JP2002088680A - Cut paper having coated layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cut paper exhibiting good traveling property in a copying machine, printer, printing machine, etc., good traveling property, especially, under high moisture, having high gloss of white paper suitable for obtaining high image quality and especially suitable for transfer paper for photography. SOLUTION: This cut paper is provided with a coated layer containing pigment and an adhesive on both sides of a substrate and has >=50% glossiness (according to JIS P-8142, in 75 deg. white glossiness). The cut paper is characterized in that frictional coefficient A (measured according to J TAPPI No.30) between papers in 35% RH at 22 deg.C and frictional coefficient B (measured according to J TAPPI No.30) between papers in 65% RH at 25 deg.C satisfy the following formulas: B-A<=0.35, A<=0.7 and B<=0.7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cut sheet suitable for feeding a stacked cut sheet one by one to an electrophotographic copying machine, a printer, a printing machine, and the like, and more particularly to running in a high humidity environment. The present invention relates to cut paper having excellent properties.

[0002]

2. Description of the Related Art In recent years, electrophotographic copying machines and printers have been improved in color, speed, and image quality. In particular, in the field of on-demand publications, there has been a remarkable movement to create publications that have been obtained by printing using color copiers and color printers, because it is easier and can handle small number of copies. It has become.

[0003] Coated paper having high white paper gloss is usually coated with a pigment having an average particle diameter of 2 µm or less at 10 g / m ² or more per one side of a base paper by various coaters and smoothed by calendering. Things. These high-gloss glossy coated papers have usually been used in the field of commercial printing, but also in the field of copiers and printers, in order to form vivid images, conventional PPC paper and printer paper were used. Instead, the use of the above-mentioned coated paper is increasing.

In general, a copying machine or a printer supplies cut paper to a printing unit from a tray inside the machine main body or a manual feed tray installed outside the main body. However, when high glossy coated paper for printing is passed in a high humidity environment such as during the rainy season, the paper comes into close contact with each other and cannot be supplied.

[0005] The inventors of the present invention have reported that these coated papers usually have a poorer water absorbing property than uncoated paper used in copiers and printers. It is considered that the water on the surface of the coating layer is not easily absorbed and adheres to the surface, and the surface tension of the water enhances the adhesion phenomenon between papers. It is considered that this phenomenon causes the paper to come into close contact with each other, thereby increasing the coefficient of friction between the papers and hindering travel.

Heretofore, as a method for improving the running property of coated paper, for example, an alkyl ketene dimer is applied to a paper as a friction reducing agent to reduce the frictional resistance between transfer papers, thereby improving the paper feeding. It has been proposed to prevent the traveling trouble of Japanese Patent Application Laid-Open No. 3-220560. This coated paper employs a means to directly reduce frictional resistance, which improves running performance under low humidity, but in high humidity environments causes the above-mentioned adhesion phenomenon and significantly reduces frictional resistance between transfer papers. It is thought that this resulted in an increase in travelability and, consequently, a decrease in running performance.

As a method for improving the running property in a high-humidity environment, Oken-type smoothness of coated paper (JTAPPI No.
It has been proposed to adjust 5) in 60 to 300 seconds and the air permeability in the range of 10 to 90 seconds (JP-A-8-17122).
No. 6), since the coated paper has a glossiness of blank paper lower than 50%, the glossiness of the blank paper portion and the image portion is high, and it is not possible to obtain a high image quality having a feeling of printing.

Further, in order to improve the running property in a high humidity environment, a method has been proposed in which both sides of a base paper are impregnated with a coating liquid containing an aqueous silicone oil having a reactive substituent (Japanese Patent Laid-Open No. Hei. JP-A-303847), the silicone oil in the base paper adheres to the roll surface of a printer or a copier, thereby affecting the running property, and the attached silicone oil may deteriorate the image quality, thereby obtaining high image quality. Doesn't seem to be the right method.

Further, it has been proposed to suppress the air permeability and swelling of the paper to improve the running property in a high humidity environment (Japanese Patent Application Laid-Open Nos. 11-160906 and 11-1).
If the swelling of the paper is suppressed to such an extent that the above-mentioned adhesion phenomenon can be sufficiently avoided, the formation of the paper becomes poor, and high image quality cannot be obtained.

