JP3282263B2 - Thermoplastic polyester film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester film, and more particularly to a thermoplastic polyester film containing a fluorine compound particle and an inert particle having a specific particle size and having excellent scratch resistance and abrasion resistance. It relates to a biaxially oriented polyester film.

[0002]

2. Description of the Related Art In general, thermoplastic polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate have excellent mechanical properties and are widely used as molded articles such as films. Further, biaxially oriented polyester films made of such polyesters have excellent physical and chemical properties and are widely used. Usually, in order to impart lubricity to the polyester film, a method is employed in which inert particles are contained in the polyester to impart irregularities to the surface of a molded article.

However, the biaxially oriented polyester film is required to increase the processing speed of the film, for example, the printing process in packaging, the coating and calendering of a magnetic layer in magnetic media, or the application of a thermal transfer layer in thermal transfer. However, the disadvantage that the film surface is damaged by the contacting roll has recently become a problem. In many cases, video tapes are recently used for software (produced video works recorded and fixed on a package medium, and duplicated or expanded). In this case, the master tape is used in the process of recording the video works. When dubbing (recording / copying) with, the film surface is scratched by a guide pin or the like or shavings are generated, and the S / N (signal / noise ratio, image quality parameter) is greatly reduced, resulting in poor image quality. Problems are coming up.

[0004] These problems are considered to be problems of particles to be incorporated into polyester, and studies have been made to solve these problems. For example, JP-A-63-221158 and JP-A-63-280763
Japanese Patent Application Laid-Open (JP-A) No. 63-123345 (where the surface of colloidal silica particles is modified with a glycol group), Japanese Patent Application Laid-Open (JP-A) No. 63-313345 (where the surface of colloidal silica particles is modified with a coupling agent), and Japanese Patent Application Laid-Open (JP-A) No. 62-235353 Surface treatment of particles with a phosphorus compound) has been proposed.

[0005] However, even in the case of using such a known method, particles are dropped off when the friction is repeatedly used such as a magnetic tape. For this reason, the use of special particles has recently been proposed. For example, JP-A-62-172031 (silicon particles), JP-A-2-129230 (delta-type aluminum oxide particles), Japanese Patent Application Laid-Open No. 4-282226 (calcium carbonate + other particles) has been proposed but is still insufficient.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and in particular, to include a fluorine compound particle having a specific particle size and an inert particle in a film to improve the surface. It is an object of the present invention to provide a film which is hardly damaged and has excellent scratch resistance and abrasion resistance.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention that the primary particles have an average diameter of not less than 0.002 μm and not more than 0.2 μm.
Aggregate particles of fluorine compound particles (A) less than 0.01
To 2.0 parts by weight, inactive particles (B) having an average primary particle size of 0.2 μm or more and 1.0 μm or less.
0 parts by weight and aromatic polyester (C) 99.98
Thermoplastic polyester fill consisting of up to 93.0 parts by weight
It is achieved by the arm.

The fluorine compound (A) in the present invention means particles having at least one fluorine atom in the structure and substantially insoluble in the aromatic polyester (C). It may be organic.

More specifically, inorganic fluorine compounds such as lithium fluoride, sodium fluoride, potassium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, carbon fluoride, aluminum fluoride, zirconium fluoride, and the like, Examples include, but are not limited to, organic fluorine compounds such as tetrafluoroethane. Among them, magnesium fluoride, calcium fluoride, aluminum fluoride, zirconium fluoride and polytetrafluoroethane are preferable, and calcium fluoride, aluminum fluoride and zirconium fluoride are more preferable. It is essential that at least one of these compounds be used, but two or more of these compounds may be used in combination.

It is essential that the average diameter of the primary particles of the fluorine compound particles (A) is not less than 0.002 μm and less than 0.2 μm, and preferably not less than 0.005 μm and not more than 0.1 μm. The average diameter of the primary particles as used herein refers to an equivalent spherical diameter obtained by observing 100 to 1,000 particles at a magnification of 50,000 to 1,000,000 times with a transmission electron microscope (TEM) and calculating the equivalent sphere diameter so as to have the same volume. It means a diameter corresponding to 50% on a standard basis.

When the primary particles are less than 0.002 μm, the cohesive force of the particles becomes strong, and when formed into secondary aggregated particles of 3 μm or more into a film, the particles easily fall off, which is not preferable. On the other hand, if it is 0.2 μm or more, the surface area of the particles becomes small and the contact area with the polymer becomes small, so that the intended effect cannot be exhibited.

Further, such fluorine compound particles (A)
It is more preferable that a single particle is aggregated to form an aggregate in which a plurality of aggregates are aggregated, since a film is less likely to be oriented in a plane direction and particles are less likely to fall off.

The term "single particles" as used herein means primary particles. At this time, the form is the ratio of the length Dhμm in the direction parallel to the film length direction to the length Dvμm parallel to the direction perpendicular to the film surface, Dv, in the film.
/ Dh preferably has a value of 0.05 to 0.6,
The range of 0.1 to 0.5 is more preferable.

