JP2969368B2 - Transfer paper for electrophotography - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic transfer paper used for an electrophotographic copying machine or the like.

[Conventional technology]

Recycled paper containing deinked waste paper pulp of used paper or used newspaper and imparting indirect electrophotographic aptitude is known.

As indirect electrophotography technology is applied not only to conventional analog copiers but also to digital copiers, printers, facsimile machines, or multifunction peripherals that can be compiled, the frequency of double-sided copying and large-scale copying with these devices has increased. It is increasing rapidly.

[Problems to be solved by the invention]

If conventional recycled paper is used for the above applications, problems such as wrinkling of copies and paper jams frequently occur, especially in copy work in a high-humidity environment. It has become

An object of the present invention is to provide a used paper recycled paper which can be used for the above-mentioned severe applications which could not be considered in the conventional recycled paper. Especially the ripple is small, the curl is stabilized,
It is an object of the present invention to provide a recycled paper having an aptitude for an indirect electrophotographic hard copy apparatus in which troubles such as wrinkles and paper jams are improved.

[Means for solving the problem]

The present inventors have observed the occurrence of wrinkles and found that when copying in a high-humidity environment, unsealed paper or once copied paper was left stacked, except for some of the upper part, heat roll It was confirmed that wrinkles occurred at the trailing edge of the paper in the image fixing unit of the system. Further examination of the situation of wrinkling at the fixing section revealed that the paper on which wrinkling occurred had a water content higher by 2 to 3% at the peripheral portion than at the central portion, and the dimensions of the peripheral portion were longer than those at the central portion. It was confirmed that undulations occurred in the peripheral portion, and that when the undulations were large, the occurrence of wrinkles increased. This is because the central portion of the paper escapes from the roll nip portion first by the heat roll, and both ends remain, so that the paper swells at the central portion, breaks and is bitten into the nip portion. In addition, it was confirmed that a paper jam occurs when curl after copying generated in the fixing unit is large.

If the moisture content of the product immediately after opening (hereinafter referred to as product moisture) is high, the waving in a high-humidity environment will be small, but the curl after copying will increase, and if the product moisture is low, the curl after copying will decrease. Therefore, it was confirmed that the undulation was increased, and it was therefore important to have proper product moisture.

Furthermore, the waving of the paper in a high humidity environment is greatly affected by the equilibrium moisture in the environment. Conventional recycled paper, which has a high mechanical pulp specific gravity, easily absorbs moisture and has a high equilibrium moisture.Therefore, even with paper that has an appropriate product moisture at the beginning of opening, the difference between the moisture content of the peripheral part and the central part gradually increases, The wrinkles often cause wrinkles. Irrespective of virgin pulp and waste paper pulp with low equilibrium moisture, the more chemical pulp (CP), the more the product moisture is appropriate, the smaller the water difference between the periphery and the center of the paper, the less the ripple,
It was confirmed that the occurrence of wrinkles was small. And it was confirmed by experiments that the occurrence of wrinkles was sharply reduced when the total ratio of CP among the pergin pulp and the waste paper pulp in all the pulp was 70% or more.

In addition, conventional recycled paper has a high mechanical pulp ratio in the total pulp, easily absorbs moisture, and has a high equilibrium moisture, so the product moisture is usually high, the curl is unstable, and paper jams occur. . On the other hand, the recycled paper having a high CP ratio, which is the electrophotographic transfer paper of the present invention, has a low equilibrium moisture, so that a proper product moisture can be stably secured, so that the curl is stabilized and the paper jam is reduced. You can.

The electrophotographic transfer paper of the present invention contains at least 40% of waste paper pulp, the total ratio of chemical pulp of virgin pulp and waste paper pulp in all pulp is at least 70%, and the water content is 3.5 to 6.0. %.

In the electrophotographic transfer paper of the present invention, it is necessary that the total CP content of the virgin pulp and the waste paper pulp is 70% or more of the total pulp.

The used paper pulp used in the present invention is used for dismantling unprinted used paper such as cut-off, waste paper, width-reduced waste paper, white paper, special white paper, medium white paper, white paper loss, etc. generated in bookbinding, printing plants, cutting shops, etc. Waste paper pulp and high quality paper, high quality coated paper, medium quality paper,
For medium quality coated paper, paper change, etc., planographic, letterpress, intaglio printing, etc.
Electrophotographic method, heat-sensitive method, thermal transfer method, pressure-sensitive recording method,
Ink jet recording method, used paper printed with carbon paper, used paper, water-based or oil-based ink, used paper written with a pencil, etc., and pulp (hereinafter abbreviated as DIP) deinked after dissociation can be used. In addition, in the case where the blending ratio of waste paper pulp in the transfer paper is increased to 70% or more in CP, the blending of the waste paper pulp obtained by disintegrating or deinking the waste paper containing a large amount of chemical pulp among the aforementioned waste papers may be used. .

