JPS59115899A - Heat sensitive screen printing stencil paper - Google Patents

Abstract

PURPOSE:To provide heat sensitive screen printing stencil paper for imparing sharp printed matter stable with the elapse of time, obtained by laminating a polyester film with a specific thickness to a porous support based on a synthetic fiber by an adhesive based on methoxymethylated polyamide resin. CONSTITUTION:In screen printing stencil paper prepared by laminating a thermoplastic synthetic resin film to a porous support with an adhesive and capable of being drilled by infrared rays, as the thermoplastic synthetic resin film, a polyester film with a thickness of 5mum or less is used while, as the porous support, a support based on a synthetic fiber with a size of 0.5-1.5 denier such as a polyester fiber, a Vinylon fiber or a nylon fiber is used and both of them are laminated with an adhesive based on methoxymethylated polyamide resin. The impregnating ratio of the adhesive to the porous support is pref. 60% or less.

Description

[Detailed description of the invention] Alternatively, by superimposing characters, figures, etc. on a roasted original and irradiating it with infrared rays, the parts of the original corresponding to the characters and figures absorb the infrared rays and melt due to the generated heat. The present invention relates to a heat-sensitive stencil paper which is perforated to give a stencil.

Conventionally, heat-sensitive stencil paper has been produced by laminating vinyl synthetic resin films such as vinylidene chloride-vinyl chloride copolymer resin films and polypropylene films with porous thin paper made from natural fibers such as paper mulberry, Japanese mulberry, and Manila hemp using adhesives. (For example, see Japanese Patent Publication No. 41-7/) 23 and Japanese Patent Publication No. 47-17336).

However, porous tissue paper made from natural fibers is extremely sensitive to humidity; for example, when humidity is high, its strength decreases and its elongation slows down, while when humidity is low, it maintains high strength but shrinks. Vinyl synthetic resin films that are laminated ten thousand times are easily affected by temperature, but are less affected by humidity. In this way, porous tissue paper and vinyl-based synthetic resin film are sensitive to humidity.

The degree of influence varies depending on external conditions such as temperature, and this poses a problem in that adhesive strength decreases during storage.

Furthermore, although vinyl-based synthetic resin films with a thickness of 6 μm or more are used, such thick films have poor perforation properties with infrared rays, making it difficult to reproduce stencils that are faithful to the text, graphics, etc. of the manuscript. There is.

In order to solve the above problem, for example, the amount of adhesive used for lamination may be adjusted (see Japanese Patent Publication No. 1187-1987),
Porous thin paper made by mixing some chemical fibers with natural fibers is used (see Japanese Patent Publication No. 4B-8217),
It has been proposed to impregnate the entire porous thin paper with a synthetic resin (see Japanese Patent Publication No. 55-47997), but nothing satisfactory has yet been achieved. For example, if the entire porous tissue paper is impregnated with synthetic resin, the influence of humidity will be reduced, but because the amount of synthetic resin impregnated is large, the permeability of printing ink will deteriorate, and the print clarity will actually decrease. There's a problem.

However, the inventors of the present invention have conducted intensive research to improve the above-mentioned drawbacks of conventional heat-sensitive stencil paper, and as a result, the degree of influence of the applied film and porous support on the external conditions has been made as close as possible, and By bonding them together with a specific adhesive, he discovered that it was possible to replace heat-sensitive stencil paper that was stable over time and produced clear printed matter, and was able to complete his invention.

That is, the present invention provides a stencil paper that can be perforated by infrared rays and is made by bonding a thermoplastic synthetic resin film to a porous support with an adhesive. Using a porous support whose main component is synthetic fiber,
The present invention relates to a heat-sensitive stencil paper, characterized in that the polyester film and the porous support are bonded together using an adhesive containing a methoxymethylated polyamide resin as a main component.

In the present invention, a porous support whose main component is synthetic fiber is used, and the degree of influence of external conditions such as temperature and humidity on this porous support and the polyester film laminated thereon is approximately the same. By bonding these together using a special adhesive featuring methoxymethylated polyamide resin, a large amount of adhesive strength can be achieved with a small amount of adhesive, and it does not deteriorate over time. . Therefore, by making a stencil using infrared rays, it is possible to create a stencil that is faithful to the original, and when printing a large number of sheets, there is no risk that the film in the holes of the stencil will peel off or fall off, making it possible to print a large number of extremely clear prints. .

