JP2001323140A - Polyester composition, film made thereof and magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester composition and a polyester film hardly causing bleedout and other problems encountered in a conventional method in which an additive is employed, excellent in molding properties and sliding properties and suitably employed for applications as a magnetic recording medium in particular. SOLUTION: The polyester composition is composed mainly of a polyester and has a peak ratio B of at least 5×10-3 and at most 500×10-3 and a (peak ratio B) to (peak ratio A) ratio of at least 0.7, where the peak ratio A is a quotient of a peak area within 1-3 ppm divided by a peak area within 4-6 ppm when the polyester composition is observed by the proton NMR and the peak ratio B is a quotient of a peak area within 1-3 ppm divided by a peak area within 4-6 ppm when a polyester composition, obtained by dissolving the polyester composition in a solvent and subsequently re-precipitating by diluting with toluene, is observed by the proton NMR.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composition having excellent surface properties, lubricity and heat resistance and particularly suitable for use as a base film for a magnetic recording medium.

[0002]

2. Description of the Related Art Conventionally, polyesters represented by polyethylene terephthalate have been widely used as fibers, films, and other molded products because of their excellent physical and chemical properties. Among these molded products, films are used for magnetic recording media, capacitors, food packaging, heat-sensitive stencil printing, and other general industrial uses. Various additives have been used for this purpose.

[0003] Also, particles are added to form appropriate irregularities on the surface of the film and to impart slipperiness and abrasion resistance.

As such additives, for example, polyolefins, higher fatty acids, fatty acid esters and the like have been used for a long time to impart lubricity. For example, JP-A-56-109245, Showa 57-2777
No. 7, JP-A-58-24848, JP-A-62-24
No. 179557 is known.

[0005]

However, since such an additive is contained as a component independent of the polyester, the compatibility state may become a problem,
When the compatibility state is poor, for example, when a stretched film is formed, a depression or coarse projections are formed, and the surface state is deteriorated. Even if the compatibility state is good, the additive component bleeds out at the time of molding, processing, or over time, impairing the surface properties, obstructing the processing step, and dyeing or coating. And the like, making high-order processing steps difficult, and changing the quality to impair the stability.

SUMMARY OF THE INVENTION The present invention solves the above problems, and particularly focuses on lubricity, and has excellent lubricity, excellent surface properties, and excellent heat resistance. It is intended to provide a use as a base film for a magnetic recording medium.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester composition containing a polyester as a main component and having a peak area in the range of 1 to 3 ppm as observed by hydrogen nuclei NMR of 4 to 4 ppm. The polyester composition was dissolved in a solvent, diluted with toluene, and reprecipitated. The polyester composition obtained by dividing by a peak area in the range of 6 ppm into a peak ratio A was 1 ~ 3
When the peak area in the range of ppm is divided by the peak area in the range of 4 to 6 ppm to obtain a peak ratio B, the peak ratio B is 5 × 10 ⁻³ or more and 500 × 10 ⁻³ or less, and
This is achieved by a polyester composition characterized by a peak ratio B / peak ratio A of 0.7 or more, or a film obtained from the composition.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The polyester used in the present invention is:
Examples thereof include those composed of a dicarboxylic acid component and a glycol component, and are produced by, for example, an esterification or transesterification reaction of a dicarboxylic acid or an ester-forming derivative thereof with glycol, and a subsequent polycondensation reaction.

The type of polyester is not particularly limited as long as it can be formed into a molded article such as a film. Suitable polyesters that can be molded into molded articles such as films include those using an aromatic dicarboxylic acid as the dicarboxylic acid component, such as polyethylene terephthalate, polyethylene-p-oxybenzoate,
Polyethylene-1,2-bis (2-chlorophenoxy)
Ethane-4,4'-dicarboxylate, polyethylene-1,2-bis (phenoxy) ethane-4,4'-dicarboxylate, polyethylene-2,6-naphthalenedicarboxylate, polybutylene terephthalate, polycyclohexane- 1,4-dimethylene terephthalate, etc., among which polyethylene terephthalate, polyethylene-2,6-naphthalenedicarboxylate, polybutylene terephthalate and poly-1,3-trimethylene terephthalate are preferred, and copolymers or blends thereof are preferred. A product is also a preferred embodiment.

[0010] Of course, these polyesters may be copolyesters. As the copolymerization component, an acid component such as an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and an alicyclic dicarboxylic acid other than the acid component and the glycol component constituting the polyester, an aromatic glycol, an aliphatic glycol and an alicyclic Glycol components such as glycols may be copolymerized, such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, phthalic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, 5-sodium Aromatic dicarboxylic acids such as sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, aliphatic dicarboxylic acids such as fumaric acid, 1,4-cyclohexanedicarboxylic acid, decalin dicarboxylic acid, etc. Alicyclic dicarboxylic acid It can be mentioned.

