JPH0696646B2 - Biaxially oriented polyetheretherketone film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a biaxially oriented polyetheretherketone film, and more specifically, it contains fine particles of silicone resin and has a flat surface, slipperiness, running durability, and insulation properties. Excellent characteristics,
The present invention also relates to a biaxially oriented polyetheretherketone film having excellent heat resistance.

[Prior Art] Conventionally, a biaxially oriented polyethylene terephthalate film has been widely used for industrial applications because of its excellent mechanical properties, electrical properties, heat resistance, chemical resistance and the like.

However, in recent years, the required properties of the film have been increased depending on the application, and the properties of the biaxially oriented polyethylene terephthalate film are also limited. Therefore, a film having more excellent properties is required. For example, biaxially oriented polyethylene terephthalate film has long-term heat resistance of Class E (long-term heat resistance temperature: 125 ° C) to Class B (the same: 130 ° C), and when used as a material for motor insulation and wire breakage coating, this long-term heat resistance From this point, there is a problem that miniaturization of the motor is limited. Further, when the above film is used for a capacitor, the dielectric loss tangent increases from around 85 ° C., which limits the operating temperature. Furthermore, when the above film is used as a flexible printed circuit board, solder heat resistance becomes a problem, and its development is limited. Therefore, there is a demand for a film having more excellent heat resistance.

By the way, a thermoplastic polyetheretherketone is known as a crystalline thermoplastic polymer which is tough and has excellent heat resistance (Japanese Patent Publication No. 60-32642, Japanese Patent Publication No. 61-10486),
Studies and proposals for making this film have been made. For example, in Japanese Patent Laid-Open No. 57-137116, thermoplastic polyetheretherketone films are used in fields of application utilizing heat resistance, that is, insulating films for motors, insulating films for transformers, insulating films for capacitors, flexible printed circuit boards, etc. A method for producing a uniaxially oriented film by a rolling method is described as expected to be applied to the above, and depending on the application, calcium carbonate, fine particle silicate, talc, basic magnesium carbonate, alumina, hydrated alumina. It is described that an inorganic filler such as a substance, barium sulfate, calcium sulfate, mica powder, zinc white, titanium oxide or carbon black may be added.

JP-A-58-63417 describes a method for producing an isotropic biaxially oriented polyetheretherketone film.

JP-A-60-93625 discloses a polyetheretherketone film for perpendicular magnetization which is biaxially oriented by a rolling method.

JP-A-60-187928 discloses that the stress at 5% elongation in the longitudinal direction and the direction perpendicular thereto is 13 kg / mm ² or more, and the initial elastic modulus in at least one direction is 600 kg / mm ² or more, and 180 A magnetic recording material based on a biaxially oriented polyetherketone (or polyetheretherketone) film having a thermal shrinkage of 4% or less in the lengthwise direction and the direction perpendicular thereto at 0 ° C is described, and titanium dioxide in a polymer is described. It is described that a lubricant such as a matting agent, fine particle silica, and China clay may be contained.

Japanese Unexamined Patent Publication No. 60-189421 discloses an inorganic particle-containing polyetherketone (or polyetheretherketone) having a surface roughness Ra of 0.008 to 0.090 and a dynamic friction coefficient μd.
A biaxially oriented film having a thickness of 0.12 to 0.50 is described, and as the inorganic particles, magnesium oxide, zinc oxide, magnesium carbonate, magnesium phosphate, calcium sulfate, barium sulfate, aluminum oxide, silicon dioxide, titanium oxide,
It is described that examples thereof include inorganic oxides such as kaolin and diatomaceous earth, inorganic salts, aluminosilicates and carbon black.

JP-A-61-37418 discloses a slippery thermoplastic polyetheretherketone in which a composition prepared by mixing 0.01 to 10 parts by weight of an inorganic filler with 100 parts by weight of polyetheretherketone is biaxially oriented. A film is described, and as this inorganic filler, one kind or two or more kinds of talc, silica, kaolin, calcined kaolin, mica, aerosil, siloid, calcium carbonate, potassium titanate fiber, etc. are appropriately selected and used, but particularly average It is described that fine particles having a particle diameter of 5 μ or less are preferable.

