JP2012155097A - Electro-photographic paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electro-photographic paper that has excellent water resistance after image formation, and efficiently removes toner in deinking treatment.SOLUTION: The electro-photographic paper contains a soybean protein polymer.

Description

  The present invention relates to electrophotographic paper.

  Recognizing the importance of protecting forest resources from the viewpoint of protecting the natural environment of the entire planet, reducing the use of resources has become an important issue. As part of reducing resource use, paper used in copiers, printers, etc. is being reused. Examples of the reuse method include a method (deinking process) in which a printed matter on which toner is fixed by an electrophotographic apparatus is beaten against a fiber to remove the toner, and then paper is made again as paper.

  As the deinking process, a peeling method using a mechanical frictional force by a kneader, a peeling method by dissolving a part of paper using cellulase, and the like are examined. Methods (for example, see Patent Documents 1 to 8) have been studied.

  Moreover, the technique regarding the recycled paper containing alkali-soluble resin is disclosed from a waterproof viewpoint (for example, refer patent documents 9 thru | or 15).

Japanese Patent Laid-Open No. 9-241985 JP-A-8-146644 Japanese Patent Laid-Open No. 8-146643 JP-A-6-299489 JP-A-6-297810 JP-A-5-125684 JP 2001-303468 A JP 2001-214389 A JP 2006-104622 A Japanese Patent Laid-Open No. 6-166989 Japanese Patent Laid-Open No. 7-279093 JP-A-8-3896 JP-A-5-247894 Japanese Patent Laid-Open No. 7-119081 Japanese Unexamined Patent Publication No. 7-90799

  An object of the present invention is to provide an electrophotographic paper that has excellent water resistance after image formation and can efficiently remove toner during deinking.

The above-mentioned subject is achieved by the following present invention.
That is, the invention according to claim 1
An electrophotographic paper containing soy protein polymer.

The invention according to claim 2
^2. The electrophotographic paper according to claim 1, wherein the content of the soy protein polymer is 0.5 g / m ² or more and 5.0 g / m ² or less.

The invention according to claim 3
The electrophotographic paper according to claim 2, wherein the total content of the resin including other resins other than the soybean protein polymer is 5.0 g / m ² or less.

The invention according to claim 4
A paper substrate;
Covering the surface of the paper substrate on which an image is formed, and a surface layer containing the soy protein polymer;
The electrophotographic paper according to claim 1, comprising:

  According to the first aspect of the present invention, there is provided an electrophotographic paper that is excellent in water resistance after image formation and capable of removing toner efficiently during deinking treatment, compared to the case without this configuration. Is done.

  According to the second aspect of the invention, compared to a case where the content of the soy protein polymer is not within the range of the present configuration, the toner has excellent fixability and is efficiently removed during the deinking process. A possible electrophotographic paper is provided.

  According to the invention of claim 3, there is provided an electrophotographic paper excellent in toner fixability as compared with a case where the total content of resins including other resins other than soybean protein polymer is not within the range of this configuration. Provided.

  According to the fourth aspect of the present invention, there is provided an electrophotographic paper capable of efficiently removing toner during the deinking process as compared with the case where the soybean protein polymer is present in a dispersed state inside the electrophotographic paper. The

(A) is a schematic view of the electrophotographic paper according to the present embodiment in a state where a toner image is formed, and (B) is a schematic view of the electrophotographic paper according to the present embodiment in a state where a toner image is formed. It is the schematic shown in FIG. (A) to (D) are explanatory views for explaining a toner fixing property test.

Hereinafter, the present invention will be described in detail.
<Electrophotographic paper>
The electrophotographic paper according to this embodiment contains soy protein polymer.
The soybean protein polymer is desirably contained in an amount of 0.5 g / m ^{2 to} 5.0 g / m ² , and the total content of the resin including other resins other than the soybean protein polymer is 5.0 g. / M ² or less is desirable.

  The soy protein polymer is a protein obtained by hydrolyzing a defatted protein extracted from soybean so that the molecular weight (Mw) is in a range of 100,000 Dalton to 200,000 Dalton, and then 0.3% by mass concentration, 40 ° C., and pH 10 The polymer compound derived from soybean protein that has been carboxy-modified until 90% by mass or more of the total amount is dissolved.

