JP4792693B2 - Polyester film for molding and dummy container obtained therefrom - Google Patents

Description

  The present invention is a molding polyester film suitable as a member of a dummy container, which is excellent in formability at low temperature, high sheet feeding stability and ink adhesion in a high-speed UV offset printing machine for multicolor printing, and capable of high-quality printing. And a dummy container obtained therefrom.

  Conventionally, as a sheet for processing, a polyvinyl chloride film is typical and has been preferably used in terms of workability. On the other hand, the film has problems such as generation of toxic gas when the film burns due to fire and the like, and problems such as bleed out of the plasticizer, and new materials have been demanded according to recent needs for environmental resistance.

  Such materials having excellent environmental resistance include copolymer components such as a long-chain linear aliphatic dicarboxylic acid component and / or a long-chain linear aliphatic glycol component having 3 or more carbon atoms. Many studies have been made to improve moldability by using polymerized polyester as a film raw material. However, since the polyester resin is softened by these copolymerization components, it is inferior in form stability (elasticity, strength, heat shrinkage characteristics, thickness variation, etc.) not only at the time of molding but also when actually used as a molded product. There was a drawback. On the other hand, if the composition ratio of the copolymer component is decreased in order to enhance the form stability, the moldability is lowered, and it is difficult to achieve both moldability, strength and elasticity.

For example, a polyester film made of polyester having neopentyl glycol or 1,4-cyclohexanedimethanol as a copolymerization component is known as the copolymer polyester (see, for example, Patent Documents 1 and 2). Since the copolymer polyester films described in these conventional techniques have a thickness of 50 μm or less, film formation is relatively easy.
JP-A-1-252658 Japanese Unexamined Patent Publication No. 1-445699

  However, when the thickness of the film exceeds 50 μm, the copolyester inherently has a tendency of insufficient control of molecular orientation from the viewpoint of stress reduction during stretching and crystallinity, and elasticity. And form stability may be insufficient. Therefore, when using the obtained molded product in a normal temperature atmosphere while maintaining moldability, a polyester film excellent in elasticity and shape stability (heat shrinkage characteristics, thickness unevenness) has been desired.

  Moreover, in order to improve the designability of molded products, printing is often performed on the film surface before the film is molded. Since such a printing layer is often applied to the back side of a molding film, it is desired that the transparency of the film is high from the viewpoint of printing clarity. However, since the conventional film for molding has low transparency, there is a problem that the printed appearance is deteriorated or the backlight is difficult to transmit and the visibility is poor.

In order to deal with such problems, a film in which a copolyester containing an aliphatic dicarboxylic acid having improved moldability at 150 ° C. is biaxially oriented has been proposed (for example, see Patent Document 3). However, the film disclosed in Patent Document 3 tends to have insufficient heat resistance when trying to improve moldability at 150 ° C. Further, the thickness unevenness of the film was insufficient.
Japanese Patent Laid-Open No. 3-67629

Therefore, in order to achieve both moldability and heat resistance, (a) a polyethylene terephthalate film biaxially stretched at a relatively low magnification, or (b) a polyethylene terephthalate blended with polypropylene terephthalate or polybutylene terephthalate, a relatively low magnification. And a biaxially stretched film has been proposed (see, for example, Patent Document 4). However, in this method, if the moldability is improved while maintaining the heat resistance, the transparency of the film tends to decrease.
JP 2001-347565 A

  That is, in the prior art, a film satisfying all of the heat resistance, transparency, and moldability in a balanced manner has not been obtained so far.

  In addition, the film disclosed in the prior art does not satisfy the market demand in terms of low-temperature formability, and its improvement has been strongly desired. A conventional polyester film needs to be heated to about 150 ° C. in order to obtain moldability. However, at this temperature, the finished product of the molded product may be hindered due to the dimensional change accompanying the thermal contraction of the film. Moreover, since it is necessary to make the accompanying printing ink and protective film into a heat resistant type, there is a problem that the selection of the material is greatly restricted. On the other hand, if the film can be molded at a relatively low temperature of about 120 ° C., there is an advantage that the problem of the dimensional change rate due to the thermal shrinkage of the film is reduced and the limitation of the material used in combination is reduced. Moreover, it can contribute to energy saving by providing low temperature moldability.

On the other hand, in a vending machine for beverages in bottles and cans, dummy containers are displayed instead of actual containers as sample products. Conventionally, a plastic container that faithfully copies the actual product has been used. As these dummy container films, a heat-shrinkable polyester film intended for surface decoration of a container having a complicated shape is disclosed (for example, see Patent Document 5).
JP-A-4-199397

  However, in recent years, in response to demands for space saving and the like of vending machines, the dummy container is also being switched from a fully imitated type to a partially imitated type. That is, in the case of the dummy container, it is only necessary to understand the contents of the product when viewed from substantially the front. The partially-shaped dummy container is produced by, for example, molding a printed polyester film into a substantially half shape by press molding or the like. Therefore, the display subspace can be reduced by the correspondence, and the economy is greatly improved. However, in recent years, beverage containers have become more sophisticated, the container shape has become more complex, and the printing on the surface layer has become more demanding for complicated and fine prints. With conventional polyester films, moldability and printability have increased. In this respect, it has become impossible to meet market demands sufficiently.

  The object of the present invention is to eliminate the above-mentioned problems of the prior art, moldability at the time of heat molding, elasticity and shape stability (heat shrinkage characteristics, thickness unevenness) when used in a room temperature atmosphere as a molded product, and transparency Polyester film for molding that excels in molding, especially molding polyester film that has excellent formability at low temperatures and high sheet-feed stability and ink adhesion in a high-speed UV offset printing machine for multicolor printing, and can be obtained from it. Is to provide a dummy container.

The present invention has the following configuration.
1. A polyester film that does not substantially contain particles is used as a base material, and a coating layer A containing an adhesive modified resin and particles is laminated on one side of the base material, and a coating layer B containing particles and wax is laminated on the other side. A polyester film for molding, wherein the base material includes a copolymerized polyester synthesized from an aromatic dicarboxylic acid component and ethylene glycol and a glycol component containing a branched aliphatic glycol and / or an alicyclic glycol. It consists of a polyester film having a melting point (Tm) of 220 ° C. or higher and lower than 245 ° C., the branched aliphatic glycol is neopentyl glycol, the alicyclic glycol is 1,4-cyclohexanedimethanol, and has a thickness (d The ratio (H / d) of haze (H) to 0) is more than 0 and not more than 0.01% / μm, in the longitudinal direction and the width direction. 100% elongation stress at the kicking is molding a polyester film, wherein the at 1MPa or more 100MPa or less at 180MPa and less than 100 ° C. or higher 10MPa at 25 ° C..
2. 2. The polyester film for molding according to 1 above, wherein the film has a thickness unevenness of 5.5% or less.
3. 3. The polyester film for molding according to 1 or 2 above, wherein the film has a heat shrinkage rate of not more than 6.0% in the longitudinal direction and the width direction at 150 ° C.
4). The coating layer A is (a) a polyester-based graft copolymer obtained by grafting an acid anhydride having at least one double bond to a hydrophobic copolymerized polyester resin, and (b) an average particle size of 1.0 to The polyester film for molding according to any one of claims 1 to 3, comprising a composition containing 5.0 µm particles.
5. The coating layer B comprises (c) a copolyester resin, (d) a compound having a sulfonate group, (e) particles having an average particle diameter of 1.0 to 5.0 μm, and (f) a polymer wax. 5. The molding polyester film as described in any one of 1 to 4 above, which comprises a composition containing the same.
6). The polyester film for molding according to any one of 1 to 5 above, wherein both the static friction coefficient and the dynamic friction coefficient when the coating layer A and the coating layer B are overlapped are 0.5 or less.
7). A dummy container obtained from the molding polyester film according to claim 1.

  In the polyester film for molding of the present invention, the stress at 100% elongation in the longitudinal direction and the width direction of the film is independently controlled at 25 ° C. and 100 ° C., and the moldability during heating, particularly the moldability at low temperature, It is excellent in elasticity and shape stability (thickness unevenness, heat shrinkage characteristics) when used as a molded product. Furthermore, since the substrate is excellent in transparency and the coating layer A is laminated on one side of the substrate film and the coating layer B is laminated on the other side, in addition to the easy moldability described above, high-speed UV offset printing for multicolor printing It is excellent in paper feeding stability and ink adhesion in the machine, and can perform high-quality printing at high speed.

  The polyester film for molding according to the present invention contains a copolymer polyester composed of an aromatic dicarboxylic acid component and ethylene glycol and a glycol component containing a branched aliphatic glycol and / or an alicyclic glycol in the base film. . The branched aliphatic glycol and / or alicyclic glycol has a side chain or cyclic structure that suppresses mobility such as free rotation of the molecule, and glass is obtained by copolymerizing such monomers. The melting point (Tm) can be lowered and the elongation at break can be increased without lowering the transition temperature (Tg).

  The molding polyester film of the present invention using such a copolymerized polyester as a raw material for the base film is excellent in moldability at low temperatures and has a form stability (elasticity) in a normal temperature atmosphere used as a molded product. , Strength, heat shrinkage characteristics, thickness variation), and is a polyester film particularly suitable for molding applications.

  The above-mentioned features can be expressed by physical properties such that the stress at 100% elongation in the longitudinal direction and the width direction is 10 MPa or more and less than 180 MPa at 25 ° C. and 1 MPa or more and 100 MPa or less at 100 ° C.

  100% elongation stress at 25 ° C. in the longitudinal direction and width direction of the film achieves both form stability (elasticity, strength, thickness variation, thermal shrinkage at 150 ° C.) and moldability at low temperature. From the point, it is important that the pressure is 10 MPa or more and less than 180 MPa.