The fact that Dv / Dh is smaller than 1 means that
The agglomeration particles (A) are deformed in the direction of the film surface by the stress at the time of stretching the film, which means that the film is stretched relatively uniformly without generation of voids or the like. If the value of Dv / Dh is less than 0.05, it is difficult to form projections on the film surface, and if it is more than 0.6, the deformation during stretching is small and the uniform stretchability is slightly inferior. Therefore, the value of Dv / Dh is 0.05 or more and 0.6
The following makes it possible to achieve both uniform stretchability and the formation of surface protrusions, and because the aggregated particles oriented in the plane direction have a structure that is strong against external force, more excellent scratch resistance and wear resistance Is expressed.

Such an aggregate preferably has a length Dh of 0.01 to 3.0 μm, more preferably 0.05 to 1.0 μm, in view of scratch resistance and abrasion resistance. . The length Dv is preferably 0.005 to 1.5 μm in terms of scratch resistance and wear resistance,
More preferably, it is 0.01 to 0.2 μm. Dh and Dv of the particles can be controlled by controlling the dispersion state of the fluorine compound particles and the stretching speed, temperature and stretching ratio during film formation.

The thermoplastic polyester 10 of the present invention
The content of the fluorine compound (A) in 0 parts by weight is 0.01 to
2.0 parts by weight. More preferably 0.05 to 1.0
Parts by weight. If the amount is less than 0.01 part by weight, the desired scratch resistance effect cannot be exhibited,
Conversely, if it exceeds 0.2 parts by weight, the abrasion resistance decreases due to the particles falling off.

The inert particles (B) in the present invention mean both inorganic particles and organic particles, and they can be used alone or in combination. Specific examples of the inert inorganic particles include tatatin oxide, silicon oxide,
Inorganic oxides such as zirconium oxide and aluminum oxide; inorganic carbonates such as calcium carbonate and barium carbonate;
Inorganic phosphates such as calcium phosphate and sodium phosphate, inorganic sulfates such as barium sulfate and calcium sulfate,
Examples include inorganic composite oxides such as kaolin and talc, fluorides represented by fluorite, and other general inorganic particles such as potassium titanate and aluminum hydroxide. Among them, titanium oxide, silicon oxide, calcium carbonate,
Calcium phosphate is particularly preferred. Further, two or more of these may be used in combination.

Next, examples of inert organic particles include internal particles resulting from catalyst residues during polyester synthesis, organic low molecular weight compounds such as calcium terephthalate, barium terephthalate and sodium benzoate, carbon black, and polytetrafluorocarbon. Organic polymer compounds such as ethane resin, polystyrene resin, silicone resin, and cross-linked polymer resin are exemplified. Among these, crosslinked polymer resin particles are preferable, and specifically, generally, a monovinyl compound (X) having only one aliphatic unsaturated bond in a molecule and two or more aliphatic compounds in a molecule as a crosslinking agent. Copolymer with compound (Y) having an unsaturated bond, or the latter crosslinking agent (Y)
But are not limited thereto.

Examples of the compound (X) include styrene ■,
α-methylstyrene, fluorostyrene, aromatic monovinyl compounds such as vinylpyridine, acrylonitrile,
Vinyl cyanide compounds such as methacrylonitrile, acrylate monomers such as butyl acrylate, 2-ethylhexyl acrylate, methyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, N, N'-dimethylaminoethyl acrylate, butyl methacrylate, -Ethylhexyl methacrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, N,
Use of methacrylic acid ester monomers such as N'-dimethylaminoethyl methacrylate, monomers such as acrylic acid, methacrylic acid, maleic acid, itaconic acid or amide monomers such as dicarboxylic acids and anhydrides of dicarboxylic acids, acrylamide and methacrylamide Can be. Among them, styrene, α-methylstyrene and p-methylstyrene are preferred.

Examples of the compound (Y) include divinylbenzene compounds, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, Polyhydric acrylates and methacrylates such as 3-butylene glycol dimethacrylate are included. Among them, it is particularly preferable to use divinylbenzene, butyl acrylate, ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate. In addition, these compounds (X) and (Y) may be used as a mixture of two or more kinds.

Preferred examples of the composition of the crosslinked polymer particles include crosslinked polymer particles using divinylbenzene alone, styrene-divinylbenzene copolymer, styrene-acrylonitrile-divinylbenzene copolymer, and styrene-methyl. Methacrylate-divinylbenzene copolymer, butyl acrylate-divinylbenzene copolymer , ethylvinylbenzene-divinylbenzene
A cross-linked polymer using a copolymer is exemplified. Among them, divinylbenzene homopolymer, styrene-divinylbenzene copolymer, butyl acrylate-divinylbenzene copolymer , ethylvinylbenzene-divinylbenzene copolymer
Crosslinked polymer particles using a polymer is particularly preferred in view of heat resistance.

With regard to the heat resistance of the crosslinked polymer particles, particles having a heat decomposition temperature of 380 ° C. or more, preferably 400 ° C., and more preferably 400 ° C.
° C or higher, particularly preferably 410 ° C or higher. In this case, it is preferable because particles are not aggregated at the time of producing the polyester composition, at the time of melt molding, or at the time of collecting and reusing the molded product, and the surface uniformity and wear resistance of the molded product are not alienated. In order to have such heat resistance, it is necessary to highly crosslink with the compound (Y) as a crosslinking agent. The type of the cross-linking agent is not particularly limited, but among them, divinylbenzene is preferable, and 12% by weight or more, preferably 35% by weight or more, more preferably 55% by weight or more, of pure divinylbenzene is required based on all monomers constituting the organic particles. % By weight or more.