The electrophotographic paper according to this embodiment is subjected to deinking processing when a recycled paper is manufactured after a toner image is recorded and used for a desired application. As the deinking process, a deinking method using an “alkaline solution containing a deinking agent” is used. For example, the deinking is performed by decomposing the toner into fibers using an alkaline solution containing a deinking agent and releasing the toner. A deinking process is performed through a process and a deinking process of separating the separated toner and deinking the toner from the electrophotographic paper disassembled into fibers. In the present embodiment, since the soybean protein polymer is contained, the toner is efficiently removed during the deinking process.
Although this action is not particularly clear, it is presumed that the toner fixed on the electrophotographic paper is also efficiently removed because the soybean protein polymer is dissolved by the alkaline solution.

-Content of soy protein polymer-
In addition, the soybean protein polymer is desirably contained in the electrophotographic paper according to this embodiment in the range of 0.5 g / m ^{2 to} 5.0 g / m ² as described above, and more preferably 0.75 g / m ² or more. 4.0 g / m ² or less is more desirable, and 1.0 g / m ² or more and 3.0 g / m ² or less is particularly desirable.
When the content of the soy protein polymer is 0.5 g / m ² or more and 5.0 g / m ² or less, the soy protein polymer is appropriately present inside the electrophotographic paper. The toner can be efficiently removed as compared with the case where the content of the soy protein polymer is not in this range. By being 0.5 g / m ² or more, the soybean protein polymer is sufficiently present on the surface on which the image is formed, and the toner removability is excellent. On the other hand, when the amount is 5.0 g / m ² or less, the surface is not excessively covered with resin, and when the toner is fixed, the effect of throwing the toner into the voids of the electrophotographic paper functions, and the toner fixing property is excellent.

-Total resin content including other resins other than soybean protein polymer-
In the electrophotographic paper according to this embodiment, the total content of resins including other resins than the soybean protein polymer is desirably 5.0 g / m ² or less, and more preferably 4.0 g / m ^2. m ² or less is more desirable, and 3.0 g / m ² or less is particularly desirable.
When the total resin content is 5.0 g / m ² or less, the resin is appropriately present inside the electrophotographic paper, so that the toner permeates into the electrophotographic paper properly during toner fixing, and the toner is fixed. The decline in sex is suppressed. In addition, the surface is not excessively covered with resin, and when the toner is fixed, the effect of throwing the toner into the voids of the electrophotographic paper functions, and the toner fixing property is excellent.
Here, in the conventional water-resistant paper, the resin is filled from the viewpoint of ensuring the water resistance, but in the present embodiment, the viewpoint of functioning the effect of throwing the toner into the gap of the electrophotographic paper, that is, the electronic From the viewpoint of photographic characteristics, it is desirable that the content of the soy protein polymer and other resins be in the above range.

-Mode in which soy protein polymer is contained-
The electrophotographic paper according to the present embodiment is an aspect having a paper base material and a surface layer that covers the surface of the paper base material on which an image is formed and includes the soy protein polymer. More desirable.

  That is, as shown in FIG. 1, it is more desirable that the surface of the paper base 52A on which the image is formed is covered with a surface layer 54 containing soy protein polymer. Due to this aspect, since the surface layer 54 is dissolved by the alkaline solution during the deinking process, the toner 40 having the deinking agent 60 attached to the surface is efficiently removed from the paper base 52A, In addition, it is assumed that the paper base 52A is swollen and decomposed into a fibrous paper component 52B.

-Smoothness-
Further, as described above, when the surface layer 54 containing the soy protein polymer covers the surface of the paper base 52A on which the image is formed, the surface layer 54 is further formed. The smoothness of the side surface is preferably 20 s or more and 180 s or less, more preferably 30 s or more and 150 s or less, and particularly preferably 40 s or more and 120 s or less.

  The smoothness is measured by the following method, and the numerical values described in this specification are measured by the method. In this specification, the Oken type smoothness is used as the smoothness, and Japan TAPPI No. 5 is measured using a Oken type smoothness air permeability tester (model name EY-5, manufactured by Asahi Seiko Co., Ltd.).

