JP7264294B2 - LAMINATED WHITE FILM AND RECORDING MATERIAL - Google Patents

Description

The present invention relates to laminated white films. More specifically, the present invention relates to a plastic sheet suitable as a recording material, which is an information printing medium that replaces paper, such as copying paper.

Currently, with the high performance of copiers and printers, these machines are used for printing and copying documents, as well as for printing photos and videos, issuing forms and slips, etc. Paper materials for various purposes and forms is used for the issuance of As a result, the amount of copier paper and printer paper consumed in companies and homes is increasing.

Since the mass consumption of paper, including copy paper and printer paper, is undesirable from the perspective of curbing deforestation, recycled paper is now being used by collecting used paper and disaggregating it into recycled pulp at paper mills. .
The main raw material for recycled paper is used paper that has been collected. Even if the utilization rate of paper rises, wood resources will still be consumed, and the use of recycled paper will not be a drastic solution for protecting the forest environment.
In addition, the quality of recycled paper is still inferior to that of high-quality paper, and when copying paper made from recycled paper is used, the whiteness of the paper decreases and the color becomes grayish. image quality tends to deteriorate.
In addition, recycled paper is expensive to manufacture and tends to be more expensive than wood-free paper.

Instead of such recycled paper, there has been proposed a paper that can be reused once by peeling and removing an image formed on the surface of the paper by an electrophotographic method such as a copying machine. For example, a paper mainly composed of cellulose fibers is used as a base, and a layer containing a polymer selected from polyvinyl alcohol, starch, carboxymethyl cellulose, polyvinyl acetate, and acrylic resin is provided on the image recording surface of the base. A reusable recording material is disclosed in which a toner-repellent layer containing a compound having a linear or branched alkyl group or alkenyl group is provided on a layer containing the compound (see, for example, Patent Document 1).
However, such a recording material has a thin polymer layer in order to reduce the cost of the polymer layer, and since it requires paper as a base, it does not completely eliminate the use of wood resources. It's not a solution for protection.

Therefore, as a material that completely replaces paper, synthetic paper made of plastic is being studied. For example, synthetic paper made of polypropylene is used for daily necessities. (See Patent Document 2, for example)

JP 2005-234162 A JP-A-10-204196

However, the synthetic paper described in Patent Document 2 is vulnerable to heat, and when used in copiers and printers that fix toner at relatively high temperatures, the synthetic paper melts and wrinkles in the copier, causing paper jams. could have occurred.

The present invention has been made in view of the above-mentioned circumstances, and the problem to be solved is that it can be used as a recording material that is an information printing medium that replaces paper such as copying paper, and is extremely cost-effective. to provide the film. It is also an object of the present invention to reduce jamming of film during the transport process in a copying machine as a recording material for copying paper or printer paper.

The gist of the present invention is that a polyester film having an apparent density of 0.7 to 1.3 g/cm ³ and a thickness of 10 to 1000 μm has a functional layer containing an antistatic agent on at least one side thereof, and The polyester film is a laminated white film characterized by containing a polymer incompatible with polyester.

The laminated white film of the present invention is used as a recording material that is an information printing medium that replaces paper, such as copying paper, by containing a polymer incompatible with polyester in addition to polyester in the polyester film as the base material. It is a plastic film that can be used and is extremely cost-effective. Furthermore, the laminated white film of the present invention can suitably transfer a toner image. That is, the toner image can be suitably transferred by a method such as an electrophotographic method, a thermal transfer method, or an ink jet method for transferring the toner image onto the recording material. In addition, after being used as a recording material, characters and images formed on the surface by toner and/or image forming substances can be easily peeled off.
In addition, since the polyester film has a functional layer containing an antistatic agent on at least one side thereof, it is possible to reduce clogging of the film during the transportation process in a copying machine as a recording material for copying paper or printer paper.

Furthermore, by including a release agent in the functional layer, after the recording material is used as described above, characters and images formed on the surface by a toner containing a thermoplastic resin and/or an image forming substance can be formed. can be easily peeled off and recycled. Therefore, the property of transferring the toner image, that is, the property of adhering the toner and/or image-forming substance to the film substrate, and the contradictory property of detachment of the toner and/or image-forming substance from the film substrate. It can be a film with both.

The present invention will now be described in more detail.

<This laminated white film>
As an example of a mode for carrying out the present invention, a laminated white film having a functional layer containing an antistatic agent on at least one side of a polyester film as a substrate (referred to as "this laminated white film") will be described.

<Polyester film>
The polyester film that serves as the base material of the laminated white film preferably has a polyester resin layer containing at least a polyester as a main component resin and a polymer incompatible with the polyester.
Here, the "main component resin" means a resin having the highest content ratio among the resin components constituting the polyester resin layer. It can be assumed that the main component resin accounts for 30% by mass or more, especially 50% by mass or more, and especially 80% by mass or more (including 100% by mass) of the resin components constituting the polyester resin layer.

The polyester film may be a single layer composed of the above polyester resin layer, or may be a multilayer including two layers, three layers, four layers or more including a polyester resin layer, and is particularly limited. isn't it.
Among them, it is preferably laminated in two or more layers, and a three-layer structure (surface layer/intermediate layer/surface layer) consisting of both surface layers and an intermediate layer is more preferable.
In addition, when the laminated structure is two layers, it means that it is composed of two surface layers. For example, it may be formed by layers.

(polyester)
The polyester constituting the polyester film as the substrate refers to those obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol.
Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. Examples of the aliphatic glycol include ethylene glycol, diethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol, 1 , 4-cyclohexanedimethanol and the like.

Typical polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalene dicarboxylate (PEN), polybutylene terephthalate and the like. Such polyesters may be homopolymers that are not copolymerized, and 20 mol % or less of the dicarboxylic acid component is a dicarboxylic acid component other than the main component, and/or 20 mol % or less of the diol component is a non-main component. It may be a copolyester that is a diol component. A mixture thereof may also be used.

Polyester can be obtained by a conventionally known method, for example, a method of directly obtaining a polyester by reacting a dicarboxylic acid and a diol, or a method of reacting a lower alkyl ester of a dicarboxylic acid and a diol with a conventionally known transesterification catalyst, followed by addition of a polymerization catalyst. It can be obtained by a method of performing a polymerization reaction below. As the polymerization catalyst, known catalysts such as antimony compounds, germanium compounds, titanium compounds and aluminum compounds can be used.

(Polymer incompatible with polyester)
By incorporating a polymer incompatible with polyester into the polyester film, the polyester film stretched at least uniaxially can contain a myriad of ultrafine cavities. Such microscopic cavities can make the polyester film not only scatter light and provide white opacity, but also reduce the apparent density of the polyester film. In addition, the image forming material containing a thermoplastic resin such as toner printed or printed on the surface of the polyester film can be easily peeled off.
By containing a polymer incompatible with polyester in the surface layer of the polyester film, when used as a recording material for copying paper or printer paper, thermoplastic resin such as toner printed or printed on the surface of the laminated white polyester film The contained image forming substance can be easily peeled off. Further, in order to ensure sufficient hiding power and weight reduction, the intermediate layer may contain a polymer incompatible with polyester, if necessary.

When the polyester film has a laminated structure, the polyester-incompatible polymer may be contained in all layers of the polyester film, or may be selectively contained in a specific layer. Specifically, the polyester-incompatible polymer may be contained in at least one surface layer of the polyester film or may be contained in the intermediate layer.

As the polymer incompatible with polyester, conventionally known polymers can be used. Examples thereof include polyolefin, polystyrene, polyacryl, polycarbonate, etc. Among them, polyolefin and polystyrene are preferable, and polyolefin is more preferable. Further, among polyolefins, polypropylene, polyethylene, poly-4-methylpentene-1, amorphous polyolefins and the like can be mentioned, and among them, polypropylene is more preferable in consideration of cavity formation and ease of film formation.

When polypropylene is used as the polymer incompatible with polyester, the content of propylene units in the polypropylene is preferably 80 mol% or more, more preferably 90 mol% or more, and still more preferably 95 mol% or more. By reducing the content of the copolymer obtained by copolymerizing units other than propylene units and using it within the above range, it is possible to sufficiently generate microvoids.

In the polyester resin layer, the content ratio of the polymer incompatible with the polyester is 1 to 70 parts by mass of the polymer incompatible with the polyester with respect to 100 parts by mass of the polyester. Preferably, it is contained in a proportion of 2 parts by mass or more or 50 parts by mass or less, more preferably 3 parts by mass or more or 40 parts by mass or less, and is contained in a proportion of 5 parts by mass or more or 35 parts by mass or less. Especially preferred.

When polypropylene is used as a polymer incompatible with polyester, the melt flow index of polypropylene under conditions of a temperature of 230° C. and a load of 2.16 kg (21.2 N) is usually 0.5 ml/10 minutes or more as a lower limit, It is preferably 1 ml/10 minutes or more, more preferably 3 ml/10 minutes or more, and still more preferably 5 ml/10 minutes or more. In the case of the above range, a sufficient size of the cavity can be generated, and breakage during stretching can be easily avoided.
On the other hand, the upper limit is usually 50 ml/10 minutes or less, preferably 40 ml/10 minutes or less, more preferably 30 ml/10 minutes or less, and even more preferably 25 ml/10 minutes or less. In the case of the above range, it is possible to avoid clipping during lateral stretching, and it is possible to maintain productivity.

The lower limit of the content of the polymer incompatible with polyester in the polyester film is usually 1% by weight or more, preferably 2% by weight or more, more preferably 3% by weight or more, still more preferably 5% by weight or more, particularly preferably 8% by weight or more. % by weight or more. By using it in the above range, a sufficient amount of microvoids is generated in the film, the hiding property of the film is improved, and the effect of reducing the apparent density, that is, the weight is sufficiently reduced. In addition, the slipperiness of the film and the writing ability with a pencil or the like are improved, which is advantageous for print transportability. Further, on the surface of the film, characters and images formed by printed toner and/or image-forming substances can be easily peeled off, making it possible to repeatedly use the film as a recording material for copy paper and printer paper. .
On the other hand, the upper limit of the content of the polymer incompatible with polyester in the polyester film is usually 70% by weight or less, preferably 50% by weight or less, more preferably 40% by weight or less, still more preferably 35% by weight or less, and particularly preferably is 30% by weight or less, most preferably 25% by weight or less. By using it in this range, the amount of cavities generated is not too large, and there is a tendency to easily suppress breakage during stretching.
In addition, when the polyester film has a laminated structure, the above content may mean the average content in all layers of the polyester film, or the content in a specific layer. Specifically, it may mean the content in at least one surface layer of the polyester film, or it may mean the content in the intermediate layer.

Further, when the polyester film has a structure of three or more layers, the intermediate layer is a recycled product such as the selvage generated during film production, the master roll selvage, and the master roll underwound within the scope of the present invention. May be blended. Containing recycled products has the effect of reducing costs and reducing environmental impact. The content of the recycled product in the intermediate layer is preferably 95% by weight or less, more preferably 85% by weight or less, relative to the intermediate layer from the viewpoint of film formation stability due to reduction in intrinsic viscosity in addition to color tone regulation. , more preferably 70% by weight or less, particularly preferably 60% by weight or less, and most preferably 40% by weight or less.

(metallic compound particles)
It is also possible to incorporate metallic compound particles into the polyester film for the purpose of further improving the hiding power and whiteness.
When the polyester film has a structure of three or more layers, it may be a surface layer or an intermediate layer. preferably.

Metallic compound particles used in polyester films tend to compensate for white opacity due to the light scattering effect caused by fine cavities caused by blending incompatible polymers, resulting in higher hiding and whiteness. There is a tendency.
Examples of metal compound particles to be used include known titanium oxide, calcium carbonate, barium sulfate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, zirconium oxide, and the like. , calcium carbonate, barium sulfate, etc., among which titanium oxide is particularly suitable.

