JP2008299017A - Electrophotographic recording paper and recorded matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic recording paper which is suitable for color recording, excels in recording quality, fixing property, water resistance and durability, and has consecutive printing aptitude. <P>SOLUTION: In the electrophotographic recording paper provided with a toner receiving layer containing a liposoluble polymer antistatic agent at least on one surface of a supporting body having water resistance, a surface specific resistance value of the toner receiving layer under a condition that temperature is 25°C and relative humidity is 20% is 1×10<SP>7</SP>to 9×10<SP>12</SP>Ω. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The electrophotographic recording paper of the present invention can be suitably used for color recording by an electrophotographic recording system such as a copying machine or a laser printer, has excellent recording quality such as density, color tone, gradation, etc., and has fixability, water resistance, durability. In particular, the present invention relates to an electrophotographic recording paper that is excellent in properties and has no sticking due to charging even when continuously printed.

  Recent advances in copiers and printers are remarkable, and not only in terms of price, but also in terms of performance such as recording quality and recording speed, they are dramatically improving. For this reason, printed materials such as posters, catalogs, brochures, etc. that were conventionally created by printing machines can now be created more easily and quickly while maintaining conventional recording quality using copiers and printers. became. Such recording by a copying machine or a printer can be used particularly suitably when a variety of printed materials are produced quickly.

Among various copying machines and printers, copying machines and printers employing an electrophotographic method, in particular, copying machines and laser printers using a semiconductor laser are excellent in that they can perform high-resolution and high-speed recording. Although there are problems with electrophotographic colorization, the size of the apparatus is increased because a plurality of developing devices are required, and the color tone is slightly inferior because a pigment is used as a toner color material. The problems are being solved by downsizing the apparatus and improving the materials such as toner and recording paper.
Regarding the improvement of recording paper, in electrophotographic recording paper (Patent Document 1) in which a synthetic resin film having a coating layer is laminated on at least one side of a base material layer made of a paper material having water resistance, a conventional pulp paper is used. An electrophotographic recording paper having better recording quality, fixability, water resistance and durability than the electrophotographic recording paper is devised and put into practical use.

  However, the conventional electrophotographic recording paper in which a synthetic resin film having a coating layer is laminated on at least one side of a base material layer made of a paper material having water resistance is superior in recording quality, fixability, water resistance and durability. Is excellent, but when continuously printing, the charge applied to the recording paper in the printing device cannot be removed, and if it is left as it is after printing, the recording paper will stick together. It was difficult to align (end face position). For this reason, there has been a drawback that the size and the pattern position are shifted when processing such as cutting and punching is performed after printing. Examples of recording paper that prevents charging after printing and prevents sticking between papers include those coated with an antistatic agent (see Patent Documents 2 to 4), and an antistatic agent on a toner-receptive coating layer. Have been proposed (see Patent Documents 5 to 7).

However, the proposals so far shown in Patent Documents 2 to 7 are those in which a water-soluble antistatic agent is applied alone or in which a water-soluble antistatic agent is added to a water-based paint. Even if the support itself has water resistance, the coated layer has low water resistance and cannot be used practically for outdoor use. Since these coating layers are too hydrophilic, for example, when these printed materials are immersed in water for 24 hours and then the printed surface is rubbed strongly, the toner is easily peeled off together with the coating layers. there were.
Also, in the case of using a hygroscopic type (anti-humidity dependent type) antistatic agent for electrophotographic recording paper, the relative humidity in the vicinity of the surface of the paper is reduced when overheated by the toner fixing device of the electrophotographic recording apparatus. In addition, there is a defect that the antistatic performance after printing is not stable and difficult to be exhibited, and that when paper is continuously printed in a low-humidity environment such as winter, the paper tends to stick to each other.
JP 2002-091049 A JP-A-8-297375 JP 2000-131870 A JP 2004-08389 A JP-A-8-011263 JP 2004-08389 A JP 2005-271396 A

  It is necessary to improve the problems such as excessive charging tendency, insufficient water resistance of the toner-receptive coating layer, and humidity dependency of the toner-receptive coating layer, which are observed in the conventional electrophotographic recording paper. ing. Therefore, the present invention is suitable for color recording by an electrophotographic copying machine, a laser printer, etc., and has excellent recording quality such as density, color tone, gradation, etc., and excellent fixing property, water resistance, durability, and continuous printing. Another object of the present invention is to provide an electrophotographic recording paper which is excellent in continuous printability without sticking due to charging.

As a result of diligent investigations to solve these problems, the present inventor has desired characteristics by adjusting the surface specific resistance value of the toner-receiving layer using a fat-soluble polymer antistatic agent. The present inventors have found that an electrophotographic recording sheet can be provided and have completed the present invention.
That is, the present invention relates to an electrophotographic recording paper provided with a toner receiving layer containing a fat-soluble polymer antistatic agent on at least one surface of a water-resistant support, wherein the toner receiving layer has a temperature of 25 ° C. and a relative humidity. The present invention relates to an electrophotographic recording paper having a surface specific resistance value of 1 × 10 ^{7 to} 9 × 10 ¹² Ω at 20%.

  The polymer antistatic agent used in the present invention is fat-soluble and contains an alkylene oxide group and / or a hydroxyl group and an alkali metal ion in the molecule in order to express excellent antistatic performance without depending on environmental humidity. It is preferable that More specifically, the polymer antistatic agent preferably has a (meth) acrylic polymer skeleton described in the following structural formula (1).

式中、Ｒ¹、Ｒ²は各々独立に水素原子またはメチル基を表し、Ｒ³は水素原子、塩素原子またはメチル基を表し、Ｒ⁴は炭素数１〜３０のアルキル基を表し、Ａは下記の＜１群＞から選択される１種の連結基か、下記の＜１群＞から選択される１種以上の連結基と下記の＜２群＞から選択される１種以上の連結基とが交互に結合した連結基か、または単結合を表し、
＜１群＞置換基を有していてもよい炭素数１〜６のアルキレン基、
置換基を有していてもよい炭素数６〜２０のアリーレン基、
＜２群＞−ＣＯＮＨ−、−ＮＨＣＯ−、−ＯＣＯＮＨ−、−ＮＨＣＯＯ−、
−ＮＨ−、−ＣＯＯ−、−ＯＣＯ−、−Ｏ−、
Ｍはアルカリ金属を表し、ｍは０〜３００の整数を表し、ｎは１〜３００の整数を表し、ｐは１〜１００の整数を表す。

In the formula, R ¹ and R ² each independently represents a hydrogen atom or a methyl group, R ³ represents a hydrogen atom, a chlorine atom or a methyl group, R ⁴ represents an alkyl group having 1 to 30 carbon atoms, and A represents One linking group selected from the following <Group 1> or one or more linking groups selected from the following <Group 1> and one or more linking groups selected from the following <Group 2> Represents a linking group bonded alternately or a single bond,
<Group 1> An alkylene group having 1 to 6 carbon atoms which may have a substituent,
An arylene group having 6 to 20 carbon atoms which may have a substituent,
<Group 2> —CONH—, —NHCO—, —OCONH—, —NHCOO—,
-NH-, -COO-, -OCO-, -O-,
M represents an alkali metal, m represents an integer of 0 to 300, n represents an integer of 1 to 300, and p represents an integer of 1 to 100.

In particular, if the number of carbon atoms of the alkyl group, alkylene group, or the like represented by R ⁴ or A or the alkylene oxide group is sufficiently large, the polymer antistatic agent has a fat-soluble characteristic and can be used together with a binder resin in an organic solvent. Dissolved solution paint can be applied to a support and dried to form a film to form a toner receptive layer. And durability. This excellent water resistance can be achieved by, for example, placing a printed recording paper so that it does not float in the water of a bat filled with water, immersing it in water for 24 hours, and then rubbing the recorded image with a coin or the like. Is so strong that no change is seen. Further, the polymer antistatic agent is an anionic antistatic agent having an alkali metal ion represented by M at the alkoxy terminal. When the polymer antistatic agent has alkali metal ions, the polymer antistatic agent has ionic conductivity and can exhibit excellent antistatic performance without depending on environmental humidity.

The toner receiving layer preferably contains 0.01 to 1% by weight of alkali metal ions, and the alkali metal ions are preferably lithium ions. The toner receiving layer preferably contains 1 to 50% by weight of a polymer antistatic agent and 10 to 99% by weight of a binder resin, and may further contain 70% by weight or less of pigment particles. The pigment particles may not be contained.
The binder resin is preferably composed of any of polyether urethane, polyester urethane, polyacryl urethane, acrylic acid ester copolymer, and / or a mixture thereof.
In order to improve the water resistance of not only the toner receiving layer but also the entire electrophotographic recording paper, the support is preferably also water-resistant. Specifically, the support is at least a paper material having water resistance. It is preferable to laminate a synthetic resin film on one side.

Furthermore, for the purpose of preventing yellowing of the support due to ultraviolet irradiation when the electrophotographic recording paper is used outdoors, the support is formed by laminating an ultraviolet blocking layer between a water-resistant paper material and a synthetic resin film. It is preferable.
The paper material having water resistance is preferably a paper material having a low water absorption within a range of 0 to 50 g / m ^{2 in} water absorption according to the Cobb method based on JIS-P-8140: 1998. Processed paper selected from the group consisting of photosensitive paper base, photographic paper base, resin-impregnated paper, resin-coated paper, sulfuric acid paper, pseudosulfuric paper, water-resistant paper, oil-proof paper, waterproof paper, or inorganic and / or organic A polyolefin film containing fine powder is preferred.
The synthetic resin film is preferably a resin film containing a thermoplastic resin having a melting point of 180 to 300 ° C., specifically a resin film containing a polyester resin or poly (4-methylpent-1-ene). Preferably there is. The polyester resin is preferably polyethylene terephthalate.
The ultraviolet blocking layer preferably contains at least one ultraviolet absorber selected from the group consisting of benzotriazole, benzophenone, salicylate, cyanoacrylate, nickel and triazine, and is in the same layer composition. The content of the UV absorber is preferably 1 to 50% by weight.