[0010]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned drawbacks of the conventional coated paper, and provides a full-color copier, a monochrome copier, a printer, and a printer of an indirect dry electrophotographic system. It is intended to provide cut paper having good blank paper gloss, suitable for obtaining high image quality, and particularly suitable for electrophotographic transfer paper, in which the runnability of cut paper such as, for example, is excellent, especially in high humidity. Is what you do.

[0011]

SUMMARY OF THE INVENTION The present invention has been made as a result of intensive studies to solve the above problems of coated paper having high blank paper gloss and high smoothness. We succeeded in providing cut paper that also has runnability, especially cut paper suitable for electrophotographic transfer paper. The configuration of the present invention is as follows.

(1) Cut paper having a coating layer containing a pigment and an adhesive on both surfaces of a base material and having a glossiness (JIS P-8142, 75-degree white glossiness) of 50% or more is 22%.
Coefficient of friction A between papers at 35 ° C and 35% RH (J TAPP
I No. 30 and RH 65% at 25 ° C.
Coefficient B between sheets (J TAPPI No. 30)
Cut paper characterized by satisfying the following formula: B−A ≦ 0.35 A ≦ 0.7 B ≦ 0.7

(2) Oken-type smoothness (J
TAPPI No. 2) 300 seconds or more
The cut paper according to the above (1), wherein the cut paper has a duration of 000 seconds or less. (3) The cut paper as described in (1) or (2) above, wherein the cut paper has a center line average roughness of 0.1 μm or more and 0.7 μm or less measured by a surface shape measuring microscope.

(4) A cut sheet characterized by using the cut sheet according to any one of the above (1) to (3) as an electrophotographic transfer sheet.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors did not directly aim at reducing the coefficient of friction between sheets, but did not directly apply the sheet tension due to the surface tension of moisture adhering to the sheet surface under the high humidity of coated paper. By suppressing the increase in the coefficient of friction between the sheets, that is, by controlling the surface properties of the coated paper, it was possible to secure good running properties in a high-humidity environment even on coated paper having a high glossiness of white paper. .

The present invention has succeeded in securing the above characteristics by suppressing the adhesion parameter defined by the following equation to a specific value or less in a coated paper having a blank glossiness of 50% or more. Adhesion parameter = BA ≦ 0.35 where B is the coefficient of friction between paper at 25 ° C. and 65% RH, and A is the coefficient of friction between paper at 22 ° C. and 35% RH.

FIG. 1 illustrates the relationship between the adhesion parameter and the degree of glossiness of a blank sheet. In the figure, the relationship between the above-mentioned relationship and the examples and comparative examples described later is shown. In the above equation, since 22 ° C. and 35% RH are low in humidity, the surface tension of adsorbed water hardly affects the friction coefficient between sheets.
At 5 ° C. and 65% RH, the humidity is high, and the surface tension of the water between the sheets greatly affects the coefficient of friction between the sheets. The adhesion parameter (BA) is 25 ° C., 65% RH and the friction coefficient between papers B and 2
This is a difference from the friction coefficient A between 2 ° C. and 35% RH between papers. If the friction coefficient B between high-humidity 25 ° C. and 65% RH between papers is large, the adhesion parameter also becomes large, which causes misfeed or double feed.

The inventors of the present invention have made intensive studies on these relationships. As a result, stable running properties can be obtained for the first time by setting the adhesion parameter to 0.35 or less in a coated paper having a blank glossiness of 50% or more. I found something. If the adhesion parameter is larger than 0.35, troubles such as double feed and misfeed occur, and stable paper supply cannot be performed. Further, it has been found that by setting both the friction coefficient B between paper at 25 ° C. and 65% RH and the friction coefficient A between paper at 22 ° C. and 35% RH at 0.7 or less, more stable running properties can be secured.

As described above, the coefficient of friction between high gloss coated papers sharply increases in a high humidity environment. The reason for this is
Generally, high-gloss coated paper has a smooth surface, the contact area between the papers when the paper is deposited is larger than that of low-gloss coated paper and uncoated paper, and mixed between papers in a high humidity environment The surface tension caused by the moisture is higher in high gloss coated paper than in low gloss coated paper or uncoated paper. Therefore, in order to stabilize the running property in a high humidity environment, it is necessary to reduce the contact area of the coated paper. According to this request, it is necessary to reduce the smoothness of the paper surface, but generally, when the smoothness is reduced, the glossiness of a blank sheet, which is a feature of the high gloss coated paper, is reduced, so that good image quality is obtained. Unable to do so and lose commercial value.

