KR101848724B1 - Biaxially oriented polyester film for molding - Google Patents

Abstract

A film which is excellent in moldability and dimensional stability and which can be used for embedding in various molding members by performing molding. The stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 占 폚 is 5 to 60 MPa, respectively, and the storage modulus at 80 占 폚 in the film longitudinal direction and the transverse direction is at least 2001 MPa And a storage elastic modulus in a longitudinal direction and a transverse direction of the film at 180 占 폚 is from 41 MPa to 400 MPa.

Description

[0001] Description [0002] BIAXIALLY ORIENTED POLYESTER FILM FOR MOLDING [0003]

The present invention relates to a biaxially oriented polyester film which is particularly suitably used in molding processing.

In recent years, as environmental consciousness has increased, there has been an increasing demand for coatings and plating substitutes that do not contain solvents in construction materials, automobile parts, mobile phones, and electric appliances, and the introduction of a method of using a film is progressing.

There are several proposals as a polyester film for molding used in such a decorating method. For example, there has been proposed a polyester film for molding that defines a specific molding stress at room temperature (see, for example, Patent Document 1).

Further, a polyester film for molding that defines molding stress and storage elastic modulus at a specific temperature has also been proposed (see, for example, Patent Document 2).

Further, a polyester film for molding which defines a storage elastic modulus in a wide temperature range has also been proposed (for example, see Patent Document 3).

Japanese Patent Application Laid-Open No. 2001-347565 Japanese Patent Application Laid-Open No. 2005-290354 Japanese Patent Application Laid-Open No. 2008- 162220

However, the film described in Patent Document 1 is not designed as a film which is not sufficiently satisfactory in moldability and which is also considered in terms of dimensional stability.

Further, the film described in Patent Document 2 is a film which is insufficient in dimensional stability due to insufficient dimensional stability at a processing temperature of the film of about 80 캜, which is poor in processability.

The film described in Patent Document 3 exhibits a low storage elastic modulus in a wide temperature range and therefore is excellent in moldability but is not sufficient in terms of dimensional stability and does not exhibit satisfactory heat resistance.

SUMMARY OF THE INVENTION An object of the present invention is to overcome the problems of the prior art described above. That is, it is an object of the present invention to provide a biaxially oriented polyester film for molding which is excellent in moldability, dimensional stability, heat resistance and appearance, and can be suitably used for various molding members by performing molding.

In order to solve these problems, the gist of the present invention is that the stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 DEG C is 5 to 60 MPa Is a biaxially oriented polyester film for molding having a storage elastic modulus in a film longitudinal direction and a transverse direction of not less than 2001 MPa and not more than 4000 MPa respectively and a storage elastic modulus in a film longitudinal direction and a transverse direction at 180 캜 of not less than 41 MPa and not more than 400 MPa.

(Effects of the Invention)

The biaxially oriented polyester film for molding of the present invention is molded by various molding methods such as vacuum molding, pressure molding, vacuum compression molding, and injection molding with in-mold molding because molding stress in the molding temperature range is low. In addition, since the storage elastic modulus in the processing temperature range is within a specific range, edible materials can be edited by printing, vapor deposition or the like because of excellent dimensional stability in the processing step of coating, laminating, printing, Temperature property, and exhibits excellent surface properties even after molding and has excellent color appearance. Therefore, it is excellent in appearance, for example, in building materials, mobile devices, electric appliances, automobile parts, And the like can be preferably used.

The polyester constituting the biaxially oriented polyester film for molding of the present invention is a generic name of a polymer compound having an ester bond as a principal bond in the main chain. The polyester resin is usually obtained by polycondensation reaction of a dicarboxylic acid or a derivative thereof and a glycol or a derivative thereof.

In the present invention, at least 60 mol% of glycol units constituting the polyester are structural units derived from ethylene glycol from the viewpoints of moldability, appearance, heat resistance, dimensional stability and economical efficiency, and 60 mol% or more of dicarboxylic acid units are terephthalic acid Derived structural units. Herein, the dicarboxylic acid unit (structural unit) or the diol unit (structural unit) means a divalent organic group excluding a portion removed by polycondensation, and is represented by the following general formula.

Dicarboxylic acid unit (structural unit): -CO-R-CO-

Diol unit (structural unit): -O-R'-O-

(Wherein R and R 'are divalent organic groups)

The same applies to the meaning of units (structural units) relating to carboxylic acids or alcohols having three or more valences such as trimellitic acid units and glycerin units, and derivatives thereof.

Examples of the glycol or derivative thereof to be used in the present invention include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, , Aliphatic dihydroxy compounds such as 1,6-hexanediol and neopentyl glycol, polyoxyalkylene glycols such as diethylene glycol, polyethylene glycol, polypropylene glycol and polytetramethylene glycol, 1,4-cyclohexanedimethanol , Alicyclic dihydroxy compounds such as spiroglycols, aromatic dihydroxy compounds such as bisphenol A and bisphenol S, and derivatives thereof. Of these, 1,3-propanediol, 1,4-butanediol, neopentyl glycol and 1,4-cyclohexanedimethanol are preferably used from the viewpoints of moldability and handleability.

As the dicarboxylic acid or derivatives thereof to be used in the present invention, there may be mentioned, in addition to terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfone dicarboxylic acid Aromatic dicarboxylic acids such as dicarboxylic acid, diphenoxyethane dicarboxylic acid and 5-sodium sulfone dicarboxylic acid, aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, dimeric acid, maleic acid, Cyclohexanedicarboxylic acid and the like, oxycarboxylic acids such as paraoxybenzoic acid, and derivatives thereof can be mentioned. Examples of derivatives of dicarboxylic acids include dimethyl terephthalate, diethyl terephthalate, terephthalic acid 2-hydroxyethyl methyl ester, dimethyl 2,6-naphthalenedicarboxylate, dimethyl isophthalate, dimethyl adipate, diethyl maleate , Dimethyl dimer acid and the like. Of these, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and esterified products thereof are preferably used from the viewpoints of moldability and handleability.

From the standpoint of moldability, the biaxially oriented polyester film for molding according to the present invention needs to have a stress (F100 value) at 100% elongation in a film longitudinal direction and a width direction at 150 DEG C of 5 to 60 MPa, respectively. Examples of the molding method of the molded member include a heat molding method such as vacuum molding, pressure molding, vacuum compression molding, press molding and plug assist molding. However, in any molding method or in a preheating process using an infrared heater or the like, And thereafter a step of molding. Therefore, the molding stress can be lowered at a high temperature, thereby making it possible to mold the resin into a complicated shape. Therefore, it is important to set the stress (F100 value) at 100% elongation at 150 DEG C to 5 MPa or more and 60 MPa or less. If the F100 value is less than 5 MPa, the film can not withstand the tensile force for film transfer in the preheating step in the molding process, and the film may be deformed or broken in some cases, resulting in a film that can not withstand use in molding applications Throw away. On the contrary, if it exceeds 60 MPa, the deformation is insufficient at the time of thermoforming, and molding into a complicated shape becomes difficult. From the viewpoint of handling property and moldability, the stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 占 폚 is preferably 10 MPa or more and 50 MPa or less, and most preferably 15 MPa or more and 45 MPa or less. In addition, when used in a particularly complicated shape, the stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 占 폚 is preferably 5 MPa or more and 36 MPa or less.

In addition, since the biaxially oriented polyester film for molding of the present invention is formed into a more complex shape, it is preferable that the elongation at break at 150 占 폚 in the film longitudinal direction and the transverse direction is 100% or more and 500% or less, respectively. Even in the case of molding into a complicated shape, it is possible to follow a high molding and processing magnification, and also it is possible to obtain excellent economical efficiency and heat resistance. From the viewpoints of moldability, heat resistance, and economy, elongation in the film longitudinal direction and width direction is preferably 100% or more and 400% or less, and most preferably 120% or more and 300% or less. When the film is used for applications requiring dimensional stability, the elongation in the longitudinal direction or the width direction of the film is preferably 120% or more and 200% or less.

In the biaxially oriented polyester film for molding of the present invention, the method of setting the stress and the elongation at break at 100% elongation of the film at 150 DEG C within the above-mentioned range includes, for example, a method in which a structure derived from neopentyl glycol , A structural unit derived from 1,4-cyclohexane dimethanol, a structural unit derived from isophthalic acid, or a structural unit derived from 2,6-naphthalenedicarboxylic acid. Such a structural unit suppresses orientation crystallization of the film at the time of molding, so that the stress (F100 value) at 100% elongation of the film at 150 占 폚 can be suppressed to a low level and the elongation at break can also be improved. As the preferable concentration, the content of the structural unit derived from isophthalic acid and / or the structural unit derived from 2,6-naphthalenedicarboxylic acid with respect to the dicarboxylic acid component in the film is adjusted to 5 mol% or more and 15 mol% or less, Cyclohexane dimethanol and / or structural units derived from neopentyl glycol in an amount of 5 mol% or more and 15 mol% or less.