  On the other hand, in the case of a highly elastic film having a stress at 100% elongation in the atmosphere of 25 ° C. exceeding 180 MPa, the moldability at the time of heat molding, particularly the moldability at a low temperature, is likely to deteriorate.

  From the viewpoint of moldability, it is important that the stress at 100% elongation in the longitudinal direction and the width direction of the film in an atmosphere at 100 ° C. is 1 MPa or more and 100 MPa or less.

  The lower limit value of the stress at 100% elongation in the 100 ° C. atmosphere is preferably 5 MPa, particularly preferably 10 MPa. In a field where high deformability is required, a small stress at 100% elongation in an atmosphere of 100 ° C. is a desirable direction from the viewpoint of moldability. However, if the stress at 100% elongation in a 100 ° C. atmosphere becomes too small, the stress at 100% elongation at 25 ° C. also decreases, and the elasticity and thickness unevenness in a normal temperature atmosphere deteriorate. It is important to set the lower limit of the stress at 100% elongation of 5 MPa to 5 MPa.

  On the other hand, the stress at 100% elongation at 100 ° C. is preferably 90 MPa or less, particularly preferably 80 MPa or less, from the viewpoint of moldability during heat molding.

  From the viewpoint of moldability, the breaking elongation at 100 ° C. is preferably 150% or more, more preferably 170% or more, and particularly preferably 200% or more.

  From the viewpoint of morphological stability (elasticity, strength, heat shrinkage characteristics, thickness unevenness), the elongation at break at 25 ° C. is preferably 130% or more, more preferably 150% or more, particularly preferably. 170% or more.

  In the present invention, the change rate of the stress at the time of 100% elongation in the longitudinal direction and the width direction at 100 ° C. ((1 month after film formation-immediately after film formation) × 100 / immediately after film formation) However, it is preferable that both are ± 20% or less. More preferably, it is ± 10% or less, and particularly preferably ± 5% or less.

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

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

  In the molding polyester film of the present invention, the thickness of the base film is preferably 50 to 500 μm from the viewpoints of moldability, stiffness (waist), protection of the printed layer provided on the back surface of the molded film, and design properties. The lower limit value of the thickness of the base film is preferably 60 μm, particularly preferably 70 μm. On the other hand, the upper limit of the thickness of the base film is preferably 300 μm, particularly preferably 200 μm.

  Moreover, it is preferable that the uneven thickness of the polyester film for molding of the present invention is 5.5% or less. If the thickness unevenness exceeds 5.5%, the printability and dimensional stability tend to deteriorate. It is desirable that the thickness unevenness is small, but it is technically difficult to make the thickness unevenness 0.5% or less, and since there is no significant difference in practical quality, the lower limit of the thickness unevenness is 0. .5% is acceptable.

  Furthermore, the polyester film for molding of the present invention preferably has a heat shrinkage rate of 150% or less in the longitudinal direction and the width direction of 6.0% or less from the viewpoint of reducing printing misalignment.

  Since the polyester film for molding of the present invention is formed by laminating a coating layer A containing an adhesion modifying resin on one side of the above base film and a coating layer B containing particles and / or wax on the other side, The high-speed UV offset printing machine is excellent in sheet feeding stability and ink adhesion, and enables high-quality printing.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The polyester in the present invention means a general term for high molecular weight substances constituted by ester bonds.

  In the molding polyester film of the present invention, a copolymer polyester composed of an aromatic dicarboxylic acid component and ethylene glycol and a glycol component containing a branched aliphatic glycol and / or an alicyclic glycol is used as a base film raw material. Use as part or 100%.

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

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

  Among these, neopentyl glycol and 1,4-cyclohexanedimethanol are particularly preferable, and the stress at 100% elongation in the longitudinal direction and the width direction of the film defined in the present invention is 10 MPa or more and less than 180 MPa and 100 ° C. at 25 ° C. It is effective to satisfy 1 MPa or more and 100 MPa or less. Furthermore, it is excellent not only in moldability and transparency, but also in heat resistance, which is preferable from the viewpoint of improving adhesion with the coating layers A and B.

  Furthermore, you may use together the following dicarboxylic acid component and / or glycol component as a copolymerization component in the said copolyester as needed, if necessary.

  Other dicarboxylic acid components that can be used in combination with terephthalic acid or its ester-forming derivatives include (1) isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, diphenoxyethanedicarboxylic acid Aromatic dicarboxylic acids such as acid, diphenylsulfone dicarboxylic acid, 5-sodium sulfoisophthalic acid, phthalic acid or their ester-forming derivatives, (2) oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid Aliphatic dicarboxylic acids such as fumaric acid and glutaric acid or ester-forming derivatives thereof; (3) alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid or ester-forming derivatives thereof; (4) p-oxybenzoic acid; Oxycarboxylic acids such as oxycaproic acid or their esthetics Forming derivatives, and the like.

  On the other hand, examples of other glycol components that can be used together with ethylene glycol and branched aliphatic glycol and / or alicyclic glycol include 1,3-propanediol, 1,4-butanediol, pentanediol, and hexane. Examples include aliphatic glycols such as diols, aromatic glycols such as bisphenol A and bisphenol S, and ethylene oxide adducts thereof, diethylene glycol, and triethylene glycol.

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

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

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

  The copolymer polyester preferably has an intrinsic viscosity of 0.50 to 1.0 dl / g from the viewpoints of moldability, adhesiveness, and film formation stability. The upper limit of the intrinsic viscosity of the copolyester is preferably 0.95 dl / g, particularly preferably 0.90 dl / g, from the viewpoint of ejection stability from the extruder. On the other hand, the lower limit is preferably 0.55 dl / g, particularly preferably 0.60 dl / g, from the viewpoint of film-forming stability and mechanical strength. Moreover, as a polyester film for shaping | molding, the intrinsic viscosity of the range of 0.60-0.80 dl / g is preferable from the point of a moldability.

  The base film in the polyester film for molding of the present invention may use the copolymer polyester as a film raw material as it is, or blend a copolymer polyester having a high ratio of copolymer components with a homopolyester, May be adjusted.

  Moreover, it is preferable from the point of a moldability to blend 2 or more types of the said copolyester, and to use as a raw material of the base film in the polyester film for shaping | molding of this invention. Among these, a mixed polymer obtained by blending polyneopentene terephthalate and / or polycyclohexanedimethylene terephthalate with polyethylene terephthalate is particularly preferable from the viewpoint of flexibility and moldability.

The melting point of the polyester base film is preferably 220 to 245 ° C. from the viewpoint of heat resistance and moldability. In order to control the melting point of the polyester base film to 220 to 245 ° C., it is preferable to adjust the type and composition of the copolymerization component for the polyester. Here, the melting point is an endothermic peak temperature at the time of melting, which is detected at the time of primary temperature rise in so-called differential scanning calorimetry (DSC). The DSC was measured by using a differential scanning calorimeter (DuPont, V4.OB2000 type) at a temperature of 20 ° C./min.

  The melting point of the polyester base film is more preferably a lower limit of 225 ° C., particularly preferably 230 ° C., from the viewpoint of heat resistance. If the melting point is less than 220 ° C, the heat resistance tends to deteriorate. Therefore, it may become a problem when exposed to high temperature during molding or use of a molded product.

The melting point should be higher from the viewpoint of heat resistance, but when a polyethylene terephthalate unit is the main component, it is difficult to ensure transparency with a film having a melting point exceeding 245 ° C. in order to ensure high transparency and flexibility. . Therefore, it is important to lower the melting point by adjusting the ratio of the copolymer component of the copolymer polyester, and the upper limit of the melting point of the copolymer polyester is preferably 245 ° C. Furthermore, when it is necessary to increase transparency, the upper limit of the melting point of the copolyester is set to 240 ° C.

In order to satisfy all of transparency, flexibility, and heat resistance, for example, it is preferable to melt and mix a high melting point polyester (PET) and a low melting point copolymer polyester. By forming a film using the melt blending method, transparency and high melting point (heat resistance) are achieved while maintaining the same flexibility as when using only copolymer polyester, and only high-melting polyester is used. In this case, it is possible to achieve flexibility and a melting point (heat resistance) having no practical problem while maintaining high transparency.

  Further, it is preferable to form irregularities on the film surface in order to improve handling properties such as slipperiness and winding property of the film. As a method for forming irregularities on the film surface, a method of incorporating particles in the film is generally used. However, since the particles contained in the film generally have a refractive index different from that of polyester, it causes a decrease in the transparency of the film.

  Therefore, in order to increase the transparency of the film while maintaining the handleability of the film, it is effective to make the base film contain substantially no particles, but only the thin surface layer contains particles. is there. The thin surface layer can be formed by a coating method or a coextrusion method. By setting it as such a laminated structure, ratio (H / d) of haze H (%) with respect to the thickness d (micrometer) of a film can be made into less than 0.010, maintaining the handling property of a film. Especially, in the case of a coating method, since the adhesiveness with a printing layer can be improved by using the composition which consists of resin containing particle | grains as an application layer, it is a preferable method.

  The phrase “substantially contain no particles in the base film” as used above means, for example, in the case of inorganic particles, a content that is below the detection limit when inorganic elements are quantified by fluorescent X-ray analysis. . This is because even if the particles are not intentionally included in the base film, contaminants derived from foreign substances may be mixed.

  Examples of the particles contained in the surface layer include inorganic particles and / or organic particles having an average particle size of 0.01 to 10 μm. These inorganic particles and / or organic particles may be used in combination of two or more as required.

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

  When the surface layer contains particles having an average particle diameter exceeding 10 μm, the frequency of forming coarse protrusions on the film surface increases, and the design property tends to deteriorate. On the other hand, in the case of particles having an average particle diameter of less than 0.01 μm, handling properties such as film slipperiness and winding property tend to be lowered.