The glycol component includes ethylene glycol, 1,3-trimethylene glycol, 1,4-
Aliphatic glycols such as butanediol, 1,5-pentanediol, neopentyl glycol, diethylene glycol, 1,6-hexanediol, and 1,10-decanediol; 1,2-cyclohexanedimethanol;
Alicyclic glycols such as 4-cyclohexanedimethanol and hydrogenated bisphenol A can be mentioned.
Among these glycol components, ethylene glycol,
1,3-Trimethylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol are preferably employed.

The above-mentioned acid component and glycol component may be used alone or in combination of two or more. Further, these copolymer components may be by-produced when producing the polyester.

In the present invention, the amount of carboxy terminal groups in the polyester composition is preferably from 10 to 100 equivalents / ton. The lower limit is preferably 12 equivalents / ton, more preferably 15 equivalents / ton. The upper limit is preferably 80 equivalents / ton, more preferably 70 equivalents / ton. By setting the content in such a range, the heat resistance becomes good and the moldability is also effectively exerted.

The polyester composition containing the polyester of the present invention as a main component means a component other than the polyester component in the polyester, for example, a component forming a peak in the range of 1 to 3 ppm as observed by hydrogen nuclei NMR described later. This means that the composition may be combined, that is, a heterogeneous component may be contained in a small amount.

Next, the polyester composition of the present invention has a peak ratio A obtained by dividing a peak area in the range of 1 to 3 ppm by a peak area in the range of 4 to 6 ppm as observed by hydrogen nucleus NMR, and the polyester composition. Once dissolved in a solvent that dissolves the polyester composition such as orthochlorophenol and hexafluoroisopropanol, diluted with toluene and reprecipitated. The peak ratio B obtained by dividing the peak area in the range by the peak area in the range of 4 to 6 ppm needs to satisfy specific requirements.

That is, the peak ratio B is 5 × 10 ⁻³ or more,
The peak ratio B / the peak ratio A needs to be 500 × 10 ⁻³ or less, and the peak ratio B / peak ratio A needs to be 0.7 or more.

The lower limit of the peak ratio B is preferably 7 × 1
0 ^-3 , more preferably 10 × 10 ^-3 , particularly preferably 1
5 × 10 ⁻³ , and the upper limit is preferably 400 × 10 ⁻³ , more preferably 300 × 10 ⁻³ . If it is lower than this, the slipperiness is not sufficiently improved, and at most, not only the effect cannot be expected but also the moldability and heat resistance deteriorate. In particular, when the ^{concentration is} 15 × 10 ⁻³ or more, favorable moldability and easy film formation at a high speed are preferable.

The peak ratio A is not particularly limited, but the lower limit is preferably 5 × 10 ^-3 , more preferably 10 × 10 ^-3 , and the upper limit is preferably 600 × 1 ^-3.
0 ^-3, more preferably 500 × 10 ^-3, more preferably from 400 × 10 ^-3. By setting the content in such a range, an excellent film having good slipperiness and heat resistance can be obtained.

The value obtained by dividing the peak ratio B by the peak ratio A is more preferably 0.8 or more, still more preferably 0.9 or more.
Particularly preferably, it is 0.95 or more. For the upper limit,
There is no particular limitation, but it is preferably about 1.0. By having such a range, there is no bleed-out or the like even in a long-term heat history, and particularly when used as a magnetic recording medium, the formation of coarse protrusions on the surface of the magnetic layer is suppressed, and the heat resistance is also good and excellent. A film having characteristics can be obtained.

The method for measuring the nuclear hydrogen NMR is as follows.
This is described in detail in the following examples.

When the polyester composition is dissolved in a solvent, if there is any insoluble matter other than the polyester composition, filtration may be performed. In the present invention, toluene is used as a reprecipitation solvent. This is for separating and concentrating the polyester component, and when components other than the polyester are simultaneously precipitated, changing the reprecipitation solvent,
Washing the reprecipitated component with another solvent that does not dissolve the polyester component is equivalent in view of the technical idea of the present invention.

Usually, in hydrogen nuclear NMR, 1-3 ppm
Peaks in the range of (cyclo) alkyl group, (cyclo)
The peak is caused by an alkylene group, a (cyclo) alkyne group, or the like. In the present invention, the peak is preferably substantially caused by a monovalent alkyl group. In such a case, the slipperiness is further improved.

Although the mechanism of action of the present invention is not necessarily clear, considering the compatibility and the change in free energy during the formation of crystals, the structure accumulates in the amorphous portion of the polyester, and the domains having good slipperiness are extremely microscopic. It seems to be because it is dispersed.

