JPH11160906A - Electrophotographic transfer paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic transfer paper not causing lap sending and paper jamming, excellent in running performance and giving high image quality. SOLUTION: Coating layers contg. a pigment and an adhesive are formed on both faces of a paper substrate and the thickness increase of the resultant electrophotographic transfer paper by immersion in water at 20 deg.C is controlled to <=30 μm. The internal bonding strength of the transfer paper stipulated by J. TAPPI No.54-93 is controlled to <=0.27 kJ/m<2> and the gas permeability is also controlled to <=6,000 sec.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer paper which can be applied to electrophotographic monochrome and color copiers or printers, and which can record high-quality images comparable to prints. And a transfer paper for electrophotography which is excellent in running property.

[0002]

2. Description of the Related Art In elaborate multicolor printing represented by offset printing or the like, a paper base is provided with a coating layer mainly composed of a pigment and an adhesive on a paper base in order to improve printability. Coated paper such as art paper and coated paper (hereinafter referred to as printing paper) is used. On the other hand, in electrophotography,
With the recent generalization of DTP and the advance of electrophotographic technology, dramatic improvement in image quality and speeding up of printing have been realized, and it has been attempted to use the above-mentioned commercially available printing paper. With paper, double feed or paper jam in the recording device occurs at the time of feeding of prints, and / or the phenomenon that the image portion is swollen at the time of fixing toner, that is, the appearance is significantly reduced due to the occurrence of blisters, At present it is rarely used.

[0003] Regarding the transferability of transfer paper in a printer, double feed and paper jam of commercially available print paper occur particularly immediately after they are opened in a high-humidity environment and the package of print paper is opened and printing is started. Because of its easiness, the conventional printing paper has high smoothness and therefore high mutual adhesion, and the moisture adhering to the surface of the pigment coating layer has been considered to be the cause of the above-mentioned problems. As a countermeasure, Japanese Patent Publication No. 5-82939 discloses that a paint containing a pigment having low water adhesion and an adhesive is applied to base paper to reduce the standard deviation of the static friction coefficient between transfer papers to 0.05 or less. This proposal, which has been proposed,
Although there is an effect on the running property in an environment of 0 ° C. and 65% RH, the effect of improving the running property is not recognized in a high humidity environment (for example, 28 ° C. and 85% RH).

Regarding the cause of blister generation, it is considered that since the fixing of the toner is performed by heat treatment, the steam in the coated paper rapidly expands during this heat treatment, and blisters (blisters) occur in the image area. . As a means for dealing with this blister, JP-A-5-241366 discloses that a specific pigment coating layer is provided at a coating amount of ³ to 7 g / m ² on a substrate having a specific range of air permeability. Degree 40
It has been proposed to be less than 00 seconds. However, when the coating amount is 3 to 7 g / m ² , the coating of the paper substrate with the coating layer is insufficient, and a texture similar to that of a general printed matter cannot be obtained.
If the air permeability is less than 4000 seconds, the blister cannot be completely suppressed. Accordingly, there is a strong demand for an electrophotographic transfer paper having excellent running properties and free from blisters.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and eliminates the occurrence of double feeding and paper jams in an electrophotographic system, and provides good running performance. Another object of the present invention is to provide a transfer paper for electrophotography which does not generate blisters at the time of fixing and can obtain a high-quality image.