The average particle size of the metal compound particles used has a lower limit of usually 0.05 µm or more, preferably 0.10 µm or more, more preferably 0.20 µm or more, and still more preferably 0.25 µm or more, and an upper limit of usually 0.50 µm or less. , preferably 0.45 μm or less, more preferably 0.40 μm or less. By using it in the above range, the degree of opacity when formed into a film becomes sufficient, and show-through tends to be improved particularly when the entire surface is printed on both sides of the film.

Furthermore, the lower limit of the content of the metal compound particles is preferably 1% by weight or more, more preferably 2% by weight or more, and still more preferably 3% by weight or more, and the upper limit is usually 30% by weight or less, preferably 20% by weight. % or less, more preferably 15 wt % or less, still more preferably 13 wt % or less, and particularly preferably 10 wt % or less. By setting it within the above range, it is possible to impart a sufficient degree of opacity, and it is also advantageous in terms of cost. tends to become a thing.
In addition, when the polyester film has a laminated structure, the above content may mean the average content in all layers of the polyester film, or the content in a specific layer. Specifically, it may mean the content in at least one surface layer of the polyester film, or it may mean the content in the intermediate layer.

(Particles other than metal compound particles)
Moreover, in order to improve the handleability and lubricity of the laminated white film, the polyester film may contain particles other than the metal compound particles exemplified above.
Specific examples of particles other than the metal compound particles exemplified above include silica particles and organic particles. Specific examples of organic particles include acrylic resins, styrene resins, urea resins, phenol resins, epoxy resins, and benzoguanamine resins. Among them, silica particles are preferable because they are particularly effective even in a small amount.

The average particle size of the particles (silica particles or organic particles) other than the metal compound particles exemplified above is preferably more than 0.50 μm, more preferably 1.0 μm or more, still more preferably 1.5 μm or more, and particularly preferably 2.0 μm or more. By setting it as the said range, it tends to become possible to provide sufficient slipperiness. The upper limit of the average particle size of the particles is usually 15.0 μm or less, preferably 12.0 μm or less, more preferably 10.0 μm or less, and even more preferably 8.0 μm or less. In the above range, the film surface does not become too rough, and characters and images such as toner and/or image forming substances printed on the film surface can be easily peeled off, and the film can be repeatedly used as copying paper. It tends to be possible to use it as a recording material for printer paper. Furthermore, it is not necessary to make the thickness of the surface layer extremely thick in terms of particle shedding, and the optimum range of the thickness is wide, which is a preferable form.

The shape of the particles (silica particles or organic particles) other than the metal compound particles exemplified above is also not particularly limited, and any of spherical, massive, rod-like, flattened and the like may be used. Moreover, there are no particular restrictions on its hardness, specific gravity, color, and the like. Two or more kinds of these particles may be used in combination, if necessary.

The content of particles (silica particles or organic particles) other than the metal compound particles exemplified above depends on the average particle size, so it cannot be said unconditionally, but for a polyester film containing silica particles or organic particles , usually 5% by weight or less, preferably 3% by weight or less, more preferably 2% by weight or less, still more preferably 1% by weight or less, and the lower limit of the preferred range is 0.005% by weight or more, more preferably 0.005% by weight or less, more preferably 0.005% by weight or less, more preferably 0.005% by weight or less. 05% by weight or more, more preferably 0.1% by weight or more. By using it in the above range, it becomes possible to make the surface roughness of the film moderate, and there is a tendency to achieve the desired lubricity. In addition to imparting lubricity, it becomes easy to peel and remove characters and images such as toner and / or image forming substances printed on the film surface, and the film is repeatedly used as a recording material such as copying paper and printer paper. It tends to be the best possible one. Furthermore, silica particles and organic particles tend to further improve the writability of pencils, mechanical pencils, ballpoint pens, and the like.
In addition, when the polyester film has a laminated structure, the above content may mean the average content in all layers of the polyester film, or the content in a specific layer. Specifically, it may mean the content in at least one surface layer of the polyester film, or it may mean the content in the intermediate layer.

(other ingredients)
Since the polyester film used as the base material for this laminated white polyester film contains an incompatible polymer, by stretching the extruded sheet in at least one direction, an extremely fine independent space can be created inside the film. can be obtained. Therefore, in order to further make the cavities extremely fine, or to increase the hiding power and whiteness, for example, surfactants, inert particles, fluorescent whitening agents, etc. may be blended.

In the polyester film, in addition to the above-mentioned particles and polymers incompatible with polyester, conventionally known antioxidants, heat stabilizers, lubricants, antistatic agents, fluorescent brighteners, dyes, pigments, etc. can be added. Further, depending on the application, an ultraviolet absorber, particularly a benzoxazinone-based ultraviolet absorber, etc. may be contained.

(In the case of laminated structure)
When the polyester film as the base material of the present laminated white polyester film has a laminated structure of two or more layers, it is preferable that any one of the two layers or more has a surface layer of the polyester resin layer of three or more layers.

For example, in the case of a laminated structure of three or more layers, if the surface layer contains the above polyester and a polymer incompatible with the polyester, fine cavities can be provided by stretching, so that weight reduction, concealability and Whitening can be achieved. Furthermore, since the surface roughness can be adjusted, the writability can be improved, and the toner and the image forming substance can be peeled off after use.
If the surface layer further contains metal compound particles, the hiding power and whiteness can be further improved, and by containing particles other than the metal compound particles, slipperiness can be improved.

On the other hand, as long as the intermediate layer other than the surface layer contains the polyester, it may optionally contain a polymer incompatible with the polyester, metal compound particles, and particles other than the metal compound particles. It is preferable to reduce the content of the metal compound particles and particles other than the metal compound particles as much as possible, and to use polyester as a recycled product in combination from the viewpoint of cost reduction and environmental load reduction.

(thickness)
The thickness of the polyester film is preferably 10 μm to 1000 μm, more preferably 20 μm or more and 500 μm or less, more preferably 30 μm or more and 400 μm or less, more preferably 38 μm or more and 350 μm or less.
By using it in the above range, the stiffness and handleability of the film can be made sufficient, and clogging of the film during the transport process in the copying machine can be reduced.

When the polyester film has a laminated structure of three or more layers as described above, the thickness of each surface layer is preferably 1 μm to 50 μm, especially 2 μm or more or 40 μm or less, especially 3 μm or more or 30 μm or less, especially 4 μm More preferably, it is 25 μm or more or 25 μm or less. By using it in the above range, it becomes possible to fully exhibit the performance of the metal compound particles and particles other than the metal compound particles described later, and the production cost can be kept low.

(apparent density)
The lower limit of the apparent density of the polyester film is 0.7 g/cm ³ or more, preferably 0.75 g/cm ³ or more, more preferably 0.8 g/cm ³ or more. By setting it to the above range, the strength of the film can be maintained, and clogging of the film in the transport process in the copying machine can be reduced when using it as a recording material instead of paper for copying paper or printer paper, which is an information printing medium. This makes it possible to perform optimal printing/printing.
On the other hand, the upper limit of the apparent density is 1.3 g/cm ³ or less, preferably 1.2 g/cm ³ or less, more preferably 1.1 g/cm ³ or less. By setting it within the above range, it is possible to reduce the work burden when carrying a large amount of printed materials, and to reduce the environmental impact and cost by reducing the _CO2 generated in the film (sheet) transportation process. .
The apparent density of the polyester film is adjusted by blending an incompatible polymer with a lighter specific gravity than the main resin, polyester, and stretching the film in at least one direction to form very fine independent cavities inside the film. can be done. However, it is not limited to these methods.

<Physical properties of polyester film>
The surface arithmetic mean roughness (SRa) of the polyester film varies depending on the application, but the upper limit is usually 950 nm or less, preferably 850 nm or less, more preferably 800 nm or less. By using the arithmetic average roughness (SRa) within the above range, characters and images such as toner containing thermoplastic resin and/or image forming substance formed on the film surface by printing or printing can be easily peeled off and removed. Therefore, the film tends to be used repeatedly as a recording material for copying paper and printer paper.
On the other hand, the lower limit of the arithmetic mean roughness (SRa) is usually 100 nm or more, preferably 200 nm or more, more preferably 300 nm or more, still more preferably 350 nm or more. By setting the thickness within the above range, it becomes possible to obtain sufficient concealability and transportability, and it tends to be possible to obtain a film most suitable for use as a recording material for copying paper and printer paper. Furthermore, there is a tendency to have sufficient writability.

The b value (reflection method), which is an index representing the yellowness of the polyester film, is usually 0 or less, preferably -0.20 or less, more preferably -0.40 or less, more preferably -0.50 or less, particularly preferably is -0.60 or less, and the lower limit is not particularly limited, but -5.0 or more is preferable. By using it in the above range, the yellowness can be suppressed and the whiteness can be improved. Furthermore, when used as a recording material for color printing, the resulting image tends to be of excellent quality.

The polyester film has a heat shrinkage rate of 2.8% or less, preferably 2.3% or less, more preferably 2.3% or less as an absolute value in the film longitudinal direction (MD) and the film width direction (TD) at 150 ° C. for 30 minutes. 2.0% or less.
By setting the heat shrinkage rate within the above range, when printing or printing on a recording material by a method such as an electrophotographic method or a thermal transfer method in which a toner image is transferred to the recording material, the dimensional stability of the film is improved due to the influence of heat. In particular, the edge of the film (sheet), that is, the part where wrinkles are likely to occur, can also suppress the occurrence of wrinkles, resulting in distortion and unevenness in characters and images. As a result, it tends to be possible to suppress the phenomenon that the image quality deteriorates. In addition, since wrinkles cannot be erased once they occur, the wrinkles cannot be repeatedly used as a recording material for copying paper or printer paper.

The opacity (OD) of the polyester film is usually 0.30 or more, preferably 0.35 or more, more preferably 0.40 or more, and still more preferably 0.45 or more, as measured by a single film using a Macbeth densitometer. is. By using the amount within the above range, show-through is reduced when the entire surface is printed on both sides of the film, and it tends to be possible to obtain high-quality characters and images. On the other hand, the upper limit of the opacifying property (OD) is not particularly limited, but considering the balance of other physical properties, it is preferably 1 or less, more preferably 0.9 or less.

As for the whiteness of the polyester film, the Hunter whiteness (Wb) of a single film is measured with a colorimeter, and the lower limit is usually 80.0% or more, preferably 81.0% or more, more preferably 82.0%. It is 0% or more, more preferably 83.0% or more, and particularly preferably 83.5% or more. By keeping the whiteness within the above range, when used as a recording material for copying paper and printer paper, which are information printing media that replace paper, especially when color printing is performed, characters and images can be produced with high definition. , and tends to be favorable in terms of quality. Also, although it depends on the intended use, it is preferably as high as possible in order to give a sense of luxury, and the upper limit is not particularly limited. On the other hand, when used in applications where gloss is a concern, the upper limit of the preferred range is 95.0% or less.

<Function layer>
Formation of the functional layer that constitutes the laminated white film will be described.
The functional layer in the present laminated white film preferably has antistatic performance and release performance.
In the laminated white film, the apparent density can be reduced, the whitening can be performed without incurring costs, and characters and images such as printed or printed thermoplastic resin-containing toners and/or image-forming substances can be easily formed. In order to realize that it can be easily peeled and removed, it is preferable to have a polyester resin layer containing polyester and a polymer incompatible with polyester, and it is more preferable that the polyester resin layer has a surface layer. However, it was found that when a functional layer is provided, it tends to be difficult to develop the ability to easily peel and remove characters and images such as toner and/or image forming substances on the surface. Preferably, the layer also has release properties.

