JP3003373B2 - Transfer paper for electrophotography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer sheet used for an indirect electrostatic copying machine or an indirect electrostatic printer.

[0002]

2. Description of the Related Art Recent changes in copiers and printers have been remarkable, and various functions such as increase in copy speed, downsizing, double-sided copy and multiple copy have been enhanced, and have spread widely to models having relatively low copy speed. I have. As a result, the number of paper feeds in the lateral direction has increased, and the paper has been conveyed through a complicated machine, and the conditions have become more and more severe for the paper. The term “lateral direction” as used herein means that the long side of the paper coincides with the paper advancing direction (vertical direction of the paper) in papermaking at the time of manufacturing, and means the direction parallel to the short side, that is, the horizontal direction of the paper, which is generally referred to as the longitudinal direction. I do. In electrophotographic transfer papers, generally vertical papers are often used.

Conventional office paper, such as transfer paper for electrophotography, is high-quality paper made mainly of bleached virgin pulp. However, these papers are not reused and become paper garbage. However, there is a demand for the reuse of office waste paper, but there is a difficult problem in the recovery, and a sufficient amount of waste paper that can be used has not been collected. Therefore, used newspaper paper currently collected as office paper is used, and further use thereof is desired. However, if recycled paper made from used newspaper is used as a raw material for indirect electrophotographic copiers, troubles such as wrinkling of copies and paper jams occur frequently, especially in copying work in a high-humidity environment. It has become clear that there are major obstacles. Particularly in copy work in a high-humidity environment, electrophotographic transfer paper containing waste newspaper pulp is less stiff in the horizontal direction than electrophotographic transfer paper using bleached virgin pulp as the main raw material, resulting in poor copy discharge. Troubles such as poor sorter accommodation, transfer drum peeling failure, and paper breakage in the fixing section have occurred. However, similar to the physical properties of conventional bleached virgin pulp electrophotographic transfer paper, recycled paper is generally used in an environment (temperature 2) specified by JIS P-8111.
0 ° C humidity 65% R. H. ), And the paper properties in that environment are not managed in spite of the fact that trouble is likely to occur in a high humidity environment.

[0004] An electrophotographic paper containing waste paper is disclosed in Japanese Patent Publication No. 63-6867, but the means for solving the problems such as the running property of paper absorbed in a high humidity environment as described above are as follows. Not presented. In order to solve the problem caused by the curl after copying, Japanese Patent Application Laid-Open No. Hei.
No. 2 discloses a difference between the expansion and contraction ratios of the front and back sides of the paper, and JP-A-3-243953 discloses means for specifying the residual curvature. However, means for solving problems such as running properties of paper absorbed in a high-humidity environment are as follows. Not presented.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, the present invention has been made to provide recycled paper having electrophotographic aptitude and containing a large amount of mechanical pulp such as used newspaper. It was done. Accordingly, an object of the present invention is to provide an electrophotographic transfer paper (hereinafter, referred to as a transfer paper) using a conventional bleached virgin pulp as a main material and having an electrophotographic suitability including a trouble such as a paper jam in a copying operation under a high humidity environment. 70) in all pulp
An object of the present invention is to provide transfer paper for electrophotography (hereinafter referred to as transfer recycled paper) containing at least 30% waste paper pulp and having a mechanical pulp ratio of at least 30%.

[0006]

The recycled paper for transfer of the present invention contains 70% or more of waste paper pulp in all pulp, the ratio of mechanical pulp is 30% or more, and the temperature is 25 ° C and the humidity is 85% R. . H. Paper with transverse Clark stiffness of the paper is 25 cm ^3/100 or more in an environment of
Is in the range of 98 μm to 110 μm . Furthermore, transfer recycled paper of the present invention, the following longitudinal wave propagation velocity ratio 1.40 ultrasonic pulse, ash 5% or less
A major feature is that by setting the value below, the electrophotographic aptitude which is no different from that of the conventional transfer paper is maintained.

