WO2002006372A1 - Easily formable polyester film - Google Patents

Abstract

A polyester film characterized in that it comprises as a component a polyester (A) obtained from monomers including at least two glycol ingredients selected among ethylene glycol, butanediol, and propanediol, and that the polyester (A), in temperature-rising DSC, gives a crystal fusion temperature curve having substantially one peak and has a fusion peak temperature of 230°C or higher and the polyester (A) satisfies the following relationship (1). The film is suitable for use in producing formed, processed, or printed products or as a material film therefor. M / P ≤ 1 (1) [In the relationship, M represents the concentration (mmol%) of a catalytic metal element remaining in the polyester (A) and P represents the amount (mmol%) of phosphorus remaining in the polyester (A).]

Description

 Description Easy-forming polyester film Technical field

 TECHNICAL FIELD The present invention relates to a polyester film for molding, and can be used for various industrial materials, packaging materials, building materials, and the like. More specifically, the present invention relates to a polyester film for molding suitable for surface coating of metal, wood, paper, resin, and the like, laminating, molding and embossing of containers such as cups and packs. Also, the present invention relates to an unstretched or biaxially stretched polyester film for molding, which is suitable as a process film such as a transfer printing support film used for in-mold transfer molding or the like which is printed simultaneously with molding in injection molding or the like.

Background art

 Conventionally, polyvinyl chloride film has been used as a typical decorative sheet used for covering the surface of metal, wood, paper, resin, and the like in terms of processability. However, since polyvinyl chloride contains a halogen element in the constituents of the polymer, it generates toxic components such as dioxin when incinerated or burns due to a fire, etc., and bleeds out the plasticizer. Because of these problems, there has been a growing demand for reducing environmental impact in recent years, and new materials have been required.

 Furniture, building materials, electrical appliances, automotive interior goods, containers and other plastic products and decorative sheets used to cover metal surfaces, and transfer printing films or transfer printing that apply patterns to the surface when molding. The support film used is formed into more complex three-dimensional shapes, folded after lamination, embossing, and deep drawing, due to the diversification of product life, handling, and design needs. There is a need for something that can withstand this.

On the other hand, Japanese Patent Laid-Open Publication No. Hei 3-667628 proposes a biaxially stretched polyester film for molding having improved workability at 150 ° C. In addition, it is not satisfactory in terms of A polyester film copolymerized with a long-chain aliphatic dicarboxylic acid and a polyester film copolymerized with an alicyclic glycol, which are described in Japanese Patent Application Publication No. Although it has good heat resistance and solvent resistance, it was not satisfactory in terms of thermal whitening during the molding process and solvent whitening during printing. In addition, amorphous polyethylene terephthalate film called A-PET film has high stress during molding and processing, and when molded at high temperature to further reduce stress, wrinkles of the film due to softening and whitening due to crystallization occur. There was a problem.

 An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a polyester film for molding which is not only excellent in environmental properties but also excellent in processing characteristics such as moldability, printability and the like. is there. Disclosure of the invention

 An object of the present invention described above is to provide a film which satisfies the following formula (1), comprising polyester A comprising at least two kinds of dalicol components selected from ethylene glycol, butanediol, and propanediol. Achieved by a polyester film characterized in that the crystal melting temperature curve of the film in the DSC heating measurement has a substantially single peak and the melting peak temperature is 230 ° C or higher. Is done. '

 M / P≤1 (1)

 (However, M in the formula represents the concentration of the catalytic metal element remaining in polyester A (milli mol%), and P represents the amount of phosphorus remaining in polyester A (milli mol%).) Best form to do

 In the polyester A of the present invention, as a structural unit of the polyester, a glycol component is selected from ethylene glycol, butanediol, and propanediol in terms of improving moldability, processability, and printability. It is necessary that the polyester contains at least two kinds of components.

Especially in applications where moldability, processability, and printability are important, the polyester A Preferably, 40 to 90 mol% of the polyester component is ethylene glycol. From the viewpoint of improving the following moldability and processability by 100, it is more preferable that 50 to 90 mol% of the glycol component of the polyester A be ethylene glycol, and 60 to 85 mol%. Is particularly preferably ethylene glycol.

 In order to improve moldability and workability at 100 ° C or less, 100 to 60 mol% of the glycol component of polyester A is selected from butanediol and Z or propanediol. More preferably, the glycol is selected from butanediol and / or propanediol, and more preferably, 15 to 40 mol% is butanediol and / or propanediol. Alternatively, glycols selected from propanediol are particularly preferred. Butanediol and butanediol may be used in combination.

 In particular, from the viewpoint of improving moldability, additivity, and printability, it is preferable to include all of ethylene glycol, butanediol, and propanediol as a glycol component. In this case, it is preferable that Χ + Ζ-0 is 0 or more, where X, Υ, and を are the mole percentages of ethylene dalicol, butanediol, and propanediol, respectively.

 Further, other glycol components include, for example, aliphatic glycols such as pentanediol, hexanediol, and neopentyl diol; alicyclic glycols such as cyclohexanedimethanol; bisphenols (bisphenol A, Bisphenol S), 1,3-bis (2-hydroxyethoxy), 1,2-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene, bis [ Aromatic glycols such as 4- (2-hydroxyphenyl) phenyl] sulfone, 2,2-bis (4-; 3—hydroxyethoxyphenyl) propane, hydroquinone and resorcin; diethylene glycol; Polyethylene glycol, polytrimethylene glycol, polytetramethylene glycol, etc. Can be done. The amount of diethylene glycol contained is preferably from 0.1 to 10 mol% from the viewpoint of moldability, curability, and printability, and from 0.3 to 5 from the viewpoint that weather resistance is not deteriorated. Preferably it is mol%.

Examples of the acid component of the polyester A include terephthalic acid, isophthalic acid, Aromatic dicarboxylic acids such as phthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodium sulfoisophthalic acid, and phthalic acid, oxalic acid, succinic acid, and adipic acid And aliphatic dicarboxylic acids such as sebacic acid, dimer acid, maleic acid, and fumaric acid; alicyclic dicarboxylic acids such as cyclohexyne dicarboxylic acid; and oxycarboxylic acid such as P-oxybenzoic acid. Can be. Terephthalic acid, isophthalic acid, adipic acid, and the like can be suitably used in terms of heat resistance, moldability, processability, and printability.

