JP3136806B2 - 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 In recent years, global environmental problems have surfaced, and the importance of protecting forest resources has been recognized. As one of countermeasures, the reduction of the use of wood resources by using waste paper as a raw material for paper has become a serious issue. In particular, for printing and information paper, which currently uses little recycled paper, it is desired to increase the use of recycled paper made from recycled paper.

[0003] Recent changes in copying machines and printers have been remarkable, and various functions such as an increase in copy speed, downsizing, double-sided copy and multiple copy have been enriched, and they have become widespread to models having relatively low copy speed.
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. However, in indirect electrophotographic copying machines, etc.,
When using recycled paper for electrophotography that uses waste paper as a raw material, troubles such as a decrease in the density of the copied image and omission of the image occur frequently in the copying work in a high humidity environment, and the copying work in a low humidity environment. Immediately after use, it has become clear that image disturbance and running trouble frequently occur due to static electricity, and there is a great problem in practical use. by the way,
Electrophotographic paper containing waste paper is sold in Japanese Patent Publication No. 63-6867.
However, there is no suggestion for solving the above-mentioned problems such as a decrease in image quality in a high-humidity environment. Japanese Patent Application Laid-Open No. Sho 55-142799 discloses a means for specifying the product moisture in order to solve the problem caused by the curl after copying. However, in order to solve the problem such as a decrease in image quality in a high humidity environment. No means is provided.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has been made in order to provide a recycled paper having electrophotographic aptitude and containing waste paper. Accordingly, an object of the present invention is to provide a transfer paper for electrophotography using a conventional bleached virgin pulp as a main raw material, which is suitable for electrophotography including troubles such as a decrease in the density of a copied image and omission of an image in a copying operation under a high humidity environment. It is an object of the present invention to provide an electrophotographic transfer paper (hereinafter, referred to as transfer recycled paper) containing 70% or more of waste paper pulp in all pulp.

[0005]

The recycled paper for transfer of the present invention has a surface electric resistance of 5 × 10 ¹³ Ω or less at a water content of 4 to 6% and a temperature of 20 ° C. 8 by adding a conductive agent.
5% R. H. Adjusted to 1 × 10 ⁸ Ω or more by humidity control in the environment
And the moisture content (Y) at the time of opening the package and 20 ° C8
5% R. H. The relationship with the equilibrium moisture content (A) is expressed by the following equation (A−
6.5 ≦ Y ≦ A-4.5) and at the time of opening the package
Is characterized by having a moisture content of 6.5% or less .

The present inventor has found that the above-described copy image quality trouble has occurred.
Investigation and examination of the relationship with paper characteristics under
As a result, under high humidity environment (temperature 20 ° C, humidity 85% RH)
The surface electric resistance of the paper when humidity is controlled for 2 hours or more is 1 × 10 ⁸
If Ω or more, the density of the copied image
It has been found that trouble can be greatly improved .

At this time, HYPERLINK "http: //www.i
pdl.jpo-miti.go.jp/Tokujitu/tjitemdrw.ipdl?N0000=2
35 & N0500 = 9E # N / ;? 9 =? = <8> /// & N0001 = 33 & N0552 = 9 & N0553 =
000006 "\ t" tjitemdrw "Mechanical pulp as shown in Figure 1
Related to newspaper pulp paper and high quality waste pulp paper containing
Waste paper pulp paper under the same environment as virgin chemical pulp paper
There is no difference in surface electric resistance when humidity is adjusted by
Virgin according to JP-A-55-142799
Mechanical pulp paper can be higher than virgin chemical pulp paper.
And found that it was different. This is the same mechanical pulp
Even the waste paper pulp is used in the waste paper processing process.
This is probably due to the effect of black ink. Therefore, the same mechanical pulp
Control of electrical resistance required depending on whether virgin or waste paper
Also found that it was completely different .

[0008] Also , HYPERLINK "http: //www.ipdl.jpo-
miti.go.jp/Tokujitu/tjitemdrw.ipdl?N0000=235&N0500
= 9E # N / ;? 9 =? = <8> /// & N0001 = 33 & N0552 = 9 & N0553 = 000007 "
\ t "tjitemdrw" waste newspaper pulp paper contains many mechanical pulp as shown in Figure 2, because of the high surface electrical resistance than woodfree paper pulp paper containing no virgin chemical pulp paper and mechanical pulp are identical moisture content, containing When the water content is low, troubles such as scatter of a copy image and a large amount of residual static electricity at the time of copy discharge, such as a poor tray and sorter accommodation, occur.