The electrophotographic recording paper of the present invention can quickly release the charge, but in order to improve the recording quality such as density, color tone and gradation, the electrostatic capacity is 10 to 300 pF / cm ^2. It is preferable to adjust the range.
The electrophotographic recording paper of the present invention may be an adhesive label-shaped electrophotographic recording paper having an adhesive layer laminated on one side of the outermost layer, and further records a recording image including information such as a barcode, It is good also as the printed matter which printed and printed.

  When color recording is performed on the electrophotographic recording paper of the present invention by the electrophotographic recording method, an image having excellent recording quality such as density, color tone, gradation and the like can be obtained. In addition, the electrophotographic recording paper of the present invention exhibits excellent fixability, water resistance, and durability, and is excellent in practicality because it does not stick due to charging even when continuously printed.

  Hereinafter, the electrophotographic recording paper and recorded matter of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

《Electrophotographic recording paper》
[Features and layer structure]
The electrophotographic recording paper of the present invention is a sheet in which a toner-receiving layer containing a polymer antistatic agent is provided on at least one side of a water-resistant support, and has a surface-specific property at a temperature of 25 ° C. and a relative humidity of 20%. The resistance value is adjusted to 1 × 10 ^{7 to} 9 × 10 ¹² Ω. FIG. 1 and FIG. 2 show a preferred embodiment of the electrophotographic recording paper of the present invention having such characteristics. The electrophotographic recording paper 1 of the present invention shown in FIG. 1 is one in which a toner receiving layer 2 is provided on both surfaces of a water-resistant support 3. The electrophotographic recording paper 1 of the present invention shown in FIG. 2 has a toner receiving layer 2 provided on only one side of a water-resistant support 3. As shown in FIGS. 1 and 2, the support 3 can have a structure in which a synthetic resin film 5 is laminated on both surfaces of a paper material 4 via an adhesive layer 6.
The thickness of the electrophotographic recording paper of the present invention is usually 70 to 400 μm, preferably 85 to 350 μm, and more preferably 100 to 300 μm. Moreover, the basic weight is 70-400 g / m < ² > normally, Preferably it is 85-350 g / m < ² >, More preferably, it is 100-300 g / m < ² >.
Hereinafter, each layer and support constituting the electrophotographic recording paper of the present invention will be described, and physical properties of the electrophotographic recording paper will be mentioned.

[Toner receiving layer]
(Features and functions)
The toner-receiving layer used in the electrophotographic recording paper of the present invention contains a polymer antistatic agent so that the surface resistivity at a temperature of 25 ° C. and a relative humidity of 20% is in the range of 1 × 10 ^{7 to} 9 × 10 ¹² Ω. To do.
The toner receiving layer used in the electrophotographic recording paper of the present invention is an outermost layer of the electrophotographic recording paper, and is a layer that receives and fixes toner during electrophotographic recording (copying or laser printing), and is particularly water-resistant. In addition, an electrophotographic recording paper that is excellent in durability and that prevents post-printing charging and does not stick to each other is realized.

(Conventional antistatic agent)
Conventionally, monomeric antistatic agents represented by stearic acid monoglyceride, alkyldiethanolamine, sorbitan monolaurate, alkylbenzene sulfonate, alkyl diphenyl ether sulfonate, etc. are generally used as antistatic agents. Has a problem that water resistance is remarkably lowered when it is used in such an amount that it can exhibit antistatic performance due to its high water solubility and its weak cohesion.
Conductive inorganic fillers typified by ITO (indium doped tin oxide), ATO (antimony doped tin oxide), graphite whiskers, and the like can also provide an antistatic effect because the fillers do not come into contact with each other when added in a small amount. Absent. In addition, if the amount of the filler is in contact with each other, the amount of the binder is remarkably lowered, so that the water resistance is lowered and it is difficult to achieve both the water resistance and the antistatic effect.

On the other hand, since the polymer antistatic agent itself has a cohesive force, it is possible to form a coating layer having excellent water resistance.
Among the polymer antistatic agents, there are so-called electron conductive polymers that exhibit conductivity by π electrons in the molecular chain, such as polythiophene, polypyroyl, polyaniline, etc., but these electron conductive polymers are colored by conjugated systems. Generally, black, green, or blue-gray coloration is available, and if this is used, an excellent antistatic effect can be obtained, but it becomes a dull color electrophotographic recording paper and the image is not sharp. End up. Furthermore, these electronically conductive polymers are characterized by high electrical conductivity, and have a characteristic that the charge of the toner is released because the performance of diffusing the charge is too high. Since it is difficult to achieve a sufficient electrostatic capacity as an electrophotographic recording sheet, troubles in which the image density is not stable are likely to occur.

(Polymer antistatic agent used in the present invention)
The polymer antistatic agent used in the present invention must have both antistatic performance and water resistance performance, and has little influence on the antistatic effect even after a heating process by an electrophotographic toner fixing device. It is necessary. That is, the polymer antistatic agent used in the present invention is a fat-soluble polymer capable of setting the surface resistivity of the toner receiving layer at a temperature of 25 ° C. and a relative humidity of 20% within the range of 1 × 10 ^{7 to} 9 × 10 ¹² Ω. Antistatic agent. If it is fat-soluble, it can be used in combination with a binder resin having higher water resistance. In the present invention, the fat-soluble means that it dissolves in an organic solvent to be described later at a solid concentration of 5% by weight or more under normal temperature and pressure and does not generate a precipitate. The polymer antistatic agent used in the present invention is preferably a copolymer of a monomer exhibiting antistatic performance and a hydrophobic (lipophilic) monomer. By copolymerizing a hydrophobic monomer, the solubility in various organic solvents can be enhanced. Examples of such hydrophobic monomers include esters of acrylic acid or methacrylic acid with various alcohols.

  The polymer antistatic agent used in the present invention has an alkylene oxide group and / or a hydroxyl group in the molecule, and has a relatively small ion diameter such as lithium ion, sodium ion or potassium ion as a counter ion of the hydroxyl group. An ion conductive antistatic agent having alkali metal ions is more preferable. For example, an antistatic agent having a copolymer structure represented by the following general formula (1) contributes to water resistance and a unit having an alkylene oxide group that exhibits antistatic performance (improves lipophilicity). Since it has a structure composed of units having a lipophilic group, it is possible to obtain an antistatic agent with excellent water resistance, which is a preferred form. The specific gravity and degree of polymerization of each unit can be determined from the antistatic performance and water resistance performance to be obtained.

In the general formula (1), R ¹ and R ² each independently represents a hydrogen atom or a methyl group. When m is 2 or more, m R ^{1 s} may be the same or different. When n is 2 or more, n R ^{2 s} may be the same or different. Therefore, for example, R ¹ and R ² can all be methyl groups.
In the general formula (1), R ⁴ represents an alkyl group having 1 to 30 carbon atoms. The number of carbon atoms of the alkyl group may be selected from the range of, for example, 1 to 25, further 2 to 23, further 3 to 20, and further 4 to 18. Specific examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, dodecyl group, tridecyl group, stearyl group and the like. These may be linear or branched. When m is 2 or more, m R ^{4 s} may be the same or different. For example, an alkyl group having less than 10 carbon atoms and an alkyl group having 10 or more carbon atoms may be mixed, and further, an alkyl group having 1 to 6 carbon atoms and an alkyl group having 15 to 20 carbon atoms may be mixed. Also good.

In the general formula (1), A is one type of linking group selected from the following <Group 1> or one or more types of linking groups selected from the following <Group 1> and <Group 2> below. It represents a linking group in which one or more selected linking groups are alternately bonded, or a single bond.
<Group 1> An alkylene group having 1 to 6 carbon atoms which may have a substituent,
An arylene group having 6 to 20 carbon atoms which may have a substituent,
<Group 2> —CONH—, —NHCO—, —OCONH—, —NHCOO—,
-NH-, -COO-, -OCO-, -O-,
Examples of the C1-C6 alkylene group of <Group 1> include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and a hexylene group, and these may be linear or branched. Although it may be, it is preferably linear. Examples of the substituent include a hydroxyl group and an aryl group. Examples of the arylene group having 6 to 20 carbon atoms include a phenylene group, a naphthylene group, and an anthrylene group. Examples of the substituent include a hydroxyl group and an alkyl group. Examples of the arylene group substituted with an alkyl group include a tolylene group and a xylylene group. Moreover, as a coupling group selected from <Group 2>, a urethane group or an ester group can be preferably selected. As the linking group in which one or more linking groups selected from <Group 1> and one or more linking groups selected from <Group 2> are alternately bonded, “(the linking group selected from Group 1” is used. )-(Linking group selected from group 2) "or" (linking group selected from group 1)-(linking group selected from group 2)-(selected from group 1) Linking group)-(linking group selected from Group 2) "and the like. In the latter case, the two types (the linking group selected from the first group) may be the same as or different from each other, and the two types (the linking group selected from the second group) are the same as each other. It may or may not be.

In the general formula (1), R ³ represents a hydrogen atom, a chlorine atom or a methyl group, preferably a hydrogen atom or a methyl group. When p is 2 or more, p R ^{3 s} may be the same or different, but it is preferred that they are the same. Although p represents the integer of 1-100, 2-50 are preferable and 3-50 are more preferable. For example, when R ³ is a hydrogen atom, p is selected from the range of 10 to 35, more preferably 15 to 30, and further 20 to 25, or when R ³ is a methyl group, p is 1 to 20, May be selected from the range of 3 to 16, or 5 to 14.

In the general formula (1), when n is 2 or more, all of A, R ³ and p of n side chains bonded to n repeating units may be the same or different. Also good. For example, all of R ³ may be a hydrogen atom or a methyl group, or a hydrogen atom and a methyl group may be mixed. If hydrogen atom and methyl group are mixed, it is preferable that all the p number of R ³ constituting one of the side chains is either hydrogen atom or a methyl group.

In the general formula (1), M is an alkali metal, and can include Li, Na, K, and the like, and Li having a small ionic radius is preferably used from the viewpoint of conductivity. When n is 2 or more, n Ms may be the same or different. Preferred is the same case.
In general formula (1), m represents an integer of 0 to 300, n represents an integer of 1 to 300, and p represents an integer of 1 to 100. Preferably, m represents an integer of 0 to 200, n represents an integer of 10 to 200, and p represents an integer of 3 to 50.
The m repeating units and the n repeating units may be bonded so as to be a block copolymer, or may be bonded so as to be a random copolymer.