[0006]

Means for Solving the Problems The present inventors have developed an electrophotographic apparatus.
If the transfer paper has excellent running properties and blisters are not generated
As a result of intensive research on means to provide the characteristics described above,
An electrode having a coating layer mainly composed of a pigment and an adhesive on its surface.
Immerse it in water at 20 ° C on transfer paper for photo
Then, immediately after pulling up, the thickness increase immediately after
0 μm or less; TAPPI No. 54-
The internal bond strength measured according to 93 is 0.27 kJ / m
^TwoAnd the air permeability is 6000 seconds or less
The above problems were solved successfully by adjusting
Was. That is, the electrophotographic transfer paper according to the present invention is
Material and both sides, and mainly composed of pigment and adhesive
Immersed in water at 20 ° C
Immediately when pulled up, the thickness increase immediately after that is 30μ
m or less. TAPPI No. According to 54-93
Internal bond strength measured 0.27 kJ / m ^TwoAbove
And the air permeability is 6000 seconds or less.
It is a sign. Further, the electrophotographic roller according to the present invention.
The paper base of copying paper is immersed in water at 20 ° C and pulled immediately.
When it is raised, the thickness increase immediately after that
And J. TAPPI No. Measured according to 54-93
Internal bond strength 0.27 kJ / m^TwoThat's all
Is preferred.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have earnestly studied the relationship between double feed in a high-humidity environment, the occurrence of paper jams, the swelling of coated paper in the thickness direction with respect to humidity, and the coefficient of static friction. As a result of repeated investigations, it was found that multi-feeding and paper jams in high-humidity conditions occur when coated paper stacked on the paper feed tray absorbs moisture and swells in the thickness direction, increasing the adhesion between papers. I found it. That is, by preventing the swelling of the coated paper in the thickness direction under the high humidity condition, the running property under the high humidity environment was improved. In addition, regarding the occurrence of blisters generated during toner fixing, as a result of repeated studies on the relationship between the internal bonding strength of coated paper and paper base, air permeability,
It has been found that a sudden change in the volume of water at the time of toner fixing causes the base layer of the coated paper to swell. That is, by increasing the internal bond strength of the coated paper and setting the air permeability within a predetermined range, it was possible to obtain an electrophotographic transfer paper free of blister generation.

In the transfer paper for electrophotography according to the present invention,
Immediately after being immersed in water at 20 ° C. and pulled up, if the increase in thickness immediately after the immersion exceeds 30 μm, double feed, paper jam, etc. will occur, and the runnability will decrease. If the internal bond strength is lower than 0.27 kJ / m ^2, blisters may occur during toner fixing.

In order to make the swelling property and the internal bond strength in the thickness direction of the coated paper within the desired ranges, the present invention particularly reduces the moisture absorption swelling in the thickness direction of the paper substrate and reduces the internal bond strength. Suggest ways to enhance. In the electrophotographic transfer paper of the present invention, when immersed in water at 20 ° C. and immediately pulled up, the increase in thickness immediately after that is 30 μm or less, preferably 20 μm or less.
And J. TAPPI No. It is desirable to use a paper substrate having an internal bond strength of at least 0.27 kJ / m ² , preferably 0.3 kJ / m ² , measured according to 54-93.

In order to control the swelling of the paper substrate in the thickness direction with respect to the humidity, it is necessary to improve the dimensional stability of the paper substrate. In general, the fibers in a paper sheet expand and contract in the width direction according to the water content, and the dimensional change in the width direction is transmitted to the longitudinal axis of the fiber that intersects the fiber through inter-fiber bonding. Gives a longitudinal extension force. Here, the elongation of the fiber in the longitudinal axis direction is hindered to some extent by the rigidity in the fiber axis direction, but eventually slightly elongates. As a result of these developments, the dimensions of the paper change.
In paper, since the fibers are arranged substantially parallel to the paper surface, the dimensional change in the thickness direction is significantly larger than that in the plane direction.

Methods for improving the dimensional stability of the paper substrate include, for example, selection of the type of pulp (high-rigidity softwood pulp), use of heat-treated pulp, enhancement of fiber-to-fiber bonding by advancing beating, and paper. Additives (polyamide, acrylamide, amine compounds, etc.), wet paper strength enhancers (polyamides, epoxies, melamine compounds, etc.) and water repellents (natural wax, olefin, zirconium, fluorine wax), hydrophobic fibers (Glass fiber, etc.), water repellent and water-based resin (polyvinyl alcohol, fluorine resin, acrylic, styrene, acryl-styrene copolymer, amide, urethane, epoxy compound, etc.)
, Coating, lamination, lamination, etc. are effective, and these are appropriately selected and used according to the purpose.

