JPH08113700A - Polyester composition and film prepared therefrom - Google Patents

Abstract

PURPOSE: To obtain a polyester composition which is excellent in surface smoothness, slipperiness and wear resistance when formed into films by using specific particles and setting the composition and amount of a metallic compound contained in specific ranges. CONSTITUTION: This composition comprises a polyester containing 0.005-2.0wt.% of an organic polymer particles having an average particle size of 0.01-0.6μm and a particle size ratio (length/breadth) of 1.0-1.5 and at least one of an Mn compound and an Mg compound, a Ge compound and a P compound in amounts that satisfy the conditions of formulae I-III. Here, M, Ge and P represent the mol% of each atom of Mg or Mn, Ge and P in the Mg or Mn compound, Ge compound and P compound, respectively, based on a lower alkyl ester of a dicarboxylic acid. The composition is excellent in surface smoothness, slipperiness and wear resistance when formed into films and may suitably be used for magnetic recording media applications.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to polyester compositions. More specifically, the present invention relates to a polyester composition which contains specific particles and is excellent in smoothness, slipperiness and abrasion resistance when formed into a film, and a film comprising the same.

[0002]

2. Description of the Related Art Due to its excellent properties, polyester film is widely used in many applications such as magnetic tape, electrical insulation, photography, metallization and packaging. . Especially, polyethylene terephthalate film and polyethylene-2,6-naphthalate film have flatness,
It has excellent mechanical strength, chemical properties, dimensional stability, etc.,
It is preferably used as a base film for magnetic recording media.

On the other hand, with the recent development of magnetic recording media, the characteristics required for the base film have become increasingly severe.

For example, in order to increase the density of a video tape, the flatness of the surface of the base film is required. However, when the surface becomes flat, friction and wear on the surface increase, which causes many problems such as scratches on the film surface and generation of shavings. Here, if the base film has low abrasion resistance, a large amount of film abrasion powder is generated during the magnetic tape manufacturing process, resulting in coating omission during the magnetic layer application process, resulting in magnetic recording omission (dropout). . In addition, when using a magnetic tape, in most cases, it travels while contacting the recording / playback area, so the shavings generated during contact adhere to the magnetic material, resulting in dropout of magnetic recording during recording / playback. Cause

That is, the base film is required to have slipperiness and abrasion resistance both during the magnetic tape manufacturing process and when used as a magnetic tape.

Particles are added to the film to impart slipperiness and projections are formed on the surface to reduce friction. On the other hand, particles that form projections that are less likely to come off are required due to the demand for improved wear resistance. Has been.

As such particles, particles made of an organic polymer have been proposed in recent years as opposed to conventional inorganic particles represented by silica and the like.

Since the organic polymer particles have a high affinity with polyester and are more elastic than the inorganic particles, the occurrence of voids around the particles during film forming is small and the abrasion resistance is excellent. For example, in JP-A-55-99948, it is proposed to use particles made of a methylmethacrylate-divinylbenzene polymer or the like. In addition, JP-A-2-
194049 proposes to use organic particles coated with a cross-linked polymer having ethylene glycol units.

However, with the recent technological progress in the magnetic recording field and the like, particles excellent in slipperiness and abrasion resistance are required.

In addition to slipperiness and abrasion resistance, the base film has higher elastic modulus for thinning the base film and improvement of smoothness in addition to higher density of the magnetic recording medium. It is strongly requested. The smoothness of the film surface is affected not only by the particle size distribution of the particles in the film but also by various catalysts and stabilizers used in the polymerization of polyester. Japanese Unexamined Patent Publication (Kokai) No. 2-103116 discloses catalyst conditions for improving the uniformity of film thickness, but such a method achieves both productivity and thickness uniformity, but the surface smoothness is insufficient. there were. Further, Japanese Patent Laid-Open No. 61-78829 discloses a method for producing a polyester using a germanium compound. In such a method, insoluble fine particles due to a catalyst are reduced and transparency is improved, and the film is also improved. Although it contributes to the smoothness of the surface, it was insufficient when slipperiness and runnability were required at the same time as in the field of magnetic recording.

