JP2004090417A - Laminated polyester film, laminated polyester film for molding, and molding component using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated polyester film suitable for molding use which is excellent in formability in hot molding, excellent in form stability and transparency when used under ordinary temperature atmosphere as a molding body and excellent in adhesion properties to a printed layer. <P>SOLUTION: The laminated polyester film is constituted by providing an adhesive property modified layer on at least one side of a polyester substrate film containing an aromatic dicarboxylic constituent and a polymeric polyester comprising a glycol constituent containing ethylene glycol, branched aliphatic glycol and/or aliphatic glycol. Then, for the laminated film, a ratio(H/d) of haze H(%)/thickness d(μm) is ≤ 0.020 and a stress in 100% elongation in a lengthwise direction and a widthwise direction of the film is 180-1,000 MPa at 25°C and 1-100 MPa at 100°C. <P>COPYRIGHT: (C)2004,JPO

Description

【０１４５】
実施例６
実施例１で得られた積層ポリエステルフィルムを、金型温度１００℃でプレス成形を行い、押し込み深さ２．０ｍｍのスイッチ用銘板を作成した。得られた銘板の外観は良好であった。
【０１４６】
【発明の効果】
本発明の積層ポリエステルフィルムでは，ヘイズおよびフィルムの長手方向及び幅方向の１００％伸張時応力を制御したフィルムに塗布層を設けることにより，加工性，印刷性，透明性に優れたフィルムを得ることができたものである．
【０１４７】
【発明の効果】
本発明の積層ポリエステルフィルムは、フィルムの長手方向及び幅方向の１００％伸張時応力を２５℃と１００℃で独立して制御しているため、加熱時の成形性と、成形体としての使用時の形態安定性（弾性、強度、熱収縮特性、厚み斑）に優れている。また、インモールド成形性、エンボス成形性、真空成形性を有しているため、成形用ポリエステルフィルムとして特に好適である。さらに、接着改質層を基材フィルムに積層することにより、成形品の意匠性を高めるために接着改質層面に印刷層を設けた際の印刷性（印刷鮮明性、印刷ずれ）に優れている。そのため、前記成形用積層ポリエステルフィルムは、家電、自動車用銘板用及び建材用部材などとして好適な成形部材である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a laminated polyester film which is excellent in moldability, printability, transparency, and form stability (elasticity, strength, heat shrinkage properties, thickness unevenness), and is suitable as a member for nameplates or building materials of home appliances and automobiles. And a molded member using the same.
[0002]
[Prior art]
Conventionally, a polyvinyl chloride film has been typically used as a processing sheet, and has been preferably used in view of workability and the like. On the other hand, the film has problems such as generation of toxic gas when the film is burned by a fire or the like, bleeding out of a plasticizer, and the like, and a new material has been demanded in recent years due to needs for environmental resistance.
[0003]
Conventionally, by using a copolymer polyester containing a long-chain linear aliphatic dicarboxylic acid component having 3 or more carbon atoms and / or a long-chain linear aliphatic glycol component as a film raw material, moldability is improved. There are many improved technical disclosures. However, the drawback that the polyester resin is softened by these copolymerization components and has poor morphological stability (elasticity, strength, heat shrinkage properties, thickness unevenness, etc.) not only at the time of molding but also when actually used as a molded article. have. If the copolymer composition ratio of the above components is reduced in order to enhance the form stability, the moldability decreases, and it is difficult to achieve both the moldability and the strength and elasticity.
[0004]
For example, a polyester film comprising a polyester containing neopentyl glycol as a copolymer component as the copolymerized polyester is described in JP-A-1-252658 and JP-A-1-45699. Since the copolyester films described in these prior arts have a thickness of 50 μm or less, film formation is relatively easy.
[0005]
However, if the thickness exceeds 50 μm, the molecular orientation tends to be insufficiently controlled from the viewpoint of the stress reduction and crystallinity at the time of stretching, which are inherently possessed by the copolyester. (Elasticity, strength, heat shrinkage properties, thickness unevenness) may be insufficient. Therefore, there has been a demand for a polyester film having excellent shape stability (elasticity, strength, heat shrinkage properties, thickness unevenness) when using a molded article in a normal temperature atmosphere while maintaining the moldability.
[0006]
In addition, in order to enhance the design, the molded body is often printed on the film surface before the film is molded. However, the conventional technology has a problem that printability and heat stability of a print layer are insufficient.
[0007]
Further, since the printing layer is often applied to the back side of the molded film, it is required that the film has high transparency from the viewpoint of print clarity. However, since the conventional molded film has low transparency, there are problems that the printed appearance is deteriorated and that backlight light is hardly transmitted and visibility is deteriorated.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to solve the above-mentioned problems of the prior art, to provide excellent moldability at the time of heat molding, and to use the molded article under normal temperature atmosphere in form stability (elasticity, strength, heat shrinkage properties, Provided is a laminated polyester film having excellent thickness unevenness) and transparency, and having excellent adhesion to a printed layer, particularly a molded polyester film suitable for molding applications having excellent print clarity, and a molded member using the same. Is to do.
[0009]
[Means for Solving the Problems]
That is, the present invention provides at least one surface of a polyester base film containing a copolyester composed of an aromatic dicarboxylic acid component and a glycol component containing ethylene glycol, a branched aliphatic glycol and / or an alicyclic glycol. A laminated polyester film provided with an adhesion modifying layer, wherein the ratio (H / d) of the haze H (%) to the thickness d (μm) is 0.020 or less; Is a laminated polyester film characterized in that the stress at 100% elongation in the longitudinal direction and the width direction is 180 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C.
[0010]
Further, the present invention is a laminated polyester film for molding, wherein the laminated polyester film is used as a molded member. Further, the present invention is a molded member using the laminated polyester film for molding.
[0011]
[Action]
The laminated polyester film of the present invention contains, in a base film, a copolymer polyester composed of an aromatic dicarboxylic acid component and a glycol component containing ethylene glycol and a branched aliphatic glycol and / or an alicyclic glycol. The branched aliphatic glycol and / or alicyclic glycol has a side chain or a cyclic structure that suppresses motility such as free rotation of a molecule. The melting point (Tm) can be lowered and the breaking elongation can be increased without lowering the transition temperature (Tg).
[0012]
The laminated polyester film of the present invention using such a copolymerized polyester as a raw material of a base film has excellent moldability under a high-temperature atmosphere during molding, and has excellent morphological stability under a normal-temperature atmosphere used as a molded article ( It is also excellent in elasticity, strength, heat shrinkage properties and thickness unevenness), and is a laminated polyester film particularly suitable for molding applications.
[0013]
The above characteristics can be expressed by physical properties such that the stress at 100% elongation in the longitudinal direction and the width direction is 180 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C.
[0014]
The stress at the time of 100% elongation in a 25 ° C. atmosphere in the longitudinal direction and the width direction of the laminated film is from the viewpoint of achieving both form stability (elasticity, strength, thickness unevenness, heat shrinkage at 150 ° C.) and moldability. It is important that the pressure be 180 to 1000 MPa.