The present inventors have paid attention to the fact that the characteristics in an environment where a trouble actually occurs are not controlled, and the paper under high humidity environment (temperature of 25 ° C. and humidity of 85% RH) is used. The relationship between various characteristics and troubles was energetically investigated. As a result, the Clark stiffness in the horizontal direction (measured according to JIS-P-8143) when the humidity was adjusted in the above environment for 2 hours or more was 25 cm.
If the ^3/100 or more was found to be able to significantly improve the trouble under the above-mentioned environment. Further, at this time, the inventors of the present invention have confirmed that when the used paper mixing ratio exceeds 70%, the Clark stiffness in the lateral direction sharply decreases (see FIG. 1).
The left lateral Clark stiffness recycled paper rate was maintained electrophotographic suitability even 70% or more 25 cm ^3/10
As a result of diligent efforts in research into technologies to reduce the pulsation rate to 0 or more, the ratio of longitudinal velocity of ultrasonic pulses to 1.40 or less and ash content to 5% or less (J
IS-P-8128), temperature 25 ° C, humidity 85% R.P.
H. Paper thickness of 98 to 110 when conditioned for 2 hours or more under the environment
If it was μm (measured according to JIS-P-8118), it was confirmed that the above conditions were satisfied, and the present invention was completed.

The details of the present invention are described below. In the present invention, “longitudinal wave propagation velocity ratio of ultrasonic pulse” means a value represented by the following equation. Ratio of longitudinal wave propagation velocity of ultrasonic pulse = ultrasonic propagation velocity in machine direction (MD) / ultrasonic propagation velocity in cross direction (CD) The “machine direction (MD)” means the flow direction of the paper machine. The "cross direction (CD)" means a direction perpendicular to the flow direction of the paper machine. The longitudinal wave propagation velocity ratio of the ultrasonic pulse in the present invention can be obtained by the measuring method shown in FIG. That is, thickness 10m
The sample 2 is placed on the rubber plate 1 with a bubble having a thickness of 150 m
The transmitting oscillator 3 and the receiving oscillator 4 are brought into contact with each other at an interval of m, and the longitudinal wave of the ultrasonic pulse is transmitted from the transmitting unit 5, received by the receiving unit 6, and the sample is transmitted from the transmitting oscillator. The time it takes for the wave to pass through the receiving oscillator is measured and converted to the propagation speed. For the sample, the propagation speed in both the MD and CD directions is measured, and the propagation speed ratio is determined. In the figure, reference numeral 7 denotes an arithmetic element, and 8 denotes a display element.

Longitudinal wave propagation velocity ratio of ultrasonic pulse and temperature 25
° C humidity 85% R. H. As shown in the relationship of the Clark stiffness in the horizontal direction under the environment (FIG. 2), the stiffness in the horizontal direction hardly changes when the longitudinal wave propagation velocity ratio of the ultrasonic pulse is in the range of 1.10 to 1.40. If it exceeds 1.40, the stiffness in the lateral direction starts to greatly decrease. Therefore, it was confirmed that the ratio of the longitudinal propagation velocity of the ultrasonic pulse needs to be 1.40 or less in order to keep the lateral stiffness in an appropriate range. Although the vertical stiffness is slightly reduced by this, it has already been confirmed that the strength is sufficient for the electrophotographic transfer paper (the broken line in the figure is the horizontal direction, and the solid line is the vertical clerk stiffness). . Here, the temperature 25 is adjusted by adjusting the ratio of the longitudinal propagation speed of the ultrasonic pulse to be small.
° C humidity 85% R. H. The stiffness in the transverse direction under the environment can be increased because the orientation of the fibers is less directional, and the difference in elasticity between the fiber length direction and the perpendicular direction appears as the difference in stiffness of the entire sheet Because there is no. Also,
As a method for reducing the longitudinal wave velocity ratio of the ultrasonic pulse, it is effective to appropriately adjust the JET / WIRE ratio (raw material ejection speed / paper machine wire speed ratio). A method of reducing the tension in the machine direction of the paper and the tension in the machine direction when the dryer is dried can be adopted.

Ash content and temperature 25 ° C Humidity 85% H. Regarding the relationship of stiffness under the environment, if the ash content exceeds 5%, the stiffness is reduced under the normal environment (temperature 20 ° C, humidity 65% RH).
The temperature was 25 ° C and the humidity was 85% R. H. It was confirmed that the ash content needs to be 5% or less in order to keep the stiffness in an appropriate range under the environment. However, in the transfer paper using the conventional bleached virgin pulp, when the ash content is reduced, the opacity is reduced and troubles such as show-through occur. Due to the characteristics of recycled pulp, the density of recycled pulp tends to decrease slightly, and the inclusion of mechanical pulp does not reduce opacity, so there is no trouble and the ash content can be reduced to 5% or less. Become.

