JP2008238648A - Film for transparent vapor deposition, and transparent vapor-deposited film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester film for transparent vapor-deposition capable of stably giving and markedly enhancing a gas barrier functionality and a damp-proofness with a thin vapor-deposition thickness, and to provide a transparent vapor-deposited polyester film. <P>SOLUTION: The polyester film for transparent vapor-deposition and the transparent vapor-deposited polyester film are biaxially-oriented polyester films wherein the center line surface roughness (SRa) of the film surface on the vapor-deposition side is 2 to 80 nm, the number of peaks (SPc) is 5 to 130 pieces/0.1 mm<SP>2</SP>, a polyester oligomer precipitating on the film surface on the vapor-deposition side after being left for 30 days at a room temperature of 30°C and having a diameter of not less than 0.5 μm is not more than 1,500 pieces/mm<SP>2</SP>, a fusion sub-peak Ts of the film is 190 to 235°C, the content of diethylene glycol in the film is not more than 2.0 wt.%, and the films are 5 to 100 μm thick. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

    The present invention relates to a film for transparent vapor deposition. More specifically, the present invention relates to a biaxially oriented polyester film for transparent vapor deposition having a gas barrier property and moisture resistance by providing a transparent vapor deposition layer, and the transparent vapor deposited polyester film.

    Conventionally, biaxially oriented polyester films are excellent in transparency, mechanical properties, moisture resistance and the like, and are widely used for packaging materials and the like. Furthermore, for the purpose of improving the gas barrier property while maintaining the transparency of the film, a biaxially oriented polyester film coated with polyvinylidene chloride is a film having an excellent gas barrier property and is widely known as K-PET. However, polyvinylidene chloride has insufficient moisture resistance and cannot be used for moisture-proof packaging. In addition, polyvinylidene chloride generates chlorine-based gas during incineration, and it has been pointed out that corrosion of the incinerator and adverse effects on the global environment have been pointed out. Furthermore, the equipment investment burden on the incinerator for purifying exhaust gas is also large. ing. As a countermeasure against the chlorine gas problem, a film in which an ethylene vinyl alcohol copolymer is laminated is known. However, the gas barrier property and moisture proof property are insufficient, and it is remarkably lowered particularly in sterilization treatment at a high temperature. As a packaging film for solving these problems, it has been well known that metal aluminum is formed on a polyester film or metal oxide is formed on a polyester film and has excellent gas barrier properties and moisture resistance. Yes. However, metal aluminum requires a thick film to ensure high gas barrier properties and moisture resistance, resulting in decreased productivity. Moreover, when packaged, there are problems that the contents cannot be seen, the metal detector cannot be used to check the package contents, and the microwave oven cannot be heated without packaging through the microwave.

A packaging film in which a metal oxide is vapor-deposited solves such a problem of metal aluminum. In particular, a film in which a silicon oxide film is formed on a polyester film is disclosed in Patent Document 1 and an aluminum oxide film is formed on a polyester film. It is known from US Pat.
JP-A-6-278240 Japanese Patent Laid-Open No. 11-10725

  In recent years, as various foods and confectionery appear on the market, the improvement of characteristics such as barrier properties and the long-term preservation of quality have become more important. Particularly in the packaging of snacks and foods, the gas barrier property is required to be higher than before in order to prevent the contents from being oxidized and moistened and to ensure the quality over a longer period of time.

    In addition, the production of such a transparent vapor-deposited polyester film has become highly demanded for polyester film in order to stabilize gas barrier performance by improving the productivity, increasing the size and speed of the equipment, and making the vapor deposition thin film accordingly.

  The present invention aims to solve the above-described problems. That is, this invention provides the polyester film for transparent vapor deposition which improves the outstanding gas barrier property and moisture-proof property markedly.

    As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a polyester film having specific physical properties as a base material.

That is, the gist of the present invention is as follows.
(1) A biaxially oriented polyester film,
The center line surface roughness (SRa) of the deposition side film surface is 2 to 80 nm,
The number of peaks (SPc) is 5 to 130 / 0.1 mm ² ,
After standing at 30 ° C. for 30 days, 1500 oligomers / mm ² or less of polyester oligomers having a diameter of 0.5 μm or more present on the vapor deposition side film surface,
Film melting sub-peak Ts is 190 to 235 ° C.,
A polyester film for transparent vapor deposition having a thickness of 5 to 100 μm, wherein the amount of diethylene glycol in the film is 2.0% by weight or less,
(2) The polyester film for transparent vapor deposition according to (1), wherein the thermal shrinkage rate at 190 ° C. for 20 minutes is 1.0 to 6.0% in the length direction and 0 to 6.0% in the width direction,
(3) The polyester film for transparent deposition according to any one of claims 1 and 2, wherein the deposition side film surface has a wetting tension of 45 mN / m or more.

