JPH08336910A - Oriented polyester film - Google Patents

Abstract

PURPOSE: To provide a polyester film of high quality capable of applying to the employment of accelerating a manufacturing line and low-cost components particularly for cost reduction, and having extremely excellent winding property, cutting resistance and scratch resistance. CONSTITUTION: A biaxially oriented polyester film contains 0.01 to 1wt.% silica particles (A) having a mean secondary particle size of 50 to 200nm, mean primary particle size ratio (long size/short size) of 1.25 to 3.0 and the standard deviation of mean primary particle size/primary particle size (d/σ) of 0.5 to 5.0, and 0.01 to 1wt.% inert particles (B) having a mean particle size of 300 to 1500nm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an oriented polyester film. Particularly suitable for magnetic tapes, etc., relates to an oriented polyester film excellent in flat slipperiness, abrasion resistance, scratch resistance, slitting property, winding property, and the like, more specifically, silica particles having a specific shape and particle size distribution. The present invention relates to an oriented polyester film containing: and an inert particle.

[0002]

BACKGROUND OF THE INVENTION Biaxially oriented polyester films represented by polyethylene terephthalate films are widely used for magnetic recording media because of their excellent physical and chemical properties. In this biaxially oriented polyester film, flat slipperiness, abrasion resistance, scratch resistance, slitability, and winding property are major factors that affect the quality of the film manufacturing process and processing process, and the quality of the product. Has become.

For example, in the case of a magnetic tape whose surface is coated with a magnetic coating on a biaxially oriented polyester film, in order to reduce costs in recent years, a coating process, a calendering process, a slitting process, a process of incorporating the magnetic tape into a cassette, and a dubbing process for making a soft tape. In each process such as a process, the feeding speed of the film or tape is increased, resulting in various problems. For example, when the feed speed of the film is increased in the coating step, the film surface comes into contact with the die for coating the magnetic paint, the surface is scraped, and the magnetic powder is streaked by the scraped powder, resulting in a problem that the product yield decreases. is there. Acceleration in the calendering process increases the frequency of cleaning the white powder adhering to the calender rolls, resulting in reduced productivity.

In addition, the speed increase in the slitting process causes the film winding property to be insufficient, resulting in a poor production yield. To improve winding, large particles are generally included to reduce the coefficient of friction between films. However, when speeding up such a film in the slitting process in order to increase productivity, winding disorder occurs due to excessive slipping of the film, and when it is terrible, the film winds around the slitter blade and productivity increases. On the contrary, it gets worse.

In the process of assembling the tape into the cassette, if the tape is incorporated at high speed, shavings and scratches are generated, which causes dropout (information loss). Particularly in VTR applications, an inexpensive metal guide whose surface is not sufficiently finished may be used as the guide post fixed in the cassette for cost reduction. Since the surface of the guide post is extremely rough, it is a conventional technique that improves the slipperiness and abrasion of the film and does not have a back coat (for example, silicon oxide, titanium dioxide, calcium carbonate, talc, clay). , A method of adding inorganic particles such as calcined kaolin (for example, JP-A-54-57562) or a method of precipitating fine particles containing calcium, lithium or phosphorus in the polymerization system (for example, JP-B-52-32).
No. 914)], shavings and scratches are generated in the process of assembling the cassette at high speed, and the number of dropouts is increased.

In order to solve such problems, a method of adding alumina particles having a specific crystal morphology to reduce scratches on the film (for example, Japanese Patent Publication No. 40375/1992) has been proposed. This method has a sufficient effect of improving scratch resistance, but when the alumina particle-containing polyester film is run under heating, the amount of white powder adhering to the metal pin increases. Therefore, for example, if the running speed of the film is increased in the calendar process that receives a heat history, the amount of white powder increases. Further, since alumina has a high hardness, for example, when a high-pressure homogenizer or a media-dispersion wet disintegrator is used to prepare an alumina slurry, SUS, which is the material of these devices, is worn and mixed in the slurry as a contaminant component. . In addition, the frequency with which parts are replaced increases. Further, in the polyester polymerization reaction system to which alumina fine particles are added, there is also a problem that the alumina fine particles scrape off the polyester deterioration products adhering and depositing in the can, especially near the gas-liquid interface, and mix them into the polyester as coarse particles.

There is also a method of adding spherical monodisperse silica obtained by an alkali removal method of sodium silicate or a hydrolysis method of alkoxysilane. In this method, the effect of improving the scratch resistance under high speed running of the film is slightly recognized. However, the particles themselves easily fall off, which deteriorates the abrasion resistance of the film. Further, the particles that have once fallen off tend to be aggregates, and as a result, the scraped material including the aggregates of particles that have fallen off damages the magnetic surface, increasing the number of dropouts.

Further, along with the speeding up in the slitting process, the conventional problems such as shavings of the film and swelling of the cut surface at the time of slitting were further improved, and the continuous slitting property with less friction with the slit blade was also excellent. Films are also desired.

The object of the present invention is to solve the problems that have occurred with the speedup in the magnetic tape manufacturing process and the cassette assembling process, and to improve the smoothness of the flat surface, the slit property, the abrasion resistance, the scratch resistance, and the winding property. It is to provide a high-quality oriented polyester film having excellent properties.

[0010]

That is, according to the present invention, the average secondary particle size is 50 to 200 nm, the average primary particle size ratio (major axis / minor axis) is 1.25 to 3.0, and the average primary particle is 0.01 to 1% by weight of silica particles (A) having a standard deviation (d / σ) of diameter / primary particle diameter of 0.5 to 5.0, and an average particle diameter of 3
0.01 to 100 nm of the inert particles (B)
Biaxially oriented polyester films containing ~ 1 wt% are provided. A more preferred embodiment of the present invention is a biaxially oriented polyester film as described above, wherein the silica particles (A) have a specific surface area of 30 to 80 m ² / g, and the silica particles (A) contain 10 to 500 ppm of chlorine atoms. A film containing, a film in which the inactive particles (B) are at least one of synthetic calcium carbonate particles and heat-resistant organic polymer particles, a film in which the inactive particles (B) have an area ratio of 60% or more to the circumscribed circle, Inert particles (B)
0.05% to 0.5% by weight of the average particle size of the inert particles (B1) having an average particle size of 300 to 650 nm Inert particles having a diameter of 750 to 1300 nm (B
2) 0.01 to 0.25% by weight, a film in which the difference in average particle size between the inert particles (B2) and the inert particles (B1) is 200 to 600 nm, and the intrinsic viscosity of the film is 0. It is a film of 0.5 to 0.6. Further, another embodiment of the present invention comprises silica particles (a) synthesized by a flame hydrolysis method of silicon tetrachloride, having a specific surface area of 30 to 80 m ² / g and an average particle diameter of 50 to 200 nm. More than 01% by weight and less than 0.5% by weight, average particle size is 30
0.05 to 0.5% by weight of synthetic calcium carbonate particles (b) having a particle diameter of 0 to 650 nm, and an average particle diameter of 750 to 13
Synthetic calcium carbonate particles (c) having a size of 00 nm are 0.0
In the oriented polyester film containing 1 to 0.25% by weight, the area ratio of the particles (b) and the particles (c) to the circumscribed circle is 60% in the polyester fium.
The films described above are films having a difference in average particle size of the particles (b) and particles (c) of 200 to 600 nm, and films having an intrinsic viscosity of 0.5 to 0.6.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As the polyester used in the present invention, ethylene terephthalate whose main repeating unit is terephthalic acid and ethylene glycol,
A crystalline polyester such as ethylene naphthalate composed of 2,6-naphthalenedicarboxylic acid and ethylene glycol is preferable. In addition, 8 of the repeating unit of polyester
It is particularly preferable that 0 mol% or more consists of ethylene terephthalate or ethylene naphthalate.

In the above polyester, isophthalic acid, p-β-oxyethoxybenzoic acid, 4,4'-dicarboxylic acid is used as a copolymerization component other than the above components (terephthalic acid, 2,6-naphthalenedicarboxylic acid and ethylene glycol). Diphenyl, 4,4'-dicarboxylbenzophenone, bis- (4-carboxylphenyl)
Dicarboxylic acid components such as ethane, adipic acid, sebacic acid, 5-sodium sulfoisophthalic acid, cyclohexane-1,4-dicarboxylic acid; propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanedimethanol, ethylene oxide of bisphenol A An adduct, a glycol component such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol or the like; an oxycarboxylic acid component such as p-oxybenzoic acid or the like can be arbitrarily selected and used. Furthermore, as a copolymerization component, a small amount of amide bond,
A compound containing a urethane bond, an ether bond, a carbonate bond or the like may be copolymerized.

