JPS6082326A - Oriented polyester film - Google Patents

Abstract

PURPOSE:To elevate the flatness, smoothness and adhesivity of the surface by arranging fine particles with a specified diameter and a specified higher fat acid to be contained in a specified content respectively while the surface roughness and the coefficient of static friction are within a specified range. CONSTITUTION:0.05-2pts.wt. of fine particles with the average size of 0.05-3mum and 0.05-2pts.wt. of a compound mainly composed of monocarboxylic acid, as higher fat ester or ester thereof having C10-33 are contained in 100pts.wt. of polyester. The surface roughness Ra shall be 0.01-0.025mum and the coefficient of static friction 0.3-1. The fine particles herein used may be inactive particles and organic particles insoluble in polyester or the like as well. The compound composed of monocarboxylic acid as higher fat which may be used includes capric acid, lauric acid and stearic acid. Aboveall, monocarboxylic acid as higher fat having C20-32 features the potentiality of improving easy-to-smooth property. The compound composed of ester monocarboxylate as higher fat may be those such as montanic acid ethylene glycolester.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an oriented polyester film containing fine particles and a specific compound and having improved flatness, slipperiness, and adhesion of one surface. be.

[Prior art]

In recent years, oriented polyester films have made remarkable progress in fields such as magnetic recording media such as magnetic tapes and magnetic disks, capacitors, photographs, microfilms, and packaging.

In each application of this oriented polyester film, 2
Strict surface control is required. In other words, for magnetic recording media such as magnetic tapes and magnetic disks, to prevent recording disturbances, for capacitors to prevent insulation defects, and for photographs and microfilms to prevent disturbances in image quality. Furthermore, for packaging purposes, the surface of the oriented polyester film must be flat so as not to impair transparency or aesthetic appearance. In addition, common to all of these applications, workability and quality must be maintained both during unwinding, processing, winding, and slitting when producing products for those applications, and when using them after producing 2M products. From both sides, the surface of the polyester film needs to be slippery.

In addition, lubricity is an important property when forming an oriented polyester film from the viewpoint of stable and economical production with less tearing. However, the long-awaited flatness and smoothness are originally contradictory surface properties. In other words, it is extremely difficult to satisfy both properties at the same time, and if priority is given to flatness, smoothness must be sacrificed to some extent.
If priority is given to smoothness, flatness must be sacrificed to some extent.

Conventionally, the following nine techniques have been proposed for the purpose of achieving both flatness and smoothness.

■ A method in which part or all of the Catalyst 1 color inhibitor used during polyester synthesis is precipitated during the reaction process and present in the film as fine particles (internal particles) (hereinafter referred to as internal particle generation method) ■ Titanium dioxide, talc, kaoli A method of adding inert particles to the polyester synthesis reaction system such as night, calcium carbonate, and silicon oxide (hereinafter referred to as external particle addition method)
.

■ Combination of ■ and ■ Method of adding neutral or partially neutralized monk wax metal salt or monk wax ester metal salt (Received Japanese Patent Application Laid-Open No. 139551/1983) or polyol having 6 or more hydroxyl groups A method of adding an ester product (JP-A-57-195143). (hereinafter referred to as organic lubricant addition method).

However, the oriented polyester film by such conventionally proposed technology is

(2) In the internal particle generation method, there are many coarse particles mixed in, probably due to the strong cohesive force between the nine particles, and the coarse particles deteriorate the flatness of the film surface.

Furthermore, it has the disadvantage of insufficient lubricity.

■ The external particle addition method has the disadvantage that it is not possible to achieve both flatness and smoothness because secondary agglomeration of single particles, roughness of the average particle size, and inclusion of coarse particles are inevitable.

■ Even if the internal particle generation method and the external particle addition method are used together, the drawbacks of each cannot be overcome.

■ Among organic lubricant addition methods, JP-A-56-13955
In the technique of Publication No. 1, the organic melt bleeds out onto the film surface.

The drawback is that it lacks lubricity, JP-A-57-1.95
In the technology of Publication No. 143, if an organic solvent is added during polymerization, it will gel and dissolve, and if it is added by adding it (a method in which it is added later to the raw material after polymerization), it will be added during melt extrusion. All have the disadvantage that satisfactory surface properties (flatness, smoothness) cannot be obtained because the viscosity drops rapidly.