The inventor of the present invention has intensively studied the relationship between the water content of the paper and the surface electrical resistance, and found that the scattering of the copy image and the failure at the time of copy discharge are in the range of 4 to 6%. When the paper surface resistance is 5
It has been found that it can be improved by adjusting the resistance to × 10 ¹³ Ω or less. That is, stable image quality and running performance can be obtained within the range of water content in paper used in normal copying. However, it is impossible to use the same type of waste paper as waste paper pulp, so even if the moisture content at the time of opening the package is specified, the equilibrium moisture differs due to the difference in the type of waste paper material and the moisture content at the time of opening the package. Even if the electric resistance is controlled under the conditions, there is a problem that the electric resistance deviates from the above-mentioned improved electric resistance range. As a result of earnestly studying the relationship between the moisture content at the time of opening the package, the moisture content at the time of opening the package (Y) and 85% R. H. The relationship with the equilibrium moisture content (A) is expressed by the following equation (A-6.5 ≦ Y ≦ A-
It has been found that 4.5) can maintain the improved electric resistance range.

[0010] Even if the moisture content at the time of opening the package can maintain this optimum range, if the moisture content exceeds 6.5%, the curl after copying becomes large, and paper jams, trays and sorters at the time of double-sided copying. Due to poor storage properties, the moisture content at the time of opening the package is adjusted to 6.5% or less, so that the surface electric resistance of the paper is adjusted to the range of the present invention, so that recycled paper having stable quality even in a high humidity environment can be obtained. It has been found that it is possible.

[0011] The surface electric resistance in the present invention is JIS
It is measured according to K 6911, and conductive agents used for control include sodium chloride, potassium chloride,
Inorganic salts such as calcium chloride and sodium alginate, and polymer electrolytes such as styrene-maleic acid copolymer and quaternary ammonium salt, and organic acid salts of potassium formate and sodium bromide, and soaps, phosphates and carboxylates Any material may be used as long as it enhances the conductivity of the paper, such as a surfactant such as zinc oxide doped with aluminum oxide, tin oxide doped with antimony, and an electronic conductive material such as titanium oxide. These conductive agents are obtained by applying the surface on a size press of a paper machine. The paper treated with these conductive agents has a surface electric resistance of 5 × 10 ¹³ Ω or less at a paper-containing moisture of 4 to 6%, and a 85% RH at 20 ° C.
H. Adjust so that it becomes 1 × 10 ⁸ Ω or more by humidity control in the environment. Accordingly, the type and amount of the conductive agent can be selected so that the surface electric resistance of the treated paper is within the above range.

The water content of the paper in the present invention is determined according to JIS.
It is measured according to P 8127, and the control of the moisture content at the time of opening the package is controlled by using 20 ° C8 of waste paper raw material used in a dryer, a calendering process, a cutting process, etc. of a paper machine.
5% R. H. Adjust to the appropriate moisture calculated from the relationship with the equilibrium moisture. 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.

Further, in order to improve the sharpness of the copy image portion, the surface unevenness is reduced by calendering or the like to make the smoothness (JIS P 8119) of the transfer paper 10 seconds or more, preferably 20 seconds or more. .

Used 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, as described above, the equilibrium moisture varies depending on the type of waste paper. , Sorting ・
The type of used paper and the mixing ratio are managed by the combination.

In the present invention, in addition to the used 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 pulp Unbleached sulphite pulp, pulp made by chemically treating wood and other fiber materials such as unbleached sulphite pulp, softwood, etc.), ground pulp obtained by mechanically pulping wood or chips, or chemicals onto wood or chips After infiltration, mechanically pulped chemi-grand pulp, chemimechanical pulp, and, after the chips have been slightly cooked, may contain virgin pulp such as 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, in order to control the equilibrium water content and to suppress the occurrence of curl after copying, the selection of the used paper and the combination and blending of virgin pulp, and the preparation of the beating degree in the preparation step 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 the like, and organic pigments such as urea resin can be used, but the ash content (JIS-
P-8128). When added, calcium carbonate is preferably blended 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 comprises:
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.

