JPS59133092A - Recording sheet - Google Patents

Abstract

PURPOSE:To obtain a high-quality image substantially free from drop-out or irregularity in recording without requiring any special treating on a mechanical system, by setting the GS smoothness of a recording surface of a recording sheet to be not lower than 300sec. CONSTITUTION:A specimen 1 is clamped between a rigid body 2 having a gas- penetrating hole 3 and a gas-shielding rigid body 4, then the pressure in the hole 3 is reduced to measure the period of time required for air to pass therethrough, thereby measuring the GS smoothness of the specimen 1. The thus obtained GS smoothness is an evaluation of total uniformity including the conditions of both surfaces of the specimen 1, uniformity of thickness and that of density. A recording sheet having high uniformity in terms of the GS smoothness of not lower than 300sec is used, and a heat-sensitive color forming layer, a coloring material adsorbing material layer or a proton doner layer is provided thereon to obtain a heat-sensitive recording paper, a heat-sensitive transfer recording paper on an electrostatic recording paper.

Description

[Detailed description of the invention] ＼ Industrial application field The present invention is - Facun Milli, Printer, Plotter.

This invention relates to recording sheets for information recording devices such as copying machines.

Conventional structure and problems Conventional recording sorting for various information recording devices such as electrostatic recording paper, thermal recording paper, and thermal transfer paper has many minute thickness unevenness and density unevenness, so high-density recording Even when a head is used, dropouts and uneven recording occur, making it difficult to obtain high-quality characters and images.Purpose of the InventionThe present invention is an information recording device that uses a mechanically special head. OBJECT OF THE INVENTION The present invention aims to provide a recording sheet that can produce high-quality characters and images with almost no dropouts or recording unevenness even without handling. This is a recording sort with a surface, and it is possible to obtain a high quality image by improving the uniformity of recording sorting.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below. First, an outline of CS smoothness will be explained.

In the conventional smoothness measurement method (JISP'8119 Beck smoothness measurement method), a sample is pressed between a glass root and a comb sheet, and the time required for a certain amount of air to pass through a small gap between the glass surface and the sample surface is measured. However, the present inventors improved this by sandwiching the sample between glass plates (Glass Sandwich - G, s), and similarly expressed the smoothness by the air passage time ( (Details will be described later.) Therefore, compared to the conventional Bekk smoothness that evaluates only the condition of one side of the sheet, S smoothness evaluates the overall uniformity such as thickness unevenness and density unevenness, including the condition of both sides of the sample. It is something.

For example, the Bekk smoothness of a sample surface in its natural state, where the surface is mirror-like and one back surface is rough (irregularities of several tens of μm) is:
The rubber sheet compensates for the unevenness on the back, so it takes several thousand seconds.

On the other hand, with GS smoothness, the time is less than 100 seconds because the back surface is not complemented.

Such a difference in smoothness corresponds well to the recording state of recent high-density image recording. In other words, in order to make recording devices smaller and more precise, the platen surface is becoming harder, and recording sheets with only high Bekk smoothness are prone to dropouts and recording unevenness, making it difficult to produce high-quality characters and I can no longer get images.

The present invention will be described in detail by making various types of recording sheets using the S smoothness as a measure as described above, and describing the correspondence with image quality.

Example 1 A recording sheet was prototyped by coating a base paper with a thermosensitive coloring material, and 6
An image was recorded using a dot/mm line-shaped platen roll with a JIS rubber hardness of 80.

The base paper is high-quality paper (Jujo Seishigari, Kinno 1 tsubo weight 66,
! 7/m'). This GS smoothness is about 30 seconds,
Beck smoothness is about 70 seconds. On top of this, bisphenol A 68° crystal violet lactone 2. A heat-sensitive coloring layer made of polyvinyl alcohol 30 dispersed in fine particles was coated to a thickness of about 5 μm and dried. This Bekk smoothness is approximately 100 seconds; if recorded as is, dropouts of approximately 40% will occur, resulting in image quality that is unsuitable for practical use.