(4) A transparent vapor-deposited polyester film comprising a transparent vapor-deposited layer on at least one surface of the transparent vapor-deposited polyester film according to any one of (1) to (3),
(5) The transparent vapor deposition polyester film whose transparent vapor deposition layer as described in (4) is a layer which uses aluminum oxide,
(6) The transparent vapor deposition polyester film whose transparent vapor deposition layer as described in (4) is a layer which uses a silicon oxide,
(7) The transparent vapor deposition polyester film whose transparent vapor deposition layer as described in (4) is a layer which uses aluminum oxide and silicon oxide,
It is.

  The polyester film for transparent vapor deposition of the present invention has an effect of stably imparting high gas barrier performance and moisture proof performance with a thin vapor deposition film thickness.

  Moreover, the transparent vapor-deposited polyester film of the present invention can be used as a single packaging film, but further, printing, coating a protective layer or the like on the vapor-deposited film, laminating a heat seal layer, It can also be used by further processing such as laminating with other films or combining them. Moreover, a heat seal layer can be laminated on the non-deposited surface, laminated with another film, or a combination thereof.

   The present invention will be described in detail. The polyester film of the present invention is a biaxially oriented polyester film, which is produced by stretching a non-stretched polyester sheet or film in a so-called biaxial direction in the longitudinal direction and the width direction, and wide-angle X-ray diffraction. And a pattern showing a biaxial orientation pattern. As the method of stretching in the biaxial direction, either the sequential biaxial stretching method or the simultaneous biaxial stretching method can be used, but the simultaneous biaxial stretching method is preferable because scratches on the film surface are less likely to occur.

    The polyester used in the polyester film of the present invention is a polyester comprising dibasic acid and glycol as constituent components, and examples of the aromatic dibasic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, diphenylsulfone. Dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, cyclohexane dicarboxylic acid, diphenyl ketone dicarboxylic acid, phenylindane dicarboxylic acid, sodium sulfoisophthalic acid, dibromoterephthalic acid and the like can be used. As the alicyclic dibasic acid, cyclohexane dicarboxylic acid, decalin dicarboxylic acid, hexahydroterephthalic acid, or the like can be used. As the aliphatic dibasic acid, oxalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid and the like can be used. As the glycol, ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol and the like can be used as the aliphatic diol, and naphthalenediol, 2,2-bis (4-hydroxydiphenyl) as the aromatic diol. ) Propane, 2,2-bis (4-hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, hydroquinone, tetraprobisbisphenol A and the like, and as the alicyclic diol, cyclohexanedimethanol, Cyclohexanediol and the like can be used.

    Further, a polyfunctional compound having three or more functional groups within the range in which the polyester is substantially linear, such as glycerin, trimethylolpropane, pentaerythritol, trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid, gallic acid, etc. May be copolymerized, or a monofunctional compound such as o-benzoylbenzoic acid or naphthoic acid may be added and reacted. Further, polyethers such as polyethylene glycol and polytetramethylene glycol, and aliphatic polyesters typified by polycaprolactone may be copolymerized.

  Two or more kinds of polyesters may be blended. For example, if the total amount of blended materials is 100% by weight and 50% by weight or more is polyester, other than polyester may be blended.

    It is desirable that the polyester has a melting point of 240 ° C. or higher and 280 ° C. or lower from the viewpoint of heat resistance and film forming property.

    In addition, known additives such as heat stabilizers, oxidation stabilizers, weathering stabilizers, UV absorbers, organic lubricants, pigments, dyes, fillers, antistatic agents, nuclei An agent or the like may be blended. The intrinsic viscosity (measured in an orthochlorophenol at 25 ° C.) of the polyester resin as described above is preferably 0.40 to 1.20, more preferably 0.50 to 0.80, and still more preferably 0. The range is from 55 to 0.75 dl / g.

  The particles contained in the polyester film of the present invention include particles, aggregates, silicon dioxide particles, calcium carbonate particles, alumina particles, titanium oxide particles, barium sulfate particles, aluminum silicate particles, calcium phosphate produced during polymerization with various nucleating agents. Typical examples thereof include inorganic particles such as particles, mica, kaolin, and clay, organic particles such as crosslinked polystyrene particles, acrylic particles, imide particles, and silicone particles, or mixtures thereof. . Of these, inorganic particles such as silicon dioxide particles, calcium carbonate particles, alumina particles, and aluminum silicate particles, or a mixture of these inorganic particles and particles produced during polymerization using various nucleating agents are preferable. These particles can also be used in various shapes such as spherical particles, agglomerated particles, scaly particles, and beaded particles.

