JPH05156145A - Polyester composition, its production, and film therefrom - Google Patents

Abstract

PURPOSE:To provide a polyester compsn. giving a film excellent in slipperiness, surface uniformity, clarity, and abrasion resistance by compounding specific cross-linked polymer particles into an arom. polyester obtd. by the copolymn. of a sulfonated compd. with other necessary comonomers. CONSTITUTION:An arom. polyester having at least one sulfonic acid group or metal sulfonate group is melt mixed on a vented molding machine with a slurry consisting of cross-linked polymer particles, a water-sol. high-molecular compd., and water or an org. compd. having a b.p. of 200 deg.C or lower.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composition in which crosslinked polymer particles maintain a uniform monodisperse state even when the molten state is maintained for a long time, a process for producing the same, and a film.

[0002]

2. Description of the Related Art Polyester, especially polyethylene terephthalate, is widely used as a fiber, a film and other molded articles because of its excellent physical and chemical properties. However, contrary to its excellent characteristics, undesired troubles such as deterioration of workability due to poor processability in the molding step for obtaining the above-mentioned molded product or slipperiness in handling of the product itself, reduction of product value occur. It is also known.

To address these problems, a number of methods have been proposed, in which fine particles in polyester are contained to impart appropriate irregularities to the surface of a molded article to improve the slipperiness of the surface of the molded article, some of which have been proposed. It has been put to practical use. For example, inert inorganic particles such as silicon oxide, titanium dioxide, calcium carbonate, talc, and kaolinite, or organic high-content resins such as benzoguanamine / formaldehyde resin, polytetrafluoroethylene-hexafluoropropylene copolymer, and polyphenyl ester resin. There is a method of adding molecular fine particles to a polyester synthesis reaction system (for example, JP-A-55-133).
431, JP-A-57-125247, etc.).

However, the method of adding the inert inorganic particles generally has a poor affinity with polyester, and when formed into a film, for example, voids are formed around the particles. Also,
Coarse particles are often mixed, and even if pulverization and classification operations are performed to remove them, it is inevitable to mix coarse particles. When voids are generated or coarse particles are present in this way, for example, for plate-making printing, transparency is significantly reduced in a film for which transparency is required, such as for a microfilm, and in a film for a capacitor, electrical characteristics are reduced. Adversely affect. Further, in a film for a magnetic tape, it causes a deterioration in electromagnetic conversion characteristics or causes dropout, which impairs film quality.

On the other hand, the method of adding fine organic polymer particles generally has good affinity with polyester, but it is difficult to obtain uniform fine particles, and even if they are obtained, they are agglomerated in the polyester. Due to poor dispersibility, it is inevitable to mix coarse particles.

In recent years, higher quality has been demanded for films requiring transparency, films for capacitors, films for magnetic tapes, etc., and particles having a uniform film surface with easy sliding properties and excellent affinity with polyester. A film containing is desired. Therefore, the present inventors have improved the drawbacks of the above-mentioned conventionally used particle addition method, in particular, to obtain a polyester film having excellent lubricity and film surface uniformity, transparency, and abrasion resistance. As a result of intensive study, by combining a polyester having a specific functional group with crosslinked polymer particles treated with a specific compound,
It has been found that the cross-linked polymer particles maintain a uniform monodisperse state even after being melt-held for a long time, and it has been found that the above-mentioned object can be achieved.

[0007]

DISCLOSURE OF THE INVENTION The object of the present invention is that the crosslinked polymer particles are uniformly monodispersed in the polyester, and are maintained in this state even after being melt-held for a long time. It is to provide a polyester composition having excellent slipperiness, surface uniformity, transparency, and abrasion resistance that cannot be achieved by the above, a method for producing the same, and a film.

[0008]

The above-mentioned object of the present invention is achieved by the following constitution.