[0015]
The lower limit value of the stress at 100% elongation at 25 ° C. is preferably 210 MPa, particularly preferably 220 MPa, from the viewpoint of elasticity and uneven thickness in a normal temperature atmosphere when using a molded body.
[0016]
On the other hand, in the case of a highly elastic film having a stress at 100% elongation in an atmosphere of 25 ° C. exceeding 1000 MPa, the moldability at the time of heat molding tends to deteriorate.
[0017]
From the viewpoint of moldability, it is important that the stress at 100% elongation in a 100 ° C. atmosphere in the longitudinal direction and the width direction of the laminated film is 1 to 100 MPa.
[0018]
The lower limit of the stress at 100% elongation under 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 a 100 ° C. atmosphere is a desirable direction from the viewpoint of moldability. However, when the stress at 100% elongation in an atmosphere at 100 ° C. becomes small, the stress at 100% elongation at 25 ° C. also becomes small, and the elasticity and thickness unevenness under an atmosphere at normal temperature tend to deteriorate.
[0019]
On the other hand, the stress at 100% elongation at 100 ° C. is preferably 90 MPa, and particularly preferably 80 MPa, from the viewpoint of moldability during heat molding.
[0020]
Further, from the viewpoint of moldability, the elongation at break at 100 ° C. is preferably 150% or more, more preferably 170% or more, and particularly preferably 200% or more.
[0021]
Further, from the viewpoint of form 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, and particularly preferably. 170% or more.
[0022]
Further, from the viewpoint of the balance of the formability of the laminated film in the longitudinal and transverse directions, the stress ratio at 100% elongation at 100 ° C. in the longitudinal direction and the width direction (higher numerical value / lower numerical value) is 1. It is preferably from 0.5 to 1.60. The upper limit is particularly preferably 1.40. When the upper limit exceeds 1.60, dimensional stability at the time of molding, printing deviation, and the like are liable to be deteriorated.
[0023]
In the present invention, as the temporal stability of the workability, the change rate of the stress at 100% elongation in the longitudinal direction and the width direction at 100 ° C. ((one month after the film formation-immediately after the film formation) × 100 / immediately after the film formation). However, each is preferably ± 20% or less. It is more preferably ± 10% or less, particularly preferably ± 5% or less.
[0024]
Further, it is desirable that the ratio (H / d) of the haze H (%) to the thickness d (μm) of the laminated film is 0.020 or less from the viewpoint of transparency and print clarity. The H / d is more preferably more than 0 and 0.017 or less, particularly preferably more than 0 and 0.015 or less.
[0025]
The lower limit of the H / d is preferably as close to zero as possible. However, if the minimum necessary unevenness is not formed on the film surface, handling properties such as slipperiness and winding property will be deteriorated, and the film surface will be scratched or produced. In some cases, the lower limit of the H / d is preferably 0.001, and particularly preferably 0.005. In the case of a translucent nameplate using a backlight or the like, a high degree of transparency is required for the film.
[0026]
In the laminated polyester film of the present invention, the thickness of the base film is preferably 50 to 500 μm from the viewpoints of moldability, stiffness, protection of a printed layer provided on the back surface of the molded film, and design. The lower limit of the thickness of the base film is preferably 60 μm, and 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.
[0027]
Moreover, it is preferable that unevenness in thickness of the laminated polyester film is 5.5% or less. If the thickness unevenness exceeds 5.5%, printability and dimensional stability tend to deteriorate. The thickness unevenness is desirably small, but it is technically difficult to reduce the thickness unevenness to 0.5% or less, and there is no significant difference in practical quality. Therefore, the lower limit of the thickness unevenness is 0%. It may be 0.5% or more.
[0028]
Furthermore, the heat shrinkage in the longitudinal direction and the width direction at 150 ° C. of the laminated polyester film of 3.0% or less is that the printing misalignment after the printing layer is provided on the adhesion modified resin layer side of the laminated polyester film. It is preferable from the viewpoint of reduction.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail.
[0030]
The polyester in the present invention means a general term for a high molecular weight substance constituted by an ester bond.
[0031]
In the laminated polyester film of the present invention, a copolymer polyester composed of an aromatic dicarboxylic acid component and a glycol component containing ethylene glycol and a branched aliphatic glycol and / or an alicyclic glycol is used as a base film raw material. Used as a part or 100%.
[0032]
In the copolymerized polyester, the aromatic dicarboxylic acid component is mainly composed of terephthalic acid or an ester-forming derivative thereof, and the amount of the terephthalic acid component relative to all dicarboxylic acid components is 70 mol% or more, preferably 85 mol% or more, and particularly preferably. Is 95 mol% or more, particularly preferably 100 mol%.
[0033]
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 tricyclodecanedimethylol.
[0034]
Among these, neopentyl glycol and 1,4-cyclohexane dimethanol are particularly preferable, and the stress at the time of 100% elongation in the longitudinal direction and the width direction of the film specified in the present invention is 180 to 1000 MPa at 25 ° C. and 100 to 100 ° C. It is effective for satisfying 1 to 100 MPa. Further, it is preferable not only because it has excellent moldability and transparency, but also because it has excellent heat resistance and improves the adhesion to the adhesive property-modifying layer.
[0035]
Further, if necessary, one or more of the following dicarboxylic acid components and / or glycol components may be used as a copolymer component in the copolymerized polyester.
[0036]
Other dicarboxylic acid components that can be used in combination with terephthalic acid or its ester-forming derivative include (1) isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid Aromatic dicarboxylic acids such as acid, diphenyl sulfone dicarboxylic acid, 5-sodium sulfoisophthalic acid, and phthalic acid or ester-forming derivatives thereof, (2) oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, and maleic acid Dicarboxylic acids such as fumaric acid and glutaric acid or ester-forming derivatives thereof, (3) alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and ester-forming derivatives thereof, (4) p-oxybenzoic acid, Oxycarboxylic acids such as oxycaproic acid or esters thereof Forming derivatives and the like.
[0037]
On the other hand, other glycol components that can be used in combination with ethylene glycol and the branched aliphatic glycol and / or alicyclic glycol include, for example, 1,3-propanediol, 1,4-butanediol, pentanediol, and hexane. Examples thereof 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.
[0038]
Further, if necessary, a polyfunctional compound such as trimellitic acid, trimesic acid, and trimethylolpropane can be copolymerized with the copolymerized polyester.
[0039]
As the catalyst used for producing the copolymerized polyester, for example, an alkaline earth metal compound, a manganese compound, a cobalt compound, an aluminum compound, an antimony compound, a titanium compound, a titanium / silicon composite oxide, a germanium compound and the like can be used. . Among these, titanium compounds, antimony compounds and germanium compounds are preferred from the viewpoint of catalytic activity.
[0040]
When producing the copolymerized polyester, it is preferable to add a phosphorus compound as a heat stabilizer. As the phosphorus compound, for example, phosphoric acid, phosphorous acid and the like are preferable.
