WO2022219970A1

WO2022219970A1 - Printed matter

Info

Publication number: WO2022219970A1
Application number: PCT/JP2022/009806
Authority: WO
Inventors: 武士久保; 栄二熊谷; 博多喜
Original assignee: 東洋紡株式会社
Priority date: 2021-04-12
Filing date: 2022-03-07
Publication date: 2022-10-20
Also published as: JPWO2022219970A1; TW202248376A

Abstract

[Problem] To provide printed matter which has favorable adhesiveness to various ink compositions while avoiding electrostatic damage in a printing step, and which maintains favorable adhesiveness without causing degradation of the adhesiveness between an ink layer and an easily adhesive layer even when printed, and then stored in a high-temperature and high-humidity environment. [Solution] This printed matter has an easily adhesive coating layer provided on a polyester film substrate, and is formed by laminating, on the easily adhesive coating layer, at least one ink layer selected from among UV-curable ink, solvent-type ink, oxidative polymerization-type ink, thermal transfer ink ribbon, and LBP toner, wherein the nitrogen ion concentration A (at%) and the nitrogen element ratio B (at%), as obtained on the basis of the surface element distribution measurement of the surface of the easily adhesive coating layer by X-ray photoelectron spectroscopy, satisfy a specific relationship, and the contact angle θ H₂O of the surface of the easily adhesive coating layer to water is within a specific range.

Description

printed matter

The present invention relates to printed matter with excellent adhesion to various ink layers. More specifically, we have developed a biaxially stretched polyester film base material with an easy-adhesion coating layer that is optimal for all types of ink layers, such as ultraviolet (UV) curable ink, solvent-based ink, oxidation polymerization ink, thermal transfer ink ribbon, and LBP toner. Regarding the adhesion with the active energy ray-curable ink layer, especially ultraviolet (UV) curable ink, when stored in a high-temperature and high-humidity environment after printing, the adhesion with the ink layer The present invention relates to a printed material having an easily adhesive coating layer which does not deteriorate in properties.

Polyester film has excellent properties such as mechanical properties, electrical properties, and dimensional stability. used as material film. In particular, it is indispensable for various commercial printing applications, labels, etc., in which printing is performed on film. However, polyester films have poor adhesiveness to printing inks, so it is common to provide an anchor coating layer using a resin having easy adhesiveness. Examples of the constituent resins of the coating layer include, for example, polyester resins, polyurethane resins, acrylic resins, etc., which are used singly or in combination of two or more; and the like. However, in general, both the polyester film surface of the substrate and the surface of the easy-adhesive coating layer provided for improving adhesion are easily charged, and problems related to the passage of the film-forming process and electrostatic interference in the processing process are caused. There are cases where there is a problem (see, for example, Patent Literature 1).

As a method to improve problems caused by static electricity, conductive polymers such as polyaniline and polypyrrole, particulate carbon black, metal powders such as nickel and copper, metal oxides such as tin oxide and zinc oxide, and fibrous brass are used in the coating layer. It is known to impart antistatic properties to the coating layer by incorporating conductive fillers such as metal-coated fibers such as stainless steel and aluminum, graphite flakes, aluminum flakes and copper flakes.

Alternatively, it is also known to incorporate a polymeric antistatic agent having at least one sulfonate group or phosphate group in the molecule into a coating agent and apply it to a substrate film (see, for example, Patent Document 2). ).

In recent years, printed matter as labels has become popular in a wide variety of fields. The global food market is on the rise, and food labels are spreading not only in developed countries but also in developing countries. In addition, the demand for caution labels used for industrial electronic members is increasing along with the increase in demand for industrial products. The printed matter is often used in high-temperature or high-humidity environments. However, when the printed material is stored under the above environment, the adhesion between the ink layer and the easy-adhesive coating layer of the base material decreases, and the printed part peels off, so the original role of the label may be lost.

Japanese Patent Application Laid-Open No. 2001-348450 JP 2011-156848 A

The present invention is a printed matter having an easy-adhesive coating layer on a polyester film base material, and further comprising an ink layer on the easy-adhesive coating layer, avoiding electrostatic failure in the printing process, and various It has good adhesion to the ink composition, and even when stored in a high temperature and high humidity environment after printing, the adhesion between the ink layer and the easy adhesion layer does not decrease, and good adhesion is maintained. The purpose is to provide printed matter that

In order to solve the above problems, the inventors have investigated the causes of the above problems and have completed the present invention. That is, the present invention consists of the following configurations.
1. It has an easy-adhesive coating layer on a polyester film substrate, and at least one layer selected from UV-curing ink, solvent-based ink, oxidation polymerization ink, thermal transfer ink ribbon, and LBP toner on the easy-adhesive coating layer. Nitrogen ion concentration A (at%) and nitrogen element ratio B (at%) based on surface element distribution measurement by X-ray photoelectron spectroscopy on the surface of the easy-adhesive coating layer The printed matter satisfies the following formulas (i) and (ii), and the contact angle θ H ₂ O of the easy-adhesive coating layer surface to water satisfies the following formula (iii).
(i) A (at%) > 0.4
(ii) 2.0 ≤ B/A ≤ 5.0
(iii) 50° _{≤θH2O≤70} °
2. 1. The printed matter according to 1 above, wherein the easily adhesive coating layer is obtained by curing a composition containing a cationic antistatic agent, a polyurethane resin and a polyester resin.
3. 3. The printed matter according to 1 or 2 above, wherein the polyester film substrate is a white polyester film substrate containing inorganic particles and/or a thermoplastic resin incompatible with the polyester resin.

According to the present invention, it is possible to avoid electrostatic failure in the printing process and to obtain various printed materials having good adhesion between the easily adhesive coating layer and the ink layer, and when stored in a high-temperature and high-humidity environment after printing. However, the adhesion between the substrate and the ink layer does not deteriorate, and good adhesion is maintained.

The nitrogen element ratio A (at%) derived from the antistatic agent based on surface element distribution measurement by X-ray photoelectron spectroscopy on the surface of the easy-adhesive coating layer in the present invention, and the nitrogen element ratio B (at%) derived from the polyurethane resin It is an explanatory diagram for obtaining and.

(Polyester film substrate)
The polyester resin constituting the polyester film substrate in the present invention includes polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polytrimethylene terephthalate and the like, as well as the diol component or dicarboxylic acid component of the polyester resin as described above. is a copolymerized polyester resin in which a part of is replaced with the following copolymerization components, for example, as copolymerization components, diol components such as diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, polyalkylene glycol , adipic acid, sebacic acid, phthalic acid, isophthalic acid, 5-sodium isophthalic acid, and dicarboxylic acid components such as 2,6-naphthalenedicarboxylic acid.

The polyester resin suitably used for the polyester film substrate in the present invention is mainly selected from polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate and polyethylene-2,6-naphthalate. Among these polyester resins, polyethylene terephthalate is most preferable from the viewpoint of balance between physical properties and cost. Moreover, the polyester film substrate composed of these polyester resins is preferably a biaxially oriented polyester film, which can improve chemical resistance, heat resistance, mechanical strength, stiffness, and the like.

The catalyst for polycondensation used in the production of polyester resin is not particularly limited, but antimony trioxide is suitable because it is inexpensive and has excellent catalytic activity. It is also preferable to use a germanium compound or a titanium compound. Further preferred polycondensation catalysts include catalysts containing aluminum and/or compounds thereof and phenolic compounds, catalysts containing aluminum and/or compounds thereof and phosphorus compounds, and catalysts containing aluminum salts of phosphorus compounds.

The base polyester film used in the present invention may have a single-layer structure or a multi-layer structure, but it is preferable that some or all of the layers are opaque. The optical density indicating the opacity of the polyester film is 0.3 or more, preferably 0.3 to 4.0, and particularly preferably 0.5 to 3.0. When the optical density is 0.3 or more, when printing is applied to the surface of the obtained polyester-based coating film, the printing effect becomes clear, which is preferable. Further, when the optical density is 4.0 or less, a better printing effect can be expected, which is preferable.

Although the method for obtaining the optical density within the above range is not particularly limited, it can be preferably achieved by incorporating inorganic particles or a thermoplastic resin incompatible with the polyester resin into the polyester resin. The content of these is not particularly limited, but in the case of inorganic particles, it is preferably 5 to 35% by mass, particularly preferably 8 to 25% by mass, based on the polyester produced. On the other hand, when an incompatible thermoplastic resin is contained, it is preferably 5 to 35% by mass, particularly preferably 8 to 28% by mass, based on the polyester. In addition, when inorganic particles and a thermoplastic resin incompatible with a polyester resin are used in combination, the total amount is 40% by mass or less with respect to the polyester film. It is preferable from the viewpoint of stability.

The layer structure of the base polyester film in the present invention may be a single layer structure or a laminated structure, but it is a laminated structure of X layer / Y layer / X layer, the X layer contains inorganic particles, and the Y layer contains inorganic particles. is a preferred embodiment to have a laminated structure containing microcavities. By arranging a layer containing inorganic particles on the X layer, which is the surface layer, it is possible to improve the slipperiness, that is, the handling property and the hiding property of the film, and the fine cavities are contained only in the Y layer, which is the inner layer. This makes it possible to ensure the strength of the film surface while exhibiting the cushioning properties of the film. Although the method for forming the laminated structure is not particularly limited, co-extrusion is preferable from the viewpoint of stability during production and processing costs.

The content of the inorganic particles contained in the X layer is preferably 2.5-70.0% by mass, particularly preferably 4.0-60.0% by mass, relative to the polyester. More preferably, it is 6.0 to 50.0% by mass. The content of the incompatible thermoplastic resin contained in the Y layer is preferably 5 to 35% by mass, particularly preferably 8 to 28% by mass, based on the polyester.

The thickness ratio of each layer in the laminated structure of X layer/Y layer/X layer is preferably in the range of 0.5/9/0.5 to 2/6/2 from the viewpoint of film strength, stiffness, and film forming stability. , 1/8/1 to 1.5/7/1.5.

Although the inorganic particles to be used are not particularly limited, inorganic particles having an average particle size of 0.1 to 4.0 μm are preferable, and inorganic particles having an average particle size of 0.3 to 1.5 μm are particularly preferable. Specifically, white pigments such as titanium oxide, barium sulfate, calcium carbonate, and zinc sulfide are preferred, and these may be mixed. In addition, inorganic particles commonly contained in films such as silica, alumina, talc, kaolin, clay, calcium phosphate, mica, hectorite, zirconia, tungsten oxide, lithium fluoride, calcium fluoride, calcium sulfate, etc. You can use them together.