Further, the paper thickness and the temperature 2 for a paper having a standard basis weight of 64 to 70 g / m ² as an electrophotographic transfer paper are used.
5 ° C., 85% R.H. H. The relationship of stiffness under the environment is
Temperature 25 ° C Humidity 85% R. H. It was discovered that when the paper thickness under humidity control for 2 hours or more under the environment became 97 μm or less, the stiffness in the horizontal direction began to decrease sharply, and in order to keep the stiffness in an appropriate range under the above environment, it was 98 μm or more. You need to make sure. Here, an increase in the paper thickness causes a problem in the image quality due to a decrease in the sorter storage capacity after copying and a decrease in the smoothness, so it is important to maintain the range in which the suitability of the electrophotographic paper is not lost. 2
5 ° C., 85% R.H. H. It is necessary that the paper thickness when the humidity is adjusted below 2 hours or more is 110 μm or less.

[0012] Here, the horizontal clerk stiffness can be improved by using the horizontal paper as the transfer paper for electrophotography. However, along with this, the vertical stiffness is insufficient and the handling property is poor and the heat roll is poor. Various problems, such as wrinkling at the time of fixing the system, occur. Therefore, it is preferable to use vertical grain paper as the electrophotographic transfer paper.

Waste paper pulp used in the present invention is used for cutting, waste paper, etc. generated in bookbinding, printing factories, cutting shops, and the like.
The lithographic process is performed on waste paper pulp, fine paper, high quality coated paper, medium quality paper, medium quality coated paper, blank paper, etc. Recycled paper, intaglio printing, intaglio printing, electrophotographic method, thermal method, thermal transfer method, pressure-sensitive recording method, ink jet recording method, waste paper printed with carbon paper, water-based, oil-based ink, waste paper written with pencil, etc. Can be used, such as pulp deinked after disintegration (hereinafter abbreviated as DIP), but in the present invention, in order to achieve the mechanical pulp content as described above, the blending ratio is controlled by selection and combination.
In addition to the above-mentioned waste paper, virgin chemical pulp (hardwood bleached kraft pulp, softwood bleached kraft pulp, hardwood unbleached kraft pulp, hardwood bleached sulphite pulp, softwood bleached sulphite pulp, hardwood bleached sulphite pulp, Pulp made by chemically treating wood and other fiber materials, such as softwood unbleached sulfite pulp)
After mechanically pulping ground wood, chips or ground pulp, or chemicals into wood or chips, then mechanically pulping the chemical ground pulp, chemimechanical pulp, and chips into a slightly softened pulp. After that, a virgin pulp such as a semi-chemical pulp pulped with a refiner may be contained. However, it is preferable to contain virgin chemical pulp other than the above-mentioned used paper.

Fillers that can be used in the recycled paper for transfer of the present invention include heavy calcium carbonate, light calcium carbonate, calcium carbonate such as chalk, kaolin, calcined clay, pyrophillite, sericite, and talc. Although inorganic fillers such as acids and organic pigments such as urea resin can be used, it is necessary to add them in consideration of the ash contained in the raw material of waste paper. When it is added, it is preferable to add calcium carbonate from the viewpoint of maintaining image quality in an electrophotographic system.

As the internal sizing agent used in the present invention, sizing agents such as a rosin sizing agent, a synthetic sizing agent, a petroleum resin sizing agent, a neutral sizing agent and the like can be used. An appropriate sizing agent and a fixing agent for fibers are used in combination. Desirably, a neutral sizing agent, particularly an alkenyl succinic anhydride-based sizing agent, is used from the viewpoints of the running property in an electrophotographic copying machine, a printer, and the like and the paper preservability after copying. Further, preparation of raw materials and control of production conditions are performed to impart electrophotographic aptitude such as copy aptitude and runnability.