(1) An aromatic polyester (A) obtained by copolymerizing a compound having at least one sulfonic acid group or a metal sulfonate group, and a part or all of the surface thereof is coated with a water-soluble polymer compound. Crosslinked polymer particles (B)
A polyester composition comprising:

(2) In a vent-type molding machine, the crosslinkable polymer particles (roller) are added to the aromatic polyester (a) having at least one sulfonic acid group or metal sulfonate group.
1) and water of the water-soluble polymer compound (b-2) or a slurry (b) of an organic compound having a boiling point of 200 [deg.] C. or less is added to the method for producing a polyester composition.

(3) A biaxially oriented polyester film comprising the polyester composition of (1) above.

(4) A biaxially oriented laminated film characterized in that the polyester composition of the above (1) is laminated on at least one side.

(5) In the above (4), the film thickness of the laminated portion is 0.1 to 0.1 of the average particle diameter of the crosslinked polymer particles (B).
10 times, the content of the particles is 0.01 to 20 parts by weight with respect to 100 parts by weight of the polymer of the laminated part, a biaxially oriented laminated film.

The aromatic polyester (A) obtained by copolymerizing a compound having at least one sulfonic acid group or a metal sulfonate group in the present invention means an aromatic dicarboxylic acid or its ester-forming derivative (a) and It is a polyester whose main component is a compound (c) having at least one glycol (b) and a sulfonic acid group, or a sulfonic acid metal base.

Specific examples of the aromatic dicarboxylic acid or its ester-forming derivative (a) include terephthalic acid and
2,6-naphthalenedicarboxylic acid, 1,2-bis (chlorophenoxy) ethane-4,4′-dicarboxylic acid, dimethyl terephthalate as an ester-forming derivative thereof,
Examples thereof include dimethyl 2,6-naphthalenedicarboxylate and dimethyl 1,2-bis (chlorophenoxy) ethane-4,4′-dicarboxylate, and among them, terephthalic acid or dimethyl terephthalate is preferable.

Examples of the glycol component (b) include ethylene glycol, butylene glycol, diethylene glycol, propylene glycol, polyethylene glycol, 1,4-cyclohexanedimethanol and the like, among which ethylene glycol is preferred.

The compound (c) having at least one sulfonic acid group or metal sulfonate group is 5
-Sodium sulfoisophthalic acid and its ester-forming derivative, 5-lithium sulfoisophthalic acid and its ester-forming derivative, 5-sodium sulforesorcin, and the like. Among them, 5-sodium sulfoisophthalic acid and its ester-forming derivative, 5-Lithium sulfoisophthalic acid and its ester-forming derivatives are preferred.

The amount of the compound (c) copolymerized is 100 parts by weight of the aromatic dicarboxylic acid or its ester-forming derivative (a) from the viewpoint of dispersion stability when the crosslinked polymer particles are held in a molten state. On the other hand, it is preferably 0.1 part by weight or more. From the viewpoint of handling as a film and dispersion stability of particles, the copolymerization amount of the compound (c) is 10 parts by weight or less, preferably 100 parts by weight or less, based on 100 parts by weight of the aromatic dicarboxylic acid or its ester-forming derivative (a). Is preferably 8 parts by weight or less, more preferably 6 parts by weight or less.

Besides this, other components may be copolymerized. Examples of the component include diol components such as neopentyl glycol, polyalkylene glycol and p-xylylene glycol, dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid and isophthalic acid, trimellitic acid and pyromellitic acid. Polyfunctional dicarboxylic acid component,
Examples include oxycarboxylic acid components such as p-oxyethoxybenzoic acid.

When the dicarboxylic acid component is a dicarboxylic acid, after esterification reaction with glycol, and when it is a dicarboxylic acid ester, after transesterification reaction with glycol,
Polyester is obtained by polycondensation under high temperature and reduced pressure.

Further, the prepolymer itself may be used as a starting material for polycondensation.

The water-soluble polymer compound in the present invention means
There is no particular limitation as long as it is soluble in water. Specific examples include polyvinylpyrrolidone, polyvinyl alcohol, gelatin, partially alkylated cellulose, polyacrylic acid, polyacrylic acid ester, polyacrylic acid partial metal salt or partial ammonium salt, polymethacrylic acid,
Examples thereof include polymethacrylic acid esters and polyesters, which may be homopolymers or copolymers thereof. It is preferable that the dispersion stability when the water-soluble polymer compound is added to the water slurry of the cross-linked polymer particles is good, and the absolute value of the zeta potential in the region of pH 5 to 8 is particularly preferable. It is preferably larger than that before addition.

