JP3003372B2 - 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 sheets fed from the lateral direction has increased, and the paper has been conveyed in a complicated machine, and the conditions have become increasingly severe for the paper. In the horizontal direction, the long side corresponds to the paper advancing direction (vertical direction of the paper) in papermaking at the time of manufacturing, and means the horizontal direction of the paper, which is generally called the vertical line, that is, the direction parallel to the short side. 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. By the way, an electrophotographic paper containing waste paper is disclosed in Japanese Patent Publication No. 63-6867, but means for solving the problems such as the running property of the paper absorbed in a high humidity environment as described above are presented. Absent. Also, in order to solve the problem caused by curling after copying, JP-A-3-236062 discloses a difference in expansion and contraction ratio of the front and back sides of the paper, and JP-A-3-243953 discloses means for specifying a residual curvature. No means for solving problems such as the running properties of paper that has absorbed moisture under the environment is disclosed.

[0004]

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 sheet mainly composed of a conventional bleached virgin pulp, which includes electrophotographic aptitude including troubles such as wrinkling of a copy and paper jam in a copy operation under a high humidity environment (hereinafter, referred to as a Providing transfer paper for electrophotography (hereinafter referred to as recycled paper for transfer) containing 70% or more of waste paper pulp in all pulp and having a mechanical pulp ratio of 30% or more. Is to do.

[0005]

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 to 80% , and the paper expands and contracts in the horizontal direction. The rate is 0.60% or less. Further, the longitudinal wave propagation velocity ratio (T / Y
Ratio) is 1.40 or less, and the freeness of the pulp suspension from which the recycled paper for transfer is disintegrated is 200 ml (CSF) or more.

The present inventors have observed the occurrence of wrinkles in the above-mentioned copy. When copying in a high-humidity environment, if the opened sheets are left stacked and stacked, except for some of the upper sheets, the heat roll type It was confirmed that wrinkles occurred at the trailing edge of the paper in the image fixing section of No. 1. Further examination of the wrinkling condition at the fixing section revealed that the paper with wrinkles had a moisture content of 2-3% higher in the peripheral part than in the central part, so the dimensions of the peripheral part were longer than those in the central part, It was confirmed that waviness was generated, and that when this waviness was large, wrinkles were generated. In particular, recycled paper containing waste newspaper is easy to absorb moisture due to the high mechanical pulp ratio in the total pulp, and when copying in a high humidity environment due to its large expansion and contraction, the moisture absorption in the peripheral area becomes faster and the ripples are generated. It was getting bigger.

Further, the present inventors have energetically investigated means for reducing the waving of the paper, and as a result, by reducing the expansion / contraction ratio of the paper in the horizontal direction to 0.60% or less, the peripheral portion of the paper in a high-humidity environment is reduced. Was found to be less undulating, and the occurrence of wrinkles was sharply reduced (see FIG. 1). Furthermore, the present inventors have worked diligently to study a technique for reducing the horizontal expansion and contraction rate to 0.60% or less while maintaining electrophotographic aptitude on recycled paper containing used newspaper, and as a result, the T / Y ratio was 1.40 or less, and the transfer was performed. It was confirmed that the above conditions were satisfied by adjusting the freeness of the pulp suspension obtained by disintegrating the recycled paper for paper to 200 ml or more (measured according to the Canadian standard form described in JIS-P-8121). It was completed. Incidentally, the above-mentioned Japanese Patent Application Laid-Open No. Hei 3-236062 discloses that the curl is improved by reducing the difference between the front and back within the conventionally known range of the fiber orientation aspect ratio, and adjusting the difference between the front and back of the expansion ratio of the paper. ing. However, the problem of the present invention, namely, the generation of wrinkles in the fixing section of a copying machine in a high-humidity environment cannot be solved only by adjusting the difference between the front and back sides of the expansion ratio.
The present invention adjusts the fiber orientation aspect ratio of all layers of paper (longitudinal wave propagation velocity ratio) to a range that has been said to cause a problem in the past, and that a recycled paper having stable quality even in a high humidity environment is possible. It is a headline.