In order to prevent image disturbance and maintain an appropriate copy image density, a conductive agent such as sodium chloride, potassium chloride, a styrene-maleic acid copolymer, or a quaternary ammonium salt is applied to the surface of a paper machine using a size press. After application, the surface electric resistance (according to JIS K 6911) of the transfer paper is set to 10 ⁹ to 10 ¹¹ Ω (temperature 20 ° C., humidity 65%).
R. H. ). Further, in order to improve the sharpness of the copy image portion, the surface unevenness is reduced by a calendering process or the like so that the smoothness (JIS P 8119) of the transfer paper is 1
The time is set to 0 seconds or more, preferably 20 seconds or more. The product moisture immediately after opening is adjusted by a paper machine dryer, a calendering process, a cutting process, or the like so that the product moisture becomes 4.0 to 6.5% of an appropriate moisture in order to suppress waving and curling after copying. . In addition, in order to prevent moisture absorption and desorption during storage, it is packaged with moisture-proof wrapping paper such as polyethylene laminated paper or a polypropylene film.

[0017]

EXAMPLES The present invention will be described in more detail with reference to the following examples, which, of course, are not intended to limit the scope of the present invention. Example 1 As shown in Example 1 in Table 1 below, a mechanical pulp (MP) was blended with 55% of the MP content in used newspaper DIP, that is, 55% in total, and used pulp other than MP was used newspaper DIP.
The chemical pulp (CP) content of 15% and the hardwood bleached kraft pulp (L-BKP) were blended at 30%, and the waste paper blending ratio was 70%. Longitudinal wave propagation velocity ratio of ultrasonic pulse (T /
Y ratio) was measured using a measuring instrument (SST-210 (SONIC S
HEET TESTER-210) manufactured by Nomura Shoji Co., Ltd.), the production conditions are determined so that the ash content is 1.15, the ash content is 0.8%, and the paper thickness is 98 μm. Using this stock, the paper is machined in a fourdrinier paper machine, and further subjected to size press treatment to impart indirect electrophotographic suitability to starch 1 g / m ² and sodium chloride 0.2 g.
/ M ² to obtain a recycled paper for transfer of the present invention. The copy suitability of this transfer paper in a high-humidity environment was confirmed as follows. This transfer paper (A4 size)
Prepare 00 sheets and stack them in the tray as they are 2
5 ° C 85% R. H. After leaving it on the desk overnight (16 hours) in the environment described above, a copier (FX5075, manufactured by Fuji Xerox Co., Ltd.) collected one-sided copies and two-sided copies 250 sheets each in a discharge tray and 250 sheets in a sorter, The occurred paper jam rate and other troubles were confirmed. Table 1 shows the results. As is evident from Table 1, the T / Y ratio was 1.15, the ash content was 0.8%, and the paper thickness was 98 μm. H. Lateral stiffness is 29.9cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 2 As shown in Example 2 in Table 1 below, as an MP, an MP content in used newspaper DIP was 20%, and ground pulp (GP) 5 was used.
%, Thermomechanical pulp (TMP) 10% 35 in total
%, As a pulp other than MP, 5% of CP in newspaper DIP, 45% of Kamishira Pulp, 15% of L.BKP
The blending ratio was 70%. T / Y ratio 1.20
, 2.8% ash, paper thickness 101 µm, and the internal size as shown in Table 1 was blended. The paper material was used to make a fourdrinier paper machine, In order to impart electrophotographic aptitude, starch was applied by a size press treatment so as to be 1 g / m ² and 0.2 g / m ² of sodium chloride to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1.
Table 1 shows the results. As is clear from Table 1, T
/ Y ratio of 1.20, ash content of 2.8%, paper thickness of 101 μm, 25% C 85% R. H. Lateral stiffness is 30.5 cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 3 As shown in Example 3 in Table 1 below, 50% of MP in waste newspaper DIP, and chemical ground pulp (CG) were used as MP.
P) 30%, a total of 80% was blended, and a pulp other than MP was blended with 20% of CP in waste newspaper DIP, and the waste paper blending ratio was 70%. The production conditions were determined so that the T / Y ratio was 1.40, the ash content was 4.9%, and the paper thickness was 110 μm.
An internal size as shown in the table was blended, and the paper material was used to make a paper with a fourdrinier paper machine. Further, in order to impart indirect electrophotographic aptitude, the starch was subjected to size press treatment at 1 g / m ² , Coating was performed so as to be 0.2 g / m ² to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 1 shows the results.
As is apparent from Table 1, the T / Y ratio is 1.40 and the ash content is 4.
Due to the effect of 9% and paper thickness of 110 μm, 25 ° C
85% R. H. Stiffness in an environment of 27.4 cm
^The ratio was 3/100, and recycled paper for transfer with less paper jam was obtained even when running in a high humidity environment.