The molecular weight is 300 to 1000.
000 is preferable, and 1000 to 500,000 is more preferable. The water-soluble polymer compound in polyester is
For example, those which can be confirmed by dyeing with osmic acid, ruthenic acid, etc. are preferable, and it is particularly preferable that the particle surface is dyed. The treatment amount is 100 crosslinked polymer particles.
With respect to parts by weight, preferably 0.01 to 100 parts by weight,
More preferably, it is 0.1 to 30 parts by weight. The treatment of the crosslinked polymer particles with the water-soluble polymer compound is usually carried out in a solvent, but in consideration of blending with the polyester, it is preferably carried out in an aqueous system or a glycolyl system which is a structural unit of the polyester. The treatment method at this time may not be stirring but may be ultrasonic waves or the like, and a medium type mill such as a sand grinder may be used. In this case, one kind of water-soluble polymer compound may be used, or a plurality of compounds may be used.

The crosslinked polymer particles used in the present invention include:
Generally, a copolymer of a monovinyl compound (X) having only one aliphatic unsaturated bond in the molecule and a compound (Y) having two or more aliphatic unsaturated bonds in the molecule as a crosslinking agent, Alternatively, the latter may be composed of only the crosslinking agent (Y), but is not limited thereto.

Examples of the compound (X) include styrene and α
-Methylstyrene, fluorostyrene, vinylpyrine,
Aromatic monovinyl compounds such as ethylvinylbenzene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, butyl acrylate, 2-ethylhexyl acrylate, methyl acrylate, 2-hydroxyethyl acrylate, glycidyl acrylate, N, N'-
Acrylic acid ester monomers such as dimethylaminoethyl acrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, methacrylic acid ester monomers such as N, N′-dimethylaminoethyl methacrylate, acrylic acid, Methacrylic acid, maleic acid, acid anhydrides of mono- or dicarboxylic acids such as itaconic acid and dicarboxylic acids, acrylamide,
An amide-based monomer such as methacrylamide can be used. Examples of compound (Y) include divinylbenzene compound, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate, 1,3- Examples thereof include polyvalent acrylates and methacrylates such as butylene glycol dimethacrylate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate. Among the compounds (Y), it is preferable to use divinylbenzene, ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate in terms of controlling the particle size. In addition, these compounds (X),
(Y) may be used as a mixture of two or more kinds.

Preferred examples of the composition of the crosslinked polymer particles of the present invention include divinylbenzene copolymer (ethylvinylbenzene-divinylbenzene), butyl acrylate-divinylbenzene copolymer, 2-ethylhexyl acrylate-divinylbenzene copolymer. Examples thereof include crosslinked polymer particles such as a polymer and a 2-ethylhexyl acrylate-ethylene glycol dimethacrylate copolymer.
Further, butyl acrylate-ethyl vinylbenzene-divinylbenzene copolymer, styrene-ethylvinylbenzene-divinylbenzene copolymer, 2-ethylhexyl acrylate-ethylene glycol dimethacrylate-
The particles may be produced in a three-component system such as a divinylbenzene copolymer, or a multi-component system of more than three components.

Further, regarding the heat resistance of the crosslinked polymer particles of the present invention, particles having a heat resistance of 350 ° C. or more as the thermal decomposition temperature (10% weight loss temperature) by a thermobalance are preferable, more preferably 360 ° C. or more, particularly It is preferably 370 ° C. or higher. If the temperature is lower than 350 ° C., the particles tend to aggregate during melt molding during the production of the polyester composition or during the recovery and reuse of the molded product, so that the surface uniformity of the molded product and the abrasion resistance of the molded product tend to be excluded. In order to have such heat resistance, it is necessary to highly crosslink the compound (Y) with a crosslinking agent. The type of the cross-linking agent is not particularly limited, but divinylbenzene is preferable, and as divinylbenzene pure with respect to the monomer, preferably 5% by weight or more, more preferably 8%.
It is more than weight%. Further, the crosslinked polymer particles of the present invention may contain components other than the compounds (X) and (Y), and examples thereof include diethylbenzene which is an impurity of commercially available divinylbenzene.