The production method of the antistatic agent having the structure represented by the general formula (1) is not particularly limited, and can be appropriately synthesized by combining known synthesis methods. Typically, it can be prepared by copolymerizing having R ¹ and R ⁴ (meth) acrylate monomers, and having R ² and alkylene oxide group-containing (meth) acrylate monomer. Specifically, it can be carried out by dissolving these monomers in an inert organic solvent and adding a polymerization initiator, followed by heating to 65 to 150 ° C. with stirring. The polymerization time is usually set to 1 to 24 hours.

Specific examples of the (meth) acrylate monomer having R ¹ and R ⁴ include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, cyclohexyl Examples thereof include alkyl (meth) acrylates such as (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, and stearyl (meth) acrylate.

The (meth) acrylate monomer having R ² and an alkylene oxide group can be produced by introducing an alkali metal into the alkylene oxide monomer. Examples of alkylene oxide monomers that can be suitably used in the present invention include, for example, (poly) ethylene glycol (meth) acrylate, (poly) propylene glycol (meth) acrylate, (poly) chloroethylene glycol (meth) acrylate, (poly And (poly) alkylene oxide (meth) acrylates such as tetramethylene glycol (meth) acrylate, methoxy (poly) ethylene glycol (meth) acrylate, and methoxy (poly) propylene glycol (meth) acrylate. Moreover, in these specific examples, the alkylene oxide monomer which has further connecting groups other than a single bond in the location corresponding to A of General formula (1) is also mentioned. For example, as a compound having a urethane bond in A, a compound described in JP-A No. 09-113704 can be used. The method for introducing an alkali metal corresponding to M is not particularly limited, but it is usually possible to impart ion conductivity by alkali metal ions by ionizing hydroxyl terminal by reacting an alkali metal salt with an alkylene oxide monomer. Examples of alkali metal salts that can be suitably used in the present invention include lithium, sodium or potassium perchlorates, or inorganic salts thereof such as chlorides, bromides, iodides, thiocyanides, and the like.

  The polymerization initiator used for copolymerization is preferably fat-soluble, and examples of suitable polymerization initiators include organic peroxides and azonitriles. Organic peroxides include alkyl peroxides (dialkyl peroxides), aryl peroxides (diaryl peroxides), acyl peroxides (diacyl peroxides), aroyl peroxides (diaroyl peroxides), ketone peroxides, peroxides Carbonates (peroxydicarbonates), peroxycarboxylates, hydroperoxides, peroxyketals, peroxyesters and the like are included. Examples of the alkyl peroxide include diisopropyl peroxide, ditertiary butyl peroxide, and tertiary butyl hydroperoxide. Examples of the aryl peroxide include dicumyl peroxide and cumyl hydroperoxide. Examples of the acyl peroxide include dilauroyl peroxide. Examples of aroyl peroxide include dibenzoyl peroxide. Examples of the ketone peroxide include methyl ethyl ketone peroxide and cyclohexanone peroxide. Examples of the azonitrile include azobisisobutylnitrile and azobisisopropionitrile.

  The molecular weight of the polymer antistatic agent used in the present invention is preferably in the range of 10,000 to 1,000,000 as the weight average molecular weight measured by gel permeation chromatography (GPC). If the molecular weight is 10,000 or more, the antistatic agent is difficult to ooze out from the formed toner receiving layer, so that sufficient water resistance tends to be easily obtained. If the molecular weight is 1,000,000 or less, since it is easy to mix with the binder component, coating defects are less likely to occur, and a uniform antistatic effect tends to be obtained.

  In the toner receiving layer of the present invention, the alkali metal ion concentration is preferably 0.01 to 1% by weight, more preferably 0.01 to 0.7% by weight, still more preferably 0.01 to 0.5% by weight. Thus, it is desirable to add a polymer antistatic agent. If the alkali metal ion concentration is 0.01% by weight or more, an antistatic effect is easily obtained, and sticking between discharged papers tends to be prevented when continuously printed by an electrophotographic printer. On the other hand, if the amount is 1% by weight or less, there is no excessive increase in hydrophilicity due to an increase in metal ions, so that the water-resistant adhesion of the toner tends to be easily maintained. These alkali metal ion concentrations are expressed as values to be set at the time of preparation, but can also be obtained by analysis using a technique such as ICP emission spectroscopic analysis after dry ashing.

  The amount of the polymer antistatic agent added to the toner receiving layer is appropriately determined depending on the amount of alkali metal ions contained, but is preferably 1 to 50% by weight, more preferably 2 to 45% by weight, and still more preferably 3 It is in the range of ˜40% by weight. If it is 1% by weight or more, it tends to be uniformly dispersed in the toner receiving layer, and a sufficient polymer antistatic effect tends to be obtained. On the other hand, if the amount is 50% by weight or less, there is a tendency that poor fixing of the toner hardly occurs because the balance with the amount of the binder resin and pigment particles added is good.

(Binder resin)
The toner-receiving layer of the present invention preferably contains a binder resin in order to impart toner fixability and stronger water resistance.
The binder resin used in the present invention is preferably a water-insoluble binder. By using a water-insoluble binder, a toner receiving layer having excellent water resistance can be obtained. Examples of water-insoluble binders include urethane resins, terpene resins, petroleum resins, ethylene-vinyl acetate copolymer resins, vinyl chloride resins, vinyl chloride-vinyl acetate copolymer resins, vinylidene chloride resins, vinyl chloride-vinylidene chloride copolymers. Copolymer resin, acrylate copolymer resin, methacrylate ester copolymer resin, chlorinated ethylene resin, chlorinated propylene resin, butyral resin, silicone resin, polyester resin, nitrocellulose resin, styrene-acrylic copolymer resin, styrene -Butadiene copolymer resin etc. can be mentioned. Any one of these binder resins may be used alone, or two or more kinds thereof may be mixed and used. Among these, urethane resins such as polyether urethane, polyester polyurethane, and acrylic urethane or acrylic ester copolymer resins have good compatibility (compatibility) with the above-described antistatic agent composed of an alkylene oxide compound, and are mixed. It is preferable because it is stable when applied as a paint, is easy to apply, and has good adhesion to the toner of the resulting toner receiving layer. The binder resin content in the toner receiving layer is preferably in the range of 10 to 99% by weight, more preferably 15 to 98% by weight, and still more preferably 20 to 97% by weight. If it is 10% by weight or more, the toner-receiving layer can have a sufficient cohesive force, so that there is a tendency that an image formed by the electrophotographic method is hardly peeled off. If it is 99% by weight or less, the antistatic effect tends to be easily obtained.

(Organic solvent)
The organic solvent that can be used in the present invention includes a general organic solvent, and is not particularly limited. The solubility parameter (hereinafter abbreviated as SP value) is preferably 6 to 12, more preferably 7 to 11. Here, the solubility parameter (SP value) is synonymous with a solubility parameter (Solubility Parameter), and is a characteristic value of a liquid that serves as a measure of the miscibility between liquids. When the SP value is δ, the molecular cohesive energy of the liquid is E, and the molecular volume is V, the SP value δ is expressed by δ = (E / V) ^1/2 .
Specific examples of the solvent having an SP value of 6 to 12 include n-hexane (SP value: 7.3), n-butanol (SP value: 11.4), 2-propanol (SP value: 11.5). , Toluene (SP value: 8.9), xylene (SP value: 8.8), methyl ethyl ketone (SP value: 9.3), acetone (SP value: 10), methyl isobutyl ketone (SP value: 8.4) , Cyclohexanone (SP value: 9.9), ethyl acetate (SP value: 9.1), isopropyl acetate (SP value: 8.4), butyl acetate (SP value: 8.5), tetrahydrofuran (SP value: 9) .5), ethyl cellosolve (SP value: 9.9), butyl cellosolve (SP value: 8.9), and the like. If the SP value is 12 or less, the solubility of the binder resin tends to be improved, and when a cross-linking agent is used, the cross-linking reaction is prevented from starting in the solution, and the stability of the paint tends to be improved. If the SP value is 6 or more, the volatility is not excessively high and the handling tends to be easy.

(Pigment particles)
The toner receiving layer of the present invention may contain pigment particles as necessary. The toner receiving layer may contain pigment particles in the range of 0 to 70% by weight. That is, it may or may not contain 70% by weight or less of pigment particles.
Pigment particles improve toner fixing properties due to their oil absorption, improve surface texture and gloss as extender pigments, improve whiteness as white pigments, improve anti-blocking performance by imparting surface irregularities, improve light resistance and weather resistance as UV reflectors , Etc. can be appropriately selected and used for the purpose of imparting performance. Organic and inorganic fine powders are used as pigment particles. Specific examples include silicon oxide, calcium carbonate, calcined clay, titanium oxide, zinc oxide, barium sulfate, diatomaceous earth, acrylic particles, styrene particles, polyethylene particles, polypropylene. Particles and the like. The particle diameter of the pigment particles is preferably 20 μm or less, more preferably 15 μm or less. If the particle diameter of the pigment particles is 20 μm or less, the pigment particles are unlikely to fall off from the formed coating layer, so that there is a tendency that the powder blowing phenomenon does not easily occur. The pigment particle content in the toner receiving layer is preferably in the range of 0 to 70% by weight, more preferably 0 to 60% by weight, and still more preferably 0 to 45% by weight. If the content of the pigment particles is 70% by weight or less, the toner receiving layer tends to have a sufficient cohesive force to easily suppress peeling of an image formed by the electrophotographic method.

(Coating)
The toner receiving layer of the present invention can be formed by forming a coating film on a support with a known coating apparatus and drying it. Specific examples of the coating apparatus include a die coater, a bar coater, a comma coater, a lip coater, a roll coater, a curtain coater, a gravure coater, a spray coater, a blade coater, a reverse coater, and an air knife coater.
The coating amount of the toner receiving layer is preferably 0.1 to 20 g / m ² , more preferably 0.5 to 8 g / m ² in terms of the solid content after drying. If the coating amount is 0.1 g / m ² or more, uniform antistatic performance tends to be easily obtained. If it is 20 g / m ² or less, the polymer antistatic agent is less likely to have a distribution in the thickness direction depending on the coating conditions and coating environment, so that stable antistatic performance and water resistance tend to be easily obtained.