Polyester is known per se and can be produced by a known method such as condensation reaction of an ester oligomer obtained by a direct esterification method or a transesterification method.

The intrinsic viscosity of the polyester film is 0.5
The value of 0 to 0.60 is suitable as one means for further improving the abrasion resistance, scratch resistance and slit resistance of the film. Here, the intrinsic viscosity is phenol /
The intrinsic viscosity obtained by dissolving a polyester film in a tetrachloroethane mixed solvent (weight ratio: 3/2) and measuring at 30 ° C. The intrinsic viscosity of the polyester film is more preferably 0.52 to 0.58, and particularly preferably 0.54 to 0.56. In order to adjust the intrinsic viscosity of the polyester film to this range, the intrinsic viscosity of the polyester polymer is 0.01 to 0.
02 It is preferable to keep it high.

The silica particles (A) in the present invention are secondary particles having an average particle diameter (according to a sedimentation method, that is, particles having respective particle diameters calculated based on a centrifugal sedimentation curve obtained by a sedimentation method based on Stokes's law of resistance). 50 from the integrated curve of
50% to 200 nm, which means a particle diameter corresponding to wt%,
Average primary particle size ratio [(major axis of primary particle / minor axis of primary particle)
Average value] is 1.25 to 3 and the average primary particle size /
The standard deviation (d / σ) of the primary particle size needs to be 0.5 to 5. The major axis and minor axis of the primary particles when the "average primary particle size ratio" is determined are determined by the method defined below. First, of the distances between any two points on the circumference of the image of the primary particles, the maximum length (absolute maximum length) is the major axis, and the distance (width) of the primary particles in the direction orthogonal thereto is the minor axis. . The diameter (d) of the primary particles when “d / σ” is obtained is the projected area circle equivalent diameter (Haywood diameter). The standard deviation (σ) of the primary particle diameter is the standard deviation of the projected area circle equivalent diameter of the primary particles. The major axis, the minor axis, and the average primary particle diameter of the above-mentioned primary particles of the silica particles (A) are determined by a microscope method. That is, using a scanning electron microscope, the particles 3,
Image analysis is performed for 000 to 5,000 pieces.

The silica particles (A) used in the present invention are
There is no particular limitation on the manufacturing method as long as it has the above characteristics. For example, there is a method of hydrolyzing vapor of silicon tetrachloride with an oxyhydrogen flame (flame hydrolysis method).

According to the flame hydrolysis method, when the reaction conditions are adjusted so that the content of chlorine atoms in the silica particles (A) is 10 to 500 ppm, it is suitable for obtaining silica particles satisfying the above characteristics. is there. When the amount of chlorine atoms in the silica particles (A) is 10 to 500 ppm, there is no risk of corrosion of the SUS tanks and lines for the slurry preparation system and polyester polymerization reaction system, and the particle dispersibility in polyester is also good. is there.

The silica particles (A) in the present invention have an amount of silica which exceeds 99.8% by weight of the constituents.
Also, high-purity silica having an alumina content of less than 0.08% by weight is suitable. The content of alumina in the silica particles is 0.
When it is contained in an amount of 08% by weight or more, particularly 0.2% by weight or more,
When it is added to the polyester polymerization reaction system, a carboxylic acid salt is formed, resulting in significant filter clogging.

The average secondary particle diameter of the silica particles (A) is 50.
It should be ~ 200 nm. Preferably 60 to 1
The thickness is 80 nm, particularly preferably 70 to 150 nm. If the average secondary particle size is less than 50 nm, the fine particles become too fine, and the scratch resistance of the film,
It becomes impossible to form the minute projections necessary for improving the abrasion resistance, while if it is larger than 200 nm, the abrasion resistance deteriorates.

The average primary particle size ratio (major axis / minor axis) of the silica particles (A) must be 1.25 to 3.0.
It is preferably 1.27 to 2.5, and particularly preferably 1.3 to 2.0. When the average primary particle size ratio is less than 1.25, that is, when the particles are close to a perfect circle, the particles do not exhibit stress relaxation in the stretching direction of the film, resulting in voids around the particles. Therefore, when the projections on the film surface are subjected to a shearing force by a roll, a guide or the like, the particles are likely to fall off, and the particles once once fallen into an aggregate to deteriorate the abrasion resistance of the film surface. If the average primary particle size ratio exceeds 3.0, the effect of improving scratch resistance under high speed running becomes insufficient.

Further, the average primary particle diameter of the silica particles (A) /
The standard deviation (d / σ) of the primary particle size needs to be 0.5 to 5.0. This parameter indicates the spread of the particle size distribution of primary particles, and the smaller the number, the broader the particle size distribution. d / σ is 0.5 to 5.0
The use of silica particles improves the slitting property, particularly the continuous slitting property, and even if the slit blade is not changed for a long time at the time of slitting, the generation of cutting chips from the film cutting surface is extremely small, and the film cutting surface also rises. Few. d /
σ is preferably 1.0 to 4.0, and particularly preferably 1.2 to 3.0. If d / σ is less than 0.5, the particle size distribution becomes too wide, and the abrasion resistance of the film deteriorates due to an increase in the amount of coarse particles, which is not preferable. Further, in the case of particles having a substantially uniform particle size such that d / σ exceeds 5.0, the slit property becomes insufficient.

The silica particles (A) must be contained in an amount of 0.01 to 1% by weight based on the polyester film. It is preferably 0.1 to 0.5% by weight. When the content is 0.
If it is less than 01% by weight, the effect of improving scratch resistance and slit property becomes insufficient, while if it exceeds 1% by weight, particles are overlapped and the abrasion resistance is deteriorated.

Further, when the specific surface area of the silica particles (A) by the BET method is 30 to 80 m ² / g, abrasion resistance, scratch resistance and slit property are further improved. The specific surface area is more preferably 35 to 75 m ² / g, 40 to ⁷
0 m ² / g is particularly preferred. Here, the specific surface area by the BET method is physically adsorbed on the powder under the temperature of liquid nitrogen by using the “constant volume method” in which the pressure change associated with adsorption in a constant volume is measured to determine the amount of adsorbed gas. The relationship between the nitrogen gas adsorption amount and the pressure, that is, the so-called "isothermal line" was measured, and the value was obtained from the nitrogen gas adsorption amount on the low pressure side of the isotherm using the BET theory.

The film of the present invention contains silica particles (A) and particles having an average particle size (according to a sedimentation method, that is, particles having respective particle diameters calculated based on a centrifugal sedimentation curve obtained by a sedimentation method based on Stokes's resistance law). 5 from the integrated curve of its abundance
Particle size corresponding to 0% by weight) is 300 to 1500 n
It is necessary to contain the inert particles (B) of m in an amount of 0.01 to 1% by weight based on the polyester film. The silica particles (A) alone have a high friction coefficient for various guides, which not only deteriorates scratch resistance and abrasion resistance but also deteriorates winding property. Product yield is extremely poor. Further, when this is used as a tape film for a magnetic recording medium, the running property of the film is deteriorated.

The average particle size of the inert particles (B) is 300 to 1
It needs to be 500 nm. The average particle size is 300 nm
If it is less than the above range, the effect of improving the winding property becomes insufficient. When the average particle size exceeds 1500 nm, the surface flatness of the film becomes insufficient and the abrasion resistance deteriorates. When a video tape is manufactured from such a film, electromagnetic conversion characteristics are deteriorated and particle dropouts are increased.

The content of the inert particles (B) must be 0.01 to 1% by weight based on the polyester film. If the content of the particles (B) is less than 0.01% by weight, the winding property and the abrasion resistance will be insufficient. When the content of the particles (B) exceeds 1% by weight, the surface smoothness becomes insufficient and the abrasion resistance deteriorates. Furthermore, if the speed is increased in the slitting process, the film will slip too much, resulting in misalignment of the end faces and the film cannot be wound properly.

Examples of the inert particles (B) include synthetic calcium carbonate, heat resistant organic polymer particles, spherical silica, kaolin, zeolite, calcium phosphate, titanium oxide and the like. Among them, at least one selected from synthetic calcium carbonate and heat-resistant organic polymer particles is preferable from the viewpoint of film winding property, abrasion resistance and running property.