However, according to the research results of the present inventors, in these biaxially oriented polyetheretherketone films, voids are generated around the inorganic particles in the film, and the running durability, the insulation defect abnormality rate, and the dielectric breakdown occur. It became clear that there are issues that need to be improved, such as the rate. It was also found that the inorganic particles were poorly dispersed in the film.

[Object of the Invention] An object of the present invention is to provide a biaxially oriented polyetheretherketone film which has a flat surface and is excellent in slipperiness, running durability, insulation properties and the like, and is also excellent in heat resistance.

Another object of the present invention is to provide a biaxially oriented polyether ether having a large number of fine projections derived from silicon resin fine particles on the surface of the film and having a flat surface and excellent in slipperiness, running durability, insulation properties and the like. To provide a ketone film.

Further objects and advantages of the present invention will be apparent from the following description.

Structure / Effects of the Invention] According to the present invention, firstly, the above objects and advantages of the present invention are (I) a thermoplastic polyether ether ketone, and (II) (a) the following formula (A) RxSiO ₂ -x / 2 (A) Here, R is a hydrocarbon group having 1 to 7 carbon atoms, and x is a number of 1 to 1.2. (B) The following formula (B) f = V / D ³ (B) where V is the average volume per particle (μm ³ ) and D is the average maximum particle size (μm) of the particles. Volume shape factor (f ) Is greater than 0.4 and not more than π / 6, and (c) 0.005 to 3.0% by weight (based on thermoplastic polyetheretherketone) of silicone resin particles having an average particle size of 0.01 to 4 μm, from an intimate mixture. This is accomplished by the biaxially oriented polyetheretherketone film formed.

The thermoplastic polyether ether ketone in the present invention is a constitutional unit. Is a polymer alone or consisting of this unit and other constitutional units.

As other structural units, for example, Etc. In the above structural unit, A is a covalent bond, oxygen, --SO _2- , --CO-- or a divalent lower aliphatic hydrocarbon group, and Q and Q'may be the same or different. CO- or -SO ₂ - and is, n is 0 or 1. These polymers are described in JP-B-60-32642, JP-B-61-10486 and JP-A-57-137116.

The thermoplastic polyether ether ketone may be blended with a resin such as polyarylene polyether, polysulfone, polyarylate, polyester, or polycarbonate for the purpose of improving fluidity, or may be a stabilizer, an antioxidant, an ultraviolet absorber. You may include the additive like the above.

The thermoplastic polyether ether ketone, as described above,
It is known per se and can be produced by a method known per se.

The above-mentioned thermoplastic polyetheretherketone has an apparent melt viscosity of 380 ° C. and an apparent shear rate of 1000 sec ⁻¹ , 500 poises to 10000 poises, and further 1000 poises to 5000 poises.
Those in the poise range are preferable from the viewpoint of film-forming property and film property.

The biaxially oriented polyetheretherketone film of the present invention becomes clear from the following description of Ra which defines the flatness of the film surface, and has many fine projections on the film surface.

The large number of fine projections originates from the large number of substantially inert solid microparticles contained according to the invention dispersed in a thermoplastic polyetheretherketone.

In the present invention, the silicon resin fine particles (II) have the following formula (A) RxSiO ₂ -x / ₂ (A) where R is a hydrocarbon group having 1 to 7 carbon atoms, and x is 1 to 1.2. It has a composition represented by.

R in the above formula (A) is a hydrocarbon group having 1 to 7 carbon atoms, and for example, an alkyl group having 1 to 7 carbon atoms, a phenyl group or a tolyl group is preferable. The alkyl group having 1 to 7 carbon atoms may be linear or branched, and examples thereof include methyl, ethyl, n-propyl, iso-propyl, n-butyl, i.
Examples include so-butyl, tert-butyl, n-pentyl, n-heptyl and the like.

Of these, methyl and phenyl are preferable as R, and methyl is particularly preferable.