In order to improve the internal bond strength of the paper substrate, for example, selection of the type of pulp (high-rigidity softwood), improvement of fiber-to-fiber bonds by beating, addition of paper strength agent, and resin Impregnation, coating, etc., but are appropriately selected according to the purpose.

The electrophotographic transfer paper of the present invention forms a coating layer by applying a coating liquid mainly composed of a pigment and an aqueous binder on both surfaces of the paper substrate, and performs a smoothing treatment thereon. Obtained by: Examples of coating layer pigments include heavy calcium carbonate, light calcium carbonate, kaolin, calcined kaolin, structural kaolin, delamikaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, alumina, magnesium carbonate, Mineral pigments such as magnesium oxide, silica, magnesium aluminosilicate, finely divided calcium silicate, finely divided magnesium carbonate, finely divided light calcium carbonate, white carbon, bentonite, zeolite, sericite, smectite, and polystyrene resin, styrene-acrylic Polymeric resins, urea resins, melamine resins, acrylic resins, vinylidene chloride resins, benzoguanamine resins, and organic pigments such as fine hollow particles and through-hole resins thereof, and one or more of these can be appropriately selected. It used Te.

As the adhesive for the coating layer, a water-soluble and / or water-dispersible polymer compound can be used.
For example, starches such as cationic starch, amphoteric starch, oxidized starch, enzyme-modified starch, thermochemically modified starch, esterified starch, etherified starch, cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, gelatin, casein, soybean Natural or semi-synthetic polymer compounds such as proteins and natural rubber, polydienes such as polyvinyl alcohol, isoprene, neoprene and polybutadiene, polyalkenes such as polybutene, polyisobutylene, polypropylene and polyethylene, vinyl halide, vinyl acetate, styrene, (meta ) Acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, vinyl-based polymers and copolymers such as methyl vinyl ether, styrene-butadiene-based, methyl methacrylate-butadiene-based synthetic rubber latex, Polyurethane resins, polyester resins, polyamide resins, olefin - maleic acid resins, and synthetic polymer compounds such as melamine resin. One or two or more of these are appropriately selected and used in accordance with the quality target of the electrophotographic thermal transfer paper.

[0015] In the coating liquid for forming a coating layer, the mixing ratio of the adhesive is 5 to 5 parts by weight per 100 parts by weight (solid content) of the pigment.
It is in the range of 0 parts by weight (solid content). If the amount is less than 5 parts by weight, the strength of the coating film obtained is low, and the coating layer is peeled off by the feed roll in the copying machine and deposited on the roll, causing slippage of the feed roll and damaging the transfer paper. On the other hand, if it exceeds 50 parts by weight, the occurrence of blocking between paper sheets and the denseness of the coating layer will reduce the penetration of the toner into the coating layer, and the toner layer will be easily peeled off.

In the coating liquid, in addition to the pigment and the adhesive, various auxiliaries such as a surfactant, p-
H adjuster, viscosity adjuster, softener, gloss imparting agent, wax, dispersant, flow modifier, antistatic agent, stabilizer, antistatic agent, crosslinker, sizing agent, fluorescent brightener, colorant , UV absorber, defoamer, waterproofing agent, plasticizer, lubricant, preservative,
It is also possible to appropriately use a fragrance or the like.

The coating amount of the coating liquid is appropriately selected according to the purpose of use of the electrophotographic transfer paper of the present invention, but generally, it completely covers the irregularities on the surface of the substrate. It is necessary that the amount is about 8 to 40 g / m ² in terms of dry weight. As a coating method for forming a coating layer, generally known coating apparatuses, for example, a blade coater, an air knife coater, a roll coater, a reverse roll coater, a bar coater, a curtain coater, a die coater, a gravure coater, a champlex coater, a brush coater, Apparatuses such as a two-roll or metering blade type size press coater, bill blade coater, short dwell coater, gate roll coater and the like are appropriately used.