A method for producing the synthetic calcium carbonate particles is described in, for example, JP-A-5-117443 and JP-A-6-19.
The method of synthesizing carbon dioxide by blowing carbon dioxide into an aqueous suspension of calcium hydroxide is preferred.

The heat-resistant organic polymer particles are organic polymer particles having a good heat resistance such that the thermal decomposition temperature when the amount is reduced by 10% is 360 ° C. or higher, preferably 380 ° C. or higher. Such heat-resistant organic polymer particles, cross-linked polystyrene particles,
Examples thereof include silicone resin particles, polyimide particles, and PTFE resin [poly (tetrafluoroethylene)] particles.
As the crosslinked polystyrene particles satisfying the above heat resistance, for example, those obtained by the production method described in JP-A-7-238105 are suitable.

As the inactive particles (B), inactive particles (B1) having an average particle size of 300 to 650 nm are used in an amount of 0.05 to 0.5% by weight based on the polyester film, and an average particle size of 750 to 750. 1300 nm inactive particles (B
2) is 0.01 to 0.2 with respect to the polyester film
When it is contained in an amount of 5% by weight, abrasion resistance and slipperiness are further improved, and winding property under high speed running is further improved.
The average particle diameter of the inert particles (B1) is more preferably 350 to 600 nm, particularly preferably 400 to 550 nm.
The content is 0.08 to polyester film
0.45% by weight is more preferable, and 0.15 to 0.40
Weight percent is particularly preferred. The average particle size of the inert particles (B2) is more preferably 800 to 1200 nm,
0 to 1100 nm is particularly preferable. The content thereof is more preferably 0.03 to 0.20% by weight, particularly preferably 0.05 to 0.15% by weight, based on the polyester film.

Inert particles (B2) and inert particles (B1)
It is preferable that the difference in the average particle size from the above is from 200 to 600 nm from the viewpoint of improving the winding property under the condition that the film feeding speed is high, and particularly preferably from 300 to 500.
nm.

The form of the inert particles (B) is preferably close to a lump, a cube, or a sphere from the viewpoint of winding property and running property. Specifically, it is preferable that the "area ratio of the particles to the circumscribing circle" defined by the following formula (I) is 60% or more in terms of abrasion resistance, slipperiness, and winding property. It is particularly preferably 70% or more.

[0033]

[Equation 1]

The particle diameter of the inert particles (B) is preferably close to uniform from the viewpoint of preventing the formation of coarse projections and the deterioration of the abrasion resistance due to the coarse particles. Specifically, the following formula (I
The "dispersion degree of particle size" defined in I) is preferably 50% or less. It is particularly preferably 30% or less.

[0035]

[Equation 2]

When synthetic calcium carbonate particles are used as the inert particles (B), in order to further enhance the affinity between the polyester and the synthetic calcium carbonate particles, it is described, for example, in JP-A-2-178333. The surface of the synthetic calcium carbonate particles to be used is preferably treated with a compound such as a polyether-based acrylic copolymer salt.

The silica particles (A) and the inert particles (B) are preferably added to the polyester polymerization reaction system in the form of a slurry from the viewpoints of particle scattering prevention, supply accuracy and particle dispersibility. It is particularly preferable to add it as a slurry of ethylene glycol. Slurry concentration is 5
20% by weight is suitable.

In the case of dispersion in a slurry form, in order to reduce coarse protrusions on the film surface, known dispersion methods (high-pressure homogeneous dispersion method, media dispersion method, ultrasonic dispersion method, etc.), centrifugation, and filtration. Etc. can be adopted, and it is preferable to use these in combination.

When the silica particles (A) and the inert particles (B) are dispersed in a glycol slurry, a phosphorus element-containing compound such as sodium hexametaphosphate, sodium polyphosphate and ammonium phosphate, tetraethylammonium hydroxide and hydroxylamine. If a dispersant such as a nitrogen atom-containing compound such as an ammonium salt of an acrylic copolymer or an alkaline aqueous solution containing sodium ion, potassium ion or the like is used, the dispersibility of the particles in the slurry and the polymer is further improved. That is, by adding these dispersants, electric charges are generated on the particle surface, the dispersibility of the particles in the slurry and the polymer is further improved, and the generation of coarse particles causing dropout and the like is suppressed.

The addition of the slurry containing the silica particles (A) and the inert particles (B) to the polyester is different for the silica particles (A) and the inert particles (B). In the case of the inert particles (B) other than the spherical silica, it is particularly preferable from the viewpoint of particle dispersibility that the particles are added after the transesterification reaction or after the esterification reaction and before the completion of the initial polycondensation reaction. The time point at which the initial condensation reaction ends means the time point when the intrinsic viscosity of the reaction system reaches about 0.2. After this, since the viscosity of the reaction system is too high, the mixing of the additive components becomes non-uniform and a homogeneous product cannot be obtained. In addition, depolymerization of the oligomer occurs and the productivity is reduced, or the amount of diethylene glycol (DEG), which is a by-product, is increased. On the other hand, when the silica particles (A) and the inert particles (B) are spherical silica, it is preferable to add them at the stage before the start of the transesterification reaction or the start of the esterification reaction from the viewpoint of particle dispersibility.
Particularly preferred is the addition at the stage where the temperature of the reaction vessel is 100 ° C. or lower, which further improves the particle dispersibility in the polymer.

Further, in the film, a group II element of the periodic table is used.
A specific amount of a compound containing a metal atom and a phosphorus compound
If you keep it, if you improve the dispersibility in polyester
In fact, it can lower the melt specific resistance of polyester.
Wear. Specifically, the periodic table for P in phosphorus compounds
Molar ratio of metal atoms in compound containing Group II metal atoms
The (P / metal atom) is preferably 0.5 to 1.0, and 0.
65 to 0.90 is more preferable. Also, in phosphorus compounds
Adjust the P atom content of the to 10 to 2000 ppm
And the particle dispersibility in polyester is good, and the melting ratio is
Resistance is 0.5 × 10 ⁸Obtain polyester with Ω · cm or less
Can be The melt specific resistance of polyester decreases
When melted, melt from the die using electrostatically applied casting method
Stick the extruded polyester sheet to the cooling drum
Contact between the seat and the drum, the pinner
-Rotating cooling without generating bound bubbles called bubbles
Increased ram speed and increased film productivity
can do.

Examples of the compound containing a metal atom of Group II of the periodic table include magnesium acetate, calcium acetate and the like. Examples of the phosphorus compound include phosphoric acid, phosphoric acid triester, acidic phosphoric acid ester, phosphorous acid, and phosphorous acid ester.

As another method of adding the silica particles (A) and the inert particles (B) to the polyester polymerization reaction system, master chips containing the respective particles (A) and (B) in high concentrations are produced, These master chips may be mixed with each other, or the master chip and polyester (bright resin) containing no particles may be appropriately mixed and diluted to adjust the particle concentration to a required level.

The film of the present invention may be a single film, but if the film surface layer (i layer) is the film of the present invention, the recovered product is used as the intermediate layer (ii layer) of a / b / a.
It may be a laminated film composed of layers. The laminated film is preferable in terms of cost reduction. Further, one side of the film of the present invention may be thinly coated with a coating agent containing an aqueous polymer as a film forming component described in JP-A-4-253738 in order to improve the adhesiveness to the magnetic layer. Absent.

The polyester film of the present invention is obtained, for example, by extruding the polyester at a temperature of Tm ° to (Tm + 70) ° C., preferably (Tm + 50) ° C. or less, which is the melting point of the polyester, and obtaining an unstretched film by an electrostatic applied cooling method.
The unstretched film is uniaxially (longitudinal or lateral) at a temperature of (Tg-10) ° C to (Tg + 70) ° C (however, T
g: glass transition temperature of polyester) 2.5 to 5.0
The film is stretched at a draw ratio of twice, and then at a temperature of Tg ° C. to (Tg + 70) ° C. in a direction perpendicular to the above stretching direction (when the first stage stretching is the longitudinal direction, the second stage stretching is the transverse direction) at a temperature of 2.5. ~ 5.
Stretch at a magnification of 0 times. In this case, the area stretching ratio is 9 to
It is preferably 22 times, more preferably 12 to 22 times. The stretching means may be simultaneous biaxial stretching or sequential biaxial stretching.