The cross-linked polymer particles used in the present invention preferably have a spherical particle shape and a uniform particle size distribution in view of slipperiness, surface uniformity, transparency and the like. That is, it is preferable that the volume shape factor is 0.35 to 0.52, and further, it is 0.
It is preferably 45 or more. [However, the volume shape factor f is expressed by the following equation. f = V / D ³ , where V is the particle volume (μm ³ ), and D is the maximum diameter (μ of the particle on the projection plane).
m)]

As the crosslinked polymer particles of the present invention, those obtained by a known production method can be used. As a known production method, there is the following method, for example, by emulsion polymerization. (1) Soap-free polymerization method, that is, a method of using no emulsifier or using an extremely small amount of emulsifier. (2) A seed polymerization method in which polymer particles are added to the polymerization system prior to emulsion polymerization and emulsion polymerization is performed. (3) 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. (4) JP-A-54-97582 and JP-A-54
-126288, the polymerization method by Eugelstat et al. (5) A polymerization method which does not use a swelling aid in the method (4). Of the above methods, the methods (3) and (4) are particularly preferable because spherical crosslinked polymer particles having a uniform particle size distribution can be obtained.

In the present invention, the crosslinked polymer particles may have a functional group. The kind of such a functional group is not particularly limited, but examples thereof include a metal salt of a carboxyl group, a hydroxyl group, a sulfonic acid group, an ester group, and a carboxyl group.

The method of introducing the functional group is not particularly limited, but from the viewpoint of the heat resistance of the particle, it is preferable to once produce a particle which becomes a highly crosslinked matrix and introduce the functional group on the surface of the matrix particle. For example, when introducing a sodium salt of a carboxyl group, a styrene-divinylbenzene copolymer is used as a base particle to produce particles highly crosslinked with divinylbenzene, and then a carboxyl group is introduced onto the particle surface with methacrylic acid. . The functional group of -COONa is introduced on the surface of the particles by setting the inside of the particle production system to the alkaline side.

In the present invention, the average particle diameter of the crosslinked polymer particles dispersedly contained in the polyester is preferably in the range of 0.01 to 5 μm, more preferably 0, from the viewpoint of slipperiness, transparency and abrasion resistance. .05-2 μm.

The amount of the crosslinked polymer particles added to the polyester is preferably 0.0001 to 20% by weight, more preferably 0.001 to 10% by weight, and further preferably 0.01 to 5% by weight. Is.

In the present invention, the crosslinked polymer particles can be uniformly monodispersed in the polyester even if they are held by melting for a long time of 30 minutes or more. This uniform monodispersion means a state in which there are almost no secondary aggregated particles and the particles are dispersed as primary particles in the polymer. That is, when the polymer is observed with a transmission electron microscope, the number of secondary agglomerated particles per visual field of 0.01 mm ² is preferably 20 or less. More preferably 15
The number is less than or equal to 10, more preferably 10 or less.

The crosslinked polymer particles of the present invention can be contained in the polymer by various known methods such as a method of adding to and mixing with a polyester synthesis reaction system.
In a vent-type molding machine, water and / or an organic compound slurry having a boiling point of 200 ° C. or less of crosslinked polymer particles is added to polyester, and water and / or a boiling point of 200 are added under heating and reduced pressure.
The method obtained by removing an organic compound at a temperature of not higher than 0 ° C. and melt-kneading is preferable because it allows more uniform monodispersion. The vent-type molding machine is a melt molding machine having at least one vent hole, and may be, for example, an extrusion molding machine or an injection molding machine. At least one vent hole for removing water and / or an organic compound having a boiling point of 200 ° C. or less
First, it must be kept under reduced pressure. The degree of pressure reduction in the vent hole is preferably maintained at 100 Torr or less, more preferably 50 Torr or less, and further preferably 30 Torr or less.