  Examples of the inorganic particles include wet method silica, dry method silica, colloidal silica, glass filler, titanium oxide, alumina, aluminum silicate, mica, kaolin, clay, zeolite, alumina-silica composite oxide particles, hydroxyapatite, carbonic acid. Examples include calcium, calcium phosphate, and barium sulfate.

  Examples of organic particles include particles containing styrene, silicone, acrylic acid, methacrylic acid, polyester, divinylbenzene and the like as constituent components.

  Among these particles, silica particles, glass fillers, and silica-alumina composite oxide particles are particularly suitable from the viewpoint of transparency because the refractive index is relatively close to that of polyester.

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

  The polyester base film used in the present invention is preferably an unstretched film for applications that require severe moldability. From the viewpoint of heat resistance and dimensional stability, a biaxially stretched polyester film is preferred. Such a biaxial stretching method may be either simultaneous biaxial stretching or sequential biaxial stretching.

  The polyester base film can be made into a laminated structure by a known method using different types of polyester. The laminated structure of the base film is not particularly limited, and examples thereof include A / B type 2 layers, B / A / B type 2 layers, C / A / B type 3 layers, and the like.

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

  Such a stretching method may be either simultaneous biaxial stretching or sequential biaxial stretching. In short, the unstretched sheet is stretched and heat-treated in the longitudinal direction (MD) and the width direction (TD) of the film, and the intended surface. A method of obtaining a biaxially stretched film having an internal orientation degree is employed. Among these methods, in terms of film quality, the MD / TD method in which the film is stretched in the longitudinal direction and then stretched in the width direction, or the TD / MD method in which the film is stretched in the width direction and then stretched in the longitudinal direction. An axial stretching method and a simultaneous biaxial stretching method in which the longitudinal direction and the width direction are stretched almost simultaneously are desirable. Furthermore, if necessary, a multistage stretching method in which stretching in the same direction is performed in multiple stages may be used.

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

  In the polyester film for molding of the present invention, as a raw material for the base film, (1) a copolymer polyester comprising terephthalic acid and ethylene glycol or neopentyl glycol, or (2) terephthalic acid and ethylene glycol, 1,4-cyclohexanedi When using a copolymer polyester made of methanol, the stretching ratio in the longitudinal direction is such that the stress at 100% elongation in the longitudinal direction and the width direction is 10 MPa or more and less than 180 MPa at 25 ° C. and 1 MPa or more and 100 MPa or less at 100 ° C. Is preferably 2.8 to 4.0 times, and the draw ratio in the width direction is preferably 3.0 to 4.5 times.

  The stretching conditions for producing the molding polyester film of the present invention are not particularly limited. However, in order to satisfy the range of stress at 100% elongation at 25 ° C. and 100 ° C. specified in the present invention, in the longitudinal stretching step, for example, the stretching temperature is preferably set so that the subsequent lateral stretching can be performed smoothly. 50 to 110 ° C., particularly preferably 80 to 100 ° C., and the draw ratio is preferably 1.5 to 4.0 times, particularly preferably 2.5 to 3.8 times.

  In the transverse stretching, stress at 100% elongation in the longitudinal direction and the width direction is particularly important because it is 10 MPa or more and less than 180 MPa at 25 ° C. and 1 MPa or more and 100 MPa or less at 100 ° C.

  Usually, when stretching the polyethylene terephthalate, if the stretching temperature is lower than the appropriate conditions, the yield stress increases rapidly at the beginning of the lateral stretching, and therefore stretching cannot be performed. Moreover, even if it can extend | stretch, since thickness and a draw ratio become easy to become nonuniform, it is unpreferable.

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

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

  Such a phenomenon is likely to occur when the thickness of the film is 60 to 500 μm, and is particularly noticeable in a film having a thickness of 100 to 300 μm. Therefore, for example, in the case of a film using polyester copolymerized with neopentyl glycol or 1,4-cyclohexanedimethanol, the stretching temperature in the transverse direction is preferably set as follows.

  First, the preheating temperature is 90 to 120 ° C., the stretching temperature is +5 to 25 ° C. with respect to the preheating temperature in the first half of the transverse stretching, and the stretching temperature is − with respect to the stretching temperature of the first half in the latter half of the transverse stretching. A range of 15 to -40 ° C is preferred. By adopting such conditions, the first half of the transverse stretching is easy to stretch because the yield stress is small, and the second half is easily oriented. In addition, it is preferable that the draw ratio of a horizontal direction shall be 2.5 to 5.0 times. As a result, it is possible to obtain a film satisfying a stress at 100% elongation in the longitudinal direction and the width direction of 10 MPa to less than 180 MPa at 25 ° C. and 1 MPa to 100 MPa at 100 ° C.

  Further, the film is subjected to heat treatment after biaxial stretching, and this heat treatment can be performed by a conventionally known method such as in an oven or on a heated roll. The heat treatment temperature and the heat treatment time can be arbitrarily set according to the required level of heat shrinkage. The heat treatment temperature is preferably in the range of 120 to 245 ° C, particularly preferably 150 to 230 ° C. The heat treatment time is preferably 1 to 60 seconds. In addition, you may perform this heat processing, relaxing a film to the longitudinal direction and / or the width direction. In order to reduce the thermal shrinkage in the longitudinal direction and the lateral direction at 150 ° C., it is preferable to increase the heat treatment temperature, lengthen the heat treatment time, and perform relaxation treatment. It is difficult to lengthen the line and increase the heat treatment time due to equipment limitations. Moreover, it is not preferable to slow the film feeding speed because the productivity is lowered.

  The polyester film for molding of the present invention needs to be formed by laminating a coating layer A containing an adhesive modifying resin on one side of the base material and a coating layer B containing particles and / or wax on the other side. With this configuration, it is possible to achieve high-quality printing with excellent paper feeding stability and ink adhesion in a high-speed UV offset printing press for multicolor printing. For example, a high-quality printing surface such as a dummy container and economical printing are required. To meet the market demands of the selected fields.

  In the present invention, the composition of the coating layer A is not limited as long as it has a function of improving the printability of the polyester film for molding the base material, but the coating layer A is (a) A composition comprising a polyester-based graft copolymer obtained by grafting an acid anhydride having at least one double bond to a hydrophobic copolymerized polyester resin, and (b) particles having an average particle size of 1.0 to 5.0 μm. It is a preferred embodiment that it consists of a product.

  In the present invention, the coating layer B is not particularly limited as long as it has a function of improving the slipperiness of the polyester film for molding the base material, but (c) a copolyester resin, A preferred embodiment is composed of a composition containing (d) a compound having a sulfonate group, (e) particles having an average particle diameter of 1.0 to 5.0 μm, and (f) a polymer wax.

  A polyester-based graft copolymer obtained by grafting an acid anhydride having at least one double bond to the hydrophobic copolymerized polyester resin will be described in detail.

  The “grafting” of the polyester-based graft copolymer in the present invention is to introduce a branched polymer composed of a polymer different from the main chain into the main chain of the main polymer. Graft polymerization is generally carried out by reacting at least one radical polymerizable monomer using a radical initiator in a state where a hydrophobic copolyester resin is dissolved in an organic solvent.

  The reaction product after completion of the grafting reaction includes a graft copolymer of a desired hydrophobic copolymerized polyester resin and a radically polymerizable monomer, a hydrophobic copolymerized polyester resin not subjected to grafting, and a hydrophobic polymer. It also contains a radical polymerizable monomer that has not been grafted to the copolymerizable polyester resin. The polyester-based graft copolymer in the present invention includes not only the above-mentioned polyester-based graft copolymer, but also a hydrophobic copolymerized polyester resin that has not been grafted, and a radically polymerizable monomer that has not been grafted. A reaction mixture including a monomer and the like is also included.

In the present invention, the acid value of a reaction product obtained by graft polymerization of a radically polymerizable monomer to a hydrophobic copolyester resin is preferably 600 eq / 10 ⁶ g or more. More preferably, the acid value of the reactant is 1200 eq / 10 ⁶ g or more. When the acid value of the reaction product is less than 600 eq / 10 ⁶ g, the adhesion with the printing layer applied to the primer layer (application layer A in the present invention) tends to be insufficient.

  The mass ratio of the desired hydrophobic copolymerized polyester resin and the radical polymerizable monomer suitable for the purpose of the present invention is preferably in the range of polyester / radical polymerizable monomer = 40/60 to 95/5, The range is desirably 55/45 to 93/7, and most desirably 60/40 to 90/10.

  When the mass ratio of the hydrophobic copolymerized polyester resin is less than 40% by mass, the excellent adhesion of the polyester resin cannot be exhibited. On the other hand, when the mass ratio of the hydrophobic copolyester resin is larger than 95% by mass, blocking, which is a defect of the polyester resin, easily occurs.

  The graft polymerization reaction product of the present invention is in the form of an organic solvent solution or dispersion or an aqueous solvent solution or dispersion. In particular, a dispersion of an aqueous solvent, that is, a form of a water-dispersed resin is preferable in terms of working environment and applicability. In order to obtain such a water-dispersed resin, a radically polymerizable monomer containing a hydrophilic radically polymerizable monomer is usually graft-polymerized to the hydrophobic copolymerized polyester resin in an organic solvent. This is achieved by adding water and distilling off the organic solvent.

  The water-dispersed resin in the present invention has an average particle diameter measured by a laser light scattering method of 500 nm or less and exhibits a translucent or milky white appearance. By adjusting the polymerization method, water-dispersed resins with various particle sizes can be obtained. The particle size is suitably 10 to 500 nm, and is preferably 400 nm or less, more preferably 300 nm or less in terms of dispersion stability. . When the average particle diameter exceeds 500 nm, the gloss of the coating film surface is lowered, and the transparency of the coating is lowered. When the average particle diameter is less than 10 nm, the water-resistant adhesion tends to be lowered.