  The state in which the surface layer 54 does not fill the unevenness of the surface of the paper base 52A from the viewpoint of functioning the effect of throwing the toner into the voids of the electrophotographic paper when fixing the toner to the electrophotographic paper according to the present embodiment. From this point of view, it is desirable that the smoothness of the surface on which the surface layer 54 is formed be in the above range.

-Air permeability-
As described above, when the surface layer 54 containing the soy protein polymer covers the surface of the paper base 52A on which the image is formed, the air permeability of the electrophotographic paper is 7s or more. It is preferably 100 s or less, more preferably 10 s or more and 80 s or less, and particularly preferably 15 s or more and 60 s or less.

  In addition, the said air permeability is measured by the following method, and the numerical value as described in this specification is measured by this method. In this specification, the Oken type air permeability is used as the air permeability, and Japan TAPPI No. 5 is measured using a Oken type smoothness air permeability tester (model name EY-5, manufactured by Asahi Seiko Co., Ltd.).

  The state in which the surface layer 54 does not fill the unevenness of the surface of the paper base 52A from the viewpoint of functioning the effect of throwing the toner into the voids of the electrophotographic paper when fixing the toner to the electrophotographic paper according to the present embodiment. From the viewpoint, it is desirable that the air permeability of the electrophotographic paper is in the above range.

  In addition, as a method of controlling the smoothness and the air permeability within the above ranges, there is a method of forming the surface layer 54 thin, specifically, forming the surface layer 54 within the above-described content range.

-Alkaline solution containing deinking agent-
As described above, the electrophotographic paper according to this embodiment is subjected to a deinking process when a recycled paper is manufactured after a toner image is recorded and used for a desired application. As the deinking process, a deinking method using an “alkaline solution containing a deinking agent” is used. For example, the deinking is performed by decomposing the toner into fibers using an alkaline solution containing a deinking agent and releasing the toner. A deinking process is performed through a process and a deinking process of separating the separated toner and deinking the toner from the electrophotographic paper disassembled into fibers.
Here, as the deinking agent, for example, higher alcohol sulfate, polyoxyalkylene higher alcohol sulfate, fatty acid or fatty acid salt, alkylbenzene sulfonate, alkylene oxide adduct of higher alcohol and alkylphenol, polyhydric alcohol ester alkylene Examples include oxides, alkylene oxide adducts of higher fatty acids, ether compounds or ester compounds thereof, but are not particularly limited in the present embodiment.
Examples of the alkaline solution include sodium hydroxide, potassium hydroxide, sodium silicate, sodium carbonate, and the like. If the pH of the solution is in the range of 9.0 to 12.5, It doesn't matter. As the alkaline solution, one or more kinds may be used, or a plurality of kinds may be used in combination.

  Hereinafter, the configuration of the electrophotographic paper according to the present embodiment will be described.

(Paper substrate)
Examples of the paper substrate include commonly used recording paper such as plain paper and general printing paper. Specifically, for example, a material containing pulp fiber (and filler as necessary) as a main component may be used. In addition, examples of the paper base material used in the above-described embodiment include those in which pulp fibers are exposed on the surface on which the toner image is formed.

  The pulp fiber is a chemical pulp, specifically, hardwood bleached kraft pulp, hardwood unbleached kraft pulp, softwood bleached kraft pulp, softwood unbleached kraft pulp, hardwood bleached sulfite pulp, hardwood unbleached sulfite pulp, softwood bleached sulfite. In addition to pulp, softwood unbleached sulfite pulp, and the like, pulp made by chemically treating wood and fiber raw materials such as cotton, hemp, and leather are desirable.

  In addition, ground wood pulp that mechanically pulps wood and chips, chemimechanical pulp that has been mechanically pulped after chemicals have been soaked into wood and chips, and pulped with refiner after chips are softened to a little softness Also used are thermomechanical pulps and chemithermomechanical pulps that are characterized by high yields. These may be used only with virgin pulp, or waste paper pulp may be added as necessary.

