JP2006241349A - Polyester film for molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester film for molding that is excellent in moldability at a low temperature under a low pressure, solvent resistance and heat resistance, hardly forms a deposit under a high temperature environment during processing and molding and after molding of the film, hardly suffers from deterioration in transparency, and has a light environmental load. <P>SOLUTION: The polyester film for molding is composed of a biaxially oriented polyester film constituted of a copolyester, has a stress at 100% elongation of 10-1,000 MPa at 25°C and 1-100 MPa at 100°C in each of the longitudinal direction and the width direction of the film, a storage viscoelastic modulus (E') of 10-1,000 MPa at 100°C and 5-40 MPa at 180°C in each of the longitudinal direction and the width direction of the film, and a heat distortion rate (in the longitudinal direction of the film) under a weak tension of -3 to +3% at 175°C, and gives an increase in haze of at most 0.3% after a heat treatment at 170°C for 10 min. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention has excellent moldability, particularly moldability under low temperature and low pressure, excellent solvent resistance and heat resistance, and is suitable as a member for home appliances, automobile nameplates or building materials, which have low environmental impact. The present invention relates to a molding polyester film that can be used.

  Conventionally, as a sheet | seat for shaping | molding, a polyvinyl chloride film is typical and has been preferably used at points, such as workability. On the other hand, the film has problems such as generation of toxic gas when the film burns due to a fire or the like, bleed-out of a plasticizer, and a new material with a small environmental load has been demanded due to recent environmental resistance needs. ing.

In order to satisfy the above requirements, unstretched sheets made of polyester, polycarbonate and acrylic resin have been used in a wide range of fields as non-chlorine materials. In particular, unstretched sheets made of a polyester resin are attracting attention because they have good mechanical properties and transparency, and are excellent in economic efficiency. For example, an unstretched polyester-based sheet comprising substantially non-crystalline polyester-based resin in which about 30 mol% of ethylene glycol component in polyethylene terephthalate is substituted with 1,4-cyclohexanedimethanol is disclosed ( For example, see Patent Documents 1 to 5).
Japanese Patent Laid-Open No. 9-156267 JP 2001-71669 A JP 2001-80251 A JP 2001-129951 A JP 2002-249652 A

  The above-mentioned unstretched polyester sheet satisfies market demands regarding moldability and laminate suitability, but because it is an unstretched sheet, it does not have sufficient heat resistance and solvent resistance and satisfies high market demands. It has not yet reached.

As a method for solving the above problems, a method using a biaxially stretched polyethylene terephthalate film is disclosed (for example, see Patent Documents 6 to 9).
JP-A-9-187903 JP-A-10-296937 Japanese Patent Laid-Open No. 11-10816 JP-A-11-268215

  However, although the heat resistance and solvent resistance are improved, the above method has insufficient moldability and does not satisfy the market demand in terms of the balance of overall quality.

As a method for solving the above-described problem, a method for specifying a stress at 100% elongation of a film is disclosed (for example, see Patent Document 10).
JP 2001-347565 A

  Although this method has improved moldability as compared with the above-described method, it does not reach a level that can sufficiently meet the high demands of the market regarding moldability. In particular, there remains a problem in moldability that can be adapted to lowering the molding temperature and the finished quality of the obtained molded product.

The inventors of the present invention have studied the solution of the above-mentioned problems, and have already developed a method for improving the above-mentioned problems by specifying a 100% elongation stress of the film using a copolymer polyester resin having the specified composition as a raw material. (For example, refer to Patent Documents 11 and 12).
Japanese Patent Application No. 2002-233694 Japanese Patent Application No. 2003-309894

  By these methods, in the mold molding method with high molding pressure at the time of molding, the moldability that can meet the market demand and can be adapted to the lowering of molding temperature and the finished product finished quality should be greatly improved. Can do. However, in the case of a molding method having a low molding pressure at the time of molding, such as a compressed air molding method or a vacuum molding method, which has become increasingly demanding in the market, it is desired to further improve the finish of the molded product.

  In addition, precipitates resulting from the cyclic trimer are generated due to heat during processing such as printing or vapor deposition on the film surface, and the quality of the printing surface or vapor deposition surface may be lowered. Further, when the film is molded, the mold is contaminated, the frequency of cleaning is increased, and the productivity is lowered. In addition, after molding the film, there is a problem that the transparency is lowered when the film is used at a high temperature. As described above, there is a strong demand from the market not only for moldability but also for improving precipitates and transparency deterioration due to heat not only in film processing and molding, but also in a high-temperature environment after molding.

  The object of the present invention is to solve the above-mentioned problems in the prior art, and is excellent in moldability, particularly moldability under low temperature and low pressure, solvent resistance and heat resistance, and film processing and molding The object is to provide a polyester film for molding that has a small amount of precipitates, a small decrease in transparency, and a small environmental load in a high-temperature environment after molding.

The polyester film for molding of the present invention capable of solving the above-mentioned problems has the following configuration.
That is, the first invention of the present invention is a molding polyester film made of a biaxially oriented polyester film, the film comprising a copolymer polyester as a constituent component,
(1) 100% elongation stress in the longitudinal direction and width direction of the film is 10 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C.,
(2) The storage viscoelastic modulus (E ′) in the longitudinal direction and the width direction of the film is 10 to 1000 MPa at 100 ° C. and 5 to 40 MPa at 180 ° C.,
(3) The thermal deformation rate in the longitudinal direction of the film (initial load 49 mN) is −3% to + 3% at 175 ° C.,
(4) A molding polyester film characterized in that an increase in haze after heat-treating the film at 170 ° C. for 10 minutes is 0.3% or less.

  A second invention is characterized in that the copolymer polyester comprises an aromatic dicarboxylic acid component and a glycol component containing ethylene glycol and a branched aliphatic glycol and / or alicyclic glycol as constituent components. It is a polyester film for a shaping | molding as described in 1 invention.

  According to a third invention, the polyester constituting the biaxially oriented polyester film further includes a 1,3-propanediol unit or a 1,4-butanediol unit as a glycol component. This is a polyester film for molding.

  4th invention is a polyester film for shaping | molding in any one of 1st-3rd invention characterized by the surface orientation degree of the said polyester film for shaping | molding being 0.095 or less.

  5th invention is the polyester film for shaping | molding, The heat shrink rate in 150 degreeC of the longitudinal direction and the horizontal direction of a film is 6.0% or less, The invention in any one of 1-4 characterized by the above-mentioned The polyester film for molding described in 1.

  A sixth aspect of the present invention is the molding polyester film according to any one of the first to fifth aspects, wherein the molding polyester film has a melting point of 200 to 45 ° C.

  In a seventh invention, the molding polyester film has a ratio (H / d) of haze H (%) to film thickness d (μm) of less than 0.010. The polyester film for molding according to any one of the inventions.

  An eighth invention is a molding polyester film obtained by using the molding polyester film as a base film and laminating a surface layer having a thickness of 0.01 to 5 μm on the base film, wherein the base film is It is a polyester film for molding according to any one of the first to seventh inventions, characterized in that it contains substantially no particles and contains particles only in the surface layer.

  A ninth invention is the molding polyester film according to the eighth invention, wherein the surface layer is mainly composed of an adhesion modifying resin and particles.

  The molding polyester film of the present invention is excellent in moldability at the time of heat molding, particularly at low temperature and low pressure, so it can be applied to a wide range of molding methods and used as a molded product in a room temperature atmosphere. On the other hand, it is excellent in elasticity and shape stability (heat shrinkage characteristics, thickness unevenness), in addition, it is excellent in solvent resistance and heat resistance, and also has a small environmental load. In addition, since the molding polyester film of the present invention has few cyclic trimers deposited on the film surface in a high temperature environment, when the film is heated, the transparency is lowered and the cyclic trimer is transferred to the film surface. Is suppressed. Therefore, there are few occurrences of precipitates when processing such as printing or vapor deposition on the film, less contamination of the mold at the time of molding processing, and further, high transparency can be maintained even when used at high temperature. Have Therefore, there is an advantage that it can be suitably used as a member for home appliances, automobile nameplates or building materials.

The polyester film for molding in the present invention has a 100% elongation stress (F100 ₂₅ ) at 25 ° C. in the longitudinal and width directions of the film of 10 to 1000 MPa, and 100 ° C. in the longitudinal and width directions of the film. It is important that the stress at 100% elongation (F100 ₁₀₀ ) is _{1 to 100} MPa. If F100 ₂₅ or F100 ₁₀₀ exceeds the upper limit of the above range, the moldability deteriorates, which is not preferable. On the other hand, if it is less than the lower limit of the above range, the elasticity and shape stability when using a molded product are lowered, which is not preferable.

F100 ₂₅ in the longitudinal direction and the width direction of the film is preferably 10 to 500 MPa, more preferably 10 to 200 MPa, and particularly preferably 10 to 150 MPa.

The upper limit of F100 ₁₀₀ in the longitudinal direction and the width direction of the film is preferably 90 MPa, more preferably 80 MPa, and particularly preferably 70 MPa from the viewpoint of moldability. On the other hand, the lower limit of F100 ₁₀₀ is preferably 2 MPa, more preferably 3 MPa, and particularly preferably 5 MPa from the viewpoint of elasticity and shape stability when using a molded product.

  In the polyester film for molding in the present invention, it is important that the storage viscoelastic modulus (E ′) in the longitudinal direction and the width direction of the film is 10 to 1000 MPa at 100 ° C. and 5 to 40 MPa at 180 ° C. is there. By controlling the storage viscoelasticity (E ′) within the above range, the moldability, particularly the moldability at a low temperature and low pressure can be secured, and the compressed air molding method and the vacuum molding that can only be applied to unstretched sheets. Even a molding method with a low molding pressure of 10 atm or less, such as a method, can provide a molded product with good finish and a molded product with good dimensional stability.

  The storage viscoelastic modulus (E ′) at 100 ° C. and 180 ° C. is a parameter that affects the moldability under low temperature and low pressure, dimensional stability, and the like. In particular, the present inventor shows that the storage viscoelasticity (E ′) at 100 ° C. is related to moldability under low temperature and low pressure, and the storage viscoelasticity (E ′) at 180 ° C. is related to dimensional stability. Have newly found out. The reason why the storage viscoelastic modulus (E ′) at the specific temperature is an important index for developing the film characteristics is not clear, but the copolymer component contained in the polyester constituting the film It is presumed that the molecular structure of

  The storage viscoelastic modulus (E ′) in the longitudinal direction and the width direction of the film is preferably 20 to 900 MPa, more preferably 30 to 800 MPa, and particularly preferably 40 to 700 MPa in both directions of the film at 100 ° C. The storage viscoelastic modulus (E ′) at 180 ° C. is preferably 7 to 38 MPa, more preferably 9 to 35 MPa, and particularly preferably 10 to 30 MPa.

  Further, it is important that the polyester film for molding in the present invention has a thermal deformation rate (initial load 49 mN) in the longitudinal direction of the film of −3% to + 3% at 175 ° C. The thermal deformation rate (initial load 49 mN) in the longitudinal direction of the film is preferably −3% to + 3% at 180 ° C., and particularly preferably −3% to + 3% at 185 ° C.

  Here, the thermal deformation rate of the film is measured using a thermomechanical analyzer (TMA) under conditions of an initial load of 49 mN and a heating rate of 5 ° C./min, and the dimensional change of the film accompanying the temperature change is measured. The thermal deformation rate at 175 ° C. is obtained. By controlling the thermal deformation rate (initial load 49 mN) in the longitudinal direction of the film within the above range, the solvent resistance of the molded product can be improved. Furthermore, a molded product with good finish can be obtained even by a method of molding at a low pressure of 10 atm or less, such as a compressed air molding method or a vacuum molding method. In the case of an unstretched sheet obtained from polyester, polycarbonate, or acrylic resin, the thermal deformation rate in the longitudinal direction of the film at 175 ° C. is outside the scope of the present invention.

  The reason why the seemingly unrelated characteristics of the thermal deformation rate and the solvent resistance under the micro tension (initial load 49 mN) of the film are correlated is not clear. However, as the above-mentioned reason, since the molding polyester film of the present invention is biaxially oriented, it is presumed that the solvent resistance and heat distortion resistance could be improved by the expression of molecular orientation by stretching.

