JPH0872213A - Laminated film - Google Patents

Abstract

PURPOSE: To enhance antistatic properties and adhesiveness to a large extent by laminating a film with specific thickness based on a thermoplastic resin A and specific particles to the single surface of a film B based on a thermoplastic resin B and forming a C-layer composed of specific copolyester on the single surface of the laminated film. CONSTITUTION: A film A based on a thermoplastic resin A and particles is laminated to at least the single surface of a film B based on a thermoplastic resin B and the laminated film is processed into a biaxially oriented thermoplastic resin film. The thickness of the film A is set to 0.005-5μm and the average particle size of the particles contained in the film A is set to 0.1-10 times the thickness of the film A and the content of the particles in the film A is set to 0.1-50wt.%. A C-layer composed of copolyester containing 1-40wt.% of a polyoxyalkylene glycol component is lamainated to at least the single surface of the laminated constitution of the films A, B before or after the lateral stretching of sequential stretching or before simultaneous biaxial stretching.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminated polyester film. For details, antistatic property, slipperiness,
Excellent adhesion, blocking resistance, magnetic recording material,
The present invention relates to a laminated polyester film suitable as a base film used for various photographic materials, packaging materials, electrical insulating materials, general industrial materials, and the like. In particular, the present invention relates to a laminated film suitable as a base film used for magnetic recording materials.

[0002]

2. Description of the Related Art Polyesters, particularly polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate or poly-1,4-cyclohexanedimethylene terephthalate and polyesters containing these as main constituents are excellent. It has physical and chemical properties and is widely used as a fiber, film or sheet, and also as a molded product thereof.

In particular, since polyester films have excellent heat resistance, chemical resistance and mechanical properties, they are used in many applications such as magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials and general industrial materials. It is used.

In these applications, the polyester film is not used alone, and various coatings such as a magnetic paint, a chemical mat paint, a diazo photosensitive paint, a gelatin composition, and a heat seal are applied to the film surface. It is used by applying or printing a composition, ink, or the like.

In particular, films used for magnetic tapes, floppy disks, etc. are required to have flatness and smoothness for high reliability and high density of magnetic recording. There is a strong demand for improvement of the adhesive force with the base film. However, when the film is provided with an adhesive force to the magnetic coating material, conversely, blocking occurs between the films, which deteriorates various workability and deteriorates magnetic recording performance. On the other hand, in the process of manufacturing a magnetic tape or the like using a base film or an easy-adhesive film, in general, when passing through a process having many various rolls at a high speed, the gap between the roll and the film is Alternatively, the friction between the films causes an electrification phenomenon, which often necessitates a stop from the viewpoint of explosion proof, resulting in a decrease in workability and a deterioration in magnetic recording performance. Therefore, for imparting adhesiveness to the film, antistatic property of the film, slipperiness,
At the same time, it is necessary to satisfy the performance such as antiblocking property. At the same time, there is a demand for an easily-adhesive substance which is resistant to various solvents contained in various coatings applied or printed on the film surface.

However, since polyester itself is generally inactive and poor in adhesiveness, various coatings such as magnetic paints, chemical mat paints, diazo photosensitive paints, gelatin compositions, heat seal imparting compositions are formed on the film surface. Stuff,
When applying or printing ink, etc., physical treatment such as corona discharge or plasma or chemical treatment using alkali or amine chemicals is performed on the film surface to improve adhesion with the coating. Various methods are known, including a method of coating an easily adhesive substance and the like. However, the physical or chemical surface treatment method complicates the steps, not only increases the cost, but also fails to obtain sufficient adhesiveness.

On the other hand, the method of coating an easily adhesive substance can be carried out in the production process of the polyester film, is advantageous in terms of cost, and can select an adhesive substance which can be applied to various coatings. It is possible. Further, from the viewpoints of handleability of the polyester film and workability during film production, it has been proposed that various water-dispersed or water-soluble copolyesters and the laminating or coating of the copolyesters on the polyester film. For example, JP-A-50-83497 and JP-A-53-2
536 and JP-A-54-3848, polyesters obtained by copolymerizing an ester-forming sulfonic acid metal salt compound and an aliphatic dicarboxylic acid component, and further diethylene glycol, JP-A-59-215318. Examples of the film include a film undercoated with a polyester obtained by copolymerizing a metal salt compound capable of forming a sulfonic acid and an aliphatic dicarboxylic acid component.

As a biaxially oriented thermoplastic resin film with improved surface properties of the base film, polyester, which is a thermoplastic resin, contains substantially spherical silica particles derived from colloidal silica. Films are known (for example, JP-A-59-171623).

In such a biaxially oriented thermoplastic resin film, it is possible to improve the handling property and the running property by forming protrusions on the film surface by the contained silica particles and reducing the friction resistance of the surface. is there.

[0010]

However, the above-mentioned prior art has the following problems. That is, JP-A-50-83497 and JP-A-53-253
6, JP-A-54-3848 and JP-A-5-3848.
As in JP-A 9-215318, when an ester-forming sulfonic acid metal salt compound, an aliphatic dicarboxylic acid component, and further diethylene glycol are copolymerized, adhesiveness is exhibited, but blocking resistance and slipperiness are improved. Inferior,
There are drawbacks such that good antistatic properties cannot be obtained.

Further, in the biaxially oriented thermoplastic resin film disclosed in JP-A-59-171623, since the contained particles are randomly distributed over the entire thickness direction of the film, protrusions due to the contained particles on the film surface are formed. There is a limit to the increase in density, and the heights of the protrusions also vary considerably at random. Therefore, there is a limit in improving the film running property by reducing the frictional resistance, improving the scratch resistance of the film surface (hereinafter referred to as scratch resistance), and improving the abrasion resistance.

[0012]

The present invention solves these drawbacks and provides a biaxially oriented thermoplastic resin film in which a thermoplastic resin A and a thermoplastic resin B are laminated. By adopting a biaxially oriented thermoplastic resin film in which particles of a specific size are concentrated and contained to improve the film surface characteristics on the thermoplastic resin A side, the film surface is efficiently and densely formed, and It becomes possible to form protrusions having a uniform height, and the running property, scratch resistance, abrasion resistance, etc. can be significantly improved, and at the same time, the copolymerized polyester of the present invention is further laminated on at least one surface of the substrate. As a result, the antistatic property, the adhesive property, etc. can be significantly improved.

That is, an object of the present invention is to laminate a film A containing a thermoplastic resin A and particles as main components on at least one side of a film B containing a thermoplastic resin B as a main component, and to obtain a thickness A of the film. Of 0.005 to 5 μm, the film A
Biaxially oriented thermoplastic resin in which the average particle diameter of the particles contained therein is 0.1 to 10 times the thickness of the film A, and the content of the particles in the film A is 0.1 to 50% by weight. A laminated film having a polyoxyalkylene glycol component of 1% by weight or more on at least one side of the laminated film, 4
The main feature of the laminated film is a laminated film formed with a layer (C layer) composed of a copolymerized polyester containing less than 0% by weight.

The thermoplastic resin A in the present invention is not particularly limited to polyesters, polyolefins, polyamides, polyphenylene sulfides, etc., but especially polyesters, especially ethylene terephthalate, ethylene α,
When at least one structural unit selected from β-bis (2-chlorophenoxy) ethane-4,4, -dicarboxylate and ethylene-2,6-naphthalate units is a main constituent, It is preferable because the formation of the protrusions having a high density and a uniform height is further improved. Further, when the thermoplastic resin constituting the present invention is crystalline, the thermoplastic resin A
Is very desirable because it facilitates the formation of target projections on the layer surface. The term "crystallinity" as used herein means that it is not so-called amorphous. Quantitatively, the cold crystallization temperature Tcc in the crystallization parameter is detected, and the crystallization parameter ΔTcg is 150 ° C. It is as follows. Further, when the heat of fusion (change in enthalpy of fusion) measured by a differential scanning calorimeter shows a crystallinity of 7.5 cal / g or more, the thermoplastic resin A layer surface protrusion forming ability is excellent, which is extremely desirable. Further, a polyester containing ethylene terephthalate as a main constituent component is particularly preferable because the property of forming the surface protrusions of the thermoplastic resin A layer is further improved. Two or more kinds of thermoplastic resins may be mixed, or a copolymerized polymer may be used, as long as the present invention is not impaired.