As a method of analyzing the composition of the peak component, it is possible to examine and analyze the NMR spectrum in detail. For example, after the polyester composition component is subjected to a solvolysis step such as methanolysis, , Using high-performance liquid chromatography and other analytical methods to separate components,
It is also possible to ask.

In the present invention, when the polyester composition is subjected to thermogravimetric analysis under a nitrogen atmosphere at a heating rate of 20 ° C./min, the thermogravimetric loss before reaching the melting point, usually in the range of 200 ° C. to 300 ° C. It is preferably at most 0.3% by weight. It is more preferably at most 0.2% by weight, further preferably at most 0.15% by weight, particularly preferably at most 0.1% by weight. There is no particular lower limit, but 0.03% by weight
It is about. The polyester composition is often molded under melting, but when such conditions are satisfied, the processability is excellent and the quality of the product is improved. In addition, it can withstand long-term film formation and is excellent in productivity.

In the present invention, it is a preferred embodiment to include inert particles for further improving the slipperiness, and a synergistic action can be obtained. The inert particles mentioned here are particles that are incompatible with the polyester even if a part thereof.

The inert particles contained in the present invention are not particularly limited as long as the requirements of the present invention can be satisfied as a final composition. Silicon, aluminum, zinc, iron, titanium, zirconium, molybdenum, cerium, yttrium Inorganic particles such as oxides, sulfides, sulphates, nitrates, halides, carbonates, phosphates and the like, tin, barium, calcium, magnesium, sodium, potassium, etc., styrene derivatives, (meth) acrylic acid derivatives, Organic particles containing a vinyl resin such as a chlorinated vinyl derivative or a vinyl alcohol derivative, a fluororesin, a silicone resin, or the like as a component can be exemplified. Among them, oxides of silicon, aluminum and zirconium or styrene-based resins and silicone resins having good slipperiness, abrasion resistance and heat resistance can be obtained. Further, it is preferable to use spherical particles, and it is preferable that the thermogravimetric analysis under a nitrogen atmosphere has a heat loss at 350 ° C. of 1% by weight or less.

The use of such inert particles in a content of 0.005 to 5% by weight is preferred from the viewpoint of slipperiness.

The average particle size of the inert particles is as follows:
0.005 to 20 μm is preferred. The lower limit is preferably 0.1 μm, and more preferably 0.2 μm. Further, the upper limit is preferably 15 μm,
More preferably, it is 10 μm, particularly preferably 5 μm
It is. The present invention can be suitably processed into a film or a sheet-like material. At this time, if the average particle diameter is equal to or more than the lower limit, good characteristics in terms of slipperiness and abrasion resistance can be obtained. Also, if it has an average particle size equal to or less than the upper limit, the effect on the surface configuration when performing surface processing such as falling off of particles in the processing step and application of a coating material becomes negligible, Good yield and good product quality.

The present invention does not prevent the incorporation of two or more types of inert particles (including those having the same chemical composition and different average particle diameters). Rather, the wear resistance and the slipperiness are further improved. Therefore, it is preferably adopted.

Next, embodiments of the present invention will be specifically described with reference to examples, but the present invention is not limited to the description.

In the synthesis of the polyester, for example, a so-called transesterification method using a dialkyl ester of an aromatic dicarboxylic acid and ethylene glycol or a direct polymerization method in which a dicarboxylic acid and ethylene glycol are directly reacted is preferably employed.

Known catalysts and the like can be used. For example, an alkali metal acetate is used as a transesterification catalyst, and an antimony oxide catalyst containing little germanium oxide or bismuth is used as a polymerization reaction catalyst. Among them, it is preferable to employ a germanium oxide catalyst. Further, a combination use of a transition metal compound such as cobalt or an alkoxy titanate can be preferably employed.

For the purpose of improving heat resistance, phosphorus compounds such as trialkyl phosphate, monoalkyl phosphate, phosphoric acid, phosphorous acid, dialkylarylphosphonate, and carboalkoxyalkenyldialkylphosphonate are preferred. Can be blended.

Next, in order to obtain the polyester composition of the present invention, in the reaction step, when a functional group having a reactive activity to a carboxyl group or a hydroxyl group constituting the polyester is observed by hydrogen nuclei NMR, 3 ppm
It is effective to react a compound to which a component expressing a peak is bound.

Such compounds include, for example, aliphatic (mono or poly) alcohols, aliphatic (mono or poly) carboxylic acids, aliphatic (mono or poly) amines, aliphatic (mono or poly) amides, Aliphatic (mono or poly) isocyanates, aliphatic (mono or poly) thiols, aliphatic (mono or poly) epoxides, aliphatic (mono or poly) and heterogeneous functional groups combined, or lactones, lactams, Cyclic compounds such as imides may be mentioned, but aliphatic (mono or poly) alcohols and aliphatic (mono or poly) carboxylic acids are preferably used in view of moldability and heat resistance.