In addition, since the polyester film used in the invention is thin, with a thickness of 5 μm or less, it has excellent perforation properties, and as a result, it is possible to reproduce stencils that are faithful to the characters, figures, etc. of the manuscript, and to reproduce printed matter with excellent printing clarity and resolution.

Furthermore, in the present invention, by using a specific porous support and film as described above and using a specific adhesive, the porous support and the polyester film can be firmly bonded even if the amount of adhesive used is small. In heat-sensitive stencil paper, the smaller the amount of adhesive impregnated into the porous support, the better the printing clarity and resolution, so it is possible to reduce the amount of adhesive used and impregnate the porous support with adhesive. The invention of reducing the amount as much as possible is extremely advantageous in this respect.

The polyester film used in the present invention has a thickness of 5μ or less, preferably 1 to 5μ, more preferably 1
．． It has a diameter of 5 to 3μ. If the thickness exceeds the above range, the infrared ray perforation will be poor and it will be difficult to create a stencil that is faithful to the original. If the thickness is less than the above-mentioned range, the strength will be low and μ will pass through, which is not preferable. A biaxially stretched film is usually used as the polyester film, and preferably has a stretching ratio of 150 to 250% in the longitudinal and transverse directions.

The porous support used in the present invention is made from fibers mainly composed of synthetic fibers such as polyester, vinylon, and nylon fibers with a fineness of 3 denier or less, preferably 0.5 to 1.5 denier.

Natural fibers such as manila hemp, mulberry, mitsumata, pulp, etc. may be mixed with the synthetic fibers, but in that case, the proportion is 30 parts or less based on 100 parts (parts by weight, the same shall apply hereinafter) of all fibers. It is preferable to use The porous support preferably has a basis weight of 6 to 141/m'' and a thickness of about 20 to 60 μm.

The adhesive used in the invention has a methoxymethylated polyamide resin as its main component. This methoxymethylated polyamide resin is a polyamide resin in which the hydrogen atoms of N-H groups in the amide bonds are partially substituted with methoxymethyl groups, and the substitution rate of methoxymethyl groups is 25 to 3.
3 mol% is used.

The heat-sensitive stencil paper of the present invention is prepared by drying an adhesive solution obtained by dissolving methoxymethylated polyamide resin in a suitable solvent such as methanol, ethanol, isopropyl alcohol, etc. to a concentration of about 5 to 30% by weight on the polyester film. It can be obtained by applying the coating at a coating amount of 0.5 to 2 f/m, overlaying the porous support thereon, and drying at a temperature of 80 to 10,080 culm degrees. If the dry coating amount of the adhesive is less than the above range, the adhesive strength will be reduced, and if it is more than the above range, the printing clarity will be extremely reduced, which is not preferable. Furthermore, as mentioned above, the porous support used in the present invention is affected by external conditions such as humidity almost the same as the polyester film to which it is laminated, so there is no particular need to impregnate it with an adhesive; rather, it is impregnated with a large amount. Doing so is not preferable because it results in a loss of print clarity. From this point of view, the impregnation rate of the adhesive into the porous support (referring to the percentage of the depth at which the adhesive is impregnated from the surface of the porous support on the polyester film side to the total thickness of the porous support) is 60% or less, Nakanzu <4
It is preferably 0% or less. Therefore, the method of superimposing a polyester film and a porous support, applying an adhesive from the porous support side, impregnating it, and adhering it is such that the entire thickness of the porous support is impregnated with the adhesive, and the printing is clear. It is not desirable because it impairs the sex.

The present invention will now be described with reference to Examples and Comparative Examples.