Example 4 As shown in Example 4 of Table 1, used newspaper was DI as MP.
40% MP in P, 20% CGP, 60% in total,
CP content in used newspaper DIP as pulp other than MP 10
%, 30% Kamishiro used pulp, 80% used paper
And T / Y ratio 1.21, ash content 4.2%, paper thickness 98
μm, the production conditions are determined, and the internal size as shown in Table 1 is blended. The paper stock is used to make a paper using a fourdrinier paper machine. The starch was applied by press treatment so as to have a starch content of 1 g / m ² and sodium chloride of 0.2 g / m ² to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 1 shows the results. As is clear from Table 1, the T / Y ratio was 1.21, the ash content was 4.2%,
Due to the effect of paper thickness of 98 μm, 25% 85%
R. H. Lateral stiffness in the environment of 29.2 cm ^3/1
In other words, the recycled paper for transfer with less paper jam was obtained even when running in a high humidity environment.

Example 5 As shown in Example 5 in Table 2, the waste paper DI was used as MP.
50% of MP in P is mixed with 50% in total, and as pulp other than MP, 20% of CP in waste paper DIP, 10% of recycled paper pulp DIP of high quality electrophotographic transfer paper, L-BKP20
% And the used paper mixing ratio was 80%. T / Y ratio 1.1
2. The production conditions were determined so that the ash content was 5.0% and the paper thickness was 101 μm, and the internal addition size as shown in Table 2 was blended, and the resulting stock was used to make a fourdrinier paper machine. Starch was applied to give 1 g / m ² and 0.2 g / m ² of sodium chloride by size press treatment in order to impart indirect electrophotographic suitability, thereby obtaining a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1.
Table 2 shows the results. As is clear from Table 2, T
/ Y ratio of 1.12, ash content of 5.0%, and paper thickness of 101 μm. H. Lateral stiffness is 29.9cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 6 As shown in Example 6 in Table 2 below, MP was mixed with 40% of MP in used newspaper DIP and 5% of TMP in a total of 45%, and as a pulp other than MP, CP in used newspaper DIP was used. 15%, used white paper pulp 25% and L-BKP 15% were mixed, and the used paper mixing ratio was 80%. T / Y ratio of 1.39,
The production conditions were determined so that the ash content was 1.1% and the paper thickness was 105 μm, and the internal addition size as shown in Table 2 was blended. The paper material was used to make paper using a fourdrinier paper machine. a size press to impart photo aptitude, starch 1 g / m ^2, was coated such that the sodium chloride 0.2 g / m ^2, to obtain a transfer recycled paper of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 2 shows the results. As is clear from Table 2, the T / Y ratio was 1.
39, an ash content of 1.1%, and a paper thickness of 105 μm. H. Lateral stiffness is 26.9cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 7 As shown in Example 7 in Table 2, the waste paper DI was used as MP.
30% of MP in P, 20% of GP, 50% in total, M
CP content in used newspaper DIP as pulp other than P 10
%, Imitation waste paper DIP 40% blended, waste paper blending ratio is 80%
And T / Y ratio 1.32, ash content 3.0%, paper thickness 11
The production conditions are determined so as to be 0 μm, and the internal size as shown in Table 2 is blended. The paper stock is used to form a paper using a fourdrinier paper machine. The starch was applied by press treatment so as to have a starch content of 1 g / m ² and sodium chloride of 0.2 g / m ² to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 2 shows the results. As is clear from Table 2, the T / Y ratio was 1.32, and the ash content was 3.0.
%, Paper thickness of 110 μm, 25 ° C8
5% R. H. Lateral stiffness in an environment of 28.0 cm ³
/ 100, and a recycled paper for transfer with less paper jam was obtained even when running in a high humidity environment.