[0041]
The copolymerized polyester preferably has an intrinsic viscosity of at least 0.50 dl / g, more preferably at least 0.55 dl / g, particularly preferably at least 0.55 dl / g, from the viewpoint of moldability, adhesiveness and film-forming stability. It is 60 dl / g or more. If the intrinsic viscosity is less than 0.50 dl / g, the moldability tends to decrease.
[0042]
The base film in the laminated polyester film of the present invention may use the copolymerized polyester as it is as a film raw material, or blend the copolymerized polyester with a large amount of the copolymerized component with the homopolyester to adjust the amount of the copolymerized component. It does not matter.
[0043]
It is preferable from the viewpoint of moldability that two or more of the above-mentioned copolymerized polyesters are blended and used as a raw material of the base film in the laminated polyester film of the present invention. Among them, a mixed polymer obtained by blending polyethylene terephthalate with polyneopentene terephthalate and / or polycyclohexane dimethylene terephthalate is particularly preferred from the viewpoint of flexibility and moldability.
[0044]
The melting point of the polyester base film is preferably 230 to 270 ° C. from the viewpoint of heat resistance and moldability. 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 lower limit of the melting point is more preferably 235 ° C, particularly preferably 240 ° C. When the melting point is lower than 230 ° C., the heat resistance tends to deteriorate. Therefore, when exposed to high temperatures during molding or use of the molded body, a problem may occur.
[0045]
Further, it is preferable to form irregularities on the film surface in order to improve the handling properties such as the slipperiness and winding property of the film. As a method of forming irregularities on the film surface, a method of incorporating particles into the film is generally used. However, the particles contained in the film generally have a different refractive index from that of the polyester, which causes a reduction in the transparency of the film.
[0046]
Therefore, in order to increase the transparency of the film while maintaining the handleability of the film, it is effective to include the particles only in the adhesion modification layer without substantially containing the particles in the base film. This is one of suitable means for controlling the ratio (H / d) of the haze H (%) to the thickness d (μm) of the laminated film to 0.020 or less.
[0047]
The term “substantially not containing particles in the base film” as described above means, for example, in the case of inorganic particles, the content that is below the detection limit when the inorganic element is quantified by fluorescent X-ray analysis. . This is because even if the particles are not intentionally added to the adhesive property modification layer, contamination components and the like derived from a foreign substance may be mixed.
[0048]
Examples of the particles to be contained in the adhesion modifying layer include inorganic particles and / or organic particles having an average particle diameter of 0.01 to 10 μm. These inorganic particles and / or organic particles may be used in combination of two or more as necessary.
[0049]
When particles having an average particle diameter of more than 10 μm are contained in the adhesive property-modifying layer, defects tend to occur in the film, and the design property tends to deteriorate. On the other hand, when the particles have an average particle diameter of less than 0.01 μm, the handling properties such as the slipperiness and winding property of the film tend to decrease.
[0050]
Examples of the inorganic particles include wet-process silica, dry-process silica, colloidal silica, glass filler, titanium oxide, alumina, aluminum silicate, mica, kaolin, clay, zeolite, alumina-silica composite oxide particles, hydroxyapatite, and carbonate. Calcium, calcium phosphate, barium sulfate, and the like.
[0051]
Examples of the organic particles include particles containing styrene, silicone, acrylic acid, methacrylic acid, polyester, divinylbenzene, and the like as constituent components.
[0052]
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.
[0053]
Furthermore, it is preferable that the particle content in the adhesive property modification layer is in the range of 0.01 to 25% by mass. When the content is less than 0.01% by mass, the handling properties are liable to be lowered, for example, the slipperiness of the film is deteriorated or the winding becomes difficult. On the other hand, if it exceeds 25% by mass, transparency and applicability tend to deteriorate.
[0054]
As the polyester base film used in the present invention, an unstretched film is suitable for applications requiring strict moldability. Further, from the viewpoint of heat resistance and dimensional stability, a biaxially stretched polyester film is preferable. Such a biaxial stretching method may be any of simultaneous biaxial stretching and sequential biaxial stretching.
[0055]
The polyester base film can be formed into a laminated structure by a known method using different kinds of polyesters. The lamination structure of the base film is not particularly limited, and examples thereof include two types of two layers of A / B, two types of three layers of B / A / B, and three types of three layers of C / A / B.
[0056]
The method for producing the polyester base film is not particularly limited. For example, after drying the polyester as necessary, the polyester is supplied to a known melt extruder, extruded into a sheet from a slit die, and applied with static electricity. After the unstretched sheet is brought into close contact with the casting drum by cooling and solidified by cooling to obtain an unstretched sheet, the unstretched sheet is biaxially stretched.
[0057]
Such a stretching method may be either simultaneous biaxial stretching or sequential biaxial stretching. In short, the unstretched sheet is stretched in the machine direction (MD) and width direction (TD) of the film, and heat-treated to obtain a desired surface. A method for obtaining a biaxially stretched film having a degree of internal orientation is employed. Among these methods, in terms of film quality, successive secondary methods such as the MD / TD method in which the film is stretched in the longitudinal direction and then the film is 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. Further, if necessary, a multi-stage stretching method in which stretching in the same direction is divided into multiple stages may be used.
[0058]
The film stretching ratio at the time of biaxial stretching is preferably 1.6 to 4.2 times in the longitudinal direction and the width direction, and particularly preferably 1.7 to 4.0 times. In this case, either the stretching ratio in the longitudinal direction or the stretching direction in the width direction may be increased, or may be the same.
[0059]
In the laminated polyester film of the present invention, as a raw material of the base film, (1) a copolymerized polyester composed of terephthalic acid and ethylene glycol or neopentyl glycol, or (2) terephthalic acid and ethylene glycol, 1,4-cyclohexanedimethanol When the copolymerized polyester consisting of is used, in order to make the stress at 100% elongation in the longitudinal direction and the width direction at 100% elongation of 180 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C., the stretching ratio in the longitudinal direction is 2. It is preferable that the stretching is carried out at 8 to 4.0 times and the stretching ratio in the width direction is 3.0 to 4.5 times.
[0060]
The stretching conditions for producing the laminated polyester film of the present invention are not particularly limited. However, in order to satisfy the range of the stress at 100% elongation at 25 ° C. and 100 ° C. specified in the present invention, it is preferable to adopt, for example, the following conditions.
[0061]
In the longitudinal stretching, the stretching temperature is preferably 50 to 110 ° C. and the stretching ratio is preferably 1.5 to 4.0 times so that the subsequent transverse stretching can be performed smoothly.
[0062]
In the transverse stretching, the stress at 100% elongation in the longitudinal direction and the width direction is particularly important in order to be 180 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C.
[0063]
Normally, when stretching polyethylene terephthalate, if the stretching temperature is lower than appropriate conditions, the yield stress rapidly increases at the beginning of the transverse stretching, so that stretching cannot be performed. Further, even if stretching is possible, it is not preferable because the thickness and the stretching ratio tend to be non-uniform.
[0064]
In addition, when the stretching temperature is higher than appropriate conditions, the initial stress becomes lower, but the stress does not increase even when the stretching ratio becomes higher. Therefore, a film having a small stress at 100% elongation at 25 ° C. is obtained. Therefore, by setting the optimum stretching temperature, a film with high orientation can be obtained while ensuring stretchability.