Even if any of these films were used to make a magnetic tape, there was a drawback that the running properties of the magnetic tape and the electromagnetic conversion characteristics could not be achieved at the same time.

[Purpose of the invention]

The object of the present invention is to provide an oriented polyester film that does not have the above-mentioned drawbacks, that is, has poor three properties: flatness on two surfaces, smoothness, and adhesiveness.

[Structure of the invention]

The present invention uses 100 parts by weight of polyester.

A, fine particles with an average particle size of 0.005 to 6 μm
~2 parts by weight.

B, does not contain at least 0005 to 2M parts of at least one compound consisting of a higher aliphatic monocarboxylic acid having 10 to 63 carbon atoms or an ester thereof, and has a surface roughness Ra of 0001 to 1; 0.
025 μm and a static friction coefficient μs of 0.6 to 1.

The polyester in the present invention is a polyester containing an aromatic dicarboxylic acid as a main acid component and an alkylene glycol as a main glycol component.

Specific examples of aromatic dicarboxylic acids include terephthalic acid,
Isophthalic acid, naphthalene dicarboxylic acid.

Diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid.

Diphenylsulfone dicarboxylic acid, diphenylketone dicarboxylic acid, anthracene dicarboxylic acid.

α,β-bis(2-10ulfenoxy)ethane-4,4
'-dicarboxylic acids and the like. 9% of these
Terephthalic acid is preferred.

Specific examples of alkylene glycol include ethylene gelicol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, hexylene glycol, and the like. Among these, ethylene glycol is particularly desirable.

Of course, these polyesters may be homopolyesters or copolyesters (copolymerized polyesters), and examples of copolymerized components include diethylene glycol, propylene glycol, neopentyl glycol + e) alkylene glycol, Diol components such as p-xylylene glycol, 1,4-cyclohexane dimetatool, and 5-sodium sulforesorcin.

Adipic acid, sebacic acid, phthalic acid, inphthalic acid, 2
．． Dicarboxylic acid components such as 6-naphthalene dicarboxylic acid and 5-sodium sulfoisophthalic acid.

Examples include polyfunctional dicarboxylic acid components such as trimellitic acid and pyromellitic acid, and oxycarboxylic acid components such as p-oxyethoxybenzoic acid.

Note that, of course, the above polyester contains known additives,
For example, antistatic agents, heat stabilizers, ultraviolet green absorbers, etc.1
It may be added in an amount that does not impair the effects of the present invention.

The fine particles in the present invention are at least one type selected from 9 well-known internal particles, 11 inert particles, and organic particles insoluble in polyester.

Internal particles are particles that are produced by combining a metal compound added during polyester synthesis, such as at least one compound such as a calcium compound, a magnesium compound, a lithium compound, or a phosphorus compound, with components constituting the polyester.

One type of inert particle is the periodic table of elements 11.1.
．． Chemically inert selected from oxides or inorganic salts of elements of group IV, such as calcium carbonate, wet silica (silicon dioxide), dry silica (silicon dioxide), aluminum silicate, obtained synthetically or naturally. (kaolinite).

Examples include barium sulfate, calcium phosphate, Merck, titanium dioxide, aluminum oxide, aluminum hydroxide, calcium terephthalate, calcium silicate, and the like.

The nine types of organic particles insoluble in polyester are not particularly limited, and include, for example, fluorine-containing fine particle polymers and fine powders of crosslinked polymers.

The average particle size of the above-mentioned fine particles must be 0.05 to 3 μm, preferably 0.1 to 2 μm. 0.1
If it is less than 6 μm, the film may not have sufficient lubricity.
If it exceeds mn, the flatness of the film will deteriorate. The content of the fine particles is preferably 0.005 to 2 parts by weight, preferably 0.005 to 1 part by weight, and more preferably 0.005 to 1 part by weight, based on 100 parts by weight of the polyester.
It is 1 to 0.5 parts by weight.

If the content is less than the lower limit of the above range, the film-
On the one hand, the coefficient of friction between films or between a film and metal is large, and the smoothness is poor.

When the content exceeds the upper limit of the above-mentioned range, coarse particles are often generated and the surface roughness becomes large.

Flatness deteriorates. If a magnetic tape is made using a film with a content outside the appropriate range as described above, running properties and electromagnetic conversion characteristics will not be compatible.

What is the compound in the present invention whose main component is a higher aliphatic monocarboxylic acid having 10 to 63 carbon atoms?