 The polyester A of the present invention is obtained by adding at least two kinds of glycol component units selected from ethylene glycol, butanediol, and propanediol in the polyester A in the course of polymerization to obtain a copolymerized polyester. And a method of blending a plurality of polyesters in an extruder. At this time, a film using a copolymer of polyester and polyester deteriorates in solvent resistance, printability, heat resistance, and the like. Therefore, a film formed by blending a plurality of polyesters is preferable. It is preferable to use a blend of two or more resins selected from the group consisting of polypropylene latex, P.PT (polypropylene terephthalate) and PBT (polybutylene terephthalate). Here, PET, PPT, and PBT include those obtained by copolymerizing the above-mentioned acid component and / or glycol component at a low ratio of 20 mol% or less, more preferably 10 mol% or less, particularly preferably 5% or less. In particular, a blend of PET and PPT is preferred in terms of moldability, whitening resistance, and the like, and particularly preferred is a PET to PPT content of 40 to 90 mol%, and a PPT of 10 to 60 mol%. It is a blended polyester.

 In the polyester film of the present invention, it is necessary that the polyester satisfies the following formula (1) in order to reduce variations in heat resistance, solvent resistance, printability, and quality.

 M / P≤1 (1)

(However, M in the formula represents the concentration of the catalytic metal element remaining in the polyester A (milli mol%), and P represents the concentration of the phosphorus element remaining in the polyester A (milli mol%). )

Here, these metal element and phosphorus element concentrations are It is expressed as the concentration per unit (mol).

 Preferably, MZP is at least 0.001 and less than 1, more preferably at least 0.001 and at most 0.8, particularly preferably at least 0.01 and at most 0.6.

 By controlling M / P≤l, the thermal stability is increased, transesterification of the blended polymer can be suppressed, and a decrease in melting point due to heat treatment can be suppressed. As a result, the characteristics listed above can be improved.

 In the present invention, when producing polyester A, a conventional reaction catalyst and a coloring inhibitor can be used. Examples of the reaction catalyst include an alkaline earth metal compound, a zinc compound, and a lead compound. A compound, a manganese compound, a cobalt compound, an aluminum compound, an antimony compound, a titanium compound, and the like can be used. As the coloring inhibitor, for example, a phosphorus compound can be used. Preferably, it is usually preferable to add an antimony compound, a germanium compound, or a titanium compound as a polymerization catalyst at any stage before the production of the polyester is completed. Examples of such a method include, for example, a method in which a germanium compound is added as it is, a method in which a germanium compound powder is added as it is, and a method in which polyester is used as described in Japanese Patent Publication No. 54-222324. A method in which a germanium compound is dissolved and added to a glycol component as a starting material can be used.

 Examples of the germanium compound include germanium dioxide, germanium hydroxide containing crystal water, germanium tetramethoxide, germanium tetratraoxide, germanium, and germanium alkoxide compounds such as germanium tetrabutoxide, germanium ethylene dalioxide, and germanium. It is possible to use germanium phenoxide compounds such as phenolate and germanium β-naphthrate, and phosphorus-containing germanium compounds such as germanium phosphate and germanium phosphite, and germanium acetate. Among them, germanium dioxide is preferable.

 The antimony compound is not particularly limited. For example, antimony oxides such as antimony trioxide, antimony acetate and the like can be used.

Examples of the titanium compound include, but are not particularly limited to, alkyl titanate compounds such as tetraethyl titanate and tetrabutyl titanate, and titanium and silicon, and zirconium. Composite oxides with an element selected from the group consisting of conium and aluminum can be preferably used.

 The phosphorus compound added as a heat stabilizer to the polyester in the present invention is not particularly limited, but is preferably phosphoric acid, phosphorous acid, phosphoric acid ester, or the like.

 In particular, a phosphorus compound having a molecular weight of 300 or more, particularly preferably 400 or more, is preferably used from the viewpoint of suppressing bleed out during film formation. Examples of the phosphorus compound having a molecular weight of 300 or more include stearyl phosphoric acid, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, and cresyl diphenyl phosphate. Among them, stearyl phosphoric acid is particularly preferred from the viewpoint of suppressing bleed out.

 The content (addition amount) of the phosphorus compound to be added to the polyester A is from 20 to 100 millimol% based on the phosphorus compound in terms of thermal stability and color tone. It is preferably in the range of 90 to 900 millimol%, particularly preferably in the range of 120 to 800 millimol%.

 Further, as a method of adding the phosphorus compound, either a method of adding the compound at the time of polymerization or a method of supplying the compound together with the polymer to the extruder and adding the compound may be used. In general, if a large amount of a phosphorus compound is added during the polymerization, the polymerization reaction will be inhibited. Therefore, it is preferable to supply the polyester with an ordinary polyester in the range of MZP> 1 by adding it to a press machine.

 In the polyester film of the present invention, it is necessary that the melting curve of the film in the DSC temperature rise measurement shows a substantially single peak.

 If the crystal melting curve of the film has two or more peaks, the molecular structure of the copolymer or the mixture is not uniform, so that the variation in elongation is large, and the moldability, The whitening resistance may be poor.

Here, the peak of the crystal melting curve in the present invention is a crystal melting peak caused by a polymer constituting the film, and the film (5 mg) is heated at a temperature of 20 ° C. under a nitrogen atmosphere in a DSC under DSC. This is the minimum point of the endothermic curve obtained from the DSC curve measured at the temperature rate, that is, the point where the differential value becomes zero. In addition, the shoulder peak (minimum point of the peak) with a heat of fusion of 2 J / g or more that partially overlaps with one endothermic curve shall be regarded as an independent crystal melting curve peak. That is, the substance referred to in the present invention The term “single peak” means that there is only a single minimum point of the crystal melting peak having a heat of fusion of 2 J / g or more.

 The peak point temperature of the crystal melting curve of the polyester film according to the present invention needs to be 230 ° C. or higher from the viewpoint of heat resistance. It is more preferably 235 to 260, and particularly preferably 244 to 255 ° C.

 The intrinsic viscosity of the polyester A is preferably 0.5 to 1.5.In particular, in applications where a thin film is required in terms of moldability and processability, the intrinsic viscosity of the polyester A is 0.6 to 1.5. More preferably, it is 3, and particularly preferably, the intrinsic viscosity is 0.7 to 1.0.

 The polyester film of the present invention preferably has an average elongation at break of 800% or more at 80 ° C. in order to improve various moldability and processability. Here, the average elongation at break of the film is defined as the elongation at break in the longitudinal and transverse directions when a film having a width of 10 mm and a length of 100 mm is stretched at 300 mm / min. It is the average value after measuring twice and excluding the maximum and minimum points in each direction. The average elongation at break at 800C is more preferably 900% or more, and particularly preferably 1000% or more and 2000% or less.