  The diameter of various particles used is not particularly limited, but is usually measured by a sedimentation method or a light scattering method. In the particle size measurement of the present invention, the resin is ashed but the particles are not damaged, and the resin is removed from the film by plasma low-temperature ashing to expose the particles. Then, about 100 particles are observed, and the particle diameter of the particle image is obtained from the equivalent circle diameter by an image processing apparatus. In the case of particles produced by polymerization with various nucleating agents, the polymer cross section is cut to prepare ultrathin sections having a thickness of about 0.1 to 1 μm, and photographs are taken at a magnification of about 10,000 using a transmission electron microscope (10 sheets: 25 cm × 25 cm), and the average dispersion diameter of the internal particles is calculated from the equivalent circle diameter. A number average particle diameter of 0.05-8.0 micrometers, Preferably it is 0.1-6.0 micrometers, More preferably, 1.0-5.0 micrometers can be mentioned as an average particle diameter of a preferable particle | grain. The content of such particles is preferably 0.01 to 10% by weight, more preferably 0.01 to 1% by weight, and more preferably 0.01 to 0.5% by weight with respect to the polyester film.

  The polyester film of the present invention is preferably a polyester film using a resin having a —COOH amount of 25 to 55 equivalent / t. Antimony trioxide is added as a catalyst so that the Sb content is 150 to 650 ppm in PET, and the amount of COOH in the resin is adjusted to 25 to 55 equivalent / t. When the amount of —COOH of the resin is less than 25 equivalent / t, the gas barrier property and moisture resistance of the vapor-deposited biaxially oriented polyester film cannot be sufficiently exhibited. If the -COOH amount of the resin exceeds 55 equivalents / t, the appearance of the polyester film is colored, and in the case of a transparent vapor-deposited polyester film, there is a problem that the transparency is deteriorated or the film forming property of the polyester film is deteriorated. . The amount of —COOH was measured by placing the film before vapor deposition in o-cresol, heating and dissolving at 100 ° C. with stirring, cooling to room temperature, and titrating with an N / 50 alkaline solution.

  The thickness of the polyester film of the present invention is 5 to 100 μm, and preferably 5 to 25 μm. Among these, a suitable range may be arbitrarily selected depending on the application.

  The film structure may be a single layer or a laminated structure composed of polyester compositions A, B, and C having different compositions, for example, a two-layer structure of A / B, A / B / A, or A / B. A three-layer structure of / C may be used, and a multilayer structure having a multilayer structure larger than three layers may be used. The lamination thickness ratio at that time may also be set arbitrarily. These laminated structures can be manufactured as a laminated film by coextrusion.

  In the polyester film of the present invention, the amount of diethylene glycol in the film is 2.0% by weight or less. Preferably, it is 1.5% by weight or less, more preferably 1.0% by weight or less, more preferably 0.9% by weight or less, particularly preferably 0.8% by weight or less, and further preferably 0.7% by weight or less. It is. When diethylene glycol in the film exceeds 2.0% by weight, gas barrier performance and moisture resistance are often lowered. In addition, the polyester film is subjected to a vapor deposition step, and further subjected to printing, adhesive coating, or laminating processing, all of which receive a thermal history. If the content of diethylene glycol in the film exceeds 2.0% by weight, the heat resistance of the film will drop and the film will be stretched against the external force or wrinkled in each processing step, making the film run unstable. Thus, there arises a problem that workability is deteriorated. If the DEG is 0.01% by weight or less, the film productivity may become unstable, such as tearing.

  In the case of polyethylene terephthalate, diethylene glycol in the film is produced as a side reaction in the pellet manufacturing process. The amount of diethylene glycol at this time can be adjusted by controlling the amount of polymerization catalyst, the method of adding ethylene glycol and the reaction temperature, and the amount of alkali compound added as a transesterification catalyst.

In the polyester film of the present invention, after standing at 30 ° C. for 30 days, the number of polyester oligomers having a diameter of 0.5 μm or more present on the vapor deposition side film surface is 1500 pieces / mm ² or less. The number is preferably 1300 pieces / mm ² or less, more preferably 1000 pieces / mm ² or less, more preferably 800 pieces / mm ² or less, and still more preferably 500 pieces / mm ² or less. When an oligomer is present on the film deposition surface, the formation of a transparent deposition film is hindered during the deposition, causing defects. If the number of polyester oligomers with a diameter of 0.5 μm or more present on the vapor deposition side film surface exceeds 1500 / mm ² , storing the film for 30 days or more at high temperatures such as in the summer after production will provide gas barrier performance and moisture resistance. descend.

The polyester oligomer deposited on the surface of the vapor deposition side film of the present invention is the number of polyester oligomers having a diameter of 0.5 μm or more deposited per unit film area after standing at room temperature for 30 days for 30 days. After leaving at 30 ° C. for 30 days, aluminum is vacuum-deposited on the transparent deposition surface side, a photograph is taken at a magnification of 1000 times with a differential interference microscope, and the number of precipitated polyester oligomers having a diameter of 0.5 μm or more is counted and converted to 1 mm ² . The diameter of the oligomer is the average value of the major axis and minor axis. In order to reduce the number of polyester oligomers having a diameter of 0.5 μm or more deposited on the vapor deposition side film surface after standing at 30 ° C. for 30 days to 1500 pieces / mm ² or less, polyester pellets with a small amount of oligomers can be used, For example, the heat treatment temperature during film formation may be lowered, or the film oligomer after film formation may be washed and extracted with a solvent.