[Support]
(Features and layer structure)
The electrophotographic recording paper of the present invention is characterized in that the above-described toner receiving layer is formed on at least one surface of a water-resistant support. The support imparts physical strength such as bending elasticity and tensile elasticity to the electrophotographic recording paper, whiteness and opacity as the recording paper, and further imparts water resistance and durability.
As the support, it is desirable to laminate a water-resistant synthetic resin film on at least one side of a water-resistant paper material. Lamination can be performed by a known method such as a dry lamination method or a melt lamination method. A more preferable laminating method is a dry laminating method in which an adhesive layer is provided between the support and the synthetic resin film and bonded together.
Further, as a preferred embodiment of the electrophotographic recording paper of the present invention, the supporting substrate may be one in which an ultraviolet blocking layer is laminated between a water-resistant paper material and a synthetic resin film. The ultraviolet blocking layer may also serve as an adhesive layer, or may be provided individually.

(Paper material)
The paper material that can be used for the electrophotographic recording paper of the present invention is preferably a water-resistant paper material having a water absorption in the range of 0 to 50 g / m ² according to the Cobb method based on JIS-P-8140: 1998. . Water absorbing degree is more preferably 0~40g / m ^2, and particularly preferably 0~30g / m ^2.
Specifically, a paper base paper that is coated or impregnated with a coating agent that imparts water resistance to pulp base paper, or a base paper that is coated or fused with a water-resistant synthetic resin. Processed paper such as photographic paper base paper, resin-impregnated paper, resin-coated paper, sulfuric acid paper, pseudosulfuric paper, water-resistant paper, oil-resistant paper, and waterproof paper can be used. Or the olefin resin film and synthetic paper containing an inorganic and / or organic fine powder can be illustrated.
The wall thickness of the paper material based on JIS-P-8118: 1998 is preferably 20 to 300 μm, and more preferably 50 to 250 μm.

The olefin resin film contains inorganic and / or organic fine powder together with the olefin resin. As a composition of an olefin resin film, it is preferable to contain 35 to 99 weight% of olefinic resins, and 1 to 65 weight% of inorganic and / or organic fine powders. More preferably, it contains 50 to 95% by weight of olefin resin and 5 to 50% by weight of inorganic and / or organic fine powder.
Examples of the olefin resin contained in the olefin resin film include ethylene resins such as high density polyethylene and medium density polyethylene, propylene resin, poly (4-methylpent-1-ene), ethylene-cyclic olefin copolymer Olefin-based resins such as coalescence can be applied. Further, a mixture of two or more of these resins may be applied. Among these, high-density polyethylene and propylene-based resin are preferably applied from the viewpoints of cost, water resistance, and chemical resistance.

The propylene-based resin is a propylene homopolymer, mainly composed of polypropylene and propylene having isotactic, syndiotactic and various stereoregularities, and ethylene, butene-1, hexene-1, heptene- And a copolymer with an α-olefin such as 1,4-methylpentene-1. This copolymer may be a binary, ternary or quaternary system, and may be a random copolymer or a block copolymer.
Examples of the inorganic fine powder contained in the olefin-based resin film include, for example, calcium carbonate, calcined clay, silica, diatomaceous earth, talc, titanium oxide, barium sulfate, alumina, and the like, and the average particle size thereof is 0.01 to A thing of 15 micrometers can be applied. As the organic fine powder, one having a melting point or glass transition temperature higher than the melting point of the main component resin serving as a matrix of the olefin resin film and incompatible with the olefin resin can be applied. Specifically, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, nylon-6, nylon-6,6, homopolymer of cyclic olefin, copolymer of cyclic olefin and ethylene, etc., melting point 120 ° C. to 300 ° C. Or those having a glass transition temperature of 120 ° C to 280 ° C.

The structure of the olefin-based resin film includes a single layer structure, a two-layer structure of a base layer and a surface layer, a three-layer structure in which surface layers are laminated on both sides of the base layer, or another resin film layer between the base layer and the surface layer. Any multilayer structure may be used, and these multilayer structures can be produced by a known method such as a coextrusion method, a melt lamination method, or a dry lamination method.
When the olefin resin film has a multilayer structure having a base layer and a surface layer, the base layer contains 45 to 98% by weight of olefin resin and 2 to 55% by weight of inorganic and / or organic fine powder. preferable. The surface layer contains 25 to 100% by weight of the olefin resin and preferably contains 75% by weight or less of the inorganic and / or organic fine powder or not. In a more preferred form, the base layer contains 50 to 95% by weight of olefin resin, and contains 5 to 50% by weight of inorganic and / or organic fine powder, and the surface layer contains 30 to 99% by weight of olefin resin. It contains 1 to 70% by weight of inorganic and / or organic fine powder.

  The olefin-based resin film may further contain a heat stabilizer, a light stabilizer, a dispersant, a lubricant, and the like as necessary. For example, a stabilizer such as sterically hindered phenol, phosphorus and amine is used as a heat stabilizer in an amount of 0.001 to 1% by weight, and a stabilizer such as sterically hindered amine, benzotriazole and benzophenone is used as a light stabilizer. As a dispersant for 0.001 to 1% by weight of inorganic fine powder, a silane coupling agent, a higher fatty acid such as oleic acid or stearic acid, metal soap and the like may be added in an amount of 0.01 to 4% by weight.

The olefin resin film that can be used in the base material layer of the present invention is preferably a stretched film that is stretched and molded in at least a uniaxial direction in the molding process. Those having fine pores inside by stretching can improve the opacity of the recording paper and can improve the capacitance.
As a method for stretching the resin film, a conventionally known method can be applied. For example, longitudinal stretching using a difference in peripheral speed of a roll group, rolling using a plurality of rolls (longitudinal stretching), lateral stretching using a tenter, the longitudinal Sequential biaxial stretching combining stretching and transverse stretching, simultaneous biaxial stretching using a combination of a tenter and a linear motor, simultaneous biaxial stretching using a tubular method, simultaneous biaxial stretching using a pantograph type stretching machine, etc. it can. The temperature at the time of extending | stretching is suitably selected according to the kind of olefin resin to be used, and an extending | stretching process. Specifically, in the case of a propylene homopolymer (melting point 155 to 167 ° C.), 110 to 164 ° C., in the case of high density polyethylene (melting point 121 to 134 ° C.), 80 to 120 ° C., 2 to 60 from the melting point. It is preferable to set the temperature to a lower temperature. The stretching speed is preferably 20 to 350 m / min.

  A draw ratio is not specifically limited, It selects suitably by the objective and the characteristic of the olefin resin to be used. For example, when using a propylene homopolymer or a propylene-based copolymer and uniaxially stretching, it is preferably 1.2 to 12 times, more preferably 2 to 10 times, and when biaxially stretching, The area magnification is preferably 1.5 to 60 times, more preferably 10 to 50 times. When other olefinic resins are used and uniaxially stretched, the ratio is preferably 1.2 to 10 times, more preferably 2 to 5 times, and when biaxially stretched, the area ratio is preferably 1. 5 to 20 times, more preferably 4 to 12 times. After stretching, heat treatment (annealing treatment) is performed as necessary.

  An olefin resin film containing an inorganic and / or organic fine powder is stretched under the above conditions to form fine voids (holes) inside the film, resulting in an opacity (JIS P-8138). 85% or more, preferably 90% or more, and the porosity defined by the following formula (1) is 10 to 60%, preferably 15 to 45%, and suitable as a paper material for electrophotographic recording paper. Can do.

（ρ₀は樹脂フィルムの真密度を示し、ρは樹脂フィルムの密度を示す）
延伸フィルムの空孔率が１０％以上であれば、電子写真記録用紙の白色化、不透明化、軽量化の調整が容易になる傾向があり、逆に空孔率が６０％以下であれば、電子写真記録用紙の強度（引張強度、曲げ強度）が得られやすくなる傾向がある。

(Ρ ₀ indicates the true density of the resin film, and ρ indicates the density of the resin film)
If the porosity of the stretched film is 10% or more, whitening, opacification, and weight reduction of the electrophotographic recording paper tend to be easily adjusted, and conversely if the porosity is 60% or less, There is a tendency that the strength (tensile strength, bending strength) of the electrophotographic recording paper is easily obtained.

The thickness of the olefin resin film containing the inorganic and / or organic fine powder is preferably in the range of 20 to 300 μm, and more preferably 50 to 250 μm, as described above. If the thickness of the film is 20 μm or more, it tends to be easy to produce a stretched film having voids, and if it is 300 μm or less, it will be easy to supply to the market in the form of a wound roll when it is finally made an electrophotographic recording paper. Tend.
It is preferable to use an olefin resin film having a capacitance of 4 to 1000 pF / cm ² .

(Synthetic resin film)
As the synthetic resin film that can be used for the electrophotographic recording paper of the present invention, the electrophotographic recording paper has heat resistance, durability, suitable capacitance, etc. so that information recording by an electrophotographic recording method can be suitably performed. It characterizes.
This is preferably a synthetic resin film having water resistance in combination with the above paper material.

  As the synthetic resin film, a synthetic resin film having a water resistance and an insulating property with a thickness of usually 5 to 100 μm, preferably 12 to 50 μm is applied. Synthetic resins imparting water resistance and insulation include crystalline ethylene resins such as high density polyethylene, medium density polyethylene, and low density polyethylene, crystalline propylene resins, poly (4-methylpent-1-ene), ethylene -Crystalline olefin resins such as cyclic olefin copolymers; polyamide resins such as nylon-6, nylon-6,6, nylon-6,10, nylon-6,12; polyethylene terephthalate and other monomers and other components Copolymer, polyethylene naphthalate, polylactic acid, aliphatic polyester and other thermoplastic polyester resins; polycarbonate, atactic polystyrene, isotactic polystyrene, syndiotactic polystyrene, polyphenylene sulfide and other thermoplastic resins Is mentioned. These may be used in combination of two or more.