  The hydrophilic radical polymerizable monomer used for the polymerization of the water-dispersed resin in the present invention means a radical polymerizable monomer having a hydrophilic group or a group that can be changed to a hydrophilic group later. Examples of the radical polymerizable monomer having a hydrophilic group include a radical polymerizable monomer containing a carboxyl group, a hydroxyl group, a phosphoric acid group, a phosphorous acid group, a sulfonic acid group, an amide group, a quaternary ammonium base and the like. be able to.

  On the other hand, examples of the radical polymerizable monomer having a group that can be changed to a hydrophilic group include radical polymerizable monomers containing an acid anhydride group, a glycidyl group, a chloro group, and the like. Among these, from the viewpoint of water dispersibility, a carboxyl group is preferable, and a radical polymerizable monomer having a carboxyl group or a group capable of generating a carboxyl group is preferable.

  In view of increasing the acid value of the present invention, it is preferable that a radical polymerizable monomer containing a carboxyl group or having a group capable of generating a carboxyl group is contained.

  The glass transition temperature of the graft copolymer is not particularly limited, but is preferably 20 ° C. or higher, more preferably 40 ° C. or higher in relation to adhesion in a high temperature and high humidity environment.

  In the present invention, the hydrophobic copolyester resin needs to be essentially water-insoluble which does not inherently disperse or dissolve in water. When a polyester resin that is dispersed or dissolved in water is used for graft polymerization, adhesion and water-resistant adhesion deteriorate.

  The composition of the dicarboxylic acid component of this hydrophobic copolyester resin is as follows: aromatic dicarboxylic acid 60 to 99.5 mol%, aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid 0 to 40 mol%, polymerizable unsaturated dicarboxylic acid. It is preferable that it is 0.5-10 mol% of dicarboxylic acid containing a heavy bond. When the aromatic dicarboxylic acid is less than 60 mol%, or when the aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid exceeds 40 mol%, the adhesive strength tends to decrease.

  Moreover, when the dicarboxylic acid containing a polymerizable unsaturated double bond is less than 0.5 mol%, it becomes difficult to carry out efficient grafting of the radical polymerizable monomer to the polyester resin. If it exceeds 1, the viscosity will increase too late in the grafting reaction, which tends to hinder the uniform progress of the reaction. More preferably, the aromatic dicarboxylic acid is 70 to 98 mol%, the aliphatic dicarboxylic acid and / or the alicyclic dicarboxylic acid is 0 to 30 mol%, and the dicarboxylic acid containing a polymerizable unsaturated double bond is 2 to 7 mol%. It is.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, and biphenyl dicarboxylic acid. It is preferable not to use a hydrophilic group-containing dicarboxylic acid such as 5-sodiumsulfoisophthalic acid from the viewpoint that the water-resistant adhesion decreases.

  Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid. Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid. 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid and acid anhydrides thereof.

  Examples of dicarboxylic acids containing polymerizable unsaturated double bonds include α, β-unsaturated dicarboxylic acids such as fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, unsaturated double bonds As examples of the alicyclic dicarboxylic acid containing 2,5-norbornene dicarboxylic acid anhydride and tetrahydrophthalic anhydride can be given. Of these, fumaric acid, maleic acid and 2,5-norbornene dicarboxylic acid are preferred from the viewpoint of polymerizability.

  On the other hand, the glycol component is composed of an aliphatic glycol having 2 to 10 carbon atoms and / or an alicyclic glycol having 6 to 12 carbon atoms and / or an ether bond-containing glycol. For example, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1 , 5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol, and examples of the alicyclic glycol having 6 to 12 carbon atoms include 1,4-cyclohexanedimethanol. Can be mentioned.

  Examples of the ether bond-containing glycol include diethylene glycol, triethylene glycol, dipropylene glycol, and glycols obtained by adding ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols, such as 2,2- Bis (4-hydroxyethoxyphenyl) propane can be mentioned. Polyethylene glycol, polypropylene glycol, and polytetramethylene glycol can also be used as necessary.

  In the copolymerized polyester resin used in the present invention, 0 to 5 mol% of a tri- or higher functional polycarboxylic acid and / or polyol can be copolymerized. Trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, trimesic acid, ethylene glycol bis (anhydro trimellitate), glycerol tris (anhydro trimellitate) are used. On the other hand, as the trifunctional or higher functional polyol, for example, glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol are used. The tri- or higher functional polycarboxylic acid and / or polyol is copolymerized in the range of 0 to 5 mol%, preferably 0 to 3 mol%, more than 5 mol% with respect to the total acid component or the total glycol component. And gelation during polymerization tends to occur, which is not preferable.

  The hydrophobic copolyester resin preferably has a weight average molecular weight in the range of 5,000 to 50,000. If the weight average molecular weight is less than 5,000, the adhesive strength tends to decrease, and conversely if it exceeds 50,000, problems such as gelation during polymerization tend to occur.

  Examples of the polymerizable unsaturated monomer used in the present invention include (1) fumaric acid, monoethyl fumarate, diethyl fumarate, monoester or diester of fumaric acid such as dibutyl fumarate, and (2) maleic acid and its Anhydrides, monoesters or diesters of maleic acid such as monoethyl maleate, diethyl maleate, dibutyl maleate, (3) Itaconic acid and its anhydride, monoesters or diesters of itaconic acid, (4) maleimides such as phenylmaleimide (5) Styrene derivatives such as styrene, α-methyl styrene, t-butyl styrene, chloromethyl styrene, and other examples include vinyl toluene and divinyl benzene.

  Examples of the acrylic polymerizable monomer include alkyl acrylate and alkyl methacrylate (wherein the alkyl group is methyl group, ethyl group, N-propyl group, isopropyl group, N-butyl group, isobutyl group, t- Butyl group, 2-ethylhexyl group, cyclohexyl group, phenyl group, benzyl group, phenylethyl group, etc.); hydroxy-containing such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate Acrylic monomer; acrylamide, methacrylamide, N-methyl methacrylamide, N-methyl acrylamide, N-methylol acrylamide, N-methylol methacrylamide, N, N-dimethylol acrylamide, N-meth Amide group-containing acrylic monomers such as cymethylacrylamide, N-methoxymethylmethacrylamide and N-phenylacrylamide; Amino group-containing acrylic monomers such as N, N-diethylaminoethyl acrylate and N, N-diethylaminoethyl methacrylate; Epoxy group-containing acrylic monomers such as glycidyl acrylate and glycidyl methacrylate; acrylic monomers containing carboxyl groups such as acrylic acid, methacrylic acid and their salts (sodium salt, potassium salt, ammonium salt) or salts thereof It is done. Preferred are maleic anhydride and esters thereof. The said monomer can be copolymerized using 1 type, or 2 or more types.

  The graft polymerization of the present invention is generally carried out by reacting a radical initiator and a radical polymerizable monomer mixture in a state where a hydrophobic copolyester resin is dissolved in an organic solvent. The reaction product after completion of the grafting reaction includes a graft copolymer between the hydrophobic copolymerized polyester resin and the radical polymerizable monomer mixture, a hydrophobic copolymerized polyester resin that has not undergone grafting, and a hydrophobic polymer. Although the radical polymer which was not grafted to the copolyester resin is also contained, the graft polymer in the present invention includes all of them.

  Examples of the graft polymerization initiator used in the present invention include organic peroxides and organic azo compounds known to those skilled in the art.

  Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxypivalate, and examples of the organic azo compound include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2, 4-dimethyl pareronitrile).

  The amount of the polymerization initiator used for graft polymerization is at least 0.2% by mass, preferably 0.5% by mass or more, based on the radical polymerizable monomer.

  In addition to the polymerization initiator, a chain transfer agent for adjusting the chain length of the branched polymer, for example, octyl mercaptan, mercaptoethanol, 3-t-butyl-4-hydroxyanisole may be used as necessary. In this case, it is desirable to add in the range of 0 to 5% by mass with respect to the polymerizable monomer.

  The grafting reaction solvent used in the present invention is preferably composed of an aqueous organic solvent having a boiling point of 50 to 250 ° C. The aqueous organic solvent means a solvent having a solubility in water at 20 ° C. of at least 10 g / L or more, desirably 20 g / L or more. Those having a boiling point exceeding 250 ° C. are not suitable because the evaporation rate is extremely slow and it is difficult to sufficiently remove even by high-temperature baking of the coating film.

  Further, when the boiling point of the aqueous organic solvent is less than 50 ° C., when the grafting reaction is carried out using the solvent as a solvent, it is necessary to use an initiator that cleaves into radicals at a temperature of less than 50 ° C. Increased and undesirable.

  As the first group of aqueous organic solvents that can dissolve the copolymer polyester resin well and can dissolve the polymerizable monomer mixture containing the carboxyl group-containing polymerizable monomer and the polymer thereof relatively well, For example, esters such as ethyl acetate; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; cyclic ethers such as tetrahydrofuran, dioxane and 1,3-dioxolane; ethylene glycol dimethyl ether, propylene glycol methyl ether, propylene glycol propyl ether, Glycol ethers such as ethylene glycol ethyl ether and ethylene glycol butyl ether; Carbitols such as methyl carbitol, ethyl carbitol and butyl carbitol; Tate, such as ethylene glycol ethyl ether acetate, lower esters of glycols or glycol ethers, ketones alcohols such as diacetone alcohol; dimethylformamide, dimethylacetamide, substituted amides such as N- methylpyrrolidone.

  On the other hand, a second group of aqueous organic solvents that hardly dissolve the copolyester resin but can dissolve the polymer monomer mixture containing the carboxyl group-containing polymerizable monomer and the polymer relatively well. Examples include water, lower alcohols, lower carboxylic acids, and lower amines, with alcohols having 1 to 4 carbon atoms and glycols being particularly preferred.