The coating layer is formed on both sides of the paper substrate, and may have a multi-layer structure by providing one or more intermediate layers as necessary. In the case of a double-sided coating or a multilayer structure, it is not necessary that each coating liquid is the same or the coating amount is the same, and they may be appropriately adjusted and blended according to a required quality level. It is not limited. The coating layer provided on the back surface of the paper substrate is provided with a synthetic resin layer, a coating layer composed of a pigment and an adhesive, and an antistatic layer to prevent curling, impart printability, and adjust paper supply. Can also be given. Further, it is of course possible to use the transfer paper with additional applicability by subjecting the back surface of the transfer paper to various post-processing such as adhesion, magnetism, flame resistance, heat resistance, water resistance, oil resistance, and anti-slip.

In the present invention, after the coating layer is provided on the paper substrate, the moisture content is 3 to 10% by weight, preferably 4 to 8% by weight, by a smoothing treatment such as a usual drying step or surface treatment step.
Finished by adjusting to the extent.

The smoothing process is performed by a normal smoothing device such as a super calender, a gloss calender, or a soft calender. The smoothing process is appropriately used in an on-machine or an off-machine, and the form of the pressurizing device, the number of pressurizing nips, heating and the like are appropriately adjusted according to a normal smoothing process device.

The transfer paper which has been subjected to the smoothing treatment preferably has a preferable appearance and texture as a printing paper. For this reason, the glossiness of the white paper at an incident / reception angle of 75 degrees according to JIS Z8741 is 50% or more. Preferably, it is at least 55%. Further, the air permeability is preferably adjusted to 6000 seconds or less, more preferably 3000 seconds or less. By the way, if the air permeability exceeds 6000 seconds, blisters may be generated.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should be understood that the scope of the present invention is not limited by these Examples. In the examples, “parts” and “%” indicate “parts by weight” and “% by weight” unless otherwise specified.

Example 1 An electrophotographic transfer paper was prepared by the following steps. [Preparation of base material] LBKP (freeness (CSF) = 55
0 ml) 50 parts, NBKP (freeness (CSF) = 5
50%) 50% pulp slurry, 0.2% of polyacrylamide resin (trade name; PS194-7, manufactured by Arakawa Chemical Industry Co., Ltd.) as a paper strength agent, and polyamide / epichlorohydrin resin (trade name; as a wet strength agent) WS57
0, manufactured by Nippon PMC Co., Ltd.) and 1 part of a sulfuric acid band, and the mixture was diluted with white water to have a pH of 5.3.
A stock slurry having a solid content of 1.1% was prepared. The stock slurry is paper-made using a fourdrinier paper machine, and then a size press solution having a concentration of 1% of a fluororesin (trade name: FP-110, manufactured by Sumitomo Chemical Co., Ltd.) as a water repellent is applied. It is applied by a size press so as to have a dry weight of 0.5 g / m ² and dried. The paper is subjected to a smoothing treatment by a machine calender so as to have a Beck smoothness of 40 seconds and a basis weight of 80 g / m 2. ² base paper was obtained. Table 1 shows the increase in the thickness of the paper substrate due to the water immersion and the internal bond strength of the paper base paper.