[0023] The crosslinked polymer particles have smoothness, surface uniformity,
From the viewpoint of transparency and the like, those having a spherical particle shape and a uniform particle size distribution are preferred. That is, the volume shape factor is 0.35
~ 0.52 is preferred, and more preferably 0.45 or more [where the volume shape factor f is represented by the following formula. f = V / D ³ , where V is the particle volume (μ
m ³ ) and D represent the maximum diameter (μm) of the particle on the projection plane. ].

As the crosslinked polymer particles, those obtained by a known production method can be used. Known production methods include (a) a soap-free polymerization method, that is, a method of polymerizing without using an emulsifier or using an extremely small amount of an emulsifier, and (b) polymer particles into a polymerization system prior to emulsion polymerization. A seed polymerization method in which emulsion polymerization is performed after addition, (c) a core-shell polymerization method in which a part of the monomer component is emulsion-polymerized, and the remaining monomer is polymerized in the polymerization system;
(D) JP-A-54-97582 and JP-A-54-97582
Examples of the polymerization method include a polymerization method using Eugelstatt and the like described in JP-A-126288. Among them, the methods (c) and (d) are preferable. Particles highly crosslinked with divinylbenzene are produced by these methods. Then, a carboxyl group is introduced into the particle surface with methacrylic acid. Then, by setting the inside of the particle production system to the alkali side, a functional group of -COONa is introduced to the particle surface.

The primary particles of the inert particles (B) must have an average diameter of not less than 0.2 μm and not more than 1.0 μm. If it is less than 0.2 μm, the film lacks runnability. Conversely, if it exceeds 1.0 μm, particles will fall off and the abrasion resistance will deteriorate, which is not preferable.

The average particle size of the primary particles of the inert particles (B) as used herein means that the polymer is removed from a film or a polyester composition by a plasma low-temperature incineration method to expose the particles (the processing conditions are as follows. The condition is selected such that the particles are not damaged.), And the particles are observed by a scanning electron microscope (SEM) at 50 to 500 at 2000 to 10000 times, and the particles have the same volume. The sphere diameter is calculated and means a diameter corresponding to 50% on a volume basis.

When the inert particles (B) are organic particles or the like and are damaged by the plasma low-temperature incineration treatment,
3000 to 100 using a transmission electron microscope (TEM)
Observation of 50 to 500 particles at a magnification of 000 times can be performed by the same method.

These inert particles (B) usually have a particle size distribution, and these particles have a particle size distribution of 5 μm.
It is more preferable not to mix the above coarse particles because coarse projections are not generated. In order to obtain particles having such a particle size distribution, it is effective to eliminate agglomerated particles by a dispersion operation such as a sand mill, or to remove agglomerated particles or coarse particles by a classification operation. It is more preferable that the particle sizes are previously adjusted.

The synthesis method when the inert particles (B) are organic particles is as described above. In the case of inorganic particles, especially calcium carbonate, specifically, blowing carbon dioxide gas into an aqueous solution of calcium hydroxide Calcite-type calcium carbonate particles with a uniform particle size are obtained by dispersion and classification to remove some remaining coarse particles, and vaterite-type carbonate by blowing carbon dioxide gas into an alcohol solution of calcium hydroxide. Get calcium particles,
Filtration removes a very small amount of remaining coarse particles.

In the present invention, the fluorine compound particles (A) having a specific particle size and the inert particles (B) having a specific particle size are used in combination, and each is blended in a specific amount, whereby the abrasion resistance of the film is improved. Also, the clutch resistance can be significantly improved.

The aromatic polyester (C) in the present invention
Is produced by a polycondensation reaction using a bifunctional component such as an aromatic dicarboxylic acid or a dialkyl ester thereof and a glycol component as raw materials.

The bifunctional components such as aromatic dicarboxylic acids and dialkyl esters thereof in the present invention include:
Examples include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenylethanedicarboxylic acid, and the like, and dialkyl esters thereof. Examples of the glycol component include an alkylene glycol such as ethylene glycol, tetramethylene glycol, and hexamethylene glycol, and an alicyclic diol such as cyclohexanedimethanol.
In particular, among them, those mainly composed of polyethylene terephthalate and polyethylene-2,6-naphthalate are preferred.

The polyester may be a homopolyester or a copolyester. Examples of the copolymerization component include adipic acid, sebacic acid, phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, Dicarboxylic acid components such as 5-sodium sulfoisophthalic acid, trimellitic acid, polycarboxylic acid components such as pyromellitic acid, and tetramethylene glycol, hexamethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, polyoxyalkylene glycol, Examples of the diol component include p-xylylene glycol, 1,4-cyclohexanedimethanol, and 5-sodium sulforesorcin.

In order to enhance the strength of the biaxially oriented film, the intrinsic viscosity of the aromatic polyester is preferably at least 0.45, more preferably at least 0.50. From the viewpoint of moldability, the intrinsic viscosity is preferably 1.5 or less, more preferably 1.0 or less, and particularly preferably 0.8 or less.