The shape of the particles in the thermoplastic resin A of the present invention is not particularly limited, but particles having a particle size ratio (major axis / minor axis of particles) of 1.0 to 1.3 in the film, particularly, Spherical particles are preferable because they easily form film surface protrusions having a uniform height.

Further, when the particles in the thermoplastic resin A of the present invention have a single particle index in the film of 0.7 or more, preferably 0.9 or more, projections having a uniform height are formed at high density. It is particularly desirable because it is easy to do.

The type of particles in the thermoplastic resin A of the present invention is not particularly limited, but in order to satisfy the above preferable particle characteristics, alumina silicate, silica in which primary particles are agglomerated, internally precipitated particles and the like are used. Not preferable. Preferable particles include substantially spherical silica particles derived from colloidal silica and particles formed by a cross-linked polymer (for example, cross-linked polystyrene). Particularly, the temperature at 10% by weight reduction (thermogravimetric analyzer in nitrogen, Shimadzu TG- Measured using 30 M. It is particularly desirable in the case of cross-linked polymer particles in which the degree of cross-linking is increased until the temperature rising rate is 20 ° C./min) to 380 ° C. or higher, because the film surface protrusion forming property is further improved. In the case of spherical silica derived from colloidal silica, substantially spherical silica produced by the alkoxide method and having a low sodium content is desirable. However, other particles such as calcium carbonate, titanium dioxide, and alumina can be sufficiently used by controlling the film thickness and the average particle size appropriately.

The thickness of the film layer containing the thermoplastic resin A as a main component of the present invention is 0.005 to 5 μm, preferably 0.01 to 1
It is necessary that the thickness is μm, more preferably 0.03 to 0.5 μm. If the film thickness is smaller than the above range, the durability as a laminated film layer cannot be ensured, and conversely if the film thickness is large, it becomes difficult to form surface protrusions with an appropriate height at high density due to the relationship with the contained particles. Become.

The size of the particles contained in the film of the thermoplastic resin A is such that the average particle diameter in the laminated film containing the particles is 0.1 to 10 times, preferably 0.5 to 10 times the thickness of the laminated film. The range is 5 times, more preferably 1.1 to 3 times. When the average particle diameter / film thickness ratio is smaller than the above range, the variations in the film surface protrusions formed become large, resulting in poor scratch resistance and abrasion resistance improving effects. Is not preferable, and the particle concentration ratio on the film surface to be described later is likely to be lowered, and the scratch resistance and abrasion resistance improving effects are also unfavorably deteriorated.

The average particle size (diameter) of the particles in the thermoplastic resin A in the film is 0.005 to 3 μm, preferably
When the thickness is in the range of 0.02 to 0.45 μm, the effect of improving scratch resistance and abrasion resistance of the film surface is further improved, which is desirable.

Then, such particles are contained in the film of the thermoplastic resin A in an amount of 0.1 to 50% by weight. If it is smaller than this, the film surface protrusion formation density becomes too low, and thus good unevenness transfer characteristics to the magnetic surface cannot be obtained. Conversely, if it is too high, the proportion of the content particles becomes too high, and the laminated film layer itself becomes brittle. It is not preferable because it becomes too much.

Further, the average height of the surface protrusions of the laminated film layer of the thermoplastic resin A formed by the above particles is
It is 1 / 3.5 or more of the average particle size of the particles. The surface protrusion having such an average height can be obtained by appropriately selecting and setting the average particle diameter of the contained particles with respect to the thickness of the laminated film from the above range.

That is, the laminated film layer of the thermoplastic resin A in the present invention contains particles having an average particle diameter in the vicinity of the film thickness or larger. In other words, the ultrathin laminated film contains fine particles having an average particle diameter in the vicinity of the film thickness or larger than that.
Therefore, the particles can be distributed in the thickness direction of the entire biaxially oriented thermoplastic resin film, substantially concentrating only on the laminated film layer. As a result, the density of particles that can be placed in the laminated film can be easily increased, and the density of protrusions on the film surface formed by the particles can also be easily increased. Further, the particles, by being contained in the laminated film, relative to the entire biaxially oriented thermoplastic resin film, the position will be regulated in the thickness direction, moreover, the thickness and the average particle diameter of the laminated film Has the above-described relationship, the height of the surface protrusions formed by the particles is extremely uniform. By forming surface protrusions with high density and uniform height, scratch resistance and abrasion resistance of the film surface are significantly improved.

The film containing the thermoplastic resin A and particles as the main components is laminated on the film containing the thermoplastic resin B as the main component.

The thermoplastic resin B is the above-mentioned thermoplastic resin A.
The thermoplastic resin B and the thermoplastic resin A may be of the same type or of different types. The film layer of the thermoplastic resin A is laminated on both sides or one side of the film layer made of the thermoplastic resin B. That is, this is the case where the laminated structure is A / B / A or A / B. (here,
The types of the thermoplastic resins of A and B may be the same or different. Further, at least one surface needs to be the A layer. ) Also as the thermoplastic resin B, a crystalline polymer is desirable, and particularly, a crystalline parameter ΔTcg is preferable.
When the temperature is in the range of 20 to 100 ° C., the durability of the whole base film as a magnetic recording medium is further improved, which is desirable. Specific examples thereof include polyester, polyamide, polyphenylene sulfide, and polyolefin. In the case of polyester, the durability of the film as a whole is further improved, which is particularly desirable. Also,
As the polyester, ethylene terephthalate, ethylene α, β-bis (2-chlorophenoxy) ethane-4,
A film containing at least one structural unit selected from 4, -dicarboxylate and ethylene 2,6-naphthalate units as a main constituent is preferable as a film for a magnetic recording medium. However, other components may be copolymerized within a range that does not impair the present invention and a range that does not impair the desired crystallinity, and preferably within 5 mol%.

Further, the thermoplastic resin B of the present invention may be blended with another type of polymer within a range not impairing the object of the present invention, and may be an antioxidant, a heat stabilizer, a lubricant, or an ultraviolet absorber. Organic additives such as agents may be added to the extent that they are usually added.

It is not necessary for the film containing the thermoplastic resin B as a main component to contain particles, but when this film forms one side of the film surface, the average particle size is 0.
007 to 2 μm, especially 0.02 to 0.45 μm particles are 0.001 to 0.2
% By weight, especially 0.005-0.15% by weight, and even 0.005
When it is contained in an amount of 0.12% by weight, not only the friction coefficient and scratch resistance are improved, but also the winding shape of the film is improved, which is very desirable, for example, in the use as a base film for magnetic recording media. As the type of particles contained, it is desirable to use those which are preferably used in the thermoplastic resin A. The types and sizes of particles contained in the thermoplastic resins A and B may be the same or different.