Virgin CP includes hardwood bleached kraft pulp (LB
KP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), softwood unbleached kraft pulp (NU
KP), hardwood bleached sulphite pulp (LBSP), softwood bleached sulphite pulp (NBSP), hardwood unbleached sulphite pulp (LUSP), softwood unbleached sulphite pulp (NUSP), soda pulp and other wood and other fiber raw materials And pulp produced by the treatment.

In the present invention, in addition to the above CP, wood or chips are used as they are, or after heat treatment, mechanically treated mechanical pulp (MP), after the chemical solution is impregnated into the wood or chips, and then mechanically pulped. Virgin pulp such as semi-chemical pulp (SUP) pulverized by a refiner after digesting the chemically ground pulp, the chemomechanical pulp, and the chips to be slightly softened may be contained.

As described above, in order to increase the equilibrium moisture of the paper, it is necessary to reduce the amount of the pulp other than CP as much as possible. The pulp is contained at a ratio of 30% or less, preferably 20% or less.

Fillers that can be used in the electrophotographic transfer paper of the present invention include heavy calcium carbonate, light calcium carbonate,
Calcium carbonate such as chalk, kaolin, calcined clay,
Inorganic fillers such as silicates such as pyrophyllite, sericite, and talc, and silicic acids such as white carbon and silica powder, and organic fillers such as urea resin can be used. , Preferably 10% or less. It is particularly desirable to add 10% or less of calcium carbonate from the viewpoint of maintaining image quality in the electrophotographic system.

Rosin sizing agents, synthetic sizing agents, petroleum resin sizing agents,
A sizing agent such as a neutral sizing agent can be used, and an appropriate sizing agent such as a sulfate band or a cationized starch is used in combination with a fixing agent for maintenance. At this time, a neutral sizing agent, particularly an alkenyl succinic anhydride-based sizing agent, is preferred from the viewpoint of storage stability and from the viewpoint of runnability in an electrophotographic copying machine, printer or the like.

Further, preparation of raw materials and control of production conditions are performed in order to impart electrophotographic suitability such as copy suitability and running property. That is, the raw pulp is appropriately beaten so that the equilibrium moisture does not increase. Also, 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 used in a size press of a paper machine. And transfer the surface electric resistance of the transfer paper to 10 ⁹
It is preferably set to 10 ¹⁰ Ω (temperature: 20 ° C., humidity: 65% RH) (according to JIS K6911).

Also, in order to improve the sharpness of the copy image area, the surface unevenness is reduced by calendering processing, etc.,
The smoothness (JIS P8119) of the transfer paper is preferably 10 seconds or more, particularly preferably 20 seconds or more.

In addition, as described above, the product moisture immediately after opening the paper machine dryer and calendering process so that the moisture content is in the range of 3.5 to 6.0% in order to suppress waving and curling after copying. It is managed in the cutting process. 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.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

Example 1 As shown in Example 1 in Table 1, chemical pulp (CP)
As a pulp other than CP, 30% of ground pulp (GP) was blended, and filler and internal sizing agent as shown in Table 1 were blended. .
Paper was made to be 1%. In addition, in order to provide indirect electrophotographic aptitude, starch was reduced to 1 g / g
m ² and sodium chloride 0.2 g / m ² to obtain an electrophotographic transfer paper of the present invention. 20 ° C, 65% of this transfer paper
The equilibrium moisture of RH was 8.1%.

The suitability of the transfer paper for copying in a high-humidity environment was confirmed as follows. That is, 100 sheets of this transfer paper were stacked in an environment of 20 ° C. and 85% RH, left on a desk for one hour, and the copying machine (F
X5990, manufactured by Fuji Xerox Co., Ltd.), performed one-sided copy, one-sided multiplexed copy, and two-sided copy.
The number of paper jams was confirmed. Table 1 shows the results.

As is evident from Table 1, the effect of blending 70% of used white paper pulp as CP is that the use of unprinted waste paper, with less wrinkling, less paper jams, and less jamming even after running in high humidity conditions. As a result, transfer paper having high whiteness was obtained.