Therefore, the present inventors paid attention to the surface structure of the coated paper. FIG. 2 shows a model of the cross-sectional structure of a general high gloss coated paper (a), a coated paper (b) of the present invention, and an uncoated paper (c) from a macroscopic viewpoint and a microscopic viewpoint. It is a representation. When the cross sections of the papers of (b) and (c) are compared, they have almost the same rough shape macroscopically, but when viewed microscopically, (c) has a very rough surface, but (b) Indicates that the surface is smooth. Comparing the cross sections of (a) and (b), the surface of (b) is macroscopically rough, but microscopically almost the same as (a) and very smooth.

Therefore, although the surface structure is close to high gloss coated paper microscopically, it has microscopic roughness within a range that does not reduce the glossiness, and macroscopically, it can be applied to uncoated paper. By providing a near surface structure, it is possible to lower the coefficient of friction between papers in a high humidity environment while maintaining a high blank paper glossiness, and it is possible to ensure good running performance in a high humidity environment. .

Therefore, the present invention provides a method of smoothing the Oken type (J T
APPI No. 5) in the range of 300 seconds or more and 2000 seconds or less, and the center line average roughness of the paper surface is 0.1 μm or more and 0.1 μm or more.
By adjusting the thickness to 7 μm or less, it is possible to provide cut paper having good running properties in a high-humidity environment while having a blank glossiness of 50% or more.

The Oken type smoothness is less than 5 seconds if it is less than 300 seconds.
When the glossiness of the white paper is 0% or more, the adhesion parameter cannot be maintained at 0.35 or less when the glossiness is higher than 2000 seconds. Therefore, good running property in a high humidity environment cannot be secured. The preferable range of Oken type smoothness is 500
It is not less than seconds and not more than 1500 seconds.

Further, the center line average roughness of the paper surface is 0.1.
If it is smaller than 1 μm, the smoothness of the paper surface cannot be controlled,
If it is larger than 0.7 μm, blank glossiness of 50% or more cannot be maintained. The preferred range of the center line average roughness of the paper surface is 0.45 μm or more and 0.70 μm or less.

The center line average roughness of the paper surface was measured using a surface shape measuring microscope (manufactured by Keyence Corporation). The surface roughness was measured in the CD direction of the paper, the paper surface was enlarged 2500 times (measurement length was 1105 μm), the measurement pitch in the Z direction was 0.01 μm, and the Z-direction stage movement amount was 30 μm. In addition, the average value of the numerical values obtained by measuring an arbitrary point having no scratch five times was used as the center line average roughness.

The pulp used for the base paper of the coated paper of the present invention is not particularly limited, but the pulp used for the base paper of ordinary general coated paper, for example, LBKP, NBK
P, GP, PGW, RMP, TMP, CTMP, CM
Chemical pulp such as P or CGP or mechanical pulp can be used alone or in combination.

In the base paper according to the present invention, a filler is used in order to improve coating suitability and to adjust opacity and whiteness after coating. Examples of fillers usable here include heavy calcium carbonate, light calcium carbonate, kaolin, calcined clay, pyroloferrite, sericite, silicates such as talc, and inorganic fillers such as titanium dioxide, and urea resins and styrene. And the like, but not limited thereto. The amount of these fillers is not particularly limited, but is suitably in the range of 3 to 20% by mass, more preferably 5 to 15% by mass.

Further, various chemicals such as a sizing agent used for the base paper of the present invention can be used by internal addition or external addition. Types of sizing agents include rosin-based sizing agents, synthetic sizing agents, petroleum resin-based sizing agents, sizing agents such as neutral sizing agents, sulfate bands, cationized starch, and the like.
It may be used in combination with a suitable fixing agent. From the viewpoint of ensuring the paper preservability after copying in electrophotographic copying machines, printers, etc., neutral sizing agents, for example, alkenyl succinic anhydride sizing agents, alkyl ketene dimer, alkenyl ketene dimer, neutral rosin, petroleum It is preferable to use a sizing agent, an olefin resin, a styrene / acrylic resin, or the like.