  (1) Stress at 100% elongation in the longitudinal direction and width direction of the film, (2) Storage viscoelastic modulus (E ′) in the longitudinal direction and width direction of the film, (3) Under micro tension in the longitudinal direction of the film It is important that the thermal deformation ratio in the above satisfies the above range at the same time. When the film satisfies these characteristics at the same time, the molding polyester film of the present invention having the effect of satisfying the above various market requirements can be obtained.

  The molding polyester film of the present invention is a biaxially stretched polyester film containing a copolyester as a constituent component, and its structure, melting point, molecular weight, composition, etc. are not limited as long as the above properties are satisfied. Preferred embodiments of the molding polyester film of the present invention are described below.

  The polyester film for molding of the present invention is a biaxially oriented polyester comprising a copolymer polyester composed of an aromatic dicarboxylic acid component and ethylene glycol and a glycol component containing a branched aliphatic glycol and / or an alicyclic glycol. It is preferable to use it for a part or all of the raw material of the film.

  In the copolymerized polyester, the aromatic dicarboxylic acid component is mainly composed of terephthalic acid, naphthalene dicarboxylic acid, or an ester-forming derivative thereof. The amount of the terephthalic acid and / or naphthalene dicarboxylic acid component is 70 mol% with respect to the total dicarboxylic acid component. Above, preferably 85 mol% or more, particularly preferably 95 mol% or more, particularly preferably 100 mol%.

  Examples of the branched aliphatic glycol include neopentyl glycol, 1,2-propanediol, and 1,2-butanediol. Examples of the alicyclic glycol include 1,4-cyclohexanedimethanol and tricyclodecane dimethylol.

  Among these, neopentyl glycol and 1,4-cyclohexanedimethanol are particularly preferable. Furthermore, in the present invention, it is a more preferable embodiment that 1,3-propanediol or 1,4-butanediol is used as a copolymerization component in addition to the glycol component. Use of these glycols as a copolymerization component is suitable for imparting the above-mentioned properties, and is also excellent in transparency and heat resistance, and from the viewpoint of improving the adhesion with the adhesion modified layer. Is also preferable.

Furthermore, you may use together the following dicarboxylic acid component and / or glycol component as a copolymerization component in the said copolyester as needed, if necessary.
Other dicarboxylic acid components that can be used in combination with terephthalic acid or its ester-forming derivatives include (1) isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl 4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid Aromatic dicarboxylic acids such as diphenylsulfone dicarboxylic acid, 5-sodium sulfoisophthalic acid, phthalic acid or ester-forming derivatives thereof, (2) oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, Aliphatic dicarboxylic acids such as fumaric acid and glutaric acid or their ester-forming derivatives, (3) Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid or their ester-forming derivatives, (4) p-oxybenzoic acid, oxy Oxycarboxylic acids such as caproic acid or their esters Forming derivatives, and the like.

  On the other hand, other glycol components that can be used in combination with ethylene glycol and branched aliphatic glycol and / or alicyclic glycol include aliphatic glycols such as pentanediol and hexanediol, bisphenol A, bisphenol S, and the like. Aromatic glycols and their ethylene oxide adducts, diethylene glycol, triethylene glycol, dimer diol and the like can be mentioned.

  Furthermore, a polyfunctional compound such as trimellitic acid, trimesic acid, and trimethylolpropane can be further copolymerized with the copolymerized polyester as necessary.

  Examples of the catalyst used for producing the copolymer polyester include alkaline earth metal compounds, manganese compounds, cobalt compounds, aluminum compounds, antimony compounds, titanium compounds, titanium / silicon composite oxides, and germanium compounds. . Of these, titanium compounds, antimony compounds, germanium compounds, and aluminum compounds are preferred from the viewpoint of catalytic activity.

  When producing the copolymer polyester, it is preferable to add a phosphorus compound as a heat stabilizer. As said phosphorus compound, phosphoric acid, phosphorous acid, etc. are preferable, for example.

  The copolyester preferably has an intrinsic viscosity of 0.50 dl / g or more, more preferably 0.55 dl / g or more, and particularly preferably from the viewpoint of moldability, adhesion, and film formation stability. 60 dl / g or more. If the intrinsic viscosity is less than 0.50 dl / g, the moldability tends to decrease. In addition, when a filter for removing foreign substances is provided in the melt line, the upper limit of the intrinsic viscosity is preferably 1.0 dl / g from the viewpoint of ejection stability during extrusion of the molten resin.

  In the molding polyester film of the present invention, the copolymer polyester may be used as a film raw material as it is, or a copolymer polyester having a large amount of copolymer components is blended with a homopolyester (for example, polyethylene terephthalate) to obtain a copolymer component amount. May be adjusted.

  In particular, by forming a film using the latter blending method, transparency and a high melting point (heat resistance) can be achieved while maintaining the same flexibility as when only the copolyester is used. In addition, when only a high melting point homopolyester (for example, polyethylene terephthalate) is used, it is possible to realize a melting point (heat resistance) having no flexibility and practical problem while maintaining high transparency.

  Further, blending at least one or more of the copolymer polyester and a homopolyester other than polyethylene terephthalate (for example, polytetramethylene terephthalate or polybutylene terephthalate) and using it as a raw material for the molding polyester film of the present invention, It is further preferable from the viewpoint of moldability.

  The melting point of the polyester film is preferably 200 to 245 ° C. from the viewpoint of heat resistance and moldability. By controlling the type and composition of the polymer to be used and the film forming conditions within the range of the melting point, a balance between moldability and finish can be achieved, and a high-quality molded product can be produced economically. Here, the melting point is an endothermic peak temperature at the time of melting, which is detected at the time of primary temperature rise in so-called differential scanning calorimetry (DSC). The melting point was determined by measuring with a differential scanning calorimeter (DuPont, V4.OB2000 type) at a heating rate of 20 ° C./min. The lower limit of the melting point is more preferably 210 ° C, particularly preferably 230 ° C. If the melting point is less than 200 ° C, the heat resistance tends to deteriorate. Therefore, it may become a problem when exposed to high temperature during molding or use of a molded product.

  The upper limit of the melting point is preferably high from the viewpoint of heat resistance. However, when the polyethylene terephthalate unit is a main component, a film having a melting point exceeding 245 ° C tends to deteriorate moldability. In addition, transparency tends to deteriorate. Furthermore, in order to obtain high moldability and transparency, it is preferable to control the upper limit of the melting point to 240 ° C.

  Moreover, in order to improve handling properties, such as the slipperiness and winding property of a film, it is preferable to form an unevenness | corrugation on the film surface. As a method for forming irregularities on the film surface, a method of incorporating particles in the film is generally used.

  Examples of the particles include internal particles having an average particle size of 0.01 to 10 μm, external particles such as inorganic particles and / or organic particles. When particles having an average particle diameter exceeding 10 μm are used, defects in the film are liable to occur, and the design and transparency tend to deteriorate. On the other hand, in the case of particles having an average particle diameter of less than 0.01 μm, handling properties such as film slipperiness and winding property tend to be lowered. The lower limit of the average particle diameter of the particles is more preferably 0.10 μm, particularly preferably 0.50 μm, from the viewpoint of handling properties such as slipping property and winding property. On the other hand, the average particle diameter of the particles is more preferably 5 μm, particularly preferably 2 μm, from the viewpoint of transparency and reduction of film defects due to coarse protrusions.

  The average particle size of the particles is taken by taking a plurality of photographs of at least 200 particles by electron microscopy, tracing the outline of the particles on an OHP film, and converting the trace image to an equivalent circle diameter with an image analyzer. To calculate.

  Examples of the external particles include wet and dry silica, colloidal silica, aluminum silicate, titanium oxide, calcium carbonate, calcium phosphate, barium sulfate, alumina, mica, kaolin, clay, hydroxyapatite and the like, and styrene, silicone, acrylic Organic particles or the like containing acids as constituent components can be used. Among these, inorganic particles such as dry, wet and dry colloidal silica and alumina, and organic particles containing styrene, silicone, acrylic acid, methacrylic acid, polyester, divinylbenzene and the like as constituent components are preferably used. Two or more of these internal particles, inorganic particles and / or organic particles may be used in combination as long as the characteristics defined in the present invention are not impaired.

  Furthermore, the content of the particles in the film is preferably in the range of 0.001 to 10% by mass. When the amount is less than 0.001% by mass, the handling property is likely to be deteriorated, for example, the slipperiness of the film is deteriorated or winding becomes difficult. On the other hand, if it exceeds 10% by mass, it tends to cause formation of coarse protrusions, deterioration of film forming property and transparency.

Moreover, since the particle | grains contained in a film generally differ in refractive index from polyester, it becomes a factor which reduces the transparency of a film.
In many cases, the molded product is printed on the surface of the film before the film is molded in order to improve the design. Since such a printing layer is often applied to the back side of a molding film, it is desired that the transparency of the film is high from the viewpoint of printing clarity.

  Therefore, in order to obtain a high degree of transparency while maintaining the handleability of the film, the particles are not substantially contained in the base film of the main layer, and the particles are only in the surface layer having a thickness of 0.01 to 5 μm. It is effective to use a laminated film having a laminated structure containing.

  For example, in the case of inorganic particles, when the inorganic element is quantified by fluorescent X-ray analysis, 50 ppm or less, preferably 10 ppm or less, most preferably It means the content that is below the detection limit. This is because contaminants derived from foreign substances may be mixed without positively adding particles to the base film.

  The thin surface layer can be formed by a coating method or a coextrusion method. Especially, in the case of the coating method, since the adhesiveness with a printing layer can also be improved by using the composition which consists of adhesiveness modification resin containing particle | grains as an application layer, it is a preferable method. As said adhesive property modification resin, resin which consists of at least 1 sort (s) chosen from polyester, a polyurethane, an acrylic polymer, and / or those copolymers is preferable.

  Furthermore, in order to further improve the adhesion between the polyester film of the main layer and the adhesion modified layer, the surface of the polyester film of the main layer may be surface-treated in advance, and the adhesion modified layer may be provided on this surface-treated surface. Good. Examples of the surface treatment method include: (1) a method using irradiation with active energy rays such as corona discharge treatment, plasma discharge treatment, ultraviolet (UV) irradiation treatment, radiation (EB) irradiation treatment, (2) flame treatment, (3 ) Vapor deposit methods such as PVD and CVD.

  By setting it as such a laminated structure, ratio (H / d) of haze H (%) with respect to the thickness d (micrometer) of a film can be made into less than 0.010, maintaining the handling property of a film.

  In particular, when the molding polyester film is used for applications requiring transparency, the ratio (H / d) of haze H (%) to film thickness d (μm) is less than 0.010. Is preferable from the viewpoint of transparency and print sharpness. The H / d is more preferably more than 0 and less than 0.010, particularly preferably more than 0 and 0.009 or less. In the present invention, the numerical value of H / d is described in the third decimal place, but it is not rounded off after the fourth decimal place. For example, even 0.0099 is set to 0.009.

  The lower limit of H / d is preferably closer to zero from the viewpoint of transparency and print sharpness. However, if the essential minimum unevenness is not formed on the film surface, the handling properties such as the slipping property and the winding property deteriorate, and the film surface may be damaged or the productivity may deteriorate. Therefore, the lower limit value of H / d is preferably 0.001, and particularly preferably 0.005. In the case of a translucent nameplate using a backlight, a higher degree of transparency is required. Therefore, the H / d is preferably closer to zero.

  As the particles to be contained in the surface layer, the same particles as those described above can be used. Among the particles, silica particles, glass fillers, and silica-alumina composite oxide particles are particularly suitable from the viewpoint of transparency because the refractive index is relatively close to that of polyester.

  Moreover, when the surface layer contains particles having an average particle diameter of more than 10 μm, the frequency with which coarse protrusions are formed on the film surface increases, and the design property tends to deteriorate. On the other hand, in the case of particles having an average particle diameter of less than 0.01 μm, handling properties such as film slipperiness and winding property tend to be lowered. The preferable range of the average particle diameter of the particles is the same as that when the particles are contained in the base film of the main layer.

  Furthermore, the particle content in the surface layer is preferably in the range of 0.01 to 25% by mass. When the content is less than 0.01% by mass, handling properties are likely to deteriorate, for example, the slipperiness of the film is deteriorated or winding becomes difficult. On the other hand, when it exceeds 25 mass%, transparency and applicability tend to deteriorate.