Specific examples include capric acid, lauric acid, stearic acid, nonadecanoic acid, arachidic acid, and behenic acid.

Melisic acid, lignoceric acid, heptalotylic acid, moncnic acid, hentriacontanoic acid, petroselic acid.

Oleic acid, erucic acid, linoleic acid, and higher aliphatic monocarboxylic acids having 20 to 32 carbon atoms are characterized by significantly improved slipperiness.

The higher aliphatic monocarboxylic acid ester in the present invention refers to the above-mentioned higher aliphatic monocarboxylic acids.

It is obtained by partially or entirely esterifying it with a monohydric or dihydric alcohol having 2 to 36 carbon atoms. Specifically, Moncun acid ethylene glycol ester, Moncun acid ethyl ester, Moncun acid ethyl ester, Moncun acid ceryl, octacosyl lignocerate, mericyl lignocerate, ceryl lignocerate, myricyl cerotate, seryl cerotinate, etc. Wax, carnauba wax, beeswax, candelilla wax, wax wax, prickly wax, and the like are also preferably used.

In the present invention, the main component refers to a composition containing 500 parts by weight of the compound.

In the present invention, when the number of carbon atoms in the higher aliphatic monocarboxylic acid is less than 10, bleed-out to the film surface is severe and adhesiveness is extremely poor.

If the number of carbon atoms exceeds 33'f:, lubricity cannot be obtained.

In the present invention, as for the ester consisting of a higher aliphatic carboxylic acid and an alcohol, the number of carbon atoms of the acid and the alcohol constituting the ester are preferably 18 to 3.
6. More preferably, esters obtained in a combination of 20 to 32 are desirable because they can impart good lubricity.

The present invention includes higher aliphatic monocarboxylic acids.

The content of at least one compound consisting of the ester is based on 100 parts by weight of the polyester.

It should be 0.005 to 2 parts by weight, preferably 0.005 to 2 parts by weight.
．． 01 to 1 part by weight, more preferably 0.05 to 0.5 part by weight
M parts, most preferably greater than 0.1 parts by weight and 0.5 parts by weight. If the above content is less than 0.005 parts by weight, the flatness and slipperiness of the film will hardly be obtained, and if it exceeds 2 parts by weight, bleed-out to the film surface will be severe and the adhesion will be significantly impaired. It will be inferior.

As described above, in the present invention.

It is necessary that both A, fine particles and B, a compound consisting of a higher aliphatic monocarboxylic acid and its ester (hereinafter abbreviated as "higher fatty acid compound") are contained.

The effects of the present invention cannot be achieved by containing only A or only B. The reason why it is necessary to contain both is
This is because B has a synergistic effect of finely dispersing A in the polyester.

The surface roughness (Ra) in the present invention is measured by the method described below, and the range thereof in the present invention must be o, o o i to 0.025 μm, preferably O ,,001-0.023 μm.

More preferably, it is 0001 to 0.018 μm, and most preferably o, o oi to 0.014 μm. If the surface roughness (Ra) is less than 1 μm, it is too flat and scratches are likely to occur. On the other hand, Ra is 0.025μ
If it exceeds , flatness is poor. If Ra deviates from the preferred range as described above, a magnetic tape using the film will not have both electromagnetic conversion characteristics and runnability.

The static friction coefficient (Cμs) in the present invention is measured by the method described below, and its range is 0.6
-1, preferably 0, 4-069. More preferably, it is 0.4 to 0.8.

If the static friction coefficient (μB) is less than 0.6, loose winding occurs during operation. On the other hand, if it exceeds 1, the lubricity will be insufficient and high-speed running properties during processing will deteriorate.

In the present invention, the film must be oriented. If it is not an oriented film, it will be difficult to keep both the surface roughness and the coefficient of static friction within the above ranges, and the thickness unevenness and rigidity 1-dimensional stability will be fatally poor. Forms of orientation include -axis orientation, biaxial orientation, etc.

Although any known orientation format can be selected, a biaxial orientation format is preferred. The degree of orientation is such that in the case of -axis orientation, the in-plane birefringence Δn is 0.
．． 02 to D, 25, preferably 0.06 to 020, and in the case of biaxial orientation, the in-plane birefringence Δn is 0 to Q,
15. Preferably 0 to [1,10, city J11 (sum of refractive index 6.2 to 3.42, thickness direction refractive index ratio 0.93
5 to 0.980 is desirable. Here, the internal birefringence Δ
n is 25" using an Atsube refractometer using sodium D line.
Of each refractive index in the vertical direction, horizontal direction, and thickness direction of the film measured at 0.65% RH.