 The polyester film according to the present invention contains 1 to 60% by weight of a plasticizer having a molecular weight of 300 or less from the viewpoint of further improving the moldability and processability and improving the flexibility of the film. Is preferred. In particular, from the viewpoint of improving flexibility, it is preferable to include 5 to 60% by weight of a plasticizer having a molecular weight of 300 or less. As the plasticizer, those having a freezing point of 30 ° C. or lower are preferable, more preferably 20 ° C. or lower, and particularly preferably 10 ° C. or lower.

The type of the plasticizer is not particularly limited, but is a compound having a molecular weight of 300 or less. Examples of the type include an adipic acid-based plasticizer, a phosphorus-based plasticizer, a polyether-based plasticizer, and a trimerizer. For example, a nitric acid plasticizer or a phthalic acid plasticizer can be used. These plasticizers are preferably introduced with a functional group-blocking group for suppressing the reaction with polyester A. As the plasticizer used in the present invention, an ester plasticizer is preferable, particularly from the viewpoint of heat resistance and moldability. As the ester plasticizer, those having a hydroxyl value of 0 to 20 (mg / g) are preferable from the viewpoint of heat resistance, and more preferably 0 to 15 (mg / g) is preferred. The acid value is preferably from 0 to 5 (mg / g), and particularly preferably from 0 to 3 (mg / g).

 Examples of the method of adding a plasticizer include a method of adding a patch before or after a polymerization reaction, a method of using a vent-type extruder, and a method of adding a plastic from a screw or a pipe wall using a liquid feed pump. .

 In the present invention, when a polyester B layer is compounded on at least one side of the A layer containing the polyester A as a main component, the plasticizer has a bleed-out resistance, a handling property, a non-adhesive property during processing, or It is more preferable from the viewpoint of providing a new function such as thermal adhesion.

 Layer A containing polyester A as a constituent and layer B containing polyester B as a constituent can be arbitrarily combined. For example, it is possible to composite such as polyester A / polyester B, polyester A / polyester B / polyester A, polyester B / polyester A / polyester B, and the like. At this time, polyester B was laminated on at least one side, especially from the viewpoint of improving the bleed-out resistance, handleability, non-sticking property during processing, and thermal adhesion properties of the plasticizers mentioned above. Polyester AZ polyester B, more preferably polyester B / polyester A / polyester B having polyester B laminated on both sides is preferred. Examples of the acid component of the polyester B include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarbonic acid, diphenyl ethane dicarboxylic acid, and 5-sodium sulfoisophthalic acid. Aliphatic dicarboxylic acids such as aromatic dicarboxylic acids such as phthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, fumaric acid, and cycloaliphatic dicarboxylic acids such as cyclohexin dicarboxylic acid Acids, oxysulfonic acids such as p-oxybenzoic acid and the like can be mentioned. Terephthalic acid, isobutyric acid, adipic acid, and the like can be suitably used in terms of heat resistance, moldability, curability, and printability.

Examples of the glycol component of the polyester B include aliphatic glycols such as ethylene glycol, propandiol, butanediol pentylenediol, hexanediol, and neopentyl alcohol; alicyclic glycols such as cyclohexanedimethanol. Coal; bisphenols (bisphenol A, bisphenol S, etc.), 1,3-bis (2-hydroxyethoxy), 1,2-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene, bis [4- (2- (Hydroxyethoxy) phenyl] sulfone, 2,2-bis (4-J3—hydro-D-ethoxyethoxyphenyl), aromatic glycols such as propane, high'-droquinone, resorcinol; diethylene glycol, polyethylene glycol And polytrimethylene glycol, polytetramethylene glycol, and the like. The amount of diethylene glycol contained is preferably 0.1 to 10 mol% in terms of moldability, processability, and printability, and 0.3 to 5 mol% in that the weather resistance is not deteriorated. %.

 Particularly for applications requiring moldability and workability, the intrinsic viscosity of Polyester B is preferably from 0.5 to 1.5, and more preferably from 0.6 to 1.3. It is particularly preferable that the ratio be 0.7 to 1.0.

 Also, as for polyester B, it is preferable that MP ≤ 1 as in polyester A, and more preferably, the range of M / P is 0.0001 or more and less than 1, and more preferably 0.001. It is at least 0.8 and particularly preferably at least 0.1 and at most 0.6.

 In particular, the thickness of the polyester B layer is preferably 0.1 m or more and 1 mm or less from the viewpoint of improving the resistance to pre-out of the plasticizer, the handling property of the film, and the non-adhesion property during processing. More preferably, it is 1 tfm or more and l mm or less.

 Further, in the present invention, particles may be added to each layer in order to improve the handling and processability of the film.

 Specifically, inorganic particles include wet and dry silica, colloidal silica, aluminum silicate, titanium oxide, calcium carbonate, calcium phosphate, barium sulfate, alumina, myriki, kaolin, clay, and titanium oxide. , Zirconia, and concealed xiapatite can be used.

As the organic particles, various organic polymer particles can be used, and the type may be any type of particles as long as at least a part thereof is insoluble in polyester. Materials for such particles include polyimide, polyamide imide, polymethyl methacrylate, formaldehyde resin, Various materials such as phenolic resin, crosslinked polystyrene, and silicone resin can be used, but vinyl'-based crosslinked polymer particles and crosslinked polystyrene particles that have high heat resistance and are easy to obtain particles with uniform particle size distribution Is particularly preferred.

 The particles are added to polyester A and / or polyester B, and the average particle size of the particles is preferably from 0.01 to 10 m, and especially in applications where processability is important, the average particle size is 0.1. It is preferred to contain particles of up to 5 m. When the particles are added to each layer, the amount of the particles added is preferably from 0.01 to 70% by weight.

 Further, each layer may contain a component imparting low surface energy, such as wax or silicone, and the amount of addition is preferably 0.01 to 1% by weight in each layer.

 From the viewpoint of improving beauty, it is preferable to use a filter for cutting coarse particles and foreign substances of 30 ^ m or less when melt-extruding the thermoplastic composition. It is desirable to use a cutting filter.

 Furthermore, the content of acetoaldehyde in the film is preferably 100 ppm or less, more preferably 5 ppm or less, in order to reduce the odor during molding and processing, and to reduce the odor as a product. It is particularly desirable that the content be 3 O ppm or less.