[0011]

[Problems to be Solved by the Invention]
By thoroughly studying the problems, it was found that the above-mentioned problems can be solved by using specific particles and setting the composition and amount of the metal compound contained in a specific range. An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a polyester composition excellent in slipperiness, smoothness and abrasion resistance when formed into a film or the like.

[0012]

The object of the present invention is to provide an organic high particle having an average particle size of 0.01 μm to 0.6 μm and a particle size ratio (major axis / minor axis) of 1.0 to 1.5. 0.
A polyester containing 005 to 2.0% by weight,
A polyester composition containing at least one of a magnesium compound or a manganese compound, a germanium compound and a phosphorus compound so as to satisfy the conditions of the formulas (1) to (3), respectively.

0.01 ≦ M ≦ 0.15 (1) 0.005 ≦ Ge ≦ 0.15 (2) 0.5 ≦ M / P ≦ 5 (3) (where M, Ge, and P represents a mol% relative to a lower alkyl ester of a dicarboxylic acid as each atom of magnesium or manganese, germanium, or phosphorus in a magnesium compound or a manganese compound, a germanium compound, or a phosphorus compound.).

The polyester in the present invention may be any one as long as it can form a film, for example, polyethylene terephthalate, polytetramethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalate, polyethylene-1. , 2-bis (2-chlorophenoxy) ethane-4,4′-dicarboxylate and the like,
Polyethylene terephthalate or polyethylene-
2,6-naphthalate is preferable, and polyethylene-2,6-naphthalate is particularly preferable when high elastic modulus is required.

These polyesters include dicarboxylic acids such as adipic acid, isophthalic acid, sebacic acid, phthalic acid, 4,4'-diphenyldicarboxylic acid and their ester-forming derivatives, polyethylene glycol, diethylene glycol and hexa as copolymerization components. Dioxy compounds such as methylene glycol, neopentyl glycol and polypropylene glycol, oxycarboxylic acids such as p- (β-oxyethoxy) benzoic acid and ester-forming derivatives thereof may be copolymerized.

The organic polymer particles in the present invention are not particularly limited, and any particles may be used as long as at least a part thereof is insoluble in polyester. As materials for such particles, various materials such as polyimide, polyamideimide, polymethylmethacrylate, formaldehyde resin, phenol resin, polystyrene, and polysilsesquioxane so-called silicone resin can be used, but they have high heat resistance. In addition, vinyl-based crosslinked polymer particles are particularly preferred because particles having a uniform particle size distribution can be easily obtained.

The vinyl-based crosslinked polymer particles are monovinyl compounds (A) having only one aliphatic unsaturated bond in the molecule.
And a compound (B) having two or more aliphatic unsaturated bonds in the molecule as a crosslinking component.

Examples of the compound (A) in the above copolymer include aromatic monovinyl compounds such as styrene, α-methylstyrene, fluorostyrene, vinylpyrine and ethylvinylbenzene, and vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. Acrylic ester monomers such as methyl acrylate, ethyl acrylate, propyl acrylate, hexadecyl acrylate, octyl acrylate, dodecyl acrylate, hexadecyl acrylate, glycidyl acrylate, N, N'-dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate , Isopropyl methacrylate, butyl methacrylate, sec-butyl methacrylate, acrylic methacrylate, phenyl Methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2-
Methacrylic ester monomers such as hydroxyethyl methacrylate, glycyl methacrylate, N, N'-dimethylaminoethyl methacrylate, etc., acid anhydrides of mono- or dicarboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc. Amide-based monomers such as acrylamide, acrylamide and methacrylamide can be used.

As the compound (A), styrene, ethylvinylbenzene, methylmethacrylate, etc. are preferably used.