The aliphatic moiety, that is, the (cyclo) alkyl group, the (cyclo) alkene group, and the (cyclo) alkyne group preferably have 8 to 30 carbon atoms.
The lower limit is preferably 10, more preferably 12, and particularly preferably 14, and the upper limit is 2
6, more preferably 24, particularly preferably 20.
When the above compound is used, the compound strength or molecular weight of the polyester portion when used as the above compound is a factor influencing the polymerization reactivity.By setting the above range, the moldability and the slipperiness are sufficient, and the heat resistance is also improved. A polyester composition having good properties and mechanical properties can be obtained.

When a compound as described above is used, its vapor pressure at 200 ° C. is preferably 200 Pa or less, more preferably 100 Pa or less, particularly preferably 50 Pa or less. Although the lower limit is not particularly limited, it is practical to be about 0.01 Pa from the viewpoint of handleability.

When the above-mentioned compounds are used, the timing of their addition is important together with the design of the reaction system. In the present invention, for example, when the polyester is polyethylene terephthalate, the intrinsic viscosity is 0.05 to 0.1.
It is preferred to add between 8. The lower limit is more preferably 0.1, still more preferably 0.3, particularly preferably 0.4, and the upper limit is more preferably 0.7,
More preferably, it is 0.65. If the addition time is too late, the degree of polymerization is difficult to increase, moldability and mechanical properties are likely to be impaired, and it does not remain in the reprecipitated polyester, so that the effects of the present invention cannot be sufficiently obtained, and the compound itself or a derivative thereof May be deposited when heated, and the effect of the invention may not be sufficiently obtained, or the process may be soiled at the time of molding or processing into a film or the like, which may impair productivity. On the other hand, if the addition time is early, low molecular weight compounds are likely to be produced, bleeding out when heated, making it difficult to obtain the effects of the present invention, and fouling the process at the time of molding or processing into a film or the like. Therefore, productivity may be impaired. In the case of other polyesters, the addition time may be appropriately adjusted to obtain the polyester composition of the present invention.

When the compound is added, the compound is preferably filtered once and then added, and the filter is preferably a filter which does not filter foreign substances of 2 μm or more or cuts foreign substances of 1 μm or more by 90% or more. It is preferable to use When the filter is used, the surface property becomes very good, and the application to a vapor-deposited magnetic recording medium to be described later becomes particularly suitable.

After the addition, it is preferable to continue the polymerization reaction again, so as to obtain a preferable intrinsic viscosity, and it is possible to sufficiently disperse or react the above-mentioned compound in the polyester, and to prepare a final polyester composition. can do.

The polyester composition of the present invention has an intrinsic viscosity of preferably 0.45 g / dl or more, more preferably 0.5 g / dl or more, and particularly preferably 0.55 g / dl.
1 or more. The upper limit is not particularly limited, but is about 1.2 g / dl from the viewpoint of workability. By setting the content in such a range, the moldability can be further improved.

When the particles are incorporated, the method is not particularly limited, but may be a method of adding the particles before or during the polymerization step, or a method of adding the slurry to a single or twin screw kneader equipped with a vent port after the polymerization. And a method of mixing a separately prepared particle-containing polyester composition under melting, and a method of adding during the polymerization step or a method of separately preparing the particle-containing polyester composition under melting. The method of mixing is preferable in that it can be easily carried out.

The polyester composition of the present invention thus prepared can be formed by a known method. For example, a specific method for producing a film comprising the polyester composition of the present invention will be described.After drying the polyester composition, it is melt-extruded to form an unstretched sheet, and then biaxially stretched, heat-treated to form a film. Method.
The biaxial stretching may be any of longitudinal and transverse sequential stretching or simultaneous biaxial stretching. The stretching ratio is usually 2.0 in each of the vertical and horizontal directions.
~ 5.0 times is appropriate. After the biaxial stretching, the film may be further stretched in any of the longitudinal and transverse directions. Inert particles can be blended by appropriately mixing each particle raw material-containing polyester or a polyester resin containing no particles. As the stretching conditions, an embodiment in which stretching is performed at a low temperature of Tg + 100 ° C. or lower or at a speed of 2000% / minute or more is preferably adopted.

When the present invention is embodied as a laminated film, for example, a plurality of feeders and extruders are prepared, each raw material is charged and melted, and then laminated and extruded using a pinol or the like during melt molding. It can be obtained or cast on top of it after being formed. In the former case, the lamination thickness can be adjusted by making the melt viscosity of the raw materials as equal as possible and controlling the amount extruded from each extruder. It is important that the polyester composition of the present invention is used in at least one of the outermost layers from the functional aspect as well.