  When the grafting reaction is carried out with a single solvent, only one of the first group of aqueous organic solvents can be selected. When using a mixed solvent, there are a case where a plurality of types are selected from only the first group of aqueous organic solvents and a case where at least one type is selected from the first group of aqueous organic solvents and at least one type is added from the second group of aqueous organic solvents.

  Graft polymerization reaction in both cases where the graft polymerization reaction solvent is a single solvent from the first group of aqueous organic solvents and when it is a mixed solvent consisting of each of the first group and the second group of aqueous organic solvents Can be performed.

  However, there are differences in the progress of the grafting reaction, the appearance and properties of the grafting reaction product and the aqueous dispersion derived therefrom, and a mixed solvent composed of each of the first group and the second group of aqueous organic solvents. Is preferred.

  In the solvent of the first group, the copolyester molecular chain is in a state where the chain having a large spread is extended, while in the mixed solvent of the first group / second group, it is in a state of being entangled in a string of small spread. It can be confirmed by measuring the viscosity of the copolyester in these solutions.

  It is effective for preventing gelation to adjust the dissolved state of the copolyester and to make it difficult for intermolecular crosslinking to occur. Coexistence of highly efficient grafting and gelation suppression is achieved in the latter mixed solvent system. The mass ratio of the mixed solvent of the first group / second group is more desirably in the range of 95/5 to 10/90, further desirably 90/10 to 20/80, most desirably 85/15 to 30/70. is there. The optimum mixing ratio is determined according to the solubility of the polyester used.

  The grafting reaction product according to the present invention is preferably neutralized with a basic compound, and can be easily dispersed in water by neutralization.

  As the basic compound, a compound that volatilizes at the time of forming a coating film or baking and curing with a curing agent is desirable, and ammonia, organic amines, and the like are preferable. Desirable compounds include, for example, triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine , 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, triethanol Mention may be made of amines.

  The basic compound has a pH value of the aqueous dispersion in the range of 5.0 to 9.0 by at least partial neutralization or complete neutralization, depending on the carboxyl group content contained in the grafting reaction product. It is desirable to use it. If a basic compound with a boiling point of 100 ° C. or lower is used, there are few residual basic compounds in the coating film after drying, adhesion of metals and inorganic deposited films, and water resistance adhesion when laminated with other materials Excellent heat and water resistance.

  In addition, when a basic compound of 100 ° C. or higher is used or the drying conditions are controlled, and the basic compound remains in the coated film after drying by 500 ppm or more, the transfer property of the printing ink is improved.

  In the aqueous dispersion produced according to the present invention, the weight average molecular weight of the polymer of the radical polymerizable monomer is preferably 500 to 50,000.

  Generally, it is difficult to control the weight average molecular weight of the polymer of the radical polymerizable monomer to be less than 500, the grafting efficiency is lowered, and there is a tendency that hydrophilic groups are not sufficiently imparted to the copolymer polyester. is there. In addition, the graft polymer of the radical polymerizable monomer forms a hydrated layer of dispersed particles. In order to obtain a stable dispersion by providing a sufficiently thick hydrated layer, The weight average molecular weight of the graft polymer is desirably 500 or more.

  The upper limit of the weight average molecular weight of the graft polymer of the radical polymerizable monomer is preferably 50,000 from the viewpoint of polymerizability in solution polymerization. In order to set the weight average molecular weight of the graft polymer of the radical polymerizable monomer within the range of 500 to 50,000, the initiator amount, the monomer dropping time, the polymerization time, the reaction solvent, the monomer composition, or as required The chain transfer agent and the polymerization inhibitor are preferably combined appropriately.

  In the present invention, a reaction product obtained by graft polymerization of a radically polymerizable monomer to a hydrophobic copolyester resin has a self-crosslinking property, and thus exhibits a high degree of solvent resistance. Although it does not crosslink at room temperature, it undergoes intermolecular reactions such as hydrogen abstraction by thermal radicals with heat during drying, and crosslinks without a crosslinking agent. For the first time, adhesion and water-resistant adhesion can be exhibited. The crosslinkability of the coating film can be evaluated by various methods, and examples thereof include a method of measuring the insoluble fraction in a chloroform solvent that dissolves both the hydrophobic copolyester resin and the radical polymer.

  Specifically, the insoluble fraction of the coating film obtained by drying at 80 ° C. or less and heat-treating at 120 ° C. for 5 minutes is preferably 50% by mass or more, more preferably 70% by mass or more. When the insoluble fraction of the coating film is less than 50% by mass, not only the adhesion and water-resistant adhesion are not sufficient, but also the frequency of causing blocking increases.

  The copolyester resin forming the coating layer B of the present invention is a copolyester polycondensate comprising at least one dicarboxylic acid component, at least one diol component, and an ester-forming component thereof as constituent units, The same kind of polyester resin as the coating layer A (hereinafter sometimes referred to as a printing layer) may be used, or a commonly used copolyester resin may be used.

  Examples of the dicarboxylic acid component that is a constituent component of the copolyester resin include (1) terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenylenedicarboxylic acid, 5-sodium sulfoisophthalic acid, and the like. (2) Aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid and sebacic acid, (3) Alicyclics such as 1,4-cyclohexanedicarboxylic acid and 1,2-cyclohexanedicarboxylic acid Mention may be made of unsaturated dicarboxylic acids such as dicarboxylic acids, (4) maleic acid, fumaric acid and tetrahydrophthalic acid. Of these, terephthalic acid and isophthalic acid are preferable, and other dicarboxylic acids may be added in other small amounts.

  Examples of the diol component that is the other component of the copolyester resin include (1) ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1, Aliphatic diols such as 6-hexanediol and polyethylene glycol, (2) alicyclic diols such as 1,4-cyclohexanedimethal, and (3) aromatic diols such as 4,4′-bis (hydroxyethyl) bisphenol A Furthermore, bis (polyoxyethylene glycol) bisphenol ether can be mentioned. Of these, ethylene glycol and diethylene glycol are most preferable, and a small amount of other diol components may be used.

  In addition to the dicarboxylic acid component, 5-sodium sulfoisophthalic acid is preferably used in the range of 1 to 10 mol% in order to impart water dispersibility to the copolyester resin. -Sulfoisophthalic acid, 4-sulfonaphthalene-2,6 dicarboxylic acid, 5- (4-sulfophenoxy) isophthalic acid and the like can be used.

  The resin component of these coating layers A and B is preferably contained in the coating layer in the range of 30 to 95% by mass. When the amount is less than 30% by mass, the film strength is insufficient, and the film easily falls off when an external force such as friction is applied. Furthermore, the particles are likely to fall off. On the other hand, when it exceeds 95% by mass, the strength as a film is improved, but the intended performance such as antistatic performance and slipperiness is hardly exhibited. Preferably it is 50-90 mass%.

The compound having a sulfonate group used in the present invention is a compound used for the purpose of imparting antistatic properties, for example, an unsaturated monomer having a sulfonate group (for example, sodium vinyl sulfonate, methallyl sulfonic acid). A polymer antistatic agent comprising one or more polymers of sodium, sodium styrenesulfonate, ammonium vinylsulfonate, potassium methacrylsulfonate, lithium styrenesulfonate, etc., and R-SO ₃ X (where R Is an alkyl group, an aryl group, or an aromatic group having an alkyl group, and X is a low molecular charge of a metal ion (for example, Li, Na, K, etc.), ammonium ion, amine ion, or phosphate ester ion) Antibacterial agent and its dimer are listed, but it has a sulfonate group with excellent heat resistance and antistatic properties. It has a function that expresses, but is not limited to the compound.

  Examples of the alkyl sulfonate include sodium pentane sulfonate, sodium octane sulfonate, lithium octane sulfonate, potassium octane sulfonate, and sodium tetradecyl sulfonate.

  Examples of the aryl sulfonate include sodium benzyl sulfonate, sodium toluyl sulfonate, and sodium naphthyl sulfonate. Furthermore, examples of the aromatic sulfonate having an alkyl group include alkyl (carbon number: 8 to 20) benzenesulfonic acid metal salts (for example, Li, K, Na salts) such as sodium dodecylbenzenesulfonate, and alkylnaphthalene. Examples include sodium sulfonate and sodium alkylphenyl ether disulfonate.

  The polymer antistatic agent comprising a polymer of an unsaturated monomer having a sulfonate group uses, for example, a styrene resin containing a sulfonate group component in the molecule such as polystyrene sulfonate. It is preferable.

  This polymer antistatic agent is characterized by the high hydrophilicity of its sulfonic acid component. Examples of the styrene resin containing a sulfonate group component in the molecule include homopolymers such as sodium salt, potassium salt, lithium salt, ammonium salt, and phosphonium salt of polystyrene sulfonic acid, acrylic acid ester, and methacrylic acid ester. Examples include a copolymer of an acrylic monomer and a styrene sulfonic acid monomer.

  The weight average molecular weight of the polystyrene sulfonate used in the present invention is 1,000 to 150,000, preferably 10,000 to 70,000. When the molecular weight is less than 1,000, it becomes difficult to obtain water-resistant adhesion of the coating film, and when it exceeds 150,000, uniform mixing with the copolymerized polyester tends to be difficult.

When the compound having a sulfonate group used in the present invention is a low molecule, the mixing ratio in each layer is preferably 0.5 to 15% by mass, particularly preferably 2 to 10% by mass. Moreover, when the compound which has a sulfonate group is a polymer, 5-50 mass% is preferable, Most preferably, it is 10-30 mass%. A mixture of the low molecular compound and the high molecular compound may be used. Further, if the surface resistivity of the coating layer containing the compound having a sulfonate group is not less than 10 ¹³ Ω / □ under the conditions of 23 ° C. and 50% RH, only the self-weight is obtained when the sheet is used. The slipperiness becomes insufficient under a low load, and the transportability such as double feeding in a high-speed printer tends to deteriorate. On the other hand, when the content of the compound having a sulfonate group is too large, the printed surface is likely to be contaminated due to set-off or particle dropout.