Examples of the compound (B) are divinylbenzene compounds, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,
Alternatively, ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate,
Included are polyvalent acrylates and methacrylates such as 1,3-butylene glycol dimethacrylate.

Among the compounds (B), it is particularly preferable to use divinylbenzene, ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate.

Preferred examples of the composition of the vinyl-based crosslinked polymer particles include divinylbenzene polymer, ethylvinylbenzene-divinylbenzene copolymer, styrene-divinylbenzene copolymer, ethylene glycol dimethacrylate polymer, styrene- Examples thereof include ethylene glycol dimethacrylate copolymer and methyl methacrylate-divinylbenzene copolymer. However, it is not limited to these examples, and for example, styrene-
It may be a copolymer system of three or more components such as an ethyl vinyl benzene-divinyl benzene copolymer and a styrene-ethylene glycol dimethacrylate-methyl methacrylate copolymer.

Such vinyl polymer particles can be produced, for example, by mixing the compounds (A) and (B) and subjecting them to emulsion polymerization. (A) Soap-free polymerization method, that is, a method in which an emulsifier is not used or an extremely small amount of emulsifier is used for polymerization. (B) A seed polymerization method in which polymer particles are added to the polymerization system prior to emulsion polymerization and emulsion polymerization is performed. (C) A core-shell polymerization method in which a part of the monomer components is emulsion-polymerized and the remaining monomers are polymerized in the polymerization system. (D) A polymerization method using Eugelstat or the like disclosed in JP-A-54-97582. (E) A polymerization method in which a swelling aid is not used in the method (d).

The organic polymer particles of the present invention have a thermal decomposition temperature measured by a thermobalance (10% reduction temperature, in a nitrogen stream, at a heating rate of 1).
Particles having a heat resistance of 0 ° C / min) of 350 ° C or higher are agglomerated during production of the polyester composition, melt molding, or recovery / reuse of the molded product, and the film surface uniformity and abrasion resistance are excluded. It is preferable in that it does not
More preferably 360 ° C. or higher, and particularly preferably 370
℃ or above.

The organic polymer particles in the present invention have a degree of cross-linking defined by the formula (1) of 10% by weight or more based on the total organic components constituting the particles, and the dispersibility of the particles when formed into a polyester film. Is preferable, and more preferably 30% by weight or more, and particularly preferably 50% by weight or more. Crosslinking degree = (weight of crosslinking component in raw material monomer) / (total weight of raw material monomer) × 100 (%) (4)

The average particle size of the organic polymer particles in the present invention is 0.01 to 0.6 μm. It is more preferably 0.02 to 0.5 μm, and particularly preferably 0.02 to less than 0.3 μm. The average particle size of the organic polymer particles is 0.01 μm
If it is less than 0.6 μm, the slipperiness of the film becomes insufficient, and if it exceeds 0.6 μm, abrasion resistance or surface smoothness becomes insufficient.

The organic polymer particles in the present invention have a particle size ratio R (major axis / minor axis) of 1.0 to 1.5 in the film from the viewpoint of slipperiness when formed into a film. is necessary. The particle size ratio R is preferably 1.0 to 1.3, more preferably 1.0 to 1.1.

If the organic polymer particles in the present invention have a uniform particle size distribution, protrusions are formed more uniformly on the film surface and less coarse particles are mixed in, so that the slipperiness and abrasion resistance are better. Become. Specifically, the relative standard deviation of the particle size distribution of the organic polymer particles is preferably 0.5 or less, more preferably 0.3 or less, and particularly preferably 0.
It is preferably 15 or less.

The content of the organic polymer particles in the present invention is 0.005 to 2.0% by weight, preferably 0.05.
˜2.0 wt%, especially 0.1 to 0.5 wt%.
If the content is less than 0.005% by weight, the slipperiness of the film is not sufficient, and if it exceeds 2.0% by weight, the abrasion resistance becomes insufficient, which is not preferable.