On the other hand, the crosslinked polymer particles must be added to the polyester as water and / or an organic compound slurry having a boiling point of 200 ° C. or less. Examples of organic compounds having a boiling point of 200 ° C. or lower include methanol, ethanol,
Examples thereof include alcohols such as ethylene glycol, hydrocarbon compounds such as benzene and toluene, and esters, ketones, amines and the like, but are not particularly limited. Among them, water is preferable from the viewpoint of handling property, removability, and the like. Of course, the water and / or the organic compound may be a mixed solvent of two or more kinds, in which case a water-rich mixed solvent is preferable.

Further, in the slurry of crosslinked polymer particles,
From the viewpoint of particle dispersibility, it is preferable to include an anionic surfactant such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate.

Further, the concentration of the crosslinked polymer particles in water and / or the organic compound slurry having a boiling point of 200 ° C. or less is not particularly limited, but from the viewpoint of dispersibility in the polymer and the intrinsic viscosity of the polymer, 2% by weight or more and 30% by weight or less. Is preferred. It is more preferably 2% by weight or more and 20% by weight or less.

By using the method of the present invention, the polyester can contain a high concentration of crosslinked polymer particles. Therefore, it is also possible to produce a polyester containing a high concentration of crosslinked polymer particles, and dilute the polyester with substantially no particles before use.

According to this method, the crosslinked polymer particles can be added to and mixed with water in the state of water and / or an organic compound slurry having a boiling point of 200 ° C. or less. For example, when added during the polyester synthesis reaction,
Various adverse effects such as a significant delay in the polyester synthesis reaction due to water or a surfactant can be avoided and workability is improved. Further, even crosslinked polymer particles having relatively poor heat resistance can be mixed with polyester.

In the present invention, the cross-linked polymer particles in the polymer are uniformly monodispersed, so that when a stretched film is formed, a uniform uneven surface is obtained. Also, since there is no re-aggregation when melt-held, even in the film forming process,
It is possible to maintain a uniformly monodispersed state. Therefore, a film having slipperiness, transparency and abrasion resistance can be obtained.

Further, in the polyester of the present invention, a metal compound catalyst of compounds such as lithium, sodium, calcium, magnesium, manganese, zinc, antimony, germanium and titanium which are usually used in the production of polyester, and phosphorus as a coloring inhibitor. The compound may contain inactive particles other than the crosslinked polymer particles.

The film of the present invention can be used as a single layer film, of course, but a polyester composition containing crosslinked polymer particles and a polyester containing particles or substantially no particles are coextruded and laminated on at least one side. Later, when used in the form of a biaxially oriented film, the uniformity of the film surface, slipperiness, and wear resistance are improved, so
preferable.

The film thickness of the laminated part in the above is 0.1 to the average particle diameter of the crosslinked polymer particles added.
When it is 10 times, particularly 0.1 to 5 times, slipperiness and abrasion resistance are particularly good, which is preferable.

The content of the crosslinked polymer particles in the laminated portion in the present invention is 0.01 to 20% by weight, particularly 0.05 to 10%.
It is preferable that the content is wt% in terms of slipperiness and abrasion resistance. As a laminating method, a known laminating method such as melt co-extrusion can be appropriately used.

[0046]

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

(A) Particle size of particles The average particle size was measured by an electron micrograph of the particles,
It was determined by the particle equivalent spherical diameter corresponding to the point of 50% by volume.
The equivalent sphere diameter is the diameter of a sphere that has the same volume as the particle.

(B) Intrinsic Viscosity of Polymer Measured at 25 ° C. using o-chlorophenol as a solvent.

(C) Particle Thermal Decomposition Temperature Rigaku Denki TAS-100 under nitrogen atmosphere and temperature rising rate 2
The thermobalance weight loss curve at 0 ° C / min was measured. 10% was taken as the thermal decomposition temperature.

(D) Particle Dispersion State in Polymer After the polymer was cut into an ultrathin section of about 0.3 μm by an ultrathin film forming apparatus, the dispersion state of particles in the polymer was observed by a transmission electron microscope, and 0 The number of secondary agglomerated particles per field of view of 0.01 mm ² was counted.