The thermoplastic resin incompatible with the polyester resin is not particularly limited. Examples include resins, acrylic resins, phenoxy resins, polyphenylene oxide resins, polycarbonate resins, and the like. Further, these thermoplastic resins may be mixed or modified. Naturally, it can also be used in combination with the inorganic particles. It goes without saying that various whitening agents may be added as necessary.

Furthermore, the polyester film used in the present invention is preferably a microvoid-containing polyester film having an apparent density of 0.3 to 1.3 g/cm ³ . In addition, the cavity lamination number density is 0.20/μm or more, preferably 0.25/μm or more, and more preferably 0.30/μm or more, from the viewpoint of achieving both cushioning properties and surface peel strength. Certain microvoided polyester-based films are also preferred. As a result, the resulting polyester-based coating film is excellent in print sharpness and processability during printing. Here, the void lamination number density (pieces/μm) is defined by the formula: Number of voids in film thickness direction (pieces)/film thickness (μm). The upper limit of the cavity lamination number density is preferably 0.80/μm 2 , more preferably 0.55/μm, from the viewpoint of cavity generation efficiency. As a method to adjust the same density to the above range, in addition to adjusting the addition amount, type, viscosity, etc. of the incompatible thermoplastic resin, changing the screw shape of the extruder, and adding a static mixer to the molten resin flow path Although a method such as installation is used, it is not limited to this.

In these microvoid-containing polyester films, the microvoids contained in the film cause light scattering at the interface with the polyester matrix, thereby further improving the opacity and reducing the addition of the inorganic particles. , is particularly useful. Furthermore, by containing fine cavities, the weight of the base film itself can be reduced, so that handling is facilitated, and economic effects such as reduction in raw material costs and transportation costs are also large.

As a method for obtaining such a polyester film containing microvoids, the thermoplastic polyester resin as the matrix is kneaded with a thermoplastic resin incompatible with the polyester resin as described above, and the polyester resin is incompatible. A known method that has already been disclosed can be used, such as a method of generating cavities around the immiscible resin fine particles by stretching a sheet in which dissolved resin is dispersed in the form of fine particles at least uniaxially.

The thickness of the obtained polyester film substrate is preferably 5 to 300 μm. The thickness of the polyester film substrate is more preferably 20 to 300 μm, still more preferably 40 to 250 μm.

The preferred whiteness when used in printing materials and the like can be represented by the color b value. The higher the color b value, the stronger the yellowish color, and the lower the color b value, the stronger the bluish color. The color b value corresponds well to visual confirmation, and the color b value is preferably 4.0 or less, more preferably 3.0 or less. When the b value is 4.0 or less, the degree of whiteness is good, and when used as a label or the like, the clearness at the time of printing is excellent and the commercial value is increased, which is preferable. The lower limit of the color tone b value is preferably -5.0. When the b value is -5.0 or more, the bluish tint of the film does not become too strong, and the resolution can be well balanced when used as a printing base material, which is preferable.

(Description of characteristic values in the present invention)
The easily adhesive coating layer in the present invention preferably contains a cationic antistatic agent having a nitrogen element, a polyester resin, or a polyurethane resin. Then, the cationic antistatic agent component and the polyurethane resin component are present in a suitable amount and ratio on the surface of the easily adhesive coating layer, and the contact angle with water is controlled within a suitable range to avoid electrostatic failure in the printing process. In addition, it has good adhesion to various ink compositions. When stored in an environment, good adhesion to the ink layer is maintained without deterioration in adhesion.

Here, the amounts of the cationic antistatic agent component and the polyurethane resin component present on the surface of the easily adhesive coating layer are the ionized nitrogen element peak and the ionized nitrogen element peak in the N1s spectrum of X-ray photoelectron spectroscopy (ESCA), respectively. The peak area of each of the nitrogen element peaks is evaluated. In ESCA, the element species and chemical state corresponding to the peaks are identified from the peak positions of the obtained measured spectra. Further, curve fitting can be performed on the peaks of the elements to calculate the peak area. The easily adhesive coating layer in the present invention contains a cationic antistatic agent having a nitrogen element and a polyurethane resin. In the case of such an easily adhesive coating layer, the peaks of the ESCA N1s spectrum are exemplified in FIG. A thin solid line in the figure represents the measured data of the N1s spectrum. Of the two peaks, (1) the peak near 402 eV in the curve represented by the dotted line in the figure is the ionized nitrogen element peak, which can be determined to be derived from the cationic antistatic agent in the present invention. Furthermore, (2) the peak near 400 eV of the curve represented by the dashed line in the figure is the peak of non-ionized nitrogen element, which can be judged to be derived from the polyurethane resin in the present invention. Curve fitting is performed on the peaks of the spectra of all detected elements including the N1s spectrum, and when the total peak area is 100 (at%), the area ratio of (1) is calculated as the area ratio derived from the cationic antistatic agent. It is expressed as nitrogen element ratio A (at %) and used as an indicator of the abundance of the antistatic agent component on the surface of the easily adhesive coating layer. Similarly, the area ratio of (2) is expressed as the polyurethane resin-derived nitrogen element ratio B (at %), and is used as an indicator of the amount of the polyurethane resin component present on the surface of the easy-adhesive coating layer.

Then, for the easy-adhesive coating layer in the present invention, the characteristic values based on the surface element distribution measurement by ESCA satisfy the following relationships (i) and (ii), and the contact angle θ H ₂ of the easy-adhesive coating layer surface with respect to water When O is the following formula (iii), it avoids electrostatic failure in the printing process and has good adhesion to various ink compositions, especially active energy such as ultraviolet (UV) curable ink. As for the adhesion to the line-curable ink layer, good adhesion to the ink layer is maintained without deterioration in adhesion to the ink layer when stored in a high-temperature and high-humidity environment after printing.
(i) A (at%) > 0.4
(ii) 2.0 ≤ B/A ≤ 5.0
(iii) 50° _{≤θH2O≤70} °

ADVANTAGE OF THE INVENTION According to the present invention, there is provided a printed matter in which good adhesion is maintained without deterioration in adhesion between an ink layer and an easy-adhesion coating layer even when stored in a high-temperature and high-humidity environment after printing. be able to. As storage test conditions in a high-temperature and high-humidity environment in the present invention, the temperature and humidity exceed the normal temperature and humidity conditions defined in JIS-8703, and when used for labels for industrial electronic components, and in high-humidity environments such as Southeast Asia. Assuming that it will be used as a food label in Japan, the temperature was set at 80°C and the humidity was set at 90% RH for 3 days. In the adhesion evaluation described later, it is preferable that the remaining area of the printed layer before and after storage under the storage test conditions is 90% or more of the total, respectively, without deterioration of adhesion and adhesion. It is preferably within a range in which good adhesiveness and adhesion are maintained.

A description will be given of the principle of antistatic performance when using an ionic antistatic agent including a cationic antistatic agent in the present invention and the correlation with adhesion to ink. When an ionic antistatic agent is used to exhibit antistatic properties on the substrate surface, it is preferable to form a network of water on the substrate surface, which serves to conduct static electricity. The presence of the ionic antistatic agent on the substrate surface has the effect of attracting moisture in the air. Therefore, the larger the amount of the ionic antistatic agent present on the surface of the substrate, the easier it is to attract moisture in the air, and the easier it is to form a network of water, so that the antistatic property is more likely to be exhibited. On the other hand, however, as the abundance of the ionic antistatic agent on the base material surface increases, the abundance of the resin relatively decreases. That is, in the present invention, the amount of the polyurethane resin, which is generally considered to be related to the adhesion to the ink, may decrease, resulting in a decrease in the adhesion. Therefore, it is preferable to control the amounts of the ionic antistatic agent and the resin (especially the polyurethane resin) present on the surface of the easy-adhesive coating layer within a suitable range. In order to form a network of water even when the amount of the ionic antistatic agent present on the surface of the easy-adhesive coating layer is small, it is preferable to control the contact angle of the easy-adhesive coating layer surface to water. By controlling the contact angle of the easy-adhesion coating layer surface to a suitable range, moisture attracted by the antistatic agent on the surface of the easy-adhesion coating layer can wet and spread even in areas where the antistatic agent does not exist. becomes. In other words, by controlling the contact angle on the surface of the easy-adhesive coating layer, it is possible to assist the water network formation. Therefore, good antistatic properties can be obtained even with a smaller amount of antistatic agent. By obtaining the effect of assisting the formation of a network of water, excessive wetting and spreading of water is suppressed, so that the contact state between the ink and the polyurethane resin component on the surface of the easy-adhesive coating layer is in a suitable state. In addition, by controlling the contact angle of the surface of the easy-adhesive coating layer to a suitable range, the affinity with various inks as a printed matter is enhanced, the adhesion with the ink and the wet spreadability are improved, and the high-temperature and high-humidity When stored in an environment, it is possible to suppress deterioration of the easily adhesive coating layer due to moisture permeating the ink layer, and it is possible to maintain the adhesion.

A (at%) preferably exceeds 0.4. By controlling it within the above range, it becomes possible to attract moisture in the air to the surface of the coating film. By controlling the water contact angle of the easy-adhesive coating layer surface, which will be described later, within a suitable range, good antistatic properties can be obtained, and it is possible to avoid electrostatic failure in the printing process. A (at%) is more preferably 0.5 at% or more, and still more preferably 0.6 at% or more. However, if A (at %) is too large, it becomes difficult to satisfy the preferred range of B/A below, so it is preferably 5 at % or less, more preferably 3 at % or less, and even more preferably 2 at % or less.

B/A is preferably 2.0 to 5.0. By controlling B/A within the above range and controlling the contact angle of the coating film surface to water, which will be described later, within a suitable range, both antistatic properties and adhesion to ink can be achieved. In addition, even when the printed matter is stored in a high-temperature and high-humidity environment, deterioration of the coating film can be suppressed and good adhesion can be maintained. The lower limit of B/A is more preferably 3.0 or more. On the other hand, the upper limit of B/A is more preferably 4.0 or less.