It is the absolute value of the difference in refractive index in the vertical and horizontal directions.

The sum of the in-plane refractive index is the sum of the refractive index in the vertical direction and the refractive index in the horizontal direction. The refractive index ratio in the thickness direction is the refractive index (P) in the thickness direction of the film.

The ratio of the refractive index (Q) in the thickness direction of an amorphous film obtained by melt-pressing the film and quenching it in water at 10°C.

That is, (P)/(Q). If the degree of orientation is outside the above-mentioned preferred range, it is undesirable because it becomes difficult to achieve both flatness and lubricity of the film, and it becomes difficult to achieve both runnability and electromagnetic conversion characteristics of a magnetic tape using the film.

The thickness of the film of the present invention is preferably 3 to 125 μm, preferably 4 to 80 μm, and more preferably 4 to 75 μm.

It is desirable to provide a magnetic layer on at least one side of the film of the present invention to form a magnetic recording medium. This magnetic layer is a well-known magnetic layer made of γ-Fe, 0. ．． γ-F doped with Go
A powdered magnetic material such as θ, 0□ rcro, h or ferromagnetic alloy is dispersed in an organic binder.

A magnetic layer formed by a method of coating with a thickness of 0.6 to 5 μm, or a ferromagnetic metal such as P''e, Co, Ni, or a magnetic alloy containing them, for example, by vacuum evaporation, sputtering, or ion blasting.

1. Any magnetic layer formed with a thickness of 10 to 11000 nm by a method such as air plating may be used; however, the latter is preferable in terms of advantageously exerting the effects of the present invention and improving the accuracy of the magnetic recording medium. It is desirable to provide a magnetic layer of.

Next, a summary of the method for manufacturing the oriented film and magnetic recording medium of the present invention will be described. However, it is not limited to this.

(1) Method for producing oriented film: First, fine particles and a higher fatty acid compound are added to the whole polyester. The method of addition is step 1 of polyester polymerization.
Either before the reaction, 1 reaction, 2 reactions, ''!, or during melt extrusion.Also, the fine particles and higher fatty acid compound,
A method of diluting and mixing polyester with masks containing high concentrations in polyester, either separately or together, is also preferably employed.

Thus, a specific particle source (A) and a higher fatty acid compound (
A polyester containing a specific amount of B) is melt-extruded in an extruder, cast into a sheet, and stretched and oriented using a well-known method. Although the stretching method is not particularly limited, the uniaxial stretching method for obtaining a -axis orientation type is as follows:
On the other hand, biaxial stretching methods to obtain a biaxial orientation format, which is a more desirable orientation format, include simultaneous biaxial stretching, vertical stretching, and vertical stretching using a roll. Horizontal, vertical → horizontal → vertical.

Horizontal → vertical, 2nd vertical → horizontal, 2nd vertical → horizontal → vertical,
Examples include 2-stage vertical → horizontal → simultaneous 2-axis.

Then, if necessary, heat treatment is performed while providing appropriate relaxation.

Then, if necessary, at least one side is subjected to well-known corona discharge treatment, plasma treatment, etc., and then wound up.

(2) Method for producing a magnetic recording medium: The above-described magnetic layer is formed on one side of the oriented film obtained as described above to produce, for example, a magnetic tape.

[Effects and uses of the invention]

The oriented polyester film of the present invention is characterized by containing specific amounts of fine particles having a specific diameter and a specific higher fatty acid compound, and having two surface roughness and a coefficient of static friction within specific ranges. It has the effect of being excellent in adhesion to metals such as , Hirata, I-Calendar IF Margin, printing ink, etc. Also,
The durability of slipperiness. It has the effect of having excellent wear resistance.

Furthermore, since the surface roughness is small, there is also the effect of good transparency (low film haze). Furthermore, it has a good friction coefficient, so it has good running properties and is easy to handle in the film forming/slitting winding/unwinding process and the power EL process after the product, and there is no irregularity in the first roll, no scratches, and no projection transfer. There is.

Because of the above effects, the polyester film of the present invention is suitable for base films for magnetic recording media such as magnetic tapes and floppy disks, optical base films, capacitor base films, graphic base films, and packaging base films. In particular, it is suitable for use as magnetic recording media bases such as video tape recorders and magnetic recording disks, which have recently been required to be smaller and lighter, and as bases for vapor-deposited foil-wound capacitors.