  In order to impart other functions, the polyester film of the present invention can be made into a laminated structure by a known method using different types of polyester. The form of the laminated film is not particularly limited. For example, A / B two-type two-layer structure, B / A / B two-type three-layer structure, C / A / B three-type three-layer structure, etc. Laminated form is mentioned

  It is important that the molding polyester film of the present invention is a biaxially stretched film. In the present invention, due to molecular orientation by biaxial stretching, the thermal deformation rate of the film under micro tension (initial load 49 mN) can be controlled within the range of the present invention, which is a disadvantage of the unstretched sheet. Solvent resistance and dimensional stability are improved. That is, it is one of the features of the present invention that the solvent resistance and heat resistance, which are defects of the unstretched sheet, are improved while maintaining the good formability of the unstretched sheet.

  The method for producing the biaxially oriented polyester film is not particularly limited. For example, after drying the polyester resin as necessary, the polyester resin is supplied to a known melt extruder, extruded from a slit-shaped die into a sheet, and electrostatically applied. The method of sticking to a casting drum by this method, cooling and solidifying to obtain an unstretched sheet, and then biaxially stretching the unstretched sheet is exemplified.

  As the biaxial stretching method, a method is employed in which an unstretched sheet is stretched and heat-treated in the longitudinal direction (MD) and width direction (TD) of the film to obtain a biaxially stretched film having a desired in-plane orientation degree. . Among these methods, in terms of film quality, the MD / TD method in which the film is stretched in the longitudinal direction and then stretched in the width direction, or the TD / MD method in which the film is stretched in the width direction and then stretched in the longitudinal direction. An axial stretching method and a simultaneous biaxial stretching method in which the longitudinal direction and the width direction are stretched almost simultaneously are desirable. In the case of the simultaneous biaxial stretching method, a tenter driven by a linear motor may be used. Furthermore, if necessary, a multistage stretching method in which stretching in the same direction is performed in multiple stages may be used.

  The film stretching ratio when biaxially stretching is preferably 1.6 to 4.2 times in the longitudinal direction and the width direction, particularly preferably 1.7 to 4.0 times. In this case, the stretching ratio in the longitudinal direction and the width direction may be either larger or the same ratio. More preferably, the stretching ratio in the longitudinal direction is 2.8 to 4.0 times, and the stretching ratio in the width direction is 3.0 to 4.5 times.

  The stretching conditions for producing the molding polyester film of the present invention are not particularly limited. However, in order to satisfy the characteristics defined in the present invention, it is preferable to select, for example, the following conditions.

  In the longitudinal stretching, it is more preferable that the stretching temperature is 50 to 110 ° C. and the stretching ratio is 1.6 to 4.0 times so that the subsequent lateral stretching can be performed smoothly.

  Usually, when stretching the polyethylene terephthalate, if the stretching temperature is lower than the appropriate conditions, the yield stress increases rapidly at the beginning of the lateral stretching, and therefore stretching cannot be performed. Moreover, even if it can be stretched, it is not preferable because the thickness and the stretch ratio are likely to be non-uniform.

  In addition, when the stretching temperature is higher than appropriate conditions, the initial stress is low, but the stress does not increase even when the stretch ratio is high. Therefore, the film has a small stress at 100% elongation at 25 ° C. Therefore, by taking the optimum stretching temperature, a highly oriented film can be obtained while ensuring stretchability.

  However, when the copolymerized polyester contains 1 to 40 mol% of a copolymer component, the stretching stress rapidly decreases as the stretching temperature is increased so as to eliminate the yield stress. In particular, since the stress does not increase even in the latter half of the stretching, the orientation does not increase and the stress at 100% elongation at 25 ° C. decreases.

  Such a phenomenon is likely to occur when the thickness of the film is 60 to 500 μm, and is particularly noticeable in a film having a thickness of 100 to 300 μm. Therefore, in the case of a film using the copolymerized polyester of the present invention, the stretching temperature in the transverse direction is preferably set as follows.

First, the preheating temperature is preferably 50 ° C to 150 ° C. Next, in the first half of the transverse stretching, the stretching temperature is preferably −20 ° C. to + 25 ° C., particularly preferably −15 ° C. to + 25 ° C. with respect to the preheating temperature. In the second half of the transverse stretching, the stretching temperature is preferably 0 ° C. to −40 ° C., particularly preferably −10 ° C. to −40 ° C. with respect to the stretching temperature of the first half. By adopting such conditions, the first half of the transverse stretching is easy to stretch because the yield stress is small, and the second half is easily oriented. In addition, it is preferable that the draw ratio of a horizontal direction shall be 2.5 to 5.0 times. As a result, it is possible to obtain a film that satisfies F100 ₂₅ and F100 ₁₀₀ defined in the present invention.

  Furthermore, the film is heat-treated after biaxial stretching, and this heat treatment can be performed by a conventionally known method such as in an oven or on a heated roll. Further, the heat treatment temperature and the heat treatment time can be arbitrarily set according to the required level of heat shrinkage. The heat treatment temperature is preferably in the range of 120 to 245 ° C, particularly preferably 150 to 240 ° C. The heat treatment time is preferably 1 to 60 seconds. In addition, you may perform this heat processing, relaxing a film to the longitudinal direction and / or the width direction. In the present invention, the heat treatment temperature has a suitable range depending on the composition of the film raw material used, even within the range of the heat treatment temperature, so that the degree of plane orientation of the film is 0.095 or less. It is important to set The reason will be described in detail later.

  In order to reduce the thermal shrinkage rate at 150 ° C. in the longitudinal and lateral directions of the film, it is preferable to increase the heat treatment temperature, lengthen the heat treatment time, and perform relaxation treatment. Specifically, in order to set the heat shrinkage rate at 150 ° C. in the longitudinal direction and the width direction of the film to 6.0% or less, the heat treatment temperature is 200 to 220 ° C. and the relaxation rate is 1 to 8%. However, it is preferable to carry out. Furthermore, re-stretching may be performed once or more in each direction, and then heat treatment may be performed.

  In order to reduce the heat shrinkage rate at 150 ° C. in the longitudinal direction and the transverse direction of the film, it is difficult to lengthen the production line and lengthen the heat treatment time due to equipment limitations. Further, when the film feeding speed is slowed, productivity is lowered. Thus, it is important that the temperature of the section is as low as about 100 ° C. until the stretching section. On the other hand, in heat setting, it is important to quickly raise the temperature to about 200 ° C. Therefore, it is recommended as a preferred embodiment that a far infrared heater is installed in the heat treatment zone to reinforce the heating as a measure for solving the problem.

  Furthermore, there is a method in which a heat insulating section of 1 m or more is provided between the extending section and the heat fixing section to increase the heating efficiency after the heat insulating section. Specifically, the heating efficiency can be increased by strengthening the partition for each section to reduce the leakage of heat flow. Moreover, you may use the method which adjusts the pressure in oven and suppresses the leakage of a heat flow, ensuring air volume by adjusting the balance and strength of an air volume. For heating that is insufficient with hot air heating, a method of adding an infrared heater to the strong heating section is also suitable. In addition, the heating amount is increased by increasing the length of the heat fixing section and the number of sections. Such a method is also effective.

  The polyester film for molding of the present invention has a storage viscoelastic modulus (E ′) in the longitudinal and width directions of the film of 10 to 1000 MPa at 100 ° C. and 5 to 40 MPa at 180 ° C. In order to achieve such storage viscoelastic modulus (E ′), when the biaxially stretched film containing the above-described copolymer polyester as a constituent component is produced, the degree of plane orientation of the film is controlled within a specific range. It is also important. That is, it is preferable to lower the plane orientation degree of the film to 0.095 or less, and particularly preferably 0.001 to 0.090. Thus, the storage elastic modulus (E ') of the said film can be made small by making plane orientation degree low.

  However, the storage viscoelastic modulus (E ′) of the film at 180 ° C. becomes too small simply by reducing the plane orientation of the film. When a copolymerized polyester having a branched aliphatic glycol and / or alicyclic glycol as a copolymerization component, which is a preferred embodiment of the present invention, is used as a film raw material, molecules at a high temperature due to the bulk of the molecular structure of the glycols. Motility can be suppressed. Furthermore, the storage viscoelastic modulus (E ′) of the film at 180 ° C. can be controlled within the above range by synergistic means by lowering the degree of plane orientation of the film using specific stretching conditions. In addition, the combined effect of the 1,3-propanediol residue and 1,4-butanediol residue exemplified as a preferred embodiment is that the introduction of the component results in the formation of microcrystals in the copolymerized polyester molecule, resulting in the 180 ° C. This is presumably because the effect of suppressing the storage viscoelastic modulus (E ′) of the resin from becoming too small was exhibited.

  As described above, it is one of the preferred embodiments that the plane orientation degree of the biaxially oriented polyester film is set to a low level, but the means for imparting the characteristics is not limited and is arbitrary. In general, as means for lowering the degree of plane orientation, a method of lowering the draw ratio and a method of raising the heat setting temperature are known, but the former method is not preferred because the thickness unevenness of the film deteriorates. Therefore, the latter method is preferable. In the latter case, the above problem occurs, but it can be avoided by the method exemplified as a preferred embodiment.

  In the present invention, it is important to use a copolyester as the biaxially oriented polyester film. Since the copolymer polyester has a lower melting point than the homopolyester, when the heat setting temperature is increased, the film is easily fused to a clip that holds the film in the transverse stretching step. Therefore, it is important that the vicinity of the clip is sufficiently cooled when the clip releases the film at the tenter outlet.

  In order to prevent fusion between the film and the clip, for example, (1) a method of providing a heat shielding wall in the clip portion so that the clip is difficult to be heated, (2) a method of adding a clip cooling mechanism to the tenter, (3) A method for sufficiently cooling the entire film by setting a long cooling section after heat setting in order to enhance the cooling capacity, and (4) increasing the length of the cooling section and the number of sections to increase the cooling efficiency. It is preferable to employ a method of increasing, (5) a method of enhancing the cooling of the clip by using a type in which the return portion of the clip travels outside the furnace, and the like.

In the molding polyester film of the present invention, the cyclic trimer on the film surface is preferably 0.2 mg / m ² or less, more preferably 0.18 mg / m ² or less, particularly preferably 0.16 mg / m ^2. m ² or less. When the cyclic trimer on the surface of the film exceeds 0.2 mg / m ² , adhesion inhibition and defects occur when a functional layer or a functional film having various functions is laminated on the film, which is not preferable.

In the molding polyester film of the present invention, the cyclic trimer on the film surface when the polyester film is heated at 170 ° C. for 10 minutes is preferably 0.9 mg / m ² or less, more preferably 0.6 mg. / M ² or less, particularly preferably 0.3 mg / m ² .

  In the molding polyester film of the present invention, it is important that the increase in the haze of the film when heated at 170 ° C. for 10 minutes is 0.30% or less, preferably 0.25% or less. Preferably it is 0.20% or less. In addition, even if it heat-processes to a film, it is most preferable that the quantity and haze of the cyclic | annular trimer on the film surface do not change. However, in order to make the change in the characteristics zero, an extremely high level of technology is required, but from a practical point of view, if it can be managed within the above range, it can be used without any problem.

  When the increase in film haze when heated at 170 ° C. for 10 minutes exceeds 0.30%, when processing with heat such as printing or vapor deposition is performed, when molding at high temperature or under reduced pressure, When used in the above, the transfer of the cyclic trimer to the film surface is increased, and a decrease in transparency and a decrease in quality due to precipitates are observed.

  In order to increase the haze of the film when heated at 170 ° C. for 10 minutes to 0.30% or less, it is preferable to manage the cyclic trimer content in the polyester resin used as the film raw material to 5000 ppm or less, More preferably, it is controlled to 4500 ppm or less, particularly preferably 4000 ppm or less.

  The means for reducing the content of the cyclic trimer in the polyester resin is not limited, and examples thereof include a method of solid-phase polymerization of a polyester chip having an intrinsic viscosity of 0.40 to 0.60 dl / g. Moreover, the method of heat-processing the polyester resin of predetermined intrinsic viscosity on the conditions which an intrinsic viscosity does not change substantially in inert gas atmosphere or pressure reduction is also illustrated. Further, a method of extracting with a solvent that dissolves the cyclic trimer may be used.

