JPS6063195A - Recording material - Google Patents

Abstract

PURPOSE:To provide a recording paper having uniform thickness, free of curling and capable of producing a stable image with favorable quality, wherein a paper having a specified basis weight and a specified sizing degree is used as a base, and a water base coating material is applied thereto. CONSTITUTION:A paper having a basis weight of 50-80g/m<2>, a sizing degree of 5-100sec and preferably having a thickness of 60-100mum is used as a base, and a water base coating material containing PVA, a cellulose derivative or the like is applied thereto to obtain the objective recording paper. USE:Recording papers for printers, plotters facsimiles or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording medium used for directly recording information as a visible image, that is, recording paper.

With the recent development of printers, plotters, facsimiles, etc., thermal paper is used to directly record information as a visible image. There is a great demand for recording paper, which is so-called coated paper.

However, regarding such recording paper, this is the so-called
Because it is a specially processed paper, it is often pointed out that it lacks the feel of plain paper.

These defects are often partially due to uneven thickness or thinness of the coating film or irregularities on the surface of the coating film in conventional recording paper. In addition, in terms of recording performance, if the thermal recording paper has uneven thickness or unevenness, uneven heat conduction (in extreme cases, no heat is applied) will occur, making it impossible to obtain an image that is faithful to the input information. The uneven thickness of the coating film on paper causes variations in the volume resistance of the recording paper, and the unevenness of the surface causes variations in the contact resistance between the stylus and the surface of the recording paper. As a result, the impedance of the entire system during recording will fluctuate irregularly, causing not only unevenness in image density but also, in severe cases, current not flowing in a steady state and sparks occurring, causing the image to deteriorate. Phenomena such as discharge destruction, image roughness, and reduction in image sharpness have been observed.

SUMMARY OF THE INVENTION In view of the conventional drawbacks, the present invention aims to provide a recording medium that consistently records high-quality images in a stable manner and has a feel similar to that of plain paper. be. The present invention, which achieves the above objects, is, in short, a recording medium characterized by having a moon as a support.

The above-mentioned thermal recording paper or electric recording paper is made of predetermined image forming components and a water-soluble binder such as polyvinyl alcohol, cellulose derivative, polyacrylamide, starch (and a conductive agent is added as necessary). It is obtained by coating a support such as paper with a water-based paint containing the following. Further, in order to maintain a good feel of the recording medium, plain paper is generally used as the support. Conventionally, when manufacturing such recording media, the water-based paint dries on the paper support, causing unevenness on the surface of the recording material, curling of the recording material, and even the water-based paint drying on the paper. It has often been experienced that the coating is not applied uniformly, causing problems such as minute unevenness in the coating film. Based on the results of numerous studies, the present inventors have found that the above-mentioned disadvantages can be overcome by adjusting the characteristics of the paper used as the support. That is, it has been found that the basis weight and size of the paper serving as the support are particularly important factors.

First, the basis weight indicates the weight of the paper, but it is also related to the thickness of the paper or the density of the paper fibers. Paper basis weight is 50g/
If it is less than m2, the applied water-based paint will pass through more and the coated film after drying will tend to have uneven thickness. Moreover, if the basis weight exceeds 80 g/m2, the paper thickness increases, which impairs the feel and is not preferable in recording operations. The basis weight of such paper can be measured according to JIS P8110 and JIS P8111, and the above standard method was also followed in the present invention.

On the other hand, sizing is a value representing the paper's resistance to liquid wetting. Based on this, in the present invention, it is possible to know the degree to which the water-based paint permeates into the paper. If the sizing rate is less than 5 seconds, even the binder in the paint will seep into the paper, causing the coated paper to swell and, after drying, to create corrugations and unevenness on the recording paper. On the other hand, if the sizing degree exceeds 100 seconds, the paint hardly passes through, causing peeling of the paint film, causing part of the paint film to be missing, or causing the recording paper to curl when drying. The size degree in this invention is JIS standard, P8
This value is based on the test method specified in 122.

