JP2601704B2 - Eraser for correcting electrostatic copy images - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eraser for correcting an image formed by an electrostatic copying method, and more particularly to an eraser for correcting an electrostatic copied image formed on plain paper. The present invention relates to an eraser suitable for use in the present invention.

(Prior art and its problems) Generally, the surface of paper has irregularities due to folding of paper fibers, and an image obtained by the electrostatic copying method is composed of a colored synthetic resin powder called toner which is dissolved and fixed. Therefore, even though the toner does not penetrate into the paper fiber itself, it penetrates into the concave portion of the paper fiber and is fixed, so that it cannot be completely erased by an ordinary eraser for a pencil.

Therefore, conventionally, in order to erase these images, a method of mainly shaving off a portion to be erased with a blade of a cutter knife or a method of rubbing and erasing the portion with an abrasive containing an abrasive called a sand eraser has been adopted. However, according to these, it is troublesome, and it is necessary to quickly rub the paper surface with force, resulting in poor workability. Further, peeling off the fibers on the paper surface damages the paper surface, causing another problem such as making the appearance inferior and making rewriting impossible.

In recent years, in order to increase workability and speed of rubbing the paper surface and improve erasing ability, an eraser is fixed on the extension of the rotating shaft of the motor, and the eraser is rotated by rotation of the motor, and the rotation is performed. An electric eraser that erases paper by bringing an eraser into contact with paper has appeared.

However, even if this eraser is used, it cannot be erased with a pencil eraser, and of course, when a sand eraser is used, there is a problem that the paper is severely damaged and the paper is broken.

(Means for Solving the Problems) In view of the above problems, the present inventors have finally completed the present invention as a result of intensive studies. That is, the gist of the present invention is that the hardness (Hs, JIS K6301) is 70 or more and 95 or more. Below, tensile strength (JIS
K6301) comprising at least a thermoplastic elastomer resin of not less than 250 kg / cm ^{2 and not} more than 500 kg / cm ² .

 Hereinafter, the present invention will be described in detail.

Thermoplastic elastomer is a polymer material that exhibits the properties of vulcanized rubber at normal temperature but is plasticized at high temperature and can be molded with a normal plastic processing machine. A rubber component (soft segment) having elasticity in the molecule, It has both molecular constraint components (hard segments) that prevent plastic deformation.
Thermoplastic elastomers can be broadly classified into styrene, olefin, ester, and urethane types.To obtain an eraser that can erase an electrostatic copy image, the toner that has been melt-fixed to the paper must be peeled off from the paper. The resin must have sufficient strength. For this reason, a resin having a hardness of less than 70 (Hs, JIS K6301) is too soft, so that the toner forming the electrostatic copy image cannot be scraped off. Conversely, if the resin has a hardness of more than 95, it will be too hard, and although the toner can be scraped off, the paper fibers will also be scraped and the paper will be damaged.

Even if the resin has a hardness of 70 or more and 95 or less, if the tensile strength (JIS K6301) is less than 250 kg / cm ² , the eraser itself will be worn before the rubbing force is sufficiently transmitted to the toner to be erased. And the image cannot be erased.
On the other hand, if the weight exceeds 500 kg / cm ² , the eraser becomes too strong, and the paper is damaged and no eraser dust is produced. Therefore, in order to erase an electrostatic copy image, the hardness is
70 or more 95 or less, the tensile strength must be used a thermoplastic elastomer is 250 kg / cm ² or more 500 kg / cm ² or less. Specific examples of such thermoplastic elastomers include Kraton G1650 (hardness 75, tensile strength 352 kg / c
m ² ), G1652 (hardness 75, tensile strength 316 kg / cm ² )
Shell Chemical Co., Ltd.), Tufprene T-414 (hardness 90, tensile strength 300 kg / cm ² ) (Asahi Kasei Kogyo Co., Ltd.), Elastran E180 (hardness 80, tensile strength 380 kg / cm ² ), E190
(Hardness 90, tensile strength 400 kg / cm ² ), E980 (hardness 80, tensile strength 450 kg / cm ² ), Royal Sen R380 (hardness 83, tensile strength 300 kg / cm ² ) (Nippon Elastollan Co., Ltd.)
Manufactured). In order to further enhance the performance, it is preferable to rotate the eraser at a portion to be erased and erase the image with the rotational force. Specifically, there is the above-described electric eraser.

In the present invention, various fillers, stabilizers, coloring agents, abrasives, and the like can be added as needed.

(Examples) Hereinafter, the present invention will be described in detail based on examples.

