JPS62199498A - Eraser for erasing water-color ink - 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 (c) relates to a water-based ink erasing eraser for erasing handwriting drawn on water-based ink on non-penetrating surfaces such as tracing paper and matte processed films. It is.

(Conventional technology and its problems) Conventionally, with respect to water-based inks used for writing on non-permeable surfaces such as tracing paper and matte processed films, alkaline water was used as a binder for the ink in order to impart water resistance to handwriting. It is known that a melt-type resin is added.

As a method for erasing handwriting made with this type of water-based ink,
A type of eraser is known in which a solvent that can swell and dissolve the binder resin in the aqueous ink is contained in the eraser, and the eraser swells and dissolves handwriting as it is rubbed, thereby removing it.

However, according to this method, when rewriting is performed on the erased part of the handwriting, the tracing paper, which is the writing surface,
Depending on the film, there was a problem in that the handwriting that was rewritten would smudge.

The inventors of the present invention investigated the cause of handwriting smearing caused by rewriting, and found that the wettability of the film surface is good for water-based ink so that handwriting can be placed neatly on the film surface. However, after erasing handwriting, a small amount of solvent that swells and dissolves the binder resin in the water-based ink remains in the erased area, and the film surface, which is supposed to have good wettability, actually has poor wettability due to the remaining solvent. It was found that the water-based ink during re-writing spreads in all directions on the film, and as a result, the handwriting bleeds.

(Means for solving problems) The present invention was made in view of the above findings.

In order to prevent smearing caused by re-writing on erased areas, we conducted various studies on additives to the eraser, and found that an eraser containing a specific organic acid was effective, and we finally completed the process. It is something.

That is, the present invention provides an eraser for erasing water-based ink containing a solvent that swells or dissolves the binder resin of water-based ink, the eraser having a boiling point of 150°C or higher or a decomposition temperature of 150°C or higher, Moreover, the solubility of these is 0.1f/10” OP water (20℃)
The object of the present invention is to provide an eraser for erasing water-based ink, which is characterized by containing the above organic acid.

Two aspects of the present invention will be described in detail below.

Examples of the solvent for swelling or dissolving the binder resin in the aqueous ink of the present invention include ethylene glycol, diethylene glycol, triethylene glycol, and glopylene glycol.

Examples include glycols such as dipropylene glycol. These solvents are used alone or in a mixture of two or more, and the amount used is 5 to 50% based on the total weight of the eraser.
% by weight, preferably 5 to 30% by weight.

The organic acid that functions as a smear-preventing agent, which is a feature of the present invention, can be used dissolved in the above-mentioned solvent or directly added to the eraser base material to erase handwriting. After that, a small amount of this organic acid remains on the film together with the solvent. Therefore, basically, when a new water-based ink comes into contact with the area where handwriting has been erased, the remaining organic acid dissolves into this ink and makes the ink acidic, so that the alkaline water in the ink at that area is absorbed. It is thought that the molten resin precipitates and the ink thickens, and as a result, the handwriting does not spread in all directions when rewritten, and bleeding is prevented.

Therefore, this organic acid must be dissolved quickly in the water-based ink, so the organic acid must be dissolved quickly in the water-based ink. Solubility in is 0.17
(20°C) or higher. This is because if the solubility is less than 0.1, handwriting may bleed when rewritten. Furthermore, this organic acid needs to have a boiling point of 150°C or higher or a decomposition temperature of 150°C or higher. This is because when actually obtaining an eraser, the molding temperature is approximately 11
If the boiling point or decomposition temperature conditions described above are not met, the organic acid will evaporate or decompose due to the relatively small amount added, making it impossible to achieve the intended purpose. This is because. Therefore, examples of organic acids that can satisfy these conditions include the following.

Sokuthi, cyclohexanecarboxylic acid, cono-phosphoric acid.

Adipic acid, benzoic acid, etc. are organic acids that evaporate before being decomposed, so they are identified by their boiling points.

Citric acid is a type of organic acid that decomposes itself before it evaporates, so it is specified by its decomposition temperature. In particular, as shown in the table above, citric acid has an extremely high solubility, and its solubility in water-based inks is also extremely good.