In an electrophotographic transfer paper, sodium chloride, potassium chloride,
Inorganic materials such as calcium chloride, sodium sulfate, zinc oxide, titanium dioxide, tin oxide, aluminum oxide, magnesium oxide, etc., alkyl phosphate esters, alkyl sulfates, sodium sulfonates, quaternary ammonium salts, etc. Organic materials can be used alone or as a mixture. In addition, paper strength agents, dyes,
Various auxiliaries, such as a pH adjuster, that are blended in a normal coated paper base paper can be used as appropriate.

The pigment used for the coating layer of the coated paper of the present invention includes pigments used for ordinary general coated papers, for example, heavy calcium carbonate, light calcium carbonate, titanium dioxide, aluminum hydroxide, satin white. , Talc, calcium sulfate, barium sulfate, zinc oxide, magnesium oxide, magnesium carbonate, amorphous silica, colloidal silica, white carbon, kaolin, calcined kaolin, delaminated clay, aluminosilicate, sericite,
Mineral pigments such as bentonite and smectite, polystyrene resin fine particles, urea formaldehyde resin fine particles,
Fine hollow particles, other organic pigments and the like can be used alone or in combination.

Examples of the adhesive used in the present invention include various copolymers such as styrene / butadiene, styrene / acrylic, ethylene / vinyl acetate, butadiene / methyl methacrylate, and vinyl acetate / butyl acrylate. Alcohol, maleic anhydride copolymer,
Synthetic adhesives such as acrylic acid / methyl methacrylate copolymers, natural starches such as oxidized starch, esterified starch, enzyme-modified starch, and cold-water-soluble starch obtained by flash-drying them, casein, soy protein, etc. A generally known adhesive can be used.

These adhesives are used in an amount of 5 to 50 parts by weight, more preferably 10 to 30 parts by weight, per 100 parts by weight of the pigment. If necessary, various auxiliaries, such as a dispersant, a thickener, a water retention agent, a defoaming agent, and a water-proofing agent, which are blended in a general pigment for coated paper, can be used as appropriate.

The method for applying the coating composition according to the present invention to the surface of a substrate is carried out by using, for example, a blade coater, an air knife coater, a roll coater, a reverse roll coater, a bar coater, a curtain coater, a die slot coater, a gravure coater and the like. On- or off-machine coating is performed on the surface of the base material in one or more layers. The coating amount is suitably in the range of 8 to 50 g / m ^{2 on} one side by dry weight.

For the smoothing treatment after the coating, a commonly used smoothing device, for example, a super calender, a machine calender, a soft nip calender, or the like is used. Finish the smoothness within the range of 300 seconds or more and 2000 seconds or less.

The moisture content of the product immediately after opening is 4-6.
It is adjusted to 5% by a paper machine, a drier of a coater, a calendar process, or the like. In addition, in order to prevent moisture absorption and desorption during storage, the package is wrapped with moisture-proof wrapping paper such as polyethylene laminated paper or a polypropylene film.

In the specific production of the coated paper of the present invention, for example, a base paper having a low surface smoothness is used, and a fine pigment having a high particle diameter having a high glossiness is used to form the coated paper. Use a method of obtaining a microscopically smooth surface, or a method of using a pigment with a fine particle size, such as an air knife coater or a roll coater, to macroscopically roughen the surface after coating. Can be.

[0037]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

(Example 1) Freeness 420 ml CS
F (Canadian Standard Freeness) to a hardwood kraft pulp (LBKP) slurry beaten to a concentration of 10% by weight of light calcium carbonate (Okutama Kogyo Co., Ltd., TP-121).
2 parts by weight of starch, 1.5 parts by weight of a rosin sizing agent and 2 parts by weight of a sulfuric acid band were added, and paper was made using a fourdrinier paper machine. Then, oxidized starch (Oji Cornstarch Co., Ltd., Ace A) was applied in an amount of 2.0 g by dry weight.
/ M ² by a size press device, dried, and then machine-calendered to Oken-type smoothness (J TAP).
PI No. 5) was subjected to a smoothing treatment to be 10 seconds to obtain a base paper having a basis weight of 80 g / m ² .