The details of the present invention are described below. The “paper expansion / contraction rate” in the present invention refers to a temperature of 20 ° C., a humidity of 65% RH → 25
% RH → 65% RH → 90% RH ”means the dimensional change rate when the moisture absorption / desorption process is repeated for three cycles and the final 65% RH → 25% RH is changed. The “longitudinal wave propagation velocity ratio (T / Y ratio) of the pulse” means a value represented by the following equation. Longitudinal wave propagation velocity ratio of ultrasonic pulse = Ultrasonic propagation velocity in machine direction (MD) / Ultrasonic propagation velocity in cross direction (CD) `` 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, the sample 2 is placed on a 10 mm-thick bubbled rubber plate 1, and the transmitting oscillator 3 and the receiving oscillator 4 are brought into contact with each other at an interval of 150 mm to transmit a longitudinal wave of an ultrasonic pulse. The wave is sent out from the wave unit 5, received by the wave receiving unit 6, and the time required for the sample to pass through the transmitting oscillator and be received by the receiving oscillator is measured and converted into a propagation velocity. For each sample, the propagation speed in both the MD and CD directions is measured, and the propagation speed ratio is determined. In the figure, 7 is an arithmetic element, and 8 is a display element.
The freeness of the pulp suspension obtained by disintegrating the recycled paper for transfer in the present invention is JIS-P-8121, Canadian standard type (CSF)
Measure the recycled paper for transfer directly as a sample according to.

As shown in the relationship between the transverse expansion and contraction rate of paper, the blending ratio of waste paper and the T / Y ratio (FIG. 2), when the T / Y ratio is in the range of 1.00 to 1.40, the horizontal expansion and contraction rate does not change much. , More than 1.40, it increases sharply, especially when the content ratio of waste paper pulp exceeds 70%. Therefore, the T / Y ratio needs to be 1.40 or less in order to keep the expansion ratio in an appropriate range.
As a method of reducing the T / Y ratio, it is effective to adjust the JET / WIRE ratio (raw material ejection speed / paper machine wire speed ratio). It can also be controlled by reducing the tension of the dryer and the tension in the machine direction during drying of the dryer. In addition, as shown in the relationship between the transverse expansion and contraction ratio of paper, the paper disintegration pulp freeness, and the T / Y ratio (FIG. 3), the recycled paper of the present invention is a filter for a pulp suspension obtained by disintegrating paper. When the water content is lower than 200 ml, the expansion / contraction ratio in the horizontal direction becomes difficult to control even by the T / Y ratio. for that reason,
In order to keep the expansion ratio within an appropriate range, the paper disintegration pulp freeness needs to be 200 ml or more.

Recovered 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. , The pulp deinked after disaggregation
(Hereinafter, abbreviated as DIP) can be used, but in the present invention, in order to achieve the conditions of the mechanical pulp content and the freeness as described above, the mixing ratio is controlled by selection and combination.

In the present invention, in addition to the used paper, virgin chemical pulp (hardwood bleached kraft pulp, softwood bleached kraft pulp, softwood unbleached kraft pulp, hardwood bleached sulfite pulp, softwood bleached sulphite pulp, hardwood bleached Unbleached sulfite pulp, pulp made by chemically treating wood and other fiber materials such as unbleached sulfite pulp, softwood, etc.), ground pulp obtained by mechanically pulping wood or chips, or chemicals onto wood or chips After infiltration, a mechanically pulped chemical ground pulp, a chemimechanical pulp, and, after digesting the chips to be slightly soft, may contain a virgin pulp such as a semi-chemical pulp pulped with a refiner. . However, it is preferable to contain virgin chemical pulp other than the above-mentioned used paper. In the present invention,
The pulp suspension has a freeness of 20 when disintegrated from recycled paper.
In order to adjust the volume to 0 ml or more, the selection of the used paper and the combination and blending of the virgin pulp, and the preparation of the beating degree in the preparation process are performed.

Fillers that can be used in the recycled paper for transfer of the present invention include calcium carbonate such as heavy calcium carbonate, light calcium carbonate, chalk, kaolin, and the like.
Inorganic fillers such as calcined clay, porphyrite, sericite, silicic acid such as talc, and organic pigments such as urea resin can be used, but the ash (JIS-P-812
It is necessary to add in consideration of 8). When added, calcium carbonate is preferably added from the viewpoint of maintaining image quality in an electrophotographic system, and the ash content is preferably 8% or less.

The internal sizing agent used in the present invention includes:
Sizing agents such as rosin-based sizing agents, synthetic sizing agents, petroleum resin-based sizing agents, and neutral sizing agents can be used.
An appropriate sizing agent such as cationized starch 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. In addition, copy suitability,
Preparation of raw materials to provide electrophotographic aptitude such as runnability,
Control of manufacturing conditions is performed.