[Antistatic agent]
When using this laminated white film as a recording material for copying paper or printer paper, which can suitably transfer the toner image by a method such as an electrophotographic method or a thermal transfer method that transfers the toner image to the recording material, it is For the purpose of preventing multi-feeding during sheet transport and preventing sheets from sticking to each other when handling sheets, it is preferable to have a functional layer containing an antistatic agent on at least one side. In addition, by containing an antistatic agent, there is no jamming of the film in the multifunction machine, there is no occurrence of double feeding of the printed film, each sheet can be transported independently, and dust adhesion is prevented. Since it can be prevented, it is possible to obtain a good quality film or a film print with a good image quality.

The antistatic agent contained in the functional layer is not particularly limited, and conventionally known antistatic agents can be used. For example, a polymer type antistatic agent is preferable because it has good heat resistance and moist heat resistance.
Polymer-type antistatic agents include, for example, compounds having an ammonium group, polyether compounds, compounds having a sulfonic acid group, betaine compounds, and conductive polymers.
Compounds with an ammonium group or compounds with a sulfonic acid group are preferable in terms of antistatic performance, and compounds with an ammonium group are more preferable in consideration of compatibility with other materials that form the functional layer, such as release agents. preferable. Moreover, the conductive polymer is most excellent in antistatic property and is preferable. However, the material is expensive and its use may be restricted in applications where coloring is extremely disliked.

Examples of the compound having an ammonium group include ammonium compounds of aliphatic amines, alicyclic amines, and aromatic amines. The compound having an ammonium group is preferably a polymer-type compound having an ammonium group, and the ammonium group is incorporated not as a counterion but in the main chain or side chain of the polymer. is preferred. For example, a polymer obtained by polymerizing a monomer containing an addition-polymerizable ammonium group or a precursor of an ammonium group such as an amine may be mentioned, and is preferably used. As the polymer, a monomer containing an addition-polymerizable ammonium group or an ammonium group precursor such as an amine may be polymerized alone, or a copolymer of a monomer containing these and other monomers may be used. may

Among compounds having an ammonium group, compounds having a pyrrolidinium ring are also preferable in that they are excellent in antistatic properties and heat resistance.

The two substituents bonded to the nitrogen atom of the pyrrolidinium ring-containing compound are each independently an alkyl group, a phenyl group, or the like, and even if these alkyl groups and phenyl groups are substituted with groups shown below, good. Substitutable groups are, for example, hydroxyl groups, amide groups, ester groups, alkoxy groups, phenoxy groups, naphthoxy groups, thioalkoxy groups, thiophenoxy groups, cycloalkyl groups, trialkylammoniumalkyl groups, cyano groups, halogens. Also, the two substituents attached to the nitrogen atom may be chemically bonded, for example, -(CH ₂ )m- (m = an integer of 2 to 5), -CH(CH ₃ )CH (CH ₃ )-, -CH=CH-CH=CH-, -CH=CH-CH=N-, -CH=CH-N=CH-, -CH ₂ OCH ₂ -, -(CH ₂ ) ₂ O (CH ₂ ) ₂ — and the like.

A polymer having a pyrrolidinium ring is obtained by cyclopolymerizing a diallylamine derivative using a radical polymerization catalyst. Polymerization is carried out in a polar solvent such as water or methanol, ethanol, isopropanol, formamide, dimethylformamide, dioxane, or acetonitrile as a solvent with a polymerization initiator such as hydrogen peroxide, benzoyl peroxide, or tertiary butyl peroxide. It can be implemented by any method, but is not limited to these. In the present invention, a diallylamine derivative and a compound having a polymerizable carbon-carbon unsaturated bond may be used as a copolymerization component.

Moreover, it is also preferable that the antistatic agent is a polymer having the structure of the following formula (1) from the viewpoint of excellent antistatic properties and moist heat resistance stability. A single polymer or copolymer having the structure of the following formula (1), or further, a plurality of other components may be copolymerized.

For example, in the above formula, the substituent R ¹ is a hydrogen atom or a hydrocarbon group such as an alkyl group having 1 to 20 carbon atoms or a phenyl group; R ² is —O—, —NH— or ^—S— ; An alkylene group having 1 to 20 carbon atoms or other structures capable of forming the structure of Formula 1, R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a phenyl group. or a hydrocarbon group to which a functional group such as a hydroxyalkyl group is added, X- is a counter ion of various kinds.

Among the above, from the viewpoint of particularly excellent antistatic properties and wet heat resistance stability, in formula (1), the substituent R ¹ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ³ is preferably an alkyl group having 1 to 6 carbon atoms, and R ⁴ , R ⁵ and R ⁶ are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably , R ⁴ , R ⁵ and R ⁶ is a hydrogen atom, and the other substituent is an alkyl group having 1 to 4 carbon atoms.

Examples of the anion that serves as a counter ion for the ammonium group of the compound having an ammonium group include halogen ions, sulfonate, sulfate, phosphate, nitrate, and carboxylate ions.

Also, the number average molecular weight of the compound having an ammonium group is usually 1,000 to 500,000, preferably 2,000 to 350,000, more preferably 5,000 to 200,000. If the molecular weight is less than 1,000, the strength of the functional layer may be weak, or the heat resistance stability may be poor. On the other hand, when the molecular weight exceeds 500,000, the viscosity of the coating liquid increases, and the handleability and coating properties may deteriorate.

Polyether compounds include, for example, polyethylene oxide, polyether ester amide, acrylic resins having polyethylene glycol in side chains, and the like.

A compound having a sulfonic acid group is a compound containing a sulfonic acid or a sulfonate in the molecule. For example, a compound in which a large amount of sulfonic acid or a sulfonate exists, such as polystyrene sulfonic acid, is preferably used. .

Examples of conductive polymers include polythiophene-based, polyaniline-based, polypyrrole-based, and polyacetylene-based polymers. It is preferably used. Conductive polymers are preferred over the other antistatic agents described above in that they have a lower resistance value. However, on the other hand, it is necessary to devise measures such as reducing the amount used in applications where coloring and cost are concerns.

The lower limit of the content of the antistatic agent in the functional layer is usually 1% by weight or more, preferably 3% by weight or more, more preferably 5% by weight or more, still more preferably 10% by weight or more, and particularly preferably 20% by weight or more. be. The upper limit is usually 80% by weight or less, preferably 70% by weight or less, more preferably 60% by weight or less, still more preferably 55% by weight or less, and particularly preferably 50% by weight or less. By using it in the above range, it is possible to obtain sufficient antistatic properties, it is effective in preventing sticking between films and adhesion of dust, and it is said to be excellent in print transportability and image quality. tend to become

[Release agent]
The functional layer is imparted with releasability so that characters such as toner containing a thermoplastic resin formed on the film surface and image-forming substances can be suitably peeled off after printing or printing. preferably. It has been found that the function of peeling and removing the toner and/or the image-forming substance can be performed more appropriately by imparting a releasing property to the functional layer. In other words, the present inventors have found a technique for realizing the conflicting properties of adhesiveness and peelability with a single functional layer to a higher degree. This technology can be said to be a highly effective technology considering that peeling performance cannot be achieved with a functional layer having general adhesive performance, while adhesive performance cannot be achieved with a functional layer having general peeling performance. . Moreover, even if a functional layer having adhesive performance and a functional layer having peeling performance are laminated, neither performance can be exhibited, and only the performance of the outermost functional layer is reflected.
The functional layer preferably contains a release agent in order to impart release properties to toner and/or image forming substances.

The release agent is not particularly limited, and conventionally known release agents can be used. Examples thereof include long-chain alkyl group-containing compounds, fluorine compounds, silicone compounds, waxes, and the like. Among these, long-chain alkyl compounds and fluorine compounds are preferable, and long-chain alkyl compounds are more preferable, from the viewpoint of less staining and excellent peeling and removal of image forming substances. In addition, a silicone compound is preferable when it is particularly important to remove the image forming substance by peeling. Wax is also effective when the printability of the image forming substance on the surface is to be emphasized. These release agents may be used alone or in combination.

Further, when the functional layer is provided by coating, from the viewpoint of the wettability of the base material to the film, among the above release agents, compounds containing long-chain alkyl groups are preferable.

A long-chain alkyl group-containing compound is a compound having a linear or branched alkyl group usually having 6 or more, preferably 8 or more, more preferably 12 or more carbon atoms.
Examples of alkyl groups include hexyl group, octyl group, decyl group, lauryl group, octadecyl group, and behenyl group.
Examples of compounds having an alkyl group include various long-chain alkyl group-containing polymer compounds, long-chain alkyl group-containing amine compounds, long-chain alkyl group-containing ether compounds, long-chain alkyl group-containing quaternary ammonium salts, and the like. . Considering heat resistance and stain resistance, a polymer compound is preferable. Moreover, from the viewpoint of obtaining releasability effectively, a polymer compound having a long-chain alkyl group in a side chain is more preferable.

A polymer compound having a long-chain alkyl group in a side chain can be obtained by reacting a polymer having a reactive group with a compound having an alkyl group capable of reacting with the reactive group. Examples of the reactive groups include hydroxyl groups, amino groups, carboxyl groups, acid anhydrides, and the like. Examples of compounds having these reactive groups include polyvinyl alcohol, polyethyleneimine, polyethyleneamine, reactive group-containing polyester resins, and reactive group-containing poly(meth)acrylic resins. Among these, polyvinyl alcohol is preferable in consideration of releasability and ease of handling.

The compound having an alkyl group capable of reacting with the reactive group includes, for example, hexyl isocyanate, octyl isocyanate, decyl isocyanate, lauryl isocyanate, octadecyl isocyanate, behenyl isocyanate, and other long-chain alkyl group-containing isocyanates; hexyl chloride, octyl chloride long-chain alkyl group-containing acid chlorides such as , decyl chloride, lauryl chloride, octadecyl chloride and behenyl chloride; long-chain alkyl-group-containing amines; and long-chain alkyl-group-containing alcohols. Among these, long-chain alkyl group-containing isocyanates are preferred, and octadecyl isocyanate is particularly preferred, in consideration of releasability and ease of handling.

Polymer compounds having long-chain alkyl groups in side chains can also be obtained by polymerizing long-chain alkyl (meth)acrylates or by copolymerizing long-chain alkyl (meth)acrylates with other vinyl group-containing monomers. . Examples of long-chain alkyl (meth)acrylates include hexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, and behenyl (meth)acrylate. be done.

A fluorine compound is a compound containing a fluorine atom in the compound. Polymers containing fluorine atoms are preferred for reducing staining. Organic fluorine compounds are preferably used in terms of coating appearance by in-line coating, and examples thereof include perfluoroalkyl group-containing compounds, polymers of olefin compounds containing fluorine atoms, and aromatic fluorine compounds such as fluorobenzene. . A perfluoroalkyl group-containing compound is preferable from the viewpoint of releasability. Furthermore, compounds containing long-chain alkyl compounds as described later can also be used as fluorine compounds.

The perfluoroalkyl group-containing compound includes, for example, perfluoroalkyl (meth)acrylate, perfluoroalkylmethyl (meth)acrylate, 2-perfluoroalkylethyl (meth)acrylate, 3-perfluoroalkylpropyl (meth)acrylate, Perfluoroalkyl group-containing (meth)acrylates such as 3-perfluoroalkyl-1-methylpropyl (meth)acrylate and 3-perfluoroalkyl-2-propenyl (meth)acrylate, polymers thereof, perfluoroalkylmethyl vinyl ether, Perfluoroalkyl group-containing vinyl ethers such as 2-perfluoroalkylethyl vinyl ether, 3-perfluoropropyl vinyl ether, 3-perfluoroalkyl-1-methylpropyl vinyl ether, 3-perfluoroalkyl-2-propenyl vinyl ether, polymers thereof, etc. is mentioned. Considering heat resistance and stain resistance, it is preferably a polymer. The polymer may be a single compound or a polymer of multiple compounds.