[0019]

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 of Table 1, high quality waste paper DIP40
%, Imitation waste paper DIP 30%, total waste paper pulp 70
%, And 30% of hardwood bleached kraft pulp (L-BKP) was added as a pulp other than used paper. Then, an internal addition size as shown in Table 1 was blended, and the paper stock was used to make a paper using a fourdrinier paper machine, and subjected to size press treatment to obtain 1 g / starch of starch.
m ² and 0.2 g / m ^{2 of} sodium chloride, and the water content was adjusted to 5.0% when the package was opened to obtain a recycled paper for transfer of the present invention. 20 of this recycled paper for transfer
° C 85% R.C. H. As a result of measuring equilibrium moisture after humidifying the environment for 2 hours, the surface electric resistance at that time was 8.1%.
× 10 ⁸ Ω. The surface electric resistance when the paper moisture was 5.0% was 2.51 × 10 ¹³ Ω. The copy image quality of the transfer paper in a high humidity environment was confirmed as follows. That is, this transfer paper was made at 20 ° C. and 85% R.F. H. Was left for 2 hours in the environment described above, and one-sided copying was performed with a copying machine (FX5030, manufactured by Fuji Xerox Co., Ltd.), and image density and image omission were confirmed. Immediately after opening the package with the copier, 500
Paper single-sided copy and double-sided copy were run, respectively, and a paper jam was confirmed. Table 1 shows the results. As is evident from Table 1, at 20 ° C 85% R.C. H. The surface electric resistance of the environment is set to 8.1 × 10 ⁸ Ω, and the moisture at the time of opening the package is set to 5.0%. No recycled paper was obtained.

Example 2 As shown in Example 2 in Table 1, newspaper waste paper DIP 50%, high-quality printed waste paper DIP 20%, and waste paper pulp 70% in total
20% of hardwood bleached kraft pulp (L.BKP) and 10% of refiner ground pulp (RGP) as pulp other than waste paper. Then, an internal additive size as shown in Table 1 was blended, and the paper stock was used to form a paper using a fourdrinier paper machine.
^2. Coating was performed so that the concentration of potassium chloride was 0.1 g / m ^2, and the moisture content at the time of opening the package was adjusted to 6.1% to obtain a recycled paper for transfer of the present invention. 20 ° C8 of this transfer recycled paper
5% R. H. As a result of measuring equilibrium moisture after humidifying the environment for 2 hours, the surface electric resistance at that time was 1.7 × 10
⁸ Ω. The surface electric resistance when the paper moisture was 5.1% was 2.8 × 10 ¹² Ω. This transfer sheet was evaluated in the same manner as in Example 1. Table 1 shows the results. As is evident from Table 1, at 20 ° C 85% R.
H. The surface electric resistance of the environment is set to 1.7 × 10 ⁸ Ω, and the moisture at the time of opening the package is set to 6.1%. No recycled paper for transfer was obtained.

Example 3 As shown in Example 3 of Table 1, 30% of used newspaper DIP, 30% of high quality used paper DIP, 20% of used white paper pulp, and 80% of used paper pulp were mixed in total, and pulp other than used paper was hardwood bleached. Kraft pulp (L.BKP) was blended in 20%. Then, an internal addition size as shown in Table 1 was blended, and the paper stock was used to form a paper with a fourdrinier paper machine, and subjected to size press treatment to obtain 1.2 g / m ^{2 of} starch and 0.2 g of sodium chloride.
g / m ² and the water content at the time of opening the package is 5.5.
% To obtain a recycled paper for transfer of the present invention. The transfer recycled paper at 20 ° C. and 85% R.C. H. Environment 2
As a result of measuring the equilibrium water content after the humidity control for 1 hour, the surface electric resistance at that time was 2.9 × 10 ⁸ Ω. Also,
The surface electric resistance when the paper moisture is 5.5% is 5.0 × 10
¹² Ω. This transfer sheet was evaluated in the same manner as in Example 1. Table 1 shows the results. As is evident from Table 1, at 20 ° C 85% R.C. H. The surface electric resistance of the environment is set to 2.9 × 10 ⁸ Ω, and the moisture at the time of opening the package is set to 5.5%. No recycled paper was obtained.

Example 4 As shown in Example 4 of Table 1, high quality waste paper DIP40
%, Imitation waste paper DIP 40%, total 80 as waste paper pulp
%, And 20% of bleached hardwood kraft pulp (L.BKP) was added as a pulp other than used paper. Then, an internal additive size as shown in Table 1 was blended, and the paper material was used to form a paper with a fourdrinier paper machine.
g / m ² and sodium chloride 0.2 g / m ^2, and the moisture content was adjusted to 4.7% when the package was opened to obtain the recycled paper for transfer of the present invention. This transfer paper 2
0 ° C 85% R. H. As a result of measuring equilibrium moisture after humidifying the environment for 2 hours, 9.9% was obtained, and the surface electric resistance at that time was 1.0.
× 10 ⁹ Ω. The surface electric resistance when the paper moisture was 5.0% was 3.16 × 10 ¹³ Ω. This transfer sheet was evaluated in the same manner as in Example 1. Table 1 shows the results. As is clear from Table 1, 85% at 20 ° C
R. H. The surface electric resistance of the environment is set to 1.0 × 10 ⁹ Ω,
As an effect of reducing the moisture content at the time of opening the package to 4.7%, a recycled paper for transfer free from image deterioration and free from paper jam was obtained even during running after high humidity control.