X in the above formula (A) is 1 to 1.2. When x is 1 in the above formula (A), the above formula (A) is represented by the following formula (A) -1 RSiO _1.5 (A) -1 where R is defined as above. You can

The composition of the above formula (A) -1 has the following structural portion in the three-dimensional polymer chain structure of a silicone resin; It is derived from.

Further, when x is 1.2 in the above formula (A), the above formula (A) is the following formula (A) -2 R _1.2 SiO _1.4 ... (A) -2 where R is the same as above. Can be expressed as

The composition of the above formula (A) -2 is represented by the following formula (A) ′ R ₂ SiO ... (A) ′ in which 0.8 mol of the structure of (A) -1 is used and the definition of R is the same as above. It can be understood that the structure consists of 0.2 mol.

The above formula (A) 'represents the following structural portion in the three-dimensional polymer chain of silicone resin; Derived from.

As can be understood from the above description, the composition of the above formula (A) of the present invention consists essentially of, for example, only the above formula (A) -1 structure or the above formula (A) -1 structure. It can be seen that the structure of the above formula (A) -2 is composed of coexisting structures in a state where they are randomly bonded at an appropriate ratio.

The silicone resin particles of the present invention preferably have the above formula (A)
In, x has a value between 1 and 1.1.

The silicone resin particles (II) of the present invention have the following formula (B) f = V / D ³ (B) where V is the average volume per particle (μm ³ ) and D is the particle Is the average maximum particle size (μm) of which the volume shape factor (f) is larger than 0.4 and is π / 6 or less.

In the above definition, the average maximum particle size of the particles of D should be understood to mean the distance having the maximum length of the distance between any two points where any straight line across the particle intersects the perimeter of the particle.

The preferred f value of the silicone resin particles of the present invention is 0.44 to π
/ 6, and a more preferable value of f is 0.48 to π / 6. f
A particle with a value of π / 6 is a true sphere. The use of silicon resin particles having an f value smaller than the lower limit makes it extremely difficult to control various film surface characteristics.

The silicone resin particles used in the present invention further have 0.01
It has an average particle size of ˜4 μm. Average particle size is 0.01 μm
If the particles smaller than this are used, the effect of improving the slidability and abrasion resistance is insufficient, whereas if the particles having an average particle size larger than 4 μm are used, only a film having insufficient flatness in plane is obtained. Absent.

The average particle size is preferably between 0.05 and 3 μm.

The average particle size referred to here is understood to be the diameter at the cumulative 50% point of the equivalent spherical particle size distribution calculated based on the Stokes equation.

The silicone resin particles used in the present invention are represented by the following formula RSi (OR ') _3, wherein R is a hydrocarbon group having 1 to 7 carbon atoms and R'is a lower alkyl group. Silane or its partially hydrolyzed condensate, in the presence of ammonia or amines such as methylamine, dimethylamine, ethylenediamine,
It can be produced by hydrolysis and condensation with stirring. According to the method using the starting material,
Silicon resin particles having a composition represented by the above formula (A) -1 can be produced.

R ₂ Si (OR ′) ₂ wherein R and R ′ are the same as defined above. A dialkoxysilane represented by the above is used together with the above trialkoxysilane, and according to the above method, the above formula (A It is possible to produce silicon resin particles having a composition represented by) -2.

The silicone resin particles used in the present invention have the following formula γ = D ₂₅ / D _75, where γ is the particle size ratio, and D ₂₅ is the particle size when the cumulative weight of the fine particles is 25% of the total weight. And then D ₇₅
Is the particle size when the integrated weight is 75% of the total weight, but the ratio of the integrated weight is measured from the larger particle size. The particle size ratio (γ) is preferably It is in the range of 1 to 1.4. This particle size ratio is more preferably 1 to 1.3
, Particularly preferably in the range of 1 to 1.3,
It is particularly preferably in the range of 1-1.15.

The intimate mixture of the thermoplastic polyetheretherketone (I) and the silicone resin fine particles (II) forming the film of the present invention is the intimate mixture of the fine particles (II) and the fine particles (II) of 0.005 to It contains 3.0% by weight (based on the thermoplastic polyetheretherketone).