The metal compound contained in the polyester of the present invention is mainly derived from the polyester polymerization catalyst and additives such as antistatic agents, but at least one of magnesium compound and manganese compound derived from the transesterification reaction catalyst. And a phosphorus compound must be contained so as to satisfy the following formulas (1) and (3). If the compound is not contained or if it is in the range other than the formulas (1) and (3), foreign matter is generated in the polyester, resulting in insufficient smoothness when formed into a film or the like, film-forming property, so-called electrostatic applicability. Is insufficient. In addition, it is necessary to contain a germanium compound so as to satisfy the formula (2). If the compound is not contained or is in a range other than the formula (2), the smoothness becomes insufficient when the film is made.

In the present invention, the existing state of the above compound in the polyester is not particularly limited. Therefore, in order to contain the compound in the polyester, it may be added as an esterification or transesterification reaction catalyst, a polycondensation catalyst, an anti-adhesion agent, or the like. Examples of magnesium compounds and manganese compounds include magnesium or manganese hydrides, alcoholates, chlorides, acetates, carbonates, carboxylates, sulfates and the like. Examples of germanium compounds include germanium oxides, organic acid salts, and alkyl or aryl compounds. Specific examples thereof include germanium oxide, germanium tetraacetate, germanium oxalate, germanium tartrate, and tetraphenyl germanium. The phosphorus compound is also not particularly limited, and examples thereof include phosphoric acid, phosphorous acid, phosphonic acid and derivatives thereof. Specifically, phosphoric acid, phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tributyl ester, phosphoric acid triphenyl ester, phosphoric acid monomethyl ester, phosphoric acid dimethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, Phosphorous acid, trimethyl phosphite, triethyl phosphite, tributyl phosphite, methylphosphonic acid, methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester,
Examples thereof include phenylphosphonic acid diphenyl ester.

The polyester composition of the present invention can be produced at any time during ordinary polyester production, for example, during the transesterification reaction or the polymerization reaction in the case of the transesterification method,
Alternatively, in the case of the direct polymerization method, at a desired time, a method of adding organic polymer particles in the form of powder or glycol slurry or a method of kneading into polyester in the form of powder or slurry using a low boiling point solvent is used. It is possible. At this time, the catalyst and the additive may be added and contained so as to satisfy the formulas (1) to (3). In particular, a method of kneading the particles into the polyester in the form of water and / or an organic compound slurry having a boiling point of 200 ° C. or lower is preferable because the dispersibility of the particles is good. In this case, it is more preferable to use a vent type extruder for degassing.

At this time, a known surfactant such as sodium dodecylbenzene sulfonate, sodium lauryl sulfate, sodium dialkylsulfosuccinate, or a formalin condensate salt of naphthalene sulfonic acid is added to the organic polymer particle slurry. Agents, nonionic surfactants such as polyoxynonylphenol ether, polyethylene glycol monostearate, sorbitan monostearate, or water-soluble polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol water-soluble synthetic polymers, gelatin, starch, etc. It is preferable to add a natural polymer, a water-soluble semi-synthetic polymer such as carboxymethyl cellulose, or the like, since the particle dispersibility in the slurry and the particle dispersibility in a polyester composition are good.

In the polyester composition of the present invention, other than the organic polymer particles, other particles such as silicon oxide, titanium oxide, aluminum oxide, calcium carbonate and zirconium oxide can be used as long as they do not impair the object of the present invention. Particles or particles such as internal particles that precipitate in a polyester polymerization reaction system containing at least one of an alkali metal and an alkaline earth metal and phosphorus as a part of its constituent components, that is, particles such as internal particles may be contained.

The film composed of the polyester composition of the present invention can be applied to either a single layer film or a laminated film, but from the viewpoint of surface flatness, at least one film composed of the polyester composition of the present invention is laminated. Film is preferred. Further, it is more preferable that the laminated film has a structure of three or more layers, and particularly, at least one of the laminated films in which the polyester film of the present invention has a three-layer structure.
It is preferably the two outermost layers.