The surface of this recording notebook was smoothed using a super calendar roll, and several kinds of notebooks with a maximum Bekk smoothness of about 10,000 seconds were prepared and recorded in the same manner. As a result, when the Bekk smoothness was up to about 1,000 seconds, dropout gradually decreased to 6%, but even when it reached an even smoother level of 10,000 seconds, dropout still occurred at about 2%. That is, unevenness remains on one back surface due to uneven density of the base paper.

On the other hand, on the back side of these recording sheets, particles with an average particle size of 0.1μ
A dispersion containing about 20% polyvinyl alcohol as a binder (solid content 36%) was applied to the fine clay of 200 m2 by dry weight to smooth the back surface and increase the C8 smoothness. recorded. As a result, even when the Bekk smoothness was about 600 seconds, when the GS smoothness was about 300 seconds, the dropout was less than 2%.

Therefore, if we look at the relationship between the S smoothness and dropout of the record sorting of the few points that we have prepared, we can see that the dropout decreases significantly when the GS smoothness is around 300 seconds.
When smoothed to about 1,000 seconds, almost no dropouts were observed, and high-quality images were obtained.

Example 2 For thermal transfer recording, wax type thermal transfer paper (manufactured by Fuji Kagaku Paper, capacitor paper type) was overlaid so that the coated surface was in contact with a separately prepared image receiving paper as a recording sheet with a thickness of approximately 60 μm. As in Example 1, it is inserted between the head and platen and recorded. Here, various types of image-receiving paper may be used with a coloring material adsorbent such as clay - or Example 1
Following the result of −(, after adjusting with S smoothness, G
Adjusting the S-smoothness to about 300 seconds significantly reduced dropouts - further smoothing to about 1,000 seconds gave a perfect image. However, even if only the Beck smoothness was increased to about 10,000 seconds, a dropout of several percent occurred.

On the other hand, as sublimation transfer recording, a-(a-N,N-dibenzylaminophenyl)-hyridine, which is a mono-yellow coloring leuco dye, was coated on one side of a 6 μm thick polyimide film in the same proportion by weight. Prepare a transfer saw + 4 coated with a sublimable dye layer of approximately 0-27 m2 consisting of 100 parts (manufactured by Tsuchiya Chemical Industry Co., Ltd.) and 30 parts of polysulfone as a binder.Additionally, an activated clay (proton donor) is coated on an image receiving paper as a recording sheet. material) to about 10 fi/(712
Prepare clay paper coated with high-quality paper (manufactured by Fuji Photo Film, Fuji Clay Paper 40 g/m2). These two sheets are overlapped so that their coated surfaces are aligned and recorded in the same manner as in Example 1.

Here, up to the clay paper t-, the GS smoothness is about 80
When the clay surface was supercalendered and the back surface was treated in the same manner as in Example 1 to increase the GS smoothness to about 300 seconds, an image with less dot D7 dropout was obtained. An image that seemed almost perfect was obtained with a Gs smoothness of about 1,000 seconds. Even in this ascending type example, it was not possible to obtain a high quality image by simply increasing the Bekk smoothness.

As can be seen from Examples 1 and 2 above, the usefulness of recording sheets with improved -GS smoothness is remarkable.

In addition, when similar effects were investigated by varying the hardness of the platen, relatively good images were obtained even with conventional recording sheets with increased Bekk smoothness in the range of hardness up to about 6o. However, when the recording sort of the present invention is used, high-quality images can be obtained from platens made of rubber materials having a hardness of 3 to 8 degrees to hard materials such as aluminum and brass.

In addition, although only examples using paper as the base material have been described as recording sheets, the gist of the present invention includes a wide range of materials other than paper, such as plastics and cellulose, and it is possible to maintain an appropriate range of GS smoothness regardless of the material. It is limited.

Furthermore, examples of coloring materials are not limited to the examples, but include materials that change color or emit a single color depending on the electrical signal of the recording head, and when using a thermal head, include ordinary sublimable dyes and thermochromy. It can also be applied to things.

The ability to provide such excellent recording sheets is due to the effect of the present invention, which succeeded in increasing the uniformity of sorting, which had been overlooked in the past. It can be adjusted based on the new idea of degree.