If the amount of the fine particles (II) is less than 0.005% by weight, the effect of improving the slipperiness and abrasion resistance of the film is insufficient, while 3.
If it exceeds 0% by weight, the flatness of the film is deteriorated.

The amount of the fine particles (II) is preferably 0.01 to 0.5% by weight (based on the thermoplastic polyetheretherketone).

As described above, the above-mentioned silicon resin fine particles used in the present invention impart surface flatness, slipperiness and abrasion resistance to the polyetheretherketone film. In particular, as a reason for giving excellent abrasion resistance, according to the research of the present inventors, it is clear that the silicone resin fine particles have a very large affinity with the polyether ether ketone mixed therein. Was done.

That is, the film surface of the present invention containing the silicon resin particles is subjected to ion etching to expose the silicon resin particles in the film, and the surface is observed with a scanning electron microscope. In substantial contact with a ketone substrate,
In other words, a state is observed in which almost or no void is observed between the peripheral surface and the polyetheretherketone substrate.

Further, the fact that the silicon resin fine particles of the film of the present invention have a high affinity with the polyether ether ketone substrate is evaluated by a void ratio (ratio of the long diameter of the particle to the long diameter of the void) defined later as another measure. The film of the present invention has substantially all void ratios of 1.0 to 1.5, and most of them have 1.0 to 1.3.
It became clear that the thing of 1.0-1.5 occupies the main part.

The biaxially oriented polyetheretherketone film of the present invention, which has few voids and has a void ratio close to 1.0, is particularly excellent in abrasion resistance and dielectric breakdown voltage.

Generally, thermoplastic polyether ether ketone and inert particles (lubricant) have no affinity. For this reason, when the melt-cast unstretched polyetheretherketone film is biaxially stretched, peeling occurs at the boundary between the fine particles and the polyetheretherketone, and a void is usually formed around the specific particles. . This void is, the larger the fine particles, the closer the shape is to a sphere, the more difficult the fine particles are deformed by a single particle, and the larger the stretching area ratio when stretching the unstretched film, and the lower the temperature is. Tends to grow. The larger the void, the more gradually the shape of the protrusion becomes so that the friction coefficient becomes high, and with that, the void of the biaxially oriented polyetheretherketone film that occurs during repeated use comes off, It reduces durability and causes shavings.

As described above, in the case of the conventional inorganic inert lubricant, the void amount around the lubricant is considerably large, and in the high-strength polyetheretherketone film, the void becomes larger, and as a result, the calendering step of the magnetic tape, etc. In general, the abrasion resistance is poor in the working process. In addition, in the case of capacitors, this leads to a decrease in dielectric breakdown voltage.

The silicon resin fine particles used in the present invention have a high affinity with the polyether ether ketone substrate as described above, and therefore, voids are less likely to occur around the particles. Therefore, the frequency of generating voids that generally become larger as the particles become larger can be suppressed to a low level when the above-mentioned silicon resin particles are used. Therefore, according to the present invention, the silicon resin particles are used as relatively large particles. In addition to that, it has the advantage of using two types of particles in combination with relatively small particles with a low void generation rate, and also has good running properties, wear resistance, fatigue resistance, electrical insulation and transparency. It has been revealed that it can provide an excellent film.

That is, such a biaxially oriented polyether ether ketone film has (I) a thermoplastic polyether ether ketone, (II) (a) has a composition represented by the above formula (A), and (b) has the above formula (B). Defined volume shape factor (f)
Of more than 0.4 and π / 6 or less, and (c) 0.005 to 1% by weight of silicon resin fine particles (based on thermoplastic polyetheretherketone) and (III) 0.01 to 1 μm having an average particle diameter of 0.3 to 4 μm. Formed from an intimate mixture of 0.005 to 1% by weight (based on thermoplastic polyetheretherketone) of inert particles having an average particle size of less than the average particle size of the silicone resin particles. It is a biaxially oriented film that has been processed.

The thermoplastic polyether ether ketone (I) and the silicone resin fine particles (II) are as described above. However, in this case, the average particle size of the silicone resin particles is
Larger particles of 0.3-4 μm are used.