 The method for lowering the content of case 1 and aldehyde in the film is not particularly limited, but, for example, acetate aldehyde generated by thermal decomposition when producing polyester by a polycondensation reaction or the like. A method of heat treating the polyester at a temperature lower than the melting point of the polyester under reduced pressure or in an inert gas atmosphere, preferably, by heating the polyester at a reduced pressure or in an inert gas atmosphere at a temperature of 150 or more. , Solid-state polymerization at a temperature below the melting point, melt-extrusion using a bent-type extruder, and extrusion in a short time by lowering the extrusion temperature as much as possible when melt-extruding a polymer. Can be used.

The method for producing the polyester film according to the present invention is not particularly limited. For example, when polyester A containing particles of polyethylene terephthalate, polypropylene terephthalate, or polybutylene terephthalate is mixed, the polyester A After the ester mixture and, if necessary, the phosphorus compound are dried or dried, the mixture is fed to a single-screw or twin-screw melt extruder, extruded in a sheet form from a slit die, and placed between nip rolls. Drop it, bring it into close contact with the casting drum, cool and solidify to obtain an unstretched sheet. At this time, it is preferable to reduce the diameter of the nip roll and / or to increase the roll temperature in producing a film of 150 m or less. For reducing the diameter of the nipple, the diameter is preferably 400 mm or less, and particularly preferably 300 mm or less. The increase in the roll temperature is preferably from 40 ° C to 150 ° C, more preferably from 50 ° C to 140 ° C. The resulting sheet may be roughened to make the film non-adhesive, and the obtained sheet is rolled into a roll sheet to obtain a product.

 In addition, close contact with the casting drum by the electrostatic application method can be more preferably used in that the flatness during the heating process is maintained because cooling can be stably performed.

 In particular, in applications where emphasis is placed on moldability and processability, it is preferable to produce an unstretched film as described above.

 On the other hand, in applications where heat resistance is important, the unstretched sheet is stretched and heat-treated in the longitudinal direction and width or width direction of the film, as necessary, to obtain a film having a desired breaking elongation. There is a way. Preferably, the tenter method is used in terms of film quality.Long; sequential biaxial stretching method in which the film is stretched in the hand direction and then stretched in the width direction. Simultaneously, the film is stretched almost simultaneously in the longitudinal and width directions. A biaxial stretching method is desirable. The stretching ratio is preferably 1.5 to 5.0 times, and more preferably 1.5 to 4.0 times in each direction. Either the stretching ratio in the longitudinal direction or the stretching direction in the width direction may be increased, or may be the same. The stretching speed is preferably 100% / minute to 100% / minute, and in particular, the film can be formed at a longitudinal stretching speed of 300% / minute or less. preferable. The stretching temperature can be any temperature as long as it is 100 ° C. or more and 150 ° C. or less, but is preferably glass transition temperature + 20 ° C. to 60 ° C.

Further, after this, the film is subjected to a heat treatment. This heat treatment can be performed by any conventionally known method such as in an oven, on a heated roll, or the like. The heat treatment temperature can be any temperature from 60 ° C. to 250 ° C., but is preferably from 150 ° C. to 240 ° C. The heat treatment time can be arbitrarily set, but is 0.1 to 60 seconds. Preferably, it is between 1 and 20 seconds.

 The heat treatment may be performed while relaxing the film in the longitudinal direction and the Z or width direction. Further, re-stretching may be performed once or more in each direction, and then heat treatment may be performed.

 The thickness of the polyester film according to the present invention is preferably from 10 to 200 Om, more preferably from 20 to 100 μπι from the viewpoint of moldability and workability. You. '

 The polyester film of the present invention may be subjected to a corona discharge treatment, a coating treatment, etc. before or after winding, if necessary, in order to improve processability and adhesiveness. At this time, the surface energy is preferably 40 to 6 OmN / m, more preferably 4,5 to 6 OmN / m.

The polyester film according to the present invention is preferably used as an unstretched film when emphasis is placed on moldability and workability, but when uniaxially or biaxially stretched is used, the formability and processability are preferably used. In terms of point, the plane orientation coefficient is preferably in the range of 0.03 to 0.14. In particular, in applications where film formability and heat resistance are required, the plane orientation coefficient is preferably from 0.3 to 0.145, more preferably from 0.04 to 0.14, particularly preferably from 0.04 to 0.14. Preferably it is 0.05 to 0.13. Here, the plane orientation coefficient, the longitudinal refractive index of the film n _MD, in the width direction refractive index n _TD of the film, the thickness direction refractive index of Fi Lum upon the n _ZD, plane orientation coefficient fn = (n MD + n TD) / 2 — expressed as n _ZD .

 The polyester film according to the present invention is used for molding, processing, and processing of a single material, a non-metallic material, or a laminated structure with a metal material because of its excellent moldability, processability, and printability. The purpose of use is not particularly limited, but when used in a laminate, it is preferable that the nonmetallic material is paper, nonwoven fabric, glass, or a polymer material in terms of reducing the weight of the final product. On the other hand, in applications where the strength of the material is required, it can be used in a configuration in which this film is laminated with a metal or glass-reinforced polymer.

The polyester film according to the present invention is partially melted by heat, The film or other material of the present invention may be provided with an adhesive layer in advance. Further, an adhesive layer, a printing layer, and the like may be formed between the laminated structure and another material.

 Forming and processing methods include laminating, vacuum forming, air pressure forming, vacuum air forming, drawing, bending, or a combination or combination of these and other processing methods. The molding and processing methods are not particularly limited.

 When used alone, it may be subjected to one or more molding processes such as vacuum forming, air pressure forming, vacuum pressure forming, draw forming, bending forming, overhang forming, etc. There is no particular limitation.

【Example】

 Hereinafter, the present invention will be described in detail with reference to examples. Various properties were measured and evaluated by the following methods.

 (1) Intrinsic viscosity of polyester

 The polyester was dissolved in orthochlorophenol and measured at 25 ° C.

(2) Catalyst metal in polyester

 The amount of phosphorus was determined by fluorescent X-ray analysis. The quantification was performed by preparing a sample containing a certain amount of each metal element and preparing a calibration curve.