Example 8 As shown in Example 8 in Table 2 below, MP was mixed with 25% of MP in newspaper DIP and 5% of TMP in a total of 30% as MP, and CP in newspaper DIP was used as pulp other than MP. 10%, 55% of imitation waste paper DIP and 5% of L-BKP were blended, and the waste paper blending ratio was 90%. T / Y ratio of 1.35,
The production conditions were determined so that the ash content was 5.0% and the paper thickness was 98 μm, and the internal size as shown in Table 1 was blended. The paper material was used to make a fourdrinier paper machine. a size press to impart photo aptitude, starch 1 g / m ^2, was coated such that the sodium chloride 0.2 g / m ^2, to obtain a transfer recycled paper of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 2 shows the results. As is apparent from Table 2, the T / Y ratio is 1.3.
5, ash content 5.0%, paper thickness 98 μm, and the effect of 25 ° C. 85% R.C. H. Lateral stiffness is 26.9cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 9 As shown in Example 9 in Table 3, used newspaper was DI as MP.
30% of MP in P, 10% of GP, 40% in total, M
CP content in used newspaper DIP as pulp other than P 10
%, High-quality electrophotographic transfer paper waste paper pulp DIP 50% was blended, and the waste paper blending ratio was 90%. T / Y ratio 1.40
The ash content was 3.8% and the paper thickness was 101 μm. The production conditions were determined, and the internal addition size as shown in Table 3 was blended. In order to impart electrophotographic aptitude, starch was applied by a size press treatment so as to be 1 g / m ² and 0.2 g / m ² of sodium chloride to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1.
Table 3 shows the results. As is clear from Table 3, T
/ Y ratio of 1.40, ash content of 3.8%, paper thickness of 101 μm, 25% C 85% R. H. Lateral stiffness is 26.3cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 10 As shown in Example 10 in Table 3 below, 60% of MP content in used newspaper DIP was added as MP, and 20% of CP content in used newspaper DIP was used as pulp other than MP. The used white paper pulp 10% and L-BKP 10% were mixed, and the used paper mixing ratio was 90%. T / Y ratio 1.10, ash content 3.1
%, Paper thickness of 105 μm, the internal size as shown in Table 3 was blended, and the stock was used to make a Fourdrinier paper machine to further provide indirect electrophotographic suitability. 1g / m starch by size press
² , Coating so that the concentration of sodium chloride is 0.2 g / m ² ,
The transfer recycled paper of the present invention was obtained. This transfer sheet was evaluated in the same manner as in Example 1. Table 3 shows the results. As is clear from Table 3, the effect of setting the T / Y ratio to 1.10, the ash content 3.1%, and the paper thickness 105 μm resulted in 2
5 ° C 85% R. H. The lateral stiffness in the environment is 28.
0 cm ^3/100, and the transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 11 As shown in Example 11 of Table 3, used newspaper D was used as MP.
20% of MP content in IP and 10% of RGP are mixed in total 30%. As pulp other than MP, 5% of CP in newspaper DIP and 65% of Kamishiro old paper pulp are mixed.
%. T / Y ratio 1.26, ash content 0.9%, paper thickness 1
The production conditions are determined so as to be 10 μm, and the internal sizes as shown in Table 3 are blended. The paper stock is used to form a paper using a fourdrinier paper machine. The starch was applied by press treatment so as to have a starch content of 1 g / m ² and sodium chloride of 0.2 g / m ² to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 3 shows the results. Third
As is clear from the table, the T / Y ratio was 1.26 and the ash content was 0.9.
%, Paper thickness of 110 μm, 25 ° C8
5% R. H. Lateral stiffness in an environment of 28.0 cm ³
/ 100, and a recycled paper for transfer with less paper jam was obtained even when running in a high humidity environment.