From the viewpoint of dimensional stability at the time of processing, the biaxially oriented polyester film for molding of the present invention needs to have a storage elastic modulus at 80 DEG C of from 2001 MPa to 4000 MPa. Preferably 2200 MPa to 3500 MPa, and more preferably 2400 MPa to 3000 MPa. If the storage elastic modulus at 80 DEG C is less than 2001 MPa, the dimensional stability in the process of printing, vapor deposition, coating, and lamination is lowered. On the other hand, if the storage elastic modulus is larger than 4000 MPa, the dimensional stability is excellent, but the moldability tends to deteriorate, which is not preferable.

In order to increase the stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 占 폚 in order to improve moldability, each of the structural units derived from neopentyl glycol , A structural unit derived from 1,4-cyclohexane dimethanol, a structural unit derived from isophthalic acid, or a structural unit derived from 2,6-naphthalenedicarboxylic acid is preferably contained. However, The stability is deteriorated. That is, the moldability and the dimensional stability are usually opposite to each other, and it is very difficult to make them compatible. The present invention is characterized in that the stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 占 폚 is 5 to 60 MPa, respectively, and the storage elastic modulus at 80 占 폚 is not less than 2001 MPa and not more than 4000 MPa By weight, thereby achieving both moldability and dimensional stability.

In the biaxially oriented polyester film for molding of the present invention, for example, a method of setting the peak temperature of loss tangent at 100 ° C or higher and 120 ° C or lower is preferably used do. By setting the loss tangent peak temperature within the above range, it becomes possible to control the storage modulus at 80 占 폚 from 2001 MPa to 3500 MPa while maintaining the moldability. The peak of the loss tangent is based on the glass transition of the polymer. If the peak temperature of the loss tangent is less than 100 占 폚, the storage elastic modulus at 80 占 폚 may become less than 2001 MPa and the dimensional stability is lowered. On the other hand, if the peak temperature of the loss tangent is set to be larger than 120 占 폚, the stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 占 폚 may become larger than 60 MPa and the formability is lowered. A more preferable range of the loss tangent is 100 deg. C or more and 115 deg. C or less.

The biaxially oriented polyester film for molding of the invention preferably has a storage elastic modulus in the film longitudinal direction and a transverse direction at 100 DEG C of not less than 1001 MPa and not more than 3000 MPa in order to improve dimensional stability at the time of processing. More preferably 1050 MPa or more and 2500 MPa or less, and most preferably 1100 MPa or more and 2000 MPa or less. By setting the storage elastic modulus in the film longitudinal direction and the transverse direction at 100 占 폚 within the above range, the dimensional stability at the time of processing can be further improved and the processing temperature range is widened, which is highly desirable.

In the biaxially oriented polyester film for molding according to the present invention, the method of setting the storage elastic modulus at 100 deg. C within the above range is not particularly limited. For example, the peak temperature of the loss tangent is set to 105 deg. Method is preferably used, more preferably from 105 캜 to 110 캜.

As a method of controlling the peak temperature of the loss tangent, it is preferable to increase the stretching ratio at a high ratio. The draw ratio is preferably 10 times or more, more preferably 11 times or more, and most preferably 12 times or more. The stretching temperature is preferably lowered to such an extent that uneven stretching does not occur. Particularly, in the case of sequential biaxial stretching in which stretching in the width direction is performed after stretching in the longitudinal direction, a method of lowering the stretching temperature in the longitudinal direction, specifically, a method of setting the temperature at 80 to 90 DEG C is preferable, And a temperature higher than the stretching temperature in the longitudinal direction is preferably 90 占 폚 to 100 占 폚.

It is also preferable to use a constitution comprising a structural unit derived from 2,6-naphthalene dicarboxylic acid having a rigid structure or 1,4-cyclohexanedimethanol having a cyclic structure, and it is preferable that the structure contains a dicarboxylic acid Naphthalene dicarboxylic acid as a component in an amount of 5 mol% or more and 15 mol% or less and a structural unit derived from 1,4-cyclohexane dimethanol as a glycol component in an amount of 5 mol% or more and 15 mol% or less, Or less. On the other hand, a component having many methylene groups which tend to be bent, such as 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 6-hexanediol, succinic acid, adipic acid, sebacic acid, dimeric acid and the like lower the peak temperature of loss tangent, and therefore the content is preferably 5 mol% or less, more preferably 3 mol% or less.

The biaxially oriented polyester film for molding of the present invention is preferably a laminated polyester film having a polyester A layer and a polyester B layer. This is because the layered polyester film having the polyester A layer and the polyester B layer can provide the function of each layer. For example, by providing the dimensional stability by the polyester A layer and imparting the moldability by the polyester B layer, it becomes possible to achieve both dimensional stability and moldability for the purpose of the present invention.

In the case of a laminated polyester film having a polyester A layer and a polyester B layer, it is preferable that the polyester A layer has a plane orientation coefficient of 0.14 or more and 0.17 or less, and the melting point (TmA) of the polyester A layer and the polyester B (TmA-TmB) of the melting point (TmB) of the layer is preferably 7 占 폚 or more and 15 占 폚 or less. The dimensional stability can be ensured by setting the plane orientation coefficient of the polyester A layer to 0.14 or more and 0.17 or less, and the moldability can be attained by making the melting point of the polyester B layer lower than that of the polyester A layer. At this time, the difference (TmA-TmB) between the melting point (TmA) of the polyester A layer and the melting point (TmB) of the polyester B layer was set at 7 deg. C from the viewpoints of moldability, dimensional stability, Or more and 15 占 폚 or less.

From the viewpoints of moldability and dimensional stability, the plane orientation coefficient of the polyester A layer is more preferably 0.145 or more and 0.165 or less, and most preferably 0.149 or more and 0.165 or less.

The polyester A layer preferably has a melting point (TmA) of 250 DEG C or more and 255 DEG C or less and a density of 1.380 g / cm3 or more and 1.400 g / cm3 or less from the viewpoints of heat resistance and dimensional stability. In order to set the melting point and density of the polyester A layer within such a range, it is preferable that the polyester A layer contains 95 mol% or more and less than 99 mol% of a structural unit derived from ethylene glycol or a structural unit derived from 1,4-cyclohexane dimethanol Is contained in an amount of 1 mol% or more and less than 5 mol%. In order to set the melting point and density of the polyester A layer within such a range, it is preferable that the polyester A layer contains 95 mol% or more and less than 99 mol% of the structural unit derived from ethylene glycol and further contains a structural unit derived from 1,4-cyclohexane dimethanol Is contained in an amount of not less than 1 mol% and less than 5 mol%. It is also preferable that the polyester A layer contains a structural unit derived from terephthalic acid in an amount of 95 mol% or more and 100 mol% or less with respect to the structural unit derived from a dicarboxylic acid (including a dicarboxylic acid ester).

The polyester B layer preferably has a melting point (TmB) of 235 DEG C or higher and 245 DEG C or lower and a density of 1.350 g / cm3 or higher and 1.365 g / cm3 or lower from the viewpoint of moldability. In order to set the melting point and the density of the polyester B layer within such a range, the content of the structural unit derived from ethylene glycol is preferably 85 mol% or more and less than 90 mol%, or the structural unit derived from 1,4-cyclohexane dimethanol Is contained in an amount of 10 mol% or more and less than 15 mol%. In order to set the melting point and density of the polyester B layer within such a range, it is preferable that the polyester B layer contains a structural unit derived from ethylene glycol in an amount of 85 mol% or more and less than 90 mol%, and a structural unit derived from 1,4-cyclohexane dimethanol In an amount of 10 mol% or more and less than 15 mol%. It is also preferable that the polyester B layer contains a structural unit derived from terephthalic acid in an amount of 95 mol% or more and 100 mol% or less with respect to the structural unit derived from a dicarboxylic acid (including a dicarboxylic acid ester).

With the above-described constitution, moldability, dimensional stability, and heat resistance are excellent, and the interlayer adhesion between the A layer and the B layer after the high-ratio molding is also excellent.

In the case of a laminated structure, it is preferable that the polyester A layer is located on at least one of the outermost layers from the viewpoint of dimensional stability.

In the case of a laminated structure, the lamination ratio H (-) :( thickness of layer A) / (thickness of the entire film) of layer A is preferably 0.05 or more and 0.4 or less from the viewpoints of moldability and dimensional stability.

The biaxially oriented polyester film for molding of the present invention is required to have a storage elastic modulus in the film longitudinal direction and the transverse direction at 180 DEG C of from 41 MPa to 400 MPa from the viewpoint of heat resistance. If the storage elastic modulus at 180 ° C is less than 41 MPa, the heat resistance is lowered, and the quality of the film surface may be deteriorated, such as roughness of the film surface during molding. On the other hand, if the storage elastic modulus is larger than 400 MPa, moldability may deteriorate, which is not preferable. More preferably 100 MPa or more and 300 MPa or less, and most preferably 130 MPa or more and 250 MPa or less in view of heat resistance and moldability.

As a method for setting the storage elastic modulus in the film longitudinal direction and the width direction at 180 占 폚 to 41 MPa or more and 400 MPa or less, for example, it is preferable to set the melting point of the polyester film to 220 占 폚 or more. From the viewpoint of heat resistance and moldability, the polyester film preferably has a melting point of 230 캜 to 255 캜, and most preferably 235 캜 to 245 캜. Further, in the case of a laminated structure, it is preferable that the melting point (TmA) of the polyester A layer is set to 250 deg. C or higher and 255 deg. The melting point (TmB) of the polyester B layer is preferably 230 占 폚 or higher and 245 占 폚 or lower.