Thermoplastic resin A containing particles as described above
And thermoplastic resin B are laminated by coextrusion, molded into a sheet, and then biaxially stretched to obtain a biaxially oriented thermoplastic resin film. Laminating by coextrusion in the present invention means extruding a thermoplastic resin A containing particles and a thermoplastic resin B by different extruders, and laminating these before discharging a laminating sheet from a die. Say. This lamination may be performed in a die for molding and discharging in a sheet shape (for example, a manifold), but since the laminated film layer is extremely thin as described above, it is in the polymer pipe before being introduced into the die. It is preferable to carry out. In particular, it is particularly preferable that the laminated portion in the polymer tube is formed in a rectangular shape because the laminated portion can be uniformly laminated in the width direction. The molten polymer laminated at the rectangular laminated portion in the polymer pipe is widened to a predetermined width in the sheet width direction by the manifold in the die, discharged in a sheet shape from the die, and then biaxially stretched. Therefore, even if the laminated film after the biaxial orientation is extremely thin, the particle-containing thermoplastic polymer is laminated in a considerable thickness in the rectangular laminated portion in the polymer tube, so that it can be laminated easily and accurately. it can.

In the biaxially oriented thermoplastic resin film composed of the thermoplastic resin A and the thermoplastic resin B, the particle concentration ratio of particles in the surface layer on the laminated film side containing particles is 0.1 or less. Is preferred. This surface layer particle concentration ratio shows how the particles forming the film surface protrusions are covered with the thin film of the thermoplastic resin A on the film surface, as shown in the measuring method described later. The higher the degree of substantially direct exposure, the higher the surface layer particle concentration ratio, and the higher the degree that the surface projections are formed but covered with the thin film of the thermoplastic resin A, the lower the surface layer particle concentration ratio. Since the particles forming the protrusions are covered with the thin film of the thermoplastic resin A, even if the particles are densely distributed in the ultrathin laminated film layer,
The particles will be held firmly in the laminated film layer, and thus in the base film layer of the thermoplastic resin B.
Therefore, by setting the surface layer particle concentration ratio to the above value or less, the particles are prevented from falling off, and the durability of the film surface is maintained high. Such a surface layer particle concentration ratio can be achieved by performing lamination by coextrusion.

By the way, depending on the coating method,
It is possible to coat a resin layer having a very thin thickness with respect to a film similar to that of the present invention, that is, a base film layer, and to contain particles in the resin layer, but the surface layer particle concentration ratio is remarkably high. It becomes high (that is, the degree of direct exposure of the particles to the surface is substantially high), and only the surface of the film of the present invention is extremely brittle.

Then, the polyoxyalkylene glycol component is contained in the film having the laminated structure of the film layer of the thermoplastic resin A and the film layer of the thermoplastic resin B as described above in an amount of 1% by weight or more and less than 40% by weight. The layer C of the copolyester contained is laminated to complete the laminated film of the present invention.

The laminated structure is A / B / C, A / B /
Either A / C or C / A / B / A / C may be used, but A / B / C is particularly preferable. When the film of the present invention is used as a magnetic recording medium, the magnetic layer is preferably provided on the C layer side.

The layer C can be laminated in each step in the biaxially oriented thermoplastic resin film manufacturing process.
Since the layer is an extremely thin layer, it is rolled on the surface of the C layer before the C layer or the whole film is molded and fixed after the C layer is laminated.
It is preferable that no contact is made between them. Therefore, for example, the C layer is preferably laminated before or after the widthwise stretching in the sequential biaxial stretching in which the longitudinal stretching and then the widthwise stretching are performed, or before the simultaneous biaxial stretching. The lamination is industrially preferable such as so-called in-line coating in which coating is performed during the continuous film production process, but it may be performed in another dedicated process offline.

As the C layer, by laminating a layer made of a copolyester containing the polyoxyalkylene glycol component of the present invention in an amount of 1% by weight or more and less than 40% by weight, a synergistic effect with a base film is obtained. Has excellent antistatic properties, smoothness and smoothness, abrasion resistance, solvent resistance, etc., as well as adhesion to the magnetic layer when used in magnetic recording media, electromagnetic characteristics, durability of the magnetic surface, etc. It can be further improved. The copolymerized polyester in the present invention is not particularly limited as long as it is a copolymerized polyester containing a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 40% by weight, and the characteristics of the obtained layer and From the viewpoint of handleability, a water-soluble or water-dispersible copolyester is preferable, and a water-soluble copolyester is particularly preferable.

The acid component of the copolyester is preferably 60 mol% or more, more preferably 70 mol% or more, and particularly preferably 80 mol% or more, as an acid component of the aromatic dicarboxylic acid. It is preferable because it is excellent in prevention property and solvent resistance. 60 aromatic dicarboxylic acids
If it is less than mol%, the antistatic property, antiblocking property and solvent resistance are poor. The aromatic dicarboxylic acid is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, diphenyl ether dicarboxylic acid and the like. Among these, preferred aromatic dicarboxylic acids are terephthalic acid and isophthalic acid. Acid, naphthalenedicarboxylic acid.

From the viewpoint of imparting water solubility, the copolymerized polyester of the present invention contains the ester-forming alkali metal sulfonate compound in an amount of 5 to 40 mol%, preferably 7 to 30 mol%, and more preferably 10 to 30 mol%. Is 10 to 20 mol%,
It is particularly preferable to add 11 to 15 mol%. If the amount of the ester-forming alkali metal sulfonate compound is less than 5 mol%, sufficient water solubility and adhesiveness cannot be obtained. On the other hand, when it exceeds 40 mol%, the adhesiveness reaches saturation, and conversely, the antistatic property, antiblocking property and solvent resistance decrease. The ester-forming sulfonic acid alkali metal salt compound is not particularly limited, and examples thereof include sulfoterephthalic acid, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, 4-sulfonaphthalene-2, Examples thereof include alkali metal salts such as 6-dicarboxylic acid, and among them, lithium, sodium and potassium salts of 5-sulfoisophthalic acid and sulfoterephthalic acid are more preferably used.

The glycol component of the copolyester of the present invention comprises an aliphatic glycol having 2 to 8 carbon atoms and / or 80 to 99 mol% of an aliphatic cyclic glycol having 6 to 16 carbon atoms, ethylene glycol. -Olegomer 1 to 20 mol%, preferably C 2 to C 8 aliphatic glycol and / or C 6 to C 16 alicyclic glycol 82 to 95 mol%, ethylene glycol oligomer 3 to 18 mol%, and more preferably an aliphatic glycol having 2 to 8 carbon atoms and / or an alicyclic glycol 84 having 6 to 16 carbon atoms.
~ 93 mol%, ethylene glycol oligomer 6-15
Mol%.

Aliphatic glycol having 2 to 8 carbon atoms and /
Or 80 mol% of alicyclic glycol having 6 to 16 carbon atoms
If the amount is less than 20% or the ethylene glycol oligomer exceeds 20% by mole, other properties such as blocking resistance, slipperiness and solvent resistance are significantly deteriorated, which is not preferable.
On the other hand, when the aliphatic glycol having 2 to 8 carbon atoms and / or the aliphatic cyclic glycol having 6 to 16 carbon atoms exceeds 99 mol%, or the ethylene glycol oligomer is less than 1 mol%, Although blocking resistance is good,
Poor water solubility and adhesiveness.

Examples of the C2-C8 aliphatic glycol and / or C6-C16 alicyclic glycol of the present invention include ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2 -Cyclohexane dimethanol, 1,3
There may be mentioned glycols such as cyclohexane dimethanol and 1,4-cyclohexane dimethanol.
Preferred aliphatic glycols having 2 to 8 carbon atoms and / or alicyclic glycols having 6 to 16 carbon atoms include ethylene glycol, neopentyl glycol, 1,4-butanediol and 1 , 4-cyclohexane dimethanol. These glycols may be used alone or in combination of two or more.

The ethylene glycol oligomer referred to in the present invention is a low polymer of ethylene glycol represented by the following formula (2), preferably n = 2-5, particularly preferably n = 2 ( Diethylene glycol). These ethylene glycol oligomers may be used alone or in combination of two or more.

HO (CH ₂ CH ₂ O) _n H (2) (where n = 2 to 8) The ethylene glycol oligomer such as diethylene glycol in the present invention is usually produced by the production of polyester containing ethylene glycol as a glycol component. It contains an ethylene glycol oligomer such as diethylene glycol which is by-produced.