Further, the obtained film has (Tg + 70)
You may heat-fix at the temperature of ℃ -Tm ℃. For example, for polyethylene terephthalate film, 190-23
It is preferable to heat-fix at 0 ° C. The heat setting time is, for example, 1 to 60 seconds. The parameters of each particle in the film containing the particles (a), (b) and (c),
The production, etc., the characteristics of the film, the production, etc. are in accordance with the film containing the particles (A) and (B) described above.

[0047]

EXAMPLES Next, examples and comparative examples of the present invention will be shown. The present invention is not limited to the examples below. Unless otherwise specified, all parts in the examples and comparative examples mean parts by weight. Further, each characteristic value in the examples and comparative examples is based on the following method.

(1) Average primary particle diameter ratio (major axis / minor axis) of silica particles (A), average primary particle diameter (d) and standard deviation (σ) of primary particle diameter Silica particles (A) It is fixed on a sample stand for a scanning electron microscope, platinum is sputtered, observed with a scanning electron microscope at 10,000 to 50,000 times, and 3,000 to 5,000 pieces with Luzex 2D manufactured by Nireco Corporation. Image analysis of the particles is performed, and the average primary particle diameter ratio (major axis / minor axis), the average primary particle diameter (d), and the standard deviation (σ) of the primary particle diameter are determined.

In the case of calculation from the film, a small sample film is fixed on a sample stage for a scanning electron microscope, and the film surface is attached to the film surface by using a sputtering device (JFC-1100 type ion etching device) manufactured by JEOL Ltd. Ion etching is performed under the following conditions. As for the conditions, the sample was placed in a 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 1.25 mA for about 10 minutes. In addition, platinum film is sputtered on the film surface with the same device, and an observation place is selected with a scanning electron microscope at 10,000 to 50,000 times so that the inactive particles (B) do not enter the same field of view. Made by Luzex 2D Co., Ltd. 3,000
The above-mentioned image analysis is carried out for ˜5,000 particles, and parameters are obtained.

(2) Average particle size of secondary particles of silica particles (A) and average particle size of inactive particles (B) In the case of inactive particles (B), diluted with ethylene glycol and subjected to light transmission type centrifugal sedimentation. Type Particle Size Analyzer (SA-CP3
Type, manufactured by Shimadzu Corporation) is used to measure the particle size distribution. In the case of the secondary particles of silica particles (A), the ethylene glycol slurry is mixed with water at a ratio of 1: 9 (ethylene glycol slurry:
Water, volume ratio) and, if necessary, further dilute with a mixed solution of ethylene glycol and water (ethylene glycol: water = 1: 9, volume ratio). From the integrated curve of particles of each particle size and their abundance calculated from the centrifugal sedimentation curve obtained by the sedimentation method based on the Stokes's resistance law from the sample thus obtained, the particles corresponding to 50% by weight The diameter is the average secondary particle diameter of silica particles (A) and the average particle diameter of inert particles (B).

(3) Specific surface area of silica particles (A) BET was obtained by using Autosorb-1 manufactured by Cantachrome.
The specific surface area is measured by the method.

(4) Area ratio of particles to circumscribed circle At least 100 particles are scanned with a scanning electron microscope (Japanese
Image taken from what was observed and photographed with the vertical S-510 type)
Using an analyzer (Luzex 2D manufactured by Nireco Corporation)
Projected area of each particle (μm²) And circumscribe each particle
Area of circle (μm ²) And obtain the ratio of their averages.
The area ratio (%) of the particle to the circumscribed circle.

[0053]

(Equation 3)

(5) Particle Size Variability At least 100 or more inert particles (B) were measured in the horizontal ferret system by using the apparatus described in (4) above, and the standard deviation and the average value thereof were measured. The ratio is defined as the degree of particle size variation (%).

[0055]

[Equation 4]

(6) Flatness of film surface The film surface was measured using a stylus type three-dimensional surface roughness meter (SE-3AK) manufactured by Kosaka Laboratory under the conditions of a stylus tip radius of 2 μm and a load of 30 mg. 2μ in the longitudinal direction with a cut-off value of 0.25 mm and a measurement length of 1 mm
Quantization width of 0.00312μ
It is taken in by the external recording device with m. Such a measurement is continuously performed at a 2 μm interval in the transverse direction of the film for 150 times.
One time, that is, over a width of 0.3 mm in the lateral direction of the film. The three-dimensional centerline average surface roughness (SRa: nm) measured under these conditions is defined as the flatness of the film surface.

(7) Coefficient of Friction According to ASTM D-1894-63, the dynamic friction coefficient (μd) between films is measured using a thread type slip tester under environmental conditions of 23 ° C. and 65 RH%.

(8) Winding property in slitter The winding patterns (wrinkles and winding disorder) when winding the film in the slitting process are ranked as follows.

<Judgment of winding shape> ⊚: No winding wrinkles and winding irregularities even at a film winding speed of 500 m / min. ○: Some winding wrinkles or winding irregularities when the film winding speed is 500 m / min. There is no wrinkle or winding disorder when decelerating to 400 m / min. X: When the film winding speed is 400 m / min, there is some wrinkling or disorder, but when decelerating to 350 m / min, wrinkling. And winding disorder does not occur at all XX: Wrinkling or disorder occurs even when the film winding speed is reduced to 350 m / min.

(9) Scraping resistance Using the film running tester shown in FIG. 1, the scraping resistance is evaluated. In FIG. 1, 1 is a film, 2 is a capstan, 3 is a tension detecting device, 4 is a fixed guide pin (commercially available VT).
Fixed guide pin for R: maximum protrusion height measured with a stylus type surface roughness meter is 0.15 μm, center line average surface roughness is 0.0
08 μm).

A 1/2 inch width slit polyester film which had been heat-treated at 130 ° C. for 1 hour in a hot air dryer was cooled to room temperature (23 ° C.) in an atmosphere of 23 ° C. and 65 RH%, and then 23 ° C. and 65 RH. %, Contact the fixed guide pin 4 at an angle of 135 ° under a 50% tension.
While running, run 90 m at a speed of 200 cm / min. After running, the amount of white powder adhering to the surface of the fixed guide pin 4 is observed with a real-time microscope and ranked as follows.

<Judgment of amount of white powder> ◎: White powder is not attached or there is only a small amount of white powder ○: White powder is thinly attached ×: A large amount of white powder is partially attached × ×: A large amount of white powder is spread over the entire surface Adhesion ○ If above, there is no practical problem

(10) Scratch resistance In the running tester shown in FIG. 1 used in the abrasion resistance test, a polyester film slit to a 1/2 inch width which has not been heat-treated is used at 23 ° C. and 65 RH. %
In the atmosphere of, as the fixed guide pin 4, instead of the fixed guide pin 4 for the commercially available VTR used in the abrasion resistance test,
Using a fixing pin (center line average surface roughness of 0.15 μm) that is formed by bending a SUS sintered plate into a cylindrical shape and has an insufficient surface finish,
Contact them at an angle of 90 ° and give 1 g of tension 100g.
Run 90 m at 27 cm / sec. After the running film was vapor-deposited with aluminum, the entire width of the film was observed with a real microscope while shining light obliquely, and the number of scratches on the film surface was ranked as follows. The number of scratches that are shallow and those that are not continuous are also included in the number.

<Determination of Number of Scratches> A: 10 lines or less / full width O: 11 to 30 lines / full width X: 31 to 60 lines / full width XX: 61 lines or more / full width

(11) Slitting A polyester film is slit by a shear cutter to a width of 1/2 inch for 1000 m, and the slit portion of the film is visually observed. The degree of beard and powder generation is ranked as follows.

<Judgment of Slitting Properties> ◎: Very few beards and powders ○: Little beards and powders △: Normal level of beards and powders ×: Slightly beards and powders × X: Most of beards and powders are generated, and the level of slit property of the commercially available biaxially oriented polyester film for video tapes is mostly Δ or ×.