  The polyester film of the present invention has a film melting subpeak Ts of 190 to 235 ° C. Preferably, it is 195-230 degreeC, More preferably, it is 195-225 degreeC, More preferably, it is 195-220 degreeC. When Ts exceeds 235 ° C., gas barrier performance and moisture resistance are deteriorated. In addition, the film becomes brittle. When Ts is less than 190 ° C., the adhesion between the film and the transparent vapor-deposited layer deteriorates, and delamination occurs after printing or laminating. In addition, the thermal dimensional stability at high temperatures deteriorates, and problems such as printing pitch misalignment occur after processing.

  The melting subpeak of the film is a minute endothermic peak that appears before crystal melting by differential scanning calorimetry. This melting sub-peak Ts is observed as a minute peak at the temperature corresponding to the heat treatment temperature of the film (it may be a ladder peak if it overlaps with the melting endothermic curve of the film) and is incomplete in the crystal structure formed by the heat treatment. This is because a large portion (pseudocrystal) melts.

  Therefore, in order to set the melting subpeak Ts of the film to 190 to 235 ° C., it is possible to set the heat treatment temperature during film formation within this range.

  The polyester film of the present invention preferably has a heat shrinkage rate of 190 ° C. and 20 minutes of 1.0 to 6.0% in the length direction and 0 to 6.0% in the width direction. In the length direction, it is preferably 1.0 to 5.5%, more preferably 1.5 to 5.0%. In the width direction, it is preferably 0.5 to 5.5%, more preferably 1.0 to 5.0%. The polyester film is subjected to a vapor deposition process, and is further subjected to printing, adhesive coating, or laminating processing. When the heat shrinkage rate in the length direction is less than 1.0% or the heat shrinkage rate in the width direction is less than 0%, the gas barrier performance and moisture resistance are lowered. In addition, wrinkles are generated in the film in each processing step, and the running property of the film becomes unstable, resulting in deterioration of workability. When the thermal shrinkage in the length direction exceeds 6.0% or the thermal shrinkage in the width direction exceeds 6.0%, the thermal dimensional stability at high temperatures deteriorates, and the printing pitch shift after processing or each processing Wrinkles occur in the film during the process. The range of the heat shrinkage rate can be adjusted by performing a relaxation treatment with a heat treatment temperature range of 190 to 235 ° C. and 0 to 12% in the width direction.

The polyester film of the present invention has a center line surface roughness (SRa) of 2 to 80 nm and a peak number (SPc) of 5 to 130 / 0.1 mm ² on the vapor deposition side film surface. The center line surface roughness (SRa) is preferably 5 to 60 nm, more preferably 10 to 50 nm. Here, SRa is a parameter of the three-dimensional surface roughness and is defined as the center plane average roughness. If SRa is less than 2 nm, slipping may be deteriorated and the film cannot be wound into a roll or may be blocked. On the other hand, if SRa exceeds 80 nm, the gas barrier property and moisture resistance after vapor deposition deteriorate. Here, SRa is a parameter of the three-dimensional surface roughness and is defined as the centerline plane average roughness. The number of peaks (SPc) is preferably 5 to 120 pieces / 0.1 mm ² , more preferably 10 to 100 pieces / 0.1 mm ² . If the number of peaks (SPc) is less than 2 pieces / 0.1 mm ² , the slippage is poor, and there is a problem that the film cannot be wound into a roll or blocking, and the number of peaks (SPc) is 130 pieces. If it exceeds /0.1 mm ² , gas barrier properties and moisture resistance after vapor deposition deteriorate. SRa and SPc can adjust the ranges of SRa and SRz by adding 0.01 to 0.50% by weight of particles having an average particle size of 1.0 to 5.0 μm in the raw material pellets.

  Centerline surface roughness (SRa) and number of peaks (SPc) are three-dimensional roughness parameters of a three-dimensional roughness meter manufactured by Kosaka Laboratory. The center line surface roughness (SRa) is obtained by placing orthogonal coordinates X and Y axes on the center surface of the roughness curved surface and setting the axis orthogonal to the center surface as the Z axis, the roughness curved surface as f (x, y), and the reference surface. Are the values given by Equation 1 below.

  The number of peaks (SPc) is expressed by converting the number of peaks recognized as peaks on both the upper and lower planes by providing planes parallel to the center plane of the roughness curved surface and measuring the number of peaks on both the upper and lower planes.

  The center line surface roughness (SRa) and the number of peaks (SPc) can be determined by the content of the particles in the polyester film.

