0.30 μm, S ₁₀ of 21 kgf / mm ²
10 parts by weight of composite oxide particles, N-methyl-2-
90 parts by weight of pyrrolidone (hereinafter abbreviated as NMP) was mixed and stirred with a dissolver at room temperature for 2 hours to obtain NMP slurry (A) of composite oxide particles.

Volume average particle diameter 0.10 μm, specific surface area 2
10 parts by weight of alumina particles that are 00 m ² / g, NMP
90 parts by weight was stirred with a dissolver at room temperature for 2 hours to obtain an NMP slurry (B) of alumina particles.

10 parts by weight of styrene-divinylbenzene copolymer particles having a volume average particle size of 0.6 μm, a degree of crosslinking of 80% by weight, a thermal decomposition temperature of 390 ° C. and an S ₁₀ of 6 kgf / mm ² and 90 parts by weight of NMP were used. The mixture was stirred at room temperature for 2 hours with a dissolver to obtain a styrene-divinylbenzene copolymer slurry (C).

On the other hand, 2-chloroparaphenylenediamine corresponding to 80 mol% as an aromatic diamine component and 4,4-diaminodiphenyl ether corresponding to 20 mol% were dissolved in N-methylpyrrolidone (NMP). Then, 2-chloroterephthalic acid chloride corresponding to 100 mol% was added thereto and stirred for 2 hours to complete the polymerization. After neutralizing this with lithium hydroxide, (A), (B),
The slurry of (C) was added so that the content in the film would be the amount shown in Table 1 to obtain an aromatic polyamide solution having a polymer concentration of 10% by weight and a viscosity of 3000 poise.

After passing this polymer solution through a filter having a filtration accuracy of 5000 nm, the polymer solution was cast onto a belt having a frequency of surface defects of 30 μm or more and 0.005 defects / mm ² , and
The solvent was evaporated by heating for 2 minutes with hot air of 0 ° C., and the self-supporting film was continuously peeled off from the belt. Next, NMP filtered with a filter with a filtration accuracy of 4000 nm
The water is extracted from the residual solvent and the inorganic salt produced by neutralization by introducing the film into a water tank with a concentration gradient using water and water.
4.5μ thickness after drying and heat treatment with a tenter
m was obtained. During this period, the film was stretched 1.2 times and 1.3 times in the width direction, respectively, dried at 280 ° C. for 1.5 minutes and heat-treated, and then slowly cooled at a rate of 20 ° C./sec to give aromatics. A polyamide film was obtained.

When this film was evaluated, Ra =
The film was 0.015 μm, the coefficient of friction μk = 0.11 and the abrasion resistance evaluation was class A, and the abrasion resistance and running property were very excellent. The volume average particle diameter of the composite oxide particles measured by a transmission electron microscope was 0.30 μm, the ratio of major axis / minor axis of the particles was 1.05, and the relative standard deviation σ was 0.11. The volume average particle diameter of the alumina particles was 0.10 μm, and the volume average particle diameter of the styrene-divinylbenzene copolymer particles was 0.45 μm. The results are shown in Table 1.

Examples 2 to 8 A biaxially stretched aromatic polyamide or aromatic polyimide film was prepared in the same manner as in Example 1, except that the type of particles in the aromatic polyamide, the average particle size, the amount of particles added, etc. were changed. Obtained. Table 1 shows the evaluation results of these films. It can be seen that these films have good wear resistance and runnability.

Example 9 An aromatic polyamide polymer (P) was prepared in the same manner as in Example 1 except that only two kinds of particles, the composite oxide particles shown in Table 1 and a styrene-divinylbenzene copolymer were added as particles.
I got An aromatic polyamide polymer (Q) was obtained in the same manner as in Example 1 except that only alumina shown in Table 1 was added as particles. A laminated aromatic polyamide film was obtained in the same manner as in Example 1 except that these (P) and (Q) were combined using a laminated tube and discharged from the mouthpiece onto the belt.
The thickness of each layer of (P) and (Q) is 1.3 μm,
It was 1.2 μm. When this film was evaluated,
As shown in Table 1, Ra = 0.09 μm, abrasion resistance evaluation class A, friction coefficient μk = 0.13, and the film was excellent in abrasion resistance and running property.

Example 10 A polymer (R) containing no particles added to the polymer prepared in Example 1 was prepared. On the other hand, a polymer (S) containing the same particles as in Example 1 was prepared and S / R /
A three-layer composite aromatic polyamide film of S was obtained according to Example 1. The thickness of each layer is S / R / S = 1.1 / 1.8.
It was /1.1 (micrometer). When this film was evaluated, as shown in Table 1, it was Ra = 0.012 μm, abrasion resistance evaluation class A, friction coefficient μk = 0.12, and was a film excellent in abrasion resistance and running property.

Example 11 Paraphenylenediamine corresponding to 100 mol% as an aromatic diamine component was dissolved in NMP, and 100% of this was dissolved.
A polyamic acid solution was obtained by adding and polymerizing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride corresponding to mol%. In this solution, particle slurry (A), (B),
(C) was added as shown in Table 2 to obtain a polymer solution having a polymer concentration of 15% by weight and a solution viscosity of 3400 poise. After passing this polymer solution through a filter with a filtration accuracy of 5000 nm, the frequency of surface defects with a diameter of 30 μm or more was 0.005.
The film was cast onto a belt having a number of pieces / mm ² and heated with hot air at 150 ° C. for 2 minutes to evaporate the solvent, and the film having self-holding property was continuously peeled from the belt. Next, after heat-treating for 3 minutes with a tenter at 360 ° C., it was gradually cooled at a rate of 20 ° C./sec to obtain an aromatic polyimide film. Draw ratio is M
Both D and TD were 1.1 times and the thickness was 6 μm. When this film was evaluated, as shown in Table 1, Ra =
0.015 μm, abrasion resistance evaluation class A, friction coefficient μk =
The value was 0.12, and the film was excellent in abrasion resistance and runnability.