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 coating, the transfer sheet has a surface electric resistance (JIS K 6911) of 10 ⁹ to 10 ¹¹ Ω (temperature: 20 ° C., humidity: 65% RH).
H. ). In addition, in order to improve the sharpness of the copy image portion, the smoothness (JIS P 8119) of the transfer paper is made 10 seconds or more, preferably 20 seconds or more by reducing the surface irregularities by a calendering process or the like. 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.

[0015]

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 32% of the MP content in used newspaper DIP, a total of 32%, and used pulp other than MP was used newspaper DIP.
8% of chemical pulp (CP) in the inside, 30% of DIP recycled paper for high quality electrophotography, bleached hardwood kraft pulp (L
BKP) was used in an amount of 30%, and the used paper mixing ratio was 70%. And the longitudinal wave propagation velocity ratio (T / Y ratio) of the ultrasonic pulse
To a measuring instrument (SST-210 (Sonic Sheath)
TESTER-210) Measured by Nomura Shoji Co., Ltd.) and determined the production conditions so that the ash content was 1.15 and the ash content was 0.9%. Paper with a fourdrinier paper machine, and further subjected to size press treatment to impart indirect electrophotographic aptitude to 1 g / m ^{2 of} starch.
Coating was performed so that the concentration of sodium chloride became 0.2 g / m ² , thereby obtaining recycled paper for transfer of the present invention. The disintegration pulp freeness of the recycled paper for transfer was 380 ml, and the expansion and contraction ratio in the horizontal direction of the paper was measured using an isopycnic expansion ratio meter.
46%. The suitability of the transfer paper for copying in a high-humidity environment was confirmed as follows. That is, this transfer paper is
° C 85% R.C. H. In an environment of 100
After standing on a desk for one hour, single-sided copy, single-sided multiplex copy, and double-sided copy were performed with a copying machine (FX5075, manufactured by Fuji Xerox Co., Ltd.), and the wrinkle occurrence rate and the paper jam rate were confirmed. Table 1 shows the results. As is clear from Table 1, T / Y
As a result of the ratio 1.14, the paper disintegration pulp freeness set to 380 ml, and the expansion and contraction ratio of the paper in the horizontal direction set to 0.46%, no wrinkles are generated even during running after high humidity control, and paper jams occur. A transfer paper without transfer was obtained.

Example 2 As shown in Example 2 in Table 1 below, as mechanical pulp (MP), 20% of MP in waste newspaper DIP and 15% of thermomechanical pulp (TMP) were blended in a total of 35%, except for MP. 5% of chemical pulp (CP) in newspaper DIP, 45% of Kamishira waste paper pulp, L.
BKP was blended at 15%, and the waste paper blending ratio was 70%. T
/ Y ratio of 1.23 and ash content of 4.8%, the production conditions are determined, the internal addition size as shown in Table 1 is blended, and the stock is used to make a fourdrinier paper machine. 1g of starch by size pressing to give indirect electrophotographic suitability
/ M ² and 0.2 g / m ^{2 of} sodium chloride to obtain a recycled paper for transfer of the present invention. The paper pulverization pulp freeness of this transfer paper was 320 ml, and the lateral expansion / contraction ratio of the paper was 0.50%. This transfer sheet was evaluated in the same manner as in Example 1. Table 1 shows the results. First
As is clear from the table, the T / Y ratio is 1.23, the paper disintegration pulp freeness is 320 ml, and the paper expansion / contraction ratio is 0.1 mm.
As an effect of 50%, recycled paper for transfer free of wrinkles and paper jams even after running after high humidity control was obtained.

Example 3 As shown in Example 3 in Table 1 below, as an MP, 50% of an MP content in used newspaper DIP, and a chemical ground pulp (CG)
P) 30%, a total of 80% was blended, and as a pulp other than MP, a chemical pulp (CP) content of 20% in newspaper waste paper DIP was blended, and the blending ratio of waste paper was 70%. T / Y ratio 1.18,
The production conditions are determined so as to give an ash content of 4.5%, the internal addition size as shown in Table 1 is blended, and the stock is used to make a fourdrinier paper machine to further provide indirect electrophotographic suitability. For this purpose, starch was applied by a size press treatment so as to be 1 g / m ² and sodium chloride 0.2 g / m ² to obtain a recycled paper for transfer of the present invention. The paper disintegration pulp freeness of this transfer paper was 200 ml, and the paper expansion and contraction rate was 0.59.
%Met. 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 1.14 and the paper disintegration pulp freeness was 20.
The effect of setting the paper expansion and contraction rate in the horizontal direction to 0.59% was 0 ml, and there was little generation of wrinkles and no paper jam even in running after high-humidity humidity control. .