Example 1 A silica particle (A) -containing polyester was obtained by the following method.
While cooling the esterification reaction can, terephthalic acid was added to 86.
4 parts of ethylene glycol and 64.4 parts of ethylene glycol were charged, and while stirring, 0.03 part of antimony trioxide, 0.088 part of magnesium acetate tetrahydrate and 0.16 part of triethylamine were charged as a catalyst. Waited until the temperature was cooled to 80 ° C. On the other hand, the average primary particle size ratio (major axis / minor axis) is 1.35, the average primary particle size / standard deviation of the primary particle size is 2.5, the BET specific surface area is 50 m ² / g, and the chlorine atom content is 50 ppm. Silica particles (A) obtained by a flame hydrolysis method of a certain silicon tetrachloride were mixed in ethylene glycol, and the slurry was subjected to wet disintegration treatment, centrifugal separation treatment and filtration treatment to obtain an average secondary particle diameter of 110 nm. An ethylene glycol slurry of silica particles (A) was obtained. After the temperature inside the esterification reaction can reaches 80 ° C., the slurry (particle content: 2.0 with respect to 100 parts of the produced polymer) is used.
Part) was added to the esterification reaction can, and after 5 minutes, the temperature was increased by pressurization, and the pressure esterification reaction was performed under the conditions of a gauge pressure of 3.5 kg / cm ² and 240 ° C. Then, the pressure inside the esterification reaction vessel was returned to normal pressure, and 0.033 part of trimethyl phosphate was added. Five minutes after the addition of trimethyl phosphate, the esterification reaction product was transferred to a polycondensation reaction vessel and subjected to a polycondensation reaction under reduced pressure at 280 ° C. to obtain a polyester having an intrinsic viscosity of 0.58. This is referred to as polyester (A).

Further, a polyester containing inert particles (B1) and a polyester containing inert particles (B2) were obtained by the following method. When the temperature of the esterification reactor was raised to 200 ° C., 86.4 parts of terephthalic acid and 64.4 parts of ethylene glycol were charged, and 0.03 parts of antimony trioxide and acetic acid were used as a catalyst while stirring. Magnesium 4
0.088 parts of the hydrate and 0.16 parts of triethylamine were added. Next, pressurization and temperature increase are performed and the gauge pressure is 3.5k.
The pressure esterification reaction was carried out under the conditions of g / cm ² and 240 ° C. Thereafter, the pressure inside the esterification reaction vessel was returned to normal pressure, and 0.040 part of trimethyl phosphate was added. 260 ° C
15 minutes after the temperature was raised and trimethyl phosphate was added, centrifugation treatment was carried out, and an aqueous sodium tripolyphosphate solution was added as a dispersant to calcium carbonate so as to be 0.1% by weight as Na atom, and externally added. A calcite-type synthetic calcium carbonate particle (B having an area ratio to a circle of 80%, a particle size variation of 28%, and an average particle size of 510 nm) (B
The ethylene glycol slurry (1) (particle content: 2.0 parts based on 100 parts of the produced polymer) was added. 15
After the elapse of minutes, the obtained esterification reaction product was transferred to a polycondensation reaction vessel and subjected to a polycondensation reaction under reduced pressure at 280 ° C. to obtain a polyester having an intrinsic viscosity of 0.58. This is made into polyester (B1).

In the production of the polyester (B1), instead of the calcite type synthetic calcium carbonate particles (B1) having an average particle diameter of 510 nm, the area ratio to the circumscribed circle is 75%, the degree of particle size variation is 25%, and Average particle size 89
0 nm calcite-type synthetic calcium carbonate particles (B2)
Except that a slurry (containing 2.0 parts per 100 parts of the polymer produced) containing
Polyester having an intrinsic viscosity of 0.58 was obtained in the same manner as in the production method 1). This is made into polyester (B2).

In the production of the polyester (B1), silica particles and silica particles were prepared in the same manner as in the production of the polyester (B1) except that the calcite-type synthetic calcium carbonate particles (B1) having an average particle diameter of 510 nm were not added. A polyester with an intrinsic viscosity of 0.58 was obtained, containing no inert particles. This is referred to as polyester (C).

Polyester (A), (B1), (B2)
And (C) were mixed in a weight ratio of 20: 10: 3.75: 66.25, dried and melt-extruded at 290 ° C., and an unstretched sheet was brought into close contact with the cooling drum by an electrostatic applied casting method, then 90 The film was stretched 3.6 times in the machine direction at 0 ° C and 3.7 times in the cross direction at 110 ° C. Then heat treat at 220 ℃,
A biaxially oriented polyester film having a thickness of 14.5 μm and an intrinsic viscosity of 0.56 was obtained.

Comparative Example 1 The polyester (A) used in Example 1 was not used, and the polyesters (B1), (B2) and (C) were mixed at 10: 3.
Example 1 except mixing in a weight ratio of 75: 86.25
A film having the same thickness and intrinsic viscosity as the film obtained in Example 1 was obtained in the same manner as in.

Comparative Example 2 Polyesters (A), (B1), (B2) and (C) were mixed in the same manner as in Example 1 except that the weight ratio was 70: 10: 3.75: 16.25. A film having the same thickness and intrinsic viscosity as the film obtained in Example 1 was obtained. In Comparative Example 2, the content of silica particles (A) is 1.4% by weight.
Met.

Comparative Example 3 The silica particles (A) used in Example 1 were synthesized by changing the reaction conditions of the flame hydrolysis method of silicon tetrachloride. That is, the average primary particle size ratio (major axis / minor axis) is 1.30, the average primary particle size / standard deviation of primary particle size is 6.0, and the BET specific surface area is 20.
Silica particles having an average secondary particle size of 110 nm are obtained by mixing silica particles having a chlorine atom content of 0 m ² / g and a chlorine atom content of 30 ppm in ethylene glycol, and subjecting the slurry to wet crushing, centrifugal separation and filtration. A polyester (A2) was obtained in the same manner as in the production method of the polyester (A) of Example 1, except that the ethylene glycol slurry of was used instead of the silica particles (A) of Example 1. A film having the same thickness and intrinsic viscosity as the film obtained in Example 1 was obtained in the same manner as in Example 1 except that polyester (A2) was used instead of polyester (A).

Comparative Example 4 Sodium silicate was used as a raw material and was produced by a method of removing the alkali (sodium) content in a wet system. The average particle size was 110 nm and the average primary particle size ratio (major axis / minor axis) was 1.0
5, average primary particle size / standard deviation of primary particle size is 20, BET
Polyester of Example 1 except that spherical monodisperse colloidal silica particles having a specific surface area of 30 m ² / g and a chlorine atom content of less than 1 ppm were used instead of the silica particles (A) used in Example 1. Polyester (A3) was obtained in the same manner as in the production method (A). A film having the same thickness and intrinsic viscosity as the film obtained in Example 1 was obtained in the same manner as in Example 1 except that polyester (A3) was used instead of polyester (A).

Comparative Example 5 An average primary particle size ratio (major axis / minor axis) of 1.05, which was produced by a method of removing alkali (sodium) from a sodium silicate as a raw material in a wet system, and chlorine atom Content rate is 1
Average particle size of less than ppm, 30 nm, 50 nm, 8
Five types of spherical monodisperse colloidal silica particles of 0 nm, 110 nm and 140 nm were mixed, and the average particle size after mixing was 80 nm, and the standard deviation of the average primary particle size / primary particle size was 2.
5. Same as the production method of polyester (A) in Example 1 except that spherical colloidal silica having a wide BET specific surface area of 50 m ² / g and a wide particle size distribution is used instead of the silica particles (A) used in Example 1. To obtain polyester (A4). Instead of polyester (A), polyester (A
Example 1 was repeated in the same manner as in Example 1 except that 4) was used.
A film having the same thickness and intrinsic viscosity as the film obtained in 1. was obtained.

Comparative Example 6 Silica particles (A) synthesized by the flame hydrolysis method of silicon tetrachloride described in Example 1 were mixed in ethylene glycol (average secondary particle size of silica particles: 250 nm) to prepare the slurry. A polyester (A5) is obtained in the same manner as in the production method of the polyester (A) in Example 1 except that the slurry is added as it is to the esterification reaction vessel without performing wet crushing treatment, centrifugation treatment and filtration treatment. It was A film having the same thickness and intrinsic viscosity as the film obtained in Example 1 was obtained in the same manner as in Example 1 except that polyester (A5) was used instead of polyester (A).