In order to satisfy the moldability, dimensional stability and heat resistance, a laminated polyester film having a polyester A layer and a polyester B layer, wherein the polyester A layer contains a structural unit derived from ethylene glycol in an amount of 95 mol% To 99% by mole, a structural unit derived from 1,4-cyclohexane dimethanol in an amount of not less than 1% by mole and not more than 5% by mole, and a structural unit derived from ethylene glycol in the polyester B- Mol% to less than 90 mol%, and a structural unit derived from 1,4-cyclohexane dimethanol in an amount of 10 mol% or more and less than 15 mol%. Further, it is preferable that the polyester A layer contains a structural unit derived from 1,4-cyclohexane dimethanol in an amount of 1 mol% or more and less than 5 mol%, the structural unit derived from 1,4-cyclohexanedimethanol is 10 Mol% to less than 15 mol%, and the melting point of the film (the melting point of the polyester B layer in the case of the laminated film) is 235 DEG C or more and 245 DEG C or less. In order to set the melting point of the film (the melting point of the polyester B layer in the case of the laminated film) to 235 DEG C or higher and 245 DEG C or lower in such a constitution, a polyethylene terephthalate resin and 1,4-cyclohexanedimethanol copolymerized polyethylene terephthalate A method of mixing the phthalate resin in an extruder is preferably used. At this time, the copolymerization amount of 1,4-cyclohexane dimethanol in the 1,4-cyclohexane dimethanol copolymerized polyethylene terephthalate resin is preferably 25 mol% or more and 35 mol% or less. When the copolymerization amount is used as the resin in the above range, a suitable transesterification reaction proceeds and the melting point of the film (the melting point of the polyester B layer in the case of the laminated film) can be made 235 DEG C or higher and 245 DEG C or lower. The residence time in the extruder of the polyester resin of the polyester B layer is preferably 5 minutes or more and 15 minutes or less.

Here, the melting point of the polyester film is an endothermic peak temperature expressed by a melting phenomenon when measurement is carried out at a heating rate of 20 ° C / min. Using a differential scanning calorimeter (DSC) (to be described later in detail). There is a case where an endothermic peak due to a plurality of fuses appears in a case of using a film made of a mixture of polyester resins having different compositions. In such a case, the endothermic peak temperature, which is the highest temperature, is set to the melting point of the polyester film of the present invention do.

From the standpoint of appearance after molding, the biaxial oriented polyester film for molding of the present invention preferably has a color tone b value of -1.5 to 1.5. When the color tone b value is smaller than -1.5, the appearance of the molded article using the biaxially oriented polyester film for molding of the present invention appears blue and the appearance is damaged. On the other hand, when the hue b value is larger than 1.5, the appearance is yellow and the appearance is degraded. More preferably, the color tone b value is 0 or more and 1.5 or less, and most preferably 0 or more and 1.2 or less. Here, the hue b value is a value obtained by measuring the b value in the Lab colorimetric system according to JIS Z-8722-2000 by transmission measurement. The method of setting the color tone b value to not less than -1.5 but not more than 1.5 is not particularly limited, but it is preferable to control the resin temperature at the time of extrusion in the production of the biaxially oriented polyester film of the present invention to 275 to 290 캜 Do. Since the resin temperature at the time of extrusion may be higher than the temperature of the extruder due to the shearing heat of the resin, it is necessary to set the extruder temperature from the resin kneading time, resin viscosity, and the like. Further, it is preferable to set the inside of the extruder to an inert gas, preferably a flow nitrogen atmosphere, and to set the oxygen concentration in the supply portion to 0.7% by volume or less, more preferably 0.5% by volume or less. The biaxially oriented polyester film for molding according to the present invention is excellent in stress at 100% elongation in the film longitudinal direction and width direction at 150 DEG C, film longitudinal direction at 80 DEG C, The storage elastic modulus and the storage elastic modulus in the film longitudinal direction and the width direction at 180 DEG C are set to be within a specific range. However, as described above, the film composition includes structural units derived from neopentyl glycol, structures derived from 1,4-cyclohexanedimethanol Structural units derived from isophthalic acid and structural units derived from 2,6-naphthalenedicarboxylic acid are preferably contained. However, since the extrusion heat resistance may be lowered by containing these components, the resin temperature at the time of extrusion, oxygen Concentration becomes important. Further, by employing the above-mentioned extrusion temperature and oxygen concentration, the color tone b value can be set to be -1.5 or more and 1.5 or less. In order to control the moldability, dimensional stability and color tone, it is also effective to set the heat treatment temperature after biaxially stretching to a specific range in the production process of the biaxially oriented polyester film for molding of the present invention. From the viewpoints of moldability and dimensional stability, it is effective to set the heat treatment temperature at a high temperature and a long time. However, when the heat treatment temperature is set at a high temperature and a long time, the color tone b value may deviate from the range of -1.5 to 1.5. For this reason, a multi-step heat treatment method in which heat treatment is performed again at a high temperature and a short time after the heat treatment and then at a low temperature is preferable. In this case, the preferable high-temperature heat treatment temperature is 200 ° C to 240 ° C, and more preferably 215 ° C to 230 ° C. The high-temperature heat treatment time is preferably 10 seconds to 40 seconds, more preferably 15 seconds to 30 seconds. The low temperature heat treatment temperature after the high temperature heat treatment is preferably 120 to 180 占 폚, and the low temperature heat treatment temperature is preferably 5 to 15 seconds. Also, a method of performing annealing at off-line after producing a film by performing a heat treatment at a high temperature and a short time is also very effective.

In order to improve the dimensional stability after molding, the biaxially oriented polyester film for molding of the present invention preferably has a heat shrinkage ratio in the longitudinal direction and the transverse direction at 150 ° C of 1% or less. In order to improve the dimensional stability after molding, the heat shrinkage ratio in the longitudinal direction and the width direction at 150 캜 is preferably -1% or more. Here, the heat shrinkage ratio in the longitudinal direction and the width direction at 150 DEG C means that the film is cut into a rectangle having a length of 150 mm and a width of 10 mm in the longitudinal direction and the width direction, and a line is drawn at intervals of 100 mm on the sample. Quot; indicates the rate of change of the distance between the lines before and after the heat treatment was performed for 30 minutes in a hot air oven heated to 150 캜.

The heat shrinkage rate at 150 ° C in both the longitudinal direction and the width direction is preferably -1% or more, and more preferably 1% or less, whereby it is possible to suppress deformation when the formed member is heated.

Examples of the method of setting the heat shrinkage ratio in the longitudinal direction and the transverse direction at 150 ° C in both the range of -1% to 1% are, for example, a method of adjusting the heat treatment conditions of the film after biaxially stretching. From the viewpoints of dimensional stability and film quality, the heat treatment temperature after biaxially stretching is preferably 200 to 240 占 폚, and preferably 210 to 235 占 폚 And most preferably from 215 ° C to 230 ° C. In addition, the heat treatment temperature of the biaxially oriented polyester film for molding of the present invention is determined by a DSC curve measured at a heating rate of 20 ° C / min in a nitrogen atmosphere in a differential scanning calorimeter (DSC) Can be obtained from the endothermic peak.

The preferable heat treatment time is 5 to 60 seconds, but it is preferably 10 to 40 seconds, more preferably 15 to 30 seconds from the viewpoints of moldability, dimensional stability, color tone and productivity. In addition, the heat treatment is preferably carried out while relaxing in the longitudinal direction and / or the width direction because the heat shrinkage rate can be reduced. The relaxation rate (relaxation rate) at the time of heat treatment is preferably 3% or more, more preferably 3% or more and 10% or less, and most preferably 3% or more and 5% or less from the viewpoints of dimensional stability and productivity.

Also, a method of performing heat treatment under two or more stages is also highly desirable. It is possible to further reduce the heat shrinkage rate by heat-treating at a temperature lower than the heat-treatment temperature after loosening in the longitudinal direction and / or the width direction after the heat-treatment at a high temperature of 200 ° C to 245 ° C. The second heat treatment temperature at this time is preferably 120 ° C to 180 ° C, more preferably 150 ° C to 180 ° C.

As a method for further reducing the heat shrinkage rate, there is an off-annealing treatment. That is, the heat treatment is performed again on the polyester film once wound.

The heat shrinkage rate at 150 캜 is more preferably 0.8% or less, and most preferably 0.5% or less.

The biaxially oriented polyester film for molding according to the present invention has a load of 19.6 mN in order to improve the dimensional stability after molding, and a film at 150 DEG C in at least one direction when the temperature is raised from 25 DEG C to 220 DEG C at a temperature raising rate of 5 DEG C / Is preferably 0 to + 3%. By satisfying the above characteristics, it is possible to suppress the deformation of the film when it is stored under heating conditions after the film formation, and it is possible to prevent occurrence of problems such as insert molding, warping of the in-mold molded article, and peeling of the film from the resin (Dimensional stability after molding can be evaluated, for example, in [Dimensional stability 1 after molding (Example 21)).