The thickness unevenness of the film of the present invention relative to the total film thickness is preferably 20% or less, more preferably 14% or less, and further preferably 10% or less. The lower limit is not particularly limited, but is about 2% from the viewpoint of productivity. When the thickness unevenness exceeds 20%, the quality as a molded article is inferior, and there is a concern that workability and flatness may deteriorate.

Further, the film of the present invention preferably has 20 or less depressed defects having an equivalent circle diameter of 1 μm or more on the surface containing the composition of the present invention, not more than 20 / mm ^2.
0 / mm ² or less, more preferably 5 / m 2
More preferably, it is not more than m ² . When different components are contained, the deformability under the stretching stress is different, so that a depression or a projection is often formed. In the constitution of the present invention, since there is a large amount of compounding between the additive and the polyester, it can be suppressed preferably, and a fine surface is formed, and a film suitable particularly for a vapor deposition tape can be obtained. Although the lower limit is not particularly defined, it is preferable that such a depression defect is not formed.

The polyester composition of the present invention and a film comprising the same may contain other thermoplastic resins such as polyethylene, polypropylene, polystyrene and the like, and various additives such as carbodiimide and epoxy compound, as long as the purpose is not impaired. Terminal blocking agents, ultraviolet absorbers, antioxidants, antistatic agents, surfactants, pigments, optical brighteners and the like.

Further, a coating layer can be formed on the film of the present invention, if necessary. For the formation of the coating layer, there is a method of forming the coating layer at any time during the film forming process or off-line after forming the film, but since there is little concern that scratches are generated and the productivity is good, it is necessary to coat at the time of film formation. Is preferred. For example, there is a method in which a coating agent is applied using a metalling bar or a gravure coater after casting / stretching, and drying / stretching is performed simultaneously.

The preparation of the coating agent may be performed by a known method. The refractive index of the coating composition is influenced by the composition of the coating composition, drying conditions, stretching conditions, and the like. However, the composition can be easily adjusted by using a crosslinked acrylic or urethane-based coating agent because the adjustment range can be set flexibly. .

Next, when obtaining a magnetic recording medium, Co, N
i, a method of applying a solution of a binder resin such as urethane or acrylic containing magnetic powder such as ferrite to at least one surface of a film, drying and calendering the film, and forming a lubricant-containing resin layer if necessary (coating type Magnetic recording medium), a magnetic metal is deposited on at least one surface of the film to form a magnetic metal thin film layer, and if necessary, a protective layer and a lubricating layer are formed, and if necessary, on a surface opposite to the surface on which the magnetic surface is formed. A method of providing a slippery layer (a vapor-deposited magnetic recording medium) may be used. When it is made into a tape, it can be obtained by cutting into a tape shape. In the present invention, because it has excellent lubricity and surface properties at the same time, high surface accuracy is required,
It can be preferably used for a vapor deposition type magnetic recording medium suitable for high density recording.

[0052]

EXAMPLES The present invention will be described in detail with reference to examples, but the present invention is not limited by the following examples. The characteristic value was measured by the following method in the present invention.

A. Average particle size of particles The cross section of the polyester composition is examined by a transmission electron microscope (TE
Observe at a magnification of 10,000 or more using M). The thickness of the section of the TEM is about 100 nm, and measurement is performed in 100 or more visual fields at different locations. The average diameter d of the particles is determined as an equivalent circle equivalent diameter.

B. Particle Content The polyester composition is dissolved in orthochlorophenol, and insoluble components are separated by a centrifuge. The separated product was washed, dried to a constant weight, and determined as a weighed value.

C. Peak ratio The polyester composition is freeze-pulverized into a powdery substance, dissolved in a mixed solvent of hexaisopropanol-deuterochloroform, and subjected to an H-NMR spectrometer (GSX-4 manufactured by JEOL Ltd.).
00) (peak ratio A).

On the other hand, the polyester composition is dissolved in hexafluoroisopropanol (HFIP), and first, insoluble matter is filtered off. Then, toluene was gradually added to the filtrate, and when the required amount of polymer precipitation was measured, the addition was stopped and the mixture was filtered off. The filtrate was mixed with a methanol / HFIP mixed solvent,
Then, it was washed several times with methanol and dried. After drying, the sample was measured in the same manner as the peak ratio A to determine the peak ratio (peak ratio B).

In the calculation of the peak ratio, peaks corresponding to solvents and impurities were subtracted.

D. Analysis of solvolysates The polyester composition was subjected to methanolysis using methanol, and components were separated by high performance liquid chromatography. The structure and weight of each separated product were obtained and calculated.