Example 2 Instead of the synthetic calcium carbonate particles having an average particle size of 510 nm in the polyester (B1) used in Example 1, the area ratio to the circumscribed circle was 80% and the degree of particle size variation was 27.
% And a calcite-type synthetic calcium carbonate particle (B1a) having an average particle diameter of 420 nm was used to obtain a polyester (B1a) in the same manner as in the production method of the polyester (B1) in Example 1. In addition, the polyester (B
In place of the synthetic calcium carbonate particles having an average particle diameter of 890 nm in 2), a calcite-type synthetic calcium carbonate particle having an area ratio to the circumscribing circle of 80%, a degree of particle diameter variation of 23%, and an average particle diameter of 790 nm ( A polyester (B2a) was obtained in the same manner as in the production method of the polyester (B2) in Example 1 except that B2) was used. Polyester (A), (B1a), (B2a), (C) 15: 1
A film having the same thickness and intrinsic viscosity as the film obtained in Example 1 was obtained in the same manner as in Example 1 except that the film was mixed in a weight ratio of 5: 5: 65.

Comparative Example 7 Polyester (A), (B1a), (B2a), (C)
A film having the same thickness and intrinsic viscosity as the film obtained in Example 2 was obtained in the same manner as in Example 2 except that was mixed at a weight ratio of 15: 60: 5: 20.

Comparative Example 8 A process for producing the polyester (B1a) of Example 2 was repeated except that the average particle size of the synthetic calcium carbonate particles (B1a) in the polyester (B1a) used in Example 2 was changed from 420 nm to 200 nm. Similarly, polyester (B1
b) was obtained. Use polyester (B1b) instead of polyester (B1a), and use polyester (B2
A film having the same thickness and intrinsic viscosity as the film obtained in Example 2 was obtained in the same manner as in Example 2 except that a) was not used.

Comparative Example 9 In the polyester (B2a) used in Example 2,
The average particle size of synthetic calcium carbonate particles (B2a) is 790
Polyester (B2b) was obtained by the same production method as that of the polyester (B2a) of Example 2 except that the variation degree of the particle size was changed from 23% to 1600 nm and from 23% to 45%. The same thickness and intrinsic viscosity as the film obtained in Example 2 were obtained in the same manner as in Example 2 except that the polyester (B2b) was used instead of the polyester (B2a) and the polyester (B1a) was not used. Was obtained.

Example 3 In the polyester (B1a) used in Example 2, the area ratio of the synthetic calcium carbonate particles (B1a) to the circumscribed circle was changed from 80% to 55%, and the degree of particle size variation was 27.
% To 45%, except that the polyester (B1a) was produced in the same manner as in Example 2.
c) was obtained. A film having the same thickness and intrinsic viscosity as the film obtained in Example 2 was obtained in the same manner as in Example 2 except that polyester (B1c) was used instead of polyester (B1a).

Example 4 A polyester (B1a) was prepared in the same manner as in Example 2 except that the average particle size of the synthetic calcium carbonate particles (B1a) in the polyester (B1a) used in Example 2 was changed to 650 nm. To obtain polyester (B1d). A film having the same thickness and intrinsic viscosity as the film obtained in Example 2 was obtained in the same manner as in Example 2 except that the polyester (B1d) in Example 2 was used in place of the polyester (B1d).

Example 5 Instead of the calcite-type synthetic calcium carbonate particles (B1a) in the polyester (B1a) used in Example 2,
A polyester (B1e) was produced in the same manner as in the production method of the polyester (B1a) of Example 2 except that vaterite-type spherical synthetic calcium carbonate particles having an area ratio to the circumscribing circle of 95% and a particle size variation of 15% were used. Obtained. A film having the same thickness and intrinsic viscosity as the film obtained in Example 2 was obtained in the same manner as in Example 2 except that the polyester (B1e) in Example 2 was used instead of the polyester (B1e).

Example 6 The average particle size of the synthetic calcium carbonate particles (B2a) in the polyester (B2a) used in Example 2 was 750 nm.
In the same manner as in the production method of the polyester (B2a) of Example 2, except that the area ratio to the circumscribed circle was changed to 77% and the degree of particle size variation was changed to 26%.
c) was obtained. The same thickness as the film obtained in Example 2 was obtained in the same manner as in Example 2 except that the polyester (B2c) was used instead of the polyester (B2a) in Example 2 and the polyester (B1a) was not used. A film having a smoothness and an intrinsic viscosity was obtained.

Example 7 The silica particles (A) used in Example 1 were synthesized by changing the reaction conditions of the flame hydrolysis method of silicon tetrachloride. Average primary particle size ratio (major axis / minor axis) is 1.32, average primary particle size / standard deviation of primary particle size is 3.0, and BET specific surface area is 76 m ² /
g, silica particles having a chlorine atom content of 130 ppm are mixed in ethylene glycol, and the slurry is subjected to wet disintegration treatment, centrifugal separation treatment and filtration treatment to obtain ethylene glycol of silica particles having an average secondary particle diameter of 90 nm. A polyester (A6) was obtained in the same manner as in the polyester (A) of Example 1, except that the slurry was used instead of the silica particles (A) of Example 1. Instead of the synthetic calcium carbonate particles (B1) having an average particle diameter of 510 nm in the polyester (B1) used in Example 1, an area ratio of 96% to the circumscribed circle and an average particle diameter variation of 12% Pyrolysis temperature is 383 ° C when the particle size is 450 nm and weight loss is 10%
Crosslinked polystyrene particles [Synthetic Rubber Co., Ltd., S
2467 (A)] was used, and the polyester (B1) was produced in the same manner as in the production method of the polyester (B1) of Example 1.
f) was obtained.

Polyester (A6), (B1f), (B
2a) and (C) were mixed in a weight ratio of 15: 15: 5: 65, dried, melt-extruded at 290 ° C., and wound on a cooling drum by an electrostatic cast method to prepare an unstretched sheet. Then, the peripheral speed difference of the roll was changed in the machine direction, and the film was stretched in two stages of 1.36 times at 123 ° C. and 3.23 times at 127 ° C. This uniaxially stretched film was divided into three steps in the transverse direction by using a stenter, and 1.94 at 118 ° C.
2 times, 1.47 times at 123 ° C., 1.32 times at 130 ° C., further heat treated with hot air at 204 ° C. under slight stretching of 1.09 times, and then 2.4 at the same temperature in the transverse direction. % Relaxation. After cooling once, the roll speed difference of 12
A thickness of 14.5 was obtained by giving 0.8% relaxation in the longitudinal direction at 5 ° C, cooling it as it is, cooling it to room temperature, and winding it.
A biaxially oriented polyester film having a μm and an intrinsic viscosity of 0.56 was obtained.

Example 8 In Example 7, polyesters (A6) and (B1
f), (B2a) and (C) have an intrinsic viscosity of 0.6
4 polyester (A7), (B1g), (B2
d) and (C1) were produced in the same manner as in Example 7. Polyester (A6), (B1f), (B2) of Example 7
Instead of a) and (C), polyesters (A7) and (B1
Example 7 except that g), (B2d) and (C1) were used.
A film having the same thickness as the film obtained in Example 7 and an intrinsic viscosity of 0.62 was obtained in the same manner as in.

Example 9 Instead of the crosslinked polystyrene particles [S2467 (A)] having an area ratio of 96% with respect to the circumscribed circle in the polyester (B1f) used in Example 7 and having an average particle diameter of 450 nm, the area ratio with respect to the circumscribed circle was used. Is 94% and the degree of variation in particle size is 1
Production method of polyester (B1f) of Example 7 except that silicon resin particles (Tospearl 105, manufactured by Toshiba Silicone Co., Ltd.) having a thermal decomposition temperature of 600 ° C. at a 10% weight loss of 6% with an average particle diameter of 500 nm are used. A polyester (B1g) was obtained in the same manner as in. A film having the same thickness and intrinsic viscosity as the film obtained in Example 7 was obtained in the same manner as in Example 7 except that polyester (B1g) was used instead of the polyester (B1f) in Example 7. .

Example 10 Polyesters (A1), (B1) used in Example 1,
20: 10: 3.75: 66.25 for (B2) and (C)
Was mixed at a weight ratio of 2, dried, melt-extruded at 290 ° C., and wound on a cooling drum by an electrostatic cast method to prepare an unstretched sheet. Then use a stenter to move 2
Divided into stages, 1.20 times at 93 ℃, 3.15 at 87 ℃
The film was stretched twice. This uniaxially stretched film is IR
It was heated by a heater and stretched 4.02 times in the machine direction due to the difference in peripheral speed between the low speed roll and the high speed roll. Then 1.
The film was heat-treated with hot air at 200 ° C. under a slight stretch of 01 times, and then 1.0% was relaxed in the transverse direction at the same temperature. After cooling once, 0.6% relaxation was given in the longitudinal direction at 115 ° C. due to the difference in the peripheral speed of the roll, and the film was cooled to room temperature and wound up to have a thickness of 9.5 μm and an intrinsic viscosity of 0.56. A biaxially oriented polyester film of was obtained. The film obtained in this example was particularly suitable for a video tape for long-time recording such as E300.