Such an aromatic polyester (C) is
The fluorine compound particles (B) and the inert particles (C) have a preferred dispersion state, and the carboxyl end group concentration is preferably 20 to 100 equivalents per 10 ⁶ g in order to obtain affinity, and 30 to 70 equivalents. More preferably, it is equivalent. The concentration of the carboxy terminal group is controlled by the type and amount of the alkali metal compound, alkaline earth metal compound or Mn compound added during the synthesis of the polyester, or the polymerization temperature and time during the synthesis of the polyester.

The polyester composition and film of the present invention are mainly composed of a composition comprising fluorine compound particles (A), inert particles (B) and aromatic polyester (C). Many kinds of polymers may be blended within a range that does not hinder the addition, and organic additives such as antioxidants, heat stabilizers, lubricants, and ultraviolet absorbers may be added to the extent that they are usually added.

The method and timing of addition of the fluorine compound particles (A) and the inert particles (B) to be mixed with the aromatic polyester (C) are known in the art, for example, powder or glycol. It is possible to adopt a method in which the slurry is used in the form of addition to the polyester reaction system, or a method in which the powder or water or a low-boiling solvent such as lower alcohol is kneaded into the polyester in the form of a slurry.

In particular, in the case of the fluorine compound particles (A) and the inert inorganic particles, it is preferable to add them to the polyester reaction system in the form of a glycol slurry used in the polyester reaction system. Alternatively, a method of kneading the polyester in the form of a slurry using a low boiling point solvent such as water is preferred. In this case, it is more preferable to use a vent-type molding machine for degassing.

The vent type molding machine is a melt molding machine provided with at least one vent hole, and may be, for example, an extrusion molding machine or an injection molding machine. Water and / or boiling point 20
It is preferable that at least one of the vent holes for removing an organic compound at 0 ° C. or lower is kept under reduced pressure. Further, the degree of pressure reduction of the vent hole is preferably maintained at 100 Torr or less, more preferably 50 Torr or less, and 3 Torr or less.
0 Torr or less is more preferable.

When the inert organic particles are, for example, crosslinked polymer particles, the water and / or boiling point of the crosslinked polymer particles is added to the polyester in a vent-type molding machine.
A method obtained by adding an organic compound slurry at 0 ° C. or less, removing water and / or an organic compound having a boiling point of 200 ° C. or less under reduced pressure under heating, and melt-kneading the mixture is more preferable because it is more uniformly and monodispersed.

Examples of the organic compound having a boiling point of 200 ° C. or lower include alcohols such as methanol, ethanol and ethylene glycol, hydrocarbon compounds such as benzene and toluene, and esters, ketones and amines. , Is not particularly limited. Among them, water is preferable from the viewpoint of handling properties, removability and the like. Of course, water and / or the organic compound may be a mixed solvent of two or more kinds, and in that case, a water-rich mixed solvent is preferable.

In the slurry of the crosslinked polymer particles,
Protection of anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, nonionic surfactants such as polyoxyethylene nonyl phenyl ether and polyethylene glycol monostearate, polyvinyl alcohol, carboxymethyl cellulose, etc. which are necessary for the particle manufacturing method It is preferable to include an agent from the viewpoint of particle dispersibility.

Further, the concentration of the water and / or the slurry of the organic compound having a boiling point of 200 ° C. or less of the crosslinked polymer particles is not particularly limited, but the water and / or the boiling point of the polymer are not less than 2%.
2% by weight or more 3
The content is preferably 0% by weight or less. More preferably, the content is 2% by weight or more and 20% by weight or less. This case is preferable because the dispersibility in the polymer is good and the intrinsic viscosity of the polymer does not decrease.

As a method for producing a composition and a film containing both the fluorine compound particles (A) and the inert particles (B), a method of adding both of them to a polyester reaction system may be employed. Alternatively, a method in which master chips separately mixed with a polymer are blended again and melt-kneaded may be employed. The latter method is more preferred from the advantage that the blending amount of the fluorine compound particles (A) and the inert particles (B) in the film can be finely adjusted.

Next, an example of the method for producing a film of the present invention will be described. After sufficiently drying the pellets containing the particles, the pellets are supplied to a known melt extruder, and are heated at 270 to 330 ° C.
And extruded into a sheet from a slit-shaped die, and cooled and solidified on a casting roll to produce an unstretched film. Next, the unstretched film is biaxially stretched and biaxially oriented. As the stretching method, a sequential biaxial stretching method or a simultaneous biaxial stretching method can be used. However, using a sequential biaxial stretching method in which stretching in the longitudinal direction and then in the width direction is performed first, the stretching in the longitudinal direction is divided into three or more stages, and the total longitudinal stretching ratio is 3.5 to 6.5 times. The method is particularly preferred. The stretching temperature in the longitudinal direction varies depending on the type of polyester and cannot be unconditionally determined.
In the second and subsequent stages, it is effective to make the height higher than that. The longitudinal stretching speed is preferably in the range of 5,000 to 50,000% / min. As a stretching method in the width direction, a method using a stenter is generally used. The stretching ratio is 3.0 to
A range of 5.0 times is appropriate. The stretching speed in the width direction is 1
2,000 to 20,000% / min, and the temperature is preferably in the range of 80 to 160 ° C. Next, this stretched film is heat-treated. The heat treatment temperature in this case is 170 to 220 ° C., particularly 1
The temperature is preferably from 80 to 200 ° C. and the time is preferably from 0.2 to 20 seconds.