(E) Dispersibility of Particles in Melting Polymer After holding the polymer at 290 ° C. for 30 minutes in N ₂ atmosphere,
It was solidified by cooling and analyzed by the method (D) described above.

(F) Film characteristics (1) Surface roughness Ra (μm) According to JIS-B-0601, it was measured using a stylus surface roughness meter (cutoff value 0.08 mm, measurement length 4 m).
m).

(2) Sliding property (μk) A tape running tester TBT-300 type (manufactured by Yokohama System Laboratory Co., Ltd.) was prepared by slitting a film into 1/2 inch.
Was run in an atmosphere of 20 ° C. and 60% RH, and the initial μk was calculated from the following formula. μk = 0.7331og (T ₁ / T ₂ ), where T ₂ is the inlet tension and T ₁ is the outlet tension. The guide diameter is 6 mmφ, the guide material is SUS27 (surface roughness 0.2S), the winding angle is 180 °, and the traveling speed is 3.3 cm / sec. When the above μk is 0.35 or less, the slipperiness is good. Here, μk is 0.35, which is a critical value of whether the slipperiness during film processing or as a product becomes extremely poor.

(3) Abrasion resistance Using a tape running tester TBT-300 (manufactured by Yokohama System Laboratory Co., Ltd.), after repeatedly running 2000 times in an atmosphere of 25 ° C. and 50% RH, the guide part The white shavings (white powder) adhering to is visually determined. Here, the guide diameter is 8 mmφ, the guide material is SUS27 (surface roughness 0.2S), the winding angle is 180 °, and the tape running speed is 3.3 cm / sec.

The evaluation criteria are as follows. ⊚: The amount of white powder generated is very small and the object is achieved. ◯: The amount of white powder generated is small and the purpose is achieved. Δ: The amount of white powder generated was rather large and the purpose was not achieved. X: The amount of white powder generated was very large, and the purpose was not achieved. The abbreviations, copolymerization amounts, addition amounts, and treatment amounts in the table are as follows. 1) SSIA: 5-sodium dimethyl sulfoisophthalate LSIA: 5-dimethyl sulfoisophthalate dimethyl DMI: dimethyl isophthalate 2) DVB-1: divinylbenzene copolymer particles (divinylbenzene 55%, ethylvinylbenzene 40%) DVB -2: divinylbenzene copolymer particles (divinylbenzene 70%, ethylvinylbenzene 25%) DVB-3: divinylbenzene copolymer particles (divinylbenzene 50%, ethylvinylbenzene 20%) BA: butyl acrylate 2EHA: 2 -Ethylhexyl acrylate 3) PVP: Polyvinylpyrrolidone P (VP / MA): Poly (vinylpyrrolidone / methyl acrylate) copolymer 4) Aromatic dicarboxylic acid or its ester-forming derivative (a) 100 parts by weight 5) Amount based on 100 parts by weight of the copolymerized aromatic polyester (A) 6) Amount based on 100 parts by weight of the crosslinked polymer particles (B)

Example 1 I.D. Synthesis of Copolymerized Aromatic Polyester (A) 100 parts by weight of dimethyl terephthalate, 1 part by weight of dimethyl 5-sodium sulfoisophthalate, and 70 parts by weight of ethylene glycol were charged into a flask with a rectification column and heated to 160 ° C.
After being melted in, and 0.06 parts by weight of magnesium acetate as a catalyst was added, the temperature was raised. While removing the methanol generated by the reaction from the rectification tower as the temperature rises, 240
The temperature was raised to ° C. After confirming that a predetermined amount of methanol was distilled, 0.03 part by weight of antimony trioxide and 0.03 part by weight of trimethyl phosphate were added, and polycondensation was carried out according to a usual method to obtain a copolymer having an intrinsic viscosity of 0.680. An aromatic polyester (A) was obtained.