Example 11 A dimethyl naphthalene-2,6-dicarboxylate 100 was placed in a transesterification reactor equipped with a stirrer, a rectification column and a condenser.
Parts and 52 parts of ethylene glycol were charged, and 0.06 parts of magnesium acetate tetrahydrate was charged while stirring. Waiting until the temperature of the transesterification reactor was cooled to 80 ° C. After the temperature inside the transesterification reaction can reached 80 ° C., an ethylene glycol slurry of silica particles (A) used in Example 1 (particle content: 2.0 parts based on 100 parts of the produced polymer) was added. Then, the temperature was gradually raised to 180 to 240 ° C., and the methanol produced at the same time was continuously distilled out of the reaction system to carry out the transesterification reaction. After the completion of the transesterification reaction, 0.03 part of antimony trioxide as a polycondensation catalyst and 0.03 part of trimethyl phosphate as a heat-resistant stabilizer were added, and subsequently the temperature was raised to 290 ° C. while continuously distilling ethylene glycol. , At the same time 0.
The pressure was reduced to 2 mmHg to carry out a polycondensation reaction to obtain a polyethylene-2,6-naphthalate composition [polyester (A7)] having an ultimate concentration of 0.58.

In the production of polyester (A7), an ethylene glycol slurry containing the synthetic calcium carbonate particles (B1) used in Example 1 instead of the silica particles (A) (particle content: 2 per 100 parts of the polymer produced). ．
(0 part), the calcium carbonate (B1) slurry was added after the transesterification reaction, and after 10 minutes, antimony trioxide and trimethyl phosphate were added in the same manner as in the production method of the polyester (A7) above, except that Viscosity 0.58
To obtain a polyethylene-2,6-naphthalate composition (polyester (B1h)).

Furthermore, in the production of the polyester (A7), an ethylene glycol slurry of the synthetic calcium carbonate particles (B2) used in Example 1 instead of the silica particles (A) (particle content: 100 parts of the polymer produced). 2.0 parts), and the calcium carbonate (B2) slurry is added after the transesterification reaction, and after 10 minutes, antimony trioxide and trimethyl phosphate are added in the same manner as in the above polyester (A7). Thus, a polyethylene-2,6-naphthalate composition [polyester (B2e)] having an intrinsic viscosity of 0.58 was obtained.

On the other hand, in the production of the polyester (A7), a polyethylene-2,6-naphthalate composition having an intrinsic viscosity of 0.58, which does not contain silica particles (A) and does not contain silica particles or inert particles, is used. Polyester (C
2)] was obtained.

Polyester (A7), (B1h), (B
2e) and (C2) at 20: 10: 3.75: 66.25
In the weight ratio of, melted and extruded at 300 ℃ after drying,
An unstretched sheet was prepared by winding on a cooling drum by an electrostatic applied casting method. This unstretched sheet was stretched 5 times in the longitudinal direction at 130 ° C. and then 4 times in the transverse direction, and then 210 ° C.
Then, a biaxially oriented polyester film having a thickness of 9.5 μm and an intrinsic viscosity of 0.56 was obtained. The film obtained in this example is particularly suitable for a video tape for long-time recording such as E300.

Properties of the polyester films obtained in Examples 1 to 11 and Comparative Examples 1 to 9 are shown in Tables 1 to 5.

[0097]

[Table 1]

[0098]

[Table 2]

[0099]

[Table 3]

[0100]

[Table 4]

[0101]

[Table 5]

As is clear from the results of Tables 1 to 5, the film of the present invention is good in any of flat slipperiness, winding property, abrasion resistance, scratch resistance and slit property, and has high quality. Met.

Example 12 A silica particle (a) -containing polyester was obtained by the following method.
While cooling the esterification reaction can, terephthalic acid was added to 86.
Charge 4 parts and 64.4 parts of ethylene glycol, and while stirring, charge 0.03 part of antimony trioxide and 0.088 part of magnesium acetate tetrahydrate and 0.16 part of triethylamine as a catalyst. Was cooled to 80 ° C. On the other hand, silica particles obtained by the flame hydrolysis method of silicon tetrachloride were mixed in ethylene glycol, and the slurry was subjected to wet disintegration treatment and centrifugal separation treatment to obtain a BET specific surface area of 50 m ² / g and an average particle diameter of 50 m ² / g. 110
An ethylene glycol slurry of silica particles of nm was obtained. After the temperature inside the esterification reaction can reaches 80 ° C., the above slurry (particle content: 2.0 parts with respect to 100 parts of produced polymer) is added to the esterification reaction can, and after 5 minutes, the pressure is increased. The temperature is raised and the gauge pressure is 3.5 kg / cm ² , 24
The pressure esterification reaction was carried out under the condition of 0 ° C. The pressure inside the esterification reaction vessel was returned to normal pressure, and 0.033 part of trimethyl phosphate was added. Five minutes after the addition of trimethyl phosphate, the esterification reaction product was transferred to a polycondensation reactor and heated at 280 ° C.
The polycondensation reaction is performed under reduced pressure to obtain an intrinsic viscosity (intrinsic viscosity) of 0.
58 polyesters were obtained. This is polyester (a)
And

The polyester containing the synthetic calcium carbonate particles (b) was obtained by the following method. When the temperature of the esterification reactor was raised to 200 ° C, terephthalic acid was added to
Charged 6.4 parts and 64.4 parts of ethylene glycol,
While stirring, 0.03 of antimony trioxide was used as a catalyst.
Parts and 0.088 parts of magnesium acetate tetrahydrate and 0.16 parts of triethylamine were added. Then, the temperature was increased by pressurization, and the pressure esterification reaction was performed under the conditions of a gauge pressure of 3.5 kg / cm ² and 240 ° C. Thereafter, the pressure inside the esterification reaction vessel was returned to normal pressure, and 0.040 part of trimethyl phosphate was added. After further raising the temperature to 260 ° C. and adding trimethyl phosphate 15 minutes later, centrifugation was carried out, and a sodium tripolyphosphate aqueous solution was added as a dispersant so as to be 0.1 wt% as Na atoms to calcium carbonate. And an ethylene glycol slurry of calcite type synthetic calcium carbonate particles (b) having an area ratio to the circumscribed circle of 80% and an average particle size of 510 nm (particle content: 2.0 parts based on 100 parts of the produced polymer). did. 1
After 5 minutes, the obtained esterification reaction product was transferred to a polycondensation reaction vessel and subjected to polycondensation reaction under reduced pressure at 280 ° C. to obtain a polyester having an intrinsic viscosity of 0.58. This is referred to as polyester (b).

On the other hand, in the production of the above polyester (b), instead of the calcite-type synthetic calcium carbonate particles (b) having an average particle diameter of 510 nm, the calcite having an area ratio to the circumscribed circle of 75% and an average particle diameter of 890 μm. A polyester having an intrinsic viscosity of 0.58 was obtained, which contained a slurry of the type synthetic calcium carbonate particles (c) (particle content: 2.0 parts based on 100 parts of the produced polymer). This is referred to as polyester (c).

Further, in the production of the polyester (b), the addition of the calcite type synthetic calcium carbonate particles (b) having an average particle diameter of 0.5 μm was stopped, and a polyester having an intrinsic viscosity of 0.58 containing no added fine particles was added. Obtained.
This is referred to as polyester (d).

Polyester (a), (b), (c),
(D) was mixed in a weight ratio of 20: 10: 3.75: 66.25, dried and melt-extruded at 290 ° C., longitudinally multiplied by 3.6 at 90 ° C., and laterally 3.7 at 110 ° C. It was stretched twice. Then, it was heat-treated at 220 ° C. to obtain a biaxially oriented polyester film having a thickness of 14.5 μm and an intrinsic viscosity of 0.56.

Comparative Example 10 Polyesters (b), (c) and (d) were mixed at 10: 3 without using the polyester (a) containing the silica particles (a) synthesized by the flame hydrolysis method of silicon tetrachloride. .75: 8
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 12 except that the weight ratio was 6.25.