Example 4 As shown in Example 4 in Table 1 below, MP was mixed with 40% of MP in used newspaper DIP and 20% of CGP in a total of 60%, and as pulp other than MP, CP in used newspaper DIP was used. 10%, used white paper pulp 20%, printed used paper DIP 10%
The blending ratio was 80%. T / Y ratio 1.1
2. The production conditions are determined so that the ash content becomes 3.9%, the internal addition size as shown in Table 1 is blended, and the paper material is used to make a fourdrinier paper machine. In order to apply the starch, starch was applied so as to be 1 g / m ² and 0.2 g / m ² of sodium chloride by a size press treatment to obtain a recycled paper for transfer of the present invention. The paper disintegration pulp freeness of this transfer paper was 265 ml, and the expansion and contraction rate of the paper in the horizontal direction was 0.1 mm.
55%. This transfer sheet was evaluated in the same manner as in Example 1. Table 1 shows the results. As is evident from Table 1, the T / Y ratio was 1.12 and the defiberized pulp freeness was 2
The effect of setting the paper expansion / contraction rate to 65 ml and the paper expansion / contraction ratio to 0.55% was that transfer paper with little wrinkling and no paper jam was obtained even after running after high humidity control. .

Example 5 As shown in Example 5 of Table 2, newspaper MP was used as MP.
56% of MP in P, 56% in total, and 14% of CP in newspaper DIP, 10% of DIP high quality electrophotographic transfer paper, and 20% of L · BKP as pulp other than MP. 80%. T / Y ratio 1.25,
The production conditions are determined so that the ash content is 5.0%, the internal addition size as shown in Table 2 is blended, and the paper stock is used to make a Fourdrinier paper machine to further impart indirect electrophotographic suitability. For this purpose, starch was applied by a size press treatment so as to be 1 g / m ² and sodium chloride 0.2 g / m ² to obtain a recycled paper for transfer of the present invention. This transfer paper has a paper disintegration pulp freeness of 280 ml and a paper expansion / contraction ratio of 0.56%.
Met. 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 1.25 and the paper disintegration pulp freeness was 280.
ml, and as a result of making the lateral expansion / contraction ratio of the paper 0.56%, a recycled paper for transfer with less wrinkles and no paper jam was obtained even after running after high humidity conditioning. .

Example 6 As shown in Example 6 in Table 2, the waste paper DI was used as MP.
24% of MP in P, 10% of TMP 34% in total,
CP content in used newspaper DIP as pulp other than MP 6
%, Kamishirako Pulp 50%, L ・ BKP10%,
The used paper mixing ratio was 80%. The production conditions were determined so that the T / Y ratio was 1.40 and the ash content was 1.9%. The internal addition size as shown in Table 1 was blended, and the resulting stock was used to make a fourdrinier paper machine. Further, 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 aptitude, thereby obtaining recycled paper for transfer of the present invention. The paper pulverization pulp freeness of this transfer paper was 335 ml, and the lateral expansion / contraction ratio of the paper was 0.55%. 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 is 1.40 and the paper disintegration pulp freeness is 335 m.
As an effect of setting the paper expansion / contraction ratio to 0.55%, the transfer recycle paper with less wrinkles and no paper jams even after running under high humidity was obtained. .

Example 7 As shown in Example 7 of Table 2, used newspaper was DI as MP.
32% of MP in P and 10% of ground pulp (GP) 42% in total, used as newspaper pulp other than MP
The CP content in P is 8%, the imitation waste paper DIP 30%, and the high quality electrophotographic transfer paper waste paper DIP 20% are blended.
0%. The production conditions were determined so that the T / Y ratio was 1.35 and the ash content was 4.0%, the internal addition size as shown in Table 1 was blended, and the resulting stock was used to make a fourdrinier paper machine. Further, 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 aptitude, thereby obtaining recycled paper for transfer of the present invention. The paper disintegration pulp freeness of this transfer paper is 310 ml,
The transverse expansion / contraction ratio of the paper was 0.54%. This transfer sheet was evaluated in the same manner as in Example 1. The result is
It is shown in the table. As is apparent from Table 2, the T / Y ratio is 1.3.
5. As the effect of setting the paper disintegration pulp freeness to 310 ml and the expansion and contraction ratio of the paper in the horizontal direction to 0.54%, wrinkles are less generated and paper jams are generated even in running after high humidity conditioning. No recycled paper for transfer was obtained.