[Preparation and application of coating liquid] Kaolin (trade name; manufactured by UW-90 Engelhard Co.) 60 parts by weight (solid content; the same applies hereinafter), light calcium carbonate (trade name: Brilliant S15 manufactured by Shiraishi Calcium Co., Ltd.) To 30 parts by weight and 10 parts by weight of calcined kaolin (trade name Ansilex Engelhard), sodium polyacrylate (trade name ARON A-9 manufactured by Toagosei Co., Ltd.) 0.2 as a dispersant
(Solid ratio to pigment; the same applies hereinafter), and the mixture was dispersed in water using a Cores disperser to prepare a pigment slurry. 3.0 parts by weight of oxidized starch (trade name; Ace A, manufactured by Oji Cornstarch Co., Ltd.) and styrene-butadiene copolymer latex (trade name: OX) are added to this pigment slurry.
1060 (manufactured by Nippon Zeon Co., Ltd.), stirred, and then water was added to prepare a coating liquid having a solid concentration of 40%.

[Formation of Coating Layer on Paper Substrate] The obtained coating liquid was applied to both sides of the above paper substrate with a dry weight of 15 per side.
g / m ² using an air knife coater, dried, and passed through a pressure nip composed of a metal roll and an elastic roll.
The surface was adjusted so that the glossiness of white paper at a light receiving angle of 75 ° was 55%, and a transfer paper having a basis weight of 110 g / m ² was produced.

[Evaluation of Transfer Paper] The air permeability of the obtained transfer paper and the running property and image recording when Acolor 935 (manufactured by Fuji Xerox Co., Ltd.) were used were evaluated. The results are shown in Table 2.

Example 2 A transfer sheet was prepared and evaluated in the same manner as in Example 1. However, the pulp freeness (CSF) was changed to 390 ml.

Example 3 A transfer sheet was prepared and evaluated in the same manner as in Example 2. However, a pulp slurry was prepared using 85 parts of LBKP and 15 parts of NBKP.

Comparative Example 1 [Preparation of Base Material] LBKP (Freeness (CSF) = 39
0 ml) 85 parts, and NBKP (freeness (CSF)
= 390 ml) to a pulp slurry containing 15 parts, 1.5 parts of a rosin emulsion sizing agent, 0.5 part of cationized starch
And 2 parts of a sulfuric acid band, and the mixture was diluted with white water to prepare a stock slurry having a pH of 5.3 and a solid content of 1.1%. Paper is made from this stock slurry using a Fourdrinier machine, and oxidized starch (trade name; ACE A) is added to the wet paper.
A size press liquid having a concentration of 6% (manufactured by Oji Corn Starch Co., Ltd.) was applied by a size press so that the application amount was 2.0 g / m ² in terms of dry weight, dried, and the obtained paper was machined. The paper was subjected to a smoothing treatment by a calender so that the Bekk smoothness became 40 seconds, to produce a base paper having a basis weight of 80 g / m ² .

[Preparation and Coating of Coating Liquid] Transfer paper was prepared and evaluated in the same manner as in Example 1. However, the above substrate was used.

Comparative Example 2 [Preparation of base material] LBKP (freeness (CSF) = 39
0 ml) 85 parts, and NBKP (freeness (CSF)
= 390 ml) To a pulp slurry containing 15 parts, 1 part of a sulfuric acid band was added and the mixture was diluted with white water to give p
A stock slurry having an H of 5.3 and a solid concentration of 1.1% was prepared. This paper stock slurry is paper-made using a fourdrinier paper machine, and the obtained wet paper is then coated with a water-repellent agent, a fluororesin (trade name: FP-110, manufactured by Sumitomo Chemical Co., Ltd.) at a liquid concentration of 1%. Press liquid was applied at a dry weight of 0.5 g / m ^2.
The resulting paper was subjected to a surface smoothing treatment with a machine calender so that the Beck smoothness was 40 seconds, and the basis weight was 8%.
A base paper of 0 g / m ² was prepared.

[Preparation and Application of Coating Liquid] Transfer paper was prepared and evaluated in the same manner as in Example 1. However, the above-mentioned base paper was used.