[0065]
However, when the copolymerized polyester contains 1 to 40 mol% of a copolymer component, the stretching stress rapidly decreases as the stretching temperature is increased so as to eliminate the yield stress. In particular, since the stress does not increase even in the latter half of the stretching, the orientation does not increase, and the stress at 100% extension at 25 ° C. decreases.
[0066]
Such a phenomenon easily occurs 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 a polyester obtained by copolymerizing neopentyl glycol or 1,4-cyclohexanedimethanol, the stretching temperature in the transverse direction is preferably set to the following conditions.
[0067]
First, the preheating temperature is 90 to 120 ° C., in the first half of the transverse stretching, the stretching temperature is +5 to 25 ° C. with respect to the preheating temperature, and in the second half of the transverse stretching, the stretching temperature is − A range from 15 to -40C is preferred. By adopting such a condition, in the first half of the transverse stretching, the yield stress is small, so that the stretching is easy, and in the second half, the orientation is easy. The stretching ratio in the transverse direction is preferably 2.5 to 5.0 times. As a result, it is possible to obtain a film having a stress at 100% elongation in the longitudinal direction and the width direction of 180 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C.
[0068]
Further, the film is subjected to heat treatment after biaxial stretching, and this heat treatment can be carried out 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 the 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 is preferably performed for 1 to 60 seconds. The heat treatment may be performed while relaxing the film in the longitudinal direction and / or the width direction. In order to reduce the heat shrinkage in the longitudinal and transverse directions 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 heat treatment time by lengthening the line due to equipment restrictions. Further, if the film feeding speed is reduced, the productivity is reduced.
[0069]
In order to reduce the heat shrinkage in the longitudinal direction and the width direction at 150 ° C. to 3.0% or less, it is preferable to perform the heat treatment at a temperature of 200 to 220 ° C. while relaxing at a relaxation rate of 1 to 8%. Further, re-stretching may be performed once or more in each direction, and then heat treatment may be performed.
[0070]
In the laminated polyester film of the present invention, it is necessary to provide an adhesive property modification layer on at least one surface of the polyester base film in order to enhance printability.
[0071]
As a method of providing the adhesion modifying layer on the surface of the substrate film, a method of applying an aqueous coating solution containing the adhesion modifying resin to the surface of the substrate film, or a method of coextruding the adhesion modifying resin to the substrate. A method of laminating on a film may be used. Above all, the former method of applying an aqueous coating solution containing an adhesive property-modifying resin to the surface of a substrate film, the adhesion between the adhesive property-modifying layer and the printing ink layer, or other functionality-imparting layers in the present invention. This is the most effective method in terms of sex.
[0072]
Further, in order to further improve the adhesion between the base film and the adhesion-modified layer, the surface of the base film may be surface-treated in advance, and the adhesion-modified layer may be provided on the surface-treated surface. Examples of the surface treatment method include (1) a method by irradiation with active energy rays such as a corona discharge treatment, a plasma discharge treatment, an ultraviolet (UV) irradiation treatment, and a radiation (EB) irradiation treatment; (2) a flame treatment; ) A vapor deposition method such as PVD or CVD.
[0073]
As the resin constituting the adhesion improving layer, a resin made of at least one selected from polyester, polyurethane, acrylic polymer and / or a copolymer thereof is preferable. Further, when particles are not substantially contained in the base film, one or more kinds of particles are contained in the adhesion modified layer from the viewpoint of improvement in handling properties (slipperiness, rollability, blocking resistance, etc.). Preferably.
[0074]
Examples of the polyester resin constituting the adhesive property-modifying layer include, for example, 0.5 to 15.0 mol% of a dicarboxylic acid containing a metal sulfonic acid base and 85.0 to 99.5 of a dicarboxylic acid containing no metal sulfonic acid base. Water-insoluble polyester copolymers obtained by reacting two kinds of dicarboxylic acids with the polyol component by mol% are exemplified.
[0075]
Examples of the sulfonic acid metal base-containing dicarboxylic acids include metal salts such as 5-sulfoisophthalic acid, 4-sulfoterephthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, and 5 [4-sulfophenoxy] isophthalic acid. Particularly preferred are 5-sodium sulfoisophthalic acid and 4-sodium sulfoterephthalic acid.
[0076]
It is preferable that the content of the sulfonic acid metal base-containing dicarboxylic acid component is 0.5 to 15.0 mol% based on all dicarboxylic acid components. The lower limit of the composition ratio of the sulfonic acid metal base-containing dicarboxylic acid component to the total dicarboxylic acid component is particularly preferably 2.0 mol% from the viewpoint of dispersibility in water, and the upper limit is preferably 10 mol% from the viewpoint of water resistance. It is particularly preferred that the content be 0.0 mol%. If the composition ratio is less than 0.5 mol%, the dispersibility in water tends to be significantly reduced. On the other hand, when the composition ratio exceeds 15.0 mol%, the dispersibility in water is improved, but the water resistance of the polyester copolymer is liable to be significantly reduced.
[0077]
The dispersibility of the polyester copolymer in water varies depending on the type and the mixing ratio of the copolymer components, but the amount of the dicarboxylic acid component containing a sulfonic acid metal base is preferably small as long as the dispersibility in water is not impaired.
[0078]
As the dicarboxylic acid component containing no sulfonic acid metal base, aromatic, alicyclic, and aliphatic dicarboxylic acids can be used. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, and 2,6-naphthalenedicarboxylic acid. The content of these aromatic dicarboxylic acid components is preferably 40 mol% or more of the total dicarboxylic acid components. If the amount of the aromatic dicarboxylic acid component is less than 40 mol% based on the total dicarboxylic acid components, the mechanical strength and water resistance of the polyester copolymer tend to decrease.
[0079]
Examples of the aliphatic or alicyclic dicarboxylic acid include succinic acid, adipic acid, sebacic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. When such an aliphatic or alicyclic dicarboxylic acid component is contained, the adhesiveness may be increased, but generally, the mechanical strength and the water resistance of the polyester copolymer tend to decrease.
[0080]
The polyol components to be reacted with the above two kinds of dicarboxylic acids include (1) ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6- Aliphatic glycols having 2 to 8 carbon atoms such as hexanediol, and (2) 6 to 12 carbon atoms such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol. Alicyclic glycol, (3) aromatic glycol such as p-xylylene glycol, (4) glycol having an ether bond such as diethylene glycol, triethylene glycol, (5) polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Polyether, etc. It is. Further, a copolymer of an oxycarboxylic acid component such as p-oxyethoxybenzoic acid may be used.
[0081]
Further, as a polyester-based resin constituting the adhesion-modified layer, 0.5 to 15.0 mol% of a dicarboxylic acid containing an unsaturated group and 85.0 to 99.5 mol% of a dicarboxylic acid containing no unsaturated group are used. A resin obtained by reacting a water-insoluble polyester copolymer obtained by reacting two kinds of dicarboxylic acid components with a polyol component with an unsaturated bond-containing monomer.