 (3) Melting point of polyester film

 5 mg of a polyester film sample was measured using a differential scanning calorimeter RDC 220 manufactured by Seiko Denshi Kogyo Co., Ltd. in a nitrogen atmosphere at _30 for 5 minutes, and then at a heating rate of 20 minutes in 20 minutes. The minimum point of the endothermic curve obtained from the DSC curve at that time (ie, the point where the differential value becomes 0) was defined as the crystal melting peak temperature. In addition, the shoulder peak (minimum point of the peak) with a heat of fusion of 2 J / g or more that partially overlaps one endothermic curve is also regarded as an independent crystal melting curve peak. For the laminated film, 5 mg of polyester of each layer was sampled with one blade, and the measurement was performed in the same manner.

 (4) Refractive index of film

Measured with Abbe refractometer using sodium D line (wavelength 589 nm) as light source did. Plane orientation coefficient is, the longitudinal refractive index n _MD of the film, the width direction refractive index n _TD of Fi Lum, when the thickness direction refractive index of the film was n _ZD, plane orientation coefficient fn = (n MD + n TD) / 2 — expressed in _nD .

 (5) Average particle size.Cut the cross section of the film into ultra-thin sections, photograph them with a transmission electron microscope at a magnification of about 500-2000, and disperse them in polyester A. The circular equivalent diameter of the particles was measured, and the average particle diameter was determined.

 (6) Average elongation at break.

 The measurement was performed at 80 ° C using a Tensilon (tensile tester). In the measurement, the film was kept at the measurement temperature for 30 seconds, and the elongation at break (%) in the film longitudinal direction and the width direction was 1 for each of a tensile speed of 300 mmZmin, a width of 10 mm, and a sample length of 5 Omm. Zero points were measured and the average was determined.

 (7) Compressibility

 The temperature was changed from 80 to 13 O :, and the moldability was judged with a compressed air molding machine. The state at the time of molding under the best temperature conditions was determined as follows.

 :: The corner was sharply formed, and the thickness after molding was uniform.

 ：: The corners were slightly round, but the thickness after molding was uniform.

 Δ: The corner was slightly rounded, and the thickness after molding was slightly uneven.

 X: The thickness after molding was uneven, wrinkled or whitened.

 (◎, 〇, △ passed, X failed)) '

 (8) Printability

 A solvent-based ink containing ethyl acetate and toluene was gravure coated, and the appearance after drying at 80 was confirmed.

 ◎: No whitening, good beauty

 〇: Some whitening is observed, but there is no beauty problem

 Δ: Whitening is observed, and beauty is reduced

 X: Large whitening and large change in appearance · (◎, △, △ passed, X failed)

(9) Embossing The polyester film of the present invention and a commercially available biaxially-stretched PET film (“Lumirror” manufactured by Toray Industries, Inc., S type, 75 mm) are adhered with a urethane-based adhesive using ethyl acetate as a solvent. After drying at 80 ° C, the polyester film side of the present invention is heated by roll heating (100 ° C) and immediately before heating by a condensing type radiation jet, and embossed roll (50 m height unevenness) After passing through, the mixture was cooled with a cooling roll (40 T). The radiation heating setting was changed, and the evaluation was performed in the best condition. The embossability of the obtained film was determined as follows. The beauty was judged based on no color change, no wrinkles and no glare.

 A: The uneven shape of the embossing roll is favorably formed on the film side, both large and small. Good beauty.

 〇: The part with large unevenness of the embossing roll is favorably formed on the film side. Almost no change in beauty.

 Δ: The unevenness of the embossing roll is formed on the film side, but the unevenness is slightly shallow. A change in beauty is also observed.

 X: The concave shape of the embossing roll is formed on the film side, but the unevenness is shallow and the change in beauty is large.

 (◎, 〇, △ passed, X failed.)

 (10) Whitening resistance

 The film was heat-treated in a hot-air oven at 110 ° C for 3 minutes to determine the whitening property.

 ◎: No whitening, good transparency.

 〇: Some whitening is observed, but transparency is good.

 Δ: No problem in use, but noticeable whitening is observed.

 X: Large white and opaque. '.

(◎, 〇, △ passed, X failed.)

 (1 1) Thermal stability

5 mg of a polyester film sample was collected, and using a differential scanning calorimeter RDC 220 manufactured by Seiko Denshi Kogyo Co., Ltd., under nitrogen atmosphere, _30 ° (: up to 280 ° 〇, 20 / min. (1st Run), hold at 280 ° C for 20 minutes, Thereafter, the mixture was rapidly cooled to 130 ° C with liquid nitrogen, and then measured again at a temperature rising rate of 20 ° CZ to 280 ° C (2nd Run).

 For the laminated film, the measurement is performed without separating each layer, and the melting point Tm1 measured by Ist Run and the melting point Tm2 measured by 2nd Run are substantially single peaks. The melting point difference Δ Τπι (= Tm l _ Tm 2) was determined.

 ◎: ΔT m≤ 7

 〇: 7 <Δ T m ≤ 15

 X: 15 <Δ T m

 (◎, 合格: pass, X: reject.) Details of polyester used in Examples are described below. Table 1 shows a list of these and the amounts of catalytic metal elements, phosphorus elements, and intrinsic viscosities.

 [PET (1) (polyethylene terephthalate with high phosphorus content)]

 A manganese catalyst was added to dimethyl terephthalate and ethylene glycol to perform a transesterification reaction, followed by antimony trioxide as a polymerization catalyst and phosphoric acid as a heat stabilizer, followed by a polycondensation reaction for 6 hours. Composition PET

(1) was obtained (catalyst metal element amount: 70 millimol%, phosphorus element amount: 100 millimol%, intrinsic viscosity 0.71).

[P E T (2) (usually polyethylene terephthalate)]

 A manganese catalyst was added to dimethyl terephthalate and ethylene glycol to perform a transesterification reaction, followed by antimony trioxide as a polymerization catalyst and phosphoric acid as a heat stabilizer, followed by a polycondensation reaction for 4 hours. Composition PET

(2) was obtained (catalyst metal element amount: 70 millimol%, phosphorus element amount: 20 millimol%, intrinsic viscosity 0.73).

[P P T (Polypropylene terephthalate)]

Dimethyl terephthalate, 1,3-propylene glycol, titanium as catalyst After a transesterification reaction with the addition of a polyester catalyst, phosphoric acid was added as a thermal stabilizer and a polycondensation reaction was carried out to obtain a polyester composition PPT (catalytic metal element content: 13 mol%, Element amount: 3 millimol%, intrinsic viscosity 0.90).