Therefore, the water-based ink becomes acidic in a short period of time, which is very advantageous in preventing handwriting from smearing when rewriting. The above organic acids may be used alone or in an appropriate mixture of two or more, and the amount used is as follows.

The amount is 1 to 20% by weight, preferably 5 to 15% by weight, based on the amount of solvent that swells or dissolves the binder resin in the aqueous ink.

Next, the method for manufacturing the eraser of the present invention will be described.

There are various methods for actually incorporating into the eraser a solvent that swells or dissolves the organic acid and the binder resin of the aqueous ink, but two typical examples will be described below. That is.

■ After gelling the plasticizer with a gelling agent, this is mixed with an organic acid, a solvent, and a conventionally known eraser base material, particularly preferably polyvinyl chloride or a copolymer of polyvinyl chloride and polyvinyl acetate. A method to obtain an eraser by adding a stabilizer and uniformly dispersing and mixing it to form a paste, which is then heated and molded.

■After adding a plasticizer and a stabilizer to the above-mentioned eraser base material to form a paste, powder method microcapsules containing an organic acid and a solvent as core materials are added and uniformly stirred and dispersed.
This is then heated and molded to obtain an eraser.

It is.

Accordingly, in the present invention, the desired eraser is obtained by two or more methods, and the organic acid may be dissolved in a solvent as appropriate, and various fillers and fragrances may be added as necessary. It goes without saying that superabsorbent polymer substances and the like may be added.

(Example) The present invention will be explained in more detail below based on two examples.

Example 1 150 parts by weight of dioctyl phthalate (plasticizer) (hereinafter referred to as
It is simply expressed as "part." ) was added with 5 parts of a gelling agent (Gel All D, manufactured by Shin Nippon Rika ■), heated and dissolved, and then allowed to cool to obtain 155 parts of a gelled plasticizer. Add 55 parts of diethylene glycol to this gelled product.

・Polyvinyl chloride/' (G e o n 121.

Nippon Zeon ■) 150 parts epoxidized soybean oil (stabilizer) 3 parts calcium carbonate
Add 30 parts of cyclohexanecarboxylic acid and 6 parts of cyclohexanecarboxylic acid, stir and mix evenly, and add 11 parts of cyclohexane carboxylic acid.
Press molding was performed at 0°C for 220 minutes to obtain an eraser.

Example 2 <Production method of powder bed microcapsules> 7 parts of citric acid was dissolved in 70 parts of propylene glycol,
45 parts of calcium carbonate were mixed with stirring to obtain 122 parts of a paste-like product. This was then stirred at high speed in 20 parts of ultrafine silica powder to obtain 142 parts of silica-walled microcapsules.

Manufacturing method of eraser - Polyvinyl chloride (Geon 121゜Nippon Zeon ■
) 150 parts dioctyl phthalate (
Plasticizer) 150 parts/Epoxidized soybean oil (stabilizer)
3 parts of the above valve were stirred and mixed to obtain 303 parts of a paste-like material, and the above-mentioned microcapsules 142 were added to this paste-like material.
After stirring and mixing, press molding was performed at 110''C for 20 minutes to obtain an eraser.

Comparative Examples 1 and 2 Comparative Examples 1 and 2 were prepared in the same manner as in Examples 1 and 2, except that the organic acids were removed, respectively.
And so.

(Effect) Film (B15hop Graphics In
Water-based pigment ink (manufactured by Rotring F)
, Rotring Exhibition) were rubbed and erased using the erasers obtained in Examples 1 and 2 and Comparative Examples 1 and 2, respectively.
After that, when the same ink was used to rewrite the erased handwriting, no smearing of the handwriting was observed when using the eraser of Example 1.2, and when using the eraser of Comparative Examples 1 and 2, no bleeding was observed. Smudged handwriting was visible.

As described above, according to the water-based ink erasing eraser of the present invention,
This is extremely advantageous in practice because it can prevent blurring when rewriting at the erased handwriting location as much as possible.

Claims (1)

[Claims] In an eraser for erasing water-based ink containing a solvent that swells or dissolves the binder resin of water-based ink, the eraser has a boiling point of 150°C or higher, or a decomposition temperature of 150°C or higher, and the solubility of these solvents. An eraser for erasing water-based ink, characterized in that it contains an organic acid having a ratio of 0.1 g/100 g water (20° C.) or more.