II. Synthesis of polyethylene terephthalate composition (X) Divinylbenzene copolymer particles having an average particle size of 0.3 μm [commercially polymerized with 100% of commercially available divinylbenzene (55% divinylbenzene, 40% ethylvinylbenzene)]. Volume shape factor 0.51, thermal decomposition temperature 400 ° C.] 10 parts by weight, polyvinylpyrrolidone (molecular weight 10000) 0.1 parts by weight, water 90 parts by weight are mixed, and stirred with a turbine blade at room temperature for 1 hour, and the surface A water slurry of divinylbenzene copolymer particles (B) coated with polyvinylpyrrolidone was obtained. Next, using a vent type twin-screw extruder, the copolymerized aromatic polyester (A) is melted, and the divinylbenzene is added in an amount of 3.0 parts by weight based on 100 parts by weight of the polyester (A). Copolymer particle (B) water slurry was added. The ventro was held at a vacuum degree of 10 Torr and melt-extruded at a resin temperature of 280 ° C. to obtain a divinylbenzene copolymer particle-containing polyethylene terephthalate composition (X). The intrinsic viscosity of the obtained polymer is
It was 0.610. As a result of observing the polymer with a transmission electron microscope, the number of secondary agglomerations per field of 0.01 mm ² was 3, which was present in a substantially uniform monodisperse state.

Next, this polymer was treated at 290 ° C. under N ₂ atmosphere.
After holding for 30 minutes, the mixture was cooled and solidified, and the same evaluation was carried out. As a result, the number of secondary aggregations per field of 0.01 mm ² was 4
It was confirmed that the dispersion stability was maintained even when melted and stored.

III. Synthesis of polyethylene terephthalate (Y) 100 parts by weight of dimethyl terephthalate, 64 parts by weight of ethylene glycol as a catalyst, magnesium acetate 0.0
6 parts by weight was added to carry out a transesterification reaction. next,
Antimony trioxide (0.03 parts by weight) and trimethyl phosphate (0.03 parts by weight) were added to carry out a polycondensation reaction to obtain polyethylene terephthalate (Y) having an intrinsic viscosity of 0.620.

IV. Production of Laminated Polyester Film A polyethylene terephthalate composition (X) was melt-extruded at 290 ° C. onto a polynitylene terephthalate (Y) to obtain a laminated unstretched film. After that, it is stretched 3 times in each length and width at 90 ° C, and then at 220 ° C for 15 times.
Second heat treatment was performed to obtain a biaxially stretched film having a polyethylene terephthalate (Y) layer thickness of 8 μm and having a polyethylene terephthalate composition (X) layer thickness of 0.3 μm laminated thereon. When this film was evaluated, as shown in Table 1, it was a film having Ra = 0.014 μm, μk = 0.27, and very excellent abrasion resistance.

Examples 2 to 7 Copolymerization amount in copolymerized aromatic polyester (A), composition of crosslinked polymer particles in polyethylene terephthalate composition (X), average particle size, amount and type of surface treatment agent, A biaxially stretched film was obtained in the same manner as in Example 1, except that the lamination ratio of the film, the slurry addition method and the like were changed. The evaluation results of these films are shown in Tables 1 and 2, and the films were very excellent in particle dispersibility and abrasion resistance after remelting. Example 4
Then, the thickness of the laminated film was large and the abrasion resistance was slightly low. Although the film of Example 5 is a single film, μk was slightly high and abrasion resistance was slightly low. In Example 6, the content of particles in the laminated film was small, the μk was high, and the abrasion resistance was slightly lowered. In Example 7, although the divinylbenzene copolymer particles (B) water slurry coated with polyvinylpyrrolidone were added after the transesterification reaction during the production of the copolymerized aromatic polyester (A), the dispersibility before melting was Was deteriorated and a satisfactory film could not be obtained.