[PP TZ I ^{1 Q} (isophthalic acid 10 mol% copolymerized PPT)]

According to the synthetic method of PPT, isophthalic acid copolymerization amount to obtain a 1 0 mole% copolymerized poly ester composition 'PPT / I ^{1 Q} (catalytic amount of metal element: 1 3 Mi Rimoru%, Li emissions based elementary charge: 3 millimol%, intrinsic viscosity 0.85).

[PBT (polybutylene terephthalate)]

 A transesterification reaction was performed by adding a titanium catalyst as a catalyst to dimethyl terephthalate and 1,4-butanediol, and then a polycondensation reaction was performed by adding phosphoric acid as a heat stabilizer to obtain a polyester composition PBT. (Amount of catalytic metal element: 50 millimol%, amount of phosphorus element: 30 millimol%, intrinsic viscosity 1.0).

[PET / CHDM ³⁰ (cyclohexanediethanol ³⁰ mol% copolymerized PET)]

Dimethyl terephthalate, ethylene glycol and cyclohexane dimethanol were used to obtain ³ ° of PE TZC HDM (catalyst metal element amount: 80 millimol%, phosphorus element element: 80 millimol) %, Intrinsic viscosity 0.75).

[PIB (isophthalic acid copolymerized polyester)]

Copolymerization of 10 mol% of terephthalic acid, 90 mol% of isophthalic acid, 90 mol% of ethylene glycol, 2 mol% of diethylene glycol, and 8 mol% of 1,3-bis (2-hydroxybenzene) benzene Polyester PIB (catalyst metal element content: 70 millimol%, phosphorus element content: 20 millimol%, intrinsic viscosity 0.8) was synthesized. Catalyst metal amount Phosphorous element amount

 Polyester Catalyst metal M P Intrinsic viscosity

 , O ノ ヽ

 (:; Remol% J (:; re "6 re% ■)

 PET (1) Mn, Sb 70 100 0.71

 PET (2) Mn, Sb 70 20 0.73

 PPT Ti 13 3 0.90

PPT / I ¹⁰ Ti 13 3 0.85

 PBT Ti 50 30 1.00

PET / CHDM ³⁰ Mn, Co 80 80 0.75

 PIB Mn, Sb 40 20 0.80

[Preparation of particle-containing PET]

 Crosslinked polystyrene particles (average particle diameter 6 ^ m), silicone particles (average particle diameter 5 m), and aggregated silica (average particle diameter 1.7 aim) were prepared. The above-mentioned PET (1) and PET (2) were provided in two vacuum vents (5 Torr) in a twin-screw extruder and melted, and particle-containing PET added with 5% by weight of each was obtained.

Hereinafter, examples of film formation of the film of the present invention and characteristics thereof will be described. Contents not described in the text in terms of film composition, characteristics, etc. are as shown in Tables 2-6. ''

[Example 1]

The PPT, Ρ Ε 粒子 and particle-containing PET obtained as described above were chip-blended so as to have the composition shown in Table 2. Then, it is vacuum-dried at 150 ° C, fed to an extruder (280 ° C) and melted, discharged from a die (270 ° C) by a conventional method. It was cooled and solidified on a drum (25 ° C) to obtain a 100 m unstretched film. Table 2 shows the physical properties, moldability, printability, and processability of the obtained film. As can be seen from Table 2, the moldability, printability, and workability were excellent. [Example 2]

 The composition of the particles and the polyester were mixed as shown in Table 2, and during the melt extrusion, stearyl phosphoric acid (ADK STAB AX-71, manufactured by Asahi Denka Kogyo Co., Ltd., molecular weight 490) was weighed in an undried state with a feeder. Then, a certain amount of the polyester mixture is fed to a twin-screw extruder (having three vacuum vents (5 Torr) in the zone after melting the polyester) at a feeder, and melt extrusion is performed at 270 ° C. The polymer that came out of the slit from the base (270 ° C) was cast on a nip roll (diameter 250 mm) with a cooling drum at 50 ° C. Otherwise in the same manner as in Example 1, a 100 / zm unstretched film was obtained. Particularly, the thermal stability was improved.

[Example 3]

 Polyester and stearyl phosphoric acid were mixed to obtain the composition shown in Table 2, and polyethylene glycol dibenzoate (molecular weight: 600) was added as a plasticizer in a 5% by weight liquid state, followed by cooling during casting. A film was formed in the same manner as in Example 2 except that the drum temperature was changed to 10 ° C. In particular, the workability was improved.

[Example 4]

 The addition amount of the plasticizer used in Example 3 was set to 10% by weight, and the mixing amount of polyester and stearyl phosphoric acid was changed so as to have the composition shown in Table 3. Further, the same as Example 3 except that the composite structure was B / AZB (composite ratio: 1: 10: 1) and the polyester of the B layer was composited with the polyester having the same composition as that used in Example 1. To give a film of 60 μm. The obtained film was flexible even at room temperature, and was particularly excellent in printability.

[Example 5]

The addition amount of the plasticizer used in Example 3 was set to 5% by weight, the particles used for the layer B were changed to aggregated silica, and the composite structure was changed to BZA / B (composite ratio: 1: 10: 1). In addition, the casting method was changed to a method of cooling and solidifying with a mirror cooling drum (10 ° C) while applying static electricity. Otherwise in the same manner as in Example 2, an unstretched film was obtained. Profit The obtained unstretched film is subjected to a longitudinal stretching temperature of 80 ° C, a longitudinal stretching ratio of 3.1 times, a transverse stretching temperature of 100, a transverse stretching ratio of 2.8 times, and a heat treatment temperature of 230 ° C. Obtained. Although the moldability of the film was lowered, the printability was excellent.

[Example 6]

 Polyester and stearyl phosphoric acid were mixed so as to have the composition shown in Table 3, and the casting method was changed to the electrostatic application method and cooled and solidified with a mirror cooling drum at 10 ° C. An unstretched film of 100 m was obtained in the same manner.

[Example 7]

In Example 1, except that the instead of ^PPT Ρ Ρ Τ Ζ Ι ¹ Π is to obtain an unstretched film of 1 0 0 m in the same manner as in Example 1. In particular, the moldability was improved.

[Example 8]

 An unstretched film was obtained in the same manner as in Example 6 except that polyester and stearyl phosphoric acid were mixed so as to have the composition shown in Table 4, and that the plasticizer used in Example 3 was used at 10% by weight. The obtained unstretched film was biaxially stretched at a longitudinal stretching temperature of 75 ° C, a longitudinal stretching ratio of 3.0 times, a transverse stretching temperature of 85 ° C, a transverse stretching ratio of 2.8 times, and a heat treatment temperature of 160 ° C. A stretched film was obtained. Regarding the properties of the obtained film, the printability was lower than that of the film obtained in Example 5, but the flexibility at room temperature became better.