Comparative Examples 1 and 2 An aromatic polyamide film was obtained in the same manner as in Example 1, except that the kind of particles, the average particle size and the particle content were changed. Table 2 shows the evaluation results of these films. These films were not films having satisfactory wear resistance and running properties.

Comparative Example 3 Example 1 was carried out by using kaolin instead of the composite oxide particles.
A biaxially stretched film was obtained in the same manner as in. Table 2 shows the evaluation results of these films. These films are
The film was not satisfactory in both abrasion resistance and running performance.

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[Table 1]

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[Table 2]

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INDUSTRIAL APPLICABILITY According to the present invention, by using specific particles in the aromatic polyamide or aromatic polyimide film, it is possible to obtain a film excellent in running property and abrasion resistance. The film of the present invention is preferably used for magnetic recording media, electric printed circuits such as flexible printed circuits, TAB and capacitors, and thermal recording applications by utilizing its excellent characteristics. It can be preferably used for an external memory for computers such as DDS-2, 3, 4, QIC, data 8 mm and the like, and a tape for digital video which require high density and high accuracy.

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Claims (14)

[Claims] 1. A composite oxide mainly composed of silicon, aluminum and at least one alkali metal, wherein the contents of silicon (Si), aluminum (Al) and alkali metal (M) are represented by the formula (1) ) To (3), the aromatic polyamide film or aromatic polyimide film is characterized by containing 0.005 to 10% by weight of particles having a volume average particle diameter of 0.005 to 2 μm. 10% by weight ≤ Si ≤ 45% by weight (1) 3% by weight ≤ Al ≤ 30% by weight (2) 0.5% by weight ≤ M ≤ 20% by weight (3) 2. The aromatic polyamide film or aromatic polyimide film according to claim 1, wherein the particles of the composite oxide are substantially amorphous. 3. The aromatic polyamide film according to claim 1, wherein the molar ratio (Al / M) of aluminum (Al) and alkali metal (M) is in the range satisfying the formula (4). Or an aromatic polyimide film. 0.8 ≦ Al / M ≦ 1.2 (4) 4. The aromatic polyamide film or aromatic polyimide film according to claim 1, wherein the alkali metal is sodium. 5. The aromatic polyamide film or aromatic polyimide film according to claim 1, wherein the particles of the composite oxide have a water content satisfying the formula (5). 0.1% by weight ≤ H ₂ O ≤ 20% by weight (5) 6. The relative standard deviation σ shown in the following formula 1 of the particle size distribution of the particles made of the composite oxide is 0.5 or less,
The aromatic polyamide film or aromatic polyimide film according to any one of claims 1 to 5, wherein the ratio of major axis / minor axis of particles is 1 to 1.2. [Equation 1] However, D: number average particle diameter (μm) Di: particle diameter (μm) n: number of particles (pieces). 7. The aromatic polyamide film or aromatic polyimide film according to claim 1, wherein the contained particles are multi-layered particles having a composite oxide in the outermost layer. 8. The volume average particle diameter Dw (μm) and the specific surface area S (m ² / g) of the composite oxide particles are S ≧ 3.5.
The aromatic polyamide film or aromatic polyimide film according to any one of claims 1 to 7, which satisfies the relationship of / Dw. 9. A particle comprising a composite oxide comprises 1
Intensity when deformed 0% (S _{10) ^{is, 5kgf / mm 2 ≦ S 10}} ≦ 40kgf / mm claims 1, characterized by satisfying the ^two relationships to aromatic polyamide according to any one of the 8 Film or aromatic polyimide film. 10. The volume average particle diameter is 0.005 to 1 μm.
And the volume average particle size of the composite oxide particles is 0.1
smaller than μm and a specific surface area of 10 m ² / g or more,
The aromatic polyamide film according to any one of claims 1 to 9, which contains 0.005 to 3% by weight of particles (A) other than particles of the composite oxide having a Mohs hardness of 5 or more. Or an aromatic polyimide film. 11. A volume average particle diameter of 0.05 to 2 μm,
The difference in volume average particle size from the particles made of complex oxide is 0.1
The particles (B) other than the particles made of the composite oxide, which have a Mohs hardness of less than 4 and are not less than 0.005
The aromatic polyamide film or aromatic polyimide film according to claim 1, which contains 0.3% by weight. 12. A particle diameter d of particles comprising a composite oxide,
Thickness t of the film layer containing particles of a complex oxide
12. The aromatic polyamide film or aromatic polyimide film according to any one of claims 1 to 11, characterized in that 0.2d ≦ t ≦ 20d (6) 13. An aromatic polyamide film or an aromatic polyimide film in the form of a laminated film, wherein the film according to any one of claims 1 to 12 forms at least one outermost layer. 14. The number of protrusions on the film surface is 2 × 10 ^3.
The aromatic polyamide film or aromatic polyimide film according to any one of claims 1 to 13, wherein the aromatic polyamide film or the aromatic polyimide film has a density of 5 x 10 ⁷ pieces / mm ² .