  The polyester film of the present invention has a wetting tension of 45 mN / m or more on the vapor deposition side film surface based on JIS K-6768-1995. Preferably it is 48 mN / m or more, more preferably 50 mN / m or more. If the wetting tension is less than 45 mN / m, the gas barrier property and moisture resistance after vapor deposition cannot be sufficiently exhibited, or the adhesion between the vapor deposition layer and the polyester film is insufficient, such as lamination onto the vapor deposition layer of the polyester film. When post-processing is performed, there is a problem that the deposited layer and the polyester film are peeled off. As a method for controlling the wetting tension within the above range, typically, corona discharge treatment can be used.

  The transparent vapor deposition layer provided on the transparent vapor deposition polyester film of the present invention is aluminum oxide, silicon oxide, or a mixed layer of aluminum oxide and silicon oxide. Among them, an aluminum oxide film is advantageous in view of food hygiene, cost, production facilities, and coloring.

  The thickness of the transparent vapor deposition layer of the transparent vapor deposition polyester film of this invention is 1-40 nm, Preferably it is 2-30 nm. If it is less than 1 nm, gas barrier property and moisture-proof property will deteriorate. If it exceeds 40 nm, productivity will fall. In particular, in the case of a metal oxide, if the film thickness is increased, the film tends to curl, and if it is handled poorly, it will crack and the gas barrier properties and moisture resistance will deteriorate, and the deposited film will be colored. Or

  Next, although the typical manufacturing method of the polyester film for transparent vapor deposition of this invention is demonstrated, it does not specifically limit to this.

  Resin containing inorganic particles or organic particles in which the amount of DEG or -COOH is adjusted in the transesterification reaction or polymerization stage, or the amount of oligomer is adjusted by solid-phase polymerization (a biaxially oriented polyester film should be constructed) The resin is dried under predetermined conditions, melted with an extruder or the like, and then formed into a film (usually on a cooling drum). In order to improve the adhesion between the film-like material and the cooling drum, it is usually preferable to employ an electrostatic application adhesion method and / or a liquid surface application adhesion method. This film is heated to 75 to 130 ° C. and stretched 2.0 to 9.0 times in the longitudinal direction to form a uniaxially oriented film. When a coating layer is provided on a non-deposition surface by film formation, a surface treatment such as a corona discharge treatment is appropriately applied to the non-deposition surface of the uniaxially oriented film as necessary, and an aqueous resin is then added to a known method (gravure coater). , Reverse coater, kiss coater, die coater, bar coater, comma coater, etc.). While this uniaxially oriented film is heated to 75 to 130 ° C., it is stretched 2.0 to 9.0 times in the width direction, and subsequently introduced into a heat treatment zone of 190 to 235 ° C. and heat treated for 1 to 10 seconds. . During this heat treatment, it is better to perform a relaxation treatment of 0 to 12% in the width direction. The heat-treated film was gradually cooled through an intermediate cooling zone, and when it reached room temperature, it was used as a winding mill roll with a winder. Next, this mill roll was subjected to a slitter to obtain a product roll. The corona discharge treatment was performed on the vapor deposition surface side surface of the film while the product roll was rewound. When the corona discharge treatment is performed on the non-deposition surface side, it is performed at the time of rewinding.

  The amount of DEG is adjusted by adding antimony trioxide as a catalyst so that the Sb content is 150 to 650 ppm in PET, or by adding an alkali metal compound such as a manganese compound or potassium.

  A vapor-deposited layer is provided on the biaxially oriented polyester film thus obtained. To deposit aluminum oxide in reactive vapor deposition, aluminum metal and alumina are evaporated by resistance heating boat method, high frequency induction heating of crucible, electron beam heating method, and oxidized on biaxially oriented polyester film under oxidizing atmosphere. A method of depositing aluminum is adopted. As a reactive gas for forming an oxidizing atmosphere, water or a rare gas may be added mainly with oxygen. Further, ozone may be added or a method for promoting a reaction such as ion assist may be employed. It is more preferable to use a plasma treatment of the biaxially oriented polyester film surface in these vacuum processes because gas barrier properties and moisture permeability are improved.

In order to deposit silicon oxide by reactive evaporation, Si metal, SiO or SiO ₂ is evaporated by an electron beam heating method, and silicon oxide is deposited on a biaxially oriented polyester film in an oxidizing atmosphere, or organic silicon. A plasma chemical vapor deposition method is employed in which silicon oxide is deposited on a biaxially oriented polyester film in a compound gas, oxygen gas and inert gas. The method described above is used as a method of forming the oxidizing atmosphere.

  The reactive vapor deposition method described above is also used to deposit a mixed layer of aluminum oxide and silicon oxide.

[Measurement method of characteristic values]
(1) Surface oligomer measurement A 10 cm × 10 cm sample taken from a product roll before vapor deposition immediately after film formation is placed in an oven set at 30 ° C. and left for 30 days. After standing, converted to count and 1 mm ² per the number of polyester oligomer precipitated diameter of at least 0.5μm take pictures at a magnification 1,000 times under a differential interference microscope by vacuum depositing aluminum on the film surface of the vapor deposition side extraction to room temperature of the room did. The diameter of the oligomer was determined from the average value of the major axis and the minor axis.