E. Thermogravimetric reduction A sample is weighed, and a thermogravimetric analyzer (T
GA-50) in a nitrogen atmosphere at a heating rate of 20 ° C. /
In minutes, the temperature was raised from room temperature to 350 ° C., and the heat loss at 300 ° C. was determined by taking the point of 200 ° C. as a zero point in consideration of the influence of moisture absorption.

F. Intrinsic viscosity of polyester composition Using o-chlorophenol as a solvent, the intrinsic viscosity was measured at a measurement temperature of 25 ° C. using an Oswald viscometer.

On the other hand, the intrinsic viscosity at the time of addition was determined by preparing a calibration curve between the stirring torque and the intrinsic viscosity and converting from the stirring torque.

G. Carboxy terminal group amount The polymer was dissolved in a mixed solvent of ortho-cresol / chloroform (weight ratio 7: 3) at 90 to 100 ° C, and determined by potentiometric titration using an alkali.

H. The thickness of the film was measured at least 500 points arbitrarily sampled from the film roll, and the thickness was determined by the following formula (maximum thickness−minimum thickness) / average thickness × 100 (%)

I. Film Lamination Thickness The depth direction distribution of the particle concentration is measured using a secondary ion mass spectrometer, X-ray photoelectron spectroscopy, infrared analysis, or a confocal microscope. After obtaining a maximum value in the depth direction with respect to the surface, a depth that is の of the maximum value was defined as a lamination thickness. In addition, when the lamination thickness is small, it can be determined not only from the depth distribution of the particle concentration but also from the observation of the cross section of the film or a thin film level difference measuring instrument.

J. Number of Depressed Defects Aluminum was vapor-deposited on the obtained film, the surface was observed with a differential interference microscope, counted for 10 visual fields, and the average value was obtained.

K. Slip property of film It was obtained as a dynamic friction coefficient. The coefficient of kinetic friction (μk) is calculated by using a film with a dynamic friction coefficient (TBT-300) manufactured by Yokohama Seisakusho.
8 m outside diameter in an atmosphere of 25 ° C. and 50% RH
After making contact with a SUS420J mφ post having a surface roughness of 0.2S at a winding angle of 180 ° and moving at a speed of 3.3 cm / sec, the tension is controlled so that the entry-side tension T1 becomes 25 g. From the value of the output side tension T2 (g), it was determined by the following equation: μk = (2 / π) ln (T2 / T1).

L. Blocking property After the roll-shaped film 10000 m is rewound under vacuum, it is opened to the atmosphere and then exposed to an atmosphere of 25 ° C. and 60% RH.
Every other day, then the film was unwound at a speed of 140 m / min. The behavior of the film at that time was determined based on the following criteria. No pulling of the film is observed at all: ◎ The film is slightly pulled, but no change is observed in the roll shape after unwinding: ○ The film is dragged and the roll shape after unwinding is deteriorated: Δ: The film is pulled and tears occur: x.

M. Number of dropouts Cobalt-nickel alloy (Ni 20% by weight) in the presence of a trace amount of oxygen using a continuous vacuum evaporation system on the film surface
Was formed (200 nm). Next, a carbon protective film and a fluorine-based surfactant are applied to the surface of the deposition layer,
After providing the back coat layer on the opposite side, it is cut into 8 mm width,
I made a pancake. Next, a 200 m length of this pancake was incorporated into a cassette tape.

This cassette tape was converted to a commercially available VT for Hi8.
Evaluation was performed using R. 3. From TV test signal generator
A 4 MHz signal is supplied, and a reproduction signal attenuation is -16 dB or more and a length is 15
The number of dropouts of μsec or more was determined. 25
The number of dropouts after repeating reproduction / rewind 100 times for 3 minutes at 65 ° C. and 65% RH was converted to the number per minute and judged as follows. 0 to 15 pieces / min: １６ 16 to 30 pieces / min: 31 pieces / min: ×.

Filtration operation Commercially available stearyl stearate, decalyl decalate,
Thaw each of the behenyl behenates, 2μ
m, pass through a 100% cut pleated filter,
Each filtered product was prepared.

Example 1 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol were subjected to a transesterification reaction using 0.09 parts by weight of lithium acetate as a catalyst according to a conventional method.