[0082]
Examples of the unsaturated group-containing dicarboxylic acids include fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid, 2,5-norbornene dicarboxylic acid, and 4-cyclohexene-1,2-dicarboxylic acid. Among these unsaturated group-containing dicarboxylic acids, fumaric acid and maleic acid are particularly preferred.
[0083]
It is preferable that the content of the unsaturated group-containing dicarboxylic acid component is 0.5 to 15.0 mol% based on all dicarboxylic acid components. The composition ratio of the unsaturated group-containing dicarboxylic acid component to the total dicarboxylic acid component is particularly preferably set to a lower limit of 2.0 mol% from the viewpoint of water-solubility or water-dispersion of the resin. Therefore, it is particularly preferable to set the upper limit to 10.0 mol%. When the composition ratio is less than 0.5 mol%, graft modification is not sufficiently performed, and it is difficult to obtain a water-soluble or water-dispersible resin. On the other hand, if the composition ratio exceeds 15.0 mol%, a gel is generated by graft modification, and it becomes difficult to obtain a resin suitable for coating.
[0084]
As the dicarboxylic acid component containing no unsaturated group, aromatic, alicyclic and aliphatic dicarboxylic acids can be used. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, 4-sulfoterephthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5 [4-sulfophenoxy] isophthalic acid and the like can be mentioned.
[0085]
The content of these aromatic dicarboxylic acids is preferably at least 40 mol% with respect to the total dicarboxylic acid components, and if it is less than 40 mol%, the mechanical strength and water resistance of the polyester copolymer tend to decrease.
[0086]
Examples of the aliphatic or alicyclic dicarboxylic acid include succinic acid, adipic acid, sebacic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. When such an aliphatic or alicyclic dicarboxylic acid component is contained, the adhesiveness may be increased, but generally, the mechanical strength and the water resistance of the polyester copolymer tend to decrease.
[0087]
The polyol components to be reacted with the above two kinds of dicarboxylic acids include (1) ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6- Aliphatic glycols having 2 to 8 carbon atoms such as hexanediol, and (2) 6 to 12 carbon atoms such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol. Alicyclic glycol, (3) aromatic glycol such as p-xylylene glycol, (4) glycol having an ether bond such as diethylene glycol, triethylene glycol, (5) polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Polyether, etc. It is. Further, a copolymer of an oxycarboxylic acid component such as p-oxyethoxybenzoic acid may be used.
[0088]
As the unsaturated group-containing monomer used for graft-modifying the above-mentioned unsaturated polyester, a monomer which is polymerized by a radical is preferable. For example, acrylic acid, acrylic esters (methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, etc.), methacrylic acid , Methacrylates (methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, etc. ), Acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-methylolacrylamide, diacetoneacrylamide, vinyl acetate, vinyl ethers, N-vinylpi Loridone, styrene, α-methylstyrene, t-butylstyrene, vinyltoluene, maleic anhydride and the like.
[0089]
The above monomers can be used alone or in combination of two or more. Preferably, a resin graft-modified with a monomer containing acrylic acid and ethyl acrylate, and a resin graft-modified with a monomer containing styrene and maleic anhydride have a water-dispersibility, an adhesion-modified layer and a base film. It is preferable from the viewpoint of improving the adhesion to the printing ink layer, heat resistance, and water resistance.
[0090]
For the graft modification, the methods disclosed in JP-A-6-256737 and JP-A-7-330841 can be used.
[0091]
Examples of the urethane-based resin constituting the adhesive property-modifying layer include a heat-reactive water-soluble urethane in which a terminal isocyanate group is blocked by a hydrophilic group. Numerous compounds such as bisulfites, phenols, alcohols, lactams, oximes, and active methylene compounds containing a sulfone group can be used as the isocyanate group blocking agent.
[0092]
The blocked isocyanate group renders the urethane prepolymer hydrophilic or water-soluble, and the blocking agent is removed from the molecular chain by drying or heat setting during film production. That is, when heat energy is applied to the polymer containing the blocked isocyanate group, the blocking agent is separated from the isocyanate group, and the polymer self-crosslinks. The polymer at the time of the coating liquid preparation is poor in water resistance because it is hydrophilic, but when coating, drying, and heat setting are completed and the thermal reaction is completed, the hydrophilic group of the urethane polymer comes off, and the water resistance is good. A coating is obtained.
[0093]
Of the above blocking agents, bisulfites are preferable as those which are suitable for heat treatment temperature and heat treatment time and are widely used industrially. The urethane prepolymer used in the urethane-based polymer includes (1) a compound having two or more active hydrogen atoms in a molecule and having a molecular weight of 200 to 20,000, and (2) two compounds in a molecule. The organic polyisocyanate having an isocyanate group described above and (3) a compound having a terminal isocyanate group obtained by reacting a chain extender having at least two active hydrogen atoms in a molecule are exemplified.
[0094]
What is generally known as the compound of the above (1) is a compound containing two or more hydroxyl groups, carboxyl groups, amino groups, or mercapto groups at the terminal or in the molecule. Among them, polyether polyols, polyester polyols, polyether ester polyols and the like are particularly preferred.
[0095]
Examples of polyether polyols include compounds obtained by polymerizing alkylene oxides such as ethylene oxide and propylene oxide, or styrene oxide and epichlorohydrin, and random copolymerization, block copolymerization, or addition polymerization to polyhydric alcohols. There are obtained compounds and the like.
[0096]
Examples of the polyester polyol and the polyether ester polyol include mainly linear or branched compounds. Saturated and unsaturated, such as succinic acid, adipic acid, phthalic acid, or their anhydrides, and ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, and trimethylolpropane And polyalkylene ether glycols such as polyethylene glycol and polypropylene glycol having a relatively low molecular weight, and mixtures thereof.
[0097]
Further, as polyester polyols, polyesters obtained from lactones and hydroxy acids, and as polyetherester polyols, use may be made of polyetheresters obtained by adding ethylene oxide or propylene oxide to polyesters produced in advance. Can be.
[0098]
Examples of the organic polyisocyanate (2) include (a) isomers of toluylene diisocyanate, (b) aromatic diisocyanates such as 4,4-diphenylmethane diisocyanate, and (c) aromatic aliphatic isocyanates such as xylylene diisocyanate. Diisocyanates; (d) alicyclic diisocyanates such as isophorone diisocyanate and 4,4-dicyclohexylmethane diisocyanate; (e) aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate; And polyisocyanates in which one or more of these compounds are added in advance to trimethylolpropane or the like.
[0099]
Examples of the chain extender having at least two active hydrogens in the above (3) include (a) glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol; and (b) glycerin. , Trimethylolpropane, and polyhydric alcohols such as pentaerythritol; (c) diamines such as ethylenediamine, hexamethylenediamine, and piperazine; (d) aminoalcohols such as monoethanolamine and diethanolamine; Thiodiglycols such as diethylene glycol; and (f) water.