In the case of a laminated polyester film having two or more layers, two or more melt extruders described above are provided, and a manifold or a merging block having two or more layers (for example, a merging block having a square merging portion) is used. Using a method of forming an unstretched film by laminating a film layer constituting each outermost layer and a film layer constituting an intermediate layer, extruding two or more sheets from a die, and cooling on a casting roll, Biaxial stretching is performed in the same manner.

It is to be noted that a method of installing a static mixer and a gear pump in the polymer channel when producing an unstretched film is effective. Further, it is effective to lower the melting temperature of the extruder for extruding the polymer on the outermost layer laminated portion side by 5 to 10 ° C. than that on the base layer side.

Further, in the biaxially oriented laminated film having the structure of the present invention, the outermost layer on at least one side preferably contains the fluorine compound particles (A) and the inert particles (B). The average particle diameter of the particles (B) is d (n
m), the relationship with the thickness t (nm) of the outermost layer is preferably 0.2d ≦ t ≦ 10d. This improves the electromagnetic conversion characteristics as compared with a single-layer film, and is particularly preferable when used for a magnetic tape. When two or more types of inert particles were used, the average value (equivalent diameter of 50%) of the whole was defined as d.

In the laminated film of the present invention, at least one of the layers constituting the laminated film must be biaxially oriented. It is particularly preferable that all the layers in the two or more layered structure are biaxially oriented. If all the layers are not oriented or uniaxially oriented, the properties of the present invention cannot be satisfied.

[0050]

Next, the present invention will be specifically described with reference to Examples and Comparative Examples. (1) Intrinsic viscosity of polymer 0.1 g /
It was dissolved at a cc concentration and measured at 25 ° C.

(2) Concentration of carboxyl terminal group of polymer The procedure was based on the method of Maurice. The polymer 2g was dissolved in a mixed solvent 50cc of o- cresol / chloroform (weight ratio 7/3), titration, the carboxyl end group concentration was determined by N / 20-NaOH methanol solution, the value of eq / polyester 10 ⁶ g Indicated.

(3) Average diameter of primary particles of fluorine compound particles The particles themselves, or a polymer and a film containing the particles, obtained by cutting an ultrathin section with a thickness of 0.2 μm, using a transmission electron microscope to a magnification of 50,000 times or more. 100 to 1000 pieces were observed at a magnification of 1,000,000 times, the equivalent sphere diameter was calculated to have the same volume, the cumulative particle size distribution on a volume basis was obtained, and the particle diameter at 50% was defined as the average diameter (μm).

(4) Particle diameter D of the fluorine compound in the film
h, Evaluation of Dv From the film, a 0.2 μm-thick ultrathin section having a plane formed by the film length direction and a direction perpendicular to the film surface was cut out, observed with a transmission electron microscope, and examined for fluorine compound particles. The length Dh (μ
m) and the length Dv (μ) perpendicular to the film surface.
m) were measured, and an average was determined.

(5) Average diameter of primary particles of inert particles The polymer is removed from the polymer or film containing the particles by a plasma low-temperature incineration method to expose the particles. Processing conditions are selected such that the polymer is ashed but the particles are not damaged. Next, the particles are observed using a scanning electron microscope (SEM) at 2,000 to 10,000 times at 50 to 500 particles, the equivalent sphere diameter so as to have the same volume is calculated, and the volume-based cumulative particle size distribution is calculated. The particle diameter at 50% was taken as the average diameter (μm). If the particles are significantly damaged by the plasma low-temperature incineration treatment method using organic particles or the like, use a transmission electron microscope (TEM) to observe 50 to 500 particles at 3,000 to 100,000 times and observe the same as above. The average diameter was measured by the method described above.

(6) Evaluation of Center Line Average Roughness of Film Surface According to JIS B-0601, using a Surfcom surface roughness meter, needle diameter: 2 μm, load: 70 mg, measurement reference length;
The center line average roughness (Ra) was measured under the conditions of 0.25 mm, cutoff; 0.08 mm.

(7) Evaluation of abrasion resistance of film The tape coated with the magnetic layer was heated at a temperature of 70 using a small test calender (steel roll, nylon roll, 5-stage type, nylon roll in contact with the base film surface).
Calendering is performed at 200 ° C. and a linear pressure of 200 kg / cm. After the above treatment is continued for a total of 10,000 m, the white powder adhered to the nylon roll generated by this treatment is observed, and the following ranking is performed. And first grade and 2
Class passed. Grade 1: Almost no white powder adheres. Second grade: White powder slightly adheres, but does not lead to trouble in processing process and product performance. 3rd grade: Many white powders adhered, causing troubles in the processing process and product performance, making it unusable.