Example 2 As shown in Example 2 in Table 1, 60% of Kamishirasuko Pulp and 30% of Virgin LBKP, a total of 90%, were mixed as CP.
As pulp other than CP, thermomechanical pulp (TM
P) was blended at 30%, fillers and internal sizing agents as shown in Table 1 were blended, and paper was made so that the product moisture was 4.8%. Furthermore, in order to impart indirect electrophotographic aptitude, starch was subjected to 1 g / m ² and sodium chloride 0.2 g / m ² by size pressing.
Thus, the transfer paper for electrophotography of the present invention was obtained. The equilibrium water content of this transfer paper at 20 ° C. and 65% RH was 7.7%. The transfer paper was checked for wrinkles after copying and the number of paper jams in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the effect of blending 90% of CP was that no wrinkles were generated even during running after high-humidity and humidity control, and transfer paper free of paper jam was obtained. Furthermore, since the amount of high-retention pulp other than CP was small and unprinted waste paper and virgin LBKP were used as CP, transfer paper having higher whiteness than in Example 1 was obtained.

Example 3 As shown in Example 3 in Table 1, as the CP, imitation waste paper DI such as high quality paper, high quality coated paper, offset printed matter, and thermal paper
60% P and 10% virgin LBKP, total 70%, CP
As pulp other than the above, 20% of TMP and 10% of GP were blended, fillers and internal sizing agents as shown in Table 1 were blended, and paper was made so that the product moisture became 5.5%. Furthermore, in order to impart indirect electrophotographic aptitude, starch is subjected to size press
1 g / m ^2, was coated such that the sodium chloride 0.2 g / m ^2, to obtain a transfer paper for electrophotography of the present invention. 20 ℃ of this transfer paper, 65
The equilibrium moisture at% RH was 8.0%. The transfer paper was checked for wrinkles after copying and the number of paper jams in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the effect of blending 70% of CP was that transfer paper with less wrinkling and less paper jam was obtained even during running after high humidity conditioning.

Example 4 As shown in Example 4 in Table 1, as the CP, imitation used paper DI such as high quality paper, high quality coated paper, offset printed matter, and thermal paper
40% P and 30% virgin LBKP, total 70%, CP
As other pulp, 20% of GP and 10% of chemical ground pulp (CGP) were blended, fillers and internal sizing agents as shown in Table 1 were blended, and paper was made so that the product moisture was 4.2%. . Furthermore, in order to impart indirect electrophotographic aptitude, starch was subjected to 1 g / m ² and sodium chloride 0.2 g /
It was coated so as to m ^2, and to obtain a transfer paper for electrophotography of the present invention. The equilibrium water content of this transfer paper at 20 ° C. and 65% RH was 8.2%. The transfer paper was checked for wrinkles after copying and the number of paper jams in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the effect of blending 70% of CP was that transfer paper with less wrinkling and less paper jam was obtained even during running after high humidity conditioning. Further, as compared with the case of Example 3, transfer paper having higher whiteness was obtained.

Example 5 As shown in Example 5 in Table 1, imitation waste paper DI such as high quality paper, high quality coated paper, offset printed matter, and thermal paper was used as CP.
20% of P, 50% of LBKP of virgin, CP in newspaper DIP 3
%, A total of 73%, used as pulp other than CP
Combined with 27% of pulp content other than CP in DIP, and with filler and internal sizing agent as shown in Table 1, product moisture is 4.5%
Paper was made. Further, in order to impart indirect electrophotographic aptitude, starch was coated by a size press treatment so as to have a concentration of 1 g / m ² and sodium chloride of 0.2 g / m ² , thereby obtaining an electrophotographic transfer paper of the present invention. The equilibrium water content of this transfer paper at 20 ° C. and 65% RH was 8.1%. The transfer paper was checked for wrinkles after copying and the number of paper jams in the same manner as in Example 1.
Table 1 shows the results.

As is evident from Table 1, as a result of adding 73% of CP, transfer paper with less wrinkling and less paper jam was obtained even during running after high humidity conditioning.

In addition, the incorporation of more virgin LBKP and newspaper waste paper DIP, which are less expensive than high quality imitation waste paper DIP, resulted in inexpensive transfer paper.

Furthermore, virgin that has not been subjected to waste paper deinking treatment, that is, has low mechanical and chemical damage to pulp
By containing a large amount of LBKP, transfer paper with little paper dust generated in the copying machine was obtained.