From the viewpoint of releasability, the perfluoroalkyl group preferably has 3 to 11 carbon atoms. Further, it may be a polymer with a compound containing a long-chain alkyl compound as described later. Moreover, from the viewpoint of adhesion to the base material, it is also preferable to be a polymer with vinyl chloride.

A silicone compound is a compound having a silicone structure in its molecule, and examples thereof include alkylsilicones such as dimethylsilicone and diethylsilicone, and phenylsilicone and methylphenylsilicone having a phenyl group. Silicones having various functional groups can also be used, for example, ether groups, hydroxyl groups, amino groups, epoxy groups, carboxylic acid groups, halogen groups such as fluorine, perfluoroalkyl groups, various alkyl groups and various Examples thereof include hydrocarbon groups such as aromatic groups. As other functional groups, silicones with vinyl groups and hydrogen silicones in which hydrogen atoms are directly bonded to silicon atoms are also common, and both are used together to form addition-type silicones (those resulting from addition reactions between vinyl groups and hydrogen silane). It can also be used as

Modified silicones such as acrylic-grafted silicone, silicone-grafted acrylic, amino-modified silicone, and perfluoroalkyl-modified silicone can also be used as the silicone compound. Considering heat resistance and contamination resistance, it is preferable to use a curable silicone resin, and any curing reaction type such as condensation type, addition type, active energy ray curing type can be used as the type of curing type.

Wax is selected from natural waxes, synthetic waxes, and waxes blended with them.

Natural waxes include vegetable waxes, animal waxes, mineral waxes, and petroleum waxes. Plant waxes include candelilla wax, carnauba wax, rice wax, Japan wax, jojoba oil and the like. Animal waxes include beeswax, lanolin, whale wax and the like. Mineral waxes include montan wax, ozokerite, and ceresin. Petroleum wax includes paraffin wax, microcrystalline wax, petrolatum, and the like. Synthetic waxes include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, acid amides, amines, imides, esters, ketones and the like.

Synthetic waxes include, for example, Fischer-Tropsch wax (also known as Sasol wax) and polyethylene wax. ie, polypropylene, ethylene-acrylic acid copolymer, polyethylene glycol, polypropylene glycol, block or graft combination of polyethylene glycol and polypropylene glycol, and the like.

Modified waxes include montan wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives and the like. The derivative here is a compound obtained by purification, oxidation, esterification, saponification, or a combination thereof. Hydrogenated waxes include hydrogenated castor oil and hydrogenated castor oil derivatives.

Among them, from the viewpoint of stabilizing properties such as blocking, synthetic waxes are preferred as the release agent in the functional layer, polyethylene waxes are more preferred, and oxidized polyethylene waxes are even more preferred. The number average molecular weight of the synthetic wax is usually 500 to 30,000, preferably 1,000 to 15,000, and more preferably 2,000 to 8,000 from the viewpoints of stability of properties such as blocking and handleability.

The lower limit of the release agent content in the functional layer is usually 0% by weight or more, preferably 3% by weight or more, more preferably 5% by weight or more, still more preferably 8% by weight or more, and particularly preferably 10% by weight or more. be. The upper limit is usually 80% by weight or less, preferably 70% by weight or less, more preferably 60% by weight or less, even more preferably 50% by weight or less, and particularly preferably 40% by weight or less. By using it in the above range, it tends to be possible to improve the releasability while ensuring the adhesiveness to the toner, the image forming substance, etc., so that the image forming substance can be easily peeled off.

[polymer]
In order to improve the adhesion between the functional layer and toner and/or image forming substances, etc., to facilitate the formation of the functional layer, or to improve the wettability of the base film when the functional layer is provided by coating, the functional The layer preferably contains a polymer (a polymer other than the above-described antistatic agent, release agent, and cross-linking agent described below).

Conventionally known polymers can be used as the polymer used for the functional layer. Specific examples of the polymer include acrylic resin, urethane resin, polyester resin, polyvinyl (polyvinyl alcohol, vinyl chloride vinyl acetate copolymer, etc.), polyalkylene glycol, polyalkyleneimine, methylcellulose, hydroxycellulose, starches, and the like. . Among these, acrylic resins, urethane resins, polyester resins, and polyvinyl alcohol are preferred from the viewpoint of improving the appearance, adhesion to the substrate film, and stabilizing antistatic performance and release performance. Acrylic resins, urethane resins, Polyester resins are more preferred, and acrylic resins and urethane resins are even more preferred. Acrylic resins and polyvinyl alcohol are preferable from the viewpoint of stabilization of antistatic performance and release performance, and stability in the state of a coating liquid when a functional layer is formed by coating. Considering overall performance, acrylic resins or urethane resins are preferred, and acrylic resins are particularly preferred.

The acrylic resin as the polymer contained in the functional layer is a polymer composed of polymerizable monomers including acrylic and methacrylic monomers. These may be homopolymers, copolymers, or copolymers with polymerizable monomers other than acrylic and methacrylic monomers. Copolymers of these polymers with other polymers (eg, polyester, polyurethane, etc.) are also included. Examples are block copolymers and graft copolymers. Alternatively, a polymer obtained by polymerizing a polymerizable monomer in a polyester solution or a polyester dispersion (sometimes a mixture of polymers) is also included. Also included are polymers obtained by polymerizing polymerizable monomers in polyurethane solutions and polyurethane dispersions (mixtures of polymers in some cases). Also included are polymers (polymer mixtures in some cases) obtained by polymerizing polymerizable monomers in other polymer solutions or dispersions in the same manner. Moreover, it is possible to contain a hydroxyl group and an amino group in order to further improve adhesion.

The polymerizable monomer is not particularly limited, but particularly representative compounds include various carboxyl group-containing compounds such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid. Monomers, and salts thereof; such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, monobutylhydroxyl fumarate, monobutylhydroxyitaconate various hydroxyl group-containing monomers; various (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate; ( various nitrogen-containing compounds such as meth)acrylamide, diacetoneacrylamide, N-methylolacrylamide or (meth)acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, vinyltoluene; various vinyl esters such as; various silicon-containing polymerizable monomers such as γ-methacryloxypropyltrimethoxysilane and vinyltrimethoxysilane; phosphorus-containing vinyl monomers; vinyl halides; and various conjugated dienes such as butadiene.

The urethane resin as the polymer contained in the functional layer is a polymer compound having urethane bonds in the molecule, and is usually prepared by reaction of polyol and isocyanate. Polyols include polyester polyols, polycarbonate polyols, polyether polyols, polyolefin polyols, and acrylic polyols, and these compounds may be used singly or in combination.

The above polyester 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 and polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butane Diol, 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.), lactones such as polycaprolactone Examples include those having a compound derivative unit.

The above-mentioned polycarbonate polyols are obtained by a dealcoholization reaction from polyhydric alcohols and carbonate compounds. Polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentane Diol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane diol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane and the like. Examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, ethylene carbonate, etc. Polycarbonate-based polyols obtained from these reactions include, for example, poly(1,6-hexylene) carbonate, poly(3- methyl-1,5-pentylene)carbonate and the like.

Examples of the above polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol and the like.

Among the above polyols, polyester polyols and polycarbonate polyols are more preferable in consideration of compatibility with other components of the functional layer, stabilization of antistatic performance and release performance, and the like.

Examples of the polyisocyanate compound used to obtain the urethane resin include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, tolidine diisocyanate, α, α, α', Aliphatic diisocyanates having aromatic rings such as α'-tetramethylxylylene diisocyanate, aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate , dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl diisocyanate. These may be used alone or in combination of multiple types.

A chain extender may be used when synthesizing the urethane resin, and the chain extender is not particularly limited as long as it has two or more active groups that react with isocyanate groups. Alternatively, a chain extender having two amino groups can be mainly used.

Examples of the chain extender having two hydroxyl groups include aliphatic glycols such as ethylene glycol, propylene glycol and butanediol; aromatic glycols such as xylylene glycol and bishydroxyethoxybenzene; and neopentyl glycol hydroxypivalate. Glycols such as ester glycols of Examples of chain extenders having two amino groups include aromatic diamines such as tolylenediamine, xylylenediamine, diphenylmethanediamine, ethylenediamine, propylenediamine, hexanediamine, 2,2-dimethyl-1,3- Propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10- aliphatic diamines such as decanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylitincyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, 1 , and alicyclic diamines such as 3-bisaminomethylcyclohexane.

The above urethane resin may use a solvent as a medium. Preferably water is used as the medium.
For dispersing or dissolving the urethane resin in water, there are a forced emulsification type using an emulsifier, a self-emulsification type in which a hydrophilic group is introduced into the urethane resin, a water-based type, and the like. In particular, a self-emulsifying type in which an ionic group is introduced into the structure of a urethane resin to form an ionomer is preferable because it is excellent in the storage stability of the liquid and the water resistance and transparency of the resulting functional layer.

At this time, various ionic groups such as carboxyl group, sulfonic acid, phosphoric acid, phosphonic acid, and quaternary ammonium salt can be used as the ionic group to be introduced. As a method for introducing a carboxyl group into a urethane resin, various methods can be adopted in each stage of the polymerization reaction. For example, there is a method of using a resin having a carboxyl group as a copolymerization component when synthesizing a prepolymer, and a method of using a component having a carboxyl group as one component such as a polyol, polyisocyanate, or chain extender. In particular, a method of using a carboxyl group-containing diol and introducing a desired amount of carboxyl groups depending on the charged amount of this component is preferred.

For example, dimethylolpropionic acid, dimethylolbutanoic acid, bis-(2-hydroxyethyl)propionic acid, bis-(2-hydroxyethyl)butanoic acid, etc. can be copolymerized with the diol used in the polymerization of the urethane resin. can be done. The carboxyl group is preferably neutralized with ammonia, amines, alkali metals, inorganic alkalis or the like to form a salt. Particularly preferred are ammonia, trimethylamine and triethylamine. In such a urethane resin, the carboxyl groups removed from the neutralizing agent in the drying process after application can be used as cross-linking reaction points by other cross-linking agents. As a result, the stability of the liquid state before coating is excellent, and the durability, solvent resistance, water resistance, blocking resistance, etc. of the obtained functional layer can be further improved.

The polyester resin as the polymer to be contained in the functional layer includes, as main constituents, for example, those composed of the following polyvalent carboxylic acid and polyvalent hydroxy compound. That is, polyvalent carboxylic acids include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic acid, 4,4′-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid and 2,6 -naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-potassium sulfoterephthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, trimesic acid, pyromellitic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic acid monopotassium salt, ester-forming derivatives thereof, and the like can be used. , Polyvalent hydroxy compounds include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2 -methyl-1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene Glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene oxide glycol, dimethylolpropionic acid, glycerin, trimethylolpropane, sodium dimethylolethylsulfonate, potassium dimethylolpropionate etc. can be used. One or more of these compounds may be appropriately selected, and a polyester resin may be synthesized by a conventional polycondensation reaction.

Polyvinyl alcohol as the polymer to be contained in the functional layer has a polyvinyl alcohol moiety. Alcohol can be used. Although the degree of polymerization of polyvinyl alcohol is not particularly limited, it is usually 100 or more, preferably in the range of 300 to 40,000. If the degree of polymerization is less than 100, the water resistance of the functional layer may deteriorate. The degree of saponification of polyvinyl alcohol is not particularly limited, but is preferably 50 mol% or more, more preferably 70 to 99 mol%, still more preferably 80 to 98 mol%, particularly preferably 86 to 97 mol%. It is a polyvinyl acetate saponification product.

The lower limit of the polymer content in the functional layer is usually 0% by weight or more, preferably 3% by weight or more, more preferably 5% by weight or more, still more preferably 10% by weight or more, and particularly preferably 15% by weight or more. The upper limit is usually 80% by weight or less, preferably 70% by weight or less, more preferably 60% by weight or less, still more preferably 55% by weight or less, and particularly preferably 50% by weight or less. By using it in the above range, it is possible to easily form the image forming substance, improve the adhesion with the base film, and improve the wettability to the base film when providing the functional layer by coating, resulting in an excellent appearance. tend to be easier to achieve.

[Crosslinking agent]
It is preferable to further contain a cross-linking agent in order to increase the strength of the functional layer and to improve the adhesiveness to the toner and/or the image forming substance.
As the cross-linking agent, conventionally known materials can be used, for example, oxazoline compounds, isocyanate compounds, epoxy compounds, melamine compounds, carbodiimide compounds, silane coupling compounds, hydrazide compounds, aziridine compounds, and the like. Among them, oxazoline compounds, isocyanate compounds, epoxy compounds, melamine compounds, carbodiimide compounds, and silane coupling compounds are preferred. Melamine compounds and oxazoline compounds are preferred for further strengthening the strength of the functional layer, and oxazoline compounds, isocyanate compounds, epoxy compounds, and carbodiimide compounds are preferred for improving adhesion to the substrate film. In particular, oxazoline compounds and isocyanate compounds are preferred.

In addition, by including a cross-linking agent in the functional layer, there is a tendency that the property of improving the wettability to the base film can be imparted.
According to the studies of the present inventors, when the polyester film as the substrate contains a polymer incompatible with polyester, particularly polyolefin, the wettability is extremely poor when the functional layer is provided by coating. It was found that the coating liquid was repelled. However, it was unexpectedly found that the wettability is greatly improved by including a cross-linking agent in the functional layer.

As the cross-linking agent, the above-mentioned materials can be used. Among them, oxazoline compounds, isocyanate compounds, epoxy compounds, and silane coupling compounds are preferable for improving wettability, and among them, oxazoline compounds and isocyanate compounds are more preferable. . That is, when considered comprehensively, the most preferable material as a cross-linking agent is an oxazoline compound or an isocyanate compound. Moreover, one type of these crosslinking agents may be used, or two or more types may be used in combination.

As the oxazoline compound used as the cross-linking agent, a polymer containing an oxazoline group is particularly preferable, and can be prepared by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with another monomer. Addition polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like can be mentioned, and one or a mixture of two or more thereof can be used.

Among these, 2-isopropenyl-2-oxazoline is suitable because it is easily available industrially. Other monomers are not limited as long as they are copolymerizable with addition-polymerizable oxazoline group-containing monomers. For example, (meth)acrylic acid esters such as alkyl (meth)acrylates; unsaturated carboxylic acids such as acids, fumaric acid, crotonic acid, styrenesulfonic acid and salts thereof (sodium salts, potassium salts, ammonium salts, tertiary amine salts, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; Unsaturated amides such as (meth)acrylamide, N-alkyl(meth)acrylamide, N,N-dialkyl(meth)acrylamide; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether α-olefins such as ethylene and propylene; halogen-containing α,β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α,β-unsaturated aromatics such as styrene and α-methylstyrene Monomers and the like can be mentioned, and one or two or more of these monomers can be used. The above alkyl includes methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group and the like.

The isocyanate compound used as the cross-linking agent is a compound having an isocyanate derivative structure represented by isocyanate or blocked isocyanate. Examples of isocyanates include aromatic isocyanates such as tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate; Aliphatic isocyanates; aliphatic isocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; and the like are exemplified.

Polymers and derivatives of these isocyanates, such as buret products, isocyanurate products, uretdione products, and carbodiimide modified products, are also included. These may be used alone or in combination of multiple types. Among the above isocyanates, aliphatic or alicyclic isocyanates are more preferable than aromatic isocyanates in order to avoid yellowing due to ultraviolet rays.

When used in the form of blocked isocyanate, examples of blocking agents include bisulfites, phenolic compounds such as phenol, cresol, and ethylphenol, and alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol. active methylene compounds such as dimethyl malonate, diethyl malonate, methyl isobutanoylacetate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; mercaptan compounds such as butyl mercaptan and dodecyl mercaptan; ε-caprolactam, δ-valerolactam, etc. lactam compounds, diphenylaniline, aniline, amine compounds such as ethyleneimine, acetanilide, acetic acid amide acid amide compounds, formaldehyde, acetaldoxime, acetone oxime, methyl ethyl ketone oxime, cyclohexanone oxime and other oxime compounds, These may be used alone or in combination of two or more. Among the above, an isocyanate compound blocked with an active methylene-based compound is particularly preferred from the viewpoint of adhesion to the base film and wettability to the base film.

Further, the isocyanate compound may be used alone, or may be used as a mixture or combination with various polymers. In the sense of improving the dispersibility and crosslinkability of the isocyanate compound, it is also preferable to use a mixture or combination with a polyester resin or a urethane resin.

Examples of the epoxy compound used as the cross-linking agent include condensates of epichlorohydrin with ethylene glycol, polyethylene glycol, glycerin, polyglycerin, and hydroxyl groups and amino groups such as bisphenol A, and polyepoxy compounds and diepoxy compounds. , monoepoxy compounds, glycidylamine compounds, and the like. Examples of polyepoxy compounds include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris(2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether, trimethylolpropane. Polyglycidyl ether; diepoxy compounds such as neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether , polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether; monoepoxy compounds such as allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, glycidylamine compounds such as N, N, N', N '-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N-diglycidylamino)cyclohexane and the like.

The melamine compound used as the cross-linking agent is a compound having a melamine skeleton in the compound. compounds, and mixtures thereof can be used. As the alcohol used for etherification, methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butanol, isobutanol and the like are preferably used. Moreover, the melamine compound may be either a monomer or a polymer of dimers or higher, or a mixture thereof. Considering the reactivity with various compounds, the melamine compound preferably contains a hydroxyl group. Further, melamine may be partially co-condensed with urea or the like, and a catalyst may be used to increase the reactivity of the melamine compound.

The carbodiimide compound used as the cross-linking agent is a compound having one or more carbodiimide or carbodiimide derivative structures in the molecule. A polycarbodiimide compound having two or more carbodiimide structures in the molecule is preferred for better strength of the functional layer.

The carbodiimide compound used as the cross-linking agent can be synthesized by a conventionally known technique, and generally a condensation reaction of a diisocyanate compound is used. The diisocyanate compound is not particularly limited, and both aromatic and aliphatic compounds can be used. methylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, dicyclohexylmethane diisocyanate and the like.

Furthermore, in order to improve the water-solubility and water-dispersibility of the polycarbodiimide-based compound, a surfactant may be added, polyalkylene oxide, or a quaternary ammonium salt of a dialkylamino alcohol to the extent that the effects of the present invention are not lost. , hydroxyalkylsulfonate, and other hydrophilic monomers may be added.

The silane coupling compound used as the cross-linking agent is an organosilicon compound having an organic functional group and a hydrolyzable group such as an alkoxy group in one molecule. For example, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4- epoxy group-containing compounds such as ethyltrimethoxysilane; vinyl group-containing compounds such as vinyltrimethoxysilane and vinyltriethoxysilane; styryl group-containing compounds such as p-styryltrimethoxysilane and p-styryltriethoxysilane; 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, 3-(meth)acryloxypropylmethyldiethoxysilane, etc. (Meth) acrylic group-containing compounds; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)- 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N Amino group-containing compounds such as -(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane; tris(trimethoxysilylpropyl) Isocyanurate, isocyanurate group-containing compounds such as tris(triethoxysilylpropyl) isocyanurate; and mercapto group-containing compounds such as ethoxysilane.

Among the above compounds, epoxy group-containing silane coupling compounds, double bond-containing silane coupling compounds such as vinyl groups and (meth)acrylic groups, and amino group-containing compounds are preferred from the viewpoint of the strength of the functional layer and adhesion to the base film. Silane coupling compounds are more preferred.

The cross-linking agent contained in the functional layer usually exists in a state of being reacted with the polymer or the cross-linking agent itself during the drying process or the film-forming process. Therefore, the functional layer in the present laminated white film is present as an unreacted product of these cross-linking agents, a compound after the reaction, or a mixture thereof (compound derived from the cross-linking agent).

The lower limit of the content of the cross-linking agent in the functional layer is usually 0% by weight or more, preferably 3% by weight or more, more preferably 5% by weight or more, still more preferably 8% by weight or more, and particularly preferably 10% by weight or more. . The upper limit is usually 80% by weight or less, preferably 70% by weight or less, more preferably 60% by weight or less, even more preferably 50% by weight or less, and particularly preferably 40% by weight or less. By using it in the above range, it is possible to improve the strength of the functional layer, and also improve the adhesion with the base film and improve the wettability to the base film when providing the functional layer by coating. Appearance tends to be easier to achieve.

(other ingredients)
Particles can be used in combination in the functional layer for blocking or improving slipperiness within the scope of the present invention. Furthermore, it is also possible to use antifoaming agents, coatability improvers, thickeners, organic lubricants, ultraviolet absorbers, antioxidants, foaming agents, etc. in the functional layer.

(Thickness of functional layer)
The film thickness of the functional layer is usually 0.001 to 3 μm, preferably 0.005 to 1 μm, more preferably 0.01 to 0.5 μm, still more preferably 0.02 to 0.3 μm, most preferably 0.03 ~0.2 μm. By setting the film thickness of the functional layer within the above range, it tends to be easy to achieve both good antistatic performance and mold release performance.

(Arrangement of functional layers)
The functional layer can be provided on one side of the polyester film or on both sides of the polyester film.
In the case of providing on both sides, both sides of the film can be used as a recording material, and there are advantages such as improved handling properties of the film.

(Antistatic performance of functional layer)
As for the antistatic performance of the functional layer, the surface resistance value is usually 1×10 ¹³ Ω or less, preferably 1×10 ¹² Ω or less, more preferably 5×10 ¹¹ Ω or less, further preferably 1×10 ¹¹ Ω or less. , and particularly preferably 5×10 ¹⁰ Ω or less. Within the above range, the film tends to be effective in preventing sticking between films and in preventing adhesion of dust and the like. For this reason, when the toner image is transferred onto the recording material by electrophotography, thermal transfer, etc., when using it as a recording material for copying paper or printer paper, it is difficult to transfer the toner image to the recording material. It is possible to prevent double feeding in printing and to prevent sheets from sticking to each other when handling sheets.

<Method for producing laminated white film>
The method for producing the present laminated white film will be specifically described below. However, the present invention is not particularly limited to the following examples as long as the gist of the present invention is satisfied.

First, dried or undried blended raw materials are supplied to a melt extruder by a known method, heated to a temperature equal to or higher than the melting point of each polymer, and melt-kneaded. The molten polymer is then directed to a die to produce a molten sheet.
In the case of producing a polyester film laminated with two or more layers, a raw material blended for each layer, dried or undried by a known method, is supplied to each melt extruder, and the temperature is above the melting point of each polymer. to melt and knead. The molten polymer for each layer is then directed, typically through a multi-manifold or feedblock, to a die for lamination.
The molten sheet extruded from the die is then quenched and solidified on a rotating cooling drum to a temperature below the glass transition temperature to obtain an unoriented sheet in a substantially amorphous state. In this case, in order to improve the flatness of the sheet, it is preferable to increase the adhesion between the sheet and the rotating cooling drum, and the electrostatic application adhesion method and/or the liquid application adhesion method are preferably employed.

The sheet obtained as described above is stretched to form a film. The ultrafine closed cavities contained in the polyester film are produced by such stretching.

Specifically, the unstretched sheet is preferably stretched 2.5 to 5 times in the longitudinal direction (longitudinal direction) at 70 to 150 ° C. to form a longitudinal uniaxially stretched film, and then stretched in the width direction ( The film is stretched 3 to 5 times at 70 to 160° C. in the transverse direction), usually 200 to 250° C., preferably 210 to 240° C., more preferably 215 to 240° C., usually 5 to 600 seconds, preferably 8 It is preferable to perform the heat treatment for up to 300 seconds.
By adjusting the heat treatment temperature within this temperature range, the degree of solubility of the polymer incompatible with the polyester can be adjusted, and the roughness of the film surface can be adjusted.

Various conditions of the heat treatment process affect not only the heat shrinkage of the film but also the surface arithmetic mean roughness (SRa) of the film. That is, by setting the temperature to a high temperature within the above range, the ultrafine voids formed by the polymer incompatible with the polyester present on the surface or in the case of a laminated structure are dissolved. By moderately reducing the surface roughness, it becomes possible to easily peel and remove characters and images such as a toner containing a thermoplastic resin and/or an image forming substance formed on the film surface by printing or printing. . As a result, the film can be repeatedly used as a recording material for copy paper and printer paper.

After the heat treatment step, a method of relaxing 2 to 20% in the longitudinal direction and/or the transverse direction in the highest temperature zone of the heat treatment and/or the cooling zone at the exit of the heat treatment is preferred. In addition, re-stretching in the longitudinal direction and re-stretching in the lateral direction can be added as necessary.

[Method for producing functional layer]
A functional layer is laminated on at least one side of the polyester film obtained by the manufacturing method described above.
The functional layer can be provided by various known methods such as a coating method, a coextrusion method, and a transfer method. Among them, the one by coating is preferable from the viewpoint of efficient production and imparting performance.

Examples of the coating method include gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roll coating, squeeze coating, impregnation coating, kiss coating, and spraying. Conventionally known coating methods such as coating, calendar coating, and extrusion coating can be used.
It may be provided by in-line coating, in which the film surface is treated during the film-forming process of the polyester film, or may be applied off-line coating, in which the film is once produced outside the system. More preferably, it is formed by in-line coating.

In-line coating is a method of coating in the process of polyester film production, specifically, a method of coating at any stage from melt extrusion of polyester to stretching, heat setting and winding. Usually, it is coated on an unstretched sheet obtained by melting and quenching, a stretched uniaxially stretched film, a biaxially stretched film before heat setting, or a film after heat setting and before winding. Although not limited to the following, for example, in sequential biaxial stretching, a method of coating a uniaxially stretched film stretched in the longitudinal direction (longitudinal direction) and then stretching in the width direction (horizontal direction) is excellent. According to such a method, film formation and functional layer formation can be performed at the same time, which is advantageous in terms of manufacturing cost. In addition, since stretching is performed after coating, the thickness of the functional layer can be changed by the stretching ratio. , thin film coating can be performed more easily than offline coating. Further, by providing the functional layer on the film before stretching, the functional layer can be stretched together with the base film, thereby firmly adhering the functional layer to the base film.
Furthermore, in the production of biaxially stretched polyester film, the film can be restrained in the vertical and horizontal directions by holding the ends of the film with a clip or the like while the film is stretched. High temperature can be applied while maintaining the properties. Therefore, since the heat treatment applied after coating can be performed at a high temperature that cannot be achieved by other methods, the film-forming property of the functional layer is improved, and the functional layer and the base film can be adhered more firmly. Furthermore, a strong functional layer can be obtained, the functional layer can be prevented from coming off, and antistatic performance and release performance can be improved.

As a method for forming the functional layer, the above-mentioned series of compounds are used as a solution or a dispersion in a solvent, and a liquid adjusted to a solid content concentration of about 0.1 to 80% by weight is coated on the polyester film. It is preferred to produce a laminated white film. Especially when it is provided by in-line coating, it is more preferable to use an aqueous solution or a water dispersion. For the purpose of improving dispersibility in water and film-forming properties, the coating liquid may contain a small amount of an organic solvent. In addition, only one type of organic solvent may be used, or two or more types may be used as appropriate.

The drying and curing conditions for forming the functional layer are not particularly limited, but in the case of the coating method, the drying temperature of the solvent such as water used in the coating liquid is usually 70 to 150° C., preferably is 80 to 130°C, more preferably 90 to 120°C. The drying time is generally 3 to 200 seconds, preferably 5 to 120 seconds.
Also, in order to improve the strength of the functional layer, it is preferable that the film manufacturing process undergoes a heat treatment process usually at 150 to 270.degree. C., preferably 170 to 250.degree. C., more preferably 180 to 240.degree. The time for the heat treatment step is 5 to 600 seconds, preferably 8 to 300 seconds, as a guideline.

Moreover, you may combine heat processing and active-energy-ray irradiation, such as ultraviolet irradiation, as needed. The polyester film constituting the laminated white film may be previously subjected to surface treatment such as corona treatment or plasma treatment.

<Image forming substance, etc.>
In this laminated white film, characters and images containing thermoplastic resin such as toner and/or image-forming substance can be provided on the functional layer.

Here, characters and images can be provided by a conventionally known technique, and can be obtained by printing or printing with a copying machine, printer, or the like.
On the other hand, conventionally known materials can also be used for thermoplastic resins used in toners and/or image forming substances.
There are no restrictions on the imaging substance. That is, the above-mentioned "toner and/or image-forming substance, etc." generally includes all substances capable of forming an image on a recording material, and may be in any form of solid particles, suspension, solution, or the like. There may be.
Moreover, there are no restrictions on the coloring agent, and any of pigments, dyes, colored compounds, and the like can be used. Among them, a fine toner obtained by dispersing a pigment in a thermoplastic resin is preferable.

<Resin layer>
The laminated white film can further have a resin layer on the toner and/or the image forming substance.
The resin layer may be provided so that characters and images can be peeled off from the film together with the resin layer in order to reuse the laminated white film.

As the resin layer, a conventionally known material can be used, and a curable layer made of a curable resin composition is preferable.
Examples of the curable resin layer include a thermosetting resin layer made of a resin composition that is cured by heating, and an active energy ray-curable resin layer made of a resin composition that is cured by irradiation with an active energy ray. Among them, the active energy ray-curable resin layer is preferable from the viewpoint that it is easy to peel and remove without leaving any characters or images.

Examples of the active energy ray-curable resin layer include an ultraviolet-curable resin layer, an electron beam-curable resin layer, a visible light-curable resin layer, and the like. Considering ease of handling and curability, it is preferably an ultraviolet curable resin layer. An example of the active energy ray-curable resin layer is a hard coat layer.

The material used for the active energy ray-curable resin layer is not particularly limited. Examples thereof include cured products of monofunctional (meth)acrylates, polyfunctional (meth)acrylates, and reactive silicon compounds such as tetraethoxysilane. Among these, from the viewpoint of achieving both productivity and hardness, it is particularly preferable to use a polymerized and cured product of a composition containing an active energy ray-curable (meth)acrylate.

A composition containing an active energy ray-curable (meth)acrylate is not particularly limited. For example, mixtures of one or more of known monofunctional (meth)acrylates, bifunctional (meth)acrylates, and polyfunctional (meth)acrylates, commercially available active energy ray-curable hard coating resin materials, or these In addition, other components may be further added within the range not impairing the purpose of the present embodiment.

The active energy ray-curable monofunctional (meth)acrylate is not particularly limited. For example, alkyl (meth)acrylate such as methyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc. meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, etc. hydroxyalkyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypropyl (meth)acrylate ) acrylate, alkoxyalkyl (meth) acrylates such as ethoxypropyl (meth) acrylate, aromatic (meth) acrylates such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypropyl (meth) acrylate, diaminoethyl (meth) acrylate, etc. ) acrylate, amino group-containing (meth)acrylate such as diethylaminoethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, ethylene oxide-modified such as phenylphenol ethylene oxide-modified (meth)acrylate (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acrylic acid and the like.

The active energy ray-curable bifunctional (meth)acrylate is not particularly limited. For example, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, tricyclodecanedi alkanediol di(meth)acrylates such as methylol di(meth)acrylate; bisphenol-modified di(meth)acrylates such as bisphenol A ethylene oxide-modified di(meth)acrylate; bisphenol F ethylene oxide-modified di(meth)acrylate; (Meth)acrylate, polypropylene glycol di(meth)acrylate, urethane di(meth)acrylate, epoxy di(meth)acrylate and the like.

Active energy ray-curable polyfunctional (meth)acrylates are not particularly limited, and examples thereof include dipentaerythritol hexa(meth)acrylate, pentaerythritol tetra(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate. , pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, isocyanuric acid ethylene oxide-modified tri(meth)acrylate, ε-caprolactone-modified tris(acryloxyethyl)isocyanurate, and other isocyanuric acid-modified tri(meth) Urethane acrylates such as acrylate, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, and dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer.

Other components contained in the composition containing the active energy ray-curable (meth)acrylate are not particularly limited. Examples thereof include inorganic or organic fine particles, polymerization initiators, polymerization inhibitors, antioxidants, antistatic agents, dispersants, surfactants, light stabilizers and leveling agents. Moreover, in the case of drying after film formation in the wet coating method, an arbitrary amount of solvent can be added.

For indoor use such as offices, it is preferably solvent-free. As the resin (resin liquid) for forming the resin layer, the solvent content is preferably 10% by weight or less, more preferably 5% by weight or less, even more preferably 3% by weight or less, and particularly preferably 1% by weight or less. and most preferably solvent free (intentionally free).

Methods for forming the resin layer include general wet coating methods such as roll coating and die coating, and extrusion methods. The formed resin layer can be heated or irradiated with an active energy ray such as an ultraviolet ray or an electron beam as necessary to carry out a curing reaction.

<Explanation of terms, etc.>
In the present invention, when described as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, "X or more and Y or less" and "preferably larger than X" or "preferably Y It also includes the meaning of "less than".
In addition, when described as "X or more" (X is an arbitrary number), it includes the meaning of "preferably greater than X" unless otherwise specified, and is described as "Y or less" (Y is an arbitrary number). If not otherwise specified, it also includes the meaning of "preferably smaller than Y".

EXAMPLES The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples as long as the gist thereof is not exceeded. Moreover, the measuring method used in the present invention is as follows. Various physical properties, methods for measuring them, and definitions in the present invention are as follows.

<Measurement method>
(1) Intrinsic viscosity of polyester Accurately weigh 1 g of polyester from which other components such as polymer components and particles incompatible with polyester have been removed, and add 100 ml of a mixed solvent of phenol/tetrachloroethane = 50/50 (weight ratio). and measured at 30°C.

(2) Melt flow index (MFI)
According to JIS K7210-1995, amorphous polyolefin was measured at 275°C and 21.2N, and polypropylene was measured at 230°C and 21.2N. A higher value indicates a lower melt viscosity of the polymer.

(3) Arithmetic mean roughness (SRa)
The film surface is measured using a non-contact surface/layer cross-sectional shape measurement system VertScan (registered trademark) R550GML manufactured by Ryoka Systems Co., Ltd., CCD camera: SONY HR-50 1/3 ', objective lens: 20x, mirror Cylinder: 1X Body, Zoom lens: No Relay, Wavelength filter: 530 white, Measurement mode: Wave, measure an area of 640 μm × 480 μm, use the output by 4th order polynomial correction, and calculate the arithmetic mean roughness SRa value It was obtained by averaging 10 points.

(4) Average Particle Size Particle size was measured by a sedimentation method based on Stokes' law of resistance using a centrifugal sedimentation particle size distribution analyzer SA-CP3 manufactured by Shimadzu Corporation. The average particle size was obtained by using the value of 50% of the cumulative (volume basis) in the equivalent spherical distribution of the particles obtained by the measurement.

(5) Film thickness of functional layer The surface of the functional layer was dyed with RuO4 and embedded in epoxy resin. After that, the section prepared by the ultra-thin section method was stained with RuO, and the cross section of the functional layer was observed using a transmission electron microscope (H-7650 manufactured by Hitachi High-Technologies Corporation, accelerating voltage 100 kV) to measure the film thickness. .

(6) Number average molecular weight Measured using gel permeation chromatography (HLC-8120GPC manufactured by Tosoh Corporation). The number average molecular weight was calculated in terms of polystyrene.

(7) Heat Shrinkage A sample was treated for 30 minutes in an oven maintained at 150° C. without tension, and the length of the sample before and after was measured to calculate the heat shrinkage using the following equation.
Heat shrinkage rate (%) = {(L0-L1)/L0} x 100
(In the above formula, L0 is the sample length before heat treatment, and L1 is the sample length after heat treatment)
Five points were measured in the longitudinal direction (MD) and the width direction (TD) of the film, and the average value for each direction was obtained.

(8) Surface resistance value Using a high resistance measuring instrument manufactured by Hewlett-Packard Japan: HP4339B and a measuring electrode: HP16008B, the polyester film was sufficiently humidified in a measurement atmosphere of 23 ° C. and 50% RH, and an applied voltage of 100 V was applied. After 1 minute, the surface resistance of the functional layer was measured.

(9) Hunter whiteness Using a colorimeter NDH-1001DP (C light source, 2 ° field of view) manufactured by Nippon Denshoku Industries Co., Ltd., according to the method of JIS P8123-1961, Hunter whiteness when a single film is used ( Wb) was measured. The back surface of the film was pressed with a black plate.

(10) b value (reflection method)
Using a colorimeter NDH-1001DP (C light source, 2° field of view) manufactured by Nippon Denshoku Industries Co., Ltd., the b value of a single film was measured according to the method of JIS Z-8722, 8730. The back surface of the film was pressed with a black plate.

(11) Opacity (OD)
A Macbeth densitometer TD-904 was used to measure the transmission density under white light. Measurement was performed at 5 points, and the average value was taken as the OD value. A larger value indicates a lower light transmittance.

(12) Apparent density (g/cm ³ )
A square sample of 10 cm x 10 cm was cut out from an arbitrary portion of the film, and the thickness of the sample was evenly measured at 9 points with a micrometer. From the average value and the weight of the film, the weight per unit volume was calculated as the apparent density. The number of measurements was 5, and the average value was used.

(13) Thickness of Laminated White Film A piece of film was fixed and molded with an epoxy resin, cut with a microtome, and the cross section of the film was observed with a transmission electron microscope. Among the cross sections, two interfaces are observed by light and shade almost parallel to the film surface. The distance between the two interfaces and the film surface was measured from 10 photographs, and the average value was taken as the thickness of the laminated white film.

(14) Appropriate image quality by electrophotographic printing Ricoh Co., Ltd. MFP: imagioMPC5001it, a film (sheet) cut to A4 size is fed, and a full-color test image on which an image forming material is printed by photo printing is printed. Obtained. Image quality was evaluated as follows.

(Evaluation criteria)
A: High-definition, high-quality image quality with no wrinkles on the film B: Part of the image quality is slightly blurred, but there is no practical problem C: Wrinkles on the film, image quality is unclear overall inferior in terms of

(15) Character and image (toner image) separation and removal suitability On the film surface on which the image forming substance obtained in (14) is fixed, 95 parts by weight of an ultraviolet curable resin (2-hydroxy-3-phenoxypropyl acrylate), A mixture of 5 parts by weight of a photopolymerization initiator (trade name: Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) is uniformly applied, a glass plate is placed on the mixture, and ultraviolet rays are irradiated from above to cure the ultraviolet rays. A resin layer was formed. After that, the glass plate and the film were separated. At this time, the formed ultraviolet curable resin layer adheres to the glass plate side, and can transfer and hold characters and images formed by the toner and/or the image forming substance formed on the film surface. At this time, the following evaluations were made with respect to the peeled-off state of characters and images on the film surface.

(Evaluation criteria)
A: The image-forming substance on the film surface can be completely removed, and the film can be used repeatedly as copying paper.
B: A small amount of the image forming material remains on the film surface, but it can be used repeatedly as copying paper and poses no practical problem.
C: Most of the image-forming substance remained on the film surface, and the film could not be used repeatedly as copying paper.

(16) Printing transportability Ricoh Co., Ltd. MFP: imagioMPC5001it, 100 sheets of film (sheets) cut to A4 size are fed, and the film of the MFP when continuous printing of 100 photo prints is performed. (Sheet) Conveyability was evaluated as follows.

(Evaluation criteria)
A: There is no film (sheet) jamming in the multifunction machine. In addition, it was confirmed on the output tray of the multifunction printer that each sheet of printed film (sheet) was transported independently without any occurrence of double feeding.
B: Double feeding of printed films (sheets) sometimes occurs, but it is confirmed at the output tray of the multifunction device that there is no jamming of the film (sheet) in the multifunction device and continuous printing is possible. .
C: Films (sheets) stick to each other, making several films clumped together, making it impossible for the MFP to transport the films (sheets), or causing frequent film (sheet) jams within the MFP, resulting in continuous printing. Unable to print, or barely able to print, but image quality is blurry and overall inferior.

(17) Writability
Five straight lines were drawn at intervals of 1 mm with a pencil of hardness H of Uni manufactured by Mitsubishi Pencil Co., Ltd., and the following evaluations were made by visual observation.

(Evaluation criteria)
A: Individual straight lines can be distinguished.
B: The color of the lines is light, and individual lines are difficult to distinguish.
C: A straight line cannot be drawn.

(18) Appearance of Functional Layer The laminated white film was observed under a fluorescent lamp, and the appearance of the functional layer was visually observed and evaluated as follows.

(Evaluation criteria)
A: Uniform appearance with no defects in the functional layer B: Defects in part of the functional layer C: Defects in most of the functional layer

<Function layer>
Compounds constituting the functional layer are as follows.

・Antistatic agent (compound having an ammonium group): (IA)
Polymer diallyldimethylammonium chloride/dimethylacrylamide/N-methylolacrylamide = 90/5/5 (mol%), having a pyrrolidinium ring in the main chain and polymerized according to the following composition. Number average molecular weight 30,000.

・Antistatic agent (compound having an ammonium group): (IB)
A polymer compound having a number-average molecular weight of 50,000 and having a counter ion of methanesulfonate ion, which consists of structural units represented by the following formula (2).

・Mold release agent (long-chain alkyl group-containing compound): (IIA)
200 parts by weight of xylene and 600 parts by weight of octadecyl isocyanate were added to a four-necked flask and heated while stirring. When xylene started to reflux, 100 parts by weight of polyvinyl alcohol having an average degree of polymerization of 500 and a degree of saponification of 88 mol % was added little by little at intervals of 10 minutes over about 2 hours. After the addition of polyvinyl alcohol was completed, the mixture was further refluxed for 2 hours to terminate the reaction. When the reaction mixture was cooled to about 80° C. and added to methanol, the reaction product precipitated as a white precipitate. After repeating the operation of adding methanol again for precipitation several times, the precipitate was washed with methanol, dried and pulverized.

・Releasing agent (condensed silicone containing polyether group): (IIB)
A polyether group-containing silicone (silicone siloxane Assuming that the number of bonds is 1, the molar ratio of the ether bonds in the polyether group is 0.07). Low molecular weight components with a number average molecular weight of 500 or less are 3% by weight, and vinyl groups (vinylsilane) bonded to silicon and hydrogen groups (hydrogensilane) are not present. The present compound is prepared by blending sodium dodecylbenzenesulfonate at a weight ratio of 0.25 to 1 for polyether group-containing silicone, and dispersing the mixture in water.

・Mold release agent (wax): (IIC)
300 g of oxidized polyethylene wax having a melting point of 105° C., an acid value of 16 mg KOH/g, a density of 0.93 g/mL and a number average molecular weight of 5000, and ion-exchanged water of 650 g are placed in an emulsification facility with a capacity of 1.5 L equipped with a stirrer, thermometer, and temperature controller. 50 g of decaglycerin monooleate surfactant and 10 g of 48% by weight potassium hydroxide aqueous solution were added and replaced with nitrogen. and cooled to 40°C.

・Acrylic resin: (III)
Emulsion polymer of ethyl acrylate/n-butyl acrylate/N-methylolacrylamide/acrylic acid = 88/10/1/1 (% by weight) (emulsifier: nonionic surfactant)

・Crosslinking agent (oxazoline compound): (IVA)
Acrylic polymer Epocross (registered trademark) having an oxazoline group and a polyalkylene oxide chain (oxazoline group weight = 4.5 mmol / g, manufactured by Nippon Shokubai Co., Ltd.)

・Crosslinking agent (isocyanate compound): (IVB)
1000 parts by weight of hexamethylene diisocyanate was stirred at 60° C. and 0.1 part by weight of tetramethylammonium caprylate was added as a catalyst. After 4 hours, 0.2 parts by weight of phosphoric acid was added to stop the reaction, and an isocyanurate-type polyisocyanate composition was obtained. 100 parts by weight of the resulting isocyanurate-type polyisocyanate composition, 42.3 parts by weight of methoxypolyethylene glycol having a number average molecular weight of 400, and 29.5 parts by weight of propylene glycol monomethyl ether acetate were charged and maintained at 80° C. for 7 hours. Thereafter, while maintaining the temperature of the reaction solution at 60° C., 35.8 parts by weight of methyl isobutanoylacetate, 32.2 parts by weight of diethyl malonate, and 0.88 parts by weight of a 28% by weight methanol solution of sodium methoxide were added and maintained for 4 hours. bottom. An active methylene-blocked polyisocyanate obtained by adding 58.9 parts by weight of n-butanol, maintaining the temperature of the reaction solution at 80° C. for 2 hours, and then adding 0.86 parts by weight of 2-ethylhexyl acid phosphate.

・Crosslinking agent (hexamethoxymethylolmelamine): (IVC)

[Example 1]
80 parts by weight of polyethylene terephthalate chips with an intrinsic viscosity of 0.67 dl/g and 20 parts by weight of crystalline polypropylene homopolymer chips with a melt flow index of 10 ml/10 min for the intermediate layer, set at 280° C. Main vented biaxial 15 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.66 dl/g containing 50% by weight of titanium oxide particles having an average particle diameter of 0.32 μm and crystals having a melt flow index of 8 ml/10 minutes were placed in an extruder for the surface layer. 15 parts by weight of flexible polypropylene homopolymer chips, 10 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.66 dl/g containing 3.5% by weight of silica particles having an average particle size of 4.1 μm, and an intrinsic viscosity of 0.69 dl/g 60 parts by weight of polyethylene terephthalate chips were fed into a sub-vented twin-screw extruder set at 280°C. Through a gear pump and a filter, the polymer from the main extruder is the middle layer, and the polymer from the sub-extruder is the surface layer on both sides of the middle layer. It was extruded through a die and quenched and solidified on a cooling roll whose surface temperature was set to 30° C. using an electrostatic contact method to obtain a substantially amorphous sheet having a thickness of 887 μm.

After the obtained amorphous sheet was stretched 3.1 times in the longitudinal direction at 92° C., water-based coating liquid 1 shown in Table 4 below was applied to both sides of the longitudinally stretched film to obtain the thickness of the functional layer (after drying). is 0.10 μm, guided to a tenter, then stretched 3.8 times at 120° C. in the transverse direction, heat-treated at 235° C. for 10 seconds, relaxed 10% in the transverse direction to 6 μm ( Surface layer)/62 μm (intermediate layer)/6 μm (surface layer) to obtain a laminated white film with a total thickness of 74 μm.
Evaluation of the obtained laminated white film revealed that the image quality, characters, image peeling and removal suitability, print conveyability, writability, and appearance of the functional layer were all good. Properties of this film are shown in Tables 4 and 8 below.

[Examples 2 to 4]
A laminated white film was obtained in the same manner as in Example 1 except that the film thickness (after drying) of the functional layer was changed as shown in Table 1.
As shown in Tables 4 and 8 below, the resulting laminated white film had an appropriate image quality and good writability.

[Examples 5 to 14]
A laminated white film was obtained in the same manner as in Example 1, except that the composition of the coating liquid for the functional layer was changed. The manufacturing conditions in each example are shown in Table 1 below, and the composition of the coating solution for the functional layer is shown in Table 7 below.
As shown in Tables 4 and 8 below, the resulting polyester film had good image quality and good writability.

[Example 15]
40 parts by weight of polyethylene terephthalate chips with an intrinsic viscosity of 0.63 dl/g, 15 parts by weight of crystalline polypropylene homopolymer chips with a melt flow index of 7 ml/10 minutes, the lugs generated during the production of polyester in Example 1 and master roll lugs A laminated white film having a thickness of 75 μm was obtained in the same manner as in Example 1, except that a mixed raw material obtained by mixing 45% by weight of a recycled product from the same company as the intermediate layer was used. The thickness of each layer of the resulting film was 6 μm/63 μm/6 μm. The total amount of polypropylene derived from the crystalline polypropylene homopolymer chips and from the recycled product amounts to 24% by weight.
Evaluation of the obtained laminated white film revealed that the image quality was good, letters and images were peeled off and removed, print transportability, writability, and appearance of the functional layer were all good. Properties of this film are shown in Tables 4 and 8 below.

[Examples 16-18]
A laminated white film was obtained in the same manner as in Example 15 except that the film thickness (after drying) of the functional layer was changed as shown in Table 1. As shown in Tables 4 and 8 below, the resulting laminated white film had an appropriate image quality and good writability.

[Examples 19 to 27]
A laminated white film was obtained in the same manner as in Example 15, except that the composition of the coating liquid for the functional layer was changed. The manufacturing conditions in each example are shown in Table 1 below, and the composition of the coating solution for the functional layer is shown in Table 7 below.
As shown in Tables 4 and 8 below, the resulting polyester film was good in image quality, character and image peeling/removal suitability, print transportability and writing property.

[Example 28]
3 parts by weight of polyethylene terephthalate chips with an intrinsic viscosity of 0.66 dl/g, 10 parts by weight of crystalline polypropylene homopolymer chips with a melt flow index of 10 ml/10 minutes, lugs generated during polyester production in Example 1 and master roll lugs A laminated white film having a thickness of 75 μm was obtained in the same manner as in Example 1, except that a mixed raw material obtained by mixing 87% by weight of a recycled product from the same company as the intermediate layer was used. The thickness of each layer of the resulting film was 6 μm/63 μm/6 μm.
Evaluation of the obtained laminated white film revealed that characters and images were peelable and removable, print transportability, writability, and appearance of the functional layer were all good. Properties of this film are shown in Tables 4 and 8 below.

[Examples 29-31]
A laminated white film was obtained in the same manner as in Example 28 except that the film thickness (after drying) of the functional layer was changed as shown in Table 1. As shown in Tables 4 and 8 below, the resulting laminated white film had an appropriate image quality and good writability.

[Examples 32-40]
A laminated white film was obtained in the same manner as in Example 28, except that the composition of the coating liquid for the functional layer was changed. The manufacturing conditions in each example are shown in Table 1 below, and the composition of the coating solution for the functional layer is shown in Table 7 below.
As shown in Tables 4 and 8 below, the obtained polyester film was excellent in character and image peelability, print transportability, and writability.

[Example 41]
15 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.65 dl/g containing 50% by weight of titanium oxide particles having an average particle size of 0.32 μm, and crystalline polypropylene homopolymer chips having a melt flow index of 8 ml/10 minutes1. 3 parts by weight, 1.6 parts by weight of polyethylene terephthalate chips with an intrinsic viscosity of 0.66 dl/g containing 0.5% by weight of silica particles having an average particle size of 4.1 μm, and polyethylene with an intrinsic viscosity of 0.68 dl/g A laminated white film having a thickness of 75 μm was obtained in the same manner as in Example 15 except that 82.1 parts by weight of terephthalate chips were used as the surface layer. The thickness of each layer of the resulting film was 6 μm/63 μm/6 μm.
Evaluation of the obtained laminated white film revealed that the image quality was good, characters and images were peeled off and removed, print transportability and appearance of the functional layer were all good. Properties of this film are shown in Tables 5 and 9 below.

[Examples 42-44]
A laminated white film was obtained in the same manner as in Example 41 except that the film thickness (after drying) of the functional layer was changed as shown in Table 2. As shown in Tables 5 and 9 below, the resulting laminated white film had good image quality and good writability.

[Examples 45-53]
A laminated white film was obtained in the same manner as in Example 41, except that the composition of the coating liquid for the functional layer was changed. The manufacturing conditions in each example are shown in Table 2 below, and the composition of the coating solution for the functional layer is shown in Table 7 below.
As shown in Tables 5 and 9 below, the obtained polyester film was good in image quality, characters, image peeling and removal, and print transportability.

[Example 54]
15 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.65 dl/g containing 50% by weight of titanium oxide particles having an average particle size of 0.32 μm, 0.5 parts by weight of crystalline polypropylene homopolymer chips having a melt flow index of 8 ml/10 min. 5 parts by weight, 10 parts by weight of polyethylene terephthalate chips with an intrinsic viscosity of 0.66 dl/g containing 3.5% by weight of silica particles having an average particle size of 4.1 μm, 10 parts by weight of polyethylene terephthalate chips with an intrinsic viscosity of 0.68 dl/g A laminated white film having a thickness of 75 μm was obtained in the same manner as in Example 15, except that 74.5 parts by weight was used as the surface layer and only one side was coated in the coating step of the coating liquid after longitudinal stretching. The thickness of each layer of the resulting film was 6 μm/63 μm/6 μm.
Regarding the obtained laminated white film, each evaluation of image quality adequacy, letter/image peeling/removal adequacy and writability was carried out on the side to which the coating liquid was not applied. Appropriate image quality, print conveyability and appearance of the functional layer were good. Properties of this film are shown in Tables 5 and 9 below.

[Example 55]
15 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.66 dl/g containing 50% by weight of titanium oxide particles having an average particle size of 0.12 μm, and 15 parts by weight of crystalline polypropylene homopolymer chips having a melt flow index of 8 ml/10 min. 10 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.66 dl/g containing 3.5% by weight of silica particles having an average particle diameter of 4.1 μm, 60 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.69 dl/g A laminated white film having a thickness of 75 μm was obtained in the same manner as in Example 15, except that it was used as a part. The thickness of each layer of the resulting film was 6 μm/63 μm/6 μm.
The resulting laminated white film was evaluated to find that characters and images were suitable for peeling and removal, and that the printing transportability, writing ability, and appearance of the functional layer were all good. Properties of this film are shown in Tables 5 and 9 below.

[Examples 56-58]
A laminated white film was obtained in the same manner as in Example 55 except that the film thickness (after drying) of the functional layer was changed as shown in Table 2.
As shown in Tables 5 and 9 below, the resulting laminated white film had good image quality and good writability.

[Examples 59-67]
A laminated white film was obtained in the same manner as in Example 55, except that the composition of the coating solution for the functional layer was changed. The manufacturing conditions in each example are shown in Table 2 below, and the composition of the coating solution for the functional layer is shown in Table 7 below.
As shown in Tables 5 and 9 below, the resulting polyester film was suitable for peeling and removing letters and images, and had good print transportability and writability.

[Example 68]
15 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.66 dl/g containing 50% by weight of titanium oxide particles having an average particle size of 0.32 μm, and 15 parts by weight of crystalline polypropylene homopolymer chips having a melt flow index of 8 ml/10 min. In the same manner as in Example 15, except that 70 parts by weight of polyethylene terephthalate chips having an intrinsic viscosity of 0.66 dl / g containing 5.0% by weight of silica particles having an average particle diameter of 11.1 μm were used as the surface layer. A laminated white film with a thickness of 75 μm was obtained. The thickness of each layer of the resulting film was 6 μm/63 μm/6 μm.
Evaluation of the obtained laminated white film revealed that the appropriate image quality, print transportability, writability and appearance of the functional layer were all good. Properties of this film are shown in Tables 5 and 9 below.

[Example 69]
A laminated white film having a thickness of 75 μm and a thickness of each layer of 6 μm/63 μm/6 μm was obtained in the same manner as in Example 15, except that the heat treatment was performed at a heat treatment temperature of 201° C. for 10 seconds in the heat treatment step in the film forming process. rice field.
The resulting laminated white film was evaluated to find that the print transportability, writability, and appearance of the functional layer were all good. Properties of this film are shown in Tables 5 and 9 below.

[Comparative Example 1]
A polyester film was obtained in the same manner as in Example 1, except that the crystalline polypropylene homopolymer chips were replaced with polyethylene terephthalate chips and the functional layer was not provided. As shown in Tables 6 and 10, the resulting polyester film was poor in all of the properties of image quality suitability, characters, image peeling and removal suitability, print transportability, and writability.

[Comparative Example 2]
A laminated white film was obtained in the same manner as in Example 1, except that the composition of the coating liquid for the functional layer was changed. The manufacturing conditions of Comparative Example 2 are shown in Table 6 below, and the composition of the coating solution for the functional layer is shown in Table 7 below.
As shown in Tables 6 and 10 below, the resulting polyester film was poor in image quality suitability and print transportability.

Claims (12)

A functional layer containing an antistatic agent is provided on at least one side of a polyester film having an apparent density of 0.7 to 1.3 g/cm ³ and a thickness of 10 to 1000 μm. / or a layer comprising an image-forming substance and a resin layer thereon, the layer being made of an active energy ray-curable resin from which the resin layer can be peeled, and the polyester film containing a polymer incompatible with polyester. A laminated white film used as a recording material, which is an information printing medium in place of paper, and which has fine cavities formed by inclusion. 2. The laminated white film according to claim 1, wherein said polyester film has a three-layer structure consisting of both surface layers and an intermediate layer. 3. The laminated white film according to claim 2, wherein at least one surface layer of said polyester film contains a polymer incompatible with polyester. 4. The laminated white film according to claim 2, wherein the intermediate layer of the polyester film contains a polymer incompatible with polyester. The laminated white film according to any one of claims 1 to 4, wherein the polyester film contains metal compound particles. 6. The laminated white film according to claim 5, wherein the polyester film contains particles other than the metal compound particles. 7. The laminated white film according to any one of claims 1 to 6, wherein the functional layer contains a release agent. The laminated white film according to any one of claims 1 to 7, wherein the functional layer contains a cross-linking agent. The laminated white film according to any one of claims 1 to 8, which has a heat shrinkage of 2.8% or less after heating at 150°C for 30 minutes. The laminated white film according to any one of claims 1 to 9, which has an opacity (OD) of 0.30 or more. A method for producing a laminated white film according to any one of claims 1 to 10 ,
A method for producing a laminated white film, which comprises applying a coating liquid containing an antistatic agent to at least one surface of the polyester film, and then stretching the film in at least one axial direction to form a functional layer. A recording material using the laminated white film according to any one of claims 1 to 10 .