  Among these thermoplastic resins, from the viewpoint of imparting heat resistance suitable for an electrophotographic recording method, a resin having a melting point based on JIS-K-7121: 1987 in the range of 180 ° C. to 300 ° C. is used as a main component. preferable. Therefore, as the thermoplastic resin that can form the synthetic resin film of the present invention, polyamide resin (about 180 to 270 ° C.), poly (4-methylpent-1-ene) (about 230 ° C.), isotactic polystyrene (about 240 ° C.), polycarbonate (about 250 ° C.), polyester resin (about 260 ° C.), syndiotactic polystyrene (about 270 ° C.), polyphenylene sulfide (about 280 ° C.) and the like. If a resin having a melting point of 180 ° C. or higher is used as the main component of the synthetic resin film, the synthetic resin film is not easily deformed or melted by heat in the fixing process of the toner. It tends to be easy to prevent sticking to a fixing device (such as a heat-sealing roll) or damage to a recording device. If a resin having a melting point of 300 ° C. or less is used, it is easy to produce a film having a uniform thickness, so that uniform information recording tends to be facilitated. The main component of the present invention occupies 50% by weight to 100% by weight of the entire synthetic resin film. If it is 50% by weight or more, the desired performance of the synthetic resin film of the present invention tends to be exhibited. Examples of subcomponents include other thermoplastic resins and fillers.

Among these thermoplastic resins, it is particularly preferable to use a polyester resin as a main component. Examples of the polyester resin include bifunctional carboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, bis-α, β (2-chlorophenoxy) ethane-4,4′-dicarboxylic acid, adipic acid, and sebacic acid. And polyester obtained by polycondensation of at least one of the above and at least one glycol such as ethylene glycol, triethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, and the like. Furthermore, the polyester obtained by adding the polycarboxylic acid which can be polycondensed to said bifunctional carboxylic acid and glycol, and carrying out polycondensation can be mentioned.
Among these polyester-based resins, polyethylene terephthalate obtained from polycondensation of terephthalic acid and ethylene glycol is easy to obtain a film with a uniform thickness, is easy to process, and has an appropriate capacitance with no excess or deficiency Is particularly preferable in that it can be imparted.

  In the present invention, by using a support comprising the above-mentioned paper material having water resistance and a synthetic resin film having water resistance, the water resistance of electrophotographic recording paper can be greatly improved, and a more preferred embodiment. It can be.

(Adhesive layer)
When the support used for the electrophotographic recording paper of the present invention is formed from the above-mentioned paper material and synthetic resin film, it is preferable to use an adhesive layer for laminating them and to laminate them. For bonding, an adhesive such as a solvent-based adhesive or a hot-melt adhesive is provided as an adhesive layer on a paper material or a synthetic resin film by a technique such as coating, spraying, melt extrusion laminating, and the like. It can be performed by a usual method such as dry lamination or melt lamination using a heat-fusible film or a melt-extruded film.
Examples of the solvent-based adhesive include resin components composed of acrylic resins, urethane resins, ether resins, ester resins, epoxy resins, rubber resins, silicone resins, ABS resins, etc. Typical examples are liquid adhesives in the form of a solution type or an emulsion type, which can be dissolved, dispersed, emulsion-dispersed and diluted in the phase by using a liquid and can be applied.

These adhesives are applied by die coater, bar coater, comma coater, lip coater, roll coater, rod coater, curtain coater, gravure coater, spray coater, blade coater, reverse coater, air knife coater, slide hopper, etc. Is called. Thereafter, smoothing is performed as necessary, and an adhesive layer is formed through a drying step.
These adhesives are generally applied such that the basis weight is 0.5 to 25 g / m ^2, and an adhesive layer is provided.

When using an adhesive, apply the adhesive on the surface of the paper material, which is the base material layer, and then stack the synthetic resin film, which is a synthetic resin film, and apply pressure bonding with a pressure roll, or use a synthetic resin film. What is necessary is just to apply | coat this adhesive agent on the back surface of the synthetic resin film which is a resin film, and then piles the paper material which is a base material layer, and press-bonds it with a press roll.
Hot melt adhesives include polyolefin resins such as low density polyethylene, ethylene / vinyl acetate copolymers, metal salts of ethylene / (meth) acrylic acid copolymers (so-called Surlyn), chlorinated polyethylene, chlorinated polypropylene, etc. And polyamide resins, polybutyral resins, urethane resins and the like.
When using a hot-melt adhesive, apply by beating, curtain coating, slot coating, etc. on the surface of the paper material that is the base material layer, or use the paper material that is the base material layer. What is necessary is just to laminate | stack by extruding in the shape of a molten film from the die | dye on the surface, and then stacking | stacking the synthetic resin film which is a synthetic resin film, and pressurizing-bonding with a press roll.

  Moreover, you may contain the ultraviolet absorber which absorbs any one wavelength of 280-400 nm as these details mention later. By containing the ultraviolet absorber, it is possible to form an adhesive layer that also serves as an ultraviolet blocking layer.

(UV blocking layer)
The electrophotographic recording paper of the present invention can be provided with an ultraviolet blocking layer. The UV blocking layer is preferably provided between the paper material and the synthetic resin film. The ultraviolet blocking layer is a layer containing an ultraviolet absorber, or a layer containing an ultraviolet absorber and an ultraviolet reflector. By providing an ultraviolet blocking layer on the electrophotographic recording paper of the present invention, discoloration (yellowing) of the internal paper material can be effectively suppressed, and long-term use outdoors can be enabled.

  When an ultraviolet blocking layer is provided outside the support (for example, provided on the toner receiving layer or between the toner receiving layer / synthetic resin film), water resistance, solvent resistance, and ink adhesion are preferably reduced. Absent. Further, when the synthetic resin film itself is used as an ultraviolet blocking layer (for example, when an ultraviolet absorber or the like is kneaded and mixed in the synthetic resin film), the moldability of the synthetic resin film is lowered and the uniformity of the film thickness is impaired. The intended purpose cannot be achieved. Therefore, when the ultraviolet blocking layer is provided, the desired effect can be achieved by providing it as a separate layer, preferably between the paper material and the synthetic resin film.

The ultraviolet absorber that can be used for the ultraviolet blocking layer is one that absorbs light having a wavelength of any one of 280 to 400 nm. For example, any of benzotriazole, benzophenone, salicylate, cyanoacrylate, nickel, and triazine, or a mixture thereof can be used, either low molecular weight type or high molecular weight type.
Specific examples of the benzotriazole ultraviolet absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-). Butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amylphenyl) benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5′-) Methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(1-methyl-1-phenylethyl) -5′-1,1,3,3 tetramethylbutylphenyl) Examples include benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5 ′-(2-octyloxycarbonyl) ethylphenyl) benzotriazole. Specific examples of the benzophenone ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyl. Examples thereof include oxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2,2′-dihydroxy-4,4′dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone. Specific examples of salicylate-based UV absorbers include phenyl salicylate, 4-t-butylphenyl salicylate, 2,4-di-t-butylphenyl-3 ′, 5′-di-t-butyl-4′- Examples thereof include hydroxybenzoate. Specific examples of the cyanoacrylate ultraviolet absorber include ethyl (β, β-diphenyl) cyanoacrylate, 2-ethylhexyl (β, β-diphenyl) cyanoacrylate, and the like. Specific examples of nickel-based ultraviolet absorbers include [2,2-thiobis (4-t-octylphenolate)]-n-octylamine nickel salt, [2,2-thiobis (4-t-octylphenol). Lat)]-2-ethylhexylamine nickel salt, nickel dibutyldithiocarbamate and the like. Specific examples of the triazine-based ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol. Among these, benzotriazole-based ultraviolet absorbers are preferable, and 2- (2′-hydroxy-3 ′-(1-methyl-1-phenylethyl) -5′-1,1,3,3-tetramethylbutylphenyl is preferable. ) Benzotriazole (CAS No. 739369-11-1), 2- (2′-hydroxy-3′-t-butyl-5 ′-(2-octyloxycarbonyl) ethylphenyl) benzotriazole (CAS No. 127519-) 17-9) is preferred.

The ultraviolet reflector that can be used in the ultraviolet blocking layer is one that reflects and / or scatters light of any wavelength of 280 to 400 nm. For example, any one of zinc oxide, titanium oxide, cerium oxide, tungsten oxide, strontium titanate, or a mixture thereof.
The ultraviolet absorber and the ultraviolet reflector may be used alone or in combination.
The ultraviolet blocking layer desirably contains at least one type of ultraviolet absorber. When the ultraviolet blocking layer is formed from an ultraviolet reflector containing no ultraviolet absorber, discoloration of the electrophotographic recording paper itself is reduced when the printed matter of the electrophotographic recording paper of the present invention is used outdoors. The amount of ultraviolet rays applied to the toner and coating layer above increases, and the toner is likely to be discolored and deteriorated, resulting in a decrease in the sharpness of the recorded image and a decrease in the adhesion of the image.

The content of the ultraviolet absorber in the ultraviolet blocking layer is preferably in the range of 1 to 50% by weight, more preferably 2 to 40% by weight, still more preferably 5 to 30% by weight. If the amount of the ultraviolet absorber is 1% by weight or more, a clear recorded image tends to be easily obtained due to the discoloration suppressing effect of the electrophotographic paper itself. If it is 50% by weight or less, the water resistance and solvent resistance of the ultraviolet blocking layer tend to be easily obtained.
The ultraviolet blocking layer may be a single layer or a multilayer structure of two or more layers. Further, an ultraviolet absorber may be added to the adhesive layer for adhering the paper material and the synthetic resin film to be used as the ultraviolet absorbing layer.
If an ultraviolet absorber is added to the adhesive layer to serve as the ultraviolet absorbing layer, the above-mentioned amount of the above-mentioned ultraviolet light inhibitor may be used in combination with the above-mentioned adhesive layer component.