(8) Scratch resistance of film A film obtained by slitting a film into a tape having a width of 1/2 inch is run on guide pins (surface roughness: 100 nm in Ra) using a tape running tester. (Running speed; 500 m / min, number of runs; 10 passes, winding angle;
60 °, running tension; 60 g). At this time, the scratches in the film were observed under a microscope and ranked as follows.
Grade or higher was passed. First grade: 0 to 3 scratches with a width of 3 μm or more per tape width Second grade: 4 to 6 scratches with a width of 3 μm or more per tape width Third grade: 7 to 9 scratches with a width of 3 μm or more per tape width : 10 or more scratches with a width of 3 μm or more per tape width

[0058] (9) the slipperiness mu _k film of the film was slit to 1/2 inch, tape running tester TBT-300 type [Corporation Yokohama System Laboratory Ltd.]
, And running in a 20 ° C., 60% RH atmosphere, and the initial μ _k was determined by the following equation. The guide diameter is 6mm
φ, and the guide material is SUS27 (surface roughness 0.2
S), the winding angle is 180 °, and the running speed is 3.3 cm /
Seconds. μ _k = 0.773 log (T ₁ / T ₂ ) T ₁ ; outgoing tension T ₂ ; ingoing tension If the above μ _k is 0.35 or less, the sliding property is good. Here, slipperiness when mu _k is that the larger the film during processing or product than 0.35 is extremely poor.

(10) Electromagnetic Conversion Characteristics of Tape A magnetic paint having the following composition is applied to a film by a gravure roll, magnetically oriented, and dried. In addition, a small test calendar device (steel roll / nylon roll,
5 steps), temperature: 70 ° C., linear pressure: 200 kg / c
After calendering at m, curing is performed at 70 ° C. for 48 hours. The raw tape was slit into 1/2 inch to prepare a pancake. Length 2 from this pancake
A length of 50 m was assembled into a VTR cassette to form a VTR cassette tape. (Composition of magnetic paint) Co-containing iron oxide: 100 parts by weight Vinyl chloride / vinyl acetate copolymer; 10 parts by weight Polyurethane elastomer: 10 parts by weight Polyisocyanate: 5 parts by weight Lecithin: 1 part by weight Methyl ethyl ketone 75 parts by weight; methyl isobutyl ketone; 75 parts by weight; toluene; 75 parts by weight; carbon black; 2 parts by weight; lauric acid; 1.5 parts by weight. The% chroma signal was recorded, and the chroma S / N was measured from the reproduced signal using a color video noise measuring instrument.

[0060] 10 parts by weight calcium fluoride particles having an average diameter 0.025μm Example 1 primary particles (25 nm), mixed with ethylene glycol 90 parts by weight, followed by stirring treatment at room temperature for 1 hour under a dissolver chromatography, sand grinder Disperse calcium fluoride /
An ethylene glycol slurry (a) was obtained.

On the other hand, a transesterification reaction was carried out by adding 0.06 parts by weight of magnesium acetate as a catalyst to 100 parts by weight of dimethyl terephthalate and 64 parts by weight of eletin glycol, and the reaction product was first adjusted at 230 ° C. Twenty parts by weight of the slurry (a) was added, and after 10 minutes, 0.03 part by weight of antimony oxide as a catalyst and 0.03 part by weight of trimethyl phosphate as a heat-resistant stabilizer were added, and a polycondensation reaction was carried out. Thus, a polyethylene terephthalate composition (I) having a carboxyl end group concentration of 38 equivalents / 10 ⁶ g was obtained.

10 parts by weight of calcite-type calcium carbonate having an average primary particle diameter of 0.53 μm, 2 parts by weight of a poly (acrylic acid / ethyl acrylate) copolymer (composition weight ratio 8: 2), 88 parts by weight of ethylene glycol Mixed at room temperature for 1
After a stirring treatment with a time dissolver, a dispersion treatment was performed with a sand grinder to obtain a calcite-type calcium carbonate / ethylene glycol slurry (b) whose surface was treated.

On the other hand, a transesterification reaction was carried out by adding 0.06 parts by weight of magnesium acetate as a catalyst to 100 parts by weight of dimethyl terephthalate and 64 parts by weight of ethylene glycol, and then the slurry prepared at 230 ° C. was added to the reaction product. (B) 20 parts by weight were added, and after 10 minutes, 0.03 parts by weight of antimony oxide as a catalyst and 0.03 parts by weight of trimethyl phosphate as a heat-resistant stabilizer were added, and a polycondensation reaction was carried out to give an intrinsic viscosity of 0.621. A polyethylene terephthalate composition (II) having a carboxyl terminal group concentration of 42 equivalents / 10 ⁶ g was obtained.

Next, polyethylene terephthalate (III) containing no particles (intrinsic viscosity 0.618, carboxyl end group concentration 40 equivalents / 10 ⁶ g) was prepared, and the above-mentioned (I), (II) and (III) were used. Is 20 / by weight ratio
It was blended to be 15/65.

The polymer was dried under reduced pressure (3 Torr) at 180 ° C. for 3 hours. Thereafter, the polymer was supplied to an extruder, melted at 290 ° C., wound around a casting drum having a surface temperature of 30 ° C., and cooled and solidified to produce an unstretched film.

This unstretched film was stretched 4.5 times in the longitudinal direction at a temperature of 80 ° C. This stretching was performed in four stages with a difference in peripheral speed between two sets of rolls. This uniaxially stretched film is stretched at a stretching speed of 2000% / min.
Stretched 4.0 times in the width direction at 200 ° C, and
Heat treatment was performed for 2 seconds to obtain a biaxially oriented polyester film having a thickness of 15 μm and Ra = 0.022 μm. The film had an intrinsic viscosity of 0.597 and a carboxyl end group concentration of 45 equivalents / 10 ⁶ g. Observation of the calcium fluoride particles in this film with a transmission electron microscope revealed that Dh was 0.1.
2 μm, Dv was 0.04 μm, and Dv / Dh was 0.2. When this film was evaluated,
_k = 0.21, abrasion resistance class 1 and scratch resistance class 1 were very excellent.