Light calcium carbonate (Okutama Industry Co., Ltd., TP-123) is 30 parts by weight and kaolin (Engelhard Co., Ltd.) is used for 100 parts by weight of the pigment component of the coating composition to be coated on the base paper. , Ultra White 90), 15 parts by weight of organic pigment (Nippon Zeon Co., Ltd., OP-84J), 3 parts by weight of oxidized starch (Oji Cornstarch Co., Ltd., Oji Ace B) as an adhesive The above coating composition containing 12 parts by weight of an adhesive (Nippon Synthetic Rubber Co., Ltd., JSR0696) and 0.4 part by weight of a dispersant (Toa Gosei Co., Ltd., Aron T-40) was mixed with after the coating amount was coated on both surfaces of the base paper by a blade coater so that the 13 g / m ^2, performs a smoothing process so that the white paper gloss supercalendered of 50 ° C. metal roll temperature of 60% To obtain the amount 106 g / m ² of transfer paper for electrophotography.

Example 2 Light calcium carbonate (Okutama Kogyo KK, TP-222H) was added to 100 parts by weight of the pigment component of the coating composition to be applied to the base paper of Example 1.
80 parts by weight of kaolin (Engelhard Co., Ultra White 90), 3 parts by weight of oxidized starch (Oji Cornstarch Co., Ltd., Oji Ace B) as an adhesive and a synthetic adhesive (Nippon Synthetic Rubber Co., Ltd.) ), JSR066
8) and 12 parts by weight of a dispersant (Toa Gosei Co., Ltd., Aron T-40) were blended so that the coating amount per side was 13 g / m ^2. After coating both sides of the base paper with a blade coater, the glossiness of white paper was 6 using a soft nip calender with a metal roll temperature of 100 ° C.
A smoothing process is performed so that the weight becomes 0%, and the basis weight is 106 g / m.
Electrophotographic transfer paper No. ² was obtained.

Example 3 LBKP (Freeness (CS
F) = 350 ml), 10% by weight of light calcium carbonate (Okutama Kogyo Co., Ltd., TP-121)
2 parts by weight of starch, 1.5 parts by weight of a rosin sizing agent, and 2 parts by weight of a sulfuric acid band per 100 parts by weight of the pulp slurry, and papermaking is performed using a fourdrinier paper machine. Oxidized starch (Oji Cornstarch Co., Ltd., Ace A) was applied to this wet paper at a dry weight of 2.0 g.
/ M ² using a size press, dried, and then machine-calendered using Oken-type smoothness (J TAP).
A smoothing treatment was performed so that PI No. 5) became 30 seconds, to obtain a base paper having a basis weight of 75 g / m ² .

The base paper is coated with 30 parts by weight of light calcium carbonate (Okutama Kogyo KK, TP-123) and kaolin (Engelhard Co., Ltd.) with respect to 100 parts by weight of the pigment component of the coating composition. , Ultra White 90), 25 parts by weight of organic pigment (Zeon Corporation, OP-84J), and 3 parts by weight of oxidized starch (Oji Cornstarch Co., Ltd., Oji Ace B) as an adhesive The above coating composition containing 12 parts by weight of an adhesive (Nippon Synthetic Rubber Co., Ltd., JSR0696) and 0.4 part by weight of a dispersant (Toa Gosei Co., Ltd., Aron T-40) was mixed with After coating both sides of the base paper with an air knife coater so that the coating amount becomes 15 g / m ² , a smoothing treatment is performed by using a super calender with a metal roll temperature of 50 ° C. so that the glossiness of white paper becomes 65%. Tsubo To obtain an electrophotographic transfer paper of 105g / m ^2.

Example 4 In Example 1, the basis weight of the base paper was 102 g / m ² , the coating amount per side of the coating composition was 26 g / m ² , and the basis weight was 128 g / m ² . Except for the above, an electrophotographic transfer paper was obtained in the same manner as in Example 1.