  The virgin pulp is bleached mainly using ozone / hydrogen peroxide or the like without using chlorine gas and using chlorine dioxide (Elementary Chlorine Free: ECF) or without using any chlorine compound. What was bleach-processed by the method (Total Chlorine Free: TCF) is desirable. In addition, as raw materials of the waste paper pulp, unprinted waste paper such as cuts, damaged paper, widened white, special white, medium white, white loss, etc. generated in bookbinding, printing factories, cutting offices, etc .; printing and copying High-quality printed paper such as high-quality paper, high-quality coated paper, etc .; water-based ink, oil-based ink, old paper written with a pencil, etc .; printed high-quality paper, high-quality coated paper, medium-quality paper, medium-quality coated paper, etc. Newspaper waste paper including flyers; waste paper such as medium-quality paper, medium-quality coated paper, and reprint paper; may be used depending on the purpose.

  The waste paper pulp is preferably one obtained by treating the above-mentioned raw material with at least one of ozone bleaching treatment and hydrogen peroxide bleaching treatment. Moreover, it is desirable that the ratio of the waste paper pulp obtained by the bleaching treatment is 50 to 100% by mass. Further, it is more preferable that the ratio of the waste paper pulp is 70 to 100% by mass.

In addition to the pulp fiber, a filler may be added to the recording paper as necessary in order to adjust the opacity, whiteness and surface properties. When it is desired to reduce the halogen content, it is desirable to use a filler that does not contain halogen.
As the filler, heavy calcium carbonate, light calcium carbonate, chalk, kaolin, calcined clay, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, aluminum silicate, calcium silicate, magnesium silicate, Synthetic silica, aluminum hydroxide, alumina, sericite, white carbon, saponite, calcium montmorillonite, sodium montmorillonite, bentonite and other inorganic pigments, acrylic plastic pigments, polyethylene, chitosan particles, cellulose particles, polyamino acid particles, urea Examples thereof include organic pigments such as resins.

Further, when used paper pulp is added to the recording paper, it is necessary to estimate the ash contained in the used paper pulp raw material in advance and adjust the addition amount.
The blending amount of the filling amount is not particularly limited, but is preferably 1 to 80 parts by weight and more preferably 1 to 50 parts by weight with respect to 100 parts by weight of the pulp fiber.

(Soy protein polymer)
The soy protein polymer contained in the electrophotographic paper according to the present embodiment is not particularly limited. For example, soy protein polymer modified to have a cationic charge, soy protein polymer modified to have an anionic charge. And soy protein polymer modified to have both an anionic charge and a cationic charge.
Among these, a soy protein polymer modified to have both an anionic charge and a cationic charge is particularly desirable.

  The weight average molecular weight (Mw) of the soy protein polymer is preferably 100,000 or more and 200,000 or less, more preferably 110,000 or more and 180,000 or less.

  The weight average molecular weight is measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is carried out with a THF (tetrahydrofuran) solvent using a Tosoh GPC / HLC-8120 as a measuring device, using a Tosoh column / TSKgel, SuperHM-M (15 cm). The weight average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

Incidentally, soy protein polymer, it is desirable to include as the 0.5 g / ^{m 2} or more 5.0 g / ^{m 2} or less.

Moreover, in this embodiment, you may contain other resins other than the said soybean protein polymer. Examples of the other resin include oxidized starch, enzyme-modified starch, modified starch, derivatized starch, polyvinyl alcohol, and casein.
As described above, the total content of resins including other resins than the soybean protein polymer is desirably 5.0 g / m ² or less.

The electrophotographic paper according to the present embodiment contains the soy protein polymer, and as described above, the surface of the paper base 52A on which the image is formed is soy as shown in FIG. It is more desirable that the surface layer 54 containing the protein polymer is covered.
Further, when the surface layer 54 is formed, it is more desirable to have the above-described smoothness and air permeability requirements.

