JPS6357299A - Eraser for white board - Google Patents

Abstract

(57) [Abstract] 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 relates to an eraser suitable for use in whiteboards that can display characters and the like in an erasable manner using water-based ink.

"Prior Art and Problems" Conventional whiteboard erasers are made of ordinary whiteboard erasers, such as cotton or sponge wrapped in cor-ten cloth like the well-known blackboard eraser, or simply laminated non-woven fabrics. It was made from cloth.

By the way, the problem with the conventional eraser mentioned above is that the erasing ability deteriorates rapidly over time.Also, even if the eraser is new, if characters, etc. on the whiteboard are left for a long time, they may remain unerased. There is a problem in that it is easy to occur.

"Means for Solving the Problems" The present inventor has conducted extensive research to solve the above-mentioned conventional problems, and has come to the following knowledge.

The erasing ability of conventional erasers decreases rapidly because the ink powder scraped from the whiteboard surface enters between the fibers on the cloth surface and eventually covers the eraser surface. The main cause of ink powder adhesion to the eraser surface is static electricity generated between the whiteboard and the eraser. When we look at the generation of static electricity on the surface of a whiteboard made of vinyl chloride resin sheets, we find that, for example, at 20°C and 40% humidity, the static electricity is 3800 to 4500V, which is very high. is occurring. Therefore, the letters on a whiteboard that have been left for a long time are completely dry, so when you wipe them off, a high amount of static electricity is generated on the whiteboard, which attracts the ink powder and prevents it from being removed.
This causes unerased parts. A possible solution to this problem is to dampen the cloth and wipe it off, but if you use a damp cloth, the ink will be diluted and spread over the entire surface of the whiteboard, instead staining the surface of the whiteboard.

This invention was made based on the above knowledge, and by forming the eraser from a fiber aggregate mixed with conductive fibers, it is possible to prevent static electricity from being generated on the whiteboard and on the eraser during wiping. This prevents ink powder from remaining on the whiteboard and prevents the eraser from clogging with ink powder. As the fiber aggregate, woven fabrics, knitted fabrics, nonwoven fabrics, etc. can be considered.

In order for the eraser of the present invention to exhibit practical effects, the proportion of conductive fibers on the exposed surface of the eraser must be 0.5 to 20 wt%, preferably 1 to 10 wt%. be. Depending on this mixing ratio, the surface resistivity value of the eraser takes on a value of 104 to 10@Ω/ohm or around it, and when the surface of the whiteboard is rubbed, the frictional voltage on the whiteboard will be 200V or less, and there will be sufficient static electricity. removal ability can be obtained. This conductive fiber is, for example, made of synthetic resin or natural fiber impregnated with a copper compound such as cuprous sulfide or cupric sulfide, or plated with metal, and has a length of 7
~60++u+, and the aspect ratio is preferably 300 or more in order to ensure static electricity prevention or removal function and maintain dispersibility during fiber aggregate formation.

Examples of this invention will be shown below.

"Example 1" Acrylic fiber containing cuprous sulfide and having a diameter of 8 μm and a length of 51 m+; 3 wt%, diameter of 14 μm shoulder, length of 51 mm
Rayon fiber; 80 wt% and binder fiber (polyester heat-fusible fiber); 17 wt% were mixed to form a random web dry nonwoven fabric with a basis weight of 7O-3 = 9/m. A whiteboard eraser was obtained by sewing and molding it into the shape of a well-known blackboard eraser.

The surface specific resistance value of the obtained eraser under the conditions of 20 ° C. and 40% RH was 5 ° 5 × 10 5 Ω / mouth,
This eraser erases the whiteboard surface at 200C.
, 40%R1 (when the charged voltage on the surface of the whiteboard was measured when rubbed under the conditions of 140 V.

Also, when I used this eraser to wipe off the text I had written all over the whiteboard the previous day, I was able to erase it cleanly without leaving anything behind.

"Example 2" Acrylic spun yarn with electroless nickel plating 2/48
S: The eraser was composed of a tenagasa knitted fabric knitted at a ratio of 4OS/2.9 parts by weight of cotton yarn to 1 part by weight to give a basis weight of 1309/12.

The surface resistivity value of the obtained eraser under the conditions of 20°C and 140%RH was 8. OX 107Ω/mouth, and this eraser can erase the whiteboard surface by 200Ω.
The electrostatic voltage on the surface of the whiteboard when rubbed under the conditions of C, 40% R1 was measured and found to be 250V.

Also, when I used this eraser to wipe off the text I had written all over the whiteboard the previous day, I was able to erase it cleanly without leaving anything behind.

"Effects of the Invention" As explained above, the whiteboard eraser of the present invention can prevent static electricity from being generated on the whiteboard and the eraser during wiping, and no ink powder will remain on the whiteboard. In addition to doing so,
The eraser can be prevented from being clogged with ink powder, and ink on the whiteboard after a long period of time can be easily and reliably erased.

Claims (1)

[Claims] This is a whiteboard eraser for scraping characters written with water-based ink on a whiteboard whose surface is covered with plastic. An eraser for whiteboards, characterized in that the proportion of sexual fibers is 0.5 to 20 wt%.