Furthermore, among magnetic recording media, it is particularly suitable for high-density high-density metal tapes, 1M or sputtering tapes and disks, and the most suitable is magnetic recording media. It is used for vapor-deposited tapes where the layer is thin and runnability is important.

When used as a magnetic recording medium, since the film of the present invention has both flatness and slipperiness, it has the effect of superior electromagnetic conversion characteristics and runnability compared to conventionally known magnetic recording media. f: Can be obtained.

The magnetic recording medium using the film of the present invention, which has a high effect, can be used as a magnetic tape, magnetic card, or magnetic disk.
It can be used for computer, audio, video, and measurement applications, and is particularly preferably used for video applications.

[Measurement method and evaluation criteria of characteristics]

The characteristics measurement method and evaluation criteria in the present invention are as follows.

(11 Average particle diameter φ (μm) of fine particles: It was calculated from the equivalent spherical diameter of the particles at the 50% weight point measured by optical microscopy or electron microscopy. Equivalent spherical diameter is the same volume as 2 particles. is the diameter of a sphere with .

(2) Surface roughness Ra (μm): Indicates the value measured by a stylus type surface roughness meter (cutoff 0.
25 mm, measured value at 4 mm. However, J engineering 5-B-
0601).

(3) Static friction coefficient μs: Measured using a slip tester according to ASTM-D-1894B-63.

(J Film Haze Measured according to ASTM-D-1003-52.15
Transparency is good if the film is 6.5 inches or less in terms of μm thickness.

(5) Adhesion (5)-A Aluminum evaporation power Belljar type high vacuum evaporation equipment (manufactured by Japan Vacuum Technology Co., Ltd. E B
H-6 type) at a vacuum level of approximately 1 x 10--Hg A
4 was vapor-deposited to a thickness of about 100 nm, and a commercially available cellophane adhesive tape manufactured by Nichiban Co., Ltd. was attached to the Al-deposited surface.
Evaluation was made based on the At remaining adhesion area after zero peeling.

The criteria for evaluation are as follows.

If the index is 6 or more, it is sufficient for practical adhesive strength.

(5) -B Adhesion of magnetic coating film A commercially available cellophane adhesive tape manufactured by Nichiban Co., Ltd. is pasted on the coated side of a sample coated with magnetic paint, and evaluated by the remaining adhesion area of the magnetic coating film after peeling off at 90 degrees. did. The evaluation was based on the same 5-level index as the aluminum vapor deposition power above.

(51-G Printing ink adhesive strength Apply cellophane printing ink [CC-8T' white, manufactured by Toyo Ink Co., Ltd.] to the film in a metered manner, and
Dry with hot air at 0℃ for 1 minute.

Similar to the aluminum evaporation test above, a cellophane adhesive tape peel test was conducted and evaluated using a 5-level index.

(62 film runnability, μ = 8 A load of 1008 was applied to a film slit to a width of 1/2 inch in an environment of 25°C and 185cmRH.

υ μk was calculated using a quadratic equation based on the winding side tension T when pulled at a take-up speed of 1 cm/sec.

For magnetic tape, μ is preferably 065 or less,
More preferably, it is 0.60 or less, and even more preferably 0.26 or less.

(7) Sliding durability: The surface of the tape-shaped film is made of metal (SUS) FBI
Medium-HJ k" / Fl +mn rA 17
ra n n rFTI peak; FF l fear (jLfh If *), μθ of (3) above was measured. If the difference is within 0.1 for /48 at the start of running, the durability is good. (○), if the difference exceeds 0.1, durability is poor (X)
I evaluate it as.

(8) Abrasion resistance: The surface of the tape-shaped film was repeatedly touched by a metal (SU'S) fixed guide (5 mm diameter) 500 times, and the amount of scratches adhered to the film was observed.
The evaluation was made according to the number as follows.

(9) Running properties of magnetic tape A sample magnetic tape on which the signal of [1[10H2] was recorded.

was loaded into a tape recorder and run at a running speed of 10 c+n/sec while repeating running, opening and stopping.