Example 8 As shown in Example 8 in Table 3, used newspaper newspaper DI was used as MP.
40% of MP in P, 40% in total, and as pulp other than MP, 10% of CP in waste paper DIP, 40% of Kamishiro old paper pulp, 10% of L-BKP, and 90% of waste paper did. The production conditions were determined so that the T / Y ratio was 1.29 and the ash content was 2.0%, the internal addition sizes as shown in Table 3 were 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 / m ² by a size press treatment to impart indirect electrophotographic suitability.
Thus, a recycled paper for transfer of the present invention was obtained. The paper disintegration pulp freeness of this transfer paper is 300 ml,
The transverse expansion / contraction ratio of the paper was 0.54%. This transfer sheet was evaluated in the same manner as in Example 1. The result is the third
It is shown in the table. As is clear from Table 3, the T / Y ratio was 1.2.
9. As the effect of setting the paper disintegration pulp freeness to 300 ml and the expansion and contraction rate of the paper in the horizontal direction to 0.54%, wrinkles are less generated even during running after high humidity conditioning, and paper jams are generated. No recycled paper was obtained.

Example 9 As shown in Example 9 in Table 3 below, 24% of the MP content in used newspaper DIP was mixed as MP, and a total of 34% was mixed. As a pulp other than MP, the CP content in used newspaper DIP was 6%. A high quality electrophotographic transfer paper waste paper DIP 60% was blended, and the waste paper blending ratio was 90%. The production conditions were determined so that the T / Y ratio was 1.24 and the ash content was 3.8%, the internal addition size as shown in Table 3 was blended, and the resulting stock was used to make 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 and sodium chloride at 0.2 g / m ² .
It was coated so as to m ^2, and to obtain a transfer recycled paper of the present invention. The paper disintegration pulp freeness of this transfer paper is 325 ml.
The expansion and contraction ratio of the paper in the horizontal direction was 0.51%. 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 T / Y ratio was 1.24, the paper disintegration pulp freeness was 325 ml, and the expansion and contraction rate of the paper in the horizontal direction was 0.51%. Also in the running, the transfer recycled paper with less wrinkles and no paper jam was obtained.

Example 10 As shown in Example 10 of Table 3, used newspaper D was used as MP.
A total of 74% of the MP content in the IP and 74% of the CGP were blended. A pulp other than the MP was blended with 16% of the CP in the waste paper DIP and 10% of the high quality electrophotographic transfer paper waste paper DIP 10%. did. The production conditions were determined so that the T / Y ratio was 1.26 and the ash content was 2.9%, the internal addition size as shown in Table 3 was blended, and the resulting stock was used to make a fourdrinier paper machine. Further, 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 aptitude, thereby obtaining recycled paper for transfer of the present invention. The paper pulverization pulp freeness of this transfer paper was 210 ml, and the paper expansion / contraction ratio was 0.60%. 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 T / Y ratio is 1.26 and the paper disintegration pulp freeness is 210 m.
The effect of setting the lateral expansion / contraction ratio of the paper to 0.60% was that less wrinkles were generated and no paper jam occurred even after running under high humidity conditions. .

Example 11 As shown in Example 11 in Table 3 below, 56% of MP content in used newspaper DIP was mixed as MP, and a total of 56% was used as pulp, and 14% of CP in used newspaper DIP was used as pulp other than MP. In addition, 30% of used printing paper DIP was mixed, and the mixing ratio of used paper was 100%. The production conditions were determined so that the T / Y ratio was 1.23 and the ash content was 1.2%, the internal addition size as shown in Table 3 was blended, and the resulting stock was used to make a fourdrinier paper machine. Further, 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 aptitude, thereby obtaining recycled paper for transfer of the present invention. The paper disintegration pulp freeness of this transfer paper was 260 ml, and the lateral expansion / contraction ratio of the paper was 0.57%. 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 T / Y ratio was 1.23, the paper disintegration pulp freeness was set to 260 ml, and the expansion and contraction ratio of the paper in the horizontal direction was set to 0.57%. Also in the running, the transfer recycled paper with less wrinkles and no paper jam was obtained.