  Moreover, in the melt extrusion process at the time of film manufacture, it is important to suppress the reproduction | regeneration of the cyclic trimer in the polyester resin of a molten state. In order to suppress the regeneration of the cyclic trimer in the molten polyester resin as much as possible, it is important to reduce the amount of the active polymerization catalyst remaining in the polyester resin as much as possible. As a typical means for reducing the amount of such an active polymerization catalyst, the following method may be mentioned.

  One means is a method of inactivating the polymerization catalyst by bringing the polyester used as a film raw material into contact with water.

  Examples of the method for deactivating the polycondensation catalyst in the polyester used as the film raw material include a water treatment method in which the polyester chip is contact-treated with water, water vapor or water vapor-containing gas after melt polycondensation or after solid phase polymerization.

  Examples of the water treatment method include a method of immersing in water and a method of applying water on the chip with a shower. The treatment time when performing the water treatment is preferably 5 minutes to 2 days, more preferably 10 minutes to 1 day, and particularly preferably 30 minutes to 10 hours. Moreover, the temperature of water is preferably 20 to 180 ° C, more preferably 40 to 150 ° C, and particularly preferably 50 to 120 ° C.

  Although the method of performing water treatment industrially is illustrated below, it is not limited to this. The treatment method may be either a continuous method or a batch method, but the continuous method is preferred for industrial use.

  A silo-type treatment tank is used when water-treating polyester chips in a batch system. In other words, the polyester chip is received in a silo in a batch system to perform water treatment. In the case where the polyester chips are water-treated in a continuous manner, the polyester chips can be continuously or intermittently received in the tower-type treatment tank from the upper part and water-treated.

  Further, when the polyester chip and water vapor or water vapor-containing gas are contacted, the water vapor or water vapor containing gas or water vapor containing air at a temperature of 50 to 150 ° C., preferably 50 to 110 ° C., is preferably granular polyethylene. A method in which granular polyethylene terephthalate and water vapor are brought into contact with each other by supplying or presenting water in an amount of 0.5 g or more as water vapor per 1 kg of terephthalate is preferable.

  The contact between the polyester chip and water vapor is usually performed for 10 minutes to 2 days, preferably 20 minutes to 10 hours.

  Below, although the method of industrially performing contact processing with granular polyethylene terephthalate, water vapor, or water vapor containing gas is illustrated, it is not limited to this. The processing method may be either a continuous method or a batch method.

  When a polyester chip is contact-treated with water vapor in a batch system, a silo type processing apparatus can be used. That is, a polyester chip is received in a silo, and contact processing is performed by supplying water vapor or water vapor-containing gas in a batch manner.

  When the polyester chips are continuously contacted with water vapor, it is possible to continuously receive granular polyethylene terephthalate from the upper part in a tower-type processing device and continuously supply water vapor in parallel flow or countercurrent to contact with water vapor. .

  In the case of treatment with water or steam, the granular polyethylene terephthalate is drained with a draining device such as a vibrating screen or a Simon Carter as necessary, and transferred to the next drying step by a conveyor.

  The polyester chip that has been contact-treated with water or water vapor can be dried by a commonly used polyester drying process. As a continuous drying method, a hopper-type ventilation dryer in which polyester chips are supplied from the upper part and a drying gas is supplied from the lower part is suitable. Moreover, as a method of drying by a batch method, a dryer that dries while aeration gas is passed under atmospheric pressure is preferable.

  As the dry gas, atmospheric air may be used, but dry nitrogen and dehumidified air are preferable from the viewpoint of preventing molecular weight reduction due to hydrolysis or thermal oxidative decomposition of polyester.

  As another means other than water treatment, a polyester resin used as a film raw material (hereinafter referred to as polyester resin (1)), mainly composed of an aromatic dicarboxylic acid and an ethylene glycol component, and a phosphorus compound as a phosphorus element is 100. A method of mixing and extruding a polycondensation catalyst depleted polyester resin (hereinafter referred to as polyester resin (2)) containing ˜5000 ppm is mentioned.

  Mixing of the polyester resin (1) and the polyester resin (2) may be performed before melt extrusion at the time of film production, or may be performed using a mixed polyester resin obtained by mixing both polyester resins and performing melt extrusion in advance. May be.

  Examples of the phosphorus compound contained in the polyester resin (2) include phosphoric acid compounds, phosphonic acid compounds, phosphinic acid compounds, phosphorous acid compounds, phosphonous acid compounds, and phosphinic acid compounds. .

  Examples of the phosphoric acid compound include phosphoric acid, dimethyl phosphate, diethyl phosphate, dipropyl phosphate, dibutyl phosphate, diamyl phosphate, dihexyl phosphate, trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, triamyl phosphate, triamyl phosphate Examples include hexyl phosphate and esters of phosphoric acid and alkylene glycol.

  Examples of phosphonic acid compounds include methylphosphonic acid, methylphosphonic acid dimethyl, methylphosphonic acid diphenyl, phenylphosphonic acid, phenylphosphonic acid dimethyl, phenylphosphonic acid diphenyl, benzylphosphonic acid dimethyl, benzylphosphonic acid diethyl, triethylphosphonoacetate, tributyl. Examples thereof include phosphonoacetate, tri (hydroxyethyl) phosphonoacetate, tri (hydroxypropyl) phosphonoacetate, and tri (hydroxybutyl) phosphonoacetate.

  Examples of the phosphinic acid compound include diphenylphosphinic acid, methyl diphenylphosphinate, phenyl diphenylphosphinate, phenylphosphinic acid, methyl phenylphosphinate, phenylphenylphosphinate, 2-carboxyethyl-methylphosphinic acid, 2-carboxyethyl. -Ethylphosphinic acid, 2-carboxyethyl-propylphosphinic acid, 2-carboxyethyl-phenylphosphinic acid, 2-carboxyethyl-m-toluylphosphinic acid, 2-carboxyethyl-p-toluylphosphinic acid, 2-carboxyethyl- Xylylphosphinic acid, 2-carboxyethyl-benzylphosphinic acid, 2-carboxyethyl-m-ethylbenzylphosphinic acid, 2-carboxymethyl-methylphosphinic acid, 2-carbo Cymethyl-ethylphosphinic acid, 2-carboxyethyl-propylphosphinic acid, 2-carboxymethyl-phenylphosphinic acid, 2-carboxymethyl-m-toluylphosphinic acid, 2-carboxymethyl-p-toluylphosphinic acid, 2-carboxymethyl -Xylylphosphinic acid, 2-carboxymethyl-benzylphosphinic acid, 2-carboxymethyl-m-ethylbenzylphosphinic acid, and cyclic anhydrides thereof, or methyl ester, ethyl ester, propyl ester, butyl ester, Examples thereof include ethylene glycol ester, propion glycol ester, and ester with butanediol.

  Phosphorous acid compounds include, for example, phosphorous acid and dimethyl phosphite, diethyl phosphite, dipropyl phosphite, dibutyl phosphite, diamyl phosphite, dihexyl phosphite, trimethyl phosphite, triethyl phosphite, triphenyl Phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tetrakis (2,4-di-tert-butylphenyl) 4,4'-biphenylene diphosphite, phosphorous acid and alkylene glycol Examples include esters.

  Examples of the phosphonous acid compound include methylphosphonous acid, dimethyl methylphosphonite, diphenyl methylphosphonous acid, phenylphosphonous acid, dimethyl phenylphosphonous acid, and diphenyl phenylphosphonous acid.

  The phosphorous compound may be the same or different from that used for the polyester resin (1), but phosphoric acid or its derivative is preferably used.

  The polyester resin (2) is a thermoplastic polyester mainly obtained from an aromatic dicarboxylic acid component and a glycol component, and is preferably a polyester containing aromatic dicarboxylic acid units of 70 mol% or more of the acid component. More preferably, it is a polyester containing 85 mol% or more of an aromatic dicarboxylic acid unit, and particularly preferably a polyester containing 95 mol% or more of an aromatic dicarboxylic acid unit of an acid component, Copolymerized or blended.

  Examples of the aromatic dicarboxylic acid component constituting the polyester resin (2) include aromatic dicarboxylic acids such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl 4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid, and the like. Examples thereof include functional derivatives thereof.

  Examples of the glycol component constituting the polyester resin (2) include aliphatic glycols such as ethylene glycol, 1,3-trimethylene glycol, and tetramethylene glycol, and alicyclic glycols such as cyclohexanedimethanol. .

  The polyester resin (2) is preferably a polyester whose main structural unit is composed of ethylene terephthalate, more preferably 70 mol% or more of ethylene terephthalate units, and isophthalic acid, neopentyl glycol, 1, It is a copolyester containing 4-cyclohexanedimethanol and the like, and particularly preferably a polyester containing 90 mol% or more of ethylene terephthalate units.

  When the polyester resin (2) is a copolymer, at least one of a dicarboxylic acid component or a glycol component is used in combination with at least one of the dicarboxylic acid component and the glycol component when the raw material is charged. Hereinafter, a copolymer polyester in which a copolymer component is introduced into the main chain of ethylene terephthalate in polyethylene terephthalate starting from terephthalic acid and ethylene glycol will be described as a representative example of the polyester resin (2).

  When dicarboxylic acid is used as a copolymerization component, isophthalic acid, diphenyl 4,4'-dicarboxylic acid, diphenoxyethane dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl ketone are used as the dicarboxylic acid. Aromatic dicarboxylic acids such as dicarboxylic acids and functional derivatives thereof, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, fats such as adipic acid, sebacic acid, succinic acid, glutaric acid and dimer acid Aromatic dicarboxylic acids and functional derivatives thereof, alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, and cyclohexanedicarboxylic acid, and functional derivatives thereof can be used.

  When glycol is used as a copolymerization component, diethylene glycol, 1,3-trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, 2-ethyl-2- Aliphatic glycols such as butyl-1,3-propanediol, neopentyl glycol, dimer glycol, 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol 2,5-norbornane dimethylol and other alicyclic glycols, xylylene glycol, 4,4'-dihydroxybiphenyl, 2,2-bis (4'-β-hydroxyethoxyphenyl) propane, bis It is possible to use aromatic glycols such as 4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfonic acid, alkylene oxide adducts of bisphenol A, polyalkylene glycols such as polyethylene glycol, polybutylene glycol, and the like. it can.

  Furthermore, when using a polyfunctional compound as another copolymerization component, trimellitic acid, pyromellitic acid, or the like can be used as the acid component, and glycerin or pentaerythritol can be used as the glycol component. However, the blending amount of these polyfunctional compounds must be such that the polyester is substantially linear. Monofunctional compounds such as benzoic acid and naphthoic acid may be copolymerized.

  The polyester resin (2) is a method of copolymerizing by adding the phosphorus compound at the time of polycondensation, or kneading at least one selected from a general-purpose polyester resin and the phosphorus compound with an extruder, for example, a twin screw extruder. However, it is not limited to these.

  In the case of the method of copolymerization by adding the above phosphorus compound at the time of polycondensation of the polyester resin (2), for example, a polyester obtained by adding a phosphorus compound at the time of polycondensation of terephthalic acid and ethylene glycol for copolymerization is a representative example. The production method will be described below.

  In any method employed for the polycondensation of an esterification reaction product or a transesterification product of terephthalic acid or an ester-forming derivative thereof (for example, dimethyl terephthalate) with ethylene glycol into a polyester. Can be synthesized. The phosphorus compound is added during the production of the polyester, and the addition time can be added at any stage from the initial stage of the esterification process to the late stage of the initial condensation. It is preferable to add it after the completion of the conversion step and later in the initial condensation. In the case of the transesterification method, it can be added before the transesterification reaction, during the transesterification reaction, or at any stage from the end of the transesterification reaction to the late stage of the initial condensation.

For example, in the case of the direct esterification method, the following production conditions are preferable.
The esterification reaction is carried out at 230 to 250 ° C. under normal pressure to increased pressure for 0.5 to 5 hours so that the esterification reaction rate is at least 95%, preferably 98% or more. Next, the first stage polycondensation is carried out at 240 to 255 ° C., preferably 240 to 250 ° C., more preferably 240 to 248 ° C., and 300 to 0.1 Torr for 0.5 to 2 hours. Further, the polycondensation is carried out at 250 to 290 ° C., preferably 250 to 280 ° C., more preferably 250 to 275 ° C., and 10 to 0.1 Torr, preferably 5 to 0.1 Torr to the desired degree of polymerization. The phosphorus compound is added at any stage from the end of esterification to the end of the first stage polycondensation. It is also important to carry out the first stage polycondensation reaction at 250 ° C. or lower.