Here, a method for forming the surface layer 54 on the surface of the paper base 52A on which the image is formed will be described.
The method of forming the surface layer 54 is not particularly limited, and examples include a method of coating using a size press, a gate roll coater, an air knife coater, a blade coater, a bar coater, etc. Coating by is desirable.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

Example 1
[Method for producing recording sheet (A1)]
-Manufacture of a paper base material (medium waste paper) The pulp dispersion liquid was prepared so that pulp solid content might become 0.3% of medium-quality deinked pulp with a freeness of 380 ml. To this pulp dispersion, 100 parts of pulp solids contained in the pulp dispersion, succinic anhydride (ASA) internal sizing agent (Nippon NSC Co., Ltd., Fibran-81) is 0.3 parts. , Cationized starch (Cato-304 manufactured by Nippon SC Co., Ltd.) 0.5 part, and using an orientation paper machine for experiments made by Kumagai Riki, using 80 mesh wire, paper making speed 1600 m / min, paper stock Paper making was performed under conditions of a discharge pressure of 1.5 kg / cm ² . After that, the set was squeezed for 3 minutes at 10 kgf / cm ² with a press for Kumagaya Riki's square sheet machine, and then dried at 120 ° C. and 0.5 m / min on a KRK rotary dryer manufactured by Kumagai Riki. A paper base material (medium waste paper) having an amount of 67.5 g / m ² was obtained. The freeness of the paper base material (medium waste paper) was 380 ml.

-Formation of surface layer To this paper base material, the following surface size liquid is heated to 50 ° C, soy protein polymer content is 1.5 g / m ² , and total resin content is 2.3 g / m 2. After being size-pressed with a test size press manufactured by Kumagai Riki so as to be ² , it was dried at 120 ° C. and 1.0 m / min using a KRK rotary dryer manufactured by Rum Kumagai to obtain a recording paper (1). The basis weight was 70.0 g / m ² .
(Surface size liquid)
・ Oxidized starch (surface size binder,
Ace A) manufactured by Oji Cornstarch Co., Ltd. (in solid content) 100 parts, 10 parts of bow glass, surface sizing agent (manufactured by Arakawa Chemical Industries, Ltd., Polymaron 1355), 10 parts, soy protein polymer (manufactured by Dupont Soy Polymers,
Pro-Cote4200, Mw180,000) 200 copies
8% strength aqueous solution containing

-Example 2-
[Method for producing recording sheet (A2)]
The paper base used is changed to LBKP having a freeness of 480 ml (referred to as LBKP (1)), the surface size liquid is changed to the following, and the content of soybean protein polymer is 0.7 g / m ² . A recording paper was obtained by the method described in Example 1 except that the total resin content was changed to 0.74 g / m ² .
(Surface size liquid)
・ Bow glass 10 parts ・ Surface sizing agent (manufactured by Arakawa Chemical Co., Ltd., Polymeron 1355) 10 parts ・ Soy protein polymer (manufactured by Dupont Soy Polymers,
Pro-Cote 5000, Mw 110,000) 300 parts
2.6% strength aqueous solution containing

Example 3
[Method for producing recording sheet (A3)]
As described in Example 1, except that the surface sizing solution was changed to the following, and the content of the soy protein polymer was changed to 2.0 g / m ² and the total content of the resin was changed to 2.1 g / m ^2. Recording paper was obtained by the method described above.
(Surface size liquid)
・ Bow glass 10 parts ・ Surface sizing agent (manufactured by Arakawa Chemical Co., Ltd., Polymeron 1355) 10 parts ・ Soy protein polymer (manufactured by Dupont Soy Polymers,
Pro-Cote4200, Mw180,000) 300 copies
7.3% strength aqueous solution containing

Example 4
[Method for producing recording sheet (A4)]
The paper base used is changed to LBKP having a freeness of 380 ml (referred to as LBKP (2)), the surface size liquid is changed to the following, and the content of soy protein polymer is 3.2 g / m ² . Recording paper was obtained by the method described in Example 1 except that the total resin content was changed to 4.1 g / m ² .
(Surface size liquid)
・ Oxidized starch (surface size binder,
Ace A) manufactured by Oji Cornstarch Co., Ltd. (in solid content) 60 parts, 10 parts of bow glass, surface sizing agent (manufactured by Arakawa Chemical Co., Ltd., Polymaron 1355), 10 parts, soy protein polymer (manufactured by Dupont Soy Polymers,
Pro-Cote 5000, Mw 110,000) 240 parts
14.3% strength aqueous solution containing