[0100]
Examples of the polyacrylic resin constituting the adhesive property modifying layer include those obtained by polymerizing monomers other than acrylic acid or a derivative thereof and, if necessary, acrylic acid (derivative) having a vinyl group. You.
[0101]
Examples of the monomer include acrylic acid, methacrylic acid (hereinafter, acrylic acid and / or methacrylic acid are referred to as (meth) acrylic acid), and lower alkyl esters of (meth) acrylic acid (eg, methyl, ethyl, propyl, Butyl, amyl, hexyl, heptyl, octyl, 2-ethylhexyl ester), methyl methacrylate, hydroxymethyl acrylate, styrene, glycidyl methacrylate, methyl acrylate, ethyl acrylate and the like.
[0102]
In addition, it is also possible to appropriately add a catalyst compound having a reaction promoting effect of the respective crosslinking agent or curing agent, and various known techniques can be used for this purpose.
[0103]
The self-crosslinking resin can be selected from resins usable as the crosslinking agent or the curing agent. In particular, water-soluble or water-dispersible methylol melamine resins, urea formalin resins, and resins such as polyethers, polyesters, polyether urethanes, and polyether esters to which polyfunctional blocked isocyanate groups are added are preferred. Further, a curing catalyst can be used as needed.
[0104]
Among the resin compositions constituting the adhesion modifying layer, a water-insoluble and water-dispersible polyester resin containing a sulfone group in the molecule and a water-soluble polyurethane resin having at least one block isocyanate in the molecule A laminated polyester film provided with an adhesion modifying layer made of an adhesion modifying resin mixed with a resin is excellent in heat resistance when subjected to heat molding processing. It is particularly preferable since the adhesiveness with a printing ink such as an ultraviolet (UV) curable ink and an oxidation polymerization ink can be greatly improved.
[0105]
In this case, the content of the water-insoluble and water-dispersible polyester resin (A) and the water-soluble polyurethane resin (B) is (A) / (B) = 90/10 to 10/90 by mass ratio. It is preferable that the ratio is (A) / (B) = 80/20 to 20/80 in terms of mass ratio.
[0106]
As a method of providing the adhesive property modification layer, as described above, a method of applying a coating solution containing an adhesive property modifying resin composition containing an adhesive property modifying resin as a main component to a polyester base film surface. preferable.
[0107]
At this time, the liquid temperature of the coating liquid is preferably controlled at 10 ° C to 20 ° C, and particularly preferably set at 12 ° C to 18 ° C. The pH of the coating solution is preferably adjusted to 5.5 to 7.5, and particularly preferably 6.0 to 7.0.
[0108]
When the liquid temperature or pH of the coating liquid is out of the above range, when particles are contained in the coating liquid, the inert particles in the coating liquid are easily aggregated, and the production is caused by clogging of the filter in the coating liquid circulation system. This tends to cause a decrease in the adhesiveness and a decrease in the powder fall resistance of the adhesion-modified layer. Further, the stability over time (pot life) of the coating solution is liable to decrease.
[0109]
Further, before applying the coating solution to the base film, the coating solution is filtered using a filter such as a wire mesh, a bag-type filter, a thread-wound filter, a cartridge-type filter, and the like, so that coarse particles, aggregated particles, and contaminants are removed. It is preferable to remove such.
[0110]
In this way, by controlling the liquid temperature and pH of the coating liquid within the above ranges, or by filtering the coating liquid using the filter, the printed appearance is provided when a printing layer is provided on the laminated polyester film. Can be good.
[0111]
In addition, as a method of applying the coating liquid for the adhesive property modifying layer to the base film, a roll coating method such as a gravure coating, a reverse coating, a kiss coating, a reverse kiss coating, a bar coating method, an air knife method, a blade coating method, and a comma coating method. A commonly used method such as a coat (roll knife coat) method, a curtain coat method, a spray method, and a dipping method can be applied.
[0112]
As a step of applying to a polyester film, a method of pre-coating on an unstretched film surface, a method of orienting in a uniaxial direction and then coating on a film surface, a method of orienting in a perpendicular direction, and a method of applying on a film surface after biaxial orientation Any method such as a method is possible. Above all, the method of applying to the uniaxially oriented polyester film surface and then stretching and orienting in the perpendicular direction to complete the crystallization is excellent in terms of heat resistance, adhesiveness, economy, cleanliness during molding processing, most This is the preferred method.
[0113]
The laminated polyester film of the present invention is particularly preferably used for molding applications. The polyester film for molding is used by being deformed by applying heat, pressure or the like. Examples of the forming means include air pressure forming, press forming, laminate forming, vacuum forming, vacuum pressure forming, in-mold forming, draw forming, and bending forming. The molded body formed in this manner is suitable as a molded member such as a nameplate for a home appliance, a nameplate for an automobile, a dummy can, a building material, a decorative plate, a decorative steel plate, a transfer sheet, and the like.
[0114]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples. The properties of the films obtained in the examples were measured and evaluated by the following methods.
[0115]
(1) Intrinsic viscosity
0.1 g of the chip sample was precisely weighed, dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane = 6/4 (mass ratio), and measured at 30 ° C. using an Ostwald viscometer. The measurement was performed three times, and the average value was obtained.
[0116]
(2) Thickness unevenness
A continuous tape-shaped sample having a length of 3 m in the horizontal stretching direction and 5 cm in the vertical stretching direction is wound up, and the thickness of the film is measured by a film thickness continuous measuring machine (manufactured by Anritsu Corporation) and recorded on a recorder. From the chart, the maximum value (dmax), minimum value (dmin), and average value (d) of the thickness were obtained, and the thickness unevenness (%) was calculated by the following equation. The measurement was performed three times, and the average value was obtained. If the length in the transverse stretching direction is less than 3 m, the joining is performed. Note that the connection portion is deleted from the data.
Thickness unevenness (%) = ((dmax−dmin) / d) × 100
[0117]
(3) Haze
It was measured using a haze meter (300A, manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS-K7136. The measurement was performed twice, and the average value was obtained.
[0118]
(4) Film thickness
Using a Millitron, 15 points were measured on a total of 3 pieces, 5 points per sheet, and the average value was obtained.
[0119]
(5) Stress at 100% elongation, elongation at break
With respect to the longitudinal direction and the width direction of the biaxially stretched film, a sample is cut out into a strip shape having a length of 180 mm and a width of 10 mm with a single-edged razor, and the sample is cut using a tensile tester (manufactured by Toyo Seiki Co., Ltd.). From the obtained load-strain curve, the stress at 100% elongation (MPa) and elongation at break (%) in each direction were determined.
[0120]
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 chart speed of a recorder of 200 mm / min, and a load cell of 25 kg. The measurement was performed 10 times and the average value was used.
[0121]
Further, a tensile test was performed under the same conditions as above even in an atmosphere at 100 ° C. At this time, the sample was held in an atmosphere at 100 ° C. for 30 seconds and then measured. The measurement was performed 10 times and the average value was used.