In order to improve the dimensional stability after molding, the off-annealing process is very effective as described above. However, the off-annealing process is performed at a temperature of 140 ° C or more and less than 160 ° C, It is possible to set the thermal strain in the width direction within the above range and further reduce the winding speed in the longitudinal direction by + 0.5 to 5% from the winding speed, . Further, it is preferable to form a stepwise cooling zone after the off-annealing treatment since the heat shrinkage rate can be further reduced. More preferably, the film has a load of 19.6 mN. When the temperature is raised from 25 ° C to 220 ° C at a rate of 5 ° C / min, the film has a thermal strain of 0 to + 3% at 150 ° C in the longitudinal and transverse directions, And the thermal strain of the film at 150 DEG C in the width direction is +0.5 to + 2%.

The biaxially oriented polyester film for molding according to the present invention has a load of 19.6 mN when the dimensional stability after molding is developed to a particularly strict application and is at least 19.6 mN when the temperature is raised from 25 캜 to 220 캜 at a temperature raising rate of 5 캜 / It is preferable that the thermal strain of the film at 180 DEG C in one direction is 0 to + 3%. More preferably, the film has a load of 19.6 mN. When the temperature is raised from 25 ° C to 220 ° C at a rate of 5 ° C / min, the film has a thermal strain of 0 to + 3% at 150 ° C in the longitudinal and transverse directions, And the thermal strain of the film at 180 DEG C in the width direction is +0.5 to + 2%. By satisfying the above characteristics, it is possible to suppress the deformation of the film when the film is stored under high temperature heating conditions after the film formation, and it is possible to prevent occurrence of problems such as insert molding, warpage of the in- (Dimensional stability after molding can be evaluated, for example, in [Dimensional stability 2 after molding (Example 22)).

In order to achieve the above-described thermal strain, the thermal annealing treatment temperature is set to 160 ° C or more and 180 ° C or less, and the width direction is free, that is, the film is not constrained in the film width direction, , And the thermal strain in the longitudinal direction can be set within the above range by reducing the winding speed in the longitudinal direction by 0.5 to 5% from the winding speed. Further, it is preferable to form a stepwise cooling zone after the off-annealing treatment since the heat shrinkage rate can be further reduced. More preferably, the film has a load of 19.6 mN and the film has a thermal strain of 0 to + 3% at 180 ° C in the longitudinal direction and the width direction when the temperature is raised from 25 ° C to 220 ° C at a heating rate of 5 ° C / And the thermal strain of the film at 180 DEG C in the width direction is +0.5 to + 2%.

The biaxially oriented polyester film for molding of the present invention preferably has a birefringence (? N) of less than 20 占^10-3 from the viewpoint of uniform moldability. Here, the uniform formability means that the anisotropy of the film is small and the difference in the degree of molding is small depending on the direction. Further, the birefringence is a value defined by the refractive index of the film as measured by an Abbe refractometer or the like, assuming that the refractive index in the longitudinal direction of the film and the refractive index of n _MD, in the transverse direction _{n TD, Δn = | n MD} -n TD | . When the birefringence is 20 x 10 < ^-3 > or more, it is not preferable because the orientation balance in the plane direction of the film is poor and the formability may be deteriorated due to the influence of the direction of high orientation. If in order to enhance a more uniform formability it is less than less than 15 × 10 ^-3 and more preferably, 10 × 10 ^-3 is most preferred. In order to set the birefringence in the above range, for example, it can be achieved by adjusting the draw ratio. In the case of the biaxial stretching method, the birefringence can be reduced by bringing the draw ratio in the longitudinal direction and the width direction close to each other. For example, the stretching magnification in the longitudinal direction is 3 to 3.8 times, the stretching magnification in the width direction is 3 to 3.8 times, preferably the stretching magnification in the longitudinal direction is 3 to 3.5 times, the stretching magnification in the width direction is 3 to 3.5 It is preferable to double. In order to keep the birefringence within the above-mentioned range, the preheating temperature of the transverse stretching is preferably 80 to 100 占 폚, more preferably 85 to 95 占 폚. The transverse stretching temperature is preferably 90 占 폚 to 120 占 폚, more preferably 95 占 폚 to 110 占 폚, and most preferably 90 占 폚 to 100 占 폚.

It is preferable that the biaxially oriented polyester film for molding of the present invention has a haze of less than 0.01% / 탆 from the standpoint of designability of a molded member after molding. When the haze is less than 0.01% / mu m, it is preferable to improve the designability of the molded member.

As a method of setting the haze to 0.01% / mu m or less, there is a method of reducing the concentration of the contained particles as much as possible in order to improve the transportability of the film. The biaxially oriented polyester film for molding of the present invention may contain particles in the film in order to improve the transportability of the film. Here, the particles to be used are not particularly limited, but externally added particles are preferably used in terms of transportability and appearance. Examples of the externally added particles include wet and dry silica, colloidal silica, aluminum silicate, titanium oxide, calcium carbonate, calcium phosphate, barium sulfate and aluminum oxide. Examples of the organic particles include styrene, silicone, acrylic acid, Polyesters, divinyl compounds and the like can be used. Among them, it is preferable to use inorganic particles such as wet and dry silica and alumina, and particles composed of styrene, silicone, acrylic acid, methacrylic acid, polyester, divinylbenzene and the like. These externally added particles may be used in combination of two or more kinds. The content of the particles in the film is preferably from 0.001 to 0.02 mass%, more preferably from 0.002 to 0.01 mass%, based on 100 mass% of the entire film from the viewpoint of transportability and appearance.

As a method for reducing the particle concentration without lowering the transportability of the film, for example, a method of forming a laminated film of two or more layers having at least an A layer and a B layer, and adding particles only to the A layer or the B layer . By adding the particles only to the layer A or the layer B, the amount of added particles can be reduced, and the haze can be reduced without deteriorating the handling property. In order to further improve the handling property, it is highly preferable that a three-layer structure of layer A / layer B / layer C is used, and that only particles A and C are contained.

It is preferable that the lamination ratio H (-) (H (-) = (thickness of layer A) (mu m) / (thickness of entire film) (mu m)) of layer A is 0.01 or more and 0.4 or less. If the lamination ratio is less than 0.01, the thickness of the A layer becomes too thin to cause lamination unevenness, which is not preferable. When the lamination ratio is larger than 0.4, the content of the particles increases and the haze may increase. The lamination ratio H (-) is preferably from 0.02 to 0.3, more preferably from 0.03 to 0.25. Also, in the case of a three-layer structure of A / B / C, it is preferable that {(thickness of A layer + thickness of C layer) / (thickness of entire film) is 0.01 or more and 0.4 or less. From the viewpoint of the film formability, it is preferable that the lamination thicknesses of the A layer and the C layer are equal. The lamination thickness ratio can be achieved by adjusting the discharge amount when the polyester A constituting the A layer and the polyester B constituting the B layer are extruded. The amount of discharge can be appropriately adjusted according to the number of revolutions of the extruder screw, the number of revolutions of the gear pump when the gear pump is used, the extrusion temperature, and the viscosity of the polyester raw material. The lamination ratio of the film can be obtained by observing the cross section of the film by a scanning electron microscope, a transmission electron microscope, an optical microscope or the like at a magnification of 500 times or more and 10000 times or less to measure the thickness of each lamination layer.

The film thickness of the biaxially oriented polyester film for molding of the present invention is preferably 25 占 퐉 or more and 500 占 퐉 or less, more preferably 50 占 퐉 to 300 占 퐉, and more preferably 75 占 퐉 or more And most preferably 250 탆 or less.

Next, an example of a specific production method of the biaxially oriented polyester film for molding of the present invention will be described, but the present invention is not limited to these examples.

In the case of a laminated polyester film having a polyester A layer and a polyester B layer, first, as a polyester A used in the polyester A layer, a polyethylene terephthalate resin (a) and 1,4- The terephthalate resin (b) is weighed at a predetermined ratio. Further, the polyester terephthalate resin (c) and the 1,4-cyclohexane dimethanol copolymerized polyethylene terephthalate resin (d) as the polyester B to be used for the polyester B layer are metered at a predetermined ratio.

Then, the mixed polyester resin is supplied to a vent type twin-screw extruder and melt-extruded. At this time, it is preferable to control the oxygen concentration in the extruder to 0.7% by volume or less and the resin temperature to 275 to 295 ° C in an atmosphere of flowing nitrogen. Thereafter, foreign matters are removed through the filter and the gear pump, and the amount of extrusion is homogenized, and discharged from the T die onto the cooling drum in a sheet form. At that time, an electrostatic application method in which a cooling drum and a resin are adhered to each other with an electrostatic force using an electrode with a high voltage, a casting method in which a water film is formed between the casting drum and the extruded polymer sheet, a casting drum temperature, (Glass transition point -20 占 폚), or by a method in which a plurality of these methods are combined, the sheet-like polymer is brought into close contact with the casting drum and cooled and solidified to obtain an unstretched film. Among these casting methods, when polyester is used, a method of applying an electric charge in view of productivity and planarity is preferably used.

The film of the present invention needs to be a biaxially oriented film from the viewpoints of heat resistance and dimensional stability. The biaxial oriented film can be obtained by a sequential biaxial stretching method in which an unstretched film is stretched in the longitudinal direction, stretched in the width direction or stretched in the width direction and then stretched in the longitudinal direction, And simultaneously stretching by a simultaneous biaxial stretching method in which stretching is performed at substantially the same time.