Example 5 As shown in Example 5 in Table 2, newspaper waste paper DIP 10%, high-quality printed waste paper DIP 30%, imitation waste paper DIP 20%, high quality electrophotographic paper waste paper DIP 20%, and a total of 90% of waste paper pulp are blended. Hardwood bleached kraft pulp (L.BKP) was blended as a pulp other than 10%. Then, an internal addition size as shown in Table 2 was blended, and the paper stock was used to make paper with a fourdrinier paper machine, and subjected to size press treatment to obtain 1.0 g / m ^{2 of} starch and 0.15 g / m ² of sodium chloride. Coating was performed so that the water content was adjusted to ^2, and the moisture content at the time of opening the package was adjusted to 5.3% to obtain a recycled paper for transfer of the present invention. The transfer recycled paper at 20 ° C. and 85% R.C. H. As a result of measuring the equilibrium moisture after controlling the environment for 2 hours, the surface electric resistance at that time was 5.4 × 10 ⁸ Ω. Also, the paper moisture is 5.
The surface electric resistance at 3% was 7.9 × 10 ¹² Ω.
This transfer sheet was evaluated in the same manner as in Example 1. Table 2 shows the results. As is clear from Table 2, at 20 ° C
85% R. H. Environmental surface resistance is 5.4 × 10 ⁸ Ω
As an effect of reducing the moisture at the time of opening the package to 5.3%,
Recycled paper for transfer free of image deterioration and free of paper jam was obtained even after running after high humidity control.

Example 6 As shown in Example 6 of Table 2, high-quality printed waste paper DIP60
%, Kamishiro old paper pulp 20%, high quality electrophotographic paper old paper DI
P20% and a total of 100% as waste paper pulp were blended. Then, an internal addition size as shown in Table 2 was blended, and the paper material was used to form a paper using a fourdrinier paper machine.
The starch was applied so as to be 0.6 g / m ² , PVA was 0.5 g / m ² , and sodium chloride was 0.2 g / m ² . Recycled paper for transfer was obtained. 85% of this transfer paper at 20 ° C
R. H. As a result of measuring the equilibrium moisture after humidifying the environment for 2 hours, the surface electric resistance at that time was 6.3 × 10 ⁸ Ω. The surface electric resistance when the paper moisture was 5.0% was 2.0 × 10 ¹³ Ω. Example 1
Was evaluated in the same manner as described above. Table 2 shows the results. Table 2
As is clear from FIG. H. The surface electric resistance of the environment is 6.3 × 10 ⁸ Ω, and the moisture at the time of opening the package is 4.9%. No recycled paper was obtained.

Example 7 As shown in Example 7 of Table 2, newspaper DIP 60%, imitation waste DIP 20%, high quality electrophotographic paper waste DIP20
% And a total of 100% as waste paper pulp. And
The internal size as shown in Table 2 was blended, the paper stock was used to make a paper with a fourdrinier paper machine, and the styrene-maleic acid copolymer was applied to a weight of 1.0 g / m ² by size pressing. Then, the moisture content at the time of opening the package was adjusted to 6.4% to obtain the recycled paper for transfer of the present invention. The transfer recycled paper at 20 ° C. and 85% R.C. H. As a result of measuring the equilibrium moisture after humidifying the environment for 2 hours, the surface electric resistance at that time was 1.3 × 10 ⁸ Ω. Also, the paper moisture is 5.5%
The surface electric resistance at the time of was 6.0 × 10 ¹¹ Ω. This transfer sheet was evaluated in the same manner as in Example 1. Table 2 shows the results. As is clear from Table 2, at 20 ° C 85
% R. H. The surface electric resistance of the environment is set to 1.3 × 10 ⁸ Ω, and the moisture at the time of opening the package is 6.4%. No recycled paper was obtained.