Comparative Example 1 Using the base paper of Example 3, 3 parts of light calcium carbonate (TP-123, Okutama Kogyo Co., Ltd.) was added to 100 parts by weight of the pigment component of the coating composition to be coated.
0 parts by weight, 70 parts by weight of kaolin (Engelhard Co., Ultra White 90), 3 parts by weight of oxidized starch (Oji Cornstarch Co., Ltd., Oji Ace B) as an adhesive, and a synthetic adhesive (Nippon Synthetic Rubber (Japan Synthetic Rubber) Co., Ltd.), JSR066
The above coating composition containing 11 parts by weight of 8) and 0.3 part by weight of a dispersant (Toa Gosei Co., Ltd., Aron T-40) was blended so that the coating amount per side was 15 g / m ^2. Is coated on both sides of the base paper with a blade coater, and then subjected to a smoothing treatment using a super calender having a roll temperature of 50 ° C. so that the glossiness of the white paper becomes 60%, and a transfer paper for electrophotography having a basis weight of 105 g / m ^2. I got

Comparative Example 2 A commercial printing coated paper OK Super Art (Oji Paper Co., Ltd.) having a basis weight of 127.9 g / m ² was used as the electrophotographic transfer paper of Comparative Example 2.

COMPARATIVE EXAMPLE 3 A commercially available printing coated paper OK Topcoat (Oji Paper Co., Ltd.) having a basis weight of 127.9 g / m ² was used as the electrophotographic transfer paper of Comparative Example 3.

(Comparative Example 4) A commercially available printing coated paper NK High Coat having a basis weight of 104.7 g / m ² (Nippon Kaishi Paper Co., Ltd.) was used as the electrophotographic transfer paper of Comparative Example 4.

Comparative Example 5 A commercially available coated paper for printing, Roston (Oji Paper Co., Ltd.) having a basis weight of 157.0 g / m ² was used as the electrophotographic transfer paper of Comparative Example 5.

(Comparative Example 6) A commercial printing coated paper having a basis weight of 127.9 g / m ² NK Tokusatsu Art (Nippon Kaishi Paper Co., Ltd.) was used as the electrophotographic transfer paper of Comparative Example 6. .

Comparative Example 7 A commercially available NPi coat for printing paper having a basis weight of 127.9 g / m ² (Nippon Paper Industries Co., Ltd.) was used as the electrophotographic transfer paper of Comparative Example 7.

(Comparative Example 8) A commercial printing coated paper OK Coat L (Oji Paper Co., Ltd.) having a basis weight of 72.3 g / m ² was used as the electrophotographic transfer paper of Comparative Example 8.

<Quality Evaluation Method> (1) Basis Weight: Measured according to the method of JIS P-8124. (2) Blank paper glossiness: Angle 7 according to JIS P-8142
Measured at 5 degrees. (3) Smoothness: Oken type smoothness (J TAPPI No.
Measured according to 5).

(4) Center line average roughness: The center line average roughness of the paper surface was measured using a surface shape measuring microscope (manufactured by Keyence Corporation). The measurement direction of the surface roughness is the CD direction of the paper, and the surface of the paper is 2500 times (measurement length is 1).
105 μm), and the measurement pitch in the Z direction is 0.0
The measurement was performed at 1 μm and the Z-direction stage movement amount was 30 μm. In addition, an average value obtained by measuring an arbitrary point having no scratch five times was used as the center line average roughness.

(5) Coefficient of friction between sheets: The measurement of the coefficient of friction between sheets and the change in the present invention is described in J. Org. TAPPI
No. According to No. 30, the measurement was performed as follows. Approximately 30 sheets of A4 size paper immediately after opening the packaging were collected and used as the test pieces, while being stacked at the time of opening. However, in order to eliminate other factors, once loosen the paper in advance,
The measurement was performed after the air existing between the sheets was evacuated. The weight for measurement used was 240 g in weight, 63 mm in width, and 75 mm in length. Test environment is 25 ℃ 65% RH and 22 ℃
At 35% RH, continuous 20 sheets were measured in the longitudinal direction of the paper. The moving speed of the weight at that time was 150 mm / min.