Further, from the viewpoint of abrasion resistance, it is particularly preferable that the film composed of the polyester composition of the present invention is arranged in the outermost layer, and the film layer thickness t and the average particle diameter D of the organic polymer particles are The relationship is 0.2D ≦ t ≦ 10D,
Preferably 0.5D ≦ t ≦ 5D, particularly preferably 0.5D
In the case of D ≦ t ≦ 3D, the outermost layer has a thickness of 0.
The thickness is preferably 005 to 1 μm, more preferably 0.01 to 0.5 μm, and particularly preferably 0.02 to 0.3 μm.

This polyester film has a number of projections of at least 2 × 10 ³ to at least on one side from the viewpoint of abrasion resistance.
It is preferably 5 × 10 ⁵ pieces / mm ² . 3 × 10 ³ to 4 × 10 ⁵ pieces / mm ² , preferably 5 × 10 3
^It is preferably ^{3 to} 3 × 10 ⁵ pieces / mm 2.

Next, a method for producing a film made of the polyester composition of the present invention will be described by taking a case of a laminated film as an example.

The organic polymer particles in the present invention and, if necessary, the pellets containing a predetermined amount of other particles are dried and then fed to a known melt extruder, extruded into a sheet form from a slit die, and a casting roll. The above film is cooled and solidified to prepare an unstretched film. In the case of a laminated film, two or more extruders, two or more layers of manifolds or merging blocks are used to laminate polyester in a molten state. In this case, a method of installing a static mixer or a gas pump in the flow path containing the particles may be used.

Next, this unstretched film is biaxially stretched to be biaxially oriented. As a 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 is first performed in the longitudinal direction and then in the width direction, the stretching in the longitudinal direction is divided into three or more steps, and the longitudinal stretching temperature is 80 ° C to 160 ° C and the total longitudinal stretching ratio is 3. 0-7.0
The double and longitudinal stretching speeds are 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 preferable, the stretching temperature is 80 to 200 ° C., the stretching ratio in the width direction is 3.0 to 7.0 times larger than the longitudinal ratio, and the stretching speed in the width direction is 1000 to 20000%. The range of / minute is preferred.

Next, this stretched film is heat-treated. In this case, the heat treatment temperature is 170 to 220 ° C. and the time is 0.5 to
A range of 60 seconds is preferred.

[0042]

EXAMPLES The present invention will be described in detail below with reference to examples. The characteristic values of the obtained film were determined according to the following methods.

(1) Average particle diameter Basically, the particles in the polyester composition are directly measured, but when the inorganic particles are used in combination and the distinction becomes complicated,
The average particle size was obtained from powder or slurry before being added to polyester.

(A) In case of measuring the average particle size from powder or slurry, the average particle size is placed on a sample stage of an electron microscope so that the particles are not overlapped as much as possible, and the result is measured with a scanning electron microscope or a transmission electron microscope.
The particles were observed at a magnification of 10,000 to 100,000 times. In the case of a scanning electron microscope, a platinum vapor deposition film having a layer thickness of about 200 angstrom was previously formed on the sample surface by a sputtering device. The area-equivalent diameter of at least 200 particles was measured from a screen or a photographic image, and the number-based average diameter and relative standard deviation were calculated.

(B) When measuring the average particle size and particle size ratio from the film: The film is cut in the longitudinal direction (MD direction) during film formation to prepare an ultrathin section having a thickness of about 0.1 μm, and the TD direction The cross section was observed with a transmission electron microscope at a magnification of 10,000 to 100,000 times from (the direction perpendicular to MD in the film plane). The number average value of the particle size ratio of at least 200 particles, the number-based average diameter and the relative standard deviation were calculated from a screen or a photographic image.

(2) Content of particles Calculated from the amount of particles incorporated into polyester, or the obtained polyester composition is dissolved in a solvent in which particles are insoluble, and the whole particles obtained by centrifuging from the polymer are obtained. The content (% by weight) was defined as the particle content.