In the water-soluble copolyester of the present invention, in addition to the above-mentioned acid component and glycol component, an aliphatic dicarboxylic acid, an oxy acid or a monofunctional compound, and a trifunctional or higher functional compound are used as long as the effects of the present invention are not impaired. It may also contain other components such as polyfunctional compounds. The content of these other ingredients is
It is not particularly limited as long as it does not impair the effects of the present invention, but is usually about 30 mol% or less.

The copolymerized polyester of the present invention can be produced by any conventionally known method and is not particularly limited. For example, terephthalic acid as the acid component, 5
Explaining a copolyester composed of sodium sulfoisophthalic acid and ethylene glycol or diethylene glycol as a glycol component, terephthalic acid, 5-sodium sulfoisophthalic acid and ethylene glycol or diethylene glycol are directly esterified. Reaction or alkyl ester of terephthalic acid, 5
A method of producing by a first step in which an alkyl ester of sodium sulfoisophthalic acid and ethylene glycol, diethylene glycol are transesterified, and a second step in which the reaction product of this first step is subjected to a polycondensation reaction, etc. Can be mentioned. At this time, as a reaction catalyst,
Conventionally known alkali metals, alkaline earth metals, manganese, cobalt, zinc, antimony, germanium, titanium compounds and the like are included, and phosphorus compounds and the like may be used as a coloring preventing agent.

The copolyester of the present invention contains the polyoxyalkylene glycol component in an amount of 1% by weight or more and 40% or more.
It should be contained in an amount of less than 10% by weight, preferably 10 to 30% by weight, particularly preferably 15 to 20% by weight. Generally, a water-soluble copolyester has an ester-forming sulfonic acid alkali metal salt compound as a copolymerization component in order to impart water solubility. However, since the sulfonic acid group promotes negative electrification in triboelectrification, the copolyester The easy-adhesive polyester film laminated with
It shows a strong negative charge in the usual peeling charge and in the process charge using a lot of silicon rolls. As a result of earnest research in the present invention, a method of avoiding this negative charging and introducing a polyether chain on the positive side of the polyethylene terephthalate in the charging train so as to be plus or minus zero in the process charging is adopted. As a result of various studies, it has been found that polyoxyalkylene glycol can be positively charged by frictional charging and process charging, and its content is preferably 1% by weight or more and less than 40% by weight.

The relationship between the content of the polyoxyalkylene glycol component and the triboelectric charge has a maximum value, and if it is less than 1% by weight, sufficient antistatic property cannot be obtained. On the other hand, when the content of the polyoxyalkylene glycol component is 40% by weight or more, on the contrary, the antistatic property becomes poor and the slipperiness and the blocking resistance also become poor, which is not preferable.
The type of the polyoxyalkylene glycol component is not particularly limited, but the number average molecular weight of the polyoxyalkylene glycol component is 400 to 10,000 from the viewpoint of combining excellent adhesiveness, water solubility, and antistatic property. The number average molecular weight is preferably 500 to 6000, more preferably the number average molecular weight is 600 to 4000. Examples of such polyoxyalkylene glycol components include polyethylene glycol, polypropylene glycol,
Examples thereof include polytetramethylene glycol. Among them, polyethylene glycol is preferable from the viewpoint of water solubility, antistatic property and adhesiveness.

In the present invention, the polyoxyalkylene glycol content [A wt%] and the ethylene glycol oligomer content [B mol%] of the water-soluble copolyester are 1≤A / B≤10, preferably Is 2 ≦ A / B ≦ 7,
It is more preferable to satisfy the relation of 3 ≦ A / B ≦ 5. Further, the content of ethylene glycol oligomer is preferably 1 mol% or more and less than 20 mol%.
When A / B is less than 1, the antistatic property tends to deteriorate, and when A / B is 10 or more, the water solubility tends to deteriorate. Also, ethylene glycol
If the oligomer content is less than 1 mol%, the adhesiveness and water solubility tend to be poor, and if it is 20 mol% or more, the antistatic property, blocking resistance, slipperiness, etc. tend to be poor.

Generally, if the content of polyoxyalkylene glycol is increased for positive charging, the water solubility decreases. Therefore, as a result of earnest research on the antistatic property of the easy-adhesion film in the process charging, the ethylene glycol oligomer content in the water-soluble copolyester is closely related to the solubility, and the ethylene glycol oligomer content is It was found that the larger the amount, the higher the solubility. That is, the polyoxyalkylene glycol-containing copolyester is generally difficult to be solubilized due to the crystallinity of the polyoxyalkylene glycol, but by increasing the amount of the ethylene glycol oligomer, the amorphous effect is obtained. It is speculated that the solubility can be improved. Therefore, the amount of polyoxyalkylene glycol can be increased, and the charging characteristics can be improved.

The method of incorporating the polyoxyalkylene glycol component of the present invention into the copolyester is not particularly limited. For example, the polyoxyalkylene glycol component may be added at any stage of the process for producing the copolyester. Examples thereof include a method of adding and a method of melt-kneading the copolyester and the polyoxyalkylene glycol component using an extruder or the like. On this occasion,
The polyoxyalkylene glycol component can be added by any method such as powder, melting or solution state.

The intrinsic viscosity of the water-soluble copolyester of the present invention is not particularly limited, but it is preferably 0.3 dl / g or more from the viewpoint of adhesiveness, and further 0.4 d.
It is preferably 1 / g or more.

If necessary, the water-soluble copolyester may contain a flame retardant, a heat stabilizer, an ultraviolet absorber, a pigment,
Dyes, fatty acid esters, organic lubricants such as waxes or antifoaming agents such as polysiloxy acid may be blended, and clay, mica, titanium oxide, calcium carbonate, kaolin, wet type and wet type for the purpose of imparting lubricity. Inorganic particles such as dry-process silica, colloidal silica, calcium phosphate, barium sulfate, and alumina, as well as organic particles containing acrylic acid, styrene, or the like as a constituent component may be blended.

The copolyester to be laminated on the film of the present invention is preferably dissolved in water and used as an aqueous solution. This aqueous solution does not have rigor in terms of physical and chemical senses, but also includes an aqueous solution that is mostly dissolved in water and partially dispersed.

The oxidized wax in the present invention is not particularly limited, but for example, a carboxyl group-containing hydrocarbon wax oxidized with oxygen, an oxidized polyethylene wax obtained by oxidizing polyethylene wax with oxygen, or a mixture thereof. And partially oxidized wax. The molecular weight and melting point are not particularly limited, but those having a molecular weight of 1000 or more are preferable.

As the natural wax, candelilla wax, carnauba wax, wooden wax, oricure wax.
Examples thereof include re-wax and sugar cane wax, and carnauba wax is particularly preferable in the present invention.

The oxidized wax and the natural wax in the present invention may be used alone or in combination with the copolymerized polyester. Furthermore, a rosin-modified wax may be further mixed with the oxidized wax and / or the natural wax. The rosin-modified wax is not particularly limited, but in the present invention, a composition comprising the following compounds is particularly preferable. That is, {rosin or disproportionated rosin, or hydrogenated rosin / α, β-substituted ethylene (α-substituent: carboxyl, β-substituent: hydrogen or methyl or carboxyl) adduct} ・ alkyl or alkenyl (each having 1 carbon atom)
~ 8) It is particularly preferable to use an ester adduct of poly (repeating unit: 1-6) alcohol. The mixing ratio of the oxidized wax and / or the natural wax (A) and the rosin-modified wax (B) is not particularly limited,
(A) / (B) is 10/90 to 90/10, preferably 20/80 to 80/20, more preferably 30/70 to
It is preferably 70/30. Mixing ratio (A) /
The reason that (B) is 90/10 or less is that it is suitable for obtaining a uniform coating film having good uniform dispersibility when emulsified or suspended in water. The reason for setting it to 10/90 or more is that the slipperiness after coating is good.