As the inert fine particles (III) having an average particle diameter smaller than that of the silicon resin fine particles, those which are inert and insoluble in the thermoplastic polyetheretherketone and which are solid at room temperature are used. These may be externally added particles or internally generated particles. Further, for example, it may be a metal salt of an organic acid or an inorganic substance. Preferred inert particles (A) include calcium carbonate, silicon dioxide (hydrate,
Diatomaceous earth, silica sand, quartz etc.), alumina, SiO ₂
Silicates containing 30% by weight or more (eg, amorphous or crystalline clay minerals, aluminosilicate compounds (including calcined products and hydrates), warm asbestos, zircon, fly ash, etc., Mg, Zn, Zr and Ti oxides, Ca and Ba sulfates, Li, Na and Ca phosphates (including monohydrogen and dihydrogen salts), Li, Na and K benzoates, Ca, Ba , Zn and M
n terephthalate, Mg, Ca, Ba, Zn, Cd, Pb, Sr, Mn, Fe, Co
And titanates of Ni, chromates of Ba and Pb, carbon (eg carbon black, graphite etc.), glass (eg glass powder, glass beads etc.), MgCO ₃ ,
Fluorite and ZnS are exemplified. Particularly preferred are silicic acid anhydride, hydrous silicic acid, aluminum oxide,
Aluminum silicate (including calcined products, hydrates, etc.), 1 lithium phosphate, 3 lithium phosphate, sodium phosphate, calcium phosphate, barium sulfate, titanium oxide, lithium benzoate, double salts of these compounds (hydrates ), Glass powder, clay (including kaolin, bentonite, clay etc.),
Examples are talc and diatomaceous earth. Of these inert fine particles (III), externally added particles are particularly preferable.

The silicon resin fine particles (II) have an average particle size of 0.3 to 4 μm. Preferably 0.3 to 2 μm, particularly preferably 0.5
It has an average particle size of ˜1.5 μm.

Further, the inert particles (III) have an average particle diameter of 0.01 to 1 μm, and are used in combination as an average particle diameter smaller than the average particle diameter of the above-mentioned silicon resin fine particles (II).

The inert fine particles (III) preferably have an average particle size of 0.05 to 0.8 μm, more preferably 0.1 to 0.5 μm.

The content of the inert fine particles (III) is 0.005 to 1% by weight based on the thermoplastic polyetheretherketone, but 0.01
-1% by weight, more preferably 0.01-0.5% by weight, especially 0.05-0.3% by weight. On the other hand, the content of silicone resin particles (II) is 0.005 with respect to thermoplastic polyether ether ketone.
~ 1% by weight, but 0.01 to 1% by weight, and further 0.04 to 0.
5, especially 0.1 to 0.5% by weight is preferred.

If the content of the inert fine particles (III) or the silicone resin fine particles (II) is too small, the synergistic effect of using two kinds of particles, large and small, cannot be obtained, and the running property, wear resistance, fatigue resistance, crushing property, It is not preferable because characteristics such as end face uniformity are deteriorated.
On the other hand, if the content of the inert particles (III) is too large, the frequency of occurrence of voids due to small particles in the polymer tends to increase, resulting in wear resistance, fatigue resistance, crush resistance, insulation voltage, and transparency. Sex and so on.

If the content of the silicone resin fine particles (II) is too large,
The film surface is too rough and, for example, the electromagnetic conversion characteristics of the magnetic tape are deteriorated, which is not preferable.

In producing the biaxially oriented film of the present invention, these fine particles are used for intimately mixing the silicone resin fine particles or the inert fine particles with polyether ether ketone,
Before or during the polymerization of the polyetheretherketone, in a polymerization kettle, in the extruder when pelletizing after the completion of the polymerization, or in the extruder when melt-extruding into a sheet form, thoroughly knead with the polyetheretherketone. Good.