  Commercially available inorganic particles and / or organic particles can be used as the particles having an average particle diameter of 1 to 5 μm that can be used in the present invention. The average particle diameter is more preferably in the range of 1 to 3 μm. Examples of the inorganic particles include silica, calcium carbonate, and alumina, and examples of the organic particles include, but are not limited to, polyolefin, acrylic, styrene, urethane, polyamide, and polyester. The average particle size of the particles is taken by taking a plurality of photographs of at least 200 particles by electron microscopy, tracing the outline of the particles on an OHP film, and converting the trace image to an equivalent circle diameter with an image analyzer. To calculate.

  Moreover, content with respect to the resin component of the said particle | grain in a coating layer is 0.3-10 mass%, Preferably it is 0.7-5 mass%. When the average particle diameter is less than 1 μm or the particle content is less than 0.3% by mass, it is difficult to form appropriate irregularities on the surface of the coating layer. As a result, when it is a sheet-fed film, it is difficult for an air layer to accumulate between the films, the friction immediately after releasing the load cannot be reduced, and it becomes difficult to increase the printing speed. When the average particle diameter exceeds 5 μm, or when the particle content exceeds 10% by mass, the haze of the film increases, the transparency is deteriorated, or the particles are dropped, resulting in a print surface stain, a problem of print quality, The frequency of machine stand contamination increases.

  The polymer wax component used in the present invention is not particularly limited as long as it does not impair the transparency, and conventionally known ones can be used. For example, a polyethylene type, a polypropylene type, and a fatty acid type are mentioned. The weight average molecular weight of these wax components is preferably 1,000 to 10,000, more preferably 1,500 to 6,000. When the molecular weight is less than 1,000, oozing from the inside of the coating layer to the surface tends to cause transfer contamination to the printing surface, which may adversely affect the ink adhesion.

  When the molecular weight exceeds 10,000, the effect of improving slipperiness may be insufficient. Content with respect to the resin component of the wax component in a coating layer is 1-10 mass%, Preferably it is 2-8 mass%. When the content of the wax component in the coating layer with respect to the resin component is less than 1% by mass, the friction coefficient cannot be lowered sufficiently, and it becomes difficult to increase the printing speed. When the content of the wax component in the coating layer exceeds 10% by mass, the wax component is likely to fall off, thereby causing contamination on the printing surface and further deterioration of transparency and haze.

  In the present invention, the slipperiness of the molding polyester film in which the coating layers are formed on both sides is sufficient if, for example, the sheet feeding stability in the high-speed UV offset printing machine, which is the feature of the present invention described above, can be provided. However, the static friction coefficient and the dynamic friction coefficient when the coating layer A and the coating layer B are overlapped are preferably 0.5 or less.

  In a state where the dynamic friction coefficient exceeds 0.5, the slipperiness is insufficient, and a conveyance failure occurs when feeding with a sheet-fed printing press. Generally, the static friction coefficient shows a maximum value when the film is rubbed, and is higher than the dynamic friction coefficient. However, when the lubricant is included in at least one of the coating layers, the coefficient of friction rises gently with friction running, so that the value of the static friction coefficient becomes equal to or lower than the dynamic friction coefficient. A low coefficient of static friction makes the beginning of movement during sheeting smoother. As a result, the sheet-fed printing press can improve the printing speed.

  When producing the molding polyester film of the present invention, the method of forming the above-mentioned coating layer on both sides of the polyester base film is not limited and is arbitrary, but a method carried out by a coating method is suitable. As the step of applying the coating solution in this method, a method of coating on an unstretched film and then stretching in at least one direction, a method of coating after longitudinal stretching, a method of coating on the film surface after the orientation treatment, etc. Either method is possible. In particular, when producing a polyester base film, a so-called in-line coating method is applied in which the film is applied before the crystal orientation of the film is completed, and then stretched in at least one direction and then the crystal orientation of the polyester film is completed. This is a preferable method that can exhibit the effect of the above.

  The above-mentioned copolymerized polyester resin and the compound having a sulfonate group have a difference in hydrophilicity and are easily separated, so that the coating solution is 2 seconds immediately after applying a shear rate of 1000 (1 / second) or more immediately before coating. It is preferable to carry out by a method in which the coating is applied to the substrate within 2 seconds, followed by preliminary drying at 70 ° C. or less, humidity 50% RH, and wind speed of 10 to 20 m / second for 1 to 3 seconds and then drying at 90 ° C. or more. By coating by this method, the copolymer polyester resin and the compound having a sulfonate group are uniformly dispersed, and a good surface resistance value can be obtained.

  There are no particular limitations on the heat setting conditions after stretching after coating and drying in the case of the in-line coating method described above, but the self-crosslinking property of the polyester-based graft copolymer that is a constituent component of the coating layer A is particularly expressed. Therefore, it is preferable to employ a condition for increasing the amount of heat within a range in which the base film and the graft copolymer are not thermally deteriorated. Specifically, it is 200 ° C to 250 ° C, preferably 220 ° C to 250 ° C. However, by increasing the heat setting time, sufficient self-crosslinking property can be exhibited even at a relatively low temperature.

  As a method for providing the coating layer, a conventionally used method such as a gravure coating method, a kiss coating method, a dip method, a spray coating method, a curtain coating method, an air knife coating method, a blade coating method, or a reverse roll coating method is applied. be able to

  The thicknesses of the two coating layers are not particularly limited, but in the present invention, the final thickness after drying is preferably 0.05 to 1.0 μm, more preferably 0.07 to 0.5 μm, and particularly preferably. Is 0.09 to 0.3 μm.

  The coating liquid of the present invention may contain known additives such as surfactants, antioxidants, heat stabilizers, and organic lubricants as long as the effects of the present invention are not impaired.

  In the present invention, the slipperiness between the coating layer A and the coating layer B on the opposite side is very good as compared with a conventionally known method. This remarkable improvement in slipperiness when films are stacked in sheet form is as follows: (1) Air retention effect between films due to surface irregularities caused by particles having an average particle diameter of 1 to 10 μm contained in the coating layers on both sides (2) The effect of preventing electrostatic adhesion due to the sulfonic acid metal salt contained in the coating layer B, and (3) the reduction in the static friction coefficient due to the polymer wax component contained in the coating layer B. If these three effects are not all available, the cut film will not be smooth enough when it starts to move from a stationary state, it will have poor transportability from the state of being stacked in sheets, and it will have poor biting stability during feeding. The printing speed cannot be increased.

  A laminated film having a normal coating layer has inert particles in order to form irregularities on the film surface for the purpose of improving handling properties (e.g., slipperiness, winding property, blocking resistance) and scratch resistance. Contained. However, the laminated polyester film of the present invention preferably contains particles in the coating layer to improve transparency, and the content of particles in the base film is preferably reduced. It is particularly preferable not to contain it. “Substantially no particles” means that the content of main component atoms constituting the particles in the base film is below the detection limit of the fluorescent X-ray analysis method.

  In the laminated polyester film of the present invention, high transparency can be obtained while having a coating layer on both sides by using a base film substantially containing no particles inside. As a result, the brightness at the time of illumination with transmitted light is excellent, and the sharpness of characters and images when the printed surface is viewed through the film from the smooth surface (coating layer B / non-printed surface) side is obtained. It is done.

  Further, in the present invention, the adhesion strength with the coating layer A for commonly used UV curable printing inks and solvent-based printing inks is 1 mm square in cross-cut evaluation with a grid according to JIS-K5400. The residual ratio of the number of eyes is preferably 90% or more, more preferably 96% or more.

  If the adhesion force (remaining ratio of the number of squares) is less than 90%, ink dropout after printing occurs, leading to deterioration in appearance and transportability. In general, in offset printing, the ink thickness is 1 μm to several μm, so that ink drop does not easily occur. However, in screen printing, the ink thickness may be several μm to 10 μm or more. Therefore, it is preferable that the molding polyester film of the present invention has an adhesive force that can also be applied to screen printing ink.

  The molding polyester film of the present invention is used by applying heat, pressure, or the like to be deformed. Examples of the molding means include pressure molding, press molding, laminate molding, vacuum molding, vacuum / pressure molding, in-mold molding, drawing molding, and bending molding. The molded body molded in this way is used for molding members such as home appliance nameplates, automobile nameplates, dummy containers, building materials, decorative boards, decorative steel plates, transfer sheets, etc., but it is used as a dummy container member. Since the effects of the present invention can be suitably expressed, this is a preferred embodiment.

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

(1) Intrinsic viscosity 0.1 g of the chip sample was precisely weighed and dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane = 6/4 (mass ratio), and measured at 30 ° C. using an Ostwald viscometer. In addition, the measurement was performed 3 times and the average value was obtained.

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

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

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

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

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

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

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

(7) Formability After printing on the film, it was contact-heated with a hot plate at 140 ° C for 4 seconds, and then press-molded at a mold temperature of 70 ° C and a holding time of 5 seconds. The shape of the mold was a cup shape, the opening portion had a diameter of 50 mm, the bottom portion had a diameter of 40 mm, the depth was 20 mm, and all corners were rounded with a radius of 1 mm. After press molding, printing misalignment was measured, and the molding state was visually observed, and ranked according to the following criteria. In addition, (double-circle) and (circle) were set as the pass, and x was set as the failure.