The stretching magnification in this stretching method is preferably 3.0 times or more and 4.2 times or more, more preferably 3.0 times or more and 4.0 times or less, and particularly preferably 3.0 times or more and 3.8 times or less, in each of the longitudinal direction and the width direction Is adopted. The stretching speed is preferably 1,000% / min to 200,000% / min or less. The stretching temperature is preferably 70 占 폚 or more and 120 占 폚 or less in the longitudinal direction and 80 占 폚 or more and 120 占 폚 or less in the transverse direction. The stretching may be performed a plurality of times in each direction.

After biaxial stretching, the film is heat-treated. The heat treatment can be performed by any conventionally known method such as heating in an oven or the like. The heat treatment is carried out at a temperature of not lower than 120 캜 and not higher than the melting point of the polyester, but is preferably 200 캜 to 240 캜, more preferably 210 캜 to 235 캜, and most preferably 215 캜 to 230 캜 Do. The heat treatment time may be arbitrarily set within a range that does not deteriorate the characteristic, and is preferably 5 seconds or more and 60 seconds or less, more preferably 10 seconds or more and 40 seconds or less, and most preferably 15 seconds or more and 30 seconds or less It is good to do. The heat treatment may be performed by loosening the film in the longitudinal direction and / or the width direction. At least one side may be corona treated or the adhesive layer may be coated in order to improve the adhesive strength between the printing layer, the adhesive layer, the hard coat layer, and the inner layer. As a method of installing the coating layer in an in-line manner in a film production process, a method in which a coating layer composition is dispersed in water on a monoaxially stretched film is uniformly coated using a metal ring ring bar or a gravure roll, It is preferable that the thickness of the adhesive layer is 0.01 m or more and 1 m or less. Further, various additives such as an antioxidant, a heat stabilizer, an ultraviolet absorber, an infrared absorber, a pigment, a dye, an organic or inorganic particle, an antistatic agent and a nucleating agent may be added to this adhesive layer. The resin preferably used for the adhesive layer is preferably at least one resin selected from an acrylic resin, a polyester resin and a urethane resin from the viewpoints of adhesiveness and handleability. Among them, an acrylic resin is preferable because it is excellent in weather resistance, heat resistance and moisture resistance. In order to improve dimensional stability after molding, it is preferable to perform the off-annealing at 140 to 180 캜.

The biaxially oriented polyester film for molding of the present invention preferably contains an antioxidant in view of the quality of the film. By containing the antioxidant, it is possible to suppress the oxidative decomposition in the drying step and the extrusion step of the polyester resin, and it is possible to prevent deterioration of quality due to the gel-like foreign matter. The kind of the antioxidant is not particularly limited, and for example, antioxidants classified into hindered phenols, hydrazines, phosphites and the like can be preferably used. Among them, pentaerythrityl tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,5-di-t-butyl- (3, 5-di-t-butyl-4-hydroxybenzyl) benzene, tris -Butylphenyl) phosphite and the like are preferably used.

The biaxially oriented polyester film of the present invention can impart weather resistance when used outdoors. As a method of imparting weather resistance, there is a method of laminating an inner layer. The inner layer absorbs light energy of at least 350 nm and not more than 360 nm and emits harmless thermal energy, phosphorescence or fluorescence by very fast energy conversion, and suppresses photoexcitation and photochemical reaction of the impurities in the polymer to cause whitening, embrittlement, For example, a weather-resistant resin layer, a layer containing an ultraviolet absorber in various resin layers, and the like. In particular, it is preferable that the average transmittance in the wavelength range of 350 nm or more and 360 nm or less after lamination is 45% or less, preferably 30% or less, more preferably 10% or less. The preferable range of the thickness of the inner layer is 0.5 mu m or more and 20 mu m or less, more preferably 1 mu m or more and 15 mu m or less, and most preferably 2 mu m or more and 10 mu m or less. Further, a method of adding an anti-seizure agent may be mentioned. In the case of adding an inner coating agent, it is preferable that the average transmittance of the film in the wavelength range of 350 nm to 360 nm is 45% or less, preferably 30% or less, more preferably 10% or less . The endurance agent to be used is not particularly limited, and examples thereof include benzophenone-based compounds, triazine-based compounds, benzotriazole based compounds, salicylic acid based compounds, salicylate based compounds, cyanoacrylate based compounds, nickel based compounds, benzooxazinone based compounds , Cyclic imino ester compounds, and the like can be preferably used. Among them, a benzotriazole-based compound, a benzophenone-based compound, and a benzoxazinone-based compound are preferably used, and a benzoxazinone-based compound is particularly preferably used from the viewpoint of dispersibility. These compounds may be used singly or in combination of two or more. In addition, a stabilizer such as HALS (Hinderd Amine Light Stabilizer) and an antioxidant may be used in combination, and in particular, an antioxidant of phosphorus is preferably used in combination. Examples of the benzotriazole-based compound include 2-2H-benzotriazol-2-yl) -4,6-bis (1-methyl- 2- (2H-benzotriazol-2-yl) -4-methylphenol, 2- -Yl) -4,6-di-t-butylphenol, 2- (2H-benzotriazol-2-yl) Butylphenol, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5- chlorobenzotriazole, 2- ', 5'-di-t-butylphenyl) -5-chlorobenzotriazole, and the like. Examples of the benzophenone-based compound include 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone , 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid and the like. Examples of the benzooxazinone compound include 2-p-nitrophenyl-3,1-benzoxazine-4-one, 2- (p-benzoylphenyl) - (2-naphthyl) -3,1-benzoxazine-4-one, 2,2'- 2,6-naphthylene) bis (3,1-benzoxazine-4-one), and the like. In addition, it is preferable to use the cyanoacrylate-based tetrameric compound in combination with another ultraviolet absorber in view of imparting excellent weather resistance. In this case, the content of the cyanoacrylate based tetrameric compound is preferably 0.05 to 2% by weight, more preferably 0.1 to 1.0% by weight. The cyanoacrylate based tetrameric compound is a compound based on a tetravalent cyanoacrylate, and examples thereof include 1,3-bis (2 'cyano-3,3-diphenylacryloyloxy) -2 , 2-bis- (2 'cyano-3,3-diphenylacryloyloxymethylpropane). As ultraviolet absorbers to be used in combination with cyanoacrylates, benzooxazinone compounds, particularly 2,2 '- (1,4-phenylene) bis (4H-3,1-benzoxazin-4-one) , And the addition amount thereof is preferably 0.3 to 1.5% by weight in the film.

The biaxially oriented polyester film for molding of the present invention can be laminated with a hard coat layer when it is used in particularly severe applications. The hard coat layer is not particularly limited as long as it is high in hardness, excellent in resistance to wear and abrasion, and can be composed of acrylic, urethane, melamine, organosilicate compound, silicone, metal oxide and the like. Particularly, it is preferably used in view of hardness and durability, curability and productivity, and is preferably composed of an acrylic type, particularly an active ray-curable acrylic type composition or a thermosetting type acrylic type composition. In the present invention, the pencil hardness of the film after lamination of the hard coat layer is preferably not less than HB, more preferably not less than H, and most preferably not less than 2H.

When the biaxially oriented polyester film for molding according to the present invention is used for metal plating, it is preferable to use a metal compound deposited on at least one side of the film. By using a metal compound, it is possible to use it as a substitute for a molded part in which the plated resin is used. Among them, it is more preferable to use a metal compound having a melting point of 150 ° C or more and 400 ° C or less. By using a metal having such a melting range, the metal layer deposited in the moldable temperature region of the polyester film can be formed and processed, and the occurrence of defects in the deposition layer due to the molding can be suppressed easily, which is preferable. A particularly preferable melting point of the metal compound is from 150 캜 to 300 캜. The metal compound having a melting point of not lower than 150 ° C but not higher than 400 ° C is not particularly limited, but indium (157 ° C) or tin (232 ° C) is preferable and indium can be preferably used particularly in terms of metallic luster and color tone. As a method for producing the vapor deposition film, a vacuum deposition method, an EB deposition method, a sputtering method, an ion plating method, or the like can be used. Further, in order to further improve the adhesion between the polyester film and the vapor deposition layer, the surface of the film may be pretreated by a method such as corona discharge treatment or coating with an anchor coating agent in advance. The thickness of the vapor deposition film is preferably from 1 nm to 500 nm, more preferably from 3 nm to 300 nm. In terms of productivity, it is preferable that the thickness is 3 nm or more and 200 nm or less.

In addition, when the biaxially oriented polyester film for molding of the present invention is used on the surface of a molded member by performing printing, appearance and designability can be imparted. The printing method is not particularly limited, but gravure printing, offset printing, screen printing and the like are preferably used. The thickness of the print layer is preferably 1 nm or more and 20 占 퐉 or less.

The biaxially oriented polyester film for molding of the present invention is preferably used for decorative use of a molded member, but is preferably used as a molding decoration method, for example, for an in-mold molding application and an insert molding application. The in-mold molding referred to herein is a molding method in which a film itself is provided in a mold and molded into a desired shape with a resin pressure to be injected to obtain a molding edged body. Insert molding is a molding method in which a film molding object to be provided in a mold is prepared by vacuum molding, pressure molding, vacuum compression molding, press molding, plug assist molding or the like, and filling the resin in such a shape to obtain a molding decorating body. The biaxially oriented polyester film for molding of the present invention is particularly preferably used for insert molding in that it can produce a more complicated shape.

