JPH045662A - Transfer paper for electrophotography - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic transfer paper. More specifically, the present invention relates to a transfer paper used in an electrophotographic copying machine that thermally fixes toner and has good runnability and workability in the copying machine.

[Prior Art] Transfer paper used in electrophotographic copying machines is required to have good runnability and workability in the copying machine, and in particular to minimize curling that occurs after toner is transferred.

In electrophotographic copying machines, a method is adopted in which an image is formed on transfer paper using toner 4 (4), and then the toner is bonded under heat and pressure to fix it on the paper, and this temperature is usually 180° C. or higher. In other words, after forming an image with toner, the transfer paper is passed under pressure between a metal roll heated to a high temperature and an elastic roll.At this time, the transfer paper undergoes a complex mechanism such as drying and shrinkage due to heating and pressure. Curl occurs.

Is transfer paper the raw material for conventional transfer paper? Vagin valves such as bleached hardwood valves have been mainly used in V-printing machines due to their runnability and workability, but in recent years due to social demands, waste paper containing mechanical pulp such as newsprint and magazine paper has been used as raw material for transfer paper. Regeneration valves have come into use. However, when a used paper recycling valve containing mechanical pulp is blended, the equilibrium moisture content of the transfer paper at each relative humidity increases due to the lignin contained in the mechanical pulp, which increases the curling of the transfer paper after copying, resulting in poor runnability and workability. There was a problem in that the quality of the data deteriorated and copying was sometimes impossible.

[Problems to be Solved by the Invention] In view of the current situation, the present inventor has made extensive research into the relationship between the equilibrium moisture content of paper at a constant humidity and the curl generation mechanism, and what factors determine the equilibrium moisture content of paper. As a result of research, it was found that the higher the equilibrium moisture content (yes, the curl after copying increases, and the more fine fibers in the bulbs that make up the paper, the higher the equilibrium moisture content. The inventors discovered that the more the moisture content is reduced, the lower the equilibrium moisture content at high humidity is, and the curling after copying becomes smaller even if the transfer paper is left under high humidity for a long time, leading to the completion of the present invention.

Therefore, an object of the present invention is to provide an electrophotographic transfer paper that exhibits minimal curling after copying in an electrophotographic copying machine even when the transfer paper is left in high humidity for a long time (and has extremely good runnability and workability). It's about doing.

Note that the transfer paper includes not only sheet paper but also continuous slip paper.

[Means for Solving the Problems] The present invention is characterized in that the number average fiber length of the bulbs constituting the paper is 0.43.
The electrophotographic transfer paper is characterized in that the proportion of fibers with a diameter of mm or more and 0.1 mm or less is 33% or less.

The number average fiber length and equilibrium moisture content of the raw material valve used in the present invention were measured by the following method.

Several inches long, 7! ll''''''' method Traditionally, the fiber length distribution of bulbs is usually measured as a weight distribution, but in the case of weight distribution, the influence of fine fibers on the overall fiber length distribution is very small, so this method is Since this method is useless for the purpose of evaluating the amount of fine fibers, which have an important effect on the equilibrium moisture content of paper, as in the present invention, we adopted a number-average fiber length distribution measurement method that can sensitively measure the amount of fine fibers.

There are no particular restrictions on the method for measuring fiber length distribution, but examples include a method in which bulb fibers are dispersed on a slide glass and then fixed, and the number average fiber length distribution is determined by microscopic observation, and a dilute solution of bulb fibers is introduced into a capillary tube and optically measured. A device (Fiber 5) that electrically measures the number average fiber length distribution via the system
izeAnalyzer, FS-200, manufactured by Kajaani, Finland), etc. can be used. Although the results of measuring the number fiber length distribution by microscopic observation are highly reliable, the measurement requires a lot of effort and time.
-1yze, FS-200, manufactured by Kajaani).

Nisho Riko Yu 1 Yu transfer paper in an environment with a temperature of 20°C 12 at a temperature of 65%
After adjusting the humidity for a period of time, the moisture content is measured according to JIS P-8127.

The number average fiber length of the raw material valve of the present invention is 0.43 mm or more, and the ratio of the number of fibers with a length of 0.1 nm or less is 3.
There is no particular restriction on the method of reducing the percentage to 3% or less, but the first method is to selectively remove fine fibers from the valve slurry in the pre-papermaking stage, for example by increasing the size of the wire mesh in the washing process. This can be achieved by increasing the amount of washing water, or by using a screen to remove fine fibers.

The second method is to remove a portion of machine white water with a relatively high concentration of fine fibers during the papermaking process, and the objective can be achieved by removing at least 5% or more of the white water amount.

In the above method, the number average fiber length of the bulb and the amount of fine fibers are adjusted, that is, the number average fiber length of the bulb is adjusted to 0.
By controlling the ratio of the number of fine fibers of 43 mm or more and 0.1 mm or less to 33% or less, a transfer paper with good runnability and workability in a copying machine can be obtained.

As the raw material valve used in the present invention, a hardwood bleached bulb, a softwood bleached bulb, a deinked waste paper bulb, or a mixture thereof may be used as desired. In particular, the effects of the present invention are remarkable when a recycling valve for used newspapers or used magazines containing a mechanical valve is used as the deinking used paper valve.