A: (i) Molded product is not torn, (ii) Corner radius of curvature is 2 mm or less, printing deviation is 0.1 mm or less, and (iii) No appearance defect corresponding to x: (I) The molded product is not torn, (ii) The corner radius of curvature is more than 2mm and 3mm or less, or the printing deviation is more than 0.1mm and 0.2mm or less. There is no appearance defect and there is no problem in practical use ×: The molded product is torn, or even if it is not torn, it falls under any of the following items (i) to (iv)
(I) Corner radius of curvature exceeds 3mm
(ii) A large bag with a bad appearance
(iii) The film is whitened and the transparency is lowered
(iv) Print misalignment exceeding 0.2 mm

(8) Static friction coefficient μs and dynamic friction coefficient μd
Based on JIS C2151, it evaluated on condition of the following.
Test piece for flat plate: 130 mm in width and 250 mm in length, using non-printing surface side Test piece for warping: 120 mm in width, using 120 mm in length and printing surface side Measurement atmosphere: 23 ° C., 50% RH
Sled mass: 200 gf
Test speed: 150mm / min

(9) Surface resistivity The surface resistivity in the atmosphere of 23 ° C. and 50% RH using a surface resistance meter (manufactured by Mitsubishi Yuka Co., Ltd., HIRESUTA MCP HT-260) on the printed surface of the sample film and the opposite surface. (Ω / □) was measured under the following conditions.
Applied voltage: 500V
Measurement time: 10 seconds Probe used: Type HRS

(10) Ink Adhesion Strength In accordance with the cross-cut evaluation method described in 8.5.1 of JIS-K5400, the ink adhesion strength of the printed surface of the film (coating layer A in the present invention) was evaluated. Specifically, after printing the following ink on the printing surface of the film, using a crosscut guide, 100 pieces of 1 mm squares were created on the printing surface with a cutter blade, and then an adhesive tape (product name cellophane tape, manufactured by Nichiban Co., Ltd.). ) Was affixed to the printed surface and completely adhered so that no air remained. Next, after the adhesive tape was peeled off vertically, the remaining number of squares on the printed surface was evaluated as adhesion (remaining number / 100).

  Adhesion strength with UV curable ink is UV curable ink (manufactured by Toka Dye Co., Ltd., Best Cure 161), and the surface of the coating layer (application layer A of the present invention) is irradiated with 100 mJ of UV after printing with an RI tester. And evaluated according to the above method. Also, using another UV curable ink (Seiko Advance Co., Ltd., UVA), the surface of the coating layer (the coating layer A of the present invention) was irradiated with 500 mJ of UV after # 300 screen printing, and the same procedure was followed. Evaluated.

  The adhesive strength with the solvent type ink is solvent type ink (manufactured by Toyo Ink Co., Ltd., TSP-400G), the film is coated on the coating layer surface (coating layer A of the present invention) with an RI tester and left to dry for 24 hours. Evaluation was made according to the method. Also, using other solvent-based ink (Tetron, manufactured by Jujo Ink Co., Ltd.), the coating layer surface (coating layer A of the present invention) was left to dry for 24 hours after screen printing of # 250, and similarly evaluated according to the above method. did.

(11) Feeding stability Using a sheet-fed offset printing machine (Heidelberg, Speedmaster, 8-color printing machine), stacking sheets of Kikuzen size (636 x 939 mm) size sheets at low printing speed The sheet feeding stability was evaluated when feeding and printing at (4,000 sheets / hour) and at high speed (8,000 sheets / hour). The case where the paper could be fed stably was marked with ◯, and the case where trouble such as double feeding or jamming occurred during paper feeding was marked with ×.

(12) Print quality The print appearance of the print sample used in the feed stability evaluation was visually determined. At this time, the appearance was visually judged through the film from the back side, not from the printed surface. The case where the clear feeling and the printability both satisfy the following criteria was evaluated as ◯, and the case where none of them satisfied was evaluated as x.
(Clear feeling)
The printed design looks clear without being blocked by the base film or coating layer (printability)
Color unevenness and missing due to poor transfer of printing ink

Example 1
(Preparation of hydrophobic copolyester resin)
In a stainless steel autoclave equipped with a stirrer, a thermometer and a partial reflux condenser, 218 parts by mass of dimethyl terephthalate, 194 parts by mass of dimethyl isophthalate, 488 parts by mass of ethylene glycol, 200 parts by mass of neopentyl glycol and tetra-N-butyl titanate 0.5 parts by mass was charged, and a transesterification reaction was performed from 160 ° C. to 220 ° C. over 4 hours. Next, 13 parts by mass of fumaric acid and 51 parts by mass of sebacic acid were added, and the temperature was raised from 200 ° C. to 220 ° C. over 1 hour to carry out an esterification reaction. Next, the temperature was raised to 255 ° C., and the reaction system was gradually depressurized, and then reacted for 1 hour 30 minutes under a reduced pressure of 0.22 mmHg to obtain a hydrophobic copolyester resin. The obtained hydrophobic copolyester was light yellow and transparent.

(Preparation of water-dispersed polyester-based graft copolymer)
In a reactor equipped with a stirrer, thermometer, refluxing device and quantitative dropping device, 75 parts by mass of hydrophobic copolymer polyester, 56 parts by mass of methyl ethyl ketone and 19 parts by mass of isopropyl alcohol are heated and stirred at 65 ° C. Dissolved. After the resin was completely dissolved, 15 parts by mass of maleic anhydride was added to the polyester solution. Subsequently, a solution prepared by dissolving 10 parts by mass of styrene and 1.5 parts by mass of azobisdimethylvaleronitrile in 12 parts by mass of methyl ethyl ketone was dropped into the polyester solution at 0.1 ml / min, and stirring was further continued for 2 hours. After sampling for analysis from the reaction solution, 5 parts by mass of methanol was added. Next, 300 parts by mass of ion-exchanged water and 15 parts by mass of triethylamine were added to the reaction solution and stirred for 1.5 hours. Thereafter, the reactor internal temperature was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol, and excess triethylamine were distilled off to obtain a water-dispersed polyester graft copolymer. The obtained polyester-based graft copolymer was light yellow and transparent, and the glass transition temperature was 40 ° C.

(Preparation of coating solution a for forming coating layer A)
A polyester graft copolymer dispersed in water so that the total solid concentration is 5% by mass in a mixed solvent of ion-exchanged water and isopropyl alcohol (mass ratio: 60/40), and the average particle size as particles 2.2μm styrene-benzoguanamine-based spherical organic particles (made by Nippon Shokubai Co., Ltd.) and colloidal silica having an average particle size of 0.02μm (made by Catalytic Chemical Industry) are mixed so that the mass ratio as a solid content is 50/1/3. The coating solution a was prepared.

(Preparation of coating solution b for forming coating layer B)
In a mixed solvent of ion-exchanged water and isopropyl alcohol (mass ratio: 60/40), a water-dispersible polyester-based copolymer (manufactured by Toyobo Co., Ltd., Bironal) so that the total solid content concentration is 5% by mass. MD-16), sodium dodecyl diphenyl oxide disulfonate (manufactured by Matsumoto Yushi Co., Ltd., an anionic antistatic agent) as a metal salt of sulfonic acid, polyethylene emulsion wax (manufactured by Toho Chemical Industry) as a polymer wax agent, and average as particles Styrene-benzoguanamine-based spherical organic particles (manufactured by Nippon Shokubai Co., Ltd.) having a particle size of 2.2 μm and colloidal silica (manufactured by Nissan Chemical Industries) having an average particle size of 0.04 μm in a mass ratio of 50 / 2.5 / 2.5, respectively. /0.5/5 was mixed to prepare coating solution b.

(Preparation of laminated polyester film)
Copolymer polyester chip having an intrinsic viscosity of 0.69 dl / g, comprising 100 mol% of terephthalic acid units as aromatic dicarboxylic acid components, 40 mol% of ethylene glycol units and 60 mol% of neopentyl glycol units as diol components. After drying (A) and the polyethylene terephthalate chip (B) having an intrinsic viscosity of 0.69 dl / g, they were mixed so as to have a mass ratio of 25:75. Subsequently, these chip mixtures were melt-extruded from the slit of the T die at 280 ° C. with an extruder, rapidly cooled and solidified on a chill roll having a surface temperature of 40 ° C., and at the same time, the amorphous mixture was adhered to the chill roll using an electrostatic application method. A stretched sheet was obtained.

The obtained unstretched sheet was stretched 3.5 times at 92 ° C. in the longitudinal direction between the heating roll and the cooling roll. Next, coating liquid a for forming coating layer A was applied to one side of the uniaxially stretched film, and coating liquid b for forming coating layer B was applied to the other side by a reverse kiss coating method. In addition, each coating liquid applied a shear rate of 1000 (1 / second) or more between the roll gaps, applied to the substrate film within 2 seconds, and in an environment of 65 ° C., 60% RH, and wind speed of 15 m / second, It was dried with hot air for 2 seconds, and further dried with hot air for 3 seconds in an environment of 130 ° C. and a wind speed of 20 m / second to remove moisture. Next, the uniaxially stretched film after coating is guided to a tenter, preheated at 100 ° C. for 15 seconds, the first half of the transverse stretching is stretched 3.6 times at 115 ° C. and the latter half is 95 ° C., and the relaxation is 7% in the transverse direction. Then, heat treatment was performed at 205 ° C. to obtain a biaxially stretched polyester film for molding having a coating layer A on one side and a coating layer B on the other side, having a thickness of 188 μm. The coating amount of the coating layer A and the coating layer B was 1 g / m ² .

Comparative Example 1
The aromatic dicarboxylic acid component is 100 mol% terephthalic acid unit, the diol component is 85 mol% ethylene glycol unit and 15 mol% neopentylglycol unit, and the average particle size (electron microscopy, equivalent circle diameter) is 1. A copolyester chip (C) containing 400 ppm of 0.5 μm amorphous silica and having an intrinsic viscosity of 0.69 dl / g was pre-crystallized and then dried. This chip (C) was melt-extruded from the slit of the T die at 280 ° C. by an extruder, rapidly cooled and solidified on a chill roll having a surface temperature of 40 ° C., and at the same time, amorphous unstretched while closely contacting the chill roll using an electrostatic application method. A sheet was obtained.