[0122]
(6) Heat shrinkage 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 provided at 200 mm intervals in the length direction of each sample, and the distance A between the two marks is measured under a constant tension of 5 g (longitudinal tension). Subsequently, one side of each of the strip-shaped samples is hung by a clip with no load in a basket, placed in a gear oven in an atmosphere of 150 ° C., and timed. After 30 minutes, remove the basket from the gear oven and leave at room temperature for 30 minutes. Then, for each sample, the interval B between the two marks is read in 0.25 mm units with a gold finger under a constant tension (tension in the length direction) of 5 g. From the read intervals A and B, the thermal shrinkage at 150 ° C. of each sample is calculated by the following equation.
Heat shrinkage (%) = ((AB) / A) × 100
[0123]
(7) Formability
After printing on the film, the film was heated at 130 ° C. for 5 seconds, and then press-formed at a mold temperature of 80 ° C. and a dwell time of 5 seconds. An ABS resin was poured into the molding material at 210 ° C. (injection molding) to prepare a key top having a surface covered with a film and having a height of 3.0 mm. The printing deviation at this time was measured, and the molded state was visually observed, and ranked according to the following criteria. In addition, ◎ and ○ were regarded as pass, and × was rejected.
[0124]
A: The printing deviation is 0.1 mm or less, and the appearance is extremely good.
：: When printing misalignment is 0.1 mm or more and 0.2 mm or less, some wrinkles are observed, but this is a level that does not cause any practical problem.
X: The printing deviation exceeds 0.2 mm. Alternatively, the film is broken. Alternatively, large wrinkles are formed and the appearance is remarkably poor.
[0125]
(8) Printability
The film before printing was heat-treated at 90 ° C. for 30 minutes, and then screen-printed in four colors. Further, the film provided with the printing layer was dried at 80 ° C. for 30 minutes. The printability was evaluated based on the following criteria by visually evaluating print deviation and print clarity. In addition, ◎ and ○ were regarded as pass, and × was rejected.
[0126]
◎: Excellent in print clarity, and no print misregistration in each color is visually observed.
：: Some printing misregistration is observed when visually observed at a position of about 20 cm, but the appearance is generally good when separated by 20 cm or more, which is a practically usable level.
×: Printing shift in each color is observed, or printing is uneven, and the appearance is extremely poor.
[0127]
Example 1
(Adjustment of coating liquid)
A water-soluble urethane resin having a solid content of 3.15% by mass of a copolymerized polyester resin (manufactured by Toyobo Co., Ltd., Vironal MD-1250) in an aqueous solution of 40% by mass of isopropanol and a terminal isocyanate group blocked with a hydrophilic group (No. 1) The coating liquid was adjusted so that 5.85% by mass of Elastron H-3) (manufactured by Kogyo Seiyaku Co., Ltd.) as solids and 12.5% by mass of silica particles having an average particle size of 0.45 μm based on all resins. did. The obtained coating solution was adjusted to pH 6.5 using a 5% by mass aqueous sodium bicarbonate solution. Next, the mixture was filtered with a bag-type filter (Liquid Filter Bag, manufactured by Sumitomo 3M Limited) and stirred at 15 ° C. for 2 hours in a coating tank for a coating solution circulation system.
[0128]
(Manufacture of laminated film)
Preliminary crystallization of a copolyester having an intrinsic viscosity of 0.69 dl / g, comprising 100 mol% of terephthalic acid units as an aromatic dicarboxylic acid component, 85 mol% of ethylene glycol units and 15 mol% of neopentyl glycol units as diol components. After the formation, this was dried, melt-extruded at 280 ° C. using an extruder having a T-die, and rapidly solidified on a drum having a surface temperature of 40 ° C. to obtain an amorphous sheet.
[0129]
The obtained sheet was stretched 3.5 times at 80 ° C. in the longitudinal direction between a heating roll and a cooling roll. The coating solution was applied to one surface of the obtained uniaxially stretched film by a reverse kiss coating method so that the resin solid content thickness before stretching was 0.9 μm. The film having the coating layer is guided to a tenter while being dried, preheated at 100 ° C. for 15 seconds, and the first half of the transverse stretching is stretched 3.6 times at 115 ° C. and the second half at 95 ° C., and the transverse relaxation is 7%. And a heat treatment was performed at 205 ° C. to obtain a laminated biaxially oriented polyester film having a thickness of 188 μm. Table 1 shows the properties and evaluation results of the obtained film.
[0130]
Comparative Example 1
Containing 100 mol% of terephthalic acid units as an aromatic dicarboxylic acid component, 85 mol% of ethylene glycol units and 15 mol% of neopentyl glycol units as diol components, and contains 400 ppm of amorphous silica having an average particle diameter of 1.5 μm. After pre-crystallization of a copolyester having an intrinsic viscosity of 0.69 dl / g, this was pre-crystallized, dried, melt-extruded at 280 ° C. using an extruder having a T-die, and rapidly cooled and solidified on a drum having a surface temperature of 40 ° C. A fixed sheet was obtained.
[0131]
The obtained sheet was stretched 3.5 times at 80 ° C. in the longitudinal direction between a heating roll and a cooling roll. The obtained uniaxially stretched film was guided to a tenter and preheated at 100 ° C. for 15 seconds. The first half of the transverse stretching was stretched 3.6 times at 115 ° C. and the latter half at 95 ° C. to relax 7% in the transverse direction. A heat treatment was performed at 205 ° C. while maintaining the temperature to obtain a biaxially oriented polyester film having a thickness of 188 μm. Table 1 shows the properties and evaluation results of the obtained film.
[0132]
Comparative Example 2
A laminated biaxially stretched polyester film was obtained in the same manner as in Example 1, except that the content of the amorphous silica in the coating solution was changed from 12.5% by mass to 30% by mass. Table 1 shows the properties and evaluation results of the obtained film.
[0133]
Comparative Example 3
In Example 1, 100 mol% of terephthalic acid units as aromatic dicarboxylic acid components, 85 mol% of ethylene glycol units and 15 mol% of neopentyl glycol units as diol components were used as raw materials for the film, and the average particle diameter was 1 A laminated biaxially oriented polyester film was obtained in the same manner as in Example 1, except that a copolymerized polyester having an intrinsic viscosity of 0.69 dl / g and containing 400 ppm of amorphous silica having a particle size of 0.5 μm was used. Table 1 shows the properties and evaluation results of the obtained film.
[0134]
Comparative Example 4
Preliminary crystallization of polyethylene terephthalate having an intrinsic viscosity of 0.69 dl / g, comprising 100 mol% of terephthalic acid units as an aromatic dicarboxylic acid component and 100 mol% of ethylene glycol units as a diol component, followed by main drying and extrusion with a T die It was melt-extruded at 280 ° C. using a machine and quenched and solidified on a drum having a surface temperature of 40 ° C. to obtain an amorphous sheet.
[0135]
The obtained sheet was stretched 3.7 times at 90 ° C. between the heating roll and the cooling roll. The coating liquid was applied to one surface of the obtained uniaxially stretched film by a reverse kiss coating method so that the resin solid content thickness before stretching was 0.9 μm. The film having the coating layer is guided to a tenter while drying, 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 stretched 4.0 times at 120 ° C., and the transverse relaxation is 10%. And a heat treatment was performed at 200 ° C. to obtain a laminated biaxially stretched polyester film having a thickness of 188 μm. Table 1 shows the properties and evaluation results of the obtained film.