Example 1 Methoxymethylated polyamide resin (methoxymethylation rate 60 mol%) 1 was added to a biaxially stretched polyester film (stretching ratio is approximately 200% in both the longitudinal and transverse directions) with a thickness of 6 μm.
An adhesive solution consisting of 0 parts, 60 parts of methanol, and 30 parts of isopropyl alcohol was applied in a dry coating amount of 1.0 gl.
A porous support with a basis weight of 9.89/m2 and a thickness of 35μ obtained by mixing 80 parts of polyester fiber and 20 parts of manila hemp was superimposed on it, and a porous support of 85° A heat-sensitive stencil paper was obtained by heating and drying at 0.0. The impregnation rate of the adhesive into the porous support was 45%.The impregnation rate was measured by laminating as described above using a colored adhesive.
It was determined from the cross-sectional photograph.

The heat-sensitive stencil paper was superimposed on the manuscript,
As a result of perforation plate making using a side leg Lingraph Fax model 7200 thermal plate making machine and printing using a Gess 420W rotary press manufactured by Gestelatner, 600 sheets of extremely clear printed matter were obtained.

Example 2 Methoxymethylated polyamide resin (methoxymethylation rate 31%) 1 was applied to a biaxially stretched polyester film with a thickness of 3.3 μm (stretching rate is approximately 200% in both the longitudinal and transverse directions).
An adhesive solution consisting of 4 parts of ethyl alcohol, 60 parts of isopropyl alcohol, and 16 parts of water was applied so that the dry coating amount was i, 2 p/m2, and on top of that, 75 parts of vinylon fiber and 25 parts of Manila hemp were mixed. The obtained porous supports with a basis weight of 10.5 f/rn" and a thickness of 40 μm were stacked and dried by heating at 95°a to obtain a heat-sensitive stencil paper. Applying the adhesive to the porous support The impregnation rate was 33%.

Using the heat-sensitive stencil paper, plate making and printing were carried out in the same manner as in Example 1, resulting in 400 extremely clear printed matter.
I got 0 pieces.

Furthermore, after the heat-sensitive stencil papers obtained in Examples 1 and 2 were left for 90 days at 50° and 0.60% RH, the adhesive strength and printing clarity between the polyester film and the porous support were as follows. It was the same as immediately after manufacturing, and no changes were observed.

Example 1 Same as Example 1 except that an adhesive solution consisting of 10 parts of vinyl acetate resin, 10 parts of methanol and 30 parts of ethyl acetate was used as the adhesive for bonding the polyester film and the porous support in Example 1. A heat-sensitive stencil paper was prepared in the same manner, and plate making and printing were carried out in the same manner as in Example 1 using this.

As a result, in the case of characters and figures in the manuscript whose outlines are continuous, such as characters and figures such as ○, mouth, country, etc., when printing, the characters and figures on the stencil are printed within the continuous outline of the characters and figures. Because the film was removed, all I could get was letters and figures that looked like ., ■, and ■, which were completely filled in.

Further, after the heat-sensitive stencil paper was left for 90 days at 50° and 0.60% RH, the adhesive strength between the polyester film and the porous support had decreased to about 80% of that immediately after production.

Comparative Example 2 On top of the same polyester film used in Example 1, a porous support with a basis weight of 9.897 m2 and a thickness of 35 μ, obtained by mixing 80 parts of Manila hemp and 20 parts of polyester fiber, was layered. The same adhesive solution used in Comparative Example 1 was applied from the side of the porous support so that the dry coating amount was 6.097 m2, impregnated, and then dried to obtain a heat-sensitive stencil paper.

When this heat-sensitive stencil paper was used for plate making and printing in the same manner as in Example 1, the print clarity was lower than in Examples 1 and 2, and in particular, small characters of size 5 or smaller were unclear. there were.

Claims (1)

[Scope of Claims] 1. In a stencil paper that can be perforated by infrared rays and is made by laminating a thermoplastic synthetic resin film to a porous support with an adhesive, a polyester film with a thickness of 5 μm or less is used as the thermoplastic synthetic resin film, A porous support mainly composed of synthetic fibers is used as the porous support, and the polyester film and the porous support are bonded together with an adhesive mainly composed of methoxymethylated polyamide resin. Heat-sensitive stencil paper. 2. The heat-sensitive stencil paper according to claim 1, wherein the impregnation rate of the adhesive into the porous support is 60% or less.