The polyetheretherketone film of the present invention is obtained, for example, by melt-extruding a thermoplastic polyetheretherketone at a temperature of melting point (Tm: ° C.) + 30 ° C. to (Tm + 90) ° C. to obtain an unstretched film, and the unstretched film is uniaxially stretched. Direction (longitudinal direction or transverse direction) at a temperature of (Tg-10) to (Tg + 45) ° C (however, Tg: the glass transition temperature of polyetheretherketone) by 1.5 times or more, particularly 2.5 times or more, and then the above Direction perpendicular to the stretching direction (when the first stage stretching is in the longitudinal direction,
(Tg + 10) to (Tg + 40) in the second stage stretching is in the lateral direction
It can be produced by stretching at a temperature of ° C at a draw ratio of 2.5 to 5.0 times. In this case, the area draw ratio is preferably 4 times or more, more preferably 6 times or more. The stretching means may be simultaneous biaxial stretching or sequential biaxial stretching.

Further, the biaxially oriented film can be heat set at a temperature of (Tg + 70) ° C. to Tm (° C.). For example, it is preferable to heat-set the polyether ether ketone film at 200 to 350 ° C. The heat setting time is, for example, 1 to 120 seconds.

The thickness of polyetheretherketone film is 1-25
0 μm, more preferably 1 to 125 μm, and particularly preferably 1 to 75 μm.

The biaxially oriented polyetheretherketone film of the present invention is characterized in that it has uniform uneven surface characteristics, excellent slipperiness, heat resistance and abrasion resistance, and the generation of scratches, white powder, etc. is extremely small. This biaxially oriented polyetheretherketone film can be widely used for various applications by utilizing these characteristics. For example, when it is used as an electrical insulation material, motor insulation, and wire coating, excellent heat resistance and workability can be obtained. Further, when used for capacitors, a high-grade capacitor having a high operating temperature can be obtained due to its low friction coefficient, excellent winding property, low crush load and its excellent heat resistance. Also, FPC
When used for (flexible printed circuit) applications,
It is possible to obtain FPC with excellent solder resistance. Further, when it is used as a base film for magnetic recording such as video, audio, computer, etc., excellent electromagnetic conversion, slipperiness, running durability, etc. can be obtained. In particular, it is suitable as a base film for vacuum deposition or sputtering in which a metal thin film is applied to the base film because of its heat resistance.

Biaxially oriented polyetheretherketone film is preferable for electric shock, capacitor, FPC, metal thin film magnetic recording medium, but also widely used as a base film for coating type magnetic recording medium, vapor deposition, dry transfer, etc. can do.

Various physical properties and characteristics in the present invention are measured and defined as follows.

(1) Average particle size (DP) Shimadzu CP-50 Centrifugal particles
Size Analyzer (Centrifugal Particle Size An
alyser). The particle diameter corresponding to 50 mass% was read from the integrated curve of the particles of each particle diameter calculated based on the obtained centrifugal sedimentation curve and the abundance thereof, and this value was used as the average particle diameter (Book Measurement technology ", published by Nikkan Kogyo Shimbun, 1975, pp. 242-247).

(2) Particle size distribution ratio (γ) Based on the centrifugal sedimentation curve obtained in the measurement of the average particle size, an integrated curve of particles of each particle size and their abundance is calculated and drawn, The cumulative weight of particles accumulated from the larger
Read the particle size corresponding to 25 mass percent (D ₂₅ ) and the particle size corresponding to the cumulative mass of particles of 75 mass percent (D ₇₅ ) and divide the former value by the latter value (D ₂₅ / D ₇₅ ) Calculate the particle size distribution ratio (γ) of each particle.

(3) Frictional coefficient of film (μk) A film cut into 1/2 inch width at a temperature of 20 ° C and a humidity of 60% is attached to a fixed rod (surface roughness 0.3 μm) at an angle θ = 152.
Contact at / 180π radian (152 °) and move (rub) at a speed of 200 cm per minute. When the tension controller is adjusted so that the inlet tension T ₁ is 35g, the outlet tension (T ₁ : g) is detected by the outlet tension detector after the film has run 90m, and the running friction coefficient μk is calculated by the following formula. .