Although the slipperiness imparting effect and blocking preventing effect of the oxidized wax or natural wax of the present invention have not been fully clarified, the wax of the present invention has a dispersive component of surface free energy as compared with paraffin wax. It is presumed that the same effect is exhibited in the mixed system with the copolyester because it is large and the polar component is small.

Various additives may be used in combination in the above composition within a range that does not impair the effects of the present invention. Examples thereof include antistatic agents, heat-resistant agents, antioxidants, organic and inorganic particles, pigments and the like.

The layer to be laminated on the base film in the present invention is a layer mainly composed of the above-mentioned copolymerized polyester and the above-mentioned oxidized wax or natural wax or a mixture thereof. is there.
The term "copolymerized polyester and wax as a main component" means that the mixture is 80% by weight or more, preferably 90% by weight of the coating film.
It is desirable that the content is at least wt%.

In the present invention, 70 to 99.9% by weight, preferably 85 to 9% by weight of copolymerized polyester is contained in the layer.
It is necessary to mix 9% by weight and 30 to 0.1% by weight of wax, preferably 15 to 1% by weight. When the content of the copolyester is 70% by weight or less, the adhesion becomes poor, which is not preferable. On the other hand, if it is 99.9% by weight or more, slipperiness and blocking resistance tend to be poor, which is not preferable. Within the scope of the present invention, antistatic properties, slipperiness,
It is preferable in terms of achieving both adhesiveness and blocking resistance.
A known crosslinking agent such as a silane coupling agent may be added to the layer as another component. The thickness of the layer is not particularly limited, but it is 0.001 to 1 μm, and particularly 0.1.
01 to 0.2 μm is preferable.

Next, the method for producing the film of the present invention will be described.

First, as a method of incorporating particles into the thermoplastic resin A, either after polymerization, during polymerization or before polymerization may be used, but a method of kneading the polymer with a vent type twin-screw extruder is used. It is effective for obtaining a film having a surface morphology within the scope of the invention. In addition, as a method for adjusting the content of particles, a high-concentration master is prepared by the above method, and the content of particles is adjusted by diluting it with a thermoplastic resin that does not substantially contain particles during film formation. The method is effective to obtain a surface morphological film within the scope of the present invention. Further, the method of adjusting the melt viscosity, copolymerization component and the like of the high concentration master polymer of particles to keep the crystallization parameter ΔTcg in the range of 30 to 80 ° C. causes less stretching breakage and has a surface morphology within the range of the present invention. It is effective in obtaining a film.

Thus, after the pellets A containing the particles are sufficiently dried, they are fed to a known melt extruder, extruded in a sheet form from a slit die, cooled and solidified on a casting roll and unstretched. Make a film. That is,
These thermoplastic resins are laminated using two or three extruders, a merging block or a die for two or three layers. When the confluent block method is used, the laminated portion should be rectangular as described above, and the difference (absolute value) in viscosity between the two thermoplastic resins should be in the range of 0 to 2000 poise, preferably 0 to 1000 poise. It is effective for industrially producing a film having a surface morphology within the scope of the present invention stably and without unevenness in the width direction.

Next, the multilayer unstretched film is biaxially stretched to be biaxially oriented. The method of biaxial stretching may be either simultaneous biaxial stretching or sequential biaxial stretching, but in the case of sequential biaxial stretching in which the longitudinal direction and the width direction are sequentially stretched, a film having a surface morphology within the scope of the present invention is stabilized. Therefore, it is effective for industrial production without unevenness in the width direction. In the case of sequential biaxial stretching,
Stretching in the longitudinal direction is divided into 3 stages, particularly 4 stages or more,
The method of performing 3 to 6 times in the range of 40 to 150 ° C. and the stretching rate of 1000 to 5000% / min is effective for obtaining a film having a surface morphology within the range of the present invention. Stretching temperature in the width direction,
The speed is preferably 80 to 170 ° C. and 1000 to 20000% / min. The stretching ratio is preferably 3 to 10 times. Further, if necessary, it can be further stretched in at least one of the longitudinal direction and the width direction. It is also possible to use a method in which an extremely thin layer containing particles is provided as needed, and then stretching is performed at an area stretching ratio (longitudinal direction ratio x width direction ratio) of 9 times or more. Next, this stretched film is heat-treated. In this case, the heat treatment condition is 140 to 280 ° C., preferably 0.5 to 60 seconds in the range of 140 to 280 ° C., preferably 160 to 260 ° C., in any state of relaxation in the width direction, fine stretching, and under constant length. It is preferable to use microwave heating in combination with the heat treatment because a film having the surface morphology of the present invention can be easily obtained.

The layer C in the present invention is most preferably laminated by coating during the film manufacturing process and stretching together with the substrate. For example, the melt-extruded film before crystal orientation is stretched in the longitudinal direction by about 2.5 to 5 times, the surface to be continuously coated is subjected to corona discharge treatment, and the coating liquid is applied to the treated surface. The applied film is dried while passing through a zone that is heated stepwise, and the width of the film is 2.5 to 5
It is stretched about twice. Further, it is obtained by a method of continuously introducing a heating zone of 150 to 250 ° C. to complete the crystal orientation. The coating liquid used in this case is preferably an aqueous system from the viewpoint of environmental pollution and explosion proof. As the method of coating on the substrate film, a known coating method such as a reverse coat method, a gravure coat method, a rod coat method, a die coat method, and a wire bar method can be used. . In the coating layer (easy adhesion layer), known additives such as a heat resistance stabilizer, an oxidation resistance stabilizer, and a weather resistance stabilizer within a range that does not impair the effects of the present invention,
An ultraviolet absorber, an organic lubricant, a pigment, a dye, organic or inorganic fine particles, a filler, an antistatic agent, a nucleating agent and the like may be added. As the coating composition, the water-soluble copolyester is 0.5 parts by weight of the water-soluble copolyester.
Those containing about 10 to 10% by weight are preferable. The water-soluble copolyester paint can be prepared, for example, by adding the water-soluble copolyester to hot water at about 60 to 80 ° C and stirring. The wax paint preferably contains a wax component in water in an amount of about 1 to 30% by weight. It is preferable to add, for example, about 1% by weight of a nonionic surfactant, a phosphoric acid ester, ammonium oleate, 2-amino-2-methylpropanol, etc., because the wax can be easily dispersed in water. It is preferable that the water-soluble copolyester paint and the wax paint are mixed and then applied to a polyester film. In the above example, the polyester substrate to which the copolyester is applied also contains a polymer in which a compound having a sulfonic acid and / or a salt thereof is copolymerized, polyethylene glycol, and an oxidized wax and / or a natural wax. be able to. In this case, there are advantages such as improvement in slipperiness, blocking resistance, and adhesion between the coating layer and the base film. When a composition containing a polymer in which a compound having a sulfonic acid and / or a salt thereof is copolymerized, polyethylene glycol and an oxide wax and / or a natural wax is contained, the addition amount is 5 p
It is preferable that the content is pm or more and less than 20% by weight from the viewpoints of slipperiness, blocking resistance and adhesion improvement. Needless to say, it may be a coating composition provided on the base film (including recycled pellets of the laminated film of the present invention).

The winding property of the laminated film thus obtained,
The slitting property is good, and by applying a coating agent according to the application to the coating layer side, various applications such as magnetic recording materials, cellophane inks, offset inks, UV curable inks, various ink printing, electronic It is preferably used as a base film for photographic toner, easy adhesion, chemical mat paint easy adhesion, diazo paint easy adhesion, and inorganic coating such as vapor deposition.