(2) Film melting sub-peak Ts
The film collected from the product roll before vapor deposition was measured with a differential scanning calorimeter (DSC-2 manufactured by Perkin Elmer Co.) at a heating rate of 20 ° C./min. The sub-peak temperature generated by the transformation of the pseudo crystal observed by this measurement was defined as Ts.

(3) Diethylene glycol in polyester Content of film component collected from product roll before vapor deposition was measured by ¹³ C-NMR spectrum.

(4) Heat shrinkage rate The film sample taken from the product roll before vapor deposition has a marked interval of 200 mm, the film is cut to a width of 10 mm, the film sample is suspended in the length direction, and a 1 g load is applied in the length direction. After heating for a predetermined time using a hot air oven set at a predetermined temperature in advance, the length between the marked lines was measured, and the amount of film shrinkage was expressed as a percentage of the original dimension.

(5) Centerline surface roughness (SRa), number of peaks (SPc)
Using a three-dimensional surface roughness meter (manufactured by Kosaka Laboratory, ET-30HK), the film surface collected from the product roll before vapor deposition was measured by the stylus method under the following conditions.

Needle diameter 2 (μmR)
Needle pressure 10 (mg)
Measurement length 500 (μm)
Vertical magnification 20000 (times)
CUT OFF 250 (μm)
Measurement speed 100 (μm / s)
Measurement interval 5 (μm)
Number of recordings 80 Hysteresis width ± 5 (nm)
Reference area 0.1 (mm ² ).

(6) Wetting tension According to the method described in JIS K-6768-1995, the wetting tension of the film surface was measured on the surface on the vapor deposition side of the film collected from the product roll after the corona discharge treatment before vapor deposition.

(7) Carboxyl end group amount (COOH)
The film collected from the product roll before vapor deposition was placed in o-cresol, dissolved by heating at 100 ° C. with stirring, cooled to room temperature, and titrated with an N / 50 alkaline solution. The carboxyl end group amount (COOH) was calculated from the titration amount by the following formula.

A = Sample titration (ml)
B = Blank titration (ml) (solvent titration)
W = Sample weight (g)
COOH (equivalent / ton) = ((A−B) × 1/50 × 10 ³ ) / W
(8) Film thickness of vapor deposition layer The film after transparent vapor deposition was extract | collected, and the cross section was observed by the ultrathin section method with the acceleration voltage of 100 kV using the transmission electron microscope (the JEOL Co., Ltd. make, JEM-1200EX), The film thickness of the deposited film was measured.

(9) Gas barrier properties Water vapor permeability One week after vapor deposition, a transparent vapor deposition film was collected, and a water vapor permeability meter Permatran W 3/31 manufactured by Modern Control Co. was used according to method B described in JIS K-7129-1992, and a condition of 40 ° C. and 90 RH%. Measured with The water vapor permeability measured was evaluated as follows.
A: 0 (g / m ² · day) or more, less than 2 (g / m ² · day) ○: 2 (g / m ² · day) or more, less than 4 (g / m ² · day) ×: 4 ( g / m ² · day) or more.

B. Oxygen permeability One week after vapor deposition, a transparent vapor-deposited film was collected, and the oxygen permeability measurement apparatus OX-TRAN 2/20 manufactured by Modern Control Co. was used according to the method B described in JIS-K-7126-1987. The oxygen transmission rate was measured under the condition of% RH. The measured oxygen permeability was evaluated as follows.
: 0 (cc / m ² · day) or more, less than 2 (cc / m ² · day) ○: 2 (cc / m ² · day) or more, less than 4 (cc / m ² · day) ×: 4 ( cc / m ² · day) or more.

(10) Workability The handling property of the film at the time of vapor deposition, coating, printing, and laminating was judged by ○ ×. If wrinkles or scratches on the roll due to unwinding or transporting of the film during processing, wrinkles between the rolls or between rolls, film fluttering, slipperiness, etc. occur, these problems If it does not occur, it is good and ◯.