Example 4 [Preparation of base material] A paper base was produced in the same manner as in Example 1. However, in preparing the pulp slurry, 0.2% of a paper strength agent polyacrylamide resin (trade name: PS194-7 manufactured by Arakawa Chemical Industries) and a wet paper strength agent polyamide / epichlorohydrin resin (trade name: WS570 Nippon PMC)
Instead of 0.2% and 1 part of a sulfuric acid band, 0.5% of polyacrylamide resin (trade name; PS194-7, Arakawa Chemical Industry Co., Ltd.) and polyamide-epichlorohydrin resin (trade name: WS570) (Manufactured by Japan PMC)
0.5%, and as a size press treatment liquid, an oxidized starch (trade name; Ace A Oji Cornstarch) instead of the water repellent fluororesin (trade name; FP-110, manufactured by Sumitomo Chemical Co., Ltd.) Co., Ltd.) and a size press liquid having a concentration of 6% was applied by a size press device so that the amount of application was 2.0 g / m ² in terms of dry weight to prepare a paper substrate.

[Preparation and Coating of Coating Liquid] Transfer paper was prepared and evaluated in the same manner as in Example 1. However, the above paper substrate was used.

Example 5 A paper substrate was produced in the same manner as in Example 4. However, the size press treatment liquid was changed to water. The preparation, application and smoothing of the coating liquid were performed in the same manner as in Example 1 to obtain and evaluate transfer paper.

Example 6 [Preparation of base material] LBKP (freeness (CSF) = 39
0 ml) 85 parts, and NBKP (freeness (CSF)
= 390 ml) to a pulp slurry containing 15 parts, 3.0 parts of a rosin emulsion sizing agent, and a polyamide / epichlorohydrin resin (trade name: WS57) as a wet paper strength agent.
0 0.5 parts by PMC Japan, a polyethylene wax emulsion as a water repellent (trade name: SPW-10)
9, Arakawa Chemical Industry Co.) and 0.8 parts of sulfuric acid band, and the mixture was diluted with white water to obtain a pH of 5.5.
3. A stock slurry having a solid concentration of 1.1% was prepared. The stock slurry is made using a Fourdrinier paper machine, and the obtained paper is subjected to a smoothing process using a machine calender so that the Beck smoothness becomes 40 seconds, and a base paper having a basis weight of 80 g / m ² . Was prepared. The transfer paper was prepared and evaluated in the same manner as in Example 1 for the preparation and application of the coating liquid and the smoothing treatment.

Example 7 [Preparation of base material] LBKP (freeness (CSF) = 50
0 ml) To 100 parts of pulp slurry, 0.05 part of alkenyl succinic anhydride (trade name: Fibran 81) and cationized starch (trade name; Kate F manufactured by Oji National Co., Ltd.)
1.2 parts and 0.4 parts of a sulfuric acid band were added, and the mixture was diluted with white water to prepare a stock slurry having a pH of 7.0 and a solid content of 1.1%. The stock slurry is paper-made using a fourdrinier paper machine, and the obtained paper is subjected to a smoothing treatment by a machine calender so as to have a Beck smoothness of 40 seconds, and has a basis weight of 78 g / m ² . Paper was made. Furthermore,
Polyvinyl alcohol (trade name; PV
A117K (Kuraray Co., Ltd.) in a 5% aqueous solution using a bar coater so that the absolute dry weight of the coating layer per side is 1 g / m ² to obtain a paper substrate having a basis weight of 80 g / m ^2. Was. Transfer paper was prepared and evaluated in the same manner as in Example 1 for the preparation and application of the coating liquid, and the smoothing treatment.

Comparative Example 3 A paper substrate was produced in the same manner as in Example 7. However, the basis weight after the size press treatment was 80 g / m ² , and no polyvinyl alcohol was applied. Using this paper substrate,
A transfer sheet was prepared and evaluated in the same manner as in Example 7.

Comparative Example 4 A transfer sheet was prepared and evaluated in the same manner as in Example 7. However, in the production of the paper substrate, the basis weight was 80 g /
An m ² paper substrate was made.