μk = (2.303 / θ) log (T ₂ / T ₁ ) (4) Film surface flatness CLA (Center Line Averag) JIS B
It measured according to 0601. Using a stylus type surface roughness meter (SURFCOM3b) manufactured by Tokyo Seimitsu Co., Ltd., the radius of the needle is 2μ and the load is
A chart (film surface roughness curve) was drawn under the condition of 0.07 g. A roughness curve Y = f (x) is obtained by extracting a portion having a measurement length L from the film surface roughness curve in the direction of the center line, and defining the center line of the extracted portion as the X axis and the direction of longitudinal magnification as the Y axis. The value (Ra: μm) given by the following equation is defined as the flatness of the film surface.

In the present invention, 8 pieces were measured with a reference length of 0.25 mm, and Ra was expressed as an average value of 5 pieces excluding 3 pieces having the larger values.

(5) Void ratio A small piece of sample film is fixed on a sample stand for a scanning electron microscope, and a sputtering device manufactured by JEOL Ltd. (JFC-1100) is used.
Type ion sputtering apparatus), the film surface was subjected to ion etching treatment under the following conditions. The sample stage was set in the bell jar, the degree of vacuum was raised to a vacuum state of about 10 ⁻³ Torr, and ion etching was performed at a voltage of 0.25 KV and a current of 12.5 mA for about 10 minutes. Further, gold sputtering was applied to the film surface with the same apparatus to form a gold thin film layer of about 200 liters, and the measurement was performed with a scanning electron microscope 10,000 to 30,000 times.
The voids were measured only for lubricants having a particle size of 0.3 μm or more.

(6) Haze According to JIS-K 674, Nippon Seimitsu Optical Co., Ltd., integrating sphere type HTR
The haze of the film was measured with a meter.

(7) Volumetric shape factor (f) Photographs of particles by a scanning electron microscope, for example, 5000 times 10
Field-of-view photography, for example, image analysis processor Luzex 500
(Manufactured by Nippon Regulator Co., Ltd.), the average value of the maximum diameters was measured for each visual field, and the average value of 10 visual fields was calculated and designated as D.

The average volume (V = (π / 6) d ³ ) of the particles was obtained from the average particle diameter d of the particles obtained in the item (1) of the measurement method, and the shape factor f was calculated by the following equation.

In the formula f = V / D ³ , V represents the average volume (μm ³ ) of the particles, and D represents the average maximum particle size (μm) of the particles.

(8) Dielectric breakdown voltage and abnormal dielectric breakdown rate Dielectric breakdown voltage is measured by the method specified in JIS-C-2318. The average value of n = 100 is adopted, and the ratio (%) of those showing a value of 1/3 or less of this average value is taken as the dielectric breakdown abnormality rate.

(9) Evaluation of the element end face shape after the element end face is not uniform and flattened A film of 10μ is vapor-deposited on aluminum and slit into a width of 20mm. A winding core with an outer diameter of 3mm has a winding tension of 40g and a winding speed of 30c.
An element wound with a length of 4 m at m / sec was made, and regarding the unevenness of the element end faces, the one where all the end faces were perfectly aligned was marked with ○, and some of them were slightly uneven, but the degree was also small. ,
The ones that make no difference in practical use are △, and those that cannot be used are ×
And

When the element was flattened by a press, the element end face shape after flattening was evaluated as follows: the film layers were flattened in a straight line with no gaps, and there were no gaps. If there is no problem, it is indicated as △, and if it is crushed but not uniform and there are gaps between the film layers, it cannot be used.

(10) The aggregation film of the lubricant was magnified 20 times under polarized light and evaluated by measuring the number of aggregate lubricants of 25 μ or more among those that shine in a dark field with the polarizing plate orthogonal. The measuring area is 10 cm ² and 1 cm ²
Number of pieces per piece is 0-10, ○, 10-30 pieces is △, 30
More than one was marked as x.

(11) Comprehensive evaluation of capacitors Comprehensively evaluated electrical characteristics such as crushability, winding workability, handling workability, vapor deposition processability, dielectric breakdown voltage, and dielectric breakdown anomaly rate. A sample having a slightly inferior surface but having no problem in practical use is rated as O, a sample having practical problems as Δ, and a sample that cannot be used as X.