Examples 2 to 6 Types of fluorine compound particles, primary diameter, Dh in film,
The biaxially oriented polyester film was obtained in the same manner as in Example 1 except that the type and primary diameter of Dv and the inert particles were changed.
The evaluation results of these films are shown in Table 1. The films were excellent in abrasion resistance and scratch resistance.

The polymer containing inert organic particles was prepared according to the following method. An undried polyethylene terephthalate chip not containing particles having an intrinsic viscosity of 0.621 containing water of 0.4% by weight and a carboxyl end group concentration of 42 equivalents / 10 ⁶ g was melted using a vent type twin screw extruder. And the average particle size is 0.43 so that the final polymer content is 2.0% by weight.
A water slurry of polydivinylbenzene (divinylbenzene / ethylvinylbenzene = 80/20: weight ratio) copolymer particles having a sodium salt of a carboxyl group as a functional group in μm was added. The ventro was maintained at a vacuum of 10 Torr, and was melt-extruded at a resin temperature of 280 ° C. to obtain a polyethylene terephthalate composition (IV) containing polydivinylbenzene particles.

The resulting polyethylene terephthalate composition (IV) had an intrinsic viscosity of 0.616 and a carboxyl end group concentration of 48 equivalents / 10 ⁶ g.

Example 7 The polyethylene terephthalate composition (I) described above,
(II) and (III) are mixed at a weight ratio of 15/30/55, and dried under reduced pressure at 180 ° C. for 3 hours (3To
rr) and fed to the vented twin-screw kneading extruder 1
C. (Polymer X).

Further, only the polyethylene terephthalate composition (III) was dried at 180 ° C. for 3 hours under reduced pressure (3To
rr), and supplied by another twin-screw kneading extruder 2 to
Melted at 90 ° C. (Polymer Y).

After high-precision filtration of each of the two polymers, a three-layer merging block having a rectangular laminated portion laminates polymer Y on the base layer and polymer X on the double-sided surface laminated portion. After extruding into a sheet form from the die of the mold, the surface temperature was adjusted to 3 using an electrostatic application casting method.
Wrap around a 0 ° C casting drum to cool and solidify,
An unstretched film about 160 μm thick was made. Draft ratio at this time (ratio of die slit width to film thickness)
Was 6.5.

The unstretched film was divided into three stages in the longitudinal direction, and 1.2 times at 123 ° C., 1.45 times at 126 ° C.,
Each was stretched 2.3 times at 14 ° C. This uniaxial film was divided into two stages in the width direction using a stenter, stretched 3.7 times at 111 ° C., 1.2 times at 113 ° C., and stretched 200 times at a constant length.
C. for 5 seconds, thickness 14 μm, Ra = 0.02
A 1 μm film was obtained. The intrinsic viscosity of the film is 0.6
01, the carboxyl end group concentration was 48 equivalents / 10 ⁶ g.

The outermost layer thickness t =
The relation with the average diameter d of calcite-type calcium carbonate particles at 1.0 μm, d = 0.53 μm, was t = 1.89d. When the calcium fluoride particles in the laminated portion were observed with a transmission electron microscope, Dh was 0.2 μm, Dv was 0.03 μm, and Dv / Dh was 0.15.

Table 2 shows the film characteristics.
Similarly to the above, both abrasion resistance and scratch resistance were good. In addition, when the electromagnetic conversion characteristics were also measured, the film was +1.8 dB based on Example 1, which was a very good film for use as a magnetic tape.

Examples 8 to 10 Kinds of fluorine compound particles, primary diameter, Dh in film,
A biaxially oriented laminated polyester film was obtained in the same manner as in Example 7, except that the type of Dv and inert particles, the primary diameter, and the thickness of the laminate were changed. The evaluation results of these films are shown in Table 2, and they were excellent in abrasion resistance and scratch resistance. In addition, the electromagnetic conversion characteristics for magnetic tape applications were also good.

Example 11 100 parts by weight of dimethyl naphthalene-2,6-dicarboxylate, 52 parts by weight of ethylene glycol and 0.06 of magnesium acetate tetrahydrate were placed in a transesterification reactor equipped with a stirrer, a rectification column and a condenser. After supplying the parts, 180-240
The temperature was gradually raised to 0 ° C., and the transesterification reaction was carried out while simultaneously distilling off the produced methanol continuously out of the reaction system. To the reaction product thus obtained, 20 parts by weight of the slurry (a) prepared above was added, and 10 minutes later, 0.03 parts by weight of antimony oxide as a catalyst and 0.03 parts by weight of trimethyl phosphate as a heat stabilizer were added. Subsequently, the temperature was raised to 290 ° C. while continuously distilling ethylene glycol, and at the same time, the polycondensation reaction was carried out by reducing the pressure to 0.2 mmHg. The intrinsic viscosity was 0.64, and the concentration of carboxyl end groups was 42 equivalents / 10 ⁶ g. To obtain a polyethylene-2,6-naphthalate composition (V).