The biaxially oriented polyester film for molding of the present invention is molded by various molding methods such as vacuum molding, pressure molding, vacuum compression molding, and injection molding with in-mold molding because molding stress in the molding temperature range is low. In addition, since the storage elastic modulus in the processing temperature range is within a specific range, edibility can be performed by printing, vapor deposition or the like because of excellent dimensional stability in processing steps such as coating, laminating, printing and vapor deposition, It is excellent in heat resistance because it has a high storage elasticity in a region and exhibits excellent surface properties even after molding and has excellent color tone so that it has a good appearance and can be used for a wide variety of applications such as building materials, And can be suitably used for decorating molded parts such as parts.

Example

(1) melting point, glass transition temperature

Measurement and analysis were carried out in accordance with JIS K7121-1987 and JIS K7122-1987 using a differential scanning calorimeter (Seiko Denshi Co., Ltd., RDC220). 5 mg of the polyester film was used as a sample and the temperature at the apex of the endothermic peak obtained from the DSC curve when the temperature was elevated from 25 占 폚 to 300 占 폚 at 20 占 폚 / When a plurality of endothermic peaks are present, the temperature at the apex of the endothermic peak on the highest temperature side is defined as the melting point. In addition, the specific heat change based on the transition from the glass state to the rubber state is read, and a straight line extending equidistantly from the straight line extending from each base line in the direction of the vertical axis (the axis representing the heat flow) The midpoint glass transition temperature of this intersection point was determined to be the glass transition temperature.

(2) intrinsic viscosity of polyester

The intrinsic viscosity of the polyester resin and the film was measured by dissolving the polyester in orthochlorophenol and using an Oswald viscometer at 25 ° C.

(3) Composition of polyester

The polyester resin and the film are dissolved in hexafluoroisopropanol (HFIP), and the content can be quantified with respect to each monomer residue component and by-product diethylene glycol using ¹ H-NMR and ¹³ C-NMR. In the case of a laminated film, components constituting each layer can be collected and evaluated by removing each layer of the film according to the lamination thickness. For the film of the present invention, the composition was calculated from the mixing ratio at the time of film production.

(4) Content of particles contained in the film

10 g of the polyester film is dissolved in 100 g of orthochlorophenol, and the particles are centrifuged from the polyester to evaluate whether or not the particles are contained in the film. Further, the particle concentration is obtained from the following.

(Particle concentration) = (mass of particles) / (mass of film as a whole) x 100

The film of the present invention was calculated from the particle concentration in the particle master produced by adding particles at the time of polymerization and the particle master concentration in the film.

(5) Hayes

The film haze was measured using a haze meter (HGM-2GP manufactured by Suga Shikenki Co., Ltd.) according to JIS K 7105 (1985). The measurement was performed at three arbitrary positions, and the average value was adopted. The haze in the present invention represents the haze value with respect to the film thickness.

(6) Film thickness, layer thickness

The film was embedded in an epoxy resin, and the cross section of the film was cut into a microtome. The cross section was observed with a transmission electron microscope (TEM H7100, manufactured by Hitachi, Ltd.) at a magnification of 5000 times to determine the film thickness and the thickness of the polyester layer.

(7) plane orientation coefficient, birefringence

(N _MD ), the refractive index (n _TD ) in the width direction and the refractive index (n _ZD ) in the thickness direction of the film were measured using an Abbe's refractometer using a sodium D line (wavelength: 589 nm) Plane orientation coefficient fn and birefringence (n) were calculated.

fn = (n _MD + n _TD ) / 2-n _ZD

? N = | n _MD -n _TD |.

(8) Stress at 100% elongation at 150 DEG C (F100 value)

The film was cut into a rectangle having a length of 150 mm and a width of 10 mm in the longitudinal direction and the width direction, and a sample was obtained. A tensile test was conducted in the longitudinal direction and the transverse direction of the film by using a tensile tester (Orientech Tensilon UCT-100) with an initial tensile chuck distance of 50 mm and a tensile speed of 300 mm / min. The film sample was set in a constant temperature layer set at 150 占 폚 in advance, and a tensile test was performed after preheating for 90 seconds. The load applied to the film when the sample was stretched 100% (when the distance between the chucks was 100 mm) was read and the value obtained by dividing the cross sectional area of the sample before the test (film thickness x 10 mm) by 100% . The measurement was performed five times in each direction of each sample, and the evaluation was made by the average value.

(9) Breaking elongation at 150 ° C

The tensile test was performed in the longitudinal direction and the transverse direction of the film in the same manner as in (8), and the elongation at break of the film was taken as the elongation. The measurement was performed five times in each direction of each sample, and the evaluation was made by the average value.

(10) Storage point elastic modulus, loss tangent

The film was cut into a rectangle having a length of 60 mm and a width of 5 mm in the longitudinal direction and the width direction, and a sample was obtained. The storage elastic modulus (E ') at 80 deg. C, 100 deg. C and 180 deg. C and the peak temperature of loss tangent were obtained under the following conditions using a dynamic viscoelasticity measuring apparatus (DMS6100, manufactured by Seiko Instruments Inc.).

Frequency: 10 Hz, sample length: 20 mm, minimum load: about 100 mN, amplitude: 10 m,

Measuring temperature range: -50 ° C to 200 ° C, heating rate: 5 ° C / min.

(11) Heat shrinkage

The film was cut into a rectangle having a length of 150 mm and a width of 10 mm in the longitudinal direction and the width direction, respectively. A sample was placed at intervals of 100 mm, and 3 g of the weight was suspended and placed in a hot air oven heated at 150 캜 for 30 minutes to conduct heat treatment. The distance between the lines after the heat treatment was measured, and the heat shrinkage ratio was calculated from the change in the distance between the lines before and after the heating by the following formula. The measurement was carried out by taking five samples in the longitudinal direction and the width direction of each film and evaluating the average value.

Heat shrinkage percentage (%) = {(distance between marks before heat treatment) - (distance between markings after heat treatment)} / (distance between markings before heat treatment) 占 100.

(12) Thermal strain

The film was cut into a rectangle having a length of 50 mm and a width of 4 mm in the longitudinal direction and the width direction, and the film length at each temperature was measured using a thermomechanical analyzer (TMA EXSTAR6000, manufactured by Seiko Instruments Inc.) Was regarded as a thermal strain rate.

Sample length: 15 mm, load: 19.6 mN, temperature raising rate: 5 DEG C / min,

Measuring temperature range: 25 ~ 220 ℃

Thermal strain (%)

= [{Film length (mm) at the target temperature - Sample length (mm)} / Sample length (mm)] × 100.

(13) Density

A density spherical tube made of an aqueous solution of sodium bromide maintained at 25 DEG C was used, the film was impregnated at 25 DEG C for 12 hours, and the density was measured by the position reached. In addition, 3 samples were impregnated at each level, and the average value was adopted.

(14) b value

The b value of each film was measured using a spectroscopic colorimeter (SE-2000 manufactured by Nippon Denshiki Co., Ltd., 12V 4A light source halogen lamp, 0 ° ~ -45 ° post spectrometer) according to JIS Z 8722 Was measured by the method.

(15) Moldability

The polyester film of the present invention was heated to a temperature of 150 캜 using a far infrared ray heater at 450 캜 and then subjected to vacuum and pressure molding (compression molding) along a square mold (70 x 70 mm, height 25 mm) heated to 60 캜 : 0.2Ma). For each of the square molds, three types of R of 1 mm, 2 mm and 3 mm were prepared for each edge portion, and vacuum and pressure molding were performed. The state in which molding was performed along the mold was evaluated based on the following criteria.

S: R 1 mm (R 1 mm could be reproduced).

A: It was possible to mold with R 2 mm (R 2 mm could be reproduced), but molding with R 1 mm was not possible.

B: R 3 mm was formed (R 3 mm was reproduced), but R 2 mm could not be molded.

C: R 3 mm.

(16) Uniform Moldability

(8), the difference between the absolute values of the F100 values in the film length direction and the width direction was evaluated as follows.

S: Difference between absolute value of F100 value in film length direction and width direction is less than 10

A: Difference between absolute value of F100 value in film length direction and width direction is 10 or more and less than 15

B: Difference between absolute values of F100 values in the film longitudinal direction and width direction is 15 or more and less than 20

C: Difference between the absolute value of the F100 value in the film longitudinal direction and the width direction is 20 or more.

(17) Film appearance

Screen printing was performed on the surface of the film. The printing was performed under the conditions of a squeegee speed of 300 mm / sec and a squeegee angle of 45 degrees using the ink U-PET (517) and screen SX270T manufactured by MINO GROUP CO., LTD., Followed by drying in a hot air oven under 70 ° C for 15 minutes , And a print layer laminated film was obtained. For the obtained print layer laminated film, the appearance of the film from the opposite side of the print layer was evaluated according to the following criteria.

S: The print was clear and the appearance was excellent in design.

A: The print was a little bit fanciful, but the appearance was excellent in design.