  The obtained unstretched sheet was stretched 3.5 times at 92 ° C. in the longitudinal direction between the heating roll and the cooling roll. Subsequently, application | coating of the coating liquid a and B which forms the coating layer A and the coating layer B to a uniaxially-oriented polyester film was stopped, and the uniaxially stretched film was guide | induced to the tenter as it was. Then, preheat at 100 ° C. for 15 seconds, stretch the first half of the transverse stretching at 115 ° C. and stretch the latter half at 95 ° C. by 3.6 times, and heat-treat at 205 ° C. while relaxing 7% in the transverse direction. A biaxially stretched polyester film having a thickness of 188 μm and having no layer was obtained.

Comparative Example 2
A polyethylene terephthalate chip (B) having an intrinsic viscosity of 0.69 dl / g was pre-crystallized and then dried. Next, this chip (B) was melt-extruded from the slit of the T die at 280 ° C. by an extruder and rapidly cooled and solidified on a chill roll having a surface temperature of 40 ° C. An unstretched sheet was obtained.

The obtained unstretched sheet was stretched 3.7 times at 97 ° C. in the longitudinal direction between the heating roll and the cooling roll. Next, coating liquid a for forming coating layer A was applied to one side of the uniaxially stretched film, and coating liquid b for forming coating layer B was applied to the other side by a reverse kiss coating method. In addition, each coating liquid applied a shear rate of 1000 (1 / second) or more between the roll gaps, applied to the substrate film within 2 seconds, and in an environment of 65 ° C., 60% RH, and wind speed of 15 m / second, It was dried for 2 seconds and further dried for 3 seconds in an environment of 130 ° C. and a wind speed of 20 m / second to remove moisture. Next, the uniaxially stretched film after coating is guided to a tenter, preheated at 100 ° C. for 15 seconds, the first half of the transverse stretching is stretched 4.0 times at 120 ° C. and the latter half is 120 ° C., and 10% relaxation in the transverse direction. A biaxially stretched polyester film having a thickness of 188 μm and having a coating layer A on one side and a coating layer B on the other side was obtained. The coating amount of the coating layer A and the coating layer B was 1 g / m ² .

Comparative Example 3
In Example 1, the coating layer was formed on either side in the same manner as in Example 1, except that the coating liquid A and the coating liquid b for forming the coating layer A and the coating layer B on the uniaxially oriented polyester film were stopped. A biaxially stretched polyester film having a thickness of 188 μm was obtained.

Comparative Example 4
In Example 1, except that the coating layer A was not provided, a biaxially stretched polyester film having a thickness of 188 μm having only the coating layer B on one side as a coating layer was obtained in the same manner as in Example 1. The coating amount of the coating layer B was 1 g / m ² .

Comparative Example 5
In Example 1, except that the coating layer B was not provided, a biaxially stretched polyester film having a thickness of 188 μm having only the coating layer A on one side as a coating layer was obtained in the same manner as in Example 1. The coating amount of the coating layer A was 1 g / m ² .

Example 2
Copolymer polyester chip having an intrinsic viscosity of 0.75 dl / g, comprising 100 mol% of terephthalic acid unit as the aromatic dicarboxylic acid component, 70 mol% of ethylene glycol unit and 30 mol% of cyclohexanedimethanol unit as the diol component D) and a polyethylene terephthalate chip (B) having an intrinsic viscosity of 0.69 dl / g were mixed at a mass ratio of 70:30 and dried. Subsequently, these chip mixtures were melt-extruded from the slit of the T die at 280 ° C. with an extruder, rapidly cooled and solidified on a chill roll having a surface temperature of 40 ° C., and at the same time, the amorphous mixture was adhered to the chill roll using an electrostatic application method. A stretched sheet was obtained.

The obtained unstretched sheet was stretched 3.0 times at 85 ° C. in the longitudinal direction between the heating roll and the cooling roll. Next, coating liquid a for forming coating layer A was applied to one side of the uniaxially stretched film, and coating liquid b for forming coating layer B was applied to the other side by a reverse kiss coating method. In addition, each coating liquid applied a shear rate of 1000 (1 / second) or more between the roll gaps, applied to the substrate film within 2 seconds, and in an environment of 65 ° C., 60% RH, and wind speed of 15 m / second, It was dried for 2 seconds and further dried for 3 seconds in an environment of 130 ° C. and a wind speed of 20 m / second to remove moisture. Next, the uniaxially stretched film after coating is guided to a tenter, preheated at 105 ° C. for 15 seconds, the first half of the transverse stretching is stretched 3.6 times at 125 ° C. and the latter half is 98 ° C., and the relaxation is 7% in the transverse direction. Then, heat treatment was performed at 205 ° C. to obtain a biaxially stretched polyester film for molding having a coating layer A on one side and a coating layer B on the other side, having a thickness of 188 μm. The coating amount of the coating layer A and the coating layer B was 1 g / m ² .

Example 3
In Example 1, after the copolymer polyester chip (A) having an intrinsic viscosity of 0.69 dl / g and the polyethylene terephthalate chip (B) having an intrinsic viscosity of 0.69 dl / g were sufficiently dried, A biaxially stretched polyester film for molding having a coating layer A on one side and a coating layer B on the other side, having a thickness of 188 μm, in the same manner as in Example 1 except that the mass ratio was 33:67. Got. The coating amount of the coating layer A and the coating layer B was 1 g / m ² .

  Table 1 shows the raw material polymers used in Examples 1 to 3 and Comparative Examples 1 to 5, compositions of the coating layers, and film forming conditions, and Table 2 shows the characteristics of the obtained films.

Example 4
The film obtained in Examples 1 to 3 is a sheet of offset size printing machine (manufactured by Heidelberg, Speedmaster, 8-color printing machine) using UV curable ink and having a size of Kikuzen (636 × 939 mm) size. The leaf films were stacked, fed at a printing speed of 8,000 sheets / hour, and printed on the coating layer A surface. The printing operability and the printing characteristics of the printed product were good. The obtained printed polyester film for molding is heated at 130 ° C. for 5 seconds and then press-molded at a mold temperature of 80 ° C. and a holding time of 5 seconds to form a constricted dummy beverage bottle (actual bottle) ) Was created. Molding operability, paper feeding stability, and printing quality of the obtained dummy beverage bottle were good.

Comparative Example 6
Printing and molding were performed in the same manner as in Example 4 using the films of Comparative Examples 1 to 5. When the films of Comparative Examples 1 and 3 were used, the printing quality and paper feed stability were poor. Further, when the film of Comparative Example 2 was used, the moldability was poor, when the film of Comparative Example 4 was used, the paper feeding stability was poor, and when the film of Comparative Example 5 was used, the print quality was poor. . Further, when the films of Comparative Examples 1 and 2 were used, the transparency was poor.

  The polyester film for molding of the present invention is particularly excellent in moldability at low temperatures and elasticity and shape stability (thickness unevenness, heat shrinkage characteristics) when used in a room temperature atmosphere as a molded product. It is suitable as a film for various moldings such as embossing and vacuum forming. Furthermore, by using the molding polyester film as a base material and laminating the coating layer A on one side of the base material and the coating layer B on the other side, in addition to the easy moldability that is a feature of the base material, multicolor printing The high-speed UV offset printing machine is excellent in paper feed stability, ink adhesion, and the like, and can perform high-quality printing at high speed. Therefore, it is most suitable as a member for a dummy container. Furthermore, it can utilize also for the member for nameplates of a household appliance or a motor vehicle, or the member for building materials.

Claims (7)

For molding, in which a polyester film containing substantially no particles is used as a base material, and a coating layer A containing an adhesive modifying resin is laminated on one side of the base material and a coating layer B containing particles and wax is laminated on the other side A polyester film,
The base material has a melting point (Tm) of 220 ° C. or higher including a copolymerized polyester synthesized from an aromatic dicarboxylic acid component and ethylene glycol and a glycol component containing a branched aliphatic glycol and / or an alicyclic glycol. Made of polyester film below 245 ° C,
The branched aliphatic glycol is neopentyl glycol;
The alicyclic glycol is 1,4-cyclohexanedimethanol;
And the ratio (H / d) of haze (H) to thickness (d) is more than 0 and 0.01% / μm or less,
A polyester film for molding, wherein the stress at 100% elongation in the longitudinal direction and the width direction is 10 MPa or more and less than 180 MPa at 25 ° C. and 1 MPa or more and 100 MPa or less at 100 ° C.
The polyester film for molding according to claim 1 , wherein the film has a thickness unevenness of 5.5% or less. The polyester film for molding according to claim 1 or 2 , wherein the film has a heat shrinkage rate of not more than 6.0% in a longitudinal direction and a width direction at 150 ° C. The coating layer A is (a) a polyester-based graft copolymer obtained by grafting an acid anhydride having at least one double bond to a hydrophobic copolymerized polyester resin, and (b) an average particle size of 1.0 to It consists of a composition containing a 5.0 micrometer particle | grain, The polyester film for shaping | molding in any one of Claims 1-3 characterized by the above-mentioned. The coating layer B comprises (c) a copolyester resin, (d) a compound having a sulfonate group, (e) particles having an average particle diameter of 1.0 to 5.0 μm, and (f) a polymer wax. It consists of a composition containing, The polyester film for shaping | molding in any one of Claims 1-4 characterized by the above-mentioned. The polyester film for molding according to any one of claims 1 to 5 , wherein a static friction coefficient and a dynamic friction coefficient when the coating layer A and the coating layer B are superposed are both 0.5 or less. The dummy container obtained from molding polyester film according to any one of claims 1-6.