Next, a polyethylene-2,6-naphthalate composition (VI) was obtained in the same manner as in the above except that the slurry (b) was used instead of the slurry (a). The intrinsic viscosity was 0.64, and the carboxyl end group concentration was 45 equivalents / 10 ⁶ g. Next, polyethylene-2,6-naphthalate (VII) containing no particles (intrinsic viscosity 0.63, carboxyl terminal group concentration 42 equivalent / 10
⁶ g) was prepared, the above-described (V), (VI), (VI
It blended so that I) might be 20/15/65 by weight ratio.

This polymer was preliminarily dried at 130 ° C. for 3 hours under reduced pressure (3 Torr), and then dried at 180 ° C. for 3 hours under reduced pressure (3 Torr). Thereafter, the polymer was extruded from an extruder equipped with a T-die and heated to 300 ° C., and was cooled and solidified in a casting drum at 35 ° C. to obtain an amorphous sheet. After heating the amorphous sheet to 130 ° C. and stretching it 5 times in the machine direction and then 4 times in the transverse direction,
Heat treatment at 210 ° C., thickness 13 μm, Ra = 0.
A 020 μm biaxially stretched polyethylene-2,6-naphthalate film was obtained. The intrinsic viscosity of this film is 0.6
1. The carboxyl end group concentration was 46 equivalents / 10 ⁶ g.

When the calcium fluoride particles in the film were observed with a transmission electron microscope, Dh was 0.15 μm.
m and Dv were 0.03 μm, and Dv / Dh was 0.2. Also, when this film was evaluated, the running property μ _k
= 0.20, abrasion resistance class 1 and scratch resistance class 1 were very good. Also, when the electromagnetic conversion characteristics were measured, it was +0.5 dB based on Example 1 and was a very good film for use as a magnetic tape.

Example 12 Polyethylene terephthalate compositions (I) and (II)
Using polyethylene-2,6-naphthalate compositions (V), (VI) and (VII) instead of (III),
Preliminary drying under reduced pressure (3 Torr) at 3 ° C. for 3 hours, drying under reduced pressure (3 Torr) at 180 ° C. for 3 hours, supply to the twin-screw kneading extruder 1, and melting at 300 ° C., using the same method as in Example 7. Thus, a laminated unstretched film having a thickness of 260 μm was obtained.

Next, the unstretched film was stretched 5 times in the machine direction at 130 ° C. and then 4 times in the transverse direction,
And heat treatment, thickness 13 μm, Ra = 0.19 μm
m of biaxially stretched polyethylene-2,6-naphthalate film. The outermost layer thickness t of this film is 1.
At 0 μm, the average diameter d of the calcite-type calcium carbonate particles is d =
The relationship with 0.53 μm was t = 1.89d. When the calcium fluoride particles in the laminated portion were observed with a transmission electron microscope, Dh was 0.18 μm and Dv was 0.1 μm.
03 μm, Dv / Dh = 0.17.

When the film properties were evaluated, the running property was μ _k = 0.19, the abrasion resistance was first class, and the scratch resistance was first class, which was very good. Further, when the electromagnetic conversion characteristics were also measured, the value was +2.0 with respect to Example 1.
It was a very good film for dB and magnetic tape applications.

Comparative Examples 1 to 6 The same method as in Example 1 was used except that the type, primary diameter and amount of fluorine compound particles, and the types, primary diameters and amounts of Dh and Dv and inert particles in the film were changed. To obtain a biaxially stretched polyester film. Table 3 shows the evaluation results of these films.
However, the film performance was insufficient. In particular, when only one of the particles was added, as in Comparative Examples 5 and 6, the abrasion resistance class 3 and the scratch resistance 4
Class and bad.

Comparative Examples 7 to 10 The same method as in Example 7 was carried out except that the types, primary diameters and amounts of fluorine compound particles, the types, primary diameters and amounts of Dh and Dv and inert particles in the film were changed. To obtain a biaxially stretched laminated polyester film. The evaluation results of these films are shown in Table 4, but the film performance was insufficient. In particular, when only one of the particles was added as in Comparative Examples 9 and 10, the abrasion resistance was 3 grade and the scratch resistance was 4 grade.

[0086]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[0087]

The thermoplastic polyester film of the present invention contains a specific particle size and amount of fluorine compound particles and a specific particle size and amount of inert particles, and is excellent in scratch resistance and abrasion resistance. Yes, it can cope with an increase in film processing speed in each application. Although the use of the film of the present invention is not particularly limited, it is particularly useful as a base film for a magnetic recording medium in which scratches on the film surface in the processing step are particularly problematic in the processing step and product performance.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 67/00-67/03

Claims (2)

(57) [Claims] An agglomerate of fluorine compound particles (A) having an average diameter of primary particles of not less than 0.002 μm and less than 0.2 μm (A) 0.01 to 2.0 parts by weight, and an average diameter of primary particles of 0.2 μm Inert particles (B) having a size of at least 1.0 μm
A thermoplastic polyester film comprising 0.01 to 5.0 parts by weight and 99.98 to 93.0 parts by weight of an aromatic polyester (C). 2. A thermoplastic polyester off of claim 1, wherein
A laminated polyester film comprising at least one film layer .