  Examples of the starting material terephthalic acid or ethylene glycol include virgin terephthalic acid derived from para-xylene or ethylene glycol derived from ethylene, as well as methanol decomposition and ethylene glycol decomposition from used PET bottles. A recovered raw material such as terephthalic acid, bishydroxyethyl terephthalate or ethylene glycol recovered by the chemical recycling method can also be used as at least a part of the starting raw material. Needless to say, the quality of the recovered raw material must be refined to a purity and quality suitable for the intended use.

  Examples of the polycondensation catalyst used in the production of the polyester resin (2) include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, indium, thallium, germanium, tin, lead, bismuth, and scandium. , Yttrium, Niobium, Zirconium, Hafnium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Ruthenium, Rhodium, Palladium, Tellurium, Tantalum, Tungsten, Gallium, Aluminum, Antimony, Germanium, Titanium, Silicon, Silver One or more metal compounds selected from the group consisting of, etc. are used, and in particular, antimony compounds, germanium compounds, and tungsten compounds are most suitable because the catalytic action is not easily deactivated by the phosphorus compounds. That. In addition, you may use the same thing as the polycondensation catalyst used when manufacturing the said polyester resin (1).

  Specific examples of the antimony compound include antimony trioxide, antimony acetate, antimony tartrate, antimony tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, and triphenylantimony.

  Specific examples of the germanium compound include amorphous germanium dioxide, crystalline germanium dioxide, germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, germanium phosphite. And the like.

  Tungsten compounds include compounds such as tungstic acid, lithium tungstate, potassium tungstate, sodium tungstate, calcium tungstate, barium tungstate, cobalt tungstate, copper tungstate, manganese tungstate, tungsten ethoxide, ammonium tungstate, etc. Is mentioned.

Further, in the production of the polyester resin (2), a basic nitrogen compound can be used in order to suppress the production of diethylene glycol. As the basic nitrogen compound, any of aliphatic, alicyclic, aromatic and heterocyclic nitrogen compounds may be used.
Examples include triethylamine, tributylamine, dimethylaniline, dimethylaniline, pyridine, quinoline, dimethylbenzylamine, piperidine, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, triethylbenzylammonium hydroxide, imidazole, and imidazoline. These compounds may be used in free form or as a salt of lower fatty acid or TPA.

  The addition of these basic nitrogen compounds to the reaction system can be appropriately selected at any stage until the initial polycondensation reaction is completed, and may be used alone or in combination of two or more. Also good. The blending amount of these basic nitrogen compounds is preferably 0.01 to 1 mol%, more preferably 0.05 to 0.7 mol%, particularly preferably 0.1 to 0. 5 mol%.

  Further, when the production of the polyester resin (2) is performed by a method of blending a phosphorus compound with a general-purpose polyester resin, a method of melt-kneading the dried polyester resin and the phosphorus compound with a twin screw extruder into a chip, A method in which the polyester resin granules are immersed in an aqueous solution of a phosphorus compound or an organic solvent, or a method in which these solutions are attached to the surface is suitable.

  The intrinsic viscosity of the polyester resin (2) is preferably 0.45 to 1.00 dl / g, more preferably 0.48 to 0.90 dl / g, and particularly preferably 0.50 to 0.85 dl. / G, most preferably 0.55 to 0.80 dl / g. The polyester resin (2) having an intrinsic viscosity of 0.60 dl / g or more is preferably produced by a method in which a polymer obtained by melt polycondensation is polymerized in a solid state.

  When the intrinsic viscosity is less than 0.45 dl / g, there are problems such that breakage frequently occurs during film production, transparency of the obtained film is lowered, and mechanical strength is lowered. In addition, in order to produce a polyester resin having an intrinsic viscosity exceeding 1.00 dl / g, the polycondensation time is very long, resulting in an increase in cost. When a film is produced by kneading 2) with another polyester resin, the kneading is incomplete and it becomes difficult to obtain a film of uniform quality.

  In addition, the polyester resin (2) has a known ultraviolet absorber, antioxidant, oxygen scavenger, externally added particles, and internal components during the polymerization reaction to such an extent that the physical properties such as polymer color and hydrolyzability are not impaired. It is also possible to use various additives such as internally precipitated particles, release agents, nucleating agents, stabilizers, antistatic agents, bluing agents, dyes, pigments, and the like.

  The polyester resin (1) and the polyester resin (2) may have the same or different polyester skeleton.

  Furthermore, the activity of the polycondensation catalyst of the polyester resin (1) may be deactivated by directly mixing the phosphorus compound with the polyester resin (1). When using the deactivation method of the catalytic activity of the polyester with the phosphorus compound, the phosphorus compound may be mixed with the polyester resin (1) before the melt extrusion step during film production, or the polyester resin (1) in advance. A polyester resin obtained by mixing and phosphorus extrusion with a phosphorus compound may be used as a film raw material. That is, you may implement by any method of the method of mixing a phosphorus compound with a polyester resin (1), melt-extruding, or the method of adding a phosphorus compound to a molten polyester resin (1). Moreover, you may use together the method of mixing said polyester resin (1) and polyester resin (2), and the method of mixing a phosphorus compound directly to polyester resin (1).

In the method of deactivating the polycondensation catalyst by the phosphorus compound, for example, Al atoms and P atoms of a polyester film obtained by forming a film using a polyester obtained by an aluminum-based polycondensation catalyst system remain. The blending ratio of the polyester resin (1) to the polyester resin (2) and the phosphorus compound is adjusted so that the molar ratio (P / Al) and the residual amount of P atoms are the amounts represented by the following formulas (1) and (2). It is preferable to adjust.
2.5 ≦ P / Al (molar ratio) ≦ 20 (1)
20 ≦ P (ppm) ≦ 200 (2)
In both cases, if the amount is less than the lower limit, the deactivation effect of the polycondensation catalyst is insufficient, and the effect of suppressing the formation of the cyclic trimer in the molten state of the polyester resin in the film forming step is not preferable. On the other hand, if the upper limit value is exceeded, the deactivation effect of the polycondensation catalyst is saturated, and an undesired phenomenon such as a decrease in the intrinsic viscosity of the polyester resin is caused.

  In addition, the molding polyester film of the present invention may be used as a molded body in a place where sunlight is irradiated. When used in applications requiring such light resistance, the light transmittance at a wavelength of 350 nm of the molding polyester film is preferably controlled to 1% or less, more preferably 0.8% or less, and particularly preferably. 0.6% or less. By controlling the light transmittance at a wavelength of 350 nm to 1% or less, the light resistance of the printing layer is improved when printing is performed on the molding polyester film, particularly the film.

  The method of controlling the light transmittance at a wavelength of 350 nm to 1% or less is optional without limitation, but a method of blending an ultraviolet absorber in any of the constituent layers of the molding polyester film is recommended. The ultraviolet absorber used in the method may be appropriately selected without limitation as long as the above-described characteristics can be imparted. Either inorganic or organic may be used. Examples of organic ultraviolet absorbers include benzotoazole, benzophenone, cyclic imino ester, and combinations thereof. From the viewpoint of heat resistance, benzotoazole and cyclic imino ester are preferred. When two or more kinds of ultraviolet absorbers are used in combination, ultraviolet rays having different wavelengths can be absorbed simultaneously, so that the ultraviolet absorption effect can be further improved.

  Examples of the benzotriazole ultraviolet absorber include 2- [2′-hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl). ) Phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxypropyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyhexyl) phenyl ] -2H-benzotriazole, 2- [2'-hydroxy-3'-tert-butyl-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-tert -Butyl-3 '-(methacryloyloxyethyl) phenyl] -2 -Benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-chloro-2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyethyl) phenyl] -5-methoxy-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5'-( Methacryloyloxyethyl) phenyl] -5-tert-butyl-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazole, and the like. However, it is not particularly limited to these.

  Examples of the cyclic imino ester ultraviolet absorber include 2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazin-4-one), 2-methyl-3,1-benzoxazine. -4-one, 2-butyl-3,1-benzoxazin-4-one, 2-phenyl-3,1-benzoxazin-4-one, 2- (1- or 2-naphthyl) -3,1- Benzoxazin-4-one, 2- (4-biphenyl) -3,1-benzoxazin-4-one, 2-p-nitrophenyl-3,1-benzoxazin-4-one, 2-m-nitrophenyl -3,1-benzoxazin-4-one, 2-p-benzoylphenyl-3,1-benzoxazin-4-one, 2-p-methoxyphenyl-3,1-benzoxazin-4-one, 2- o-methoxy Enyl-3,1-benzoxazin-4-one, 2-cyclohexyl-3,1-benzoxazin-4-one, 2-p- (or m-) phthalimidophenyl-3,1-benzoxazin-4-one 2,2 '-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one) 2,2'-bis (3,1-benzoxazin-4-one), 2, 2'-ethylenebis (3,1-benzoxazin-4-one), 2,2'-tetramethylenebis (3,1-benzoxazin-4-one), 2,2'-decamethylenebis (3 1-benzoxazin-4-one), 2,2′-p-phenylenebis (3,1-benzoxazin-4-one), 2,2′-m-phenylenebis (3,1-benzoxazine-4 -On), 2,2 '-(4,4 '-Diphenylene) bis (3,1-benzoxazin-4-one), 2,2'-(2,6- or 1,5-naphthalene) bis (3,1-benzoxazin-4-one), 2 , 2 '-(2-methyl-p-phenylene) bis (3,1-benzoxazin-4-one), 2,2'-(2-nitro-p-phenylene) bis (3,1-benzoxazine- 4-one), 2,2 '-(2-chloro-p-phenylene) bis (3,1-benzoxazin-4-one), 2,2'-(1,4-cyclohexylene) bis (3 1-benzoxazin-4-one) 1,3,5-tri (3,1-benzoxazin-4-on-2-yl) benzene, 1,3,5-tri (3,1-benzoxazine-4 -On-2-yl) naphthalene and 2,4,6-tri (3,1- Zooxazin-4-on-2-yl) naphthalene, 2,8-dimethyl-4H, 6H-benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,6 -Dione, 2,7-dimethyl-4H, 9H-benzo (1,2-d; 5,4-d ') bis- (1,3) -oxazine-4,9-dione, 2,8-diphenyl 4H , 8H-benzo (1,2-d; 5,4-d ′) bis- (1,3) -oxazine-4,6-dione, 2,7-diphenyl 4H, 9H-benzo (1,2-d 5,4-d ') bis- (1,3) -oxazine-4,6-dione, 6,6'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 6 , 6'-bis (2-ethyl-4H, 3,1-benzoxazin-4-one), 6,6'-bis (2-phenyl-4H) , 3,1-benzoxazin-4-one), 6,6′-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-methylenebis (2-phenyl-4H) , 3,1-benzoxazin-4-one), 6,6′-ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-ethylenebis (2-phenyl) -4H, 3,1-benzoxazin-4-one), 6,6'-butylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-butylenebis (2-phenyl) -4H, 3,1-benzoxazin-4-one), 6,6'-oxybis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-oxybis (2-phenyl) -4H, 3,1-benzoxa -4-one), 6,6′-sulfonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6′-sulfonylbis (2-phenyl-4H, 3,1) -Benzoxazin-4-one), 6,6'-carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-carbonylbis (2-phenyl-4H, 3 , 1-benzoxazin-4-one), 7,7′-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-methylenebis (2-phenyl-4H, 3 , 1-benzoxazin-4-one), 7,7′-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7′-ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 7 7'-oxybis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7'-sulfonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 7 , 7'-carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,7'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,7'-bis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,7'-methylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), And 6,7'-methylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one).

  When blending the above-mentioned organic ultraviolet absorber into a film, it is exposed to a high temperature in the extrusion process. Therefore, it is necessary to use an ultraviolet absorber having a decomposition start temperature of 290 ° C. or higher as a process contamination during film formation. It is preferable in order to reduce it. If an ultraviolet absorber having a decomposition start temperature of 290 ° C. or lower is used, the decomposed product of the ultraviolet absorber adheres to the roll group of the manufacturing apparatus during film formation, and may reattach to the film or be damaged. Since it becomes an optical fault, it is not preferable.

  Examples of inorganic ultraviolet absorbers include ultrafine particles of metal oxides such as cerium oxide, zinc oxide, and titanium oxide.