Thereafter, 0.08 part by weight of antimony trioxide and 0.1 part by weight of trimethyl phosphate as a phosphorus compound were added, and subsequently a polycondensation reaction was carried out in accordance with a conventional method to reach an intrinsic viscosity of 0.5 g / dl. At this point, the pressure was once returned to normal pressure, and stearyl stearate was added at 2% by weight based on the weight of the polymer. After stirring for 5 minutes, the pressure was reduced again to continue the polycondensation reaction. The intrinsic viscosity of the obtained polyester composition is 0.60 g / dl, the amount of carboxy terminal groups is 30.2 equivalent / ton, the peak ratio A and the peak ratio B are 78 × 10 ⁻³ , 74 × 10 ⁻³ , respectively, The weight loss was 0.08% by weight (polyester A).

Further, after the transesterification reaction, the average particle size is 0.1 mm.
The above polyester A was added except that 3 μm of 20% by weight of colloidal silica ethylene glycol slurry (manufactured by Kako Kasei Kogyo Co., Ltd.) was added as 2% by weight to the polyester resin, and no stearyl stearate was added.
A slippery polyester composition was obtained using the same preparation method as in (Polyester B).

Further, using the same preparation method as the above-mentioned polyester A except that stearyl stearate was not added,
A polyester composition for dilution was obtained (Polyester C).

Next, each of the polyesters A, B and C is sufficiently dried and mixed so that polyester A / polyester B / polyester C = 25/10/65.
It was supplied to an extruder, melted at 285 ° C., extruded from a T-type die into a sheet, and cooled and solidified with a cooling drum at 30 ° C. to obtain an unstretched film. Next, the unstretched film was simultaneously stretched 3.0 times in the longitudinal direction and 3.0 times in the transverse direction at 100 ° C., and then heat-treated at 200 ° C. to obtain a film having a total thickness of 7.5 μm. The properties of the obtained polyester film are shown in Table 1.

Next, Co powder 1 was applied to one surface of the film.
00 parts, polyurethane resin 15 parts by weight, vinyl chloride / vinyl acetate copolymer resin 5 parts, nitrocellulose resin 5
Parts, aluminum oxide powder (average diameter 0.3 μm) 3 parts,
A magnetic paint having a composition of 100 parts of methyl ethyl ketone, 100 parts of toluene and 2 parts of stearic acid is applied, dried and heat-cured,
Next, a back coat layer containing carbon black and a thermosetting urethane resin is formed on the back surface, slitted,
A magnetic tape was obtained. The film had good slipperiness and exhibited good electromagnetic conversion characteristics.

Example 2 Two extruders were prepared, and one layer was composed of the polyester A, polyester B and polyester C used in Example 1 above.
In the other layer, polyester C was laminated so that the final film thickness was 1.5 μm and 6 μm, respectively, and a film was obtained in the same manner as in Example 1 below.

Then, a water-soluble coating layer composed of a water-soluble polyester resin, a silane coupling agent, colloidal silica particles of 20 nm, and carboxymethylcellulose was applied to the film surface side composed of only the polyester C layer and dried to obtain a film.

Next, the film roll was placed on a vacuum evaporation machine, and a Co—Ni film was formed on the coating layer surface side.
Further, a protective layer (diamond carbon film) and a lubricating layer were formed on the deposition surface by a known method. On the opposite side, a back coat layer containing carbon black and a thermosetting urethane resin was formed, slit, and a magnetic tape was obtained. The results obtained are shown in Table 1.

Example 3 Polyester A was prepared in the same manner as in Example 1 except that the stearyl stearate was added when the intrinsic viscosity in the system reached 0.35 g / dl.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Example 4 Example 1 was repeated except that the stearyl stearate was added when the intrinsic viscosity of the system reached 0.1 g / dl.
Polyester A was prepared in the same manner as described above.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Example 5 Polyester A was prepared in the same manner as in Example 1 except that decalyl decalate was used instead of stearyl stearate.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Example 6 Polyester A was prepared in the same manner as in Example 1 except that behenyl behenate was used instead of stearyl stearate.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Example 7 Dimethyl 2,6-naphthalenedicarboxylate was used in place of dimethyl terephthalate, and the amount added was determined on the basis of the molar ratio. Stearyl stearate was 1% by weight per polymer when the intrinsic viscosity was 0.6. %, And polyester A was prepared in the same manner as in Example 1.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Comparative Example 1 Two extruders were prepared. One extruder was made of the polyesters B and C used in Example 1 above, and the other extruder was made of the polyester C as the final film thickness.
The layers were laminated so as to have a thickness of 5 μm and 6 μm, and a film was obtained in the same manner as in Example 1 below.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Comparative Example 2 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol were subjected to a transesterification reaction using 0.09 part by weight of lithium acetate as a catalyst according to a conventional method.