[0027]

[Table 1]

[0028]

[Table 2]

Hereinafter, a comparative example will be described. Comparative Example 1 As shown in Comparative Example 1 of Table 3, 30% of used newspaper DIP, 30% of high quality printing DIP, and 60% of used paper pulp were blended in total, and 10% of hardwood bleached kraft pulp (L · BKP) was used as pulp other than used paper. 30% of refiner ground pulp (RGP) was blended. Then, paper was made according to the formulation shown in Table 3. The image density, image omission, and paper jam of the obtained transfer paper were confirmed by the same experimental method as in Example 1. The results are shown in Table 3 below.

Comparative Example 2 As shown in Comparative Example 2 in Table 3, waste paper pulp was 0%, and pulp other than waste paper was hardwood bleached kraft pulp (L.BK).
P) was blended at 100%. Then, paper was made according to the formulation shown in Table 3. The image density, image omission, and paper jam of the obtained transfer paper were confirmed by the same experimental method as in Example 1. The results are shown in Table 3 below.

Comparative Example 3 As shown in Comparative Example 3 in Table 3, high quality printing DIP 60%, imitation DIP 10%, and a total of 70% as waste paper pulp were blended.
Hardwood bleached kraft pulp (L.
BKP) in an amount of 30%. Then, paper was made according to the formulation shown in Table 3. The image density, image omission, and paper jam of the obtained transfer paper were confirmed by the same experimental method as in Example 1. The results are shown in Table 3 below.

COMPARATIVE EXAMPLE 4 As shown in Comparative Example 4 in Table 4, used newspaper DIP 10%, high quality printing DIP 30%, imitation DIP 20%, high quality electrophotographic paper waste paper DIP 20%, and a total of 90% of waste paper pulp were blended. As a pulp, 10% of hardwood bleached kraft pulp (L.BKP) was blended. Then, paper was made according to the formulation shown in Table 4. Example 1 about the obtained transfer paper
The image density, image omission, and paper jam were confirmed by the same experimental method as that described above. The results are shown in Table 4 below.

Comparative Example 5 As shown in Comparative Example 5 in Table 4, used newspaper DIP 60%, high quality printing DIP 30%, high quality electrophotographic paper DIP10.
% And a total of 100% as waste paper pulp. And
Paper was made according to the formulation shown in Table 4. The image density, image omission, and paper jam of the obtained transfer paper were confirmed by the same experimental method as in Example 1. The results are shown in Table 4 below.

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

The recycled paper for transfer of the present invention has an 85% R.C. at 20 DEG C. despite the fact that the total pulp contains 70% or more of waste paper pulp. H. Control of surface electric resistance of paper conditioned under environmental conditions, moisture content when opening packaging and 20 ° C8
5% R. H. By specifying the moisture content at the time of opening the package from the relation of the equilibrium moisture and by making the moisture content at the time of opening the package 6.5% or less, the conventional transfer paper can be used in an indirect electrophotographic copying machine. Can be used in the same manner as electrophotographic transfer paper made of bleached virgin pulp. In particular, troubles such as copy image quality and paper jams are improved as compared with conventional transfer paper containing waste paper pulp in a high-humidity environment.

[Brief description of the drawings]

FIG. 1 shows the relationship between the surface electric resistance and the relative humidity of waste paper pulp sheets and virgin pulp sheets. The pulp sheet contains 100% of used newspaper DIP, high-quality used paper DIP (high-quality used paper), L-BKP, and RGP, and has a basis weight of 6%.
8 g / m ² , paper thickness of 105 μm, and no paper additive were used to make paper. The measurement was performed at a temperature of 20 ° C.

FIG. 2 shows the relationship between the surface electrical resistance of the paper used in FIG. 1 and the equilibrium moisture under each environment.

Continuation of front page (56) References JP-A-4-88354 (JP, A) JP-A-57-128346 (JP, A) JP-A-55-142799 (JP, A) JP-A-64-57267 (JP, A) , A) JP-A-62-198877 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 7/00 101

Claims (1)

(57) [Claims] 1. A paper containing 70% or more of waste paper pulp in all pulp, by adding a conductive agent, the surface electric resistance is 5 × 10 ¹³ Ω or less at a water content of the paper of 4 to 6% and 20 ° or less. C85% R.
H. It is adjusted to 1 × 10 ⁸ Ω or more by humidity control under the environment, and the moisture content at the time of opening the package is determined by the following formula.
And the moisture content at the time of opening the package is 6.5% or less.
A transfer paper for electrophotography, wherein A-6.5 ≦ Y ≦ A-4.5 (Y: contained at the time of opening the package
Moisture,%, A: 20 ° C 85% H. Equilibrium moisture content,
%)