Comparative Example 1 V. Synthesis of polyethylene terephthalate composition (Z) Divinylbenzene copolymer particles having an average particle size of 0.3 μm [commercially polymerized with 100% of commercially available divinylbenzene (55% divinylbenzene, 40% ethylvinylbenzene)]. 10 parts by weight of a volume shape factor of 0.51 and a thermal decomposition temperature of 400 ° C.] and 90 parts by weight of water were mixed and stirred with a turbine blade at room temperature for 1 hour to obtain a divinylbenzene copolymer particle water slurry. Next, using a vent type twin-screw extruder, the polyethylene terephthalate (Y) is melted, and the divinylbenzene co-weight is adjusted so as to be 3.0 parts by weight with respect to 100 parts by weight of the polyester (Y). The coalesced particle water slurry was added. The vent port was maintained at a vacuum degree of 10 Torr, and melt extrusion was performed at a resin temperature of 280 ° C. to obtain a polyethylene terephthalate composition (Z) containing divinylbenzene copolymer particles. The intrinsic viscosity of the obtained polymer is 0.6.
It was 12. As a result of observing the polymer with a transmission electron microscope, the number of secondary agglomerations per field of 0.01 mm ² was 4, which was present in a substantially uniform monodisperse state.

Next, this polymer was treated at 290 ° C. under N ₂ atmosphere.
After 30 minutes of holding, the mixture was cooled and solidified, and the same evaluation was performed. As a result, the number of secondary agglomerations per 0.01 mm ² field of view was 44, and the dispersion stability could not be maintained due to melt storage. VI. Production of Laminated Polyester Film A polyethylene terephthalate composition (Z) was melt coextruded at 290 ° C. onto a polyethylene terephthalate (Y) to obtain a laminated unstretched film. After that, it is stretched 3 times in each length and width at 90 ° C, and then at 220 ° C for 15 times.
Second heat treatment was performed to obtain a biaxially stretched film having a polyethylene terephthalate (Y) layer thickness of 8 μm and having a polyethylene terephthalate composition (Z) layer thickness of 0.3 μm laminated thereon. When this film was evaluated, as shown in Table 3, it was a film having Ra = 0.16 μm, μk = 0.25, and poor abrasion resistance.

Comparative Examples 2 to 4 Copolymerization amount in aromatic polyester (A), composition of crosslinked polymer particles in polyethylene terephthalate compositions (X) and (Z), average particle size, surface treatment agent A biaxially stretched film was obtained in the same manner as in Comparative Example 1 except that the amount, type and the like were changed. The evaluation results of these films are shown in Table 3. Since these are outside the scope of the present invention, the films were inferior in particle dispersibility and abrasion resistance after remelting.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

Since the polyester composition of the present invention contains the specific polymer and the crosslinked polymer particles treated with the water-soluble polymer, it is in a uniform monodispersed state in the polymer and melted and held. Since the dispersion stability is maintained, the following excellent effects are further exhibited. For example, in the case of forming a film, the filter is not clogged due to agglomeration in the melt molding process, and the film is not broken due to agglomerated coarse particles. When the stretched film is used, a uniform uneven surface is obtained. Therefore, it is excellent in slipperiness, transparency, and abrasion resistance, and is suitable for magnetic tape applications, photographs, plate making applications, condenser applications and the like. When the composition of the present invention is used to form a laminated film, a large number of coarse protrusions due to agglomerated particles are obtained, and a film having good abrasion resistance can be obtained.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area B29L 9:00 4F

Claims (5)

[Claims] 1. An aromatic polyester (A) obtained by copolymerizing a compound having at least one sulfonic acid group or a metal sulfonate group, and a crosslink whose surface is partially or entirely treated with a water-soluble polymer compound. A polyester composition comprising polymer particles (B). 2. A vent type molding machine, wherein an aromatic polyester (a) having at least one sulfonic acid group or a metal sulfonate group is added to a crosslinked polymer particle (b-1) and a water-soluble polymer compound (b). 2) Water or boiling point 200
A method for producing a polyester composition, comprising adding a slurry (b) of an organic compound having a temperature of not higher than 0 ° C. 3. A biaxially oriented polyester film comprising the polyester composition of claim 1. 4. A biaxially oriented laminated film comprising the polyester composition according to claim 1 laminated on at least one surface. 5. The film thickness of the laminated portion according to claim 4, which is 0.1 to 10 times the average particle diameter of the crosslinked polymer particles (B),
The biaxially oriented laminated film, wherein the content of the particles is 0.01 to 20 parts by weight based on 100 parts by weight of the laminated part polymer.