Comparative Example 5 A transfer sheet was prepared and evaluated in the same manner as in Example 7. However, in the preparation of the paper base material, the basis weight of the base material was 72 g / m ^2.
A 5% aqueous solution of polyvinyl alcohol (trade name: PVA117K, manufactured by Kuraray Co., Ltd.) was applied on both sides of this substrate by a bar coater, and the absolute dry weight of the coating layer per side was 4 g / m.
² to produce a paper substrate having a basis weight of 80 g / m ² .

The transfer paper produced in each of the above Examples and Comparative Examples was subjected to the following measurements and evaluations. The measuring method and the evaluation method are shown below. The results are shown in Tables 1 and 2.

[Measurement of Increase in Thickness of Paper Substrate and Transfer Paper] A sample having a width of 1 cm and a length of 10 cm was prepared, and the sample was conditioned at 20 ° C. and 65% RH.
The thickness (C1) was measured. The conditioned sample was immersed in water at 20 ° C., immediately taken out, and immediately
The surface of the sample was wiped off with a filter paper so that the luster of the water disappeared, and the thickness (C2) was measured. Increase in thickness = C2-C1 (μm)

[Measurement of Internal Bonding Strength of Paper Substrate and Transfer Paper] TAPPI No. 54-93
Followed.

[Measurement of Air Permeability of Transfer Paper] TAPP
I No. According to the measuring method of 5-93, it was measured with an Oken-type air permeability meter (air micrometer).

[Measurement of Glossiness of Transfer Paper] Glossiness was measured under the conditions that the incident angle and the light receiving angle were 75 degrees. Measuring instrument: trade name GLOS METER MODEL GM-26D
(Murakami Color Research Laboratory)

[Evaluation of Runnability and Blister] Printer: Acolor935 (manufactured by Fuji Xerox Co., Ltd.)

(Evaluation of Runnability) Environment I: 20 ° C.-65% RH II: 28 ° C.-85% RH In the above environments I and II, 1000 sheets were recorded, and the number of double feeds and paper jams was measured. Evaluation was made according to the following evaluation criteria. ◎: The number of occurrences of double feeding and paper jam is 0. There is no practical problem and the quality is excellent. ：: The number of occurrences of double feed and paper jam is 1 to 5 times. No problem in practical use. Δ: The number of occurrences of double feed and paper jam is 6 to 10 times. There is a practical problem. X: The number of occurrences of double feed and paper jam is 11 or more. There is a problem in practical use, and the quality is extremely poor.

(Evaluation of Blister) Environment I: 20 ° C.-65% RH II: 28 ° C.-85% RH In the above-mentioned environments I and II, 100 sheets were recorded, the number of blister occurrences was measured, and the following evaluation criteria were used. evaluated. ：: The number of blister occurrences was 0. ：: The number of blisters generated is 1 to 5 times. Δ: The number of blisters generated is 6 to 10 times. X: Blister generation frequency is 11 times or more.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

The transfer paper for electrophotography according to the present invention is an electrophotographic transfer paper excellent in running properties, free of blisters and capable of recording high-quality images, and is extremely useful in practice.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryosuke Nakanishi 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. Inside

Claims (2)

[Claims] 1. A paper base material, comprising a coating layer formed on both surfaces thereof and containing a pigment and an adhesive as main components,
When immersed in water at 20 ° C. and immediately pulled up, the increase in thickness immediately after that was 30 μm or less. TAPPI
No. The internal bond strength as measured by 54-93 is 0.
27 kJ / m ² or more and its air permeability is 6000
A transfer paper for electrophotography, wherein the transfer time is less than seconds. 2. When the paper substrate is immersed in water at 20 ° C. and immediately pulled up, the increase in thickness immediately after that is 30 μm.
And J. TAPPI No. 2. The electrophotographic transfer paper according to claim 1, wherein the internal bond strength measured according to 54-93 is 0.27 kJ / m ² or more.