Example 1
The esterification reaction was carried out with 86.4 parts by weight of terephthalic acid and 42 parts by weight of ethylene glycol, and 0.01 parts by weight of phosphoric acid and antimony trioxide were added so that the Sb content was 550 ppm in PET. Add 1.0 part by weight of ethylene glycol slurry adjusted to 0.15% by weight of agglomerated silica particles with a particle size of 1.5 μm, and then continue polycondensation reaction as usual under high temperature and high vacuum. A PET having an intrinsic viscosity of 0.63 dl / g and a diethylene glycol amount of 1.0% by weight was obtained. The PET pellets containing -COOH content of 35 equivalents / t containing 0.15% by weight of the agglomerated silica particles having an average particle size of about 1.5 µm were vacuum-dried to a moisture content of 20 ppm, and then supplied to an extruder at 280 ° C. After melt extrusion and filtration through a 10 μm cut filter, the sheet was extruded from a T-shaped die into a sheet shape, and this was cooled and solidified on a cooling drum having a surface temperature of 50 ° C. by an electrostatic application adhesion method. The unstretched PET film thus obtained was heated to 95 ° C. and stretched 3.5 times in the longitudinal direction to obtain a uniaxially stretched film. This uniaxially stretched film was preheated at 98 ° C. and then stretched 3.9 times in the width direction while being heated to 105 ° C. This film is introduced into hot air at 225 ° C., and fixed with tension heat for 1 second, and then cooled by applying 8% relaxation of the original film width in the width direction within the same atmospheric temperature. Finally it cooled to room temperature, this was led to the winder, it wound up, and it was set as the mill roll. Next, this mill roll was subjected to a slitter to obtain a product roll. While the product roll was rewound, corona discharge treatment was performed on each side of the film at a treatment strength of 20 W · min / m ² . Aluminum oxide was deposited on the 12 μm film thus obtained. In the method of depositing aluminum oxide on the surface of the biaxially oriented polyester film, the film is set on the unwinding device of a continuous vacuum vapor deposition machine and travels through a cooling metal drum to wind the film. At this time, the pressure of the continuous vacuum evaporator is reduced to 10 ⁻⁴ Torr or less, and the aluminum crucible is charged into the alumina crucible from the lower part of the cooling drum to heat and evaporate the metal aluminum, and oxygen is contained in the vapor. Was deposited and deposited on the film while oxidizing to form an aluminum oxide film having a thickness of 20 nm. Table 1 shows the characteristics of this transparent vapor-deposited biaxially oriented polyester film.

(Example 2)
In Example 1, the tension heat fixation temperature was changed to 230 ° C.

(Example 3)
In Example 1, antimony trioxide with an Sb content of 320 ppm in PET, film width relaxation of 5%, tension heat fixation temperature of 215 ° C., and PET pellets into PET pellets of 0.8% by weight of diethylene glycol. changed.

Example 4
In Example 1, antimony trioxide with an Sb content was changed to 150 ppm in PET, the relaxation of the film width was changed to 5%, and the tension heat fixing temperature was changed to 215 ° C. Further, after the PET pellets were subjected to condensation polymerization, solid layer polymerization was further performed to obtain an intrinsic viscosity of 0.72 dl / g, and the PET pellets were changed to 0.6% by weight of diethylene glycol.

(Example 5)
In Example 1, the tension heat fixation temperature was changed to 233 ° C.

(Example 6)
In Example 1, the tension heat fixation temperature was changed to 230 ° C. Further, the product roll subjected to the slitter was wound up, and the oligomer of the film was washed, extracted, dried and wound up through methylene chloride, and then subjected to corona discharge treatment. As in Example 1, this product roll was formed by depositing an aluminum oxide film having a thickness of 20 nm. The sample for measuring the surface oligomer was collected after the corona discharge treatment described above.

(Example 7)
In Example 1, the ethylene glycol slurry was changed to an ethylene glycol slurry in which aggregated silica particles having an average particle size of 1.5 μm were adjusted to 0.13% by weight in PET. In addition, the vapor deposition film of aluminum oxide was changed, and SiO and SiO ₂ were heated and evaporated on the film surface after corona discharge treatment in a vacuum of 3 × 10 ⁻⁵ Torr by a 10 kw electron beam heating method. A silicon oxide film having a thickness of 20 nm was formed.

(Example 8)
In Example 1, the ethylene glycol slurry was changed to an ethylene glycol slurry adjusted so that the aggregated silica particles having an average particle size of 1.5 μm were 0.13% by weight in PET. Moreover, the aluminum oxide vapor deposition film was changed, and a 3: 7 mixture of Al ₂ O ₃ and SiO ₂ was applied to the film surface after the corona discharge treatment in a vacuum of 10 ⁻⁴ Torr or less by an electron beam heating method of 10 kw. The film was evaporated by heating to form a transparent deposited film having a thickness of 30 nm on one side of the film.

Example 9
In Example 1, after the PET pellet was subjected to condensation polymerization, it was changed to a PET pellet having an intrinsic viscosity of 0.72 dl / g, which was further solid-phase polymerized.

(Example 10)
In Example 1, antimony trioxide was changed to PET pellets having an Sb content of 320 ppm in PET and PET pellets having a diethylene glycol amount of 0.8 wt%.

(Example 11)
In Example 1, ethylene was prepared by adjusting antimony trioxide to 320 ppm in PET with an Sb content and ethylene glycol slurry so that aggregated silica particles having an average particle size of 1.5 μm were 0.10 wt% in PET. In the glycol slurry, the PET pellets were changed to PET pellets having a diethylene glycol content of 0.8% by weight.

(Example 12)
In Example 1, antimony trioxide with an Sb content of 320 ppm in PET, ethylene glycol slurry with 0.10% by weight of monocylic silica particles having an average particle size of 1.5 μm in PET, and PET pellets with diethylene glycol The amount was changed to 0.8% by weight of PET pellets.