Comparative Example 11 Polyester (a), (b), (c), (d) 70:
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 12 except that the weight ratio was 10: 3.75: 16.25.

Comparative Example 12 Instead of the silica particles synthesized by the flame hydrolysis method of silicon tetrachloride, sodium silicate was used as a raw material, and the alkali (sodium) component was removed by a wet system to produce a comparative sample. Surface area is 50 m ² / g and average particle size is 110 n
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 12 except that an ethylene glycol slurry of m colloidal silica particles was used.

Comparative Example 13 The same thickness and intrinsic viscosity were obtained as in Example 12 except that particles having a specific surface area of 200 m ² / g were used as silica particles synthesized by the flame hydrolysis method of silicon tetrachloride. A film having was obtained.

Comparative Example 14 The same thickness and intrinsic viscosity were obtained in the same manner as in Example 12 except that particles having a specific surface area of 25 m ² / g were used as silica particles synthesized by the flame hydrolysis method of silicon tetrachloride. Was obtained.

Comparative Example 15 As silica particles synthesized by the flame hydrolysis method of silicon tetrachloride, particles having an average particle size of 250 nm were used, except that
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 12.

Comparative Example 16 The same thickness and intrinsic viscosity were obtained in the same manner as in Example 12 except that particles having an average particle diameter of 30 nm were used as silica particles synthesized by the flame hydrolysis method of silicon tetrachloride. I got a film.

Comparative Example 17 The use of polyester (b) was stopped, and polyesters (a), (c) and (d) were mixed at 20: 3.75: 76.25.
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 12 except that the film was mixed in the weight ratio of.

Example 13 In the polyester (b) of Example 12, instead of the synthetic calcium carbonate particles having an average particle diameter of 510 nm, a calcite-type synthetic carbonate having an area ratio of 80% to the circumscribed circle and an average particle diameter of 420 nm was used. A polyester (b2) was obtained by the same production method as the polyester (b) of Example 1 except that calcium particles were used as the particles (b). Example 12
The average particle size of the polyester (c) is 890 nm
Polyester (c) of Example 12 except that calcite-type synthetic calcium carbonate particles having an area ratio to the circumscribed circle of 80% and an average particle size of 790 nm are used as the particles (c) instead of the synthetic calcium carbonate particles. Polyester (c2) was obtained by the same production method as described above. Polyester (a),
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 12 except that (b2), (c2) and (d) were mixed in a weight ratio of 15: 15: 5: 65.

Comparative Example 18 Polyester (c2) was stopped, polyester (a),
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that (b2) and (d) were mixed in a weight ratio of 15:15:70.

Comparative Example 19 Polyesters (a), (b2), (c2) and (d) were used as 1
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that the mixture was carried out at a weight ratio of 5: 35: 5: 45.

Comparative Example 20 Polyesters (a), (b2), (c2) and (d) were used as 1
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that the mixture was carried out at a weight ratio of 5: 15: 20: 50.

Comparative Example 21 In the polyester (b2) of Example 13, the synthetic calcium carbonate particles (b) have an average particle diameter of 420 nm to 20 nm.
A polyester (b3) was obtained by the same production method as that of the polyester (b2) of Example 13 except that the thickness was changed to 0 nm.
Polyester (b3) instead of polyester (b2)
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that was used.

Comparative Example 22 In the polyester (c) of Example 12, only the average particle size of the synthetic calcium carbonate particles (c) was changed from 890 nm to 1
A polyester (c3) was obtained in the same manner as the polyester (c) in Example 12 except that the thickness was changed to 600 nm.
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that the polyester (c3) was used instead of the polyester (c).

Example 14 In the polyester (b2) of Example 13, only the area ratio to the circumscribed circle of the synthetic calcium carbonate particles (b) was 8
A polyester (b4) was obtained by the same production method as the polyester (b2) of Example 13 except that the content was changed from 0% to 55%. A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that the polyester (b4) was used instead of the polyester (b2).

Example 15 Polyester (b2) of Example 13 was prepared in the same manner as polyester (b2) of Example 13 except that the average particle size of synthetic calcium carbonate particles (b) was changed to 650 nm. b5) was obtained. A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that the polyester (b5) in Example 13 was used in place of the polyester (b5).

Example 16 In the polyester (b2) of Example 13, the area ratio to the circumscribed circle was 9 as the synthetic calcium carbonate particles (b).
A film having the same thickness and intrinsic viscosity was obtained in the same manner as in Example 13 except that 5% of vaterite-type spherical synthetic calcium carbonate particles was used. Examples 12 to 1 above
6, the characteristics of the polyester films obtained in Comparative Examples 10 to 22 are shown in Tables 6 and 7.

[0125]

[Table 6]

[0126]

[Table 7]

As is clear from the results of Tables 6 and 7, the film of the present invention is excellent in flat slipperiness, winding property, abrasion resistance and scratch resistance, and is of high quality.

[0128]

The oriented polyester film of the present invention is
Specific average secondary particle size, average primary particle size ratio (major axis / minor axis),
It contains a specific amount of silica particles (A) having an average primary particle diameter / standard deviation of primary particles and inert particles (B) having a specific average particle diameter. Therefore, it can be applied to high-speed film or tape feeding in the production line, which is performed to reduce the cost of tapes, and to adopt inexpensive parts. Wrapability, abrasion resistance, scratch resistance, and slitability It is a very high quality polyester film. The polyester film can be preferably used as a base film for a magnetic recording medium.

[Brief description of drawings]

FIG. 1 is a schematic view of a running tester for evaluating abrasion resistance and scratch resistance.

[Explanation of symbols]

 1 film 2 capstan 3 tension detector 4 fixed guide pin

Claims (13)

[Claims] 1. An average secondary particle diameter of 50 to 200 nm, an average primary particle diameter ratio (major axis / minor axis) of 1.25 to 3.0, and an average primary particle diameter / standard deviation of primary particle diameter (d / σ) is 0.5 to
0.01 to 1% by weight of silica particles (A) of 5.0,
And a biaxially oriented polyester film containing 0.01 to 1% by weight of the inert particles (B) having an average particle diameter of 300 to 1500 nm. 2. The specific surface area of the silica particles (A) is 30 to 8.
The oriented polyester film according to claim 1, which has an amount of 0 m ² / g. 3. Silica particles (A) are 10 to 500 ppm
The oriented polyester film according to claim 1 or 2, containing the chlorine atom. 4. The oriented polyester film according to claim 1, wherein the inert particles (B) are at least one of synthetic calcium carbonate particles and heat-resistant organic polymer particles. 5. The oriented polyester film according to claim 1, wherein the area ratio of the inert particles (B) to the circumscribed circle is 60% or more. 6. The oriented polyester film according to claim 1, 4 or 5, wherein the particle size variation of the inert particles (B) is 50% or less. 7. The inert particles (B) have an average particle size of 3
Inert particles (B1) having a particle size of 00 to 650 nm are added to 0.05
To 0.5 wt% and 0.01 to 0.25 wt% of inert particles (B2) having an average particle diameter of 750 to 1300 nm are contained. 8. Inert particles (B2) and inert particles (B
The oriented polyester film according to claim 7, wherein the difference in the average particle size of 1) is 200 to 600 nm. 9. The oriented polyester film according to claim 1, wherein the intrinsic viscosity of the film is 0.5 to 0.6. 10. 0.01% by weight or more of silica particles (a) synthesized by a flame hydrolysis method of silicon tetrachloride and having a specific surface area of 30 to 80 m ² / g and an average particle diameter of 50 to 200 nm. Less than 0.5% by weight, average particle size 30
0.05 to 0.5% by weight of synthetic calcium carbonate particles (b) having a particle diameter of 0 to 650 nm, and an average particle diameter of 750 to 13
Synthetic calcium carbonate particles (c) having a size of 00 nm are 0.0
An oriented polyester film containing 1 to 0.25% by weight. 11. The synthetic calcium carbonate particles (b) and the synthetic calcium carbonate particles (c) both have an area ratio to the circumscribed circle of 60% or more.
The oriented polyester film of 0. 12. The difference between the average particle sizes of the synthetic calcium carbonate particles (b) and the synthetic calcium carbonate particles (c) is 200-.
The oriented polyester film according to claim 10, which has a thickness of 600 nm. 13. The film has an intrinsic viscosity of 0.5 to 0.6.
The oriented polyester film according to claim 10, wherein