[Examples] Hereinafter, the present invention will be further described with reference to Examples.

Examples 1 to 7 Thermoplastic polyetheretherketone (manufactured by ICI: polyetheretherketone 380G) was mixed with silicon resin fine particles and inert particles in the proportions shown in Table-1, and after blending, at 380 ° C. by an extruder. It is extruded and cast on a casting drum kept at a temperature of 80 ° C to make a 90μ unstretched film, which is stretched 2.7 times in the longitudinal direction at 160 ° C and further fed to a tenter to 3.5 ° C at 160 ° C in the transverse direction. The film was double-stretched and heat set at 250 ° C. for 30 seconds. The characteristics of these films are shown in Table-1.

Comparative Examples 1 to 3 The same polymer as in Example 1 was used, and the same procedure as in Example 1 was carried out except that only the lubricant was changed to those shown in Table 1.

The characteristics of these films are shown in Table-1.

The silicon resin fine particles shown in Table-1 have the average particle diameter shown in Table-1 and have a volumetric shape factor of 0.52 to 0.48.
Moreover, the particle size distribution ratio (γ) is 1.1 to 2.0. (Composition: CH ₃ Si O _1.5 ) From the results shown in Table 1, it can be seen that the film of the present invention has a flat surface, a small coefficient of repeated friction, and excellent slipperiness. Further, the film of the present invention shows little aggregation of the lubricant, and it is found that it is very excellent as a film for capacitors.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location B29K 73:00 B29L 7:00 4F

Claims (8)

[Claims] 1. (I) Thermoplastic polyether ether ketone, and (II) (a) The following formula (A) RxSiO ₂ -x / 2 (A) where R is a hydrocarbon having 1 to 7 carbon atoms. Is a group, and x is a number of 1 to 1.2. (B) The following formula (B) f = V / D ³ (B) where V is per particle the average is the volume ([mu] m ³⁾ and D is less large and [pi / 6 volume shape factor (f) is from 0.4 defined by is the average maximum particle diameter of the particles ([mu] m), and (c) 0.01 to A biaxially oriented polyetheretherketone film formed from an intimate mixture of 0.005 to 3.0% by weight (based on thermoplastic polyetheretherketone) of silicone resin particles having an average particle size of 4 .mu.m. 2. In the above formula (A), R has 1 to 7 carbon atoms.
The film according to claim 1, which is a linear or branched alkyl group, a phenyl group or a tolyl group. 3. The film according to claim 1, wherein in the formula (A), x is a number from 1 to 1.1. 4. The film according to claim 1, having a volume shape factor (f) of 0.44 to π / 6. 5. The film according to claim 1, wherein the average particle size is between 0.05 and 3 μm. 6. A film according to claim 1, wherein the amount of the silicone resin fine particles is 0.01 to 1.5% by weight (based on the thermoplastic polyetheretherketone). 7. The silicone resin fine particles are represented by the following formula (C) γ = D ₂₅ / D ₇₅ (C) where D ₂₅ is an average particle diameter (μm) when the cumulative weight of the particles is 25%. The particle size distribution ratio (γ) defined by D ₇₅ is the average particle size (μm) when the cumulative weight of the particles is 75%. The value is between 1 and 1.4. Film. 8. (I) Thermoplastic polyether ether ketone, (II) (a) The following formula (A) RxSiO ₂ -x / 2 (A) where R is a hydrocarbon group having 1 to 7 carbon atoms. And x is a number from 1 to 1.2, (b) the following formula (B) f = V / D ³ (B) where V is the average per particle Volume shape factor (f) is greater than 0.4 and π / 6, where D is the volume (μm ³ ) and D is the average maximum particle size (μm) of the particles.
And (c) 0.005 to 3.0% by weight of silicone resin particles (based on thermoplastic polyetheretherketone) having an average particle size of 0.3 to 4 μm and (III) having an average particle size of 0.01 to 1 μm. Claims 1. Formed from an intimate mixture of 0.005 to 3.0% by weight (based on thermoplastic polyetheretherketone) of inert fine particles having an average particle size smaller than the average particle size of the silicone resin particles. The film described in the item.