(Example 13)
In Example 1, 101 parts by weight of dimethyl terephthalate, 42 parts by weight of ethylene glycol, manganese acetate tetrahydrate and potassium acetate were added so that the Mn content in PET was 45 ppm and the K content was 20 ppm, and the ester exchange reaction was performed. Thereafter, 0.01 part by weight of phosphoric acid and antimony trioxide were added so that the Sb content was 240 ppm in the PET, and the aggregated silica particles having an average particle diameter of 1.5 μm were 0.15% by weight in the PET. 1.0 part by weight of ethylene glycol slurry adjusted so as to be added, and subsequently subjected to a polycondensation reaction in a conventional manner under high temperature and high vacuum, PET pellets having an intrinsic viscosity of 0.63 dl / g and a diethylene glycol amount of 0.2% by weight Changed to

(Example 14)
In Example 1, the ethylene glycol slurry was changed to an ethylene glycol slurry in which aggregated silica particles having an average particle size of 1.5 μm were adjusted to 0.01% by weight in PET.

(Example 15)
In Example 1, the ethylene glycol slurry was changed to an ethylene glycol slurry in which aggregated silica particles having an average particle size of 4.0 μm were adjusted to 0.10 wt% in PET.

(Example 16)
In Example 1, the ethylene glycol slurry was changed to be adjusted so that aggregated silica particles having an average particle size of 2.5 μm were 0.01% by weight in PET.

(Example 17)
In Example 1, the ethylene glycol slurry prepared by adjusting the ethylene glycol slurry so that aggregated silica particles having an average particle size of 1.5 μm were 0.21% by weight in PET was changed to 1.0 part by weight.

(Example 18)
In Example 1, antimony trioxide was changed to 750 ppm in PET with Sb content, PET pellets were changed to PET pellets having a diethylene glycol content of 1.9% by weight, and the tension heat setting temperature was changed to 194 ° C.

(Comparative Example 1)
In Example 1, the tension heat fixation temperature was changed to 2400C.

(Comparative Example 2)
In Example 1, antimony trioxide was changed to 800 ppm in PET with Sb content, and PET pellets were changed to PET pellets having a diethylene glycol content of 2.3 wt%.

(Comparative Example 3)
In Example 1, antimony trioxide was changed to PET pellets having an Sb content of 650 ppm in PET, a tension heat fixation temperature of 180 ° C., and PET pellets having a diethylene glycol content of 1.2% by weight.

(Comparative Example 4)
In Example 1, the ethylene glycol slurry was changed to an ethylene glycol slurry adjusted so that aggregated silica particles having an average particle size of 1.5 μm were 0.38 wt% in PET.

(Comparative Example 5)
In Example 1, the ethylene glycol slurry was adjusted so that the agglomerated silica particles having an average particle diameter of 4.1 μm were 0.25 wt% in the PET, and the agglomerated silica having a particle diameter of about 4.1 μm was added. The particles were changed to 0.25% by weight.

(Comparative Example 6)
In Example 1, antimony trioxide was changed to PET pellets having an Sb content of 650 ppm in PET, a tension heat fixation temperature of 233 ° C., and PET pellets of 1.2% by weight of diethylene glycol.
Table 1 shows the results of measurement and evaluation in each example and comparative example.

Claims (7)

A biaxially oriented polyester film,
The center line surface roughness (SRa) of the deposition side film surface is 2 to 80 nm,
The number of peaks (SPc) is 5 to 130 / 0.1 mm ² ,
After standing at 30 ° C. for 30 days, 1500 oligomers / mm ² or less of polyester oligomers having a diameter of 0.5 μm or more present on the vapor deposition side film surface,
Film melting sub-peak Ts is 190 to 235 ° C.,
A polyester film for transparent vapor deposition having a thickness of 5 to 100 μm, wherein the amount of diethylene glycol in the film is 2.0% by weight or less. 2. The polyester film for transparent vapor deposition according to claim 1, wherein the thermal shrinkage rate at 190 ° C. for 20 minutes is 1.0 to 6.0% in the length direction and 0 to 6.0% in the width direction. The polyester film for transparent vapor deposition according to claim 1 or 2, wherein the wet tension of the vapor deposition side film surface is 45 mN / m or more. The transparent vapor deposition polyester film which provides a transparent vapor deposition layer in the at least single side | surface of the polyester film for transparent vapor deposition in any one of Claims 1-3. The transparent vapor deposition polyester film whose transparent vapor deposition layer of Claim 4 is a layer which uses an aluminum oxide. The transparent vapor deposition polyester film whose transparent vapor deposition layer of Claim 4 is a layer which uses a silicon oxide. The transparent vapor deposition polyester film whose transparent vapor deposition layer of Claim 4 is a layer which uses aluminum oxide and silicon oxide.