[0065]

[Characteristic value measuring method and evaluation method] The characteristic measuring method and the effect evaluating method in the present invention are as follows.

(1) Average Particle Size of Particles The thermoplastic resin is removed from the film by a plasma low temperature ashing method (for example, PR-503 type manufactured by Yamato Scientific Co., Ltd.) to expose the particles. The treatment conditions are selected such that the thermoplastic resin is incinerated but the particles are not damaged. This is SEM
Observe with a (scanning electron microscope), connect the image of the particles (light and shade of light generated by the particles) to an image analyzer (for example, QTM900 manufactured by Cambridge Instruments), and change the observation point to The average particle diameter is obtained by performing the numerical treatment of.

D = ΣDi / N Here, Di is the equivalent circle diameter of particles, and N is the number.

(2) Content of particles A solvent which dissolves the thermoplastic resin and does not dissolve the particles is selected, and the particles are centrifuged from the thermoplastic resin. To do.
In some cases, combined use of infrared spectroscopy is also useful.

(3) Glass transition point Tg, cold crystallization temperature T
cc, crystallization parameter ΔTcg, melting point Perkin Elmer DSC (differential scanning calorimeter) type. The measurement conditions of DSC are as follows. That is, 10 mg of the sample was set in a DSC device and
After melting for 5 minutes at a temperature of ° C, it is quenched in liquid nitrogen.
The temperature of this quenched sample is raised at 10 ° C./min, and the glass transition point Tg is detected. The temperature was further raised, and the crystallization exothermic peak temperature from the glass state was set as the cold crystallization temperature Tcc.
The temperature was further raised and the melting peak temperature was taken as the melting point. Also,
The difference between Tcc and Tg (Tcc-Tg) is defined as the crystallization parameter ΔTcg.

(4) Average height of surface protrusions The film surface was measured by a scanning electron microscope [ESM-3200, manufactured by Elionix Co., Ltd.] using a two-detector method and a cross-section measuring device [PMS-1, manufactured by Elionix Co., Ltd.]. The height measurement value of the projection when scanning is performed with the height of the flat surface of 0 is sent to the image processing apparatus [IBAS2000, manufactured by Karzeiss Co., Ltd.] to reconstruct the film surface projection image on the image processing apparatus. . Next, a circle equivalent diameter is obtained from the area of each protrusion obtained by binarizing the protrusion portion in this surface protrusion image, and this is set as the average diameter of the protrusion. In addition, the highest value among the binarized individual projection portions is set as the height of the projection, and this is obtained for each projection. Change this measurement from one place to another
The number of protrusions was determined 500 times, and the average value of the heights of all the measured protrusions was taken as the average height. Moreover, the magnification of the scanning electron microscope is selected to be a value between 1000 and 8000 times. In some cases, a high-precision optical interference type three-dimensional surface analyzer (TOPO-3D manufactured by WYKO, objective lens:
The height information obtained by using a high resolution camera (40 to 200 times, effective use of high resolution camera) may be read as the SEM value and used.

(5) Surface layer particle concentration ratio The secondary ion mass spectrum (SIMS) was used to determine the concentration ratio of the highest concentration element of the particles in the film and the carbon element of the thermoplastic resin. Concentration
Analyze in the thickness direction. The ratio of the particle concentration A at the outermost surface particle concentration (point of depth 0) measured by SIMS and the maximum concentration B obtained by further conducting the analysis in the depth direction, A
/ B was defined as the surface particle concentration ratio. The measuring device and conditions are as follows.

Measuring device Secondary ion mass spectrometer (SIMS) A-DIDA3000 manufactured by ATOMIKA, West Germany Measuring conditions Primary ion species: O ₂ ⁺ Primary ion accelerating voltage: 12kv Primary ion current: 200nA Raster area: 400 μm □ Analysis area: Gate 30% Measuring vacuum degree: 6.0 × 10 ⁹ Torr E-GUN: 0.5KV-3.0 A (6) Single particle index The cross section of the film was photographically observed with a transmission electron microscope (TEM). , Detect particles. If the observation magnification is set to about 100,000, one particle that cannot be further divided can be observed. When the total area occupied by particles is A and the area occupied by aggregates in which two or more particles are aggregated is B, (A
-B) / A is a single particle. The TEM conditions are as follows: 1 field-of-view area: 2 μm ² measurement is carried out at 500 different fields.

-Device: JEM-1200EX manufactured by JEOL- Observation magnification: 100000 times-Slice thickness: Approximately 1000 angstroms (7) Particle size ratio In the measurement of the above (1), the average value of the major axis of each particle /
It is the ratio of the average value of the minor axis. That is, it is calculated by the following formula.

Major axis = ΣD1i / N Minor axis = ΣD2i / N D1i and D2i are the major axis (maximum diameter) and minor axis (shortest diameter) of each particle, and N is the total number.

(8) Thickness of Thermoplastic Resin A Layer in Laminated Film Using a secondary ion mass spectrometer (SIMS), the element and heat caused by the highest concentration of particles in the film are measured. The carbon element concentration ratio (M ⁺ / C ⁺ ) of the thermoplastic resin is used as the particle concentration, and analysis is performed in the depth (thickness) direction from the surface of the thermoplastic resin A layer. 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 at the depth [I] starts to decrease again. Based on this concentration distribution curve, the depth [I
I] (here, II> I) was taken as the laminated thickness. The conditions are the same as in measurement method (5).

When the most abundant particles in the film are organic polymer particles, it is difficult to measure by SIMS, so XPS (X-ray photoelectron spectroscopy), IR (infrared spectroscopy) or The depth profile may be measured, and the laminated thickness may be obtained by the same method as described above.

(9) Scratch resistance A film slit into a tape having a width of 1/2 inch was placed on a guide pin (surface roughness: Ra of 100 nm) using a tape running tester. Let it run. (Running speed 10
00m / min, 10 passes, winding angle: 60 °, running tension: 70g). At this time, the scratches in the film were observed with a microscope, and it was judged that the scratches having a width of 2.5 μm or more per tape width were excellent when less than 2, 2 or more and less than 10 were good, and 10 or more were defective. Good is desirable, but good is practically usable.

(10) Scraping resistance A film was slit into a tape shape having a length of 30 cm and a width of 1/2 inch, and a laser blade was vertically pressed against the tape.
With 0.5 mm pushed in, the load is 500 g / 0.5 inch,
The width in the depth direction of the shavings adhering to the laser blade when traveling at a speed of 2 m / min was determined by taking a micrograph (× 160). When the width of the shavings in the depth direction is less than 5 μm (⊚), 5 μm or more and less than 10 μm (◯), 10 μm
The above is (x). Needless to say, the smaller the adhesion depth of the shavings, the better the abrasion resistance.

(11) Intrinsic viscosity of copolymerized polyester: [η] was measured at 25 ° C. using an o-chlorophenol solvent.

(12) Water-solubility of copolyester 2 g of copolyester was put in 100 g of water to prepare 60
After stirring and dissolving at 2 ° C. for 2 hours and cooling, the mixture is filtered with a 2 μm filter. Water solubility was determined by the dissolved state and the amount of supernatant.

◯: The aqueous solution was transparent or slightly clouded, but almost no filtered matter was observed. Δ: The aqueous solution was slightly clouded, and filtered matter was observed. X: It was difficult to dissolve. The aqueous solution was strongly cloudy, and a large amount of filtered material was observed. (13) Adhesion of magnetic paint Coated polyester and wax solutions were applied on a polyester film substrate to form an easy-adhesion layer, and to the easy-adhesion layer surface. Magnetic paint (Daiferakoto CAD-430
1: A coating consisting of 100 parts by weight of Dainichiseika Kogyo Co., Ltd. and 1 part by weight of a curing agent, Sumidule N75 (Sumitomo Bayer Co., Ltd.) was coated with a bar coat to a thickness of 5 μm after drying.
Coating, and dried at 100 ° C. for 5 minutes to form a coating layer.

Separately, on a PET film (50 μm) substrate, Seika Bond (E270) which is an adhesive manufactured by Dainichiseika Co., Ltd.
/ C-26 = 10/2 (weight ratio)) was applied by a bar coater so as to have a thickness of 8 μm after drying, and dried at 60 ° C. for 1 minute to form a coating layer. Two pieces of PET coated with this adhesive
The sample coated with the above-mentioned magnetic paint is sandwiched between the substrates, and they are laminated with a roller so that air bubbles do not enter. Further, the press roll of the laminator having a surface temperature of 100 ° C. is made to reciprocate once. After aging this sample at 40 ° C. for 48 hours or more, a strip sample having a width of 15 mm was peeled off at 90 ° between the easy-adhesion layer and the magnetic coating material using a Tensilon tensile tester (pulling speed: 200 mm / min) to improve adhesion. It was measured. It was judged according to the following criteria.

⊚: 250 g / 15 mm width or more O: 200 g / 15 mm width or more, 250 g / 15 mm
Less than width Δ: 150 g / 15 mm width or more, 200 g / 15 mm
Less than width x: less than 150 g / 15 mm width (14) Antistatic property A polyester film on which no easy-adhesion layer is laminated is wound around the surface of the metal drum rotating body, and the easy-adhesion layer is laminated while rotating to form an easy-adhesion layer of the film. Load at the end is 255g
And rub along the metal drum rotating body for 5 seconds. Immediately after that, the electrostatic potential of the film was measured by an electrostatic meter to determine the antistatic property.

◯: Charge amount +3 KV or more to less than +7 KV Δ: Charge amount 0 KV or more to less than +3 KV ×: Charge amount less than 0 KV (minus charge) or +7 KV or more Electrostatic meter: Statileon TH type manufactured by Shishido Electrostatic Co., Ltd. Measuring distance 50mm from the head opening Rotating metal drum: size 65mm width x 150mmφ, rotation speed 860rpm Measurement sample: 30mm width x 300mm length (15) Blocking resistance Easy-adhesion layer surface of film with easy-adhesion layer and biaxially oriented PE
Stacked T-films (Stacking area: 3 cm x 4
cm) with a load of 500 g / 12 cm ² at 40 ° C 8
After leaving it in 0% RH for 24 hours, the shearing stress of the overlapped portion was measured with a Tensilon tensile tester at a tensile speed of 2
It was measured at 0 cm / min, and judged according to the following criteria.

[0085] ◎: 0kg / cm ² (not completely ^{blocking) ○: 0.1kg / cm 2 ~1kg} / cm 2 or less ^{△: 1kg / cm 2 ~3kg /} cm 2 or less ×: 3kg / cm ² or more (16) Smoothness (Static friction coefficient μs, Dynamic friction coefficient μd) The friction coefficient between films is ASTM-D-1894-
According to No. 63, static friction coefficient μs and dynamic friction coefficient μd were measured using a surface quality measuring device HEIDON-14DR manufactured by Shinto Kagaku Co., Ltd., sample moving speed 200 mm / min, load 20
0 g, measured under the condition of contact area 63.5 mm x 63.5 mm, and analyzing recorder-TYPE: HEIDO
N3655E-99 was recorded and evaluated, and the slipperiness was judged according to the following criteria.

○: μs = less than 0.8 Δ: μs = 0.8 or more and less than 1.3 ×: μs = 1.3 or more (17) Solvent resistance The easily-adhesive surface was swabbed with MEK / THF (methyl ethyl ketone). / Tetrahydrofuran) in an equal amount of mixed solvent, 50
The solvent resistance was judged according to the following criteria from the remaining area of the easy-adhesion layer after rubbing 10 times while applying a load of g.

(18) Thickness of coating layer Using a transmission electron microscope HU-12 manufactured by Hitachi Ltd., an ultrathin film section of the laminated film was observed to determine the thickness.

(19) Surface Roughness According to JIS-B-0601, a stylus type surface roughness meter ET-10 manufactured by Kosaka Laboratory Ltd. was used and the cutoff was 0.02.
The average surface roughness Ra was determined at 5 mm and a measurement length of 4 mm.

(20) S / N of magnetic recording medium 8 mm VTR with magnetic recording medium incorporated in VTR cassette
It was a tape. A 100% chroma signal was recorded on this tape by a TV test waveform generator (TG7 / U706) made by Shibasoku using a VTR for home use, and from the reproduced signal, chroma S was made by a color video noise measuring instrument made by Shibasoku (925D / 1). / N was measured.

This chroma S / N is a commercially available Hi8
When the S / N was 1 dB or more higher than the tape (8 mm VTR tape for high band, Hi8MP120 manufactured by Sony), the S / N was good, and when the S / N was less than 1 dB, the S / N was bad.

(21) Durability of magnetic surface Using the Hi8 VTR manufactured by SONY,
After repeating reproduction and rewinding 1000 times under the condition of 80% RH, the above S / N is measured again, and if the decrease in S / N is less than 1 dB compared to before running, the durability is good, and if it is 1 dB or more, the durability is good. It was judged to be poor.

Next, the present invention will be explained based on examples, but the present invention is not necessarily limited to these.

[0093]

【Example】

Examples 1 to 6 and Comparative Examples 1 to 8 Ethylene glycol slurries containing crosslinked polystyrene particles having different average particle sizes and spherical silica particles derived from colloidal silica were prepared, and the ethylene glycol slurries were prepared at 190 ° C. After heat treatment for 1.5 hours, after transesterification with dimethyl terephthalate and polycondensation, polyethylene terephthalate containing 0.3 to 55% by weight of the particles.
Pellets (hereinafter abbreviated as PET) were prepared. Using the pellets, a thermoplastic resin A was prepared, and PET containing 0.3% by weight of spherical silica particles having a diameter of 0.03 μm was produced by a conventional method to obtain a thermoplastic resin B.
Each of these polymers was dried under reduced pressure (3 Torr) at 180 ° C. for 3 hours. The thermoplastic resin A is supplied to the extruder 1 and 2
It is melted at 85 ° C., further, the thermoplastic resin B is supplied to the extruder 2 and melted at 280 ° C., and these polymers are subjected to confluent lamination with a confluent block having a rectangular laminated portion, and the electrostatic applied cast method is used. It was wound around a casting drum having a surface temperature of 30 ° C. and cooled and solidified to prepare an unstretched film having a three-layer structure having two layers or a thermoplastic resin A layer on both sides. At this time, the total thickness and the thickness of the thermoplastic resin A layer were adjusted by adjusting the discharge amount of each extruder (however, Comparative Example 7 was a single layer A layer, and Comparative Example 8 was a single layer B layer). This unstretched film was stretched 4.5 times in the longitudinal direction at a temperature of 80 ° C. This stretching is 2
The difference in peripheral speed of the rolls for each set was performed in four stages. This uniaxially stretched film was coated in-line on the A layer side so as to have the constitution of the C layer shown in Table 1 and Table 2, respectively,
The coated uniaxially stretched film was stretched at a stretching rate of 2000% / min at 100 ° C. by 4.0 times in the width direction using a stenter, and heat-treated at 200 ° C. for 5 seconds under a tension of 2 kg / m in the longitudinal direction. A biaxially oriented laminated film having a total thickness of 15 μm and a thermoplastic resin A layer thickness of 0.03 to 4 μm was obtained. The parameters of the present invention for these films are as shown in Tables 1 and 2.

In the present invention, the structure is A / B layer or A
The copolymerized polyester in which the polyoxyalkylene glycol component of the C layer laminated on the laminated film such as / B / A layer is contained in an amount of 1% by weight or more and less than 40% by weight will be described. The copolymerized polyester of the present invention is not particularly limited as long as the polyoxyalkylene glycol component is contained in an amount of 1% by weight or more and less than 40% by weight, but water solubility or water dispersibility is preferable. Among them, water-soluble copolyester is particularly preferable.

The method for producing the water-soluble copolyester is not particularly limited. For example, referring to the water-soluble copolyester in Example 1, 71 parts by weight of dimethyl terephthalate, 15 parts by weight of dimethyl 5-sodium sulfoisophthalate, 50.0 parts by weight of ethylene glycol, 6.0 parts by weight of diethylene glycol. Department,
21 parts by weight of polyethylene glycol having a number average molecular weight of 600, 0.1 part by weight of calcium acetate, 0.3 part by weight of lithium acetate, and 0.03 part by weight of antimony trioxide were added, and the transesterification reaction was carried out by a conventional method. 0.05 parts by weight of trimethyl phosphate were added. Then, the temperature was gradually raised and the pressure was reduced, and finally a polycondensation reaction was carried out at 280 ° C. and 1 mmHg or less to obtain a water-soluble copolyester.
The composition of the obtained water-soluble copolyester was analyzed by NMR ( ¹³
As a result of measurement by C-NMR spectrum), the acid component was 87.5 mol% terephthalic acid, 12.5 mol% 5-sodium sulfoisophthalic acid, and the glycol component was 95 mol% ethylene glycol and 5 mol% diethylene glycol. Mol%
The polyethylene glycol content was 20% by weight and the intrinsic viscosity was 0.83 dl / g.

2 g of the obtained water-soluble copolyester was put in 100 g of water, dissolved by stirring at 80 ° C. for 2 hours, cooled, and then filtered with a 2 μm filter to obtain a water-soluble copolyester aqueous solution having a concentration of 2% by weight. Got The aqueous solution of the water-soluble copolyester was almost transparent, and no filter-filtered substance was observed.

On the other hand, as the wax to be mixed with the water-soluble copolyester, 10 weight parts of the oxidized wax having a solid content concentration of 2% by weight was added to the water-soluble copolyester aqueous solution, followed by thorough mixing and stirring to obtain the coating composition of the present invention. And

[C Layer Composition] 1) Water-soluble copolyester 90 parts by weight 2) Wax: Oxidized wax 10 parts by weight To make the above oxidized wax into an aqueous dispersion, a nonionic surfactant, a phosphoric acid ester, and ammonium oleate. , 2-
1 part by weight of each of amino-2-methylpropanol was added,
The mixture was vigorously stirred in water, and an ultrasonic dispersion machine was used to prepare an aqueous dispersion having a total solid content of 2% by weight.

The compositions of the C layer in Examples 2 to 8 and Comparative Examples 1 to 8 are as shown in Table 1 and Table 2, respectively.

The scratch resistance and abrasion resistance on the C layer side of the obtained film were evaluated, and the adhesion to the magnetic layer was evaluated.
The antistatic property was evaluated. Further, a magnetic layer was applied to the surface of the layer C of the obtained film to prepare a tape, which was wound under ordinary winding tension to obtain a magnetic tape. When the parameter of the present invention was within the range, each property showed a good value as shown in Tables 3 and 4, but when it was not, an excellent film satisfying all the respective properties could not be obtained. It was

Example 7 The procedure of Example 7 was repeated except that the polyethylene terephthalate used in Example 1 was replaced with a water-soluble copolyester and an oxidized wax as the base film. An adhesive polyester film having a coating layer thickness of 0.04 μm and a film thickness of 10 μm was obtained in exactly the same manner as in Example 1. That is, 80% by weight of a polyester composed of 87.5 mol% of terephthalic acid as an acid component, 12.5 mol% of 5-sodium sulfoisophthalic acid, 95 mol% of ethylene glycol as a diol component, and 5 mol% of diethylene glycol. And 10 parts by weight of a mixture of 90 parts by weight of a water-soluble copolyester consisting of 20% by weight of polyethylene glycol having a molecular weight of 600 and 10 parts by weight of oxidized wax were mixed with polyethylene terephthalate and used. As the coating agent, as shown in Table 1, water-soluble copolyester / oxidized wax = 90/10 was used. The characteristics of the film thus obtained are shown in Table 3,
Thus, it can be seen that the base layer having sulfonic acid sodium salt, polyethylene glycol and oxidized wax is more excellent in slipperiness, blocking resistance and adhesiveness.

Example 8 The laminated film of the present invention in which the C layer was laminated in exactly the same manner as in Example 1 except that polyethylene 2,6-naphthalate polymer was used as the base film instead of polyethylene terephthalate. Got The results are shown in Table 3, and it was an excellent film as in Examples 1 to 7.

Comparative Example 9 As shown in Table 2, the laminated film having the structure used in Example 1 was wound as it was without laminating the C layer. The evaluation results of this film are shown in Table 4. The film was inferior in magnetic coating adhesion and antistatic property.

[0104]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[0105]

The film containing the thermoplastic resin A and particles as the main components is laminated on at least one side of the film containing the thermoplastic resin B as the main component, and the thickness of the laminated film of the thermoplastic resin A is 0. 005 to 5 μm, the average particle diameter of the particles contained in the laminated film is 0.1 to 1 of the laminated thickness.
0 times, the content of the particles in the laminated film is 0.1 to 50.
A biaxially oriented thermoplastic resin film which is% by weight,
A laminated film comprising a layer of a copolyester containing a polyoxyalkylene glycol component in an amount of 1% by weight or more and less than 40% by weight on at least one side of the film. It is excellent in smoothness, water solubility, blocking resistance and solvent resistance, and is preferably used for magnetic recording materials, various photographic materials, packaging materials, electrical insulating materials, general industrial materials and the like.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B29K 67:00 105: 16 B29L 9:00

Claims (8)

[Claims] 1. A film A containing a thermoplastic resin A and particles as a main component, and a film B containing a thermoplastic resin B as a main component.
Is laminated on at least one surface of the film A, the thickness of the film A is 0.005 to 5 μm, the average particle diameter of the particles contained in the film A is 0.1 to 10 times the thickness of the film A,
A biaxially oriented thermoplastic resin laminated film having a content of the particles in the film A of 0.1 to 50% by weight, wherein the polyoxyalkylene glycol component is 1% by weight or more on at least one surface of the laminated film. , A laminated film formed with a layer (C layer) made of a copolyester having a content of less than 40% by weight. 2. The laminated film according to claim 1, wherein the copolyester comprises a water-soluble or water-dispersible copolyester. 3. The C layer contains an oxidized wax and / or a natural wax.
Or the laminated film according to 2. 4. The polyoxyalkylene glycol content [A% by weight] and the ethylene glycol oligomer content [B mol%] of the copolymerized polyester satisfy the following formula (1), and ethylene glycol 4. The laminated film according to claim 1, wherein the oligomer content is 1 mol% or more and 20 mol% or less. 1 ≦ A / B ≦ 10 (1) 5. The C layer is formed of a mixture mainly composed of 70 to 99.9% by weight of the water-soluble copolyester and 30 to 0.1% by weight of an oxidation wax and / or a natural wax. The laminated film according to any one of claims 1 to 4, which is characterized in that. 6. The polyoxyalkylene glycol component is polyethylene glycol, and the number average molecular weight thereof is 400 to 10,000.
5. The laminated film according to 5 above. 7. The laminated film according to claim 1, wherein the polyester film substrate is made of a polymer containing ethylene terephthalate or ethylene-2,6-naphthalate as a main constituent. 8. A polyester film substrate containing 5 ppm or more and less than 20% by weight of a polymer copolymerized with a compound having a sulfonic acid and / or a salt thereof, polyethylene glycol, and an oxidized wax and / or a natural wax. The laminated film according to any one of claims 1 to 7, which comprises the above composition.