  As a method for forming the ultraviolet blocking layer separately from the adhesive layer, co-extrusion with paper material and / or synthetic resin film, melt lamination to paper material and / or synthetic resin film, paper material and / or synthetic resin Examples include coating on a film. Among these, a method in which a coating material obtained by mixing the above-described ultraviolet absorber and / or ultraviolet reflector with a known binder component is prepared and applied to a paper material or a synthetic resin film to provide a coating film is preferable. Specific examples of known binder components include oxidized starch, etherified starch, methoxycellulose, carboxymethylcellulose, hydroxyethylcellulose, casein, gelatin, soy protein, polyvinylhydrin, polyacrylamide, vinyl alcohol, polyacrylic acid, and ester. Urethane resin, ether urethane resin, acrylic urethane resin, terpene resin, petroleum resin, ethylene-vinyl acetate copolymer resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinylidene chloride resin, vinyl chloride-vinylidene chloride copolymer resin , Acrylic acid ester copolymer resin, methacrylic acid ester copolymer resin, butyral resin, silicone resin, polyester resin, nitrocellulose resin, styrene-acrylic copolymer resin, styrene-butyl resin Diene copolymer resin. Among them, polyacrylic acid, ester urethane resin, ether urethane resin, acrylic urethane resin, ethylene-vinyl acetate copolymer resin, acrylic ester copolymer resin, methacrylic ester copolymer resin, styrene-acrylic copolymer resin, styrene- A butadiene copolymer resin is preferred.

The thickness of the ultraviolet blocking layer is preferably in the range of 0.1 to 30 μm, more preferably 0.3 to 25 μm, and still more preferably 0.5 to 20 μm. If the thickness is 0.1 μm or more, discoloration of the electrophotographic paper itself tends to be prevented, and deterioration of the recorded image sharpness tends to be easily prevented. If it is 30 μm or less, it is easy to produce an electrophotographic recording paper having a uniform thickness, so that a uniform recorded image tends to be easily obtained.
Therefore, the layer structure of the support including the ultraviolet blocking layer is as follows: synthetic resin film / ultraviolet blocking layer (also serving as an adhesive layer) / paper material, synthetic resin film / ultraviolet blocking layer / adhesive layer / paper material, synthetic material It may take a form including resin film / adhesive layer / ultraviolet ray blocking layer / paper material, synthetic resin film / adhesive layer / ultraviolet ray blocking layer / adhesive layer / paper material.
The ultraviolet blocking layer that can be used in the electrophotographic recording paper of the present invention is preferably colorless and transparent or white for the purpose of use.

[Protective layer]
As one aspect of the electrophotographic recording paper of the present invention, a synthetic resin film is laminated on one surface (front surface) of a paper material, and a toner receiving layer is further provided on the synthetic resin film, and the other surface (back surface) of the paper material. It is also possible to provide a protective layer made of a synthetic resin film.
As a synthetic resin film used for the protective layer, a synthetic resin film having a water resistance and an insulation property of a thickness of usually 5 to 100 μm, preferably 12 to 50 μm is applied. The kind of the synthetic resin used for the protective layer is not particularly limited. For example, ethylene resins such as high density polyethylene and medium density polyethylene, propylene resins such as polypropylene, homopolymers of α-olefins having 2 to 8 carbon atoms such as poly (4-methylpent-1-ene), ethylene- Olefin resins such as α-olefin 2-5 types of copolymers such as cyclic olefin copolymers; polyamide resins such as nylon-6, nylon-6,6, nylon-6,10, nylon-6,12 ; Polyethylene terephthalate and copolymers obtained by copolymerizing other components with the same monomer; thermoplastic polyester resins such as polyethylene naphthalate, polylactic acid and aliphatic polyester; polycarbonate; atactic polystyrene, isotactic polystyrene, syndiotactic Polystyrene resins such as polystyrene; polyphenylene The thing substantially equivalent to the synthetic resin film of synthetic resin films, such as sulfide, can be used. Furthermore, you may mix and use those 2 or more types.

  In the case of using the adhesive to constitute the electrophotographic recording paper, the adhesive is applied to both sides of the paper material, which is a paper material, and then the synthetic resin film, which is a synthetic resin film, is applied to the front surface. A synthetic resin film that is a protective layer is overlaid and pressure-bonded with a pressure roll, or an adhesive is applied to the back surface of the synthetic resin film that is a protective layer, and then a paper material that is a paper material is overlaid. What is necessary is just to press-bond with a pressure roll. When the hot melt adhesive is used, it is laminated on the surface and back surface of the paper material, which is a paper material, by extruding it from a die in the form of a molten film. A certain synthetic resin film may be superposed and pressure bonded with a pressure roll.

[Adhesive layer]
The electrophotographic recording paper of the present invention may have an adhesive layer formed on one side of the outermost layer. The type and thickness (coating amount) of the pressure-sensitive adhesive layer can be variously selected depending on the type of adherend, the environment in which it is used, the strength of adhesion, and the like. The pressure-sensitive adhesive layer can be formed by coating and drying a commonly used solvent-based or water-based pressure-sensitive adhesive. As the adhesive, synthetic polymer adhesives such as natural rubber, synthetic rubber, and acrylic can be used. In the form of a solution dissolved in an organic solvent, a dispersion dispersed in an aqueous solvent, an emulsion, etc. Can be used. Further, in order to improve the opacity of the electrophotographic recording paper, the pressure sensitive adhesive may contain a pigment such as titanium white. The pressure-sensitive adhesive layer can be formed by coating it on the silicone-treated surface of release paper or process paper in a solution state, which can be transferred onto the electrophotographic recording paper, or directly on the electrophotographic recording paper. It can also be formed by coating. The adhesive is applied by a die coater, bar coater, roll coater, lip coater, gravure coater, spray coater, blade coater, reverse coater, air knife coater or the like. Further, smoothing is performed as necessary, and a pressure-sensitive adhesive layer is formed through a drying step. Although the thickness of an adhesive layer can be variously selected according to the intended purpose of a label, it is 2-30 micrometers normally, Preferably it is 5-20 micrometers.

[Release paper]
The electrophotographic recording paper of the present invention may further have a release paper on the surface of the pressure-sensitive adhesive layer. There is no problem if a release paper is provided at the time of electrophotographic recording, and the release paper is removed for use on an adherend. As the release paper, generally common paper can be used. For example, high-quality paper or kraft paper can be used as it is or by calendering, resin coating or film lamination, glassine paper, coated paper, plastic film or the like subjected to silicone treatment. When the release paper is applied to an electrophotographic recording paper, in order to improve the peelability from the pressure-sensitive adhesive layer, it is common to use a release paper that has been subjected to silicone treatment on the surface that contacts the pressure-sensitive adhesive layer.

[Physical properties of electrophotographic recording paper]
(Surface specific resistance)
The surface resistivity of the electrophotographic recording paper of the present invention is a value measured by the following method. That is, the electrophotographic recording paper of the present invention is cut out to a size of 10 cm square, and this is conditioned for 2 hours or more in an atmosphere of a temperature of 25 ° C. and a relative humidity of 20% to obtain a measurement sample. Thereafter, the surface of the toner-receiving layer of the measurement sample in the same environment was measured with an insulation meter (manufactured by Toa Denpa Kogyo Co., Ltd., model number: DSM-8103) using the electrode described in JIS-K-6911. Measure the resistance value (Ω).
The surface specific resistance value measured on the toner receiving layer side of the electrophotographic recording paper of the present invention is in the range of 1 × 10 ^{7 to} 9 × 10 ¹² Ω in an environment of humidity 25 ° C. and relative humidity 20%, It is preferably in the range of 1 × 10 ^{8 to} 9 × 10 ¹² Ω. If the surface specific resistance value is less than 1 × 10 ⁷ , abnormal transfer of toner may occur or the transferred toner may flow when the recording paper touches the ground in the electrophotographic recording apparatus. For example, a clear image may not be obtained. If it exceeds 9 × 10 ¹² Ω, the antistatic effect is insufficient, and sticking occurs between the recording sheets discharged after printing. In the present invention, in order to grasp the antistatic performance immediately after discharge in the electrophotographic recording apparatus, the surface resistivity is measured in a severe environment under extremely low humidity. Even when measured in an atmosphere at a temperature of 23 ° C. and a relative humidity of 50%, which is used to measure the value, it is desirable to be within this range.

(Capacitance)
Electrophotographic recording sheet of the present invention preferably has a capacitance per unit electrode area is 10~300pF / cm ^2, more preferably 12~250pF / cm ^2, at 15~200pF / cm ² More preferably it is. If the electrostatic capacity of the electrophotographic recording paper is 10 pF / cm ² or more, the toner transfer rate tends to be increased and a practical print density tends to be easily obtained. If the capacitance of the electrophotographic recording paper is 300 pF / cm ² or less, a clear and gradation recorded image tends to be easily obtained. That is, if the electrostatic capacity is 300 pF / cm ² or more, the toner charge is not stabilized and the toner is scattered before being heat-fixed by a heat roll, and a clear image cannot be obtained. However, there is a tendency that the paper becomes dirty due to the reattachment of the scattered toner, or a problem that an excessive toner is transferred and an image having no gradation is generated.
If the electrostatic capacity of the electrophotographic recording paper is within a preferable range, the recording paper can be sufficiently charged to hold an electrostatic charge, and the toner adhering to the photosensitive drum after exposure can be transferred and adhered efficiently. Therefore, it is easy to obtain good recording quality such as density, color tone, gradation, etc. of the printed matter and toner fixing property.

  The electrostatic capacity includes a parallel equivalent capacity or a series equivalent capacity. In general, the measurement method for the equivalent capacitance is selected according to the measurement frequency range. When the measurement frequency is 10 Hz or less, an ultra-low frequency bridge is used. When the measurement frequency is 10 Hz to 3 MHz, a transformer bridge is used. When the measurement frequency exceeds 1 MHz, a parallel T-type bridge, a high-frequency shelling bridge, a Q meter, and a resonance method are used. The standing wave method and the cavity resonance method are used. In addition, it is possible to measure the voltage / current vector with respect to the circuit component with respect to the AC signal at the measurement frequency, and measure the capacitance using this value.