-Example 5
[Method for producing recording sheet (A5)]
As described in Example 1, except that the surface sizing solution was changed to the following, and the content of the soy protein polymer was changed to 4.5 g / m ² and the total content of the resin was changed to 4.9 g / m ^2. Recording paper was obtained by the method described above.
(Surface size liquid)
・ Oxidized starch (surface size binder,
Ace A) manufactured by Oji Cornstarch Co., Ltd. (in solid content) 19 parts, 10 parts of bow glass, surface sizing agent (manufactured by Arakawa Chemical Co., Ltd., Polymaron 1355), 10 parts, soy protein polymer (manufactured by Dupont Soy Polymers,
Pro-Cote 5000, Mw 110,000) 281 parts
17% strength aqueous solution containing

-Example 6
[Method for producing recording sheet (A6)]
As described in Example 1, except that the surface size liquid was changed to the following, and the content of the soy protein polymer was changed to 2.9 g / m ² and the total content of the resin was changed to 5.2 g / m ^2. Recording paper was obtained by the method described above.
(Surface size liquid)
・ Oxidized starch (surface size binder,
Ace A) manufactured by Oji Cornstarch Co., Ltd. (in solid content) 130 parts, 10 parts of bow glass, surface sizing agent (manufactured by Arakawa Chemical Industries, Ltd., Polymaron 1355), 10 parts, soy protein polymer (manufactured by Dupont Soy Polymers,
Pro-Cote 5000, Mw 110,000) 170 parts
18% strength aqueous solution containing

-Comparative Example 1-
[Method for Manufacturing Recording Paper (B1)]
The paper base used is changed to the LBKP (2), the surface sizing solution is changed to the following, the soy protein polymer content is 0 g / m ² , and the total resin content is 2.2 g / m ^A recording paper was obtained by the method described in Example 1 except that it was changed to ² .
(Surface size liquid)
・ Bow glass 10 parts ・ Surface sizing agent (Arakawa Chemical Co., Ltd., Polymeron 1355) 10 parts ・ Urethane resin (Asia Kogyo Co., Ltd., WU-104) 300 parts
7.7% strength aqueous solution containing

-Comparative Example 2-
[Method for producing recording sheet (B2)]
The method described in Example 1 except that the surface sizing solution was changed to the following, and the content of the soy protein polymer was changed to 0 g / m ² and the total content of the resin was changed to 1.0 g / m ^2. Recording paper was obtained.
(Surface size liquid)
・ Oxidized starch (surface size binder,
Ace A) manufactured by Oji Cornstarch Co., Ltd. (in solid content) 270 parts, 10 parts of bow glass, surface sizing agent (manufactured by Arakawa Chemical Industries, Ltd., Polymaron 1355) 10 parts, 30 parts of aqueous titanium polymer
3.5% strength aqueous solution containing

-Comparative Example 3-
[Method for producing recording sheet (B3)]
The paper base used is changed to the LBKP (2), the surface size solution is changed to the following, the soy protein polymer content is 0 g / m ² , and the total resin content is 3.2 g / m ^A recording paper was obtained by the method described in Example 1 except that it was changed to ² .
(Surface size liquid)
・ 10 parts of bow glass ・ Surface sizing agent (manufactured by Arakawa Chemical Co., Ltd., Polymeron 1355) 10 parts ・ Water-based polyester resin (manufactured by Toyobo Co., Ltd., Vironal MD-1200) 300 parts
11.1% strength aqueous solution containing

-Comparative Example 4-
[Method for producing recording sheet (B4)]
The method described in Example 1 except that the surface sizing solution was changed to the following, and the content of the soy protein polymer was changed to 0 g / m ² and the total content of the resin was changed to 2.0 g / m ^2. Recording paper was obtained.
(Surface size liquid)
・ Bow glass 10 parts ・ Surface sizing agent (Arakawa Chemical Co., Ltd., Polymeron 1355) 10 parts ・ Polyethylene oxide (Meisei Chemical Industry Co., Ltd., Alcox) 300 parts
7% strength aqueous solution containing

  The basis weight, smoothness, and air permeability of the recording papers of the above Examples and Comparative Examples were measured by the above-described methods. The results are shown in Table 1 below.