[Example 9]

The polyester was changed to have the composition shown in Table 4, the composite composition was changed to B / AZ B (composite ratio: 1: 10: 1), and the mirror cooling drum (10 ° C )), An unstretched film of 100 zm was obtained in the same manner as in Example 2 except that the system was cooled and solidified. The characteristics of the film obtained by laminating polyester B were excellent in solvent resistance and excellent in printability. ' [Example 10] '

 Polyester and stearyl phosphoric acid are mixed so as to have the composition shown in Table 5, and the composite composition is B / A / B (composite ratio: 1: 10: 1). An unstretched film of 100 m was obtained in the same manner as in Example 2 except that the system was cooled and solidified with a drum (100 ° C.). The printability was slightly inferior to Example 9, but the moldability and processability were equally good.

[Comparative Example 1]

 PET (1) and PET containing particles were blended so as to have the composition shown in Table 5, and a film was formed in the same manner as in Example 2. As a result, thermal workability such as embossability was greatly reduced.

[Comparative Example 2]

Using the PET / CHDM ³ °, to obtain an unstretched film (particles added PE TZ C HD M ³ ° also be used to create separately) In a similar manner to Example 1 from a thickness of 6 0 im. It was an amorphous polyester film having no melting peak in the crystal melting temperature curve, and was very poor in solvent resistance. As a result, as shown in Table 5, the printability was greatly reduced.

[Comparative Example 3]

 A film was formed in the same manner as in Example 1 except that the polyester and stearyl phosphoric acid were mixed so as to have the composition shown in Table 6, and the extruder temperature was set at 270 ° C. In the obtained film, the melting points of PET and PBT appeared, that is, substantially no single peak was observed. The properties of the obtained film were inferior to whitening resistance, pressure forming property, embossability, and the like.

[Comparative Example 4]

Polyester was mixed so as to have the composition shown in Table 6, and the others were formed according to the method of Example 2. The obtained film was particularly poor in heat stability and printability. [Comparative Example 5]

 Polyester was used as a blend of PPT and PBT according to the composition shown in Table 6, and a film was formed according to the method of Example 2 except for the above. Polyester A had a melting point of 230 ° C or less, and was inferior in heat stability, whitening resistance, and printability.

Example 1 Example 2 Example 3 Polymer type PET (1), PPT PET (2), PPT PET (2), PPT acid component (mol%) TPA100 TPA100 TPA100

 Glycol component (mol EG78, DEG2, PG20 EG58, DEG2, PG40 EG78, DEG2, PG20

 Catalyst metal M (mmol%) Ti, Mn, Sb Z58 Ti, Mn, Sb Z48 Ti, Mn, Sb / 58

Ding P (mmol ^0/0) 80 580 580 Le M / P (I) 0.74 0.08 0.10

 A

 Melting peak temperature (° c) 247 251 250

 A Intrinsic viscosity 0.74 0.76 0.71 layer Particles Cross-linked polystyrene Silicone Cross-linked polystyrene Average particle size (m) 6.0 5.0 6.0 6.0 Particle addition amount (weight 0.5 0.3 0.4 0.4 Plasticizer addition amount (% By weight) ― '― 5 One polymer type ― ― One point ― One point

 "J acid

 X Glycol — 11 Catalytic metal M (mmol%)

 亍

P (mmol ⁰ / o)

 Le

 B M P (—)

 Melting peak temperature (° c)

 B

 Intrinsic viscosity

 — 'Particles

 Average particle size (m)

 Particle addition amount (% by weight)

 Laminated structure Single layer Single layer Single layer Average elongation at break (%) at 80 ° C 920 890 1100 Plane orientation coefficient (1) 0 0 0 Thermal stability 〇 ◎ ◎

 Whitening resistance O 〇 o

 Compressed air formability ◎ ◎ ◎

 Printability 〇 〇 0

Embossability 〇 〇 © Table 3 Example 4 Example 5 Example 6 Polymer type PET (2), PPT PET (2), PPT PET (2), PBT PO acid component (mol%) TPA100 TPA100 TPA100

■ J Glycol component (mol%) EG78, DEG2, PG20 EG78 DEG2 PG20 EG83, DEG2, BG15 Catalyst metal (millimol%) Ti Mn, Sb No 58 Ti, Mn, Sb / 58 Ti, Mn, Sb / 66 亍 P (mmol ⁰ / o) 580 580 100 Le M / P 0.10 0.10 0.58

A

 Melting peak temperature (° C) 250 250 249

A Intrinsic viscosity 0.71 0.72 0.72

 Particles-Crosslinked polystyrene Average particle size (jUm)--6.0 Particle addition amount (wt%)-0.5 Plasticizer addition amount (wt%) 105-Polymer type PET (1), PPT PET (1), PPT u acid TPA100 TPA100

X Glycol EG78 DEG2 PG20 EG78 DEG2 PG20 ― S catalytic metal (mmol%) Ti, Mn, Sb No 58 Ti, Mn, Sb No 58

P (mmol ^0/0) 80 80

 Le-

 B M / P (one) 0.73 0.73 ―

 Melting peak temperature (° C) 247 247

B

 Intrinsic viscosity 0.74 0.74 One layer

Particles Cross-linked polystyrene Agglomerated silica 1 Average particle diameter () m) 6.0 1. Particle addition amount (% by weight) 0.5 0.1-Laminated structure Composite (BZAZB) Composite (BZAZB) Single layer Average breakage Elongation (%) at 80 ° C 1200 410 900 Plane orientation coefficient (1) 0 0.09 0 Thermal stability 白 Whitening resistance Δ ◎ Δ Compressed air formability 〇 〇 © Printability ◎. ◎ 〇 Embossability 〇 ◎ Table 4 Example 7 Example 8 Example 9 Polymer Type PET (1), PPT / I 10 PET (2), PBT PET (2), PPT Po acid component (mol%) TPA98, IPA2 TPA100 TPA100 ■ J glycol component (mol ^{0/0) EG78, DEG2,} PG20 EG68, DEG2, BG30 EG78 DEG2 PG20

X

■ χ Catalyst metal M (mmol%) Ti, Mn, Sb No 58 Ti, Mn, Sb / 62 Ti, Mn, Sb / 58 Te P (mmol ⁰ / o) 60 580 580 m M / P (-) 0.92 0.11 0.10

