JPH08202069A - Method for producing transparent transfer paper for electrophotography - Google Patents

Abstract

(57) [Summary] [Purpose] A transparent transfer paper for electrophotography, which uses a pulp material that has been subjected to a high beating degree, has excellent transparency and dimensional stability, and has less dents after heating printing on an electrophotographic copying machine. A method for manufacturing the same is provided. [Structure] Canadian Standard Freeness is 20
Papermaking using pulp beaten to less than 10 ml, water content 10
% To less than 5%, and saturated steam is sprayed, and after 1 second or more and 5 seconds or less, a size press treatment is performed, followed by drying with a cylinder dryer to produce a transparent transfer paper for electrophotography.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a transparent transfer paper for electrophotography, and in particular, it uses a pulp raw material that has been subjected to a high beating degree treatment, and has excellent transparency and dimensional stability, and electrophotography. The present invention relates to a method for producing a transparent transfer paper for electrophotography, which is less likely to have roughness after being printed by heating in a copying machine.

[0002]

2. Description of the Related Art A second original drawing for a positive image, which is one of the uses of transparent transfer paper for electrophotography, is designed to ensure good image reproducibility when printing a positive image. It is necessary to suppress the occurrence of dimensional fluctuations, curls and lumps as much as possible.

In a conventional method for producing a transparent transfer paper for electrophotography using a pulp raw material which has been subjected to a high beating degree treatment, the freeness of the pulp is raised in order to prevent curling or lumpiness after heating printing. Alternatively, measures such as increasing the tension of the wet paper web with a dryer are taken, but this causes a decrease in transparency.

There is also a method of stabilizing the dimensions by impregnating a water-soluble or solvent-soluble resin, but there is a problem that the working environment is deteriorated due to the odor generated during heating printing in an electrophotographic copying machine. As described above, no manufacturing method has been established that simultaneously satisfies the characteristics such as curl and graininess in an electrophotographic copying machine and transparency.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, there is provided a method for producing a transparent transfer sheet for electrophotography which is excellent in transparency, has less dimensional variation, curl and flicker after heating and printing in an electrophotographic copying machine and does not generate odor. Is to provide.

[0006]

The method for producing a transparent transfer paper for electrophotography of the present invention is a papermaking process using pulp beaten to a Canadian standard freeness of 20 ml or less, dried to a water content of 10% or less, and saturated steam is generated. Spray 1
It is characterized in that it is manufactured by performing a size press treatment after a lapse of from 2 seconds to 5 seconds, and drying with a cylinder dryer.

The method for producing the transparent transfer paper for electrophotography of the present invention will be described in detail below. When the electrophotographic transparent transfer paper is applied to an electrophotographic copying machine, lumpiness occurs when it is heated for toner fixing, but this is because unevenness in local dimensional change occurs as the water content flies. The dimensional change due to the change in water content is reduced by repeating rewetting and re-drying.

For this reason, after the size press treatment, the dimensional stability is usually increased, and it becomes difficult for the lumps to occur. However, in the electrophotographic transparent transfer paper produced by making pulp with a high beating degree, the sheet has a high density,
Since the water absorptivity is poor, the amount of liquid absorbed by the size press is small, which may rather increase the moisture unevenness of the sheet and aggravate blistering. Unless the sheet water content after size pressing exceeds 20% on average, the dimensional stabilization effect due to rewetting cannot be obtained.

The method for producing a transparent transfer paper for electrophotography of the present invention, that is, after drying to a water content of 10% or less, by spraying saturated steam before the size press, moisture is absorbed on the sheet before liquid absorption in the size press. Not only is added, but also swells the sheet, facilitates liquid absorption, increases the water content after size press, and also reduces water unevenness of the wet paper.

However, if the size press is entered within 1 second after the saturated vapor spray, the swelling effect of the sheet cannot be exerted, and the occurrence of bouncing after heating and printing in the electrophotographic copying machine is not reduced. Also, when 5 seconds or more has passed from the saturated vapor spray, the size press enters the size press, the reduction of water due to evaporation from the sheet surface cannot be ignored, and a sufficient re-wetting effect cannot be obtained. Occurrence of fluttering after heating printing does not decrease.