Next, a method for measuring GS smoothness will be explained with reference to the drawings.

In Fig. 1, 1 is the sample, 2 is the plane of the rigid body with gas through holes 3, 4 is the plane of the gas-shielding rigid body, arrow A represents the main direction and location of gas infiltration, and B is the gas discharge. Represents direction and location. This arrow B is an example of the through-hole negative pressure, and the pressure may be applied in the opposite direction.

A glass surface with an outer diameter of 37.5 mm and a circular hole with a diameter of 11.4 mm as a gas through hole was used as a rigid plane.A paper was placed on this, and the surface of a mirror-finished stainless steel plate with a diameter of 37.5 mm was placed on top of the rigid plane. It was used as a shielding rigid plane. While applying a load of 10 kg/r4 to the pair of parallel planes and pressing the sample, the gas through hole was opened to a depth of 300 mm.
The pressure was reduced to H9, and the air passage time of 10 ml was measured. The measurement results are shown in FIGS. 2 and 3 together with the conventional Beck method. Note that the parameters in the figure represent the uniformity of the sample, and are obtained by dividing the smoothness of this method by the conventional Beck value.

First, Fig. 2 shows a representative example using data for approximately 20 types of uncoated paper.No. 11 is glassine paper with a weight of 30 to 40 g/m2, No. 12 is base paper with a weight of 76 g/m2, and No. 13 is a base paper with a weight of 36 g/m2.
m2 wax paper base paper, 14 is 64g/m" printing paper,
15 is a fruit tree base paper with a thickness of 3.9/m'.

Fig. 3 shows data for about 20 types of coated paper.To explain typical examples, 21 is a synthetic paper with a thickness of about 60 μm, 22 is a synthetic paper with a thickness of 72~
75g/m1 fine coated paper, 23 is 1609/
m" high smooth clay paper, 24 is the back side of color photographic paper -
26 is a 29 oi/m2 white paperboard.

As is clear from these FIGS. 2 and 3, there is almost no correlation between the values obtained by this method and the Beck value, and it can be seen that the sheet used between rigid bodies cannot be evaluated based on Beck smoothness. Furthermore, the higher the uniformity evaluated using this method, the less uneven the sheet. The synthetic paper shown at 21 in FIG. 3 is a very uniform sorting material. On the other hand, the Granne paper shown in FIG. 2 11 has a uniform density due to calendering, but the uniformity is 0.1% because the original papermaking unevenness causes thickness unevenness. It has been reduced to o4 and is meaningless when used between one rigid body.

When these 40 types of samples were used as backing materials, a proportional relationship was established between the measured values of this method and the backing function.

On the other hand, bisphenol A was added to these samples at a fixed fraction ratio.
6B-Crystal Violet Lactone 2-Polyvinyl Alcohol A thermosensitive coloring layer having a composition of 30 was applied to a thickness of about 5 μm to prepare thermal paper.

When this thermal paper was wound around a smooth aluminum drum and recorded with a one-line thermal head, the higher the smoothness of this method, the better the image without unevenness was obtained.

Effects of the Invention As described above, according to the present invention, it is possible to provide recording sorting that can produce high-quality images without dropouts or unevenness, which could not be obtained even by specifying the conventional Beck smoothing method.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an apparatus for explaining the GS smoothness measurement method used in the present invention, Figure 2 is a diagram showing the smoothness of uncoated paper, and Figure 3 is a diagram showing the smoothness of various coated papers. FIG. Name of agent: Patent attorney Toshio Nakao and one other name
l Figure 2 Beck smoothing method wJ3 Figure Beck smoothing cliff (seconds)

Claims (4)

[Claims] (1) A recording sheet having a recording surface with a GS smoothness of 300 seconds or more. (2) The recording sort according to claim 1, wherein the recording surface has thermosensitive coloring properties. (3) Claim 1 in which the recording surface includes a coloring material adsorption material
Record sheet with section description. (4) The recording sort according to claim 1, wherein the recording surface has proton donor properties.