The test was conducted until the running time reached 100 hours while simultaneously measuring the output. Throughout this period, the tape runs smoothly without sticking to the guide roller, and
Output decrease after hours 7% 2.0 a B g= is considered "good running performance", and that U, 13 is "poor running performance"
It was determined that

+11 Electromagnetic conversion characteristics: When the sample magnetic recording medium is reproduced, the output signal f When viewed in one screen, the output signal strength is 1 and the force and strength signal waveforms are flat. J (If the signal is weak or the signal waveform is deformed, it is ``defective.''

A level in between was determined to be "good."

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on Examples.

Example 1 A transesterification reaction was carried out in a conventional manner using 100 parts by weight of dimethyl terephucrate and 62 parts by weight of ethylene glycol using 0.06 parts by weight of calcium acetate as a catalyst, and the resulting product was mixed with 0.04 parts by weight of ammonium trioxide/timone, Lithium acetate 0.
After adding 0.07 parts by weight and 0.04 parts by weight of calcium acetate, 0.02 parts by weight of phosphorous acid and 0.10 parts by weight of trimethyl phosphate were added, followed by single polycondensation, resulting in an intrinsic viscosity of 0. .618゜Internal particle amount (average particle size 1.0μ?+
1) A polymer containing 0.35 parts by weight (based on 100 parts by weight of polyester) was obtained. Calcium element 1 in the internal particles
, 2 weight staff.

Lithium element 1.9] [%, l, l element 4.9% by weight
(Polyester: A).

100 parts by weight of terephthalic acid and 43 parts by weight of ethylene glycol were kneaded to prepare a slurry. 245' to reactor
The slurry is continuously added at a constant rate to the reactant of 50 parts by weight of terephthalic acid and 215 parts by weight of ethylene glycol stored at 0.05°C, and the esterification reaction is carried out at 245°C under normal pressure, and the resulting water is collected from the sheath column. It was continuously distilled out of the system. The supply time of the slurry was completed in 6 hours and 50 minutes, and the esterification reaction was completed in 4 hours. From the obtained reaction product, an esterification reaction product equivalent to 100 parts by weight of terephthalic acid was transferred to a polymerization apparatus, and 0.045 parts by weight of phosphoric acid, 0.023 parts by weight of antimony trioxide, and an average particle size tyrene glycol slurry were added. , a polycondensation reaction was carried out according to a conventional method.

The obtained polymer had an intrinsic viscosity of 0.615 (5), no internal particles defined in the present invention, and contained 2 parts by weight of calcium carbonate (polyester: B).

A polymer with an intrinsic viscosity of 0.62 without the addition of inert particles was obtained in the same manner as Polyester 2B (Polyester:
C).

Polycondensation was carried out in the same manner as polyester 2B without adding inert particles, and after one reaction, carnauba wax 23
Part of N was added and kneaded for about 10 minutes until the intrinsic viscosity was 0.
．． 610 polymer was obtained (polyester=D).

Polyesters thus obtained: A, B, C.

After blending D and drying under reduced pressure (17D'0.2 hours),
A polymer composition was obtained containing 0.17 parts by weight of internal particles, 0.1 parts by weight of calcium carbonate, and 0.05 parts by weight of culturaba wax, based on 100 parts by weight of polyester.

The composition was melt-extruded at 285°O, cast on a cooling drum at 60°C to form a non-stretched sheet, and then, by a conventional sequential biaxial stretching method, a pair of sheets with a one-peripheral speed difference were first drawn. The film was stretched 6.6 times in the longitudinal direction at 90°C between two rolls. The refractive index is in the vertical direction.

The reeds were 1.64 and 1.54 in the horizontal direction, respectively, and the in-plane birefringence Δn was 0110. Next, it was fed into a tenter and stretched 3.5 times in the horizontal (width) direction at 95'0 while holding both ends with clips. Heat treated for seconds. The biaxially oriented film that came out of the tenter was
Both sides were subjected to total corona discharge treatment at an energy of e min /m' and wound once and twice to obtain a biaxially oriented polyethylene terephthalate film having a thickness of 15 μm. The windability of these films was very good. The refractive index of this film in the vertical direction, horizontal direction, and thickness direction is 1.63, respectively.
It was 1.66°1.50 (P). Also, the refractive index (Q)
was 1.57. Therefore, the in-plane birefringence Δn is 0.05
, the sum of the in-plane refractive indices was 3.29, and the refractive index ratio in the thickness direction was 0.95.