(3) Lamination Thickness of Laminated Film Using a secondary ion mass spectrometer (SIMS), an element derived from the highest concentration of particles in the film in the depth range of 3000 nm from the surface layer and the polyester The concentration ratio (M ⁺ / C ⁻ ) of the carbon element is used as the particle concentration, and analysis is performed in the thickness direction from the surface to a depth of 3000 nm. In the surface layer, the particle concentration is low due to the interface of the surface, and the particle concentration increases as the distance from the surface increases. In the case of the film of the present invention, the particle concentration once reaching the maximum value starts to decrease again. Based on this concentration distribution curve, the depth at which the surface layer particle concentration becomes ½ of the maximum value (this depth is deeper than the maximum value) was determined and used as the laminated thickness. The conditions are as follows.

Measuring device Secondary ion quality analyzer (SIMS) Germany, ATOMIKA
Co., Ltd. A-DIDA3000 measurement conditions primary ion species O ₂ ⁺ primary ion acceleration voltage 12 kV primary ion current 200 nA raster region 400 μm □ analysis region gate 30% measurement vacuum level 6.0 × 10 ⁻⁹ Torr E-GUN 0. 5kV-3.0A In addition, when the particles contained most in the depth range of 3000 nm from the surface layer are organic polymer particles, it is difficult to measure by SIMS, so XPS (X
It is also possible to measure the depth profile in the same way as above by using line photoelectron spectroscopy), IR (infrared spectroscopy), etc., and determine the stack thickness. Also, by observing the cross section with an electron microscope, etc., changes in particle concentration and differences in polymers. It is also possible to recognize the interface from the difference in contrast due to and obtain the laminated thickness. Further, after peeling the laminated polymer, the laminated thickness can be obtained by using a thin film step measuring device.

(4) Smoothness of film surface The center line average roughness (Ra) was measured using a high precision thin film step measuring instrument ET-10 manufactured by Kosaka Laboratory. The measurement conditions are as follows, and the average value of 20 measurements was taken as the value. When Rt is 0.010 or less, the surface smoothness is good.

-Stylus tip radius: 0.5 μm-Stylus load: 5 mg-Measuring length: 1 mm-Cutoff value: 0.08 mm For details of the definition of each parameter, see, for example, Jiro Nara "Surface Roughness". "Measurement and evaluation method" (Comprehensive Technology Center, 1
983).

(5) Slipperyness of film Slit into film width 1/2 inch, tape running tester TBT-300 type [manufactured by Yokohama System Laboratory Co., Ltd.]
Was run at 20 ° C. and 60% RH, and the initial friction coefficient μk was determined by the following formula. The guide diameter is 6
mmφ, the guide material is SUS27 (surface roughness 0.
2S), winding angle is 180 °, traveling speed is 3.3 cm
/ Sec. μk = 0.733 × log (T ₁ / T ₂ ) T ₁ : Outgoing tension T ₂ : Incoming tension The above μk of 0.35 or less has good slipperiness.

(6) Abrasion resistance of film A tape-shaped roll obtained by slitting the film into 1/2 inch is wound around a guide roll made of stainless steel SUS-304 at an angle of 60 °, a speed of 250 m / min, and a tension of 95 g.
It was rubbed over 00 m and ranked as follows according to the amount of white powder generated on the surface of the guide roll. Grades A and B were accepted. Class A: No white powder is generated B Class: White powder is slightly generated C Class: White powder is slightly large D Class: White powder is large

Example 1 Dimethyl naphthalene-2,6-dicarboxylate 66.5 was added to a transesterification reactor equipped with a stirrer, a rectification column and a condenser.
Part, ethylene glycol 33.5 parts and magnesium acetate tetrahydrate 0.06 part, and then 180 ° C to 240 ° C.
The esterification reaction was carried out while the temperature was gradually raised to 0 ° C. and the methanol produced at the same time was continuously distilled out of the reaction system. To the thus obtained reaction product, 0.025 part of phosphoric acid trimethyl ester was added and reacted for 15 minutes, and then 0.02 part of germanium dioxide was added and further reacted for 5 minutes.