As mentioned above, the present inventors have determined that the paper used as the support has a basis weight of 50 to 80 g/m2 and a size degree of 5 to 100.
It has been found that papers in the range of seconds are suitable. Furthermore, in addition to the above-mentioned conditions, the paper thickness is preferably in the range of 60 to i00=. Paper with a paper thickness of 60 W or less is so-called weak and inconvenient to handle, and paper with a paper thickness of 100 #L or more feels thick and loses its feel as a recording paper.

Hereinafter, the present invention will be explained in more detail with reference to Examples. Further, the effects of the present invention will also be illustrated by application examples. In addition, the parts shown in the examples are parts by weight unless otherwise specified.

Example 1 Thoroughly pole mill the above to obtain liquid A.

Thoroughly pole mill the above to obtain liquid B. Next, 10 parts of the above liquid A, 50 parts of liquid B, and 100 parts of water were mixed, and this was used as a coating. On the other hand, a high-quality paper with a size of 52 g/m2, a size of 12 seconds, and a paper thickness of 65 gc7) was prepared as a base paper, and the above paint was applied to it using a coating rod so that the coating film thickness was 5 tiles. . It was further dried to obtain recording paper. Such recording paper had an even coating film thickness and no curling.

Example 1 of Example 1 The recording paper of Example 1 was calendered to obtain a coating surface smoothness of 1000 seconds (Beck smoothness), and then printed using a thermal printer [...product name: Canola 5X10].
3 (to Cannon, K.

When printing was carried out using the attached heat-sensitive recording device (manufactured by the manufacturer), an extremely clear image with no uneven printing was obtained. The recording paper did not curl even after the recording operation, and had a good feel as paper.

Example 2 With the basis weight (55 g/L2) and thickness 70 L constant, various types of paper with different sizes as shown in the table below were prepared as base paper, and the same paint as in Example 1 was applied to each paper in the same manner. I coated it and made recording paper.

Incidentally, in sample No. 2-1, waviness was observed on the entire surface, and in sample No. 2-8 and sample No. 2-9, many missing parts of the coating film were observed.

Application Example 2 Using each sample in the table shown in Example 2, printing operations similar to those in Example 1 were performed. After recording, the magnitude of density unevenness in the image (color development) for each sample was measured.

The value of image density unevenness in the above table is the difference between the maximum density part and the minimum density part of the colored image, and the density was measured using a Macbeth reflectance scale (using a green filter).

Example 3 100 parts of a 15% lithium chloride aqueous solution was added to 10 parts of liquid A and 50 parts of liquid B prepared in Example 1 above and mixed to prepare a paint.

Separately, basis weight 60 g/m2, size degree 20 seconds, paper thickness 7
A 3#L high-quality paper was prepared as a base paper, and the above paint was coated on it using a coating rod so that a coating film of 8 pots was formed.Then, this was dried to obtain a recording paper. No unevenness in coating film thickness or missing parts were observed on such recording paper.
No curling occurred either.

Application example 3 An aluminum plate was brought into contact with the base paper side of the recording paper obtained in Example 3, a 0.2 mm diameter tungsten needle was placed on the coating film, and a DC voltage of 500 V was applied between the two in pulses of 100 g 5 ec. A colored mark of a size corresponding to the diameter of the needle was obtained. Also, I continued the recording operation while scanning the needle, but
The movement of the needle was extremely smooth, and no density unevenness was observed in the colored marks.

Example 4 The size degree (12 seconds) and thickness (70 l and 85 l) were kept constant, and various papers with different basis weights as shown in the table below were prepared as base paper, and the paints prepared in Example 3 were respectively prepared. was coated in the same manner as in Example 3 to prepare recording paper.

In addition, many coating film unevenness was observed in the recording paper of sample No. 4-1, and sample No. 4-8 and No. 4-9
The recording paper was poor in terms of feel.

Application Example 4 For each sample of Example 4, energization recording was performed in the same manner as Application Example 3. After recording, the magnitude of density unevenness of the colored mark was measured for each sample. The value of density unevenness of colored marks in the table shown in Example 4 is the difference between the maximum density part and the minimum density part, and the density is measured with a Macbeth reflection densitometer (using a green filter).

Applicant Canon Co., Ltd.

Claims (1)

[Scope of Claims] A recording material characterized by being formed by applying a water-based paint to a piece of paper. (2) The recording medium according to claim 1, wherein the thickness of the paper is in the range of 60i to 100g.