Table 1 shows the results of measuring and evaluating the properties of these films. The film properties showed the same values and results on both sides. From Table 1, it can be seen that the film of Example 1 has a flatness (Ra
), slipperiness (μday), transparency (haze), adhesion (A
(b) Vapor deposition strength; printing ink adhesion strength).

It can be seen that it is excellent in all of running properties (μk), slipperiness durability, and abrasion resistance.

Next, a magnetic paint was applied to one side of the film of the example by a primary method to prepare a magnetic tape.

Namely.

Ferromagnetic alloy powder (Fe-Go) 300 parts by weight Zinc powder (average particle size 2 μm) 25 z Cellulose acetate butylene) 30 1 Epoxy resin 25 z Silicone oil 4I Lecithin 51 Toluene (solvent) 200 z Methyl ethyl ketone (solvent) 200 z Ethyl acetate(
A composition consisting of 100 /
5) Add 180 parts by weight of f: After stirring and mixing for 30 minutes, apply it to one side of the above polyethylene terephthalate film while applying a magnetic field to a dry thickness of 4 μm,
Dry. After that.

After being hardened and mirror-finished, it was slit into 1/2 inch width to make a videotape.

Table 1 also shows the results of evaluating the magnetic tape properties of the film thus obtained.

From the measurement evaluation results of magnetic tape characteristics in Table 1.

It can be seen that the magnetic tape using the film of Example 1 has good magnetic film adhesion, magnetic tape running properties, and electromagnetic conversion characteristics.

Examples 2-7. Comparative Examples 1 to 10 In the same manner as polyester 2B of Example 1, dry silica (SiO,) having an average particle size of 06 μm was added to 100 parts by weight of polyethylene terephthalate instead of calcium carbonate.
(“Aerosil” R-97 manufactured by Nippon Aerosil Co., Ltd.
2) Polyester containing 0 parts by weight of il: A polymer containing 2.3 N parts of montanic acid was obtained in the same manner as D (Polyester 2F).

Polyester thus obtained: A, C, v, E.

Ff: Select appropriate bulk amounts of each, combine and blend, Example 1
A 15 μm thick biaxially oriented polyethylene terephthalate film was obtained in the same manner as above.

The properties of these films are shown in Table 1. Example 7
are within the scope of the claims of the present invention, flatness,
Smoothness, transparency (HT vapor deposition strength, printing ink adhesion), runability (μk), durability of slipperiness.

It can be seen that it is excellent in both abrasion resistance.

On the other hand, each of the films of Comparative Examples 1 to 1 did not meet any of the requirements of the claims of the present invention, and therefore any of the film characteristics was poor.

Next, a co-Ni alloy (C) was applied as a magnetic layer to one side of each film of Examples 2 to 7 and Comparative Examples 1 to 1o.

/Ni -80/20 weight ratio) was vacuum-deposited to a thickness of 10 Dnm, and slit into 1/2 inch width to form a evaporated magnetic tape. ta-these normal chi η° cram school fi11
As a result of the evaluation, all of the examples showed good adhesion of the magnetic layer to the film and running properties of the magnetic tape.

It was excellent in all items of electromagnetic conversion characteristics. On the other hand, the two comparative examples that did not meet any of the requirements of the claims of the present invention had some defects in the magnetic tape characteristics.

Procedure Ne 1 blasphemous book 1. case! 1 display 1981 Patent Application No. 190969 2. Name of the invention oriented polyester film 3. Person who makes corrections 4. Date of correction order spontaneous 5. Number of inventions increasing due to amendment (1) Specification, page 3, line 19 ``Method Ukashi Kaikai'' is corrected to ``Method (Tokukaisho).''

(2) Same, page 9, line 16 Correct "slide" to "active".

(3) Same page 16, lines 12-13 [Correct polyester dilution J to [dilution J with polynisder].

(4) Same page 32 Table 1-(1) “Example 3”
The column "Amount of higher fatty acid compound" in the row "10.3%" is corrected to ro, 30J.

Claims (1)

[Claims] (1) 100 parts by weight of polyester. A, 0.00 fine particles with an average particle size of 0.05 to 6 μm
5 to 2 parts by weight, B, and 0.005 to 2 parts by weight of at least one compound consisting of a higher aliphatic monocarboxylic acid having 10 to 33 carbon atoms or an ester thereof as a main component, and Surface roughness Ra is [1,001~0
An oriented polyester film having a diameter of 0t-25μm and a coefficient of static friction of 0.6-1.