The contact angle of the coating film surface to water is preferably in the range of 50° to 70°. The lower limit of the contact angle of the coating film surface to water is more preferably 60° or more. On the other hand, the upper limit of the contact angle of the coating film surface to water is more preferably 68° or less. By controlling the angle in the range of 50° to 70°, a good assisting effect can be obtained for network formation of water on the surface of the coating film. In addition, as a printed matter, the affinity with various inks is increased, the adhesion with ink and the wet spread are improved, and when stored in a high-temperature and high-humidity environment, the coating layer is easily adhered by moisture permeating the ink layer. deterioration can be suppressed, and adhesion can be maintained.

(Easy-adhesive coating layer)
The easy-adhesive polyester film in the present invention has both antistatic property and adhesion to ink and toner, and in order to obtain good adhesion to UV curable ink especially during high-speed printing, It is preferable that at least one surface thereof is provided with an easily adhesive coating layer composed of a cationic antistatic agent having a nitrogen element, a polyester resin, or a polyurethane resin. The easy-adhesive coating layer may be provided on both sides of the polyester film, or may be provided on only one side of the polyester film and a different resin coating layer may be provided on the other side.

Each composition of the easily adhesive coating layer will be described in detail below.
(Cationic antistatic agent)
Cationic antistatic agents include polyethyleneimine, polydimethyldiallylammonium salt, polyalkylenepolyamine dicyanodiamide ammonium condensate, polyvinylpyridium halide, alkyl quaternary ammonium (meth)acrylate, and alkyl quaternary ammonium (meth)acrylamido. salt, ω-chloro-poly(oxyethylene-polymethylene-alkyl quaternary ammonium salt), polyvinylbenzyltrimethylammonium salt, polystyrene cationic polymer, poly(meth)acrylic cationic polymer (methyl methacrylate, ethyl acrylate, 2- hydroxyethyl methacrylate, trimethylaminoethyl chloride methacrylate, etc.), polyvinylpyridine-based polymers, cyclic integral type polymers, linear integral type polymers, aromatic vinyl monomers having two or more pendant quaternary ammonium ion groups A polymer, a polymer having a pyrrolidium ring in the main chain, and the like are included. These polymers may be homopolymers or copolymers. Known copolymerizable monomers can be used to produce these polymers. In order to control the amount of the antistatic agent component present on the surface of the easily adhesive coating layer, it is preferably an antistatic agent having a linear alkyl group, and further has a linear alkyl group and a quaternary ammonium base It is preferably an antistatic agent having

In the present invention, the antistatic agent is preferably present on the surface of the easily adhesive coating layer.

Therefore, in the antistatic agent having a linear alkyl group and a quaternary ammonium base, the number of carbon atoms in the alkyl chain is preferably 10 to 20, more preferably 12 to 19, 14 to 18 are particularly preferred. In order to control the nitrogen element ratio derived from the cationic antistatic agent having a nitrogen element based on the surface element distribution measurement by ESCA to a suitable range, it is possible to bleed out the antistatic agent on the surface of the easily adhesive coating layer. The above range is preferable in view of the interaction between the same molecules and the easiness of bleeding out due to the molecular length.

In addition, in the molecular structure of the cationic antistatic agent having a nitrogen element, at least one amide bond or urethane bond may be included between the linear alkyl chain and the quaternary ammonium base.

In the above antistatic agent, the counter ion of the quaternary ammonium base is not particularly limited as long as it is an anionic compound, but is preferably halogen ion, mono- or polyhalogenated alkyl ion, nitrate ion, sulfate ion. , an alkylsulfate ion, a sulfonate ion, or an alkylsulfonate ion, preferably a chroyl ion, a methasulfonate ion, an ethanesulfonate ion, or a nitrate ion.

(polyester resin)
The polyester resin used for forming the easy-adhesive coating layer in the present invention may be a linear one, but more preferably a polyester resin having a dicarboxylic acid and a diol having a branched structure as its constituent components. Preferably. The dicarboxylic acid referred to here is mainly composed of terephthalic acid, isophthalic acid or 2,6-naphthalenedicarboxylic acid, as well as aliphatic dicarboxylic acids such as adipic acid and sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, 2, Aromatic dicarboxylic acids such as 6-naphthalenedicarboxylic acid are included. A branched glycol is a diol having a branched alkyl group, such as 2,2-dimethyl-1,3-propanediol, 2-methyl-2-ethyl-1,3-propanediol, 2- Methyl-2-butyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-2-isopropyl-1,3-propanediol, 2-methyl-2-n -hexyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-n-butyl-1,3-propanediol, 2-ethyl-2-n-hexyl- 1,3-propanediol, 2,2-di-n-butyl-1,3-propanediol, 2-n-butyl-2-propyl-1,3-propanediol, and 2,2-di-n- and hexyl-1,3-propanediol.

　Terephthalic acid or isophthalic acid is preferable as the dicarboxylic acid as a component of the polyester resin. In addition to the above dicarboxylic acid, it is preferable to copolymerize 5-sulfoisophthalic acid or the like in the range of 1 to 10 mol% in order to impart water dispersibility to the copolymerized polyester resin. 5-sulfoisophthalic acid, 5-sodiumsulfoisophthalic acid and the like can be mentioned. A polyester resin containing a dicarboxylic acid having a naphthalene skeleton may be used, but the quantitative ratio thereof should be 5 mol% or less in the total carboxylic acid component in order to suppress deterioration of adhesion to curable ink. It is preferable to have it, and it is not necessary to use it.

As a constituent component of the polyester resin, triol or tricarboxylic acid may be included to the extent that the properties of the polyester resin are not impaired.

The polyester resin may contain polar groups other than carboxyl groups. For example, sulfonic acid metal bases, phosphoric acid groups, and the like can be mentioned, and one or more of these can be used. As a method for introducing a sulfonic acid metal base, a metal salt such as 5-sulfoisophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5-[4-sulfophenoxy]isophthalic acid, or 2-sulfo-1, Dicarboxylic acids or glycols containing sulfonic acid metal bases such as metal salts such as 4-butanediol and 2,5-dimethyl-3-sulfo-2,5-hexanediol are added to 10 of the total polycarboxylic acid component or polyol component. A method of using it in the range of mol % or less, preferably 7 mol % or less, more preferably 5 mol % or less is mentioned. When it is 10 mol % or less, the hydrolysis resistance of the resin itself and the water resistance of the coating film are good, which is preferable.

(polyurethane resin)
In the present invention, the antistatic agent is present on the surface of the easy-adhesive coating layer, the characteristic values based on the surface element distribution measurement by ESCA satisfy a suitable relationship, and the contact angle of the easy-adhesive coating layer surface to water is suitable. range. Therefore, it is preferable to mainly control the polarity of the polyurethane resin.

Examples of methods for controlling the polarity of polyurethane resins include controlling the structure of the polyol component used in the synthesis and polymerization of polyurethane resins. In general, the polarity of ester skeletons and carbonate skeletons tends to be lower than that of ether skeletons. If the nitrogen element ratio derived from the cationic antistatic agent based on the surface element distribution measurement by ESCA is less than the suitable range, reduce the interaction between the polyurethane resin and the cationic antistatic agent and remove the antistatic agent. is present on the surface of the easily adhesive coating layer, it is preferable to use a polyurethane resin in which the skeleton of the polyol component used in the synthesis and polymerization of the polyurethane resin is an ester skeleton or a carbonate skeleton. It is particularly preferable to use a polyurethane resin having a carbonate skeleton.

　Ether skeleton polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, and the like.

Ester skeleton polyols include polyvalent carboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their acid anhydrides. substances and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol , 2-methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2 ,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2 -hexyl-1,3-propanediol, cyclohexanediol, bishydroxymethylcyclohexane, dimethanolbenzene, bishydroxyethoxybenzene, alkyldialkanolamine, lactonediol, etc.).

The carbonate skeleton polyol preferably contains an aliphatic polycarbonate polyol that is excellent in heat resistance and hydrolysis resistance. Aliphatic polycarbonate polyols include aliphatic polycarbonate diols and aliphatic polycarbonate triols, and aliphatic polycarbonate diols can be preferably used. Aliphatic polycarbonate diols used for synthesizing and polymerizing the polyurethane resin having a polycarbonate structure in the present invention include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5 - diols such as pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 1,8-nonanediol, neopentyl glycol, diethylene glycol and dipropylene glycol; Aliphatic polycarbonate diols obtained by reacting one or more of them with carbonates such as dimethyl carbonate, ethylene carbonate, and phosgene.

Another method for controlling the polarity of polyurethane resins is, for example, controlling the number average molecular weight of the polyol component used in the synthesis and polymerization of polyurethane resins. In general, when the number average molecular weight of the polyol component used in the synthesis and polymerization of polyurethane resin is large, the polarity of the polyurethane resin tends to be low. trend. When the contact angle of water on the surface of the easy-adhesive coating layer is less than the preferred range, it is preferable to increase the number-average molecular weight of the polyol component and decrease the polarity of the polyurethane resin. Further, when the contact angle of the easily adhesive coating layer surface to water exceeds a suitable range, it is preferable to decrease the number average molecular weight of the polyol component and increase the polarity of the polyurethane resin. As an example of the number average molecular weight, when the polyol used for the synthesis and polymerization of the polyurethane resin is an ester skeleton polyol, the number average molecular weight is preferably 1,000 to 2,400. More preferably 1200-2200, particularly preferably 1400-2200. In the case of a carbonate skeleton polyol, the number average content is preferably 500-1800. More preferably 600-1600, particularly preferably 700-1400.

A method for controlling the polarity of polyurethane resins is, for example, controlling the amount of urethane groups in the molecule. In general, when there are many urethane groups in the molecule, the polarity of the polyurethane resin tends to be high, and the amount of the polyurethane resin component present on the surface of the easy-adhesive coating layer tends to increase. On the other hand, when the number of urethane groups in the molecule is small, the polarity of the polyurethane resin tends to be low, and the amount of the polyurethane resin component present on the surface of the easy-adhesive coating layer tends to decrease. Therefore, by controlling the amount of urethane groups in the molecule, the abundance of the antistatic agent component on the surface of the easy-adhesive coating layer, the abundance of the polyurethane resin component, and the contact angle of water on the surface of the easy-adhesive coating layer can be reduced. change in parallel. Examples of the characteristic values based on the surface element distribution measurement by ESCA in the present invention and the contact angle to water on the surface of the easy-adhesive coating layer in a suitable range include the amount of urethane groups in the molecule (synthesis of polyurethane resin, The number average molecular weight of the isocyanate component/the number average molecular weight of the polyurethane resin used for polymerization) is preferably 26-38. More preferably 26-36.