Example 12 As shown in Example 12 in Table 3 below, 75% of the MP content in used newspaper DIP was mixed as MP in a total of 75%, and 25% of the CP content in used newspaper DIP was mixed as pulp other than MP. The used paper mixing ratio was 100%. T / Y ratio 1.39
, 3.2% ash content, 98 μm paper thickness, and set the internal conditions as shown in Table 3.
And papermaking in a Fourdrinier paper machine using this paper stock, with a size press in order to further impart adaptability for indirect electrophotography, coated so as starch 1 g / m ^2, and sodium chloride 0.2 g / m ² Thus, a recycled paper for transfer of the present invention was obtained. This transfer sheet was evaluated in the same manner as in Example 1. Table 3 shows the results. As evident from Table 3. The T / Y ratio was 1.39, the ash content was 3.2%, and the paper thickness was 98 μm. H. Lateral stiffness is 25.2cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 13 As shown in Example 13 in Table 4 below, 40% of the MP content in the used newspaper DIP was mixed as MP, and 40% of the CP in the used newspaper DIP was used as pulp other than MP. 45% of imitation waste paper DIP was blended, and the blending ratio of waste paper was 100%. T / Y ratio 1.28, ash content 1.1%, paper thickness 101μ
m, the production conditions are determined, and the internal addition size as shown in Table 4 is blended. The paper stock is used for papermaking with a fourdrinier paper machine, and the size for imparting indirect electrophotographic aptitude. The starch was applied by press treatment so as to have a starch content of 1 g / m ² and sodium chloride of 0.2 g / m ² to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 4 shows the results. As evident from Table 4. T / Y ratio 1.28, ash content 1.1%,
Due to the effect of paper thickness of 101 μm, 25% 85%
R. H. Lateral stiffness in the environment of 26.9cm ^3/1
In other words, the recycled paper for transfer with less paper jam was obtained even when running in a high humidity environment.

Example 14 As shown in Example 14 in Table 4 below, 30% of the MP content in the used newspaper DIP was mixed as MP, and 30% of the pulp other than MP was used. 30% of imitation waste paper DIP and 30% of Kamishira waste paper pulp were blended, and the blending ratio of waste paper was 100%. The production conditions were determined so that the T / Y ratio was 1.21, the ash content was 4.9%, and the paper thickness was 105 μm, and the internal sizes shown in Table 4 were blended. and papermaking in the machine, further a size press to impart adaptability for indirect electrophotography, coated so as starch 1 g / m ^2, and sodium chloride 0.2 g / m ^2, transfer recycled paper of the present invention I got This transfer sheet was evaluated in the same manner as in Example 1. Table 4 shows the results. As evident from Table 4. T / Y ratio
21, ash content 4.9%, paper thickness 105 μm, 25 ° C 85% R. H. Lateral stiffness is 27.4cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Example 15 As shown in Example 15 in Table 4, the waste paper D was used as the MP.
50% of MP content in IP, 50% in total, mixed as a pulp other than MP, 20% of CP content in newspaper DIP, 20% of Kamishira waste paper pulp, transfer paper waste paper pulp DI for high quality electrophotography
P10% was blended, and the waste paper blending ratio was 100%. T / Y
The production conditions were determined so that the ratio was 1.10, the ash content was 4.1%, and the paper thickness was 110 μm. The internal addition size as shown in Table 4 was blended, and papermaking was performed using the stock with a fourdrinier paper machine. Further, starch was added in an amount of 1 g / m ² and sodium chloride 0.2 g by a size press treatment to impart indirect electrophotographic suitability.
/ M ² to obtain a recycled paper for transfer of the present invention. This transfer sheet was evaluated in the same manner as in Example 1. Table 4 shows the results. As evident from Table 4. T / Y ratio 1.10, ash content 4.1%, paper thickness 110
μm, at 25 ° C., 85% RH. H. Lateral stiffness is 27.4cm ^3/100 next in the environment, transfer recycled paper less paper jam even in the running under a high humidity environment were obtained.

Comparative Examples 1 to 5 For comparison with Examples 1 to 3, papermaking was carried out at a used paper mixing ratio of 70% or less and in the formulation as shown in Table 5 or Table 6. For the obtained transfer paper, the occurrence rate of paper jam was confirmed by the same experimental method as in Example 1. The results are described in the following 5th and 6th
It is shown in the table.

Comparative Example 6 For comparison with Examples 4 to 7, papermaking was carried out according to the formulation shown in Table 6 at a compounding ratio of MP of 30% or more and a waste paper mixing ratio of 80%. For the obtained transfer paper, the occurrence rate of paper jam was confirmed by the same experimental method as in Example 1. The results are shown in Table 6 below.

Comparative Example 7 For comparison with Examples 8 to 11, the mixing ratio of MP was 30%.
Papermaking was carried out with the formulation shown in Table 7 at a waste paper mixing ratio of 90%. For the obtained transfer paper, the occurrence rate of paper jam was confirmed by the same experimental method as in Example 1. The results are shown in Table 7 below.