As a measuring device for measuring the capacitance of recording paper, a sample is sandwiched between a flat plate-like electrode and a flat guard electrode arranged in parallel at a constant pressure, and a voltage of about 5 V can be applied, and the measurement frequency is A measuring device that can be arbitrarily selected is preferred. According to such a measuring machine, by changing the frequency, the frequency dependence of the sample can be grasped, and it can be used as an index of the appropriate usage range. The sample is preferably as uniform as possible and has a smooth surface. If the surface condition is poor, a gap (air layer) is formed between the sample and the electrode, giving a large error to the measured value. In this case, in order to complete electrical contact between the sample and the electrode, it is preferable to apply a silver conductive paint or perform vacuum deposition. Specific examples of the measuring device include Agilent Technologies' “4192A LF IMPEDANCE ANALYZER”, Yokogawa Electric's “LCR Meter 4274A”, Hioki Electric's “HIOKI 3522 LCR High Tester”, and the like. It is done.
For the measurement of the electrostatic capacity of the electrophotographic recording paper of the present invention, “4192A LF IMPEDANCE ANALYZER” manufactured by Agilent Technologies was used. Under the environmental conditions of a temperature of 23 ° C. and a relative humidity of 50%, A sample larger than the electrode diameter was sandwiched between a counter electrode having a diameter of 56 mm, a voltage of 5 V was applied, measurement was performed at a frequency in the range of 10 Hz to 1 MHz, and a measurement value at a frequency of 300 Hz was used as a representative value.

<Recording on electrophotographic recording paper>
[Recording device]
The electrophotographic recording paper of the present invention can be favorably color-recorded by an electrophotographic recording apparatus such as a copying machine or a laser printer. In the electrophotographic color recording method, (1) an intermediate transfer method in which an intermediate transfer is performed for each color, a plurality of colors are transferred to an intermediate transfer member, and then transferred and developed on a sheet. (2) two or more photosensitive members are used, A tandem method that transfers and develops multiple colors on paper one by one, and (3) a tandem + transfer method that uses two or more photoconductors, transfers multiple colors one by one to an intermediate transfer body, and then transfers and develops them on paper. There are three types. In the present invention, in particular, (2) and (3) are collectively referred to as a tandem system. The electrophotographic recording paper of the present invention can be used for the intermediate transfer system of (1), but is preferably used for the tandem system of (2) and (3). In the method (1), in the case of a small-sized electrophotographic copying machine or the like, the electrophotographic recording paper may be squeezed while being transported in the apparatus and may be difficult to use. The tandem methods (2) and (3) are compatible with high-speed operation, and are preferable because the electrophotographic recording paper is hardly squeezed during conveyance because of the structure of the apparatus.

  The electrophotographic recording paper of the present invention may be subjected to ordinary printing such as oil-based offset printing, UV offset printing, gravure printing, flexographic printing, etc. before recording using the recording apparatus. If necessary, a management bar code may be printed by such printing, thermal transfer method, or electrophotographic method. The electrophotographic recording paper of the present invention is subjected to full surface printing or partial printing on the back surface (the surface opposite to the toner receiving layer) of the synthetic resin film before lamination with the base material layer in order to enhance sales promotion and visibility. You may give it. Similarly, full surface printing or partial printing may be performed on the surface of the paper material on which the synthetic resin film is laminated before the synthetic resin film is laminated. These printings are preferably performed so as to be regular information when viewed through a synthetic resin film.

[Recordings]
The recorded material using the electrophotographic recording paper of the present invention includes POP cards (posters, stickers, displays, etc.), store information (pamphlets, company information, product writing, menus, etc.), underlays (lunch mats, table mats, stationery supplies) Etc.), manuals (various manuals for duties, operations, operations, etc., process charts, timetables, etc.), charts (nautical charts, weather charts, charts, ruled line charts, etc.), catalogs, cards (price cards, point cards, members cards, Various membership cards, student IDs, licenses, employee IDs, entrance / exit certificates, association IDs, ID cards, student attendance cards, book cards, examination cards, management cards, parking licenses, ski tickets, CDs, MD title cards , CD, MD index card, photo card, etc.), panel, plate (alternative to metal plate), bromide, preservation document Word processor documents, various lists, appraisals, certificates, important documents, certificates, etc.), picture books, drawings (architecture drawings, civil engineering site screens, etc.), maps (nautical charts, route maps, outdoor maps, etc.), commuter pass, store prices Table, mountain climbing guide, business card, lost child tag, cooking recipe, information board (sales guidance, direction / destination guidance, sweets / food, etc.), gardening POP (hanging label, feed label, etc.), schedule table, road Signs (funerals / housing exhibition places, etc.), circular boards, room name tags, school records, display boards (forbidden to enter, forest road work, etc.), stakes, nameplates, calendars (with images), simple whiteboards, postcards, greetings Cards, flyers, picture books, picture-story shows, portable timetables, album picture diaries, paperwork (paper craft), copy manuscripts, round fans, megaphones, mouse pads, bookmarks, pet toilets, packaging materials ( Paper, boxes, bags, etc.), coasters, flower pots, non-laminate prints, label lighter replacement prints, adhesive labels, tags (air tags, IC tags, triage tags), etc. It is. In particular, it can be suitably used for applications based on outdoor use.

  Hereinafter, the present invention will be described more specifically with reference to Preparation Examples, Production Examples, Examples and Comparative Examples. In addition, the material, usage-amount, ratio, processing content, and processing procedure shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Binder Resin Preparation Example 1]
2-hydroxyethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd., reagent) 15 parts by weight, methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd., reagent) 50 parts by weight, ethyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) , Reagent) and 100 parts by weight of toluene were charged into a three-necked flask equipped with a stirrer, a reflux condenser and a thermometer, and after nitrogen substitution, 2,2′-azobisisobutyronitrile (Wako Pure Chemical Industries, Ltd.) 0.6 parts by weight of Kogyo Co., Ltd., reagent) was added as an initiator, and polymerization was carried out at 80 ° C. for 4 hours. The resulting solution was a 50 wt% toluene solution of a hydroxyl group-containing (meth) acrylic acid ester copolymer resin having a hydroxyl value of 65. Next, 40 parts by weight of 20% by weight methyl ethyl ketone solution of vinyl chloride-vinyl acetate copolymer (manufactured by Shin-Daiichi PVC Co., Ltd., trade name: ZEST C150ML) and hexamethylene diisocyanate (Nippon Polyurethane Industry) were added to 100 parts by weight of this solution. 20 parts by weight of 75% by weight ethyl acetate solution (trade name: Coronate HL, manufactured by Co., Ltd.) was added, and a solvent in which toluene and methyl ethyl ketone were mixed 1: 1 was added to this mixture to adjust the solid content to 20% by weight. Thus, a binder resin solution was obtained.

[Binder Resin Preparation Example 2]
Poly [(3-methyl-1,5-pentanediol) -alt- (adipic acid)] (manufactured by Kuraray Co., Ltd., trade name: Kuraray polyol P-2010), 100 parts by weight, isophorone diisocyanate (Wako Pure Chemical Industries, Ltd.) 20 parts by weight of Reagent Co., Ltd., reagent) was charged into a three-necked flask equipped with a stirrer, a reflux condenser and a thermometer, and after substitution with nitrogen, polymerization was performed at 100 ° C. for 8 hours. While stirring, 210 parts by weight of methyl ethyl ketone was gradually added and cooled to 40 ° C. to obtain a methyl ethyl ketone solvent for urethane resin. Subsequently, a mixed solution of 8 parts by weight of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 100 parts by weight of methyl ethyl ketone and 50 parts by weight of 2-propanol was added, and 40 ° C. Then, methyl ethyl ketone was added to adjust the solid content to 20% by weight to obtain a binder resin solution.

[Preparation Example 1 of Polymer Antistatic Agent]
100 parts by weight of polyethylene glycol monomethacrylate (Nippon Yushi Co., Ltd., trade name: BLEMMER PE-350), 20 parts by weight of lithium perchlorate (manufactured by Wako Pure Chemical Industries, Ltd., reagent), hydroquinone (Wako Pure Chemical Industries, Ltd.) Reagents manufactured by Co., Ltd. 1 part by weight and 400 parts by weight of methyl ethyl ketone were introduced into a four-necked flask equipped with a stirrer, condenser, nitrogen inlet tube and thermometer, and the inside of the system was purged with nitrogen. Reacted. Stearyl methacrylate (Wako Pure Chemical Industries, Ltd., reagent) 20 parts by weight, n-butyl methacrylate (Wako Pure Chemical Industries, reagent, 20 parts by weight), azobisisobutyronitrile (Wako Pure Chemical) 1 part by weight of Kogyo Co., Ltd., reagent) was added and polymerized at 80 ° C. for 3 hours, and then methyl ethyl ketone was added to adjust the solid content to 20% by weight. The weight average molecular weight was about 300,000. A polymer antistatic agent solution having a lithium concentration of 0.8% by weight was obtained.

[Preparation Example 2 for Polymer Antistatic Agent]
60 parts by weight of polyethylene glycol having a weight average molecular weight of 1000 (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 40 parts by weight of polypropylene glycol having a weight average molecular weight of 600 (manufactured by Wako Pure Chemical Industries, Ltd., reagent), lithium perchlorate (Wako Pure Chemical Industries, Ltd., reagent) 15 parts by weight and methyl ethyl ketone 400 parts by weight were introduced into a four-necked flask equipped with a stirrer, condenser, nitrogen inlet tube, thermometer, and the inside of the system was purged with nitrogen. The reaction was carried out at 80 ° C. for 10 hours. 30 parts by weight of isophorone diisocyanate (manufactured by Wako Pure Chemical Industries, Ltd., reagent) and 1,8-diazabicyclo [5.4.0] undecene-7 (manufactured by San Apro Co., Ltd., trade name: DBU) 0.5 Part by weight is added, and the urethanization reaction is carried out at 80 ° C. for 4 hours, and further 20 parts by weight of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd., reagent), hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd., reagent) 0.2 parts by weight was added and an ester reaction was carried out at 60 ° C. for 4 hours. Further, 10 parts by weight of stearyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd., reagent), 5 parts by weight of n-butyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd., reagent), azobisisobutyronitrile (Wako Pure) 2 parts by weight of Yaku Kogyo Co., Ltd., reagent) was added and polymerized at 80 ° C. for 3 hours, then methyl ethyl ketone was added to adjust the solid content to 20% by weight, and the weight average molecular weight was about 100,000. A polymer antistatic agent solution having a lithium concentration of 0.6% by weight was obtained.