A known method can be applied as a method for producing a polyurethane resin in the present invention. For example, a prepolymer having an isocyanate terminal is synthesized from a polyol and excess polyisocyanate, and then this prepolymer is added with a chain extender or a crosslinker. There is a method of reacting with to increase the molecular weight.

Examples of the polyisocyanate used for the synthesis and polymerization of the polyurethane resin in the present invention include aromatic-aliphatic diisocyanates such as xylylene diisocyanate, isophorone diisocyanate and 4,4-dicyclohexylmethane diisocyanate, and 1,3-bis(isocyanatomethyl). Alicyclic diisocyanates such as cyclohexane, hexamethylene diisocyanate, and aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate, or a single or multiple of these compounds previously added with trimethylolpropane or the like Polyisocyanates can be mentioned. When the above aromatic-aliphatic diisocyanates, alicyclic diisocyanates, or aliphatic diisocyanates are used, there is no problem of yellowing, which is preferable. In addition, the coating film is not too hard, the stress due to heat shrinkage of the polyester film substrate can be relieved, and there is no problem such as cohesive failure of the easily adhesive coating layer, which is preferable.

Examples of the chain extender used for the synthesis and polymerization of the polyurethane resin in the present invention include glycols such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol and 1,6-hexanediol, glycerin, and trimethylol. Polyhydric alcohols such as propane and pentaerythritol, diamines such as ethylenediamine, hexamethylenediamine, and piperazine, amino alcohols such as monoethanolamine and diethanolamine, thiodiglycols such as thiodiethylene glycol, or water. mentioned.

The easily adhesive coating layer in the present invention is preferably provided by an in-line coating method, which will be described later, using a water-based coating liquid. Therefore, it is desirable that the polyurethane resin in the present invention has water solubility or water dispersibility. The term "water-soluble or water-dispersible" means dispersing in water or an aqueous solution containing less than 50% by mass of a water-soluble organic solvent.

In order to impart water dispersibility to the polyurethane resin, a sulfonic acid (salt) group or a carboxylic acid (salt) group can be introduced (copolymerized) into the urethane molecular skeleton. The polyurethane resin into which a nonionic group such as a polyoxyalkylene group is introduced is particularly preferable because it can minimize the interaction between the polyurethane resin and the cationic antistatic agent.

The method of introducing the nonionic group can be appropriately selected from known methods. For example, a method of replacing part of the polymer polyol with a diol containing a polyoxyethylene group, or A method of reacting part of the isocyanate groups in the nurate form of diisocyanate with methoxypolyethylene glycol in advance and then reacting it with a high-molecular-weight polyol can be mentioned.

In order to introduce a carboxylic acid (salt) group into the polyurethane resin of the present invention, for example, a polyol compound having a carboxylic acid group such as dimethylolpropanoic acid or dimethylolbutanoic acid is introduced as a copolymerization component. , neutralized with a salt-forming agent. Specific examples of salt-forming agents include ammonia, trialkylamines such as trimethylamine, triethylamine, triisopropylamine, tri-n-propylamine and tri-n-butylamine; -N-dialkylalkanolamines such as alkylmorpholines, N-dimethylethanolamine and N-diethylethanolamine. These can be used alone or in combination of two or more.

When a polyol compound having a carboxylic acid (salt) group is used as a copolymerization component in order to impart water dispersibility, the composition molar ratio of the polyol compound having a carboxylic acid (salt) group in the polyurethane resin is When the total polyisocyanate component of is 100 mol%, it is preferably 3 to 25 mol%, more preferably 3 to 18 mol%, and particularly preferably in the range of 3 to 15 mol%. . By controlling it within the above range, interaction with the coexisting cationic antistatic agent component is suppressed while ensuring water dispersibility, and the antistatic agent can be present on the surface of the easily adhesive coating layer. becomes.

The polyurethane resin in the present invention may be a self-crosslinking polyurethane resin with blocked isocyanate bound to the end to improve toughness.

The polyurethane resin in the present invention may have a branched structure.

In order to form a branched structure in the polyurethane resin, for example, the polycarbonate polyol component, polyisocyanate, and chain extender are allowed to react at an appropriate temperature and time, and then tri- or more functional hydroxyl groups or isocyanate groups are added. A method of adding a compound having a compound and further advancing the reaction can be preferably employed.

Specific examples of compounds having a trifunctional or higher hydroxyl group include caprolactone triol, glycerol, trimethylolpropane, butanetriol, hexanetriol, 1,2,3-hexanetriol, 1,2,3-pentanetriol, 1,3 ,4-hexanetriol, 1,3,4-pentanetriol, 1,3,5-hexanetriol, 1,3,5-pentanetriol and polyethertriol. Examples of the polyether triols include, for example, glycerin, alcohols such as trimethylolpropane, diethylenetriamine, and the like, using one or more compounds having three active hydrogens as initiators, ethylene oxide, propylene oxide, and butylene. Compounds obtained by addition polymerization of one or more of monomers such as oxides, amylene oxides, glycidyl ethers, methyl glycidyl ethers, t-butyl glycidyl ethers, and phenyl glycidyl ethers can be mentioned.

A specific example of the compound having a trifunctional or higher isocyanate group is a polyisocyanate compound having at least three or more isocyanate (NCO) groups in one molecule. In the present invention, trifunctional or higher isocyanate compounds are aromatic diisocyanates, aliphatic diisocyanates, araliphatic diisocyanates, alicyclic diisocyanates having two isocyanate groups. and adducts. Aromatic diisocyanates include, for example, 1,3-phenylene diisocyanate, 4,4′-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate isocyanate, 4,4'-toluidine diisocyanate, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and the like. Aliphatic diisocyanates are, for example, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2, 4,4-trimethylhexamethylene diisocyanate and the like. Examples of araliphatic diisocyanates include xylylene diisocyanate, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,4-tetramethylxylylene diisocyanate, and 1,3-tetramethylxylylene diisocyanate. Alicyclic diisocyanates include, for example, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (also known as IPDI, isophorone diisocyanate), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, 4,4'-methylenebis(cyclohexylisocyanate), 1,4-bis(isocyanatomethyl)cyclohexane, and the like. The burette body is a self-condensed product having a burette bond formed by self-condensation of an isocyanate monomer, and examples thereof include a burette body of hexamethylene diisocyanate. A nurate compound is a trimer of an isocyanate monomer, and examples thereof include a trimer of hexamethylene diisocyanate, a trimer of isophorone diisocyanate, a trimer of tolylene diisocyanate, and the like. The adduct refers to a tri- or higher functional isocyanate compound obtained by reacting the above isocyanate monomer with a tri- or higher-functional low-molecular-weight active hydrogen-containing compound, for example, a compound obtained by reacting trimethylolpropane and hexamethylene diisocyanate. , a compound obtained by reacting trimethylolpropane and tolylene diisocyanate, a compound obtained by reacting trimethylolpropane and xylylene diisocyanate, a compound obtained by reacting trimethylolpropane and isophorone diisocyanate, and the like.

Examples of chain extenders having a number of functional groups of 3 or more include trimethylolpropane and alcohols having a hydroxy group of 3 or more functional groups, such as pentaerythritol, which are described in the above description of chain extenders.

(ratio)
In the present invention, the antistatic agent is present on the surface of the easy-adhesive coating layer, the characteristic values based on the surface element distribution measurement by ESCA satisfy a suitable relationship, and the contact angle of the easy-adhesive coating layer surface to water is suitable. range. Therefore, after mainly controlling the polarity of the polyurethane resin, the solid content ratio of each component with respect to the total solid content of the cationic antistatic agent, polyester resin, and polyurethane resin is adjusted to provide an easy-adhesive coating layer. It is preferable to control the polarity as

When the total solid content of the cationic antistatic agent, polyester resin, and polyurethane resin in the coating liquid is 100% by mass, the content (% by mass) of the cationic antistatic agent is 3.5 to 7.0. is preferred, and 4.0 to 5.5 is more preferred. By setting the above range, the nitrogen element ratio derived from the cationic antistatic agent having a nitrogen element based on the surface element distribution measurement by ESCA, and the nitrogen element ratio derived from the polyurethane resin / the nitrogen element ratio derived from the cationic antistatic agent It can be controlled within a suitable range.

When the total solid content of the cationic antistatic agent, polyester resin, and polyurethane resin in the coating liquid is 100% by mass, the polyester resin content (% by mass) is preferably 25 to 80, preferably 30 to 80. is more preferable. Furthermore, 35 to 80 is particularly preferred. By adjusting the above range, the adhesiveness between the easily adhesive coating layer and the polyester film substrate is ensured, and the polar groups in the polyester resin that can interact with the coexisting cationic antistatic agent component, such as carboxyl group and sulfone. The amount of acid metal base and phosphate group is controlled, and the nitrogen element ratio derived from the cationic antistatic agent having nitrogen element based on surface element distribution measurement by ESCA can be controlled within a suitable range.

When the total solid content of the cationic antistatic agent, polyester resin, and polyurethane resin in the coating liquid is 100% by mass, the polyurethane resin content (% by mass) is preferably 15 to 65, more preferably 20 to 55. is more preferable. When the content of polyurethane resin is low, the ratio of polyester resin is relatively high, and the amount of polar groups such as carboxyl groups, sulfonic acid metal groups, and phosphoric acid groups in the polyester resin in the easy-adhesion coating layer increases. It will be. If the content of the polyurethane resin is high, the polarity of the easy-adhesive coating layer will be low. While the polyurethane component on the surface of the easy-adhesion coating layer increases, the polarity of the easy-adhesion coating layer is low, so the cationic antistatic agent tends to exist on the surface of the easy-adhesion coating layer. In other words, the amount of the cationic antistatic agent component on the surface of the easy-adhesive coating layer also increases. In view of them, by setting the content rate (% by mass) of the polyurethane resin in the above range, the nitrogen element ratio derived from the cationic antistatic agent having nitrogen element based on the surface element distribution measurement by ESCA, and the polyurethane resin-derived nitrogen element ratio The nitrogen element ratio/the nitrogen element ratio derived from the cationic antistatic agent can be controlled within a suitable range.