Thereafter, 0.08 part by weight of antimony trioxide and 0.1 part by weight of trimethyl phosphate as a phosphorus compound were added, and subsequently a polycondensation reaction was carried out in accordance with a conventional method to reach an intrinsic viscosity of 0.67 g / dl. At this point, the pressure was once returned to normal pressure, and stearyl stearate was added as 1% by weight based on the weight of the polymer. After stirring for 5 minutes, polycondensation was performed again to prepare polyester A.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Comparative Example 3 Polyester A was prepared in the same manner as in Example 1 except that a commercially available polyethylene wax was used instead of stearyl stearate.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Comparative Example 4 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol were subjected to a transesterification reaction in the usual manner using 0.09 part by weight of lithium acetate as a catalyst.

Thereafter, 0.08 part by weight of antimony trioxide and 0.1 part by weight of trimethyl phosphate as a phosphorus compound were added, and subsequently a polycondensation reaction was carried out in accordance with a conventional method to reach an intrinsic viscosity of 0.80 g / dl. At this point, the pressure was once returned to normal pressure, and stearyl stearate was added at 2% by weight based on the weight of the polymer, followed by stirring for 5 minutes to prepare polyester A.

Next, a film and a magnetic tape were obtained in the same manner as in Example 2. The results obtained are shown in Table 1.

Comparative Example 5 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol were subjected to a transesterification reaction in the usual manner using 0.09 part by weight of lithium acetate as a catalyst.

Thereafter, stearyl stearate was added so as to be 2% by weight based on the weight of the polymer, and after stirring for 5 minutes, 0.08 part by weight of antimony trioxide and 0.1 part by weight of trimethyl phosphate as a phosphorus compound were added. Subsequently, an attempt was made to carry out a polycondensation reaction according to a conventional method. However, some time after the start of the polymerization, a rise in the liquid level was observed, and deposits were deposited on the reduced pressure system, so that the polymerization could not be continued.

[0102]

[Table 1]

[0103]

The present invention has excellent surface properties, lubricity, and heat resistance, and can be used to improve product quality, molding process, and processing process by bleeding out during molding or processing by the conventional additive method. Various problems due to contamination or aging can be solved.

The composition of the present invention can be processed and applied to various forms as fibers, sheets, films and moldings due to its excellent properties, and exhibits excellent effects particularly when formed into a film. The film can be suitably used for the above-described magnetic recording medium, particularly, a vapor deposition type magnetic recording medium. In addition, the base film for ink ribbons, the bonding of metal plates such as drinking cans and building materials, and the exterior material of electric equipment For capacitors, carrier films for electronic components,
It can be used for various general industrial uses, such as bonding to glass members and heat-sensitive stencil printing. In addition, they have excellent processing characteristics and are excellent in product yield.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA45 AB08 AB22 AB24 AB26 AH14 BA01 BB06 BB08 BC01 4J002 BC022 BD032 BD122 BE012 BG012 BG022 CF031 CF041 CF061 CF071 CF081 CP032 DD026 DE056 DE076 DE086 DE106 DE116 DE136 DE26 DG 146 DG FD060 FD176 5D006 CB01 CB05 CB07 CB08 FA00

Claims (9)

[Claims] 1. A polyester composition containing a polyester as a main component, wherein the polyester composition has a composition of 1 to 3 as observed by hydrogen nuclei NMR.
The peak ratio in the range of 4 to 6 ppm divided by the peak area in the range of 4 to 6 ppm is defined as a peak ratio A, and the polyester composition obtained by dissolving the polyester composition in a solvent, diluting with toluene and reprecipitating the polyester composition is obtained. When a peak ratio B obtained by dividing a peak area in a range of 1 to 3 ppm observed by hydrogen nuclear NMR by a peak area in a range of 4 to 6 ppm,
A polyester composition having a peak ratio B of 5 × 10 ⁻³ or more and 500 × 10 ⁻³ or less, and a peak ratio B / peak ratio A of 0.7 or more. 2. The polyester composition according to claim 1, wherein the peak in the range of 1 to 3 ppm is substantially caused by a monovalent alkyl group. 3. When the polyester composition is subjected to thermogravimetric analysis under a nitrogen atmosphere at a heating rate of 20 ° C./min.
The polyester composition according to claim 1 or 2, wherein the thermogravimetric loss in the range of 00 ° C is 0.3% by weight or less. 4. The polyester composition according to claim 1, which contains inert particles. 5. A polyester film obtained by using the polyester composition according to claim 1. 6. A laminated polyester film comprising the polyester film according to claim 5 in at least one layer. 7. The polyester film according to claim 5, wherein the number of depression defects having an equivalent circle diameter of 1 μm or more on the film surface is 20 pieces / mm ² or less. 8. A magnetic recording medium comprising a magnetic recording layer provided on at least one side of the polyester film according to claim 5. 9. The magnetic recording layer is a magnetic metal thin film.
3. The magnetic recording medium according to claim 1.