Comparative Examples 8-9 For comparison with Examples 11-15, the mixing ratio of MP was 30
The paper was made according to the formulation shown in Table 7 with the percentage of used paper being 100% or more and 100%. For the obtained transfer paper, the occurrence rate of paper jam was confirmed by the same experimental method as in Example 1.
The results are shown in Table 7 below.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Table 5]

[0041]

[Table 6]

[0042]

[Table 7]

The meanings of the abbreviations in each table are as follows. PPCDIP; high quality electrophotographic paper waste paper DIP, imitation DIP; imitation waste paper DIP, printing DIP; high quality printing waste paper D
IP, newspaper DIP; used newspaper DIP, used white paper DIP;
Waste paper pulp, ASA; alkenyl succinic anhydride, A
KD: alkyl ketene dimer. The propagation velocity ratio is a longitudinal propagation velocity ratio of an ultrasonic pulse (measured by a Sonnik sheet tester “SST-210” manufactured by Nomura Corporation). The lateral stiffness was 25 ° C., 85% RR. H. It was measured after conditioning the environment. Further, the paper jam rate is determined by the copying machine (FX50).
75, manufactured by Fuji Xerox Co., Ltd.). The meanings of the symbols in the table are shown below. ◎: no occurrence, ；: occurrence rate of less than 2%, Δ: occurrence rate of 2% or more
4% x; occurrence rate 5% to 10%, xx; occurrence rate exceeding 10. In the measurement of the paper jam rate in Comparative Example 8, in addition to the paper jam, poor toner fixability occurred and a sorter was used. Occasionally, a trouble of improper storage of the specified number occurred.

[0044]

The transfer paper for electrophotography of the present invention contains 70% or more of waste paper pulp in the whole pulp and has a temperature of 25% even though the ratio of mechanical pulp is 30% or more.
℃ humidity 85% R. H. Clark stiffness under environment 25c
98μm~ the thickness of the paper with at m ^3/100 or more
Since it is in the range of 110 μm , the present transfer paper can be used in the same manner as a conventional electrophotographic transfer paper made of bleached virgin pulp even when used in an indirect electrophotographic copying machine. In particular, troubles such as paper jam in a transfer paper containing waste paper pulp in a high humidity environment are improved.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE FIGURES FIG. H. The relationship between the lateral clarity stiffness in the environment and the content ratio of waste paper is shown. In addition, the newspaper pulp DIP, the printing waste paper DIP, L-BKP, and GP were combined and blended so that the mechanical pulp ratio in the whole pulp was 50%. At this time, the basis weight is 67 g / m ² and the paper thickness is 96 μm.
m, ash content: 3.0%, longitudinal wave propagation velocity ratio: 1.55.

FIG. 2 Longitudinal wave propagation velocity ratio of ultrasonic pulse and temperature of 25 ° C.
Humidity 85% R. H. Shows the relationship of Clark stiffness below. In addition, used paper DIP, L was used so that the percentage of used paper in all pulp was 90% and the ratio of mechanical pulp was 40%.
-BKP was combined and blended. At this time, the basis weight is 64 g /
m ² , paper thickness 102 μm, ash content 6.5%.

FIG. 3 shows a block diagram of a method for measuring a longitudinal wave propagation velocity of an ultrasonic pulse.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 bubble-containing rubber plate 2 test sample 3 transmitting oscillator 4 receiving oscillator 5 transmitting unit 6 receiving unit 7 arithmetic element 8 display element

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-217862 (JP, A) JP-A-4-11098 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D21H 11/00-11/22 D21H 27/00

Claims (3)

(57) [Claims] 1. A contained 70% of the used paper pulp in the total pulp is the proportion of mechanical pulp is 30% or more,
Temperature 25 ° C Humidity 85% R. H. In an environment with a transverse Clark stiffness of the paper is 25 cm ^3/100 or more
A transfer paper for electrophotography , wherein the thickness of the paper is in the range of 98 μm to 110 μm . 2. A longitudinal wave propagation velocity ratio of an ultrasonic pulse is 1.4.
2. The transfer paper for electrophotography according to claim 1, wherein the value is 0 or less. 3. The electrophotographic transfer paper according to claim 1, wherein the ash content is 5% or less.