Example 1 80 parts by weight of a styrene-based thermoplastic elastomer (Clayton G1650, manufactured by Shell Chemical Co., Ltd., hardness 75,
Tensile strength 352 kg / cm ² ) Heavy calcium carbonate 20 parts by weight Kneaton G1650 is kneaded with two rolls heated to 120 ° C. After sufficient kneading, the mixture is kneaded with two rolls while adding heavy calcium carbonate little by little. When you have finished adding heavy calcium carbonate, place it in a mold and
After heating and molding at 10 ° C. for 10 minutes, the product was cooled and taken out of the mold to obtain an eraser.

Example 2 100 parts by weight of a polyurethane-based thermoplastic elastomer (Elastolan E190 MNAT, Elastolan Japan Co., Ltd.)
, Hardness 90, tensile strength 400 kg / cm ² ) Knead the above Elastran E190 MNAT with two rolls heated to 180 ° C. After sufficient kneading, the above-mentioned Elastran E190 MNAT was packed in a mold, heated and molded at 180 ° C. for 10 minutes, cooled, and taken out of the mold to obtain an eraser.

Comparative Example 1 80 parts by weight of styrene-based thermoplastic elastomer (Califlex TR-1102 / KX-65, Shell Chemical Co., Ltd.)
, Hardness 62, tensile strength 324 kg / cm ² ) 20 parts by weight of heavy calcium carbonate Kariflex TR-1102 / KX-65 is kneaded with two rolls heated to 120 ° C. After sufficient kneading, the mixture is kneaded with two rolls while adding heavy calcium carbonate little by little. After the addition of the heavy calcium carbonate, the product was packed in a mold, heated and molded at 120 ° C. for 10 minutes, then cooled and taken out of the mold to obtain an eraser.

Comparative Example 2 80 parts by weight of thermoplastic elastomer (Elastor ES-1003, manufactured by Nippon Zeon Co., Ltd., hardness 8
6. Tensile strength 210 kg / cm ² ) Heavy calcium carbonate 20 parts by weight Knead the above elastor ES-1003 with two rolls heated to 120 ° C. After sufficient kneading, the mixture is kneaded with two rolls while adding heavy calcium carbonate little by little. After the addition of the heavy calcium carbonate, the product was packed in a mold, heated and molded at 120 ° C. for 10 minutes, then cooled and taken out of the mold to obtain an eraser.

Comparative Example 3 Polyester elastomer 80 parts by weight (Perprene S-2000, manufactured by Toyobo Co., Ltd., hardness 97, tensile strength 390 kg / cm ² ) Heavy calcium carbonate 20 parts by weight The above perprene S-2000 was heated to 200 ° C. Knead with two rolls. After sufficient kneading, the mixture is kneaded with two rolls while adding heavy calcium carbonate little by little.
After the addition of the heavy calcium carbonate, the material was packed in a mold, heated and molded at 200 ° C. for 10 minutes, cooled, and taken out of the mold to obtain an eraser.

Comparative Example 4 Polyurethane elastomer 80 parts by weight (Paraprene P25M, manufactured by Nippon Elastoln Co., Ltd., hardness 9
1. Tensile strength: 600 kg / cm ² ) 20 parts by weight of heavy calcium carbonate Knead the above paraprene P25M with two rolls heated to 230 ° C. After sufficient kneading, the mixture is kneaded with two rolls while adding heavy calcium carbonate little by little. After the addition of the heavy calcium carbonate, the product was packed in a mold, heated and molded at 230 ° C. for 10 minutes, cooled, and taken out of the mold to obtain an eraser.

(Effects) The erasers obtained in Examples 1 and 2 and Comparative Examples 1 to 4 were subjected to QE.11 (Electric eraser, Skylight Industry Co., Ltd.)
Xerox 5730 (Fuji Xerox Co., Ltd.)
Of Xerox paper L paper (manufactured by Fuji Xerox Co., Ltd.) was used to erase the electrostatic copy image. In Examples 1 and 2, the image could be easily erased without substantially damaging the paper surface. However, in Comparative Examples 1 and 2, the images could not be sufficiently erased, and in Comparative Examples 3 and 4, although the images could be erased, the paper surface was damaged.

As described above, the eraser for correcting an electrostatic copy image according to the present invention has an excellent effect that an image can be erased easily and surely.

Claims (1)

(57) [Claims] (1) Hardness (Hs, JIS K6301) is 70 or more and 95 or less,
An eraser for correcting electrostatic copy images, characterized by containing at least a thermoplastic elastomer resin having a tensile strength (JIS K6301) of not less than 250 kg / cm ^{2 and not} more than 500 kg / cm ² .