B: The print was a haze, but the design was a problem-free level.

C: The print was unclear and the appearance was poor.

(18) Dimensional stability 1

The film surface on the opposite surface of the print layer to the print layer laminated film subjected to screen printing and drying under the same conditions as in (17) was evaluated according to the following criteria.

S: No roughness or wrinkles were observed on the surface of the film, and the surface was excellent.

A: Some wrinkles were seen on the surface of the film, but the surface was excellent.

B: Wrinkles were seen on the surface of the film, but the surface had no problem.

C: Moisture was generated on the surface of the film, and the surface property was poor.

(19) Dimensional stability 2

Screen printing was carried out under the same conditions as in (17), and the film surface on the opposite side of the printing layer to the printing layer laminated film dried in a hot air oven under the condition of 80 캜 for 15 minutes was evaluated according to the following criteria.

S: No surface roughness or wrinkles were seen on the surface of the film, and the surface was excellent.

A: Some wrinkles were seen on the surface of the film, but the surface was excellent.

B: Wrinkles were seen on the surface of the film, but the surface had no problem.

C: Moisture was generated on the surface of the film, and the surface property was poor.

(20) Heat resistance

The surface of the molded body molded in the mold 15 was evaluated according to the following criteria.

S: No roughness or wrinkles were seen on the surface of the molded article, and the surface was excellent.

A: Some wrinkles were observed on the surface of the molded article, but the surface was excellent.

B: Wrinkles were seen on the surface of the molded article, but the surface properties were at a problem level.

C: Moisture was generated on the surface of the molded article, and the surface property was poor.

(21) Dimensional stability after molding 1

The molded article molded by the injection molding machine 15 was set in an injection molding die and injection molding was performed by injection molding a PC / ABS resin (SD Polycar IM6011) manufactured by Sumitomo DOW Co., Ltd., at a molding temperature of 260 占 폚. The obtained molded article was subjected to a heat resistance test at 70 占 폚 for 10 hours, and evaluation was conducted based on the following criteria.

A: No change was observed in the shape of the molded article.

B: The molded article was warped to the film side, but the level was practically unproblematic.

C: The formed article was bent toward the film side, and the film was peeled from the end of the formed article.

(22) Dimensional stability after molding 2

The molded article molded by the injection molding machine 15 was set in an injection molding die and injection molding was performed by injection molding a PC / ABS resin (SD Polycar IM6011) manufactured by Sumitomo DOW Co., Ltd., at a molding temperature of 260 占 폚. The obtained molded article was subjected to a heat resistance test at 80 DEG C for 10 hours, and evaluation was conducted based on the following criteria.

A: No change was observed in the shape of the molded article.

B: The molded article was warped to the film side, but the level was practically unproblematic.

C: The formed article was bent toward the film side, and the film was peeled from the end of the formed article.

(23) Weathering test

Ultraviolet ray deterioration accelerating tester Using the ISU Super UB tester SUV-W131 (manufactured by Iwasaki DENKI KK), a forced ultraviolet irradiation test was carried out under the following conditions.

Illuminance: 100 mW / cm 2, temperature: 60 캜, relative humidity: 50% RH, irradiation time: 6 hours

The b value of the film before and after the light resistance test was measured by a transmission method according to JIS K-7105 using a spectroscopic colorimeter SE-2000 type (manufactured by Nippon Denshiki Co., Ltd.) And the evaluation was performed based on the standards.

A: Δb value less than 4

B:? B value is 4 or more

(24) Interlayer adhesion

(8), a tensile test was carried out five times in the longitudinal direction and the transverse direction of the film, respectively. On both sides of the rupture portion when the film was broken, OPP adhesive tape (Monofron Ace No. 375, manufactured by Nitto Denko Co., ), The structure of the film sample / OPP adhesive tape after the OPP adhesive tape / tensile test was made, and the film sample after the tensile test was forcibly 180 ° peeled off from the single fluorine tape, and evaluated by the following criteria .

A: No delamination occurred at all.

B: Peeling occurred more than once among the A layer / B layer.

(Production of polyester)

The polyester resin provided in the film formation was prepared as follows.

(Polyester A)

A polyethylene terephthalate resin (intrinsic viscosity: 0.65) having 100 mole% of a terephthalic component as a dicarboxylic acid component, 98.8 mole% of an ethylene glycol component as a glycol component, and 1.2 mole% of a diethylene glycol component.

(Polyester B)

Copolymer polyester (GN001 manufactured by Eastman Chemical Company) in which 1,4-cyclohexane dimethanol was copolymerized in an amount of 33 mol% based on the glycol component was used as cyclohexane dimethanol copolymerized polyethylene terephthalate (intrinsic viscosity: 0.75).

(Polyester C)

A neopentyl glycol copolymerized polyethylene terephthalate resin having a terephthalate component of 100 mol% as a dicarboxylic acid component, 68.5 mol% of an ethylene glycol component as a glycol component, 30 mol% of a neopentyl glycol component and 1.5 mol% of a diethylene glycol component (Intrinsic viscosity 0.75).

(Polyester D)

An isophthalic acid copolymerized polyethylene terephthalate resin having 82.5% by mole of terephthalic acid component, 17.5% by mole of isophthalic acid component, 98.5% by mole of ethylene glycol component as glycol component and 1.5% by mole of diethylene glycol component as a dicarboxylic acid component Viscosity 0.7).

(Polyester E)

A polybutylene terephthalate resin (intrinsic viscosity: 1.22) having a terephthalate component as a dicarboxylic acid component of 100 mol% and a 1,4-butanediol component as a glycol component of 100 mol%.

(Particle Master A)

A polyethylene terephthalate particle master (intrinsic viscosity: 0.65) containing 2% by mass of a coagulated silica particle having an average particle diameter of 2.2 탆 in the polyester A at a particle concentration of 2% by mass.

(My Tutor Master)

Polyester A prepared as described above and 2,2 '- (1,4-phenylene) bis (4H-3,1 benzoxazin-4-one) were mixed at a mass ratio of 95: Kneaded at 280 DEG C by using an extruder to prepare an endurance master of 2,2 '- (1,4-phenylene) bis (4H-3,1 benzoxazin-4-one).

(Example 1)

Polyester A and polyester B were mixed at a mass ratio of 70:30 and fed to a vent twin screw extruder having an oxygen concentration of 0.2% by volume and melted at 275 캜 to remove foreign matters and homogenize the extruded amount , And discharged from the T-die onto a cooling drum controlled at a temperature of 25 DEG C as a sheet. At this time, electrostatic force was applied using a wire-shaped electrode having a diameter of 0.1 mm, and the film was brought into close contact with a cooling drum to obtain an unstretched film.

Then, before stretching in the longitudinal direction, the film temperature was elevated by a heating roll, and the preheating temperature was 85 캜, the stretching temperature was 90 캜, the stretching was 3 times in the longitudinal direction, and the film was then cooled with a metal roll controlled at 40 캜.

The following coating agents A, B, C, D, E, and F were mixed while dispersing by ultrasonication on the surface of the substrate film with a wet tension of 50 mN / 4 The metal ring was evenly coated.

A: Water-dispersed polyester resin (acid value: 4.5 mg / g)

B: methylol melamine (diluent: isopropyl alcohol / water)

C: oxazoline crosslinking agent (Nippon Shokuba now "EPOCROS" WS-500

D: colloidal silica (average particle diameter: 140 nm)

E: colloidal silica (average particle size 300 nm)

F: Fluorine surfactant (diluent: water)

Solid mass ratio: A / B / C / D / E / F

= 100 parts by mass / 38 parts by mass / 5 parts by mass / 2 parts by mass / 0.5 parts by mass / 0.2 parts by mass

Thereafter, the sheet was stretched 3.8 times in the transverse direction at a preheating temperature of 95 캜 and a stretching temperature of 100 캜 by a tenter type transverse stretching machine, followed by heat treatment at 230 캜 for 5 seconds while applying a relaxation of 4% Whereby a biaxially oriented polyester film having a film thickness of 188 mu m was obtained.

(Example 2)

The film of Example 1 was subjected to off-annealing treatment in a hot-air oven at 150 캜 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 3)

The film of Example 1 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in the width direction free state (state in which the film was not constrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 4)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 5)

The film of Example 4 was subjected to off-annealing treatment in a hot-air oven at 150 占 폚 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 6)

The film of Example 4 was subjected to an off-annealing treatment in a hot air oven at 180 캜 in a width direction free state (state in which the film was not restrained in the film width direction) and the winding speed in the longitudinal direction was reduced by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 7)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 8)

The film of Example 7 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in a width direction free state (state in which the film was not constrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 9)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 10)

The film of Example 9 was subjected to off-annealing treatment in a hot-air oven at 150 캜 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 11)

The film of Example 9 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 12)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 13)

The film of Example 12 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in a width direction free state (state in which the film was not constrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 14)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 15)

The film of Example 14 was subjected to an off-annealing treatment in a hot air oven at 180 캜 in a width direction free state (state in which the film was not constrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 16)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 17)

The film of Example 16 was subjected to off-annealing treatment in the width direction free state (state in which the film was not restrained in the film width direction) in a hot air oven at 180 캜 to control the winding tension in the longitudinal direction, Axis oriented polyester film.