Subsequently, while continuously distilling ethylene glycol, the temperature was raised to 290 ° C. and, at the same time, 0.2 mmH
The polycondensation reaction is performed by reducing the pressure to g and the intrinsic viscosity is 0.6.
5 polymer (II) was obtained.

The chips were melted using a vent type twin-screw extruder, and ethyl vinylbenzene-divinylbenzene copolymer particles (average particle size 0.2 μm, relative standard deviation of particle size distribution) were used as organic polymer particles. 0.12, a particle size ratio of 1.0, and a thermal decomposition temperature of 380 ° C.) were added to obtain a polymer (II) containing organic polymer particles.

After drying the two polymers (I) and (II) under reduced pressure, the polymer (I) was added to the extruder 1 and the extruder 2.
After supplying (II), melting and high-precision filtration,
Three layers were laminated at the rectangular confluence (lamination structure: polymer (I
I) / Polymer (I) / Polymer (II)).

This was wound around a casting drum by an electrostatically applied casting method and cooled and solidified to prepare an unstretched film. This unstretched film is lengthwise 4.5
Double, 6.0 times in width direction, heat treated, total thickness 12μm
Was obtained.

From the particle concentration of the pellets used for film formation, the amount of organic polymer particles contained in the laminated portion of the obtained film was 0.2% by weight. The particles observed by using the obtained section of the film maintained the spherical shape, and no change was observed in the particle size ratio. The laminated thickness was 1 μm in both laminated parts.

The film had an Ra of 0.005, a μk of 0.31, and an abrasion resistance of class A, and had good characteristics in terms of surface smoothness, slipperiness, and abrasion resistance.

Examples 2 to 4 and Comparative Examples 1 to 4 Films were prepared in the same manner as in Example 1 except that the particle size, content, lamination conditions of the contained organic polymer particles or the polymer of the matrix were changed. Created. As shown in Table 1, within the range specified in the present invention, when the polyester film was used, good characteristics were obtained in terms of surface smoothness, slipperiness, and abrasion resistance, but if not, any of the characteristics was It was insufficient.

[0061]

[Table 1]

[0062]

The polyester composition of the present invention has excellent surface smoothness, slipperiness and abrasion resistance when formed into a film or the like,
It can be preferably used for magnetic recording media and the like.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C08K 5/49 KKC // (C08L 67/02 101: 00)

Claims (6)

[Claims] 1. An average particle diameter of 0.01 μm to 0.6 μm
A polyester containing 0.005 to 2.0% by weight of organic polymer particles having a particle size ratio (major axis / minor axis) of 1.0 to 1.5 and containing a magnesium compound or a manganese compound. A polyester composition containing at least one germanium compound and a phosphorus compound so as to satisfy the conditions of formulas (1) to (3), respectively. 0.01 ≦ M ≦ 0.15 (1) 0.005 ≦ Ge ≦ 0.15 (2) 0.5 ≦ M / P ≦ 5 (3) (wherein M, Ge, and P are each In the magnesium compound or manganese compound, germanium compound, phosphorus compound, magnesium or manganese, germanium, or phosphorus compound is shown as a mol% relative to a lower alkyl ester of dicarboxylic acid as each atom.) 2. The thermal decomposition temperature of the organic polymer particles is 350 ° C.
It is above, The polyester composition of Claim 1 characterized by the above-mentioned. 3. The polyester composition according to claim 1, wherein the average standard particle size of the organic polymer particles is 0.5 or less. 4. A film comprising the polyester composition according to claim 1. 5. A laminated polyester film comprising at least one layer of the polyester film according to claim 4. 6. The polyester is polyethylene-2,6-
It is naphthalate, The polyester composition or film of any one of Claims 1-5 characterized by the above-mentioned.