  As another method for reducing the light transmittance at a wavelength of 350 nm to 1% or less, a method of using a compound having an absorption in this wavelength region, such as naphthalenedicarboxylic acid, for example, as a copolymerization component of polyester. be able to.

  As described above, by using the molding polyester film of the present invention, it is difficult to mold with the conventional biaxially oriented polyester film, and the vacuum at a molding pressure of 10 atm or less is low. Also in molding methods such as molding and pressure molding, it is possible to obtain a molded product with good finish. In addition, these molding methods are advantageous in terms of economy in the production of molded products because the molding costs are low. Therefore, application to these molding methods can most effectively exert the effect of the molding polyester film of the present invention.

  On the other hand, although the mold and the molding apparatus are expensive and disadvantageous in terms of economy, mold molding is characterized in that a molded product having a more complicated shape than that of the molding method is molded with high accuracy. Therefore, when molding using the molding polyester film used in the present invention, molding is possible at a lower molding temperature compared to conventional biaxially oriented polyester film, and the finished quality of the molded product is improved. The remarkable effect that it is done is expressed.

  Furthermore, the molded product thus molded has excellent elasticity and shape stability (heat shrinkage characteristics, thickness unevenness) when used in a room temperature atmosphere, and also has excellent solvent resistance and heat resistance, as well as environmental impact. Therefore, it can be suitably used as a molding member for home appliance nameplates, automobile nameplates, dummy cans, building materials, decorative plates, decorative steel plates, transfer sheets and the like.

  The molding polyester film of the present invention is also suitable as a molding material material to be molded using a molding method such as press molding, laminate molding, in-mold molding, drawing molding, or bending molding, in addition to the above molding method. is there.

  Hereinafter, the present invention will be described in detail by way of examples. The film properties obtained in each example were measured and evaluated by the following methods.

(1) Intrinsic viscosity 0.1 g of a chip sample was precisely weighed, dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane = 60/40 (mass ratio), and measured at 30 ° C. using an Ostwald viscometer. In addition, the measurement was performed 3 times and the average value was calculated | required.

(2) Content of cyclic trimer in polyester resin 300 mg of a sample is dissolved in 3 ml of a hexafluoroisopropanol / chloroform mixed solution (volume ratio = 2/3), and further diluted with 30 ml of chloroform. To this is added 15 ml of methanol to precipitate the polymer, followed by filtration. The filtrate was evaporated to dryness, brought to a constant volume with 10 ml of dimethylformamide, and the cyclic trimer was quantified by high performance liquid chromatography.

(3) Film thickness Using a millitron, a total of 15 points were measured, 5 points per sheet, and the average value was determined.

(4) Haze Based on JIS-K7136, it measured using the haze meter (Nippon Denshoku Industries Co., Ltd. make, 300A). In addition, the measurement was performed twice and the average value was calculated | required.

(5) Increase in haze after heat-treating the film at 170 ° C. for 10 minutes (ΔH)
Under no load, the haze of the film before and after being heat-treated in a gear oven at 170 ° C. for 10 minutes was measured, and the difference between the haze after the heat treatment and the haze before the heat treatment was defined as ΔH. In addition, the measurement of haze was based on JIS-K7136, and was measured using the haze meter (Nippon Denshoku Industries Co., Ltd. make, 300A). In addition, the measurement was performed twice and the average value was calculated | required.

(6) Amount of cyclic trimer on the film surface An oligomer deposited on the surface is dissolved by bringing an A4 size film into contact with chloroform for 5 minutes. About the obtained chloroform solution, the cyclic trimer was quantified by the high performance liquid chromatography method. The amount of the cyclic trimer on the film surface (mg / m ² ) was determined by dividing the amount of the cyclic trimer by the surface area of the film.

(7) Stress at 100% elongation, elongation at break With respect to the longitudinal direction and the width direction of the biaxially stretched film, a sample was cut into a strip shape having a length of 180 mm and a width of 10 mm, respectively, with a single-blade razor. Next, the strip-shaped sample was pulled using a tensile tester (manufactured by Toyo Seiki Co., Ltd.), and the stress at 100% elongation (MPa) and elongation at break (%) in each direction were determined from the obtained load-strain curve. .

  The measurement was performed in an atmosphere of 25 ° C. under the conditions of an initial length of 40 mm, a distance between chucks of 100 mm, a crosshead speed of 100 mm / min, a recorder chart speed of 200 mm / min, and a load cell of 25 kgf. In addition, this measurement was performed 10 times and the average value was used.

  In addition, a tensile test was performed under the same conditions as described above even in an atmosphere at 100 ° C. At this time, the sample was held for 30 seconds in an atmosphere at 100 ° C. and then measured. In addition, the measurement was performed 10 times and the average value was used.

(8) Storage viscoelastic modulus (E ')
Storage at 100 ° C. and 180 ° C. in the longitudinal direction (MD) and width direction (TD) of the film using a dynamic viscoelasticity measuring apparatus (DVA 225, manufactured by IT Measurement Control Co., Ltd.) under the following conditions: The elastic modulus (E ′) was determined.
(A) Sample width: 5 mm
(B) Measurement temperature range: −50 to 250 ° C.
(C) Frequency: 10Hz
(D) Temperature rising rate: 5 ° C./min

(9) Degree of plane orientation (ΔP)
Using a sodium D line (wavelength 589 nm) as a light source and using an Abbe refractometer, the refractive index (Nz) in the longitudinal direction of the film, the refractive index (Ny) in the width direction, and the refractive index (Nz) in the thickness direction are measured. The degree of plane orientation (ΔP) was calculated from the equation.
ΔP = ((Nx + Ny) / 2) −Nz

(10) Thermal deformation rate of the film at 175 ° C. Using a thermomechanical analyzer (manufactured by Seiko Electronics Co., Ltd., TMA SS / 100), the dimensional change in the longitudinal direction of the film accompanying the temperature change is continuously performed under the following conditions. And the thermal deformation rate in the longitudinal direction of the film at 175 ° C. was determined.
(A) Sample width: 2 mm
(B) Measurement temperature range: 30 to 250 ° C.
(C) Initial load: 49 mN (5 gf)
(D) Temperature rising rate: 5 ° C./min

(11) Thermal contraction rate at 150 ° C. A strip-shaped sample having a length of 250 mm and a width of 20 mm is cut out in the longitudinal direction and the width direction of the film, respectively. Two marks are made at intervals of 200 mm in the length direction of each sample, and the distance A between the two marks is measured under a constant tension of 5 gf (tension in the length direction). Subsequently, one side of each strip-shaped sample is hung with a clip under no load on the basket, and placed in a gear oven under an atmosphere of 150 ° C., and time is taken. After 30 minutes, the basket is removed from the gear oven and left at room temperature for 30 minutes. Next, for each sample, under a constant tension of 5 gf (longitudinal tension), the interval B between the two marks is read with a gold finger in units of 0.25 mm. From the read intervals A and B, the thermal shrinkage rate at 150 ° C. of each sample is calculated by the following formula.
Thermal contraction rate (%) = ((A−B) / A) × 100

(12) Thickness unevenness A continuous tape-like sample having a length of 3 m in the transverse stretching direction and a length of 5 cm in the longitudinal stretching direction is wound up, and the thickness of the film is measured with a continuous film thickness measuring machine (manufactured by Anritsu Co., Ltd.). To record. From the chart, the maximum value (Tmax), the minimum value (Tmin), and the average value (Tav) of the thickness were obtained, and the thickness unevenness (%) was calculated by the following formula. In addition, the measurement was performed 3 times and the average value was calculated | required. Moreover, when the length of a horizontal extending direction is less than 3 m, it joins and performs. In addition, the measurement data in the connection part was deleted.
Unevenness of thickness (%) = ((Tmax−Tmin) / Tav) × 100

(13) Light transmittance at a wavelength of 350 nm Using a spectrophotometer (manufactured by Shimadzu Corporation, UV-1200), the light transmittance in the ultraviolet region of a wavelength of 350 nm was measured.

(14) Formability (a) Vacuum formability After 5 mm square printing is performed on the film, the film is heated with an infrared heater heated to 500 ° C for 10 to 15 seconds, and then at a mold temperature of 30 to 100 ° C. Vacuum forming was performed. In addition, the heating conditions selected the optimal conditions within the said range with respect to each film. The shape of the mold was a cup shape, the opening had a diameter of 50 mm, the bottom part had a diameter of 40 mm, the depth was 50 mm, and all corners were curved with a diameter of 0.5 mm. .

Five molded products that were vacuum-molded under the optimum conditions were evaluated for moldability and finish, and ranked according to the following criteria. In addition, (double-circle) and (circle) were set as the pass, and x was set as the disqualification.
A: (i) There is no tear in the molded product,
(Ii) The corner radius of curvature is 1 mm or less, and the printing deviation is 0.1 mm or less,
(Iii) Furthermore, there is no appearance defect corresponding to ×: (i) The molded product is not torn,
(Ii) The corner radius of curvature is more than 1 mm and not more than 1.5 mm, or printing deviation is 0.1
greater than 0.2 mm and less than 0.2 mm,
(Iii) Furthermore, there is no appearance defect corresponding to ×, and there is no problem in practical use. ×: The molded product is torn, or any of the following items (i) to (iv) is not torn. (I) A corner with a radius of curvature exceeding 1.5 mm (ii) A poor appearance with large wrinkles (iii) A film with whitened and reduced transparency (iv) No print misalignment . More than 2mm

(B) Compressive air moldability After 5 mm square printing is performed on the film, the film is heated for 10 to 15 seconds with an infrared heater heated to 500 ° C., and then subjected to 4 atm at a mold temperature of 30 to 100 ° C. Crushing was performed under pressure. In addition, the heating conditions selected the optimal conditions within the said range with respect to each film. The shape of the mold is a cup shape, the opening has a diameter of 60 mm, the bottom has a diameter of 55 mm, a depth of 50 mm, and all corners are curved with a diameter of 0.5 mm. .

The moldability and finish of five molded products that were pressure-molded under optimal conditions were evaluated and ranked according to the following criteria. In addition, (double-circle) and (circle) were set as the pass, and x was set as the disqualification.
A: (i) There is no tear in the molded product,
(Ii) The corner radius of curvature is 1 mm or less, and the printing deviation is 0.1 mm or less,
(Iii) Furthermore, there is no appearance defect corresponding to ×: (i) The molded product is not torn,
(Ii) The corner radius of curvature is more than 1 mm and not more than 1.5 mm, or printing deviation is 0.1
greater than 0.2 mm and less than 0.2 mm,
(Iii) Furthermore, there is no appearance defect corresponding to ×, and there is no problem in practical use. ×: The molded product is torn, or any of the following items (i) to (iv) is not torn. (I) A corner with a radius of curvature exceeding 1.5 mm (ii) A poor appearance with large wrinkles (iii) A film with whitened and reduced transparency (iv) No print misalignment . More than 2mm

(C) Mold formability After printing on the film, contact heating with a hot plate heated to 100 to 140 ° C for 4 seconds, followed by press molding at a mold temperature of 30 to 70 ° C and a holding time of 5 seconds. It was. In addition, the heating conditions selected the optimal conditions within the said range with respect to each film. The shape of the mold is a cup shape, the opening has a diameter of 50 mm, the bottom has a diameter of 40 mm, a depth of 30 mm, and all corners are curved with a diameter of 0.5 mm. .