(Example 18)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 19)

The film of Example 16 was subjected to off-annealing treatment in the width direction free state (state in which the film was not restrained in the film width direction) in a hot air oven at 180 캜 to control the winding tension in the longitudinal direction, Axis oriented polyester film.

(Example 20)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. . The obtained film was subjected to off-annealing treatment in a hot-air oven at 180 占 폚 in a width direction free state (state in which the film was not restrained in the film width direction) and the winding speed in the longitudinal direction was lowered by 1.5% Mu m of biaxially oriented polyester film.

(Example 21)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. . The obtained film was subjected to off-annealing treatment in a hot-air oven at 180 占 폚 in a width direction free state (state in which the film was not restrained in the film width direction) and the winding speed in the longitudinal direction was lowered by 1.5% Mu m of biaxially oriented polyester film.

(Example 22)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. . The obtained film was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% Mu m of biaxially oriented polyester film.

(Example 23)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. . The obtained film was subjected to off-annealing treatment in a hot-air oven at 180 占 폚 in a width direction free state (state in which the film was not restrained in the film width direction) and the winding speed in the longitudinal direction was lowered by 1.5% Mu m of biaxially oriented polyester film.

(Example 24)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 25)

The film of Example 24 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 26)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 27)

The film of Example 26 was subjected to an off-annealing process in a width direction free state (state in which the film was not restrained in the film width direction) in a hot air oven at 180 캜 while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 28)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 29)

The film of Example 28 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in a widthwise free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 30)

The oxygen concentration in the vent 2-axis extruder was set to 1 volume%, the extrusion temperature was set to 300 ° C, the stretching magnification in the longitudinal direction was set to 3.3 times, and the stretching magnification in the width direction was set to 3.7 times , A biaxially oriented polyester film having a film thickness of 188 탆 was obtained in the same manner as in Example 1. The obtained film was subjected to off-annealing treatment in a hot-air oven at 180 占 폚 in a width direction free state (state in which the film was not restrained in the film width direction) and the winding speed in the longitudinal direction was lowered by 1.5% Mu m of biaxially oriented polyester film.

(Example 31)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 32)

The film of Example 31 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 33)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 34)

The film of Example 33 was subjected to an off-annealing treatment in a hot air oven at 180 캜 in a width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 35)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 36)

The film of Example 35 was subjected to an off-annealing treatment in a hot-air oven at 180 캜 in the width direction free state (state in which the film was not restrained in the film width direction) while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 37)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 38)

The film of Example 37 was subjected to an off-annealing process in a width direction free state (state in which the film was not restrained in the film width direction) in a hot air oven at 180 DEG C while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Example 39)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Example 40)

The film of Example 39 was subjected to the off-annealing treatment in the width direction free state (state in which the film was not restrained in the film width direction) in the hot air oven at 180 캜 while the winding speed in the longitudinal direction was lowered by 1.5% A biaxially oriented polyester film having a thickness of 188 mu m was obtained.

(Comparative Example 1)

The composition and the film composition were changed as shown in Table 1, and a biaxially oriented polyester film having a film thickness of 188 탆 was obtained in the same manner as in Example 1.

(Comparative Example 2)

A biaxially oriented polyester film having a film thickness of 188 탆 was prepared in the same manner as in Example 1 except that the composition and the film composition were changed as shown in Table 1 and the stretching ratio in the longitudinal direction was 3.3 times and the stretching ratio in the width direction was 3.7 times. .

(Comparative Example 3)

The oxygen concentration in the vent 2-axis extruder was set at 1% by volume, the extrusion temperature was set at 285 ° C, the stretching magnification in the longitudinal direction was set at 3.3 times, and the stretching magnification in the width direction was set at 3.7 times , A biaxially oriented polyester film having a film thickness of 188 탆 was obtained in the same manner as in Example 1.

(Comparative Example 4)

The oxygen concentration in the vent 2-axis extruder was set to 1 volume%, the extrusion temperature was set to 300 ° C, the stretching magnification in the longitudinal direction was set to 3.3 times, and the stretching magnification in the width direction was set to 3.7 times , A biaxially oriented polyester film having a film thickness of 188 탆 was obtained in the same manner as in Example 1.

The meanings of abbreviations in the table are as follows.

EG: ethylene glycol

CHDM: 1,4-cyclohexanedimethanol

DEG: diethylene glycol

NPG: neopentyl glycol

TPA: terephthalic acid

IPA: isophthalic acid

(Industrial availability)

The biaxially oriented polyester film for molding of the present invention is molded by various molding methods such as vacuum molding, pressure molding, vacuum compression molding, and injection molding with in-mold molding because molding stress in the molding temperature range is low. In addition, since the storage elastic modulus in the processing temperature range is within a specific range, edibility can be performed by printing, vapor deposition or the like because of excellent dimensional stability in processing steps such as coating, laminating, printing and vapor deposition, It is excellent in heat resistance because it has a high storage elasticity in the region and exhibits excellent surface properties even after molding and has excellent color appearance and therefore has a good appearance. For example, it can be used for building materials, mobile devices, electric appliances, automobile parts, And can be suitably used for decorating molded parts such as parts.

Claims (14)

The stress (F100 value) at 100% elongation in the film longitudinal direction and the width direction at 150 占 폚 is 5 to 60 MPa, respectively, and the storage modulus at 80 占 폚 in the film longitudinal direction and the transverse direction is at least 2001 MPa And the storage elastic modulus at 180 占 폚 in the film longitudinal direction and the transverse direction is from 41 MPa to 400 MPa. The method according to claim 1,
And the color tone b value of the film is not less than -1.5 but not more than 1.5. 3. The method according to claim 1 or 2,
A polyester film having a polyester A layer and a polyester B layer, wherein the polyester A layer has a plane orientation coefficient of 0.14 or more and 0.17 or less, and the melting point (TmA) of the polyester A layer and the melting point Wherein the difference (TmA-TmB) of the melting point (TmB) is 7 占 폚 or more and 15 占 폚 or less, and the peak temperature of loss tangent is 100 占 폚 or more and 120 占 폚 or less. The method of claim 3,
The polyester A layer has a melting point (TmA) of 250 ° C to 255 ° C, and the polyester A layer has a density of 1.380g / cm 3 or more and 1.400g / cm 3 or less. The melting point (TmB) 235 占 폚 to 245 占 폚, and the density of the polyester B layer is 1.350 g / cm3 to 1.365 g / cm3. The method according to claim 1,
And the stress (F100 value) at 100% elongation in the film longitudinal direction and the transverse direction at 150 占 폚 is 5 to 36 MPa, respectively. The method according to claim 1,
A polyester film having a polyester A layer and a polyester B layer, wherein the polyester A layer contains 1 mol% or more and less than 5 mol% of a structural unit derived from 1,4-cyclohexane dimethanol,
Wherein the polyester B layer contains a structural unit derived from 1,4-cyclohexanedimethanol in an amount of 10 mol% or more and less than 15 mol%. The method according to claim 1,
Wherein the film has a melting point of 235 DEG C or more and 245 DEG C or less. The method according to claim 1,
Wherein the polyester A layer contains a structural unit derived from ethylene glycol in an amount of 95 mol% or more and less than 99 mol% based on the structural units derived from the diol, A structural unit derived from cyclohexanedimethanol is contained in an amount of 1 mol% or more and less than 5 mol%
A structural unit derived from ethylene glycol is contained in the polyester B layer in an amount of 85 mol% or more and less than 90 mol%, and a structural unit derived from 1,4-cyclohexane dimethanol in an amount of 10 mol% or more and less than 15 mol% Wherein the biaxially oriented polyester film for molding comprises a polyolefin resin. 9. The method of claim 8,
The polyester A layer contains 95 mol% or more and 100 mol% or less of structural units derived from terephthalic acid (including terephthalic acid ester) based on the structural units derived from dicarboxylic acid (including dicarboxylic acid ester)
Wherein the polyester B layer contains 95 mol% or more and 100 mol% or less of a structural unit derived from terephthalic acid with respect to a structural unit derived from a dicarboxylic acid (including a dicarboxylic acid ester) Axially oriented polyester film. The method according to claim 1,
The lamination ratio H (-) (H (-) :( thickness of A layer) (占 퐉) / (thickness of the entire film) (占 퐉)) of a polyester film having a polyester A layer and a polyester B layer Wherein the biaxially oriented polyester film for molding is 0.01 or more and 0.4 or less. The method according to claim 1,
A biaxially oriented polyester film for molding, characterized in that it is a laminated polyester film having a polyester A layer and a polyester B layer, wherein the polyester A layer is located on at least one outermost layer. The method according to claim 1,
And the heat shrinkage ratios in the longitudinal direction and in the width direction at 150 占 폚 are both -1% to 1% both inclusive. The method according to claim 1,
Wherein the film has a load of 19.6 mN and the film has a thermal strain of 0 to + 3% at 150 ° C in at least one direction when the temperature is raised from 25 ° C to 220 ° C at a heating rate of 5 ° C / Ester film. The method according to claim 1,
Wherein the film has a load of 19.6 mN and the film has a thermal strain of 0 to + 3% at 180 ° C in at least one direction when the temperature is raised from 25 ° C to 220 ° C at a heating rate of 5 ° C / Ester film.