The saturated vapor spraying mechanism of the present invention is one in which slender nozzles such as fludex, steam foil, and gloss roll are provided in the widthwise direction of the paper, and tubular spray nozzles are arranged at regular intervals in the widthwise direction of the paper. Something is used.

The size press device of the present invention is a mold for forming a pound between two rolls, such as a vertical type or an inclined type.

The pulp used in the electrophotographic transparent transfer paper of the present invention includes NBKP, LBKP, NBSP and L.
BSP etc. are mentioned. Several kinds of them can be mixed and used at a ratio according to the purpose.

Various refiners such as a disc refiner, a conical refiner, and a cylindrical refiner can be used as the beating machine of the present invention.

The paper is produced by a Fourdrinier paper machine having an air cushion head box or a hydraulic head box, a twin wire paper machine, an on-top twin wire paper machine, or the like.

The press arrangement includes straight through, transfer, try nip, twin bar, extended nip and the like, and it is possible to combine them.

Further, if necessary, it is smoothed by a machine calendar, a soft calendar, a super calendar, a thermal calendar or the like.

[0018]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples. The present invention is not limited to the embodiments.

Examples 1 and 2 Using a 0.6% pulp slurry of NBKP beaten to a freeness of 15 ml, a fourdrinier machine was used to produce paper at a speed of 100 m / min.
After making a transparent transfer paper for electrophotography with a basis weight of 75 g / m ² and drying it to a moisture content of 8%, install steam foil equipment manufactured by Aikawa Tekko Co., Ltd. on both sides of the sheet, spray saturated steam, and then After the swelling time shown in Table 1, a 2% oxidized starch solution (manufactured by Nippon Shokubai Co., Ltd .; M
S3800) was applied and dried with a cylinder dryer, and then machine calendering was performed so that the density became 0.90 g / cm ³ . The quality characteristics of the obtained electrophotographic transparent transfer paper are summarized in Table 1 below.

Example 3 A transparent transfer paper for electrophotography was obtained by the same method as in Example 1, except that the saturated vapor applying device was Fludex.

Example 4 In Example 1, the saturated vapor applying device was a device in which 5 mmφ holes were made at 50 mm intervals on the side of the 100 mmφ steam pipe facing the paper, and a device for spraying steam from the holes was installed on both sides of the sheet. Transparent electrophotographic transfer paper for electrophotography was obtained by the same method except for the above.

Comparative Example 1 A transparent transfer paper for electrophotography was obtained in the same manner as in Example 1 except that saturated vapor was not applied.

Comparative Examples 2 to 3 In Example 1, except that the swelling time shown in Table 1 was used.
Transparent transfer papers for electrophotography were obtained by the same method.

The electrophotographic transparent transfer papers produced in the above Examples and Comparative Examples were evaluated by the following evaluation methods,
The results are summarized in Table 1 below. [Transparency] Transparency is a value obtained by subtracting the opacity measured according to the B method of JIS P8138 from 100%, and is 6 for an electrophotographic transparent transfer paper having excellent transparency.
8% or more, preferably 69% or more is necessary.

[Bobbling] Bottling is the result of visual evaluation of blistering on the paper surface immediately after printing with an electrophotographic copying machine (FX5080, manufactured by Fuji Xerox Co., Ltd.). Δ: Many were marked as × The lower limit of quality is Δ, but ◯ is preferable.

[Shrinkage] The shrinkage is the shrinkage of the long side (flow direction) immediately after printing of an A1 size sample by an electrophotographic copying machine (FX5080, manufactured by Fuji Xerox Co., Ltd.), and has excellent dimensional stability. 0.70 as a transparent transfer paper for electrophotography
% Or less, preferably 0.68% or less.

[0027]

[Table 1]

[0028]

EFFECT OF THE INVENTION By the method for producing a transparent transfer paper for electrophotography of the present invention, it is possible to produce a transparent transfer paper for electrophotography which has little dimensional stability after copying in an electrophotographic copying machine and is excellent in dimensional stability. .

Claims (1)

[Claims] 1. Paper making using pulp beaten to a Canadian standard freeness of 20 ml or less, dried to a water content of 10% or less, sprayed with saturated steam for 1 second or more,
A method for producing a transparent transfer paper for electrophotography, which comprises performing size press treatment within 5 seconds and drying with a cylinder dryer.