The moldability and finish of the five molded products molded under optimal conditions were evaluated and ranked according to the following criteria. In addition, (double-circle) and (circle) were set as the pass, and x was set as the disqualification.
A: (i) There is no tear in the molded product,
(Ii) The corner radius of curvature is 1 mm or less, and the printing deviation is 0.1 mm or less,
(Iii) Furthermore, there is no appearance defect corresponding to ×: (i) The molded product is not torn,
(Ii) The corner radius of curvature is more than 1 mm and not more than 1.5 mm, or printing deviation is 0.1
greater than 0.2 mm and less than 0.2 mm,
(Iii) Furthermore, there is no appearance defect corresponding to ×, and there is no problem in practical use. ×: The molded product is torn, or any of the following items (i) to (iv) is not torn. (I) A corner with a radius of curvature exceeding 1.5 mm (ii) A poor appearance with large wrinkles (iii) A film with whitened and reduced transparency (iv) No print misalignment . More than 2mm

(15) Solvent resistance The sample was immersed in toluene adjusted to 25 ° C. for 30 minutes, and the appearance change before and after the immersion was determined according to the following criteria, and “◯” was accepted. The haze value was measured by the method described above.
○: Little change in appearance, change in haze value is less than 1% ×: Change in appearance is observed, or change in haze value is 1% or more

(16) Print quality The film before printing was heat-treated at 90 ° C. for 30 minutes, and then four-color screen printing was performed.
Furthermore, the film provided with the printing layer was dried at 80 ° C. for 30 minutes. Evaluation of printing quality was made by visually judging the printing appearance such as the following clear feeling, printing suitability, printing misalignment and the like through the film from the back side, not from the printing side. As the judgment criteria, “O” indicates that there is no problem from all viewpoints, and “X” indicates that there is a problem in at least one point.
a. Clear feeling: The printed pattern is blocked by the base film or coating layer.
It should look clear without any problems.
b. Printability: Color unevenness and missing due to poor transfer of printing ink
Do not follow c. Printing misalignment: The misalignment of printing cannot be determined visually.

(17) Light resistance In the dark box, the offset printed sample is placed at a position 3 cm directly below the fluorescent lamp (manufactured by Matsushita Electric Co., Ltd., U-type fluorescent lamp FUL9EX). placed. Next, light was continuously irradiated for 2000 hours, and the color difference (ΔE value) was measured according to JIS Z 8730 based on the color (a *, b *, L *) before and after the light irradiation on the printing surface side. . The smaller the color difference (ΔE value), the smaller the color change before and after the light irradiation, that is, the better the light resistance. The acceptable level of light resistance is 0.5 or less in color difference (ΔE value). The color difference (ΔE value) is calculated by the following formula.
ΔE = √ (Δa ² + Δb ² + ΔL ² )

Example 1
The following three types of polyester resins A1, B1, and B5 were prepared as film materials.
The first polyester resin (A1) has an intrinsic viscosity of 0 as an aromatic dicarboxylic acid component and a terephthalic acid unit of 100 mol%, a diol component of an ethylene glycol unit of 40 mol% and a neopentyl glycol unit of 60 mol%. .69 dl / g copolymerized polyester.
The second polyester resin (B1) is polyethylene terephthalate containing 0.04% by mass of amorphous silica having an intrinsic viscosity of 0.69 dl / g and an average particle diameter (SEM method) of 1.5 μm.

The above chip (A1) and chip (B1) were produced using an aluminum-based catalyst, and the polyester resin was dried at 160 ° C. under reduced pressure. Then, nitrogen gas containing 400 ppm of ethylene glycol was added to 1 kg of crude polyester. The reaction system was adjusted to a slight pressure of 1.2 kg / cm ² and heated at 215 ° C. for 20 hours to reduce the oligomer (low OLG). The intrinsic viscosity of the obtained polyester was almost the same as that before the treatment, and the content of the cyclic trimer was 3900 ppm.

  The third polyester resin (B5) is a catalyst-reused polyethylene terephthalate having an intrinsic viscosity of 0.61 dl / g and containing 2000 ppm of phosphorus compounds in terms of phosphorus atoms. In addition, catalyst deutilization polyester (B5) was obtained by the following method.

(Manufacture of polyester resin (B5) that lost catalyst)
A batch polymerization can is charged with high-purity terephthalic acid and twice its molar amount of ethylene glycol, 0.3 mol% of triethylamine is added to the acid component, and water is removed from the system at 245 ° C under a pressure of 0.25 MPa. The esterification reaction was carried out for 120 minutes while distilling off to obtain a mixture of bis (2-hydroxyethyl) terephthalate and oligomer (hereinafter referred to as BHET mixture) having an esterification rate of 95%. In this BHET mixture, a germanium dioxide / ethylene glycol slurry and an ester of ethylene glycol and phosphoric acid (mono-, di-, tri-, ester mixture) / ethylene glycol solution were used as polycondensation catalysts. It added so that it might be set to 50 ppm in terms of atoms and 2000 ppm in terms of P atoms, and polycondensation was carried out according to a conventional method to obtain a catalyst deutilizing polyester resin having an IV of 0.61 dl / g. The obtained polyester resin was dried at 160 ° C. under reduced pressure, and then nitrogen gas containing 400 ppm of ethylene glycol was circulated at 40 liters per kg of crude polyester at a rate of 1.2 kg / cm ² . The pressure was adjusted to a slight pressure, heat treatment was performed at 215 ° C. for 20 hours, and a low oligomer (low OLG) treatment was performed, and the cyclic trimer content was reduced to 3200 ppm.

  After drying the copolymer polyester (A1) chip, the particle-containing polyethylene terephthalate (B1) chip, and the catalyst depleted polyester resin (B5) chip containing 2000 ppm in terms of P atoms, A1 / B1 It mixed so that it might become mass ratio of / B5 = 25/70/5. Next, these chip mixtures were melt-extruded from the slit of the T die at 270 ° C. by an extruder and rapidly cooled and solidified on a chill roll having a surface temperature of 40 ° C. A stretched sheet was obtained.

  The obtained unstretched sheet was stretched 3.3 times at 90 ° C. in the longitudinal direction between the heating roll and the cooling roll. Next, the uniaxially stretched film was guided to a tenter, preheated at 120 ° C. for 10 seconds, and the first half of the transverse stretching was stretched 3.9 times at 110 ° C. and the latter half at 100 ° C. Further, a heat setting treatment was performed at 235 ° C. while performing a relaxation treatment of 7% in the transverse direction to obtain a biaxially stretched polyester film having a thickness of 100 μm.

  In the heat setting zone, an intermediate section of 2 m is provided between the stretching section, a far infrared heater is installed in the heating section of the heat setting zone, and the limit position where the shielding plate in each section does not contact the film Expanded and installed. Also in the cooling section after heating, section shielding is strengthened, an external return method is used as a clip return method, a clip cooling device is installed, and forced cooling is performed with cold air of 20 ° C., and the clip temperature at the tenter outlet is set to 40. Measures were taken to prevent clip fusion to below ℃.

Comparative Example 1
In Example 1, a biaxially stretched polyester film was obtained in the same manner as in Example 1 except that the heat setting temperature was changed to 205 ° C.

Comparative Example 2
In the production of the copolymerized polyester (A1) and the particle-containing PET (B1) of Example 1, the copolymerized polyester (A2) and the polyester (A2) were prepared in the same manner as in Example 1 except that the low oligomer (OLG) treatment was not performed. Particle-containing PET (B2) was obtained. In Example 1, in the same manner as in Example 1 except that the copolymer polyester (A2) chip and the particle-containing PET (B2) chip were mixed so that the mass ratio was A2 / B2 = 25/75. A biaxially stretched polyester film was obtained. The copolymerized polyester (A2) and particle-containing PET (B2) obtained in this comparative example contained 7000 ppm of a cyclic trimer.

Comparative Example 3
Characteristic evaluation of a commercially available unstretched sheet of A-PET (Toyobo Co., Ltd., PETMAX® A560GE0R, thickness: 200 μm) was performed.

Comparative Example 4
Characteristic evaluation of a commercially available unstretched polycarbonate sheet (manufactured by Teijin Chemicals Ltd., Panlite Sheet (R) PC2151, thickness: 200 μm) was performed.

Comparative Example 5
Characteristic evaluation of an unstretched acrylic sheet (manufactured by Mitsubishi Kasei Co., Ltd., Acryprene (R) HBS006, thickness: 125 μm) was performed.

Example 2
A copolymer polyester (A3) having an intrinsic viscosity of 0.77 dl / g, comprising 100 mol% of terephthalic acid units as aromatic dicarboxylic acid components, 70 mol% of ethylene glycol units and 30 mol% of neopentyl glycol units as diol components. ), A chip of polyethylene terephthalate (B3) containing 0.04% by mass of amorphous silica having an intrinsic viscosity of 0.63 dl / g and an average particle diameter (SEM method) of 1.5 μm, and an intrinsic viscosity Of polypropylene terephthalate (C) containing 0.04% by mass of amorphous silica having an average particle size (SEM method) of 1.5 μm and an average particle size (SEM method) of 0.75 dl / g. The copolymer PEs (A3), particle-containing PET (B3), and PTT (C) used were those subjected to a low oligomer (low OLG) treatment in the same manner as in Example 1. All the polyesters had a cyclic trimer content of 3900 ppm. A copolymer / PEs (A3) chip, a particle-containing PET (B3) chip, a PTT (C) chip, and a catalyst-defeated PEs resin (B5) chip are A3 / B3 / C / B5 = 50/5/40. It mixed so that it might become mass ratio of / 5. Next, these chip mixtures were melt-extruded from the slit of the T die at 270 ° C. by an extruder and rapidly cooled and solidified on a chill roll having a surface temperature of 40 ° C. A stretched sheet was obtained.

  The obtained unstretched sheet was stretched 3.5 times at 83 ° C. in the longitudinal direction between the heating roll and the cooling roll. Next, the uniaxially stretched film was guided to a tenter, preheated at 95 ° C. for 10 seconds, and the first half of the transverse stretching was stretched 3.9 times at 80 ° C. and the latter half at 75 ° C. Further, a heat setting treatment was performed at 200 ° C. while performing a relaxation treatment of 7% in the transverse direction to obtain a biaxially stretched polyester film having a thickness of 100 μm.

  In the heat setting zone, an intermediate section of 2 m is provided between the stretching section, a far infrared heater is installed in the heating section of the heat setting zone, and the limit position where the shielding plate in each section does not contact the film Expanded and installed. Also in the cooling section after heating, section shielding is strengthened, an external return method is used as a clip return method, a clip cooling device is installed, and forced cooling is performed with cold air of 20 ° C., and the clip temperature at the tenter outlet is set to 40. Measures were taken to prevent clip fusion to below ℃.

Example 3
As an aromatic dicarboxylic acid component, a terephthalic acid unit of 100 mol%, a diol component of an ethylene glycol unit of 70 mol% and a 1,4-cyclohexanedimethanol unit of 30 mol% as constituent components, an intrinsic viscosity of 0.71 dl / g. Polymerized polyester chip (A4), particle-containing polyethylene terephthalate chip (B1), and catalyst depleted polyester resin (B5) chip were mixed so that the mass ratio was A4 / B1 / B5 = 50/45/5. And dried. The copolymer polyester (A4) used was subjected to low oligomerization treatment in the same manner as in Example 1. The copolymerized polyester (A4) after the low oligomer (low OLG) treatment also had a cyclic trimer content of 3900 ppm. Next, these chip mixtures were melt-extruded from the slit of the T die at 270 ° C. by an extruder and rapidly cooled and solidified on a chill roll having a surface temperature of 40 ° C. A stretched sheet was obtained.

  The obtained unstretched sheet was stretched 3.5 times at 90 ° C. in the longitudinal direction between the heating roll and the cooling roll. Next, the uniaxially stretched film was guided to a tenter, preheated at 120 ° C. for 10 seconds, and the first half of the transverse stretching was stretched 3.9 times at 105 ° C. and the latter half at 100 ° C. Furthermore, a heat setting treatment was performed at 220 ° C. while performing a relaxation treatment of 7% in the transverse direction to obtain a biaxially stretched polyester film having a thickness of 100 μm.

  In the heat setting zone, an intermediate section of 2 m is provided between the stretching section, a far infrared heater is installed in the heating section of the heat setting zone, and the limit position where the shielding plate in each section does not contact the film Expanded and installed. Also in the cooling section after heating, section shielding is strengthened, an external return method is used as a clip return method, a clip cooling device is installed, and forced cooling is performed with cold air of 20 ° C., and the clip temperature at the tenter outlet is set to 40. Measures were taken to prevent clip fusion to below ℃.

Comparative Example 6
In Example 3, a biaxially stretched polyester film having a thickness of 100 μm was obtained in the same manner as in Example 3 except that the heat setting temperature was changed to 205 ° C.

