JPS58134799A - Eraser - 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 The present invention relates to an eraser used to erase handwriting drawn on the surface of a drafting film using a writing instrument using ballpoint pen ink for drafting, oil-based ink, or film core material. To provide an eraser that can be easily used even in areas with complicated handwriting and does not leave any erased marks.

When erasing handwriting drawn on the surface of a drafting film using ballpoint pen ink for drafting, oil-based ink, or writing instruments that use core material for film, use a bleaching liquid or organic solvent to wipe it off. There are two types of erasers: one is a sand letter eraser, and the other is an eraser for scraping off, which is generally referred to as a sand letter eraser, but the former is difficult to operate when erasing only a part of a complex handwriting, and may cause erased marks to bleed onto the film surface. The latter method has drawbacks such as being unable to leave clean eraser marks, and the latter being unable to prevent scars from remaining on the film surface.

The present invention, as set forth in the claims, not only erases handwriting using a normal pencil lead, but also eliminates all of the drawbacks of the conventional eraser as described above, and in particular, uses ballpoint pen ink for drafting, With oil-based ink or a writing instrument that uses film core material, you can erase handwriting drawn on the film surface without leaving any scratches or oozing marks on the film surface, even if the desired area is complex. To provide an eraser that can easily erase even a handwriting consisting of only a part of it.

The structure of the eraser of the present invention will be explained below.

The eraser of the present invention is characterized by its composition, and is composed of a polyvinyl chloride resin, a plasticizer for the polyvinyl chloride resin, an organic solvent with a boiling point of 200°C or higher, and an inorganic filler. , and the boiling point mentioned above is 200
The organic solvent having a temperature of 0.degree. C. or higher has a dissolving action on the synthetic resin that is the binder used in ballpoint pen ink for drafting, oil-based ink, or film core material.

It is preferable that the plasticizer for the polyvinyl chloride resin in the composition components constituting the eraser of the present invention and the organic solvent with a boiling point of 200° C. or higher have compatibility. Below, benzoic acid esters such as Benzoflex and phosphoric acid esters such as tricresyl phosphate are used, but according to experimental results, Benzoflex, a benzoic acid ester, is most suitable. Organic solvents with a boiling point of 200° C. or higher, which are characterized by their volatility over time, include, for example, benzyl alcohol, nitrobenzene, and acetamide.

Hexamethyl phosphate triamide, triethyl phosphate, ethylene carbonate, propylene carbonate, etc.
Most preferably propylene carbonate is used.

The composition components in the eraser of the present invention generally include 40 to 50% by weight of polyvinyl chloride resin, 25 to 35% by weight of plasticizer based on the polyvinyl chloride resin, and a boiling point of 200°C.
It is composed of a mixture consisting of about 15 to 30% by weight of the above organic solvent, and an appropriate amount of an inorganic filler such as calcium carbonate, magnesium carbonate, clay, alumina, titanium oxide, and light calcium carbonate.

This is obtained when the amount of polyvinyl chloride resin is less than 1+0% by weight based on a mixture consisting of polyvinyl chloride resin, a plasticizer for the polyvinyl chloride resin, and an organic solvent with a boiling point of 200°C or higher. Not only will the eraser become too soft and sticky, but it will also leave white erased marks on the film surface, making it uncomfortable to use.
If it exceeds 0% by weight, the resulting eraser will become too hard, resulting in disadvantages such as reduced erasing performance and poor usability. Furthermore, if the amount of plasticizer relative to the polyvinyl chloride resin is less than 25% by weight, the gelation of the vinyl chloride resin in the resulting eraser will not be sufficient, making the eraser brittle and easy to crumble during use, resulting in a large amount of eraser scum. If this becomes significant, problems such as loss of mechanical strength and collapse may occur. If it exceeds 35% by weight, the resulting eraser will become too soft and sticky. Furthermore, an organic solvent with a boiling point of 200°C or higher is
If it is less than 5% by weight, the erasing performance of the resulting eraser will deteriorate and handwriting will not be erased sufficiently, and if it exceeds 30% by weight, the vinyl chloride resin in the composition will be dissolved and the viscosity of the paste will increase. As a result, thixotropy occurs, resulting in an unstable eraser.

The inorganic filler, most preferably light calcium carbonate, is about 10% by weight of the mixture consisting of the polyvinyl chloride resin, a plasticizer for the polyvinyl chloride resin, and an organic solvent with a boiling point of 200° C. or higher. Added or contained.

The eraser of the present invention is composed of the compositional components as described above, and is a normal plastic rubber type, so it is easy to operate even when erasing only a part of complicated handwriting. In addition to handwriting with regular pencil lead, there are also oozes that remain on the film surface when wiped with a bleaching liquid or organic solvent, and bleeds that remain on the film surface when erased with a sand eraser. It has the function and effect of being able to erase handwriting drawn with ballpoint pen ink for drafting, oil-based ink, or writing instruments using film core material, without leaving any scratches or the like on the film surface. play. □ In addition, in the eraser of the present invention, when a plasticizer for vinyl chloride resin and an organic solvent with a boiling point of 200°C or higher are used, it is possible to Due to the volatility of the solvent over time, the phenomenon of liquid bleeding or volatilization on the surface of the resulting eraser is suppressed, so in the case of polyvinyl chloride resin erasers mixed with conventional solvents. This makes it possible to use a molding composition containing plasticizers and solvents directly, without requiring operations such as microencapsulation of solvents or adsorption to powder, which were required for molding. Not only is the manufacturing process simple, but it also has the effect of producing an eraser that is highly stable during use.

Hereinafter, the configuration of the eraser of the present invention will be described as a manufacturing example, 1:]
1 will be explained.

Examples Two types of mixtures having the composition ratios shown in A and B in Table 1 below are thoroughly mixed in a mixer, then poured into a mold, heated at 100°C for 15 minutes, and pressurized to form a plastic rubber. Type eraser (1), (I[)
It's wo 4.

Table 1 Table 2 shows the usability of the commercially available eraser and the two types of erasers (1) and (II) obtained in the above examples, as well as the results of the erasing test.

The eraser of the present invention obtained in the above example can be used not only for handwriting drawn with a regular pencil on a sheet of paper, but also for writing with an oil-based ballpoint pen on a Mylar film surface.

To erase handwriting drawn with a writing instrument using a film core material or an oil-based marker writing instrument, etc., without leaving any traces, with a simple operation similar to erasing handwriting drawn with a regular pencil on paper. It is of great practical value, especially when correcting mechanical drawings drawn with a ballpoint pen or handwriting on an oil-based felt-tip pen for an overhead blogger.

, 19 Patent applicant: Mitsubishi Pencil Co., Ltd. Agent: Osamu Ichikawa, Ichiyoshi Yoshiarai
Kiyoko

Claims (1)

[Claims] The composition components are polyvinyl chloride resin, plasticizer, and boiling point 2.
An eraser made of an organic solvent at 00°C or higher and an inorganic filler, where the organic solvent has a dissolving effect on ballpoint pen ink for drafting, oil-based ink, or synthetic resin as a binder in the core material for film. An eraser with one characteristic.