Example 12 As shown in Example 12 of Table 4, used newspaper D was used as MP.
56% of MP content in IP, 56% in total, blended as pulp other than MP, 14% of CP in waste paper DIP, 10% of high quality electrophotographic transfer paper DIP, 10% of imitation waste paper DIP2
0% was used, and the used paper mixing ratio was 100%. The production conditions were determined so that the T / Y ratio was 1.28 and the ash content was 3.0%.
An internal size as shown in Table 4 was blended, the paper stock was used to form a paper using a fourdrinier paper machine, and the starch was subjected to a size press treatment to impart 1 g /
m ² and 0.2 g / m ^{2 of} sodium chloride to obtain a recycled paper for transfer of the present invention. The paper pulverization pulp freeness of this transfer paper was 270 ml, and the paper expansion / contraction ratio was 0.58%. This transfer sheet was evaluated in the same manner as in Example 1. Table 4 shows the results. As is apparent from Table 4, the T / Y ratio was 1.28, the paper disintegration pulp freeness was 270 ml, and the paper expansion / contraction ratio was 0.5.
As an effect of 8%, even when driving after high humidity control,
Recycled paper for transfer with little wrinkling and no paper jam was obtained.

Example 13 As shown in Example 13 of Table 4, used MP was used newspaper D.
48% of MP content in IP, 48% in total, blended as pulp other than MP, 12% of CP in newspaper DIP, 20% of Kamishiro paper pulp, and 20% of printed DIP, and 100% of recycled paper did. T / Y ratio 1.32, ash 4.1
%, The internal size as shown in Table 4 is blended, the stock is used to make a Fourdrinier paper machine, and a size press is used to impart indirect electrophotographic aptitude. By the treatment, starch was coated so as to have a concentration 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. The disintegration pulp freeness of this transfer paper is 2
At 80 ml, the transverse expansion and contraction of the paper was 0.58%. This transfer sheet was evaluated in the same manner as in Example 1.
Table 4 shows the results. As is evident from Table 4,
T / Y ratio of 1.32, paper disintegration pulp freeness of 280 ml, and expansion and contraction rate of paper in the horizontal direction of 0.58%. Thus, recycled paper for transfer free of paper jam was obtained.

Example 14 As shown in Example 14 in Table 4, used newspaper D was used as MP.
30% of MP content in IP, 30% in total, as a pulp other than MP, 10% of CP in waste paper DIP, 40% imitation waste paper DIP, waste paper DIP2 of high quality electrophotographic transfer paper
0% was used, and the used paper mixing ratio was 100%. The production conditions were determined so that the T / Y ratio was 1.38 and the ash content was 5.0%.
An internal size as shown in Table 4 was blended, the paper stock was used to form a paper using a fourdrinier paper machine, and the starch was subjected to a size press treatment to impart 1 g /
m ² and 0.2 g / m ^{2 of} sodium chloride to obtain a recycled paper for transfer of the present invention. The paper pulverization pulp freeness of this transfer paper was 315 ml, and the lateral expansion / contraction ratio of the paper was 0.56%. This transfer sheet was evaluated in the same manner as in Example 1. Table 4 shows the results. As is clear from Table 4, the T / Y ratio was 1.38, the paper disintegration pulp freeness was 315 ml, and the paper expansion and contraction rate was 0.5.
As an effect of 6%, even when driving after high humidity control,
Recycled paper for transfer with little wrinkling and no paper jam was obtained.

Comparative Examples 1 to 3 For comparison with Examples 1 to 3, papermaking was carried out at a used paper mixing ratio of 70% or less according to the formulation shown in Table 5. For the obtained transfer paper, the wrinkle occurrence rate was determined by the same experimental method as in Example 1.
The paper jam rate was checked. The results are shown in Table 5 below.

COMPARATIVE EXAMPLE 4 For comparison with Examples 4 to 6, 80% or more of the compounding ratio of MP was 30% or more.
As shown in Table 5, the papermaking ratio was as follows. The wrinkle occurrence rate and the paper jam rate of the obtained transfer paper were confirmed by the same experimental method as in Example 1. The results are shown in Table 5 below.

Comparative Example 5 For comparison with Examples 7 to 10, 90%
The paper was made according to the formulation shown in Table 6 as a percentage of used paper in%. The wrinkle occurrence rate and the paper jam rate of the obtained transfer paper were confirmed by the same experimental method as in Example 1. The results are shown in Table 6 below.