(6) Number of running troubles: The running performance of the transfer paper was evaluated using a dry indirect electrophotographic digital color copying machine Docucolor 1250 manufactured by Fuji Xerox Co., Ltd.
The test was performed at 5 ° C. and 65% RH. The paper sample is
Immediately after opening the package, place it on the bypass tray of the copier.
00 sheets were run, and the total number of occurrences of misfeeds, paper jams and double feeds during that time was counted as the number of running troubles. The evaluation criteria were the following four levels. ：: Misfeed, paper jam, double feed does not occur at all. ○: Slight misfeeding, paper jam, double feed occurs,
No problem in practical use. X: Misfeed, paper jam, and double feed frequently occur. XX: Misfeeds, paper jams, and double feeds that make traveling impossible.

[0056]

[Table 1]

(Evaluation) As is clear from Table 1, the cut sheets of Examples 1 to 4 all had the adhesion parameter of 0.3.
5, and according to the microscopic observation of the cross section of the paper, FIG.
Since it has a surface structure as shown in FIG.
%, No trouble occurred in a running test in a high humidity environment.

On the other hand, the cut sheets of Comparative Examples 1 and 4 have almost the same blank glossiness as those of Examples 1 to 4, but have high adhesion parameters of 0.56 and 0.41 and a smoothness of 3500. Seconds and 2100 seconds, a running test in a high-humidity environment caused misfeeds, paper jams, and heavy running, making traveling impossible. The cut sheets of Comparative Examples 2, 3, 6, and 7 are commercially available general coated papers. These adhesion parameters were very high, and traveling under high humidity was impossible. Although the cut sheet of Comparative Example 5 had a low adhesion parameter of 0.34, the coefficient of friction at 25 ° C. and 65% was as high as 0.89, and trouble frequently occurred. The glossiness of blank paper was 3.3, which was a very low value. The cut sheet of Comparative Example 8 has an adhesion parameter of 0.44.
, The runnability was somewhat poor, and the white paper glossiness was a low value of 49.

FIG. 1 shows the relationship between the adhesion parameter and the glossiness of the cut sheets of Examples 1 to 4 and the cut sheets of Comparative Examples 1 to 8. The solid line in FIG. 1 shows the average positional relationship of the conventional cut paper, and it can be seen that the coated paper of the present invention is located at a position completely different from that of a commercially available coated paper.

[0060]

According to the present invention, by adopting the above-described structure, in spite of the high glossiness of white paper in cut papers such as indirect dry electrophotographic full-color copying machines, monochrome copying machines, printers and printing machines, etc. In addition, it has an unprecedented excellent running performance under high humidity, and has made it possible to provide cut paper particularly suitable for transfer paper for electrophotography.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a close contact parameter of a cut sheet and a glossiness of a blank sheet according to the present invention.

FIG. 2 is a macro view and a micro view of a section of a general high gloss coated paper, coated paper of the present invention, and uncoated paper.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryosuke Nakanishi 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Tomoyoshi Tokiyoshi 1-10-6 Shinonome, Koto-ku, Tokyo Oji Paper Company Shinonome Research Center (72) Inventor Masaru Kato 1-10-6 Shinonome, Koto-ku, Tokyo Oji Paper Co., Ltd. Shinonome Research Center F-term (reference) 4L055 AA03 AC06 AG12 AG27 AG48 AG63 AG76 AG89 AH01 AH02 AH37 AJ01 AJ04 BE02 BE09 EA11 EA12 EA19 FA11 FA12 GA11

Claims (4)

[Claims] 1. A cut sheet having a coating layer containing a pigment and an adhesive on both surfaces of a base material and having a glossiness (JIS P-8142, 75-degree white glossiness) of 50% or more, at 22 ° C.
Coefficient of friction A between sheets at 35% RH (J TAPPI
No. Cut paper characterized in that the coefficient of friction B between papers at 25 ° C. and 65% RH (measured according to J TAPPI No. 30) satisfies the following formula: B−A ≦ 0.35 A ≦ 0.7 B ≦ 0.7 2. The Oken-type smoothness (JT) of the cut paper.
APPI No. 5) 300 seconds or more and 20
2. The cut sheet according to claim 1, wherein the cut sheet has a duration of 00 seconds or less. 3. The cut sheet has a center line average roughness of 0.1 μm or more and 0.7 μm measured by a surface shape measuring microscope.
3. The cut sheet according to claim 1 or 2, wherein m is equal to or less than m. 4. A cut sheet using the cut sheet according to claim 1 as an electrophotographic transfer sheet.