[Support Production Example 1]
A polyethylene terephthalate film (product name: Lumirror, melting point: 260 ° C.) having a wall thickness of 25 μm is used as a synthetic resin film, and a polyether urethane adhesive (manufactured by Toyo Morton Co., Ltd., product name: TM). -317) 60 parts by weight, polyisocyanate type curing agent (manufactured by Toyo Morton Co., Ltd., trade name: CAT-11B), 40 parts by weight, benzotriazole type ultraviolet absorber (Ciba Specialty Chemicals Co., Ltd., trade name) : Tinuvin-384-2) An adhesive coating consisting of 5 parts by weight was applied so that the dry solid content was 4 g / m ² and dried at 60 ° C. for 1 minute to form an adhesive layer that also served as an ultraviolet blocking layer. Provided. Surface of OTP base paper for printing paper having a wall thickness of 170 μm (Oji Paper Co., Ltd., Cobb water absorption: 24.8 g / m ² , basis weight: 175 g / m ² ) used as a paper material having water resistance. Then, the substrate was superposed on the back surface and pressure-bonded to obtain a water-resistant support having a 5-layer structure (PET film / adhesive layer / OTP base paper for photographic paper / adhesive layer / PET film) having a thickness of 220 μm.

[Support Production Example 2]
Polyethylene urethane adhesive (trade name: TM-317, manufactured by Toyo Morton Co., Ltd.) 60 parts by weight on a polyethylene terephthalate film (product name: Lumirror, melting point: 260 ° C.) having a wall thickness of 25 μm, 40 parts by weight of a polyisocyanate curing agent (trade name: CAT-11B, manufactured by Toyo Morton Co., Ltd.), a benzotriazole ultraviolet absorber (trade name: Tinuvin-384-2, manufactured by Ciba Specialty Chemicals Co., Ltd.) An adhesive paint consisting of 5 parts by weight was applied so that the dry solid content was 4 g / m ² , dried at 60 ° C. for 1 minute, and a synthetic paper having a wall thickness of 80 μm (trade name, manufactured by YUPO CORPORATION) : KPK-80, Cobb method water absorbency: 1 g / m ^2, a basis weight: 82g / m ²⁾ superposed on the front and back surfaces of, crimped, five-layer structure having a thickness of 135 .mu.m (P To obtain a support having a T film / adhesive layer / synthetic paper / adhesive layer / PET film) made of water-resistant.

[Examples 1-4, Comparative Examples 1-2]
Each of the electrophotographic recording papers of Examples 1 to 4 and Comparative Examples 1 to 2 was prepared according to the following procedure using the preparation examples, production examples, and materials shown in Table 1 in the composition shown in Table 2. .
While gently stirring methyl ethyl ketone with Cowles mixer, add each weighed pigment particle little by little to adjust the solids concentration to 20% by weight, then increase the rotation speed of Cowles mixer and stir for 30 minutes. A pigment dispersion was prepared. Next, the number of rotations of the cowless mixer is reduced, and a binder resin solution, a polymer antistatic agent solution, and a curing agent (thin diluted with ethyl acetate to a solid content of 20% by weight) are added to this dispersion in that order, and the mixture is left for 20 minutes. After stirring, coarse particles were removed through a 100-mesh filter to prepare a coating solution for the toner receiving layer.
The same coating solution was applied to one side of the support using a bar coater so as to have a predetermined coating amount (dry solid content) and dried for 1 minute in a dryer set at 70 ° C. Example and comparative electrophotographic recording papers were obtained.
Except for Example 3, the same procedure was applied on both the front and back sides to obtain an electrophotographic recording sheet having the same toner fixing layer on both sides.

[Test example]
The following tests were performed on the electrophotographic recording papers of Examples 1 to 4 and Comparative Examples 1 and 2. The results were as shown in Table 2. In all the electrophotographic recording sheets, the toner fixability in the toner receiving layer immediately after recording was good.

(Evaluation of recording quality)
Using a color laser printer (trade name: N4-612II, manufactured by Casio Co., Ltd.), four color colors of yellow, cyan, magenta and black are used for the toner receiving layer of the electrophotographic recording paper obtained in the above examples and comparative examples. Test image recording with toner was performed, and recording quality such as density, color tone, gradation, and the like was visually determined according to the following evaluation criteria.
○: The density, color tone, and gradation are all good.
Δ: The recording density is slightly low.
X: Density, color tone, or gradation is inferior and cannot be used.

(Evaluation with stickiness)
Using a color laser printer (manufactured by Casio Co., Ltd., trade name: N4-612II), 21 test images were continuously printed on the toner receiving layer of the electrophotographic recording paper obtained in the above Examples and Comparative Examples. Whether or not the eleventh sheet from the top can be pulled out by hand one minute after printing in the state of being overlaid on each other was determined according to the following evaluation criteria.
○: Can be pulled out by hand ×: Sticking between papers is so bad that it cannot be pulled out by hand

(Evaluation of water resistance)
The recording paper recorded in the above evaluation of recording quality is immersed so that it does not float in water (ion exchange water) filled in the bat, and after being immersed in water for 24 hours, the recorded image is strongly rubbed with a coin. Visual evaluation was made according to the evaluation criteria.
○: No change in recorded image.
X: Peeling occurs in the recorded image.

  As shown in Table 2, the electrophotographic recording paper of the present invention has good recording quality such as density, color tone, gradation, etc., does not cause sticking of paper due to charging when continuously printed, and has excellent water resistance. It was confirmed that

FIG. 3 is a partially enlarged cross-sectional view of one embodiment of the electrophotographic recording paper of the present invention. It is a partially expanded sectional view of the other aspect of the electrophotographic recording paper of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic recording paper 2 Toner receiving layer 3 Support body 4 Paper material 5 Synthetic resin film 6 Adhesive layer 7 Protective layer

Claims (21)

An electrophotographic recording paper provided with a toner-receiving layer containing a fat-soluble polymer antistatic agent on at least one surface of a water-resistant support, wherein the toner-receiving layer has a surface characteristic at a temperature of 25 ° C. and a relative humidity of 20%. An electrophotographic recording paper having a resistance value of 1 × 10 ^{7 to} 9 × 10 ¹² Ω.   2. The electrophotographic recording paper according to claim 1, wherein the polymer antistatic agent contains an alkylene oxide group and / or a hydroxyl group and an alkali metal ion. The electrophotographic recording paper according to claim 1 or 2, wherein the polymer antistatic agent has a structure represented by the following general formula (1).

(Wherein R ¹ and R ² each independently represents a hydrogen atom or a methyl group, R ³ represents a hydrogen atom, a chlorine atom or a methyl group, R ⁴ represents an alkyl group having 1 to 30 carbon atoms, A Is one type of linking group selected from the following <Group 1>, or one or more types of linking groups selected from the following <Group 1> and one or more types of linkage selected from the following <Group 2> Represents a linking group in which the groups are alternately bonded or a single bond,
<Group 1> An alkylene group having 1 to 6 carbon atoms which may have a substituent,
An arylene group having 6 to 20 carbon atoms which may have a substituent,
<Group 2> —CONH—, —NHCO—, —OCONH—, —NHCOO—,
-NH-, -COO-, -OCO-, -O-,
M represents an alkali metal, m represents an integer of 0 to 300, n represents an integer of 1 to 300, and p represents an integer of 1 to 100. )   4. The electrophotographic recording paper according to claim 2, wherein the toner receiving layer contains 0.01 to 1% by weight of alkali metal ions.   The electrophotographic recording paper according to claim 2, wherein the alkali metal ions are lithium ions.   6. The electrophotographic recording paper according to claim 1, wherein the toner receiving layer contains 1 to 50% by weight of a polymer antistatic agent and 10 to 99% by weight of a binder resin.   The electrophotographic recording paper according to claim 6, wherein the binder resin comprises polyether urethane, polyester urethane, polyacryl urethane, acrylic acid ester copolymer, or a mixture thereof.   The toner receptive layer is formed by applying an organic solvent solution paint containing the polymer antistatic agent and the binder resin to the surface of the support and drying it to form a film. The electrophotographic recording paper according to claim 6 or 7.   The electrophotographic recording paper according to any one of claims 1 to 8, wherein the support is formed by laminating a synthetic resin film on at least one side of a paper material having water resistance.   The electrophotographic image according to any one of claims 1 to 9, wherein the support is formed by laminating an ultraviolet blocking layer and a synthetic resin film in this order on at least one surface of a paper material having water resistance. Recording sheet. 11. The electrophotographic image according to claim 9, wherein the paper material having water resistance is a paper material having a water absorption of 0 to 50 g / m ² according to a Cobb method based on JIS-P-8140: 1998. Recording sheet.   The water-resistant paper material is selected from the group consisting of diazo photosensitive paper base paper, photographic printing paper base paper, resin-impregnated paper, resin-coated paper, sulfuric acid paper, pseudosulfuric paper, water-resistant paper, oil-proof paper, and waterproof paper. The electrophotographic recording paper according to claim 9, wherein the electrophotographic recording paper is a processed paper.   The electrophotographic recording paper according to any one of claims 9 to 11, wherein the paper material having water resistance is a polyolefin-based film containing inorganic and / or organic fine powder.   The electrophotographic recording paper according to any one of claims 9 to 13, wherein the synthetic resin film contains a thermoplastic resin having a melting point of 180 to 300 ° C.   The electrophotographic recording paper according to claim 14, wherein the thermoplastic resin used for the synthetic resin film is a polyester resin or poly (4-methylpent-1-ene).   The electrophotographic recording paper according to claim 15, wherein the polyester resin is polyethylene terephthalate.   The ultraviolet blocking layer contains at least one ultraviolet absorber selected from a group consisting of benzotriazole, benzophenone, salicylate, cyanoacrylate, nickel, and triazine. Item 17. The electrophotographic recording paper according to any one of Items 10 to 16.   The electrophotographic recording paper according to claim 17, wherein the content of the ultraviolet absorber used in the ultraviolet blocking layer is 1 to 50% by weight in the layer composition. The electrophotographic recording paper according to claim 1, wherein the electrophotographic recording paper has a capacitance of 10 to 300 pF / cm ² .   The electrophotographic recording paper which has an adhesive layer in one side of the outermost layer of the electrophotographic recording paper as described in any one of Claims 1-19.   A recorded matter using the electrophotographic recording paper according to any one of claims 1 to 20.

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