Comparative Examples 6 and 7 For comparison with Examples 11 and 14, 1
Papermaking was performed according to the formulation shown in Table 6 with a waste paper mixing ratio of 00%. The wrinkle occurrence rate and the paper jam rate of the obtained transfer paper were confirmed by the same experimental method as in Example 1. The results are shown in Table 6 below.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

[Table 4]

[0037]

[Table 5]

[0038]

[Table 6]

The meanings of the abbreviations in each table are as follows. PPCDIP; Fine electrophotographic paper waste paper DIP, Imitation DIP; Imitation waste paper DIP, Printing DIP; Fine print waste paper DIP, Newspaper DIP; Newspaper waste DI
P, Kamishiro old paper; Kamishiro old paper pulp, ASA; Alkenyl succinic anhydride, AKD; Alkyl ketene dimer. The propagation speed ratio is a ratio of longitudinal wave propagation speed of an ultrasonic pulse (measured by Nomura Corporation's Songk Seat Tester “SST-210”). Also,
The results of the high-humidity conditioning run were as follows: 100 sheets were stacked in a paper wet condition of 25 ° C and 85% RH, left for 2 hours on a desk, set in a copier (FX5075, manufactured by Fuji Xerox Co., Ltd.) and run in the same environment. Was. The meanings of the symbols in the table are shown below. ◎; no occurrence, ○: less than 5%, △: 5% to 10%, ×: 10% to 50%, XX; more than 50%

[0040]

The recycled paper for transfer according to the present invention uses the specified wastepaper pulp in spite of the fact that the ratio of the mechanical pulp is 30 to 80% while the total pulp contains 70% or more of the wastepaper pulp. When the freeness of the pulp suspension obtained by disintegrating the recycled paper for transfer obtained above becomes 200 ml (CSF) or more, the rate of expansion and contraction of the paper in the horizontal direction becomes 0.60% or less, and this transfer paper is indirectly used. Even when used in an electrophotographic copying machine, it can be used in the same manner as conventional electrophotographic transfer paper made of bleached virgin pulp. In particular, troubles such as copy wrinkles and paper jams are improved in a high humidity environment as compared with conventional transfer paper containing waste paper pulp.

[Brief description of the drawings]

FIG. 1 shows a relationship between a copy wrinkle occurrence rate and a lateral expansion / contraction rate of paper.

FIG. 2 shows the relationship between the lateral expansion / contraction ratio of paper, the used paper mixing ratio, and the longitudinal wave propagation speed ratio. In addition, the paper disintegration pulp freeness is 240m.
1 so that the mechanical pulp ratio in the total pulp is 50%, and used newspaper DIP, used printed paper DIP, L.BK
P and TMP were combined and blended. At this time, basis weight 66g
/ M ² , paper thickness 105 μm, ash content 1.8%.

FIG. 3 shows the relationship between the transverse expansion / contraction ratio of paper, the paper disintegration pulp freeness, and the ratio of longitudinal wave propagation velocity. In order to obtain a specified freeness, used newspaper DIP and printed waste paper DIP were blended, and the ratio of used paper in the total pulp was 100%, and the ratio of mechanical pulp was 3
The composition was adjusted to be 0% or more. At this time, the basis weight 66 g /
m ² , paper thickness 108 μm, ash content 4.5%.

FIG. 4 shows a block diagram of a method for measuring a longitudinal wave propagation velocity of an ultrasonic pulse.

[Explanation of symbols]

 1 Rubber plate with bubbles 2 Test sample 3 Transmitter oscillator 4 Receiver oscillator 5 Transmitter 6 Receiver 7 Arithmetic element 8 Display element

Continuation of front page (56) References JP-A-4-36760 (JP, A) JP-A-4-11098 (JP, A) JP-A-2-251967 (JP, A) (58) Fields studied (Int .Cl. ⁷ , DB name) D21H 11/00-11/22 D21H 27/00

Claims (3)

(57) [Claims] (1) The total pulp contains at least 70% of waste paper pulp, the ratio of mechanical pulp is 30 to 80% , and the lateral expansion / contraction ratio of the paper is 0.60% or less. Electrophotographic transfer paper. 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 pulp suspension from which paper has been disintegrated has a freeness of 2
2. The electrophotographic transfer paper according to claim 1, wherein the transfer paper is at least 00 ml (CSF).