A

 Melting peak temperature (° C) 251 249 250

A Intrinsic viscosity 0.68 0.72 0.72 layer Particles • Crosslinked polystyrene Agglomerated silica

 Average particle size (im) 6.0

 Particle addition amount (% by weight) 0.5 0.1-Plasticizer addition amount (% by weight) 10

 Polymer type PET (1), PIB PO ― ― IPA45 TPA55 'J acid

 X Glycol EG90, DEG2, BHEB8 Catalyst metal / M (mmol%) Ti, Mn, Sb Z55 亍

P (mmol ⁰ / o) 60 Le

 B M P (—) 0.92

 Melting peak temperature (° C) 240

B

 Layer Intrinsic viscosity 0.75

 Particles Crosslinked polystyrene Average particle size (jt / m) 6.0 Particle addition amount (% by weight) 0.5 Multilayer structure Single layer Single layer composite (BZAZB) Average elongation at break (%) at 80 ° C 1120 430 950 Plane Orientation Kagyu (-) 0 0.09 0 Thermal stability 〇 ©

Whitening resistance '◎ ◎ ◎ Compressed air formability © 〇 ◎ Printability 〇 O ◎ Embossability © 〇 ◎ Table 5

 Potesulpo (H Sulli A B B

Example 1 0 Comparative example 1 Comparative example 2 Polymer type PET (2), PPT PET (1) PET / CHD 30 Acid component (mol%) TPA100 TPA100 TPA100 Glycol component (mol%) — EG78 DEG2 PG20 EG98 DEG2 EG70 CHDM30 Catalyst Metal ZM (mmol <<) Ti, Mn, Sb / 58 Mn, Sb 70 Mn, Co 80 P (mmol ⁰ / o) 580 100 80

Μ, Ρ (—) 1 0.10 0.70 1.00 Melting peak temperature (° C) 250 254

A Intrinsic viscosity 0.72 0.69 0.72 Particles Agglomerated silica Silicone Average particle size (; Wm) 1.7 5.0 Particle addition amount (wt%) 0.2 0.25 Plasticizer addition amount (weight ^D / o)

 Polymer type PETC 1),

PET / CHDM ³

 TPA100

 Glycol EG78 DEG2 CHDM15I

 Catalyst metal M (mmol%) Ti, Mn, Sb / 75

P (mmol ^0/0) 90

 M / P (one) 0.83

 Melting peak temperature (° C) 247

 Intrinsic viscosity 0.74

 Particles Cross-linked polystyrene

 Average particle size (m) 6.0

 Particle addition amount (% by weight) 0.5

Laminated structure Composite (B AZB) Single layer

Average elongation at break (%) at 80 ° C 1 100 840 930 Plane orientation coefficient (-) 0 0 0 Thermal stability ©

Whitening resistance ◎ o ◎ Compressibility ◎ Δ Δ Printability 〇 〇 X Embossability © X Δ Table 6 Comparative Example 3 Comparative Example 4 Comparative Example 5 Polymers PET (2), PBT PET (2), PPT PPT, PBT PO acid component (mol%) TPA100 TPA100 TPA100

■ J'Glycol component (mol%) EG48 DEG2 BG50 EG78 DEG2 PG20 BG80 PG20 Catalyst metal M (millimol%) Ti, Mn, Sb / 58 Ti, Mn, Sb 58 Ti / 43

Te P (mmol ⁰ / o) 580 16 25 le M / P (I) 0.10 3.63 1.72

A

 Melting peak temperature (¾) 226, 252 243 220

A Intrinsic viscosity 0.74 0.72 0.85 layer Particles Crosslinked polystyrene Crosslinked polyester. Polystyrene Crosslinked polystyrene Average particle size (; Um) 6.0 6.0 6.0 Particle addition amount (% by weight) 0.4 0.5 0.5 0.5 Plasticizer addition amount (% by weight)

 Polymer type

 Acid-one-u

 X Glycol Catalyst metal ZM (mmol%) ― ― ― 亍

 P (mmol%)

 B M / P (I)--I Melting peak temperature (° C)-I

B

 Intrinsic viscosity

Particles ― ― Average particle diameter (j «m) Amount of added particles (% by weight) 1 ¹ ― ― Laminated structure Single layer Single layer Single layer Average elongation at break (%) at 80 ° C 750 950 900 Plane orientation Coefficient (1) 0 0 0 Thermal stability XX Whitening resistance X 〇 X Compressed air formability X 〇 O Printability 〇 XX Embossability X 〇 〇 The abbreviations in the table are as follows

 PET (1) Polyethylene terephthalate with high phosphorus content

P E T (2) Normal polyethylene terephthalate rate

P P T Polypropylene terephthalate

PPT / I ^{1 D} : Isofluoric acid 10 mol copolymer PPT

P B T ': Polybutylene terefu rate

PET / C HDM ³ . : Cyclohexane dimethanol 30 mol copolymer PETPIB: Isophthalic acid copolymer polyester

 E G: Ethylene glycol

 Two

 P G: Propanediol (1, 73-propanediol)

 D E G: Diethylene glycol

 B G: Butanediol (1,4-butanediol) ''

Industrial applicability

 The polyester film of the present invention has excellent moldability, processability, and printability. Can be suitably used as a process film.

Claims

The scope of the claims

 1. Polyester A composed of at least two types of glycol components selected from ethylene glycol, butanediol, and propanediol is a component, and the crystal melting temperature curve of polyester A in DSC temperature measurement is substantially A polyester film having a single peak, a melting peak temperature of 230 ° C. or higher, and satisfying the following formula (1).

 M / P≤ 1 (1)

 (However, M in the formula represents the concentration of the catalytic metal element remaining in polyester A (milli mol%), and P represents the amount of phosphorus remaining in polyester A (milli mol%).)

2. The polyester film according to claim 1, wherein the polyester compound contains 20 to 100% by mole of a phosphorus compound in the polyester A.

3. The polyester film according to claim 2, wherein the molecular weight of the phosphorus compound is 300 or more.

4. The polyester film according to claim 1, wherein the polyester A is composed of 40 to 90 mol% of polyethylene terephthalate, and 10 to 60 mol of polypropylene. '

5. The polyester film according to claim 1, wherein the polyester A contains 1 to 60% by weight of a plasticizer having a molecular weight of 300 or less.

6. A laminated polyester film obtained by laminating polyester B on at least one surface of the polyester film according to any one of claims 1 to 5.