Example 4
Copolyester (A1) having an intrinsic viscosity of 0.69 dl / g, comprising 100 mol% of terephthalic acid units as aromatic dicarboxylic acid components, 40 mol% of ethylene glycol units and 60 mol% of neopentyl glycol units as diol components. And a polybutylene terephthalate (D) chip containing 0.04% by mass of amorphous silica having an intrinsic viscosity of 0.69 dl / g and an average particle diameter (SEM method) of 1.5 μm were dried. . These polyester chips used were those subjected to low oligomer (low OLG) treatment in the same manner as in Example 1. Next, a chip of copolymerized PEs (A1), a chip of PBT (D), a benzotriazole-based ultraviolet absorber (E) (manufactured by Ciba Specialty Chemicals Co., Ltd., Tinuvin 326) was added to A1 / D / E = 25. It mixed so that it might become a mass ratio of 0 / 74.5 / 0.5. Next, these mixtures were melt-extruded from the slit of the T die at 265 ° C. by an extruder, rapidly cooled and solidified on a chill roll having a surface temperature of 20 ° C., and at the same time, the amorphous unstretched film was adhered to the chill roll using an electrostatic application method. A sheet was obtained.

  The obtained unstretched sheet was stretched 3.3 times at 80 ° C. in the longitudinal direction between the heating roll and the cooling roll. Next, the uniaxially stretched film was guided to a tenter, preheated at 95 ° C. for 10 seconds, and the first half of the transverse stretching was stretched 3.8 times at 85 ° C. and the latter half at 80 ° C. Further, a heat setting treatment was performed at 200 ° C. while performing a relaxation treatment of 7% in the transverse direction to obtain a biaxially stretched polyester film having a thickness of 100 μm.

  In the heat setting zone, an intermediate section of 2 m is provided between the stretching section, a far infrared heater is installed in the heating section of the heat setting zone, and the limit position where the shielding plate in each section does not contact the film Expanded and installed. Also in the cooling section after heating, section shielding is strengthened, an external return method is used as a clip return method, a clip cooling device is installed, and forced cooling is performed with cold air of 20 ° C., and the clip temperature at the tenter outlet is set to 40. Measures were taken to prevent clip fusion to below ℃.

Comparative Example 7
In Example 4, a biaxially stretched polyester film having a thickness of 100 μm was obtained in the same manner as in Example 4 except that the heat setting temperature was changed to 185 ° C.

Example 5
(Coating solution adjustment)
A water-soluble urethane resin (1st solid copolymer 3.15% by mass of copolymer polyester resin (Toyobo Co., Ltd., Vylonal MD-1250) and a terminal isocyanate group blocked with a hydrophilic group in a 40% by mass aqueous solution of isopropanol (first Elastolone H-3) manufactured by Kogyo Seiyaku Co., Ltd. is a silica having a solid content of 5.85% by mass and an average particle size of 1.0 μm of silica particles of 0.8% by mass and an average particle size of 0.05 μm based on the total resin. The coating solution was adjusted so that the particles contained 10% by mass with respect to the total resin. The obtained coating solution was adjusted to pH 6.5 using a 5% by mass aqueous sodium bicarbonate solution. Subsequently, it filtered with the bag type filter (Sumitomo 3M Co., Ltd. make, liquid filter bag), and stirred at 15 degreeC in the coating liquid circulation system stock tank for 2 hours.

(Manufacture of laminated film)
In Example 1, instead of the polyethylene terephthalate chip (B1), the polyethylene terephthalate chip (B4) having a cyclic trimer content of 3500 ppm and substantially no particles and an intrinsic viscosity of 0.69 dl / g ) Was used in the same manner as in Example 1 to obtain an amorphous unstretched sheet. The discharge amount of the molten resin was adjusted so that the final film thickness was 188 μm.

  The obtained unstretched sheet was stretched 3.3 times at 90 ° C. in the longitudinal direction between the heating roll and the cooling roll. Subsequently, the said coating liquid was apply | coated to the single side | surface of a uniaxially stretched film so that the thickness of the resin solid content before extending | stretching might be set to 0.9 micrometer by the reverse kiss coating method. The laminated film having the coating layer was guided to a tenter while being dried, preheated at 120 ° C. for 10 seconds, and the first half of transverse stretching was stretched 3.9 times at 110 ° C. and the latter half at 100 ° C. Furthermore, a heat setting treatment was performed at 235 ° C. while performing a relaxation treatment of 7% in the transverse direction to obtain a biaxially stretched polyester film having a thickness of 188 μm and having a coating layer on one side.

  In the heat setting zone, an intermediate section of 2 m is provided between the stretching section, a far infrared heater is installed in the heating section of the heat setting zone, and the limit position where the shielding plate in each section does not contact the film Expanded and installed. Also in the cooling section after heating, section shielding is strengthened, an external return method is used as a clip return method, a clip cooling device is installed, and forced cooling is performed with cold air of 20 ° C., and the clip temperature at the tenter outlet is set to 40. Measures were taken to prevent clip fusion to below ℃.

Comparative Example 8
Comparative Example 8 is an experiment in which Example 1 of Japanese Patent Laid-Open No. 2001-347565 was re-examined and compared with the prior art.
Wet dimethyl terephthalate and ethylene glycol, magnesium acetate (M) and antimony trioxide as catalyst, phosphoric acid (P) as additive, wet method silica with an average particle size (SEM method) of 1.5 μm (0.08% by mass) ) Was added, and polyethylene terephthalate was polymerized by a conventional method to obtain a polyethylene terephthalate (PET) chip (B6). The obtained PET chip (B6) had an intrinsic viscosity of 0.65 dl / g, a carboxyl end group concentration of 25 eq / ton, and an M / P molar ratio of 2.5.

  The PET chip (B6) was vacuum-dried at 180 ° C. for 4 hours, then supplied to a melt extruder, extruded into a sheet from a slit-shaped die, and adhered to a mirror surface cooling drum by electrostatic application (3.0 kV). An unstretched sheet was prepared by cooling and solidification. The unstretched sheet was first stretched 3.0 times in the longitudinal direction with a roll heated to a temperature of 105 ° C., further stretched 3.2 times in the width direction at a stretching temperature of 125 ° C., and then at 195 ° C. A biaxially stretched polyester film having a thickness of 100 μm and a degree of plane orientation of 0.138 was obtained by performing 6% relaxation in the direction and heat treatment for 6 seconds.

Comparative Example 9
The comparative example 9 is an experiment in which Example 2 of Japanese Patent Laid-Open No. Hei 2-204020 is re-examined and compared with the prior art.
A copolymer polyester (A5) comprising 94 mol% terephthalic acid and 6 mol% adipic acid units as the dicarboxylic acid component, and 70 mol% ethylene glycol units and 30 mol% 1,4-cyclohexanedimethanol units as the diol component; . After mixing polyethylene terephthalate (B7) containing 2000 ppm of kaolin of 1 μm at a mass ratio of A5 / B7 = 70/30, pre-crystallization and dry crystallization are performed, and extrusion is performed from an extruder having a T die at 285 ° C. It was rapidly cooled and solidified to obtain an amorphous sheet having an intrinsic viscosity of 0.70 dl / g.
The obtained sheet was stretched 3.3 times in the machine direction at 85 ° C., and then stretched 3.5 times in the transverse direction at 100 ° C. to relax 10% in the width direction and 0.5% in the machine direction. While relaxing, heat treatment was performed at 185 ° C. to obtain a biaxially oriented polyester film having an average thickness of 38 μm.

  Regarding Examples 1 to 5 and Comparative Examples 1 and 5 to 12, Table 1 shows the raw material composition and polymer properties of the polymers used, and Tables 2 to 5 show the production conditions and properties of the films. Table 6 shows the film characteristics of Comparative Examples 2 to 4.

  Regarding Examples 1 to 5 and Comparative Examples 1, 2, and 6 to 9, Table 1 shows the raw material composition and polymer characteristics of the polymers used, and Tables 2 to 5 show the production conditions and characteristics of the films. Table 6 shows the film characteristics of Comparative Examples 3 to 5.

  Even if the biaxially oriented polyester films obtained in Examples 1 to 5 were molded by a vacuum molding method or a pressure molding method having a low molding pressure at the time of molding, molded products having good finish were obtained. Moreover, the solvent resistance and dimensional stability of the obtained molded product were also good. Further, the amount of the cyclic trimer on the film surface was small, and the increase in the amount of the cyclic trimer on the film surface when heat-treated was small. Accordingly, there was little mold contamination during molding. Moreover, since the film obtained in Example 4 contained an ultraviolet absorber, the light transmittance in the ultraviolet region at a wavelength of 350 nm was 0.6%. Therefore, the color difference on the printed surface side before and after light irradiation for 2000 hours was 0.5 or less, and the light resistance was excellent. Moreover, since the film obtained in Example 5 was excellent in transparency compared with the film obtained in Example 1 which contains a silica particle in a base film, it was excellent in printing quality.

  On the other hand, the films obtained in Comparative Examples 1, 6, 7 and 8 were inferior in moldability by the vacuum forming method or the pressure forming method, and the finished quality of the molded product was not good. Furthermore, the film obtained by these comparative examples was inferior in the finish property by the metal mold method compared with the film obtained in Examples 1-4. Moreover, since the film obtained in Comparative Example 2 has a large amount of cyclic trimer on the film surface and a large increase in the amount of cyclic trimer on the film surface when heat-treated, the transparency of the film is increased by heating. Declined. There were also many mold stains. Moreover, although the unstretched sheet of Comparative Examples 3-5 and Comparative Example 9 had good moldability, they were inferior in solvent resistance and dimensional stability.

  The molding polyester film of the present invention is excellent in moldability at the time of heat molding, particularly moldability at a low temperature and low pressure, and therefore can be applied to a wide variety of molding methods. Furthermore, when used as a molded product in a room temperature atmosphere, there are advantages that it is excellent in elasticity and shape stability (heat shrinkage characteristics, thickness unevenness), excellent in solvent resistance and heat resistance, and has a small environmental load. In addition, since the content of the cyclic trimer is small, there are advantages such as the occurrence of defects due to the cyclic trimer, mold contamination during molding, and a decrease in transparency. Furthermore, by providing a printability improving layer on the film, various printing decoration methods such as letterpress printing, intaglio printing, planographic printing, screen printing, offset printing, gravure printing, inkjet printing, flexographic printing, and textile printing, transfer, Three-dimensional processing is performed by applying designs such as printing layers, design layers, etc. by decorative methods such as painting, painting, vapor deposition, sputtering, CVD, and lamination, and then molding by various molding methods such as die molding, pressure molding, and vacuum molding. It is suitable for decoration methods and has excellent in-mold moldability and emboss moldability. Therefore, it is suitable as a member for nameplates or building materials of home appliances and automobiles, and contributes greatly to the industry.

Claims (9)

It is a polyester film for molding made of a biaxially oriented polyester film, and the film has a copolymer polyester as a constituent component,
(1) 100% elongation stress in the longitudinal direction and width direction of the film is 10 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C.,
(2) The storage viscoelastic modulus (E ′) in the longitudinal direction and the width direction of the film is 10 to 1000 MPa at 100 ° C. and 5 to 40 MPa at 180 ° C.,
(3) The thermal deformation rate under micro tension in the longitudinal direction of the film is −3% to + 3% at 175 ° C.
(4) A polyester film for molding, wherein the increase in haze after heat-treating the film at 170 ° C. for 10 minutes is 0.3% or less.   2. The molding polyester according to claim 1, wherein the copolymerized polyester includes an aromatic dicarboxylic acid component, a glycol component containing ethylene glycol, and a branched aliphatic glycol and / or an alicyclic glycol. Polyester film.   3. The polyester film for molding according to claim 2, wherein the polyester constituting the biaxially oriented polyester film further contains a 1,3-propanediol unit or a 1,4-butanediol unit as a glycol component.   The polyester film for molding according to any one of claims 1 to 3, wherein the molding polyester film has a plane orientation degree of 0.095 or less.   The polyester film for molding according to any one of claims 1 to 4, wherein the film shrinkage rate at 150 ° C in the longitudinal direction and the transverse direction of the film is 6.0% or less. .   The molding polyester film according to any one of claims 1 to 5, wherein the molding polyester film has a melting point of 200 to 45 ° C.   7. The molding polyester film according to claim 1, wherein the ratio (H / d) of haze H (%) to film thickness d (μm) is less than 0.010. 8. Polyester film for molding.   A molding polyester film comprising the molding polyester film as a base film, and a surface layer having a thickness of 0.01 to 5 μm laminated on the base film, wherein the base film substantially contains particles. The molding polyester film according to claim 1, wherein the particles are contained only in the surface layer.   9. The polyester film for molding according to claim 8, wherein the surface layer is mainly composed of an adhesion modifying resin and particles.