(Additive)
Known additives such as surfactants, antioxidants, heat stabilizers, weather stabilizers, ultraviolet absorbers, and organic facilitators may be added to the easily adhesive coating layer in the present invention as long as they do not impair the effects of the present invention. Lubricants, pigments, dyes, organic or inorganic particles, nucleating agents, etc. may be added.

Inert particles may be contained in the easily adhesive coating layer in order to reduce the glossiness of the easily adhesive coating layer surface.

Examples of the inert particles include titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silica, alumina, talc, kaolin, clay, calcium phosphate, mica, hectorite, zirconia, tungsten oxide, lithium fluoride, and fluoride. Examples include inorganic particles such as calcium, and organic polymer particles such as polystyrene, polyacrylic, melamine, benzoguanamine, and silicone resins. These may be used alone or in combination of two or more.

The average particle diameter of the inert particles is preferably 0.1-2.4 μm, more preferably 0.3-2.0 μm. When the average particle size of the inert particles is 0.1 μm or more, the glossiness of the film surface does not become too high, which is preferable. Conversely, if the particle size is 2.4 μm or less, the particles are less likely to fall off from the easily adhesive coating layer, and powder fall-off can be prevented, which is preferable.

The content of the inert particles can be added within a range that does not impair the effects of the present invention. The content of the solid content of the particles is preferably 0 to 70.0% by mass, preferably 0 to 60.0% by mass, more preferably 0 to 60.0% by mass, based on the total solid content of the easy-adhesive coating layer. It is preferably ~55.0% by mass.

The shape of the particles is not particularly limited as long as it satisfies the object of the present invention, and spherical particles and irregularly shaped non-spherical particles can be used. The particle diameter of amorphous particles can be calculated as the equivalent circle diameter.

In order to increase the glossiness of the easy-adhesion coating layer, it is better not to include particles in the easy-adhesion coating layer.

(Polyester film manufacturing method)
The method for producing the polyester film in the present invention is arbitrary and not particularly limited, but it can be produced, for example, as follows.

After sufficiently vacuum-drying the film raw material, it is melted in an extruder and extruded into a sheet form from a T-die while applying static electricity to a rotating cooling metal roll to obtain an unstretched film.

At this time, the white pigment and other additives are not powdered and kneaded in the extruder, but a masterbatch polymer is prepared by separately containing the white pigment and the like in the polyester resin at a high concentration in advance. is preferably blended and diluted with a polyester resin from the viewpoint of uniform mixing. It is preferable to use a twin-screw extruder in order to sufficiently and uniformly mix the various film raw materials. Further, it is preferable to add an alkaline earth metal salt and/or an alkali metal salt and phosphoric acid or a salt thereof when polymerizing the polyester in order to improve the electrostatic adhesion. Addition of phosphoric acid or a salt thereof also has the effect of improving color tone (particularly b value).

In the present invention, the base polyester film may have a single-layer structure or a laminated structure. The laminate structure has the advantage that the compositions of the surface layer and the central layer can be designed in various ways according to the required functions. When the polyester film of the base material has a laminated structure, after supplying the resins of the X layer and the Y layer to separate extruders, for example, a two-layer structure of the X layer / Y layer in a molten state, the X layer It is most preferable to adopt a co-extrusion method in which a three-layer structure such as /Y layer/X layer is laminated and extruded from the same die.

The unstretched film obtained in this way is further stretched between rolls with a speed difference (roll stretching), stretched by gripping and spreading with clips (tenter stretching), or stretched by spreading with air pressure (inflation stretching). ) or the like.

The conditions for stretching and orienting an unstretched film are closely related to the physical properties of the film. The stretching and orientation conditions will be described below by taking as an example the most common sequential biaxial stretching method, particularly a method in which an unstretched sheet is stretched in the longitudinal direction and then in the width direction.

First, in the first longitudinal stretching step, the film is stretched between two or multiple rolls with different peripheral speeds. As a heating means at this time, a method using a heating roll or a method using a non-contact heating method may be used, or both of them may be used. Then, the uniaxially stretched film is introduced into a tenter and stretched 2.5 to 5 times in the width direction at a temperature not higher than the melting point Tm-10° C. of the polyester.

The biaxially stretched film thus obtained is subjected to heat treatment as necessary. The heat treatment is preferably carried out in a tenter, and the heat treatment temperature is preferably in the range from the melting point (Tm) of polyester -50 (°C) to Tm (°C).

(Cavity-containing PET manufacturing method)
The polyester film substrate in the present invention may be obtained by dispersing a thermoplastic resin incompatible with the polyester resin in the polyester resin in the process of melting and extruding the film raw material. The polyester film substrate in the present invention is also preferably a white polyester film substrate. In the experimental examples of the present invention, the polyester resin and the thermoplastic resin incompatible with the polyester resin were supplied in the form of pellets, but the present invention is not limited to this.

The raw materials to be fed into the extruder for melt molding into a film are prepared by mixing these resin pellets according to the desired composition. As a suitable method for preventing the segregation of the polyester film substrate in the present invention, there is a method in which part or all of the raw material resins are previously combined, kneaded and pelletized to form a masterbatch pellet. Although this method was used in the experimental examples of the present invention, it is not particularly limited as long as it does not interfere with the effects of the present invention.

In addition, in the extrusion of a mixed system of these incompatible resins, even after mixing and finely dispersing them in a molten state, they have the property of reaggregating due to the action of reducing the interfacial energy of the resin. This is a phenomenon in which the void forming agent is coarsely dispersed during the extrusion molding of the unstretched film and hinders the development of desired physical properties.

In order to prevent this, when forming the film in the present invention, it is preferable to finely disperse the cavity forming agent in advance using a twin-screw extruder with a higher mixing effect. Moreover, when this is difficult, as an auxiliary means, it is also preferable to feed the starting resin from the extruder through a static mixer to a feed block or a die. As the static mixer used here, a static mixer, an orifice, or the like can be used. However, when these methods are employed, it is preferable not to allow the heat-degraded resin to stagnate in the melt line.

In addition, the thermoplastic resin that is incompatible with the polyester once dispersed in the form of fine particles in the polyester resin tends to reaggregate with time under a low-shear molten state, so extrusion A fundamental solution is to reduce the residence time in the melt line from the machine to the die. In the present invention, the residence time in the melt line is preferably 30 minutes or less, more preferably 15 minutes or less.

The conditions for stretching and orienting the unstretched film obtained as described above are closely related to the physical properties of the film. Hereinafter, the stretching and orientation conditions will be described by taking as an example the most common sequential biaxial stretching method, particularly a method in which an unstretched film is stretched in the longitudinal direction and then in the width direction.

In the longitudinal stretching step, the film is stretched 2.5 to 5.0 times in the longitudinal direction with rolls heated to 80 to 120°C to obtain a uniaxially stretched film. As a heating means, a method using a heating roll or a method using a non-contact heating method may be used, or they may be used in combination. Then, the uniaxially stretched film is introduced into a tenter and stretched 2.5 to 5 times in the width direction at a temperature of (Tm-10°C) or less. However, Tm means the melting point of polyester.

In addition, the above biaxially stretched film is subjected to heat treatment as necessary. The heat treatment is preferably carried out in a tenter, preferably in the range of (Tm-60°C) to Tm.

(Preparation when using recycled polyester raw materials)
The polyester-based resin in the present invention may contain a polyester-based resin recycled from PET bottles. Crystallinity is controlled for the polyester used in PET bottles in order to improve bottle moldability and appearance. In some cases, those containing 10.0 mol % or less of an isophthalic acid component and an ester constitutional unit derived from an arbitrary diol component represented by ethylene glycol or diethylene glycol are used. In some cases, a polyester obtained by further performing solid-phase polymerization after liquid-phase polymerization to increase the intrinsic viscosity is used. Polyester-based resin pellets recycled from PET bottles are usually made by washing, pulverizing, heating and melting the PET bottles and re-pelletizing them. I don't mind. The intrinsic viscosity of the polyester resin recycled from PET bottles is preferably in the range of 0.60 to 0.75 dl/g. When the intrinsic viscosity is 0.60 dl/g or more, the resulting film is less likely to break, and film production can be stably operated, which is preferable. On the other hand, when the intrinsic viscosity is 0.75 dl/g or less, the filtration pressure of the molten fluid does not increase too much, and the film production can be stably operated, which is preferable. In general, when a polyethylene terephthalate resin is polymerized in a solid phase, the amount of oligomers contained in the resin, especially the PET cyclic trimer, which is the most abundant, is smaller than that in a liquid phase polymerized product. The upper limit of the cyclic trimer oligomer contained in the recycled polyester resin made from PET bottles is preferably 0.7% by mass, more preferably 0.5% by mass, and more preferably 0.4% by mass. is.

The lower limit of the content of polyester resin recycled from PET bottles to the void-containing polyester film is preferably 25% by mass, more preferably 30% by mass, and even more preferably 50% by mass. When it is 25% by mass or more, the amount of oligomer contained in the void-containing polyester-based film is reduced, and precipitation of the oligomer can be suppressed, which is preferable. Furthermore, in terms of utilization of recycled resin, a high content is preferable from the viewpoint of contributing to reduction of environmental load. The upper limit of the content of polyester resin recycled from PET bottles is preferably 90% by mass, more preferably 85% by mass.

The easily adhesive coating layer can be provided after the film is manufactured or during the manufacturing process. In particular, from the viewpoint of productivity, it is preferable to apply a coating liquid to at least one side of an unstretched or uniaxially stretched PET film to form an easily adhesive coating layer at any stage of the film manufacturing process.

Any known method can be used to apply this coating liquid to the PET film. For example, reverse roll coating method, gravure coating method, kiss coating method, die coater method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, impregnation coating method, curtain coating method, etc. be done. These methods can be applied singly or in combination.

As for the drying conditions after coating, the cationic antistatic agent component bleeds out on the surface of the easily adhesive coating layer, and the characteristic values based on the surface element distribution measurement by ESCA satisfy a suitable relationship. 150°C, more preferably 90°C to 140°C. A range of 100° C. to 130° C. is particularly preferred. However, by lengthening the drying time, it is possible to bleed out the cationic antistatic agent component to the surface of the easy-adhesive coating layer even at relatively low temperatures. satisfies a suitable relationship, so the above conditions are not limited.

In the present invention, the thickness of the easily adhesive coating layer is preferably in the range of 50-900 nm, more preferably in the range of 70-800 nm, still more preferably in the range of 100-600 nm, and particularly preferably in the range of 200-500 nm. As the thickness of the easy-adhesion coating layer increases, the amount of the cationic antistatic agent component present per volume of the easy-adhesion coating layer increases. In other words, when they bleed out to the surface of the easy-adhesion coating layer, a large amount of the cationic antistatic agent component is present on the surface of the easy-adhesion coating layer. On the other hand, since the thickness of the easily adhesive coating layer is reduced, the amount of the intervening cationic antistatic agent component per volume of the easily adhesive coating layer is reduced. In other words, the cationic antistatic agent component present on the surface of the easy-adhesive coating layer is reduced. Therefore, by controlling the thickness of the easy-adhesive coating layer within the above range, the nitrogen element ratio derived from the cationic antistatic agent and the nitrogen element ratio derived from the polyurethane resin / derived from the cationic antistatic agent can be obtained by measuring the surface element distribution by ESCA can be controlled within a suitable range.

(UV curable ink)
The UV curable ink in the present invention is a general term for inks that are cured by ultraviolet light. The composition of the ink includes pigments (dyes), oligomers and monomers, photopolymerization initiators and accelerators, auxiliary agents, and the like. Oligomers and monomers act as fluid components in this component, and after being spread on a printing material, are cured by radicals generated from a photopolymerization initiator by an ultraviolet lamp. The content ratio of oligomers and monomer species varies depending on the printing method described later. Basically, it does not contain a solvent except for the purpose of adjusting the viscosity, and even if it contains a solvent, it is preferably about 10% by mass at most.

(Solvent ink)
The solvent-based ink in the present invention is a general term for inks that are cured by evaporation drying. The composition of the ink is a pigment (dye), a resin component, a diluting solvent, an auxiliary agent, and the like. After printing, the solvent evaporates quickly, leaving resin and pigment on the surface to be printed, and the ink dries very quickly, making it suitable for high-speed, high-volume printing.

(Oxidative polymerization type ink)
The oxidative polymerization type ink in the present invention is mainly composed of a drying oil that is polymerized and hardened by oxygen in the air, and also contains a pigment (dye), a polymerization accelerator, an auxiliary agent, and the like. The drying oil acts as a fluid component, and the viscosity is adjusted according to the printing method. Recently, there is also a composite type containing both an ultraviolet curing component and a drying oil. Chill, ethyl acetate, ketones such as acetone, MEK, and the like, which may be used alone or in mixtures thereof and mixtures with alcohols. Organic solvents do not contain polymerizable/curable monomers, oligomers, or oils. Printing methods using these include flexographic printing, screen printing, and offset printing. The viscosity of the ink is set higher for the latter.

(thermal transfer ink)
The thermal transfer ink in the present invention is a hot-melt pigment ink, and is used in a thermal transfer method in which ink applied to an ink ribbon is melted by heat and transferred to paper for printing. As for the composition, the ink contains coloring agents such as pigments and dyes, binders such as waxes and thermoplastic resins, and various additives such as softeners and dispersants. Resin type or wax type ink is used for the thermal transfer method. Among them, the resin type is preferably used because of its excellent weather resistance. It is used for monochrome document output of word processors, tape writers, bar code printers, etc. It is also used in some color printers and video printers by using color ribbons.

(LBP toner)
The LBP toner in the present invention is a powder for coloring used in laser printers and copiers, and is a mixture of charged fine particles (polymer resin), wax, pigment, and the like. For color printing, four colors of blue-green, red-purple, yellow, and black are used. LBP is a page printer that charges a drum with laser light and uses static electricity to adhere toner.

Evaluation methods used in the present invention are described below.
(1) Measurement of Nitrogen Element (N and N ⁺ ) Ratio in Surface Region The surface composition was measured by ESCA. K-Alpha ⁺ (manufactured by Thermo Fisher Scientific) was used as an apparatus. Details of the measurement conditions are shown below. In the analysis, the background was removed by the Shirley method. In addition, the surface composition ratio is the average value of the measurement results of 3 or more locations, and N (N ⁺ isoionized nitrogen element) and N (non-ionized nitrogen element such as CN) are calculated by peak separation of the N1s spectrum. did. Here, N (N ⁺ isoionized nitrogen element) is the peak around 402 eV in the N1s spectrum, and N (Non-ionized nitrogen element such as CN) is the peak around 400 eV.
・Measurement conditions Excitation X-rays: Monochrome Al Kα rays X-ray output: 12 kV, 6 mA
Photoelectron escape angle: 90 °
Spot size: 400μmφ
Pass energy: 50eV
Step : 0.1eV
FIG. 1 is a graph showing analysis results of the N1s spectrum of the surface region of the substrate having the easily adhesive coating layer of Experimental Example 1. FIG. The thin solid line represents the measured data of the N1s spectrum. The peaks of the obtained measured spectrum were separated into a plurality of peaks, and the binding species corresponding to each peak were identified from the position and shape of each peak. Further, curve fitting was performed on the peaks derived from each binding species to calculate the peak area. The peak area of N (N ⁺ equiionized nitrogen element) was defined as A (at%), and the peak area of N (nonionized nitrogen element such as CN) was defined as B (at%).

(2) Measurement of contact angle with water After leaving the base material having an easy-adhesive coating layer in an atmosphere of 23 ° C. and 65% RH for 24 hours, a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., CA- X), using distilled water stored under the same conditions, the contact angle between the coating layer surface of the sample and water was measured. The measurement was performed at 10 points, and the average value thereof was used as contact angle data.

(3) Surface specific resistance value of easy-adhesive coating layer After leaving the substrate having the easy-adhesive coating layer in an atmosphere of 23 ° C. and 65% RH for 24 hours, a surface resistance value measuring device ( The surface resistivity (Ω/□) of the film surface (the surface of the coating layer, if provided) was measured at an applied voltage of 500 V using Hiresta-IP manufactured by Mitsubishi Yuka Co., Ltd.
Especially good when less than 1×10 ¹² Ω/□: ◎
1×10 ¹² Ω/□ or more to less than 1×10 ¹³ Ω/□ is good: ○,
1×10 ¹³ Ω/□ or more: x.

(4) Initial adhesion After producing the printed matter described in the experimental example described later, using Nichiban's cellophane adhesive tape (CT405AP-24), cut it into a width of 24 mm and a length of 50 mm, and between the ink layer of the printed matter and the tape. It was completely adhered with a handy rubber roller so as not to mix air. Thereafter, the adhesive cellophane tape was peeled off vertically, and the remaining area of the printed layer was observed in an area of 24 mm×50 mm, and judged according to the following criteria. In the present invention, 4 or more was regarded as passing.
5: The remaining area of the printed layer is 99% or more of the total 4: The remaining area of the printed layer is 90% or more and less than 99% of the total 3: The remaining area of the printed layer is 80% or more and less than 90% of the total 2: Printing The remaining area of the layer is 70% or more and less than 80% of the total 1: The remaining area of the printed layer is 60% or more and less than 70% of the total

(5) Adhesion after storage in a high-temperature high-environment The humidity was set to 90%, and the printed material was stored for 3 days under the above temperature and humidity conditions. After storage, the printed material was taken out and allowed to stand until normal temperature was reached. After allowing to stand still, using Nichiban's cellophane adhesive tape (CT405AP-24), it was cut into a width of 24 mm and a length of 50 mm. . Thereafter, the adhesive cellophane tape was peeled off vertically, and the remaining area of the printed layer was observed in an area of 24 mm×50 mm, and judged according to the following criteria. In the present invention, 4 or more was regarded as passing.
5: The remaining area of the printed layer is 99% or more of the total 4: The remaining area of the printed layer is 90% or more and less than 99% of the total 3: The remaining area of the printed layer is 80% or more and less than 90% of the total 2: Printing The remaining area of the layer is 70% or more and less than 80% of the total 1: The remaining area of the printed layer is 60% or more and less than 70% of the total

(7) Apparent Density Four 5.00 cm square films were cut out from the film and used as samples. Four sheets of this were stacked, and the thickness was measured using a thickness micrometer at 10 points with four significant digits to determine the average value of the stacked thickness. This average value was divided by 4, rounded off to the fourth decimal place, and the average film thickness per sheet (t: μm) was obtained to the third decimal place. Further, the mass (w:g) of four sheets of the same sample was measured by an automatic top pan balance to four significant digits, and the apparent density was determined by the following formula. Apparent densities were rounded to three significant digits.
Apparent density (g/cm ³ )=w×10 ⁴ /(5.00×5.00×t×4)

(8) Resin Solid Content Thickness of Adhesive Coating Layer The resin solid content thickness was calculated from the coating amount of the coating material and the total resin solid content mass contained in the coating material.

(9) b value In accordance with JIS-8722, the color b value of reflection was measured using a color difference meter (ZE6000, manufactured by Nippon Denshoku Industries Co., Ltd.).

Next, the present invention will be described in detail using experimental examples, but the present invention is not limited to the following experimental examples.

(Synthesis of cationic antistatic agent having nitrogen element: A-1)
Using 89 g of dimethylaminoethanol and 285 g of stearic acid having 18 carbon atoms, an esterification reaction was carried out at 100°C under a nitrogen atmosphere for 10 hours. It was put in and reacted at 70° C. for about 10 hours. After the reaction, the solvent was distilled off under reduced pressure, and isopropanol was added to adjust the solid content to a desired concentration, thereby obtaining an isopropanol solution A-1 of a cationic antistatic agent having a quaternary ammonium salt.

(Synthesis of cationic antistatic agent having nitrogen element A-2)
Using 116 g of N,N dimethyl-1,3-propanediamine and 285 g of stearic acid, the same treatment as in A-1 was carried out to obtain an isopropanol solution A- of a cationic antistatic agent having a quaternary ammonium salt. got 2.

(Polymerization of polyester resin B-1)
194.2 parts by weight of dimethyl terephthalate, 184.5 parts by weight of dimethyl isophthalate, 14.8 parts by weight of dimethyl-5-sodium sulfoisophthalate were added to a stainless steel autoclave equipped with an agitator, thermometer, and partial reflux condenser. , 233.5 parts by mass of diethylene glycol, 136.6 parts by mass of ethylene glycol, and 0.2 parts by mass of tetra-n-butyl titanate were charged, and transesterification was carried out at a temperature of 160° C. to 220° C. over 4 hours. Then, the temperature was raised to 255° C., the pressure of the reaction system was gradually reduced, and the reaction was allowed to proceed under a reduced pressure of 30 Pa for 1 hour and 30 minutes to obtain a copolymer polyester resin (B-1). The obtained copolymer polyester resin (B-1) was pale yellow and transparent. The reduced viscosity of the copolymer polyester resin (B-1) was measured and found to be 0.70 dl/g. The glass transition temperature by DSC was 40°C.

(Preparation of polyester aqueous dispersion Bw-1)
25 parts by mass of polyester resin (B-1) and 10 parts by mass of ethylene glycol n-butyl ether were placed in a reactor equipped with a stirrer, a thermometer and a reflux device, and the mixture was heated at 110° C. and stirred to dissolve the resin. After the resin was completely dissolved, 65 parts by mass of water was slowly added to the polyester solution with stirring. After the addition, the liquid was cooled to room temperature while stirring to prepare a milky white polyester aqueous dispersion (Bw-1) having a solid content of 30.0% by mass.

(Preparation of polyester resin solution Bw-2)
97 parts by mass of dimethyl terephthalate, 93 parts by mass of dimethyl isophthalate, 68 parts by mass of ethylene glycol, 116 parts by mass of diethylene glycol, 0.1 part by mass of zinc acetate and 0.1 part by mass of antimony trioxide were charged into a reaction vessel and heated at 180°C for 3 hours. The transesterification reaction was carried out over a period of time. Next, 7.1 parts by mass of 5-sodium sulfoisophthalic acid was added and an esterification reaction was carried out at 240°C over 1 hour, followed by 2 hours at 250°C under reduced pressure (1.33 to 0.027 kPa). A polycondensation reaction was carried out to obtain a polyester resin having a molecular weight of 22,000. 300 parts by mass of this polyester resin and 140 parts by mass of butyl cellosolve were stirred at 160° C. for 3 hours to obtain a viscous melt, and water was gradually added to the melt. % by weight polyester resin solution (Bw-2) was prepared.

(Preparation of Polyurethane Resin Solution C-1 Having a Polycarbonate Structure)
22 parts by weight of 4,4-dicyclohexylmethane diisocyanate and 20 parts by weight of polyethylene glycol monomethyl ether having a number average molecular weight of 700 were added to a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer. , 53 parts by weight of polyhexamethylene carbonate diol having a number average molecular weight of 2,100, 5 parts by weight of neopentyl glycol, and 84.00 parts by weight of acetone as a solvent were added and stirred at 75° C. for 3 hours under a nitrogen atmosphere to form a reaction solution. It was confirmed that the predetermined amine equivalent weight was reached. After that, the temperature of the reaction liquid was lowered to 50° C., and 3 parts by mass of methyl ethyl ketoxime was added dropwise. After cooling the reaction solution to 40° C., a polyurethane prepolymer solution was obtained. Next, 450 g of water was added to a reaction vessel equipped with a homodisper capable of high-speed stirring, the temperature was adjusted to 25° C., and the polyurethane prepolymer solution was added and dispersed in water while stirring and mixing at 2000 min ⁻¹ . . Thereafter, acetone and part of the water were removed under reduced pressure to prepare a water-dispersible polyurethane resin solution (C-1) having a solid content of 35.4% by mass.

(Preparation of Polyurethane Resin Solution C-2 Having a Polycarbonate Structure)
31.0 parts by mass of hydrogenated m-xylylenediisocyanate, 7.0 parts by mass of dimethylolpropanoic acid, 60 parts by mass of polyhexamethylene carbonate diol having a number average molecular weight of 1800, 6 parts by mass of neopentyl glycol, and 84.00 parts by mass of acetone as a solvent were added, and the mixture was stirred at 75° C. for 3 hours under a nitrogen atmosphere until the reaction mixture reached a predetermined level. was confirmed to have reached the amine equivalent weight of After cooling the reaction solution to 40° C., 6.65 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Next, 450 g of water was added to a reaction vessel equipped with a homodisper capable of high-speed stirring, the temperature was adjusted to 25° C., and the polyurethane prepolymer solution was added while stirring and mixing at 2000 min ⁻¹ . Water dispersed. Thereafter, acetone and part of the water were removed under reduced pressure to prepare a water-dispersible polyurethane resin solution (C-2) having a solid content of 35.0% by mass.

(Preparation of Polyurethane Resin Solution C-3 Having a Polyester Structure)
82.8 parts by mass of hydrogenated m-xylylenediisocyanate, 25.0 parts by mass of dimethylolpropanoic acid, 2 parts by mass of 3-methyl-1,5-pentanediol 150.0 parts by mass of polyester diol consisting of terephthalic acid/isophthalic acid//ethylene glycol/diethylene glycol = 50/50//40/60 (molar ratio), and as a solvent , 110 parts by mass of acetone was added, and the mixture was stirred at 75°C for 3 hours under a nitrogen atmosphere, and it was confirmed that the reaction solution reached a predetermined amine equivalent weight. Next, after the temperature of this reaction liquid was lowered to 40° C., 19.8 parts by mass of triethylamine was added to obtain a polyurethane polymer solution. Next, 880 g of water was added to a reactor equipped with a homodisper capable of high-speed stirring, adjusted to 25° C., and the polyurethane polymer solution was added and dispersed in water while stirring and mixing at 2000 min ⁻¹ . After that, the solvent, acetone, was removed under reduced pressure. A polyurethane resin solution (C-3) having a solid content of 30.0% by mass was prepared by adjusting the concentration with water.

(Preparation of polyurethane-blocked isocyanate aqueous dispersion (C-4) having a polyester structure)
33.6 parts by mass of hexamethylene diisocyanate was added to 200 parts by mass of a polyester (molecular weight: 2000) of an adduct of 2 mol of ethylene oxide of bisphenol A and maleic acid, and the reaction was carried out at 100° C. for 2 hours. Then, the temperature of the system is once lowered to 50° C., 73 parts by mass of a 30% sodium bisulfite aqueous solution is added, and after stirring at 45° C. for 60 minutes, the mixture is diluted with 718 parts by mass of water to obtain a solid content of 20.0% by mass. to obtain a blocked polyisocyanate aqueous dispersion (C-4). The number of functional groups of the blocked isocyanate crosslinking agent is 2, and the NCO equivalent is 1,300.

(Experimental example 1)
(1) Preparation of coating solution Mix the following coating agent with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution is 5.0. /57.0/38.0. In the manufacturing process of the white easily adhesive film, which will be described later, the coating was applied so that the thickness of the resin solid content was 450 nm.
Nitrogen-containing cationic antistatic agent solution (A-1) 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 17.00 parts by mass Polyurethane resin solution (C-1) 9.60 parts by mass Particles 25.15 parts by mass (silica particles with an average particle size of 0.45 μm, solid content concentration 40.00 mass%)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(2) Preparation of master pellet M1 60% by mass of polymethylpentene resin (DX820, manufactured by Mitsui Chemicals, Inc.) with a melt viscosity (η) of 1,300 poise, and a polystyrene resin (Japan A vented twin-screw extruder in which 20% by mass of Polystyrene G797N) and 20% by mass of a polypropylene resin having a melt viscosity of 2,000 poise (Gland Polymer Co., Ltd. J104WC) are temperature-controlled at 285°C. and pre-kneaded. This molten resin was continuously supplied to a vent-type single-screw kneader, kneaded and extruded, and the resulting strand was cooled and cut to prepare cavity-generating agent master pellets (M1).

(3) Preparation of master pellets M2 In addition, anatase type titanium dioxide particles with an average particle size of 0.3 μm (Fuji Titanium Co., Ltd. A mixture of 50% by mass of TA-300) was supplied to a vented twin-screw extruder and preliminarily kneaded. This molten resin was continuously supplied to a vented single-screw kneader, kneaded and extruded. The resulting strand was cooled and cut to prepare titanium dioxide-containing master pellets (M2).

(4) Production of white easy-adhesive polyester film

(Preparation of film raw material D1)
81% by mass of the polyethylene terephthalate resin having an intrinsic viscosity of 0.62 dl / g vacuum dried at 140 ° C. for 8 hours and 9% by mass of the master pellet (M1) vacuum dried at 90 ° C. for 4 hours, and the above 10% by mass of the master pellets (M2) were pellet-mixed to obtain a film raw material (D1).

(Production of unstretched film)
70% by mass of the same polyethylene terephthalate resin as used in the preparation of the film material (D1) and 30% by mass of the master pellets (M2) were added to the extruder for the Y layer in which the temperature of the film material (D1) was controlled at 285 ° C. were separately supplied to an X-layer extruder whose temperature was controlled at 290°C. The molten resin extruded from the extruder for the Y layer is led through an orifice, and the resin extruded from the extruder for the A layer is led to a feed book through a static mixer to form a layer (Y layer) composed of the film material (D1). and polyethylene terephthalate resin and master pellets (M2) (X layer) were laminated in the order of X layer/Y layer/X layer.

This molten resin was co-extruded in a sheet form from a T-die onto a cooling roll whose temperature was adjusted to 25°C, and adhered and solidified by an electrostatic application method to produce an unstretched film with a thickness of 510 µm. The discharge rate of each extruder was adjusted so that the thickness ratio of each layer was 1:8:1. At this time, the molten resin stayed in the melt line for about 12 minutes, and the shear rate received from the T-die was about 150/sec.

(Production of biaxially stretched film)
The resulting unstretched film was uniformly heated to 65°C using a heating roll, and was passed between two pairs of nip rolls with different peripheral speeds (low speed roll: 2 m/min, high speed roll: 6.8 m/min) at 3.4 It was longitudinally stretched twice. At this time, as an auxiliary heating device for the film, an infrared heater (rated output: 20 W / cm) equipped with a gold reflective film in the middle of the nip roll was placed on both sides of the film at a position 1 cm from the film surface and heated. . One side of the uniaxially stretched film thus obtained was coated with the above-mentioned coating solution by a reverse kiss coating method. After coating, the film is led to a tenter, heated to 150°C while being dried, transversely stretched to 3.7 times, fixed in width, subjected to heat treatment at 220°C for 5 seconds, and further relaxed 4% in the width direction at 200°C. Thus, a 50 μm-thick white easily adhesive polyester film was obtained. The b value of this film was 1.6.

(5) Production of printed matter (printed matter having a solvent-based ink layer)
On the easy-adhesive coating layer of the easy-adhesive polyester film, "screen ink manufactured by Jujo Chemical Co., Ltd."Solvent" was used to dilute Tetoron ink: Tetoron standard solvent = 4:1, and applied using a 250 mesh screen and a squeegee. After applying the ink, using a dry oven DVS602 manufactured by Yamato Scientific Co., Ltd., the ink was dried and cured at 90° C. for 5 minutes to obtain a printed matter.

(Printed Matter Having Oxidatively Polymerized Ink Layer)
On the easy-adhesive coating layer of the easy-adhesive polyester film, using an oxidative polymerization type offset ink [manufactured by Toyo Ink Mfg. Co., Ltd., product name "TSP400 G ink"], a printing machine [manufactured by Aki Seisakusho Co., Ltd., product name "RI Tester"] to obtain a printed matter.

(Printed matter having a melt-type thermal transfer ink layer)
On the easy-adhesive coating layer of easy-adhesive polyester film, using Sato's thermal transfer printer Scantronics CL4NX-J, Ricoh's thermal transfer ribbon B110C ink is printed at 6 inches / sec. 1-dimensional bar by arbitrary JAN code A code was printed to obtain a printed matter.

(Printed Matter Having LBP Toner Layer)
Using FUJI XEROX Co., Ltd. ApeosPort-V C3376 on the easy-adhesive coating layer of the easy-adhesive polyester film, a pattern arbitrarily created on the easy-adhesive coating layer of the easy-adhesive polyester film is printed to obtain a printed matter. rice field.

(Printed Matter Having UV Curable Ink Layer)
On the easy-adhesive coating layer of the easy-adhesive polyester film, a UV curable ink [T&K TOKA Co., Ltd., trade name “BEST CURE UV161 Indigo S”] is used to print with a central impression type printer. did. After weighing the ink with an anilox roll with a cell volume of 11 cm ³ /m ² , it was transferred to a solid plate and then to a film. The ink transferred on the film was cured with a 160 W/cm metal halide UV lamp to obtain a printed matter. The time from ink transfer to film to UV light irradiation was 1.88 seconds.

(Experimental example 2)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/76.0/19. A white easy-adhesive polyester film and a printed matter were obtained in the same manner as in Experimental Example 1, except that the value was changed to 0.
Cationic antistatic agent solution containing nitrogen element (A-1) 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 22.67 parts by mass Polyurethane resin solution (C-1) 4.80 parts by mass Particles 25.15 parts by mass (silica particles with an average particle size of 0.45 μm, solid content concentration 40.00 mass%)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 3)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/57.0/38. A white easy-adhesive polyester film and a printed matter were obtained in the same manner as in Experimental Example 1, except that the value was changed to 0.
Nitrogen-containing cationic antistatic agent solution (A-1) 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 17.00 parts by mass Polyurethane resin solution (C-2) 9.71 parts by mass Particles 25.15 parts by mass (silica particles with an average particle diameter of 0.45 μm, solid content concentration 40.00 mass%)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 4)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/57.0/38. A white easy-adhesive polyester film was obtained in the same manner as in Experimental Example 1, except that it was changed to 0.
Cationic antistatic agent solution (A-2) containing nitrogen element 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 17.00 parts by mass Polyurethane resin solution (C-1) 9.60 parts by mass Particles 25.15 parts by mass (silica particles with an average particle diameter of 0.45 μm, solid content concentration 40.00 mass%)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 5)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/57.0/38. A white easy-adhesive polyester film was obtained in the same manner as in Experimental Example 1, except that it was changed to 0.
Nitrogen-containing cationic antistatic agent solution (A-1) 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester resin solution (Bw-2) 20.40 parts by mass Polyurethane resin solution (C-1) 9.60 parts by mass Particles 25.15 parts by mass (silica particles with an average particle size of 0.45 μm, solid content concentration 40.00 mass %)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 6)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/57.0/38. A white easy-adhesive polyester film and a printed material were obtained in the same manner as in Experimental Example 1, except that the resin solid content thickness was changed to 0 and the coating was performed so that the thickness of the resin solid content was 650 nm.
Cationic antistatic agent solution containing nitrogen element (A-1) 3.30 parts by mass (solid content concentration 19.20% by mass)
Polyester water dispersion (Bw-1) 30.00 parts by mass Polyurethane resin solution (C-1) 16.95 parts by mass Particles 31.91 parts by mass (benzoguanamine formaldehyde condensate particles having an average particle size of 2 μm,
Solid content concentration 40.00% by mass)
Surfactant 0.40 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 7)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 6.5/60.7/32. A white easy-adhesive polyester film and a printed material were obtained in the same manner as in Experimental Example 1, except that the resin solid content thickness was changed to 8 and the coating was performed so that the resin solid content thickness was 50 nm.
Cationic antistatic agent solution containing nitrogen element (A-1) 2.45 parts by mass (solid content concentration 15.8% by mass)
Polyester water dispersion (Bw-1) 12.35 parts by mass Polyurethane resin solution (C-1) 6.27 parts by mass Surfactant 0.25 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 8)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/85.5/9. A white easy-adhesive polyester film and a printed matter were obtained in the same manner as in Experimental Example 1, except that it was changed to 5.
Nitrogen-containing cationic antistatic agent solution (A) 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 25.50 parts by mass Polyurethane resin solution (C-1) 2.40 parts by mass Particles 25.15 parts by mass (silica particles with an average particle size of 0.45 μm, solid content concentration 40.00 mass%)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 9)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/28.5/67. A white easy-adhesive polyester film and a printed matter were obtained in the same manner as in Experimental Example 1, except that the value was changed to 0.
Nitrogen-containing cationic antistatic agent solution (A) 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 8.50 parts by mass Polyurethane resin solution (C-1) 16.81 parts by mass Particles 25.15 parts by mass (silica particles with an average particle size of 0.45 μm, solid content concentration 40.00 mass%)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 10)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.0/57.0/38. A white easy-adhesive polyester film and a printed matter were obtained in the same manner as in Experimental Example 1, except that the value was changed to 0.
Nitrogen-containing cationic antistatic agent solution (A) 2.52 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 17.00 parts by mass Polyurethane resin solution (C-3) 11.33 parts by mass Particles 25.15 parts by mass (silica particles with an average particle size of 0.45 μm, solid content concentration 40.00 mass%)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 11)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.8/33.0/61. A white easy-adhesive polyester film and a printed matter were obtained in the same manner as in Experimental Example 1, except that it was changed to 2.
Nitrogen-containing cationic antistatic agent solution (A) 2.83 parts by mass (solid content concentration 17.50% by mass)
Polyester water dispersion (Bw-1) 9.33 parts by mass Polyurethane resin solution (C-4) 26.00 parts by mass Particles (a) 16.31 parts by mass (silica particles with an average particle size of 0.45 μm, solid content concentration 40.00% by mass)
Particles (b) 5.44 parts by mass (silica particles with an average particle size of 1.00 μm, solid content concentration of 40.00% by mass)
Surfactant 0.15 parts by mass (silicone type, solid content concentration 10% by mass)

(Experimental example 12)
The following coating agent was mixed with a mixed solvent of water and isopropanol, and the solid content mass ratio of the cationic antistatic agent containing nitrogen element/polyester resin/polyurethane resin solution was 5.8/33.0/61. A white easily adhesive polyester film and a printed material were obtained in the same manner as in Experimental Example 1, except that the resin solid content thickness was changed to 2 and the coating was performed so that the resin solid content thickness was 650 nm.
Nitrogen-containing cationic antistatic agent solution (A) 2.91 parts by mass (solid content concentration 19.20% by mass)
Polyester water dispersion (Bw-1) 11.67 parts by mass Polyurethane resin solution (C-4) 32.50 parts by mass Particles 21.27 parts by mass (benzoguanamine particles with an average particle size of 2.00 μm, solid content concentration 40.00 mass%)
Surfactant 0.45 parts by mass (silicone type, solid content concentration 10% by mass)

Tables 1 and 2 summarize the evaluation results of each experimental example.

The printed matter obtained in Experimental Examples 1 to 7 has excellent adhesion to various inks and toners, and in particular, the adhesion to an active energy ray-curable ink layer such as ultraviolet (UV) curable ink is excellent at high temperature and high humidity. It can be seen that the adhesion to the ink layer does not deteriorate even when stored in an environment. On the other hand, in Experimental Examples 8 to 12, any of the A value, the B/A value, and the contact angle to water of the base material having an easy-adhesive coating layer was inappropriate. When stored in a humid environment, the adhesion to various ink layers was not necessarily satisfactory.

According to the present invention, it has become possible to provide a printed material that is excellent in adhesion to various ink compositions and does not lose adhesion to the ink layer even when stored in a high-temperature and high-humidity environment.

Thin solid line: Measured data of the N1s spectrum of the surface of the easy-adhesive coating layer Dotted line: Curve showing the ionized nitrogen element peak separated from the N1s spectrum Broken line: Curve showing the non-ionized nitrogen element peak separated from the N1s spectrum (1): ionized nitrogen element peak (2): non-ionized nitrogen element peak

Claims

It has an easy-adhesive coating layer on a polyester film substrate, and at least one layer selected from UV-curing ink, solvent-based ink, oxidation polymerization ink, thermal transfer ink ribbon, and LBP toner on the easy-adhesive coating layer. Nitrogen ion concentration A (at%) and nitrogen element ratio B (at%) based on surface element distribution measurement by X-ray photoelectron spectroscopy on the surface of the easy-adhesive coating layer The printed matter satisfies the following formulas (i) and (ii), and the contact angle θ H 2 O of the easy-adhesive coating layer surface to water satisfies the following formula (iii).
(i) A (at%) > 0.4
(ii) 2.0 ≤ B/A ≤ 5.0
(iii) 50° ≤θH2O≤70 °
The printed matter according to claim 1, wherein the easily adhesive coating layer is formed by curing a composition containing a cationic antistatic agent, a polyurethane resin and a polyester resin.
3. The printed matter according to claim 1, wherein the polyester film base is a white polyester film base containing inorganic particles and/or a thermoplastic resin incompatible with the polyester resin.