Furthermore, the present invention is applicable to transfer paper produced by known papermaking chemicals and paper machines.

[Example] The present invention will be described in more detail with reference to Examples below, but of course the present invention is not limited thereto.

Example 1 and Example 2 Freeness 410m Q (C, S,
F.

Hardwood bleached pulp (Canadian standard freeness) beaten to
In Example 1, this valve was separated into long fibers and fine fibers using a bird screen (slit width 0.2 mm1), the long fibers were used as an accept valve and the main raw material for papermaking, and all of the fine fibers were used as the main raw material for paper making. The remaining 20% by weight of the bulb discharged out of the papermaking system was added and used, and the following papermaking chemicals and fillers were added in absolute dry terms per bulb to prepare a paper stock.

In Example 2, the following papermaking chemicals and fillers were added to the paper stock without separating the valves using a bird screen, and 10% of the machine white water was discharged outside the papermaking system during papermaking.

Alkenyl succinic anhydride 0.09% by weight (Fiberan 81, manufactured by Tamago National Co., Ltd.) Cationized starch 0.5% by weight (Kate F, manufactured by Tamago National Co., Ltd.) Bandate sulfate 0.2% by weight Light calcium carbonate 5.0 Weight% (TP-12
1S, manufactured by Okutama Kogyo Co., Ltd.) This paper stock was used to make paper using a fourdrinier paper machine, passed through a size press and a machine calender, to a paper weight of 64 g/m2. Density 0.7g/cm3. A transfer paper with a paper moisture content of 5.0% was obtained.

As a size press chemical, size press starch (oxidized starch, Tamago Nisu B, manufactured by Oji Cornstarch Co., Ltd.) and styrene-maleic acid copolymer (Polymaron 385, manufactured by Arayo Kagaku Co., Ltd.) were used at a weight ratio of 5:02. The amount of this mixture applied to paper was 0.6 g/m2. The resulting transfer paper (A
4 size) at 20° C. and 65% R) IF after 12 hours of humidity control, curling, runnability, and workability in a copying machine were evaluated.

(Evaluation method of transfer paper) To evaluate the runnability and workability of transfer paper in a copying machine, 1000 sheets of A4 size transfer paper were copied using a Fuji Xerox electrophotographic copying machine (model 5990, with sorter). It was done.

(1) Curling As shown in Figure 1, grasp one side of the curled transfer paper with your hand, read the height (L) of the arc on the opposite side, and
It is shown as the average value of the reading value of 0 sheets. The greater the height of the arc, the greater the curl.

(2) Runnability Shown as the number of times troubles such as paper jams occurred while copying 1000 sheets of transfer paper.

(3) Workability: 1000 sheets of transfer paper were copied, and evaluation was made based on the number of sheets of transfer paper that entered the sorting turbine after copying.

(4) Measurement of amount of paper dust While copying 1000 sheets of transfer paper, paper dust adhering to the surface of the photosensitive drum of the copying machine was collected and its weight was measured.

Example 3.4 and Comparative Example 1.2 Freeness 410m as valve raw material for Example 3.4 and Comparative Example 1! 2 (LB beaten to C, S, F heat
KP, deinked freeness 200m 9 (C,S
.

F, ), old newspaper bulbs with a whiteness of 70% and freeness 350m E (C, S, F, l, high quality waste paper bulbs with a whiteness of 70% were mixed in a weight ratio of 20:60.20).

In Example 3, the same treatment as in Example 1 was applied to the valve raw material,
30% of the fine fibers were discharged out of the paper making system, and the rest was combined with the long fibers to make paper stock.

In Example 4, the same treatment as in Example 2 was performed, and 25% of the machine white water was discharged outside the papermaking system.

In Comparative Example 1, separation of fine fibers and discharge treatment of machine white water containing fine fibers to the outside of the papermaking system were not performed.

In Comparative Example 2, LBKP and deinked newspaper waste valve were used as valve raw materials in a weight ratio of 20+80, and as in Comparative Example 1, fine fibers were separated and machine white water containing fine fibers was discharged to the outside of the paper making system. No treatment was applied.

The amounts of papermaking chemicals and fillers added, and the papermaking conditions were as shown in Examples 1 and 2.
A transfer paper was made in the same manner as above, and the transfer paper was further evaluated.

Table 1 shows the evaluation results of the transfer papers from Example 1 to Comparative Example 2.

As is clear from Table 1, the curling, runnability and workability after copying of the transfer paper made using the valve raw material having the characteristics of the present invention are good, whereas the paper of the present invention It can be seen that the curling, runnability, and workability after copying of transfer paper made from valve raw materials that do not have the following characteristics are inferior.

[Effects of the Invention] By adjusting the fiber length distribution of the valve raw material used in the production of electrophotographic transfer paper, the transfer paper that has been conditioned at high humidity for a long time has less curl after copying and has improved runnability. This also has the effect of significantly improving workability.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing curl measurement after copying of A4 size transfer paper. The curl is indicated by the average value of the measured values of L (mm). 1...L (height of arc)

Claims (1)

[Claims] An electrophotographic transfer paper, characterized in that the number average fiber length of the pulp constituting the paper is 0.43 mm or more, and the ratio of the number of fibers with a fiber length of 0.1 mm or less is 33% or less.