Example 6 As shown in Example 6 in Table 1, 70% of high quality electrophotographic paper waste paper DIP was blended as CP, and as pulp other than CP,
Refiner groundwood pulp (RGP) 10% blended with TMP20%
Fillers and internal sizing agents as shown in Table 1 were blended, and paper was made so that the product moisture was 3.5%. To further impart adaptability for indirect electrophotography, a size press, was applied so that the starch 1 g / m ^2, and sodium chloride 0.2 g / m ^2,
An electrophotographic transfer paper of the present invention was obtained. 20 ℃ of this transfer paper,
The equilibrium moisture at 65% RH was 7.9%. The transfer paper was checked for wrinkles after copying and the number of paper jams in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, as a result of the addition of 70% of CP, transfer paper free from wrinkling and having little paper jam was obtained even after running after high humidity conditioning.

Example 7 As shown in Example 7 in Table 1, as a CP, 50% of high-quality electrophotographic paper waste paper DIP and 20% of virgin LBKP were blended.
As pulp other than P, 30% GP was blended, fillers and internal sizing agents as shown in Table 1 were blended, and paper was made so that the product moisture became 6.0%. Further, in order to impart indirect electrophotographic aptitude, starch was coated by a size press treatment so as to have a concentration of 1 g / m ² and sodium chloride of 0.2 g / m ² , thereby obtaining an electrophotographic transfer paper of the present invention. The equilibrium water content of this transfer paper at 20 ° C. and 65% RH was 7.9%. The transfer paper was checked for wrinkles after copying and the number of paper jams in the same manner as in Example 1. Table 1 shows the results.

As is clear from Table 1, the effect of blending 70% of CP was that transfer paper with less wrinkling and less paper jam was obtained even during running after high humidity conditioning.

Comparative Examples 1 to 3 In order to compare with Examples 1 and 2, as the CP, 40-60% was blended by combining Kamishirako Pulp and virgin LBKP, and the product moisture, filler, Paper was made with the internal sizing agent and surface sizing agent formulation. With respect to the obtained transfer paper, the number of occurrences of wrinkles and paper jams after copying was confirmed by the same experimental method as in Example 1. Further, at 20 ° C. ,
An equilibrium moisture of 65% RH was confirmed. The results are shown in Table 2 below.

Comparative Examples 4 to 6 For comparison with Examples 3 to 5, as the CP, imitation waste paper DI such as high quality paper, high quality coated paper, offset printed matter, and thermal paper
Combining P and virgin LBKP, blending 40-60%,
Product moisture, filler, internal sizing agent as shown in Table 2,
Paper was made with a surface sizing agent formulation. With respect to the obtained transfer paper, the number of occurrences of wrinkles and paper jams after copying was confirmed by the same experimental method as in Example 1. 20 ° C, 65% RH
The equilibrium water content was confirmed. The results are shown in Table 2.

Comparative Examples 7 and 8 For comparison with Examples 6 and 7, as a CP, a combination of high quality waste paper for electrophotography DIP and virgin LBKP was used.
~ 60%, product moisture, filler, as shown in Table 2,
Paper was made with the internal sizing agent and surface sizing agent formulation. With respect to the obtained transfer paper, the number of occurrences of wrinkles and paper jams after copying was confirmed by the same experimental method as in Example 1. further
The equilibrium moisture at 20 ° C. and 65% RH was confirmed. The results are shown in Table 2.

Comparative Examples 9 and 10 In order to confirm the effect of product moisture on wrinkles and paper jams, the product moisture was reduced by 6.9% using the same pulp formulation, filler, internal sizing agent, and surface sizing agent formulation as in Examples 1 and 7.
And 6.2%. With respect to the obtained transfer paper, the number of occurrences of wrinkles and paper jams after copying was confirmed by the same experimental method as in Example 1. 20 ° C, 65%
The equilibrium moisture of RH was confirmed. The results are shown in Table 2.

[Effect of the Invention] Since the electrophotographic transfer paper of the present invention has the above-described configuration, indirect electrophotographic hard copy in a high humidity environment, which cannot be used with conventional recycled paper containing waste paper pulp, It can be applied to a severe copying operation by the apparatus, and in particular, the ripples are small, the curl is stabilized, and troubles such as wrinkles and paper jams are improved.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Katsumi Harada 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd. Ebina Office (56) References JP-A-58-40556 (JP, A) JP-A-63- 309700 (JP, A) JP-A-55-142799 (JP, A)

Claims (1)

(57) [Claims] 1. A paper pulp containing at least 40% waste paper pulp, a chemical pulp ratio of at least 70% of the total pulp, and a water content of 3.5%.
The transfer paper for electrophotography, characterized in that the content is up to 6.0%.