[Evaluation method]
・ Evaluation method of recyclability Deinking and production of recycled paper were performed as follows and evaluated.
Using a DocuCentreColor f450 (manufactured by Fuji Xerox Co., Ltd., hereinafter referred to as “DCCf450”), each recording paper obtained in the examples and comparative examples was printed in a monochromatic black color with a printing area ratio of 10% and an electrophotographic image. The recording paper after output was chopped into 3 cm square.
A deinking agent (DI-7027 (manufactured by Kao Corporation)) is further added to an alkaline aqueous solution adjusted to pH 12 with sodium hydroxide so as to be 0.5%, and the pulp concentration is adjusted to 12% in the aqueous solution. The recording paper cut into 3 cm squares was put, and disintegrated for 20 minutes with a Tappi standard disintegrator under the condition of a temperature of 25 ° C. Next, this pulp liquid was diluted to 1%, 500 ml of the diluted pulp liquid was put into a 900 ml glass bottle with a lid, stirred for 10 minutes at 200 rpm with a lab shaker, allowed to stand for 1 minute, and the floating toner was discarded. Thereafter, the paper was filtered through a 15φ Buchner funnel to produce a recycled paper so that the paper basis weight after drying was 65 g / m ² to 70 g / m ² .
50 sheets of the regenerated paper were observed with a microscope or a scanner, the number of dirts of 0.004 mm ² or more was counted, the number of dirts per 1 m ^{2 of} paper was calculated, and evaluation was performed according to the following criteria.
○: Less than 10,000 pieces / m ² Δ: 10,000 pieces / m ² or more and less than 20,000 pieces / m ² ×: 20,000 pieces / m ² or more

Toner fixability evaluation method The fixability evaluation method uses the DCCf450 (manufactured by Fuji Xerox Co., Ltd.), and is output to each recording sheet obtained in the examples and comparative examples as shown in FIG. When the Pk 100% toner image portion 80 is bent along a fold line as shown in FIG. 4B and the bent portion is lightly rubbed with a Bencott 82 as shown in FIG. 4C, the Pk toner image is visually observed. It was confirmed whether or not toner separation on the surface occurred (see FIG. 4D), and the degree of occurrence was evaluated.
The measurement environment is a JIS environment (temperature 23 ° C., relative humidity 50% RH). The Pk toner image portion is an image portion expressing black with an image density of 100% for three colors Y, M, and C.
◎: No toner peeling occurred ○: The area ratio of the toner peeling portion is less than 5% of the area of the bent portion Δ: The area ratio of the toner peeling portion is 5% or more of the area of the bent portion

-Water resistance evaluation method Using the DCCf450 (manufactured by Fuji Xerox Co., Ltd.), an image is output in an electrophotographic manner with a printing area ratio of 100% in monochromatic black on each recording paper obtained in the examples and comparative examples. The recording paper after image output was cut into 3 cm square. Place one sheet of 3 cm square in a glass bottle with a lid together with 500 ml of an aqueous solution of pH 7 ± 0.3, stir at 200 rpm for 10 minutes with a lab shaker, let stand for 1 minute, and use tissue to cover the surface of the sheet. After wiping off the water, when it was rubbed lightly with a becot, it was visually confirmed whether or not toner peeling occurred on the image surface, and the degree of occurrence was evaluated.
○: No toner peeling occurred
Δ: The area ratio of the toner peeling portion is less than 5% in the total area of 3 cm square ×: The area ratio of the toner peeling portion is 5% or more in the total area of 3 cm square is shown in Table 1 below. Shown in

40 toner 50 electrophotographic paper 52A paper substrate 52B fibrous paper component 54 surface layer 60 deinking agent 80 toner image portion 82 Bencott

Claims (4)

  Electrophotographic paper containing soy protein polymer. ^2. The electrophotographic paper according to claim 1, wherein the content of the soy protein polymer is 0.5 g / m ² or more and 5.0 g / m ² or less. The electrophotographic paper according to claim 2, wherein the total content of resins including other resins than the soybean protein polymer is 5.0 g / m ² or less. A paper substrate;
Covering the surface of the paper substrate on which an image is formed, and a surface layer containing the soy protein polymer;
The electrophotographic paper according to claim 1, comprising: