JP3211363B2 - Laminated polyethylene-2,6-naphthalate film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to polyethylene-2,6
The present invention relates to a naphthalate film, and more particularly to a polyethylene-2,6-naphthalate film suitable as a magnetic recording medium.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate films have been mainly used for films used for industrial purposes, such as magnetic tape applications, electrical insulation applications such as capacitors, packaging applications, photographs, It is used in various fields such as plate making. In particular, as a base material for a magnetic recording material, the base material had remarkably excellent characteristics and was in a situation where other films could not follow. However, in recent years, magnetic recording media have been rapidly improved, and from the viewpoint of improving information recording density, the demand for thinning and flattening the base film of the magnetic recording media has become more severe than before. In an attempt to improve the recording area per unit volume by thinning, it has been difficult to achieve a sufficient thinning of a polyethylene terephthalate film while maintaining practical strength. The base film surface of such a high-density recording medium is required to be flatter. However, various bad effects appear as the film surface becomes flat. For example, when a metal pin and a tape come into contact with each other at a high speed, such as a magnetic tape, friction and wear between the two become large, causing scratches and abrasion powder on the tape.

[0003]

Means for Solving the Problems The present inventor has made intensive studies in view of the above-mentioned problems, and as a result, has found that specific polyethylene-2,6-
The inventors have found that naphthalate films are useful, and have completed the present invention. That is, the gist of the present invention is:
On at least one side of a polyethylene-2,6-naphthalate film having a thickness of 9 μm or less, 0.5 to 40 organic particles are added.
A laminated polyethylene-2,6-naphthalate film characterized by being a laminated film having a coating layer containing at least 1% by weight and simultaneously satisfying the following formulas (1) to (4). F5 value in film longitudinal direction ≧ 1.5 × 10 ⁸ Pa ... Young's modulus in film longitudinal direction ≧ 5.9 × 10 ⁹ Pa… Young's modulus in film lateral direction ≧ 5.9 × 10 ⁹ Pa… Center line of coating layer Average surface roughness ≦ 0.020 μm ...

Hereinafter, the present invention will be described in more detail. In the present invention, polyethylene-2,6-naphthalate means that at least 80 mol% of its constituent units are ethylene-2,6-naphthalate.
-Polyethylene-2,6-naphthalate which is naphthalate. Examples of the copolymer components other than the above-mentioned superior components include, for example, diol components such as diethylene glycol, propylene glycol, neopentyl glycol, polyethylene glycol and polytetramethylene glycol, terephthalic acid, isophthalic acid, 2,7-naphthalenedicarboxylic acid, A dicarboxylic acid component such as 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid and an ester-forming derivative thereof, and an oxymonocarboxylic acid such as oxybenzoic acid and an ester-forming derivative thereof can be used.

If the degree of polymerization of the polyethylene-2,6-naphthalate used in the present invention is too low, the mechanical properties to be described later deteriorate, so that the intrinsic viscosity is usually 0.40 or more, preferably 0.1-0. 5 to 0.7. The carboxyl group value of the polyethylene-2,6-naphthalate used in the present invention is preferably 15 to 100 equivalents / ton, more preferably 40 to 95 equivalents / ton, and particularly preferably 50 to 90 equivalents / ton. is there. Since the adhesion to the coating layer is improved by the presence of the carboxyl group, the carboxyl group value is preferably 15 or more. If the carboxyl group value is too large, the heat resistance and mechanical properties of polyethylene-2,6-naphthalate have. It is preferably 100 or less, since the mechanical characteristics may be deteriorated.

[0006] The polyethylene-2,6-naphthalate film of the present invention contains so-called added particles, precipitated particles, catalyst residues, etc., which form projections on the film surface, as long as the electromagnetic conversion characteristics described below are not deteriorated. May be. In addition, as an additive other than the above-mentioned protrusion-forming agent, if necessary, an antistatic agent, a stabilizer, a lubricant, a cross-linking agent, an anti-blocking agent, an antioxidant, a coloring agent, a light-blocking agent, an ultraviolet absorber, etc. May be contained. The polyethylene-2,6-naphthalate film of the present invention may have a multilayer structure as long as properties finally obtained satisfy the requirements of the present invention. In the case of a multilayer structure, some of the layers may be other than the polyethylene-2,6-naphthalate film layer.

In the present invention, a coating layer containing particles is provided on at least one surface of the polyethylene-2,6-naphthalate film in order to impart lubricity while maintaining the surface flatness of the substrate film. Usually 5 of such particles
0% by weight or more, preferably 70% by weight or more is organic particles. In general, inorganic particles such as colloidal silica used as the lubricating particles have poor affinity for the resin binder constituting the coating layer described later and are easily dropped off. The effect of improving flaws is insufficient. That is, when the film coating layer surface comes into contact with various rolls or the like in a film manufacturing process or a magnetic tape manufacturing process, particles in the coating layer fall off and reduce the wear resistance of the entire coating layer, or This is because a scratch may occur.

The organic particles used in the present invention are compounds substantially composed of organic compounds, such as polystyrene, polyethylene, polyamide, polyester, polyacrylate, epoxy resin, polyvinyl acetate or polyvinyl chloride, and the like. Fine particles containing a crosslinking agent consisting of a homopolymer or a copolymer as necessary, a silicone resin,
Fine particles such as a fluororesin can be used, but crosslinked polymer particles that cause less thermal deformation of the particles are preferable. Examples of the crosslinked polymer particles include, for example, a copolymer of a monovinyl compound having one aliphatic unsaturated bond in a molecule and a compound having two or more aliphatic unsaturated bonds in a molecule as a crosslinking agent However, the present invention is not limited thereto, and examples thereof include a thermosetting phenol resin, a thermosetting epoxy resin, a thermosetting urea resin, and a benzoguanamine resin. Further, the organic particles in the present invention may have a multilayer structure. In particular, (1) one selected from acrylic acid, methacrylic acid and their alkyl esters, styrene and their alkyl derivatives
Crosslinked polymer particles obtained by copolymerizing at least one compound with at least one compound selected from (2) divinylbenzene and ethylene glycol dimethacrylate are preferably used.

The shape of the organic particles used in the present invention is spherical,
The shape may be any of a block shape, a flat shape, and the like, and these shapes can be properly used depending on a desired surface property of the coating layer. The particle size distribution of the organic particles is preferably close to monodispersion. The particle size distribution value is preferably 1.60 or less, more preferably 1.50 or less, and particularly preferably 1.40 or less. Here, the particle size distribution value is d
₂₅ / d ₇₅ (d ₂₅ and d ₇₅ are defined as particle diameters (μm) corresponding to 25% and 75% of the total volume, respectively, when the integrated volume of the particle group is measured from the large particle side). The ratio of the organic particles in the coating layer is in the range of 0.5 to 40% by weight, preferably in the range of 1 to 20% by weight. When the proportion of the organic particles in the coating layer is less than 0.5% by weight, the effect of preventing sticking and the effect of improving slipperiness are insufficient. If the ratio of the organic particles in the coating layer exceeds 40% by weight, the strength of the coating film is reduced, and the organic particles may be undesirably dropped.

As a resin binder of the organic particles constituting the coating layer, polyester, polyamide, polystyrene, polyacrylate, polycarbonate, polyarylate, polyvinyl chloride, polyvinylidene chloride, polyvinylidene, which have excellent adhesion to a magnetic layer or the like. Examples thereof include resins such as butyral, polyvinyl alcohol, and polyurethane, and copolymers and mixtures of these resins, but are not limited thereto. The most preferred resin binder among these is a polyester resin. The following polyvalent carboxylic acid and polyvalent hydroxy compound can be exemplified as components constituting such a polyester-based resin. That is, as the polyvalent carboxylic acid, terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,
4'-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4
-Cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, trimellitic anhydride , Phthalic anhydride, p-hydroxybenzoic acid, monopotassium trimellitate and ester-forming derivatives thereof can be used.

On the other hand, polyhydric hydroxy compounds include ethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol , P-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol,
Polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane,
Sodium dimethylolethylsulfonate, potassium dimethylolpropionate and the like can be used. One or more of these compounds are appropriately selected, and a polyester resin is synthesized by a conventional polycondensation reaction. In addition to the above, a composite polymer having a polyester component such as a so-called acrylic graft polyester or a polyester polyurethane obtained by chain-extending a polyester polyol with an isocyanate described in JP-A-1-165633 is also a polyester-based polymer of the present invention. Included in resin.

The resin binder in the present invention is preferably a coating agent using water as a medium. When water is used as the medium, a coating agent forcibly dispersed with a surfactant or the like may be used, but a hydrophilic nonionic component such as a polyether or a cationic compound such as a quaternary ammonium salt is preferable. It is a self-dispersible coating agent having a group, and more preferably a water-soluble or water-dispersible resin coating agent having an anionic group. The resin having an anionic group referred to here is a resin having a compound having an anionic group bonded to the resin by copolymerization, grafting, or the like.
It is appropriately selected from carboxylic acid, phosphoric acid and their lithium salts, sodium salts, potassium salts, ammonium salts and the like. The ratio of the anionic group to the resin solid content is 0.1%.
The range of from 0.5 to 8% by weight is preferred. When the amount of the anionic group is less than 0.05% by weight, the water solubility or water dispersibility of the resin tends to be poor. When the amount of the anionic group exceeds 8% by weight, the water resistance of the coating layer is poor, or the resin absorbs moisture. The films may stick to each other.

[0013] The final dry thickness of the coating layer is preferably in the range of 0.003 to 2 µm, more preferably 0.01 to 1 µm, particularly preferably 0.03 to 0.2.
It is in the range of μm. When the thickness of the coating layer is larger than 2 μm, the films tend to adhere to each other, or the film sticks to the roll during the process, particularly when the coating film is re-stretched for the purpose of increasing the strength of the film. It may be easier. The thickness of the coating layer is 0.00
If it is less than 3 μm, a uniform coating may not be obtained.
The ratio (d / t) of the average particle size d (μm) of the organic particles in the coating layer to the dry thickness t (μm) of the coating layer is preferably 0.5 to 5, more preferably 0.7. To 3, particularly preferably 0.8 to 2. If d / t is 0.5 or less, the effect of preventing adhesion and the effect of improving slipperiness tend to be insufficient. If d / t exceeds 5, the film becomes cloudy or organic particles fall off. In some cases, when used as a magnetic recording medium, the magnetic conversion characteristics such as the S / N ratio may be deteriorated or the dropout may increase.

[0014] The coating solution for obtaining the coating layer is formed into a methylol or an alkylol as a crosslinking agent in order to improve the fixing property (blocking property), water resistance, solvent resistance and mechanical strength of the coating layer. Urea-based, melamine-based, guanamine-based, acrylamide-based, polyamide-based compounds, epoxy compounds, aziridine compounds, block polyisocyanates, silane coupling agents, titanium coupling agents, zirco-aluminate coupling agents, peroxides , A heat- or photo-reactive vinyl compound or a photosensitive resin. Furthermore, if necessary, it may contain an antifoaming agent, a coating improver, a thickener, an antistatic agent, an organic lubricant, an antioxidant, an ultraviolet absorber, a foaming agent, a dye, a pigment, etc. Good.

The above-mentioned coating solution is applied to polyethylene-2,6-
As a method of applying to a naphthalate film, a reverse roll coater, a gravure coater, and a coating method described in “Coating method”, published by Yuji Harasaki, Maki Shoten, 1979,
Using a rod coater, an air doctor coater, or another coating device, coating may be performed on a film that has already been biaxially stretched, or may be performed in a biaxially stretched film manufacturing process. As a method of applying in a biaxially stretched film manufacturing process, a polyethylene-2,6-naphthalate film stretched uniaxially in the longitudinal direction is applied, and in a dried or undried state, a direction perpendicular to the further uniaxially stretched direction. The method of performing heat treatment after stretching the film has a great advantage in view of the production cost since film formation and coating and drying can be performed at the same time, and is particularly preferably employed, but is not limited thereto.

The stretching step for obtaining the above-mentioned film comprises:
The stretching is preferably performed at 120 to 180 ° C., and the stretching ratio is at least 4 times or more, preferably 6 to 20 times, in area ratio. The stretched film is heat-treated at 150 to 250 ° C. Further, it is preferable that the resin is relaxed in the longitudinal direction and the transverse direction by 0.1 to 20% in the maximum temperature zone of the heat treatment and / or the cooling zone at the heat treatment outlet. In particular, 1
Uniaxially stretched polyethylene-2,6-stretched 2 to 6 times in the longitudinal direction of the film by a roll stretching method at 20 to 180 ° C
A coating solution is applied to a naphthalate film and dried appropriately or without drying.
The naphthalate uniaxially stretched film is immediately stretched 2 to 6 times at 120 to 180 ° C in the direction perpendicular to the previous stretching direction, and 1.01 to 1.9 at 120 to 180 ° C in the longitudinal direction of the film.
A method of performing a heat treatment at 150 to 250 ° C. for 1 to 600 seconds is preferable. Before the heat treatment, it is also preferable to increase the strength in the transverse direction by re-stretching the film in a direction perpendicular to the longitudinal direction of the film at 120 to 230 ° C. by 1.01 to 1.9 times. According to this method, the coating layer can be dried at the same time as the stretching, and the thickness of the coating layer can be reduced according to the stretching ratio. Thus, a film suitable as a polyethylene-2,6-naphthalate film substrate Can be manufactured relatively inexpensively.

The coating solution in the present invention is polyethylene-
It may be applied to only one side of the 2,6-naphthalate film or may be applied to both sides. When applied on only one side, a coating layer using a coating solution other than the coating liquid of the present invention is formed on the opposite side as necessary, and the polyethylene-2,6-naphthalate film of the present invention has other properties. Can also be given. In addition, the applicability of the coating agent to the film,
To improve the adhesiveness, the film may be subjected to a chemical treatment or a discharge treatment before coating. Further, in order to improve the surface characteristics of the coating layer of the biaxially stretched polyethylene-2,6-naphthalate film of the present invention, the coating layer may be subjected to a discharge treatment after the formation of the coating layer.

The film of the present invention has a strength F5 at 5% elongation in the machine direction of 1.5 × 10 ⁸ Pa or more, a Young's modulus in the machine direction of 5.9 × 10 ⁹ Pa or more, and a Young's modulus in the transverse direction. Is 5.9 × 10 ⁹ Pa or more. With a film that does not satisfy such strength, it is difficult to achieve thinning.
That is, when tension is applied during use, the film elongation is large, which is not preferable. In particular, when used as a base film of a magnetic recording medium, a large elongation is not preferable because distortion of a screen called skew occurs and sound quality deteriorates. The term “thinning” as used in the present invention means that the thickness of the base film is 9 μm or less, preferably 7 μm or less, more preferably 5 μm or less. The density of the polyethylene-2,6-naphthalate film thus obtained is usually 1.360 g / cm.
³ or more, preferably 1.370 g / cm ³ or more. If the density is low, the dimensional stability of the film tends to deteriorate. In order to maintain the dimensional stability of the film, the shrinkage at 150 ° C. for 30 minutes is usually 5% or less, preferably 3% or less, more preferably 2% or less in both the longitudinal and lateral directions of the film. Physical properties can be achieved by relaxation at the time of heat setting.

The center line average surface roughness (Ra) of the surface of the coating layer formed as described above is 0.020 μm or less;
Preferably, it is in the range of 0.002 to 0.020 μm, more preferably 0.003 to 0.015 μm, and particularly preferably 0.003 to 0.010 μm. Ra is 0.
If it is less than 002 μm, the slipperiness is insufficient and the workability deteriorates. On the other hand, when Ra exceeds 0.020 μm, the surface is too rough, and when used as a base film of a magnetic recording medium, the magnetic conversion characteristics such as the S / N ratio are deteriorated and the dropout is increased. Is not preferred.

[0020]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In addition, the measuring method and definition of various physical properties and characteristics in the present invention are as follows. In Examples and Comparative Examples,
"" Means "parts by weight". (1) Tensile strength (F5 value) Tensile tester Intesco Model 20 manufactured by Intesco Corporation
Using a type 01, a sample film having a length of 50 mm and a width of 15 mm was pulled at a speed of 50 mm / min in a room adjusted to a temperature of 23 ° C. and a humidity of 50% RH, and the strength at 5% elongation was defined as F5 value. (2) Young's modulus Intesco Corporation tensile tester Intesco Model 200
Using a mold 1, a sample film having a length of 300 mm and a width of 20 mm was pulled at a strain rate of 10% / min in a room adjusted to a temperature of 23 ° C. and a humidity of 50% RH, and the first straight line of a tensile stress-strain curve was obtained. It was calculated by the following equation using the parts. E = Δσ / Δε (where E is Young's modulus (Pa), and Δσ is 2
The stress difference due to the original average cross-sectional area between points, Δε is the strain difference between the same two points)

(3) Center line average surface roughness (Ra) It was determined as follows using a surface roughness measuring instrument (SE-3F) manufactured by Kosaka Laboratory Co., Ltd. That is, a reference length L (2.55 mm) from the film cross-section curve in the direction of its center line.
, And the center line of the extracted part is the x-axis,
When the roughness curve was represented by y = f (x) using the direction of the vertical magnification as the y-axis, ten values given by the following equations were measured, and the average value was defined as Ra. The tip radius of the stylus was 2 μm, the load was 30 mg, and the cutoff value was 0.08 mm.

[Number 1] Ra = (1 / L) ∫ 0 L | f (x) | dx (4) Test of sessile sessile (blocking resistance) is, 40 ° C. by hot pressing at a constant temperature and humidity chamber, 80% RH ASTM-D-18, a film held for 20 hours at 10 kgf / cm @ 2
The peel strength was measured by the method of No. 93. The criteria are as follows. ：: less than 5 gf / cm Δ: 5 gf / cm or more and less than 10 gf / cm ×: 10 gf / cm or more

(5) Slipperiness (F / F μd) On a smooth glass plate, two films cut to a width of 15 mm and a length of 150 mm are stacked, a rubber plate is placed thereon, and a load is further placed thereon. And the frictional force was measured by sliding the ^two films at 20 mm / min with the contact pressure of the two films being 2 g / cm ² . The coefficient of friction at the point of sliding by 5 mm was defined as the dynamic friction coefficient (F / F μd), and the evaluation was made according to the following criteria. ：: μd ≦ 0.8 ×: μd> 0.8

(6) Wear Characteristics Evaluation was made based on the amount of white powder generated. The film was run 1000 m while the film was in contact with the hard chrome fixing pin, and the abrasion white powder adhering to the hard chrome fixing pin was visually observed, and evaluated by the following three grades of ○, Δ, and ×. The film speed was 13 m / min, the hearing was about 200 gf, and the winding angle of the film around the pin was 135 degrees. ：: No white powder generated △: Small white powder generated ×: Large white powder generated

(7) Magnetic Tape Characteristics (Characteristics of Magnetic Recording Medium) First, the following magnetic paint was applied to a film, and a magnetic layer was formed so that the film thickness after drying was 5 μm. That is,
200 parts of magnetic fine powder, 30 parts of polyurethane resin, 10 parts of nitrocellulose, 10 parts of polyvinyl chloride copolymer, lecithin 5
, 100 parts of cyclohexanone and 300 parts of methyl ethyl ketone were mixed and dispersed in a ball mill for 48 hours, and then 5 parts of a polyisocyanate compound was added to form a magnetic paint. After this was applied to a film, it was magnetically oriented before the paint was sufficiently dried and solidified. And then dried. Furthermore, this coated film was subjected to a surface treatment with a super calender,
A video tape was slit into a 2-inch width. This video tape was evaluated for the following magnetic tape characteristics at normal speed using an NV-3700 type video deck manufactured by Matsushita Electric Corporation.

(A) VTR head output The VTR head output at a measurement frequency of 4 MHz was measured by a synchroscope, the reference tape was set to 0.0 decibel (dB), and the relative value was determined based on the following criteria. . ：: +2 dB or more Δ: +0 dB to +2 dB ×: +0 dB or less (B) Skew A video tape on which a chroma video signal is recorded is played back.
Perform a delayed sweep operation on the Shiva-Soku Color Monitor CMM20-11, read the amount of distortion on the screen with a measure, convert it to one horizontal scanning time using the ratio of the entire width of the monitor screen, and convert the value expressed in μsec to the following standard. Judged. ：: 2 μsec or less Δ: 2 μsec to 5 μsec ×: 5 μsec or more

(8) Adhesive Strength of Magnetic Layer The adhesive strength of the magnetic layer was determined by measuring the above-mentioned video tape with a double-sided tape No. 665, using a tensile tester Intesco Model 2001 manufactured by Intesco Corporation,
In a room adjusted to a temperature of 23 ° C. and a humidity of 50% RH, the film was peeled 180 ° at a speed of 500 mm / min and judged according to the following criteria. ：: 30 gf or more Δ: 15 to 30 gf ×: 15 gf or less (9) Carboxyl value Pohl's method (Anal. Chem., 26, 161)
4 (1954)).

Example 1 (Production of polyethylene naphthalate) Naphthalene-2,
100 parts of dimethyl 6-dicarboxylate, 60 parts of ethylene glycol and 0.1 part of calcium acetate monohydrate were placed in a reactor, and a transesterification reaction was performed. That is, the reaction starting temperature was set to 180 ° C., and the reaction temperature was gradually increased with the distillation of methanol to reach 230 ° C. after 4 hours, thereby substantially terminating the transesterification reaction. Then phosphoric acid 0.0
After adding 4 parts, 0.04 part of antimony trioxide was added, and a polycondensation reaction was carried out by a conventional method. That is, the temperature was gradually increased and the pressure was gradually decreased. After 2 hours, the temperature was 290 ° C. and the pressure was 0.3 mmHg. After 4 hours from the start of the reaction, the reaction was stopped, and polyethylene naphthalate was discharged under nitrogen pressure. This molten polymer was directly connected to an extruder as it was, filtered with a filter, and then extracted in a strand shape and cut into chips to obtain a polymer raw material. The resulting polyethylene naphthalate polymer raw material had an intrinsic viscosity of 0.68 and a carboxyl group value of 80 equivalents / ton.

(Production of polyethylene naphthalate film) The obtained polyethylene naphthalate raw material was dried,
The sheet was extruded at 0 ° C. from an extruder into an amorphous sheet using an electrostatic application cooling method. The obtained amorphous sheet was first stretched 3.0 times at 135 ° C. in the machine direction. Subsequently, a water-soluble polyester comprising 92 mol% of terephthalic acid, 8 mol% of sodium sulfoisophthalic acid, 75 mol% of ethylene glycol, and 25 mol% of diethylene glycol (details below)
And serial of as) 90 parts, the average particle size 0.07μm divinylbenzene and spherical crosslinked polymethyl methacrylate particles comprising a copolymer of methyl methacrylate (Nippon catalyzed
An aqueous coating agent consisting of 10 parts of Gaku Kogyo Co., Ltd. and 1900 parts of water was applied to one surface and stretched 4.0 times at 140 ° C. in the horizontal direction. Further, the film is stretched 1.8 times again at 160 ° C., then stretched 1.3 times at 220 ° C. in the horizontal direction, heat-set at 230 ° C. while stretching, and relaxed by 4% in the vertical and horizontal directions upon cooling. Let the thickness of the coating layer be 0.06μ
m, biaxially oriented polyethylene having a film thickness of 4.5 μm
A 2,6-naphthalate film was obtained. The density of the obtained film was 1.375 g / cm ³ . The properties of the obtained film were as shown in Tables 1 to 3, and had excellent properties. ・ 80 parts of water-soluble polyester dimethyl terephthalate, 5-sodium sulfoiso
10 parts of dimethyl phthalate, 50 parts of ethylene glycol,
10 parts of diethylene glycol and 0.1 of calcium acetate
Parts, lithium acetate 0.3 parts, antimony trioxide 0.03
And transesterification according to the usual method.
0.05 parts of trimethyl acid were added. Then gradually rise
Reduce the temperature and pressure and finally compress at 280 ° C and 1mmHg or less.
The combined reaction was performed to obtain a water-dispersible polyester. Got
The composition of the polyester was measured by H-NMR.
As an acidic component, 92 mol% of terephthalic acid, 5-sodium
8 mol% of sulphoisophthalic acid, as a glycol component
75% by mole of ethylene glycol, diethylene glycol
Was 25 mol%.

Comparative Example 1 A film was obtained in the same manner as in Example 1 except that no coating layer was provided. The properties of the obtained film are as shown in Tables 1 to 3, and the workability was poor and the adhesiveness was poor, and the film was not practically usable. Comparative Example 2 A film was obtained in the same manner as in Example 1 except that a spherical silica sol having a particle size of 0.07 μm was used instead of the crosslinked polymethyl methacrylate particles. The properties of the obtained film are as shown in Tables 1 to 3, and the film generated a lot of white powder and had poor electromagnetic conversion characteristics.

Example 2 In the same manner as in Example 1, except that spherical crosslinked polystyrene particles having a particle size of 0.07 μm (Muticle manufactured by Mitsui Toatsu Co., Ltd.) were used instead of the crosslinked polymethyl methacrylate particles. A film was obtained. The properties of the obtained film were as shown in Tables 1 to 3, and had excellent properties. Example 3 A film was obtained in the same manner as in Example 1, except that the particle size of the crosslinked polymethyl methacrylate particles was 0.15 μm and the coating thickness was 0.10 μm. The properties of the obtained film were as shown in Tables 1 to 3, and had excellent properties.

Example 4 In Example 3, crosslinked polystyrene particles having a particle size of 0.12 μm were used instead of the crosslinked polymethyl methacrylate particles.
A film was obtained in the same manner as in Example 3 except that (Muticle manufactured by Mitsui Toatsu) was used. The properties of the obtained film were as shown in Tables 1 to 3, and had excellent properties. Comparative Example 3 A film was obtained in the same manner as in Example 1 except that the blending amount of the crosslinked polymethyl methacrylate particles in the coating composition of Example 1 was changed to 0.05 part. The properties of the obtained film are as shown in Tables 1 to 3, and the workability was poor and the film could not be put to practical use.

Example 5 A film was obtained in the same manner as in Example 1 except that the blending amount of the crosslinked polymethyl methacrylate particles in the coating composition of Example 1 was changed to 30 parts. The properties of the obtained film are 1-3
And had excellent characteristics. Comparative Example 4 A film was obtained in the same manner as in Example 1 except that the blending amount of the crosslinked polymethyl methacrylate particles in the coating composition of Example 1 was changed to 45 parts. Table 1 shows the properties of the obtained film.
As shown in FIG. 3, white powder was generated frequently and the film had poor electromagnetic conversion characteristics.

Comparative Example 5 A film was obtained in the same manner as in Example 1 except that the particle size of the crosslinked polymethyl methacrylate particles was changed to 1.1 μm. The properties of the obtained films are shown in Tables 1 to 3.
As shown in the figure, the film had poor electromagnetic conversion characteristics and generated a large amount of white powder, and could not be put to practical use. Example 6 As a coating liquid, 85 parts of water-dispersible polyester polyurethane AP-40 (manufactured by Dainippon Ink and Chemicals, Inc.), crosslinked polymethyl methacrylate 1 having an average particle size of 0.07 μm 1
A film was obtained in the same manner as in Example 1, except that an aqueous coating agent comprising 5 parts and 1900 parts of water was applied to one surface. The properties of the obtained film were as shown in Tables 1 to 3, and had excellent properties.

Comparative Example 6 A polyethylene terephthalate raw material obtained according to a conventional method was dried, extruded at 290 ° C. from an extruder into a sheet, and formed into an amorphous sheet by using an electrostatic application cooling method. The obtained amorphous sheet was stretched in the machine direction by 4.5 times at 90 ° C., followed by 92 mol% of terephthalic acid, 8 mol% of sodium sulfoisophthalic acid, 75 mol% of ethylene glycol and 25 mol% of diethylene glycol. 90 parts of polyester,
An aqueous coating agent consisting of 10 parts of spherical crosslinked polymethyl methacrylate particles composed of a copolymer of divinylbenzene and methyl methacrylate having an average particle size of 0.07 μm and 1900 parts of water was applied to one surface, and then applied horizontally at 100 ° C. .8
It was stretched twice. Further, the film is stretched 1.3 times again at 130 ° C., then stretched 1.1 times at 190 ° C. in the transverse direction, heat-set at 230 ° C. while stretching, and relaxed 4% in the machine and transverse directions upon cooling. Thus, a biaxially stretched polyethylene terephthalate film having a coating layer thickness of 0.06 μm and a film thickness of 4.5 μm was obtained. The properties of the obtained film are shown in Table 1.
As shown in Nos. 1 to 3, the film had poor skew characteristics and could not be put to practical use.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

The film of the present invention is a film having excellent mechanical strength and slipperiness and having abrasion resistance, and its industrial value is high.

Claims (1)

(57) [Claims] 1. Polyethylene-2,6 having a thickness of 9 μm or less.
A laminated film having a coating layer containing 0.5 to 40% by weight of organic particles on at least one side of a naphthalate film, and simultaneously satisfying the following formulas: 6-naphthalate film. F5 value in film longitudinal direction ≧ 1.5 × 10 ⁸ Pa ... Young's modulus in film longitudinal direction ≧ 5.9 × 10 ⁹ Pa… Young's modulus in film lateral direction ≧ 5.9 × 10 ⁹ Pa… Center line of coating layer Average surface roughness ≦ 0.020 μm ...