[0136]
Example 2
Preliminary crystallization of a copolyester having an intrinsic viscosity of 0.71 dl / g, comprising 100 mol% of terephthalic acid units as an aromatic dicarboxylic acid component, 75 mol% of ethylene glycol units and 25 mol% of cyclohexanedimethanol units as diol components. After the formation, this was dried, melt-extruded at 280 ° C. using an extruder having a T-die, and rapidly solidified on a drum having a surface temperature of 40 ° C. to obtain an amorphous sheet.
[0137]
The obtained sheet was stretched 3.0 times at 75 ° C. between a heating roll and a cooling roll. The coating liquid was applied to one surface of the obtained uniaxially stretched film by a reverse kiss coating method so that the resin solid content thickness before stretching was 0.9 μm. The film having the coating layer is guided to a tenter while being dried, preheated at 105 ° C. for 15 seconds, and the first half of the transverse stretching is stretched at 125 ° C. and the latter half at 98 ° C. by 3.6 times, and the transverse relaxation is reduced by 7%. And a heat treatment was performed at 205 ° C. to obtain a laminated biaxially oriented polyester film having a thickness of 188 μm. Table 1 shows the properties and evaluation results of the obtained film.
[0138]
Example 3
In Example 1, 100 mol% of terephthalic acid units as an aromatic dicarboxylic acid component and 60 mol% of an ethylene glycol unit and 40 mol% of a neopentyl glycol unit as a diol component were used, each having an intrinsic viscosity of 0.69 dl / g. Same as Example 1 except that the polymerized polyester and polyethylene terephthalate having an intrinsic viscosity of 0.69 dl / g were dried and pre-crystallized, respectively, and then chip-blended at a ratio of 50:50 (mass ratio). Thus, a biaxially stretched polyester film was obtained.
[0139]
Comparative Example 3
It contains 90 mol% of terephthalic acid units and 10 mol% of adipic acid as a dicarboxylic acid component, 100 mol% of ethylene glycol units as a diol component, and contains 800 ppm of amorphous silica having an average particle diameter of 1.4 μm. A biaxially stretched polyester film was obtained in the same manner as in Example 1, except that a copolymerized polyester of 0.71 dl / g was used.
[0140]
Example 4
(Adjustment of coating liquid)
The dicarboxylic acid component is composed of 50 mol% of terephthalic acid units, 45 mol% of isophthalic acid units, 5 mol% of fumaric acid, and 50 mol% of ethylene glycol units and 50 mol% of neopentyl glycol as diol components. Styrene as a monomer, 10 parts by weight of maleic anhydride, and azobisisobutyronitrile as a polymerization initiator in an amount of 6 parts by mass based on 80 parts by mass of a polyester of .50 dl / g. The graft modification was carried out in a 2-butanone solution containing 20% by mass of isopropanol at a temperature of 80 ° C.
[0141]
After the graft reaction, the acid anhydride (maleic anhydride) site was opened with ethanol and neutralized with ammonia. Then, the solvent was replaced with water to obtain a graft-modified polyester resin dispersion having a number average molecular weight measured by GPC of 17,000, a resin acid value before neutralization of 900 eq / ton, and a solid content concentration of 25% by mass. .
[0142]
(Manufacture of laminated film)
A laminated polyester film was obtained in the same manner as in Example 1 except that the graft-modified polyester resin dispersion obtained above was used as a coating liquid. Table 1 shows the properties and evaluation results of the obtained film.
[0143]
Example 5
As a coating solution, an acrylic resin (manufactured by Dainippon Ink and Chemicals, Inc., Boncoat R-3380A) and a melamine resin (manufactured by Sumitomo Chemical Co., Ltd., Sumimar M-40W) were each used in a weight ratio of resin solids of 70/30. A laminated polyester film was obtained in the same manner as in Example 1 except that a mixture was used so that Table 1 shows the properties and evaluation results of the obtained film.
[0144]
[Table 1]

[0145]
Example 6
The laminated polyester film obtained in Example 1 was press-molded at a mold temperature of 100 ° C. to produce a switch nameplate having a depth of 2.0 mm. The appearance of the obtained nameplate was good.
[0146]
【The invention's effect】
In the laminated polyester film of the present invention, a film having excellent workability, printability, and transparency can be obtained by providing a coating layer on a film in which haze and stress at the time of 100% elongation in the longitudinal and width directions of the film are controlled. Is completed.
[0147]
【The invention's effect】
Since the laminated polyester film of the present invention independently controls the stress at 100% elongation in the longitudinal direction and the width direction of the film at 25 ° C. and 100 ° C., the moldability at the time of heating and the use as a molded article Is excellent in form stability (elasticity, strength, heat shrinkage characteristics, thickness unevenness). Further, since it has in-mold moldability, emboss moldability, and vacuum moldability, it is particularly suitable as a polyester film for molding. Furthermore, by laminating the adhesion modified layer on the base film, the printability (print clarity, print misregistration) when the printed layer is provided on the adhesion modified layer surface in order to enhance the design of the molded product is improved. I have. Therefore, the laminated polyester film for molding is a molded member suitable for members for home appliances, automobile nameplates, building materials, and the like.

Claims (10)

At least one surface of a polyester base film containing a copolyester composed of an aromatic dicarboxylic acid component and a glycol component containing ethylene glycol, a branched aliphatic glycol and / or an alicyclic glycol, and an adhesion-modified layer Wherein the ratio (H / d) of the haze H (%) to the thickness d (μm) is 0.020 or less, and the laminated film has a longitudinal direction and a width direction. Wherein the stress at 100% elongation is 180 to 1000 MPa at 25 ° C. and 1 to 100 MPa at 100 ° C. 2. The laminated polyester film according to claim 1, wherein the branched aliphatic glycol is neopentyl glycol. 3. The laminated polyester film according to claim 1, wherein the alicyclic glycol is 1,4-cyclohexanedimethanol. 4. The laminated polyester film according to any one of claims 1 to 3, wherein the aromatic dicarboxylic acid component is terephthalic acid, naphthalenedicarboxylic acid, or an ester-forming derivative thereof. The film has a stress ratio (higher numerical value / lower numerical value) at 100% elongation in the longitudinal direction and the width direction at 100% (higher numerical value / lower numerical value) of 1.05 to 1.60. 5. The laminated polyester film according to any one of 4. The laminated polyester film according to any one of claims 1 to 5, wherein the film has a thickness of 60 to 500 µm. The laminated polyester film according to any one of claims 1 to 6, wherein the film has a thickness unevenness of 5.5% or less. The laminated polyester film according to any one of claims 1 to 7, wherein the film has a heat shrinkage in a longitudinal direction and a width direction at 150 ° C of 3.0% or less. A laminated polyester film for molding, wherein the laminated polyester film according to any one of claims 1 to 8 is used as a molded member. A molded member using the laminated polyester film for molding according to claim 9.