JPH0732151Y2 - Plastic eraser - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to a plastic eraser among erasers.

(Prior Art) Various erasers are known in various aspects such as shape, application, and material. For example, in terms of shape, a rectangular parallelepiped is generally used, but there are also various shapes of objects. In terms of application, a pencil lead is generally used for erasing the handwriting, but there are also those for erasing the printed surface of the printed matter and those for erasing the handwriting of the oil-based marker drawn on the film. In terms of material, it is similar to materials such as polyvinyl chloride-based materials, natural rubber-based materials, thermoplastic elastomer-based materials, or handwriting abrasive powders in what is commonly called "sand eraser". Many are known about various fillers and other materials.

Of these, materials other than natural rubber-based materials such as polyvinyl chloride-based materials and thermoplastic elastomer-based materials are generally called plastic erasers.

(Problems to be Solved by the Invention) Although plastic erasers are generally superior in erasability to erasers of natural rubber-based materials, they have the drawback of being slippery. That is, the plastic eraser is usually formed with a skin such as a paper container or a film roll.
However, the outer skin is often torn and the body is used as it is. In addition, there are some products that are sold as they are without the formation of a skin. As described above, slippage is a problem that occurs when the plastic eraser is used as it is.
Especially, when you are sweating, it is a problem that you are most concerned about.

(Means for Solving Problems) A plastic eraser having a specific matte surface is used. That is, the present invention is a plastic eraser having a satin-finished surface, wherein the unevenness of the satin-finished surface is 2 to 6 μm.
The outline is the plastic eraser, which is characterized by the average roughness of the center line.

The center line average roughness is obtained by measurement by the stylus method. That is, touch the needle of the measuring machine to the plastic eraser surface,
When this needle and the plastic eraser are moved relative to each other, the needle moves up and down according to the unevenness of the plastic eraser surface, and this is measured. By the way, although the stylus method itself is also shown in JIS B 0601, etc., since the value will vary greatly depending on the measuring instrument and measuring conditions, the measuring instrument and measuring conditions used by the present inventor are as follows. Indicates.

Measuring instrument ・ Made by Tokyo Seimitsu Co., Ltd. ・ Surfcom 550A type surface roughness profile measuring machine Centerline average roughness measuring condition ・ Measuring element type: E-DT-S03A Stylus: 2 μm R 90 ° conical diamond ・ Drive speed (scanning) Speed): 0.3mm / sec ・ Measurement length: 2.5mm ・ VERTICAL MAG. (Vertical magnification): × 1000 ・ Cutoff value: 0.8mm (measured at 3 different points and averaged) The reason why the line average roughness is preferably 2 to 6 μm is as follows.

When the center line average roughness is 2 μm or less, the slip prevention due to the unevenness on the matte surface is insufficient. Further, if it is 6 μm or more, there is no problem in terms of preventing slippage, but stains are accumulated on the unevenness, and the problem that this stain stains the writing surface when erasing the handwriting cannot be ignored. Besides, the surface is often printed, but if it is 6 μm or more, it becomes difficult to print neatly. Among these, 3 μm to 4 μm
The degree is the most preferable.

By the way, depending on the surface roughness profile measuring device, not only the center line average roughness but also the “surface waviness” defined in JIS B 0610 can be measured. The measuring instrument used by the present inventor is one of them, and the measurement conditions for surface waviness are also described below.

Measurement conditions for surface waviness ・ Measurement type: maximum waviness of filtered wave ・ Stylus type: E-DT-S03A Stylus: 2 μm R 90 ° conical diamond ・ Drive speed (scanning speed): 0.3 mm / sec ・ Measuring length: 8 mm・ VERTICAL MAG. (Vertical magnification): × 1000 ・ Cutoff value: 0.8 mm (measured at three different points and averaged) By the way, this surface waviness (maximum waviness of filtered wave) is 10 to 30 μm. Was good.

(Example) An example is shown in the attached FIG. The plastic eraser 1 has a flat plate shape, for example, a cash card size and 2 to 6 m.
It has a thickness of about m. In the figure, the area 2 surrounded by the alternate long and short dash line is the matte surface. The entire plastic eraser may have a satin-finished surface, but it indicates that the necessary portion has a satin-finished surface. In other words, in the flat plastic eraser, the flat plate surface serves exclusively as the grip portion.

In addition, a plastic eraser such as the plastic eraser 1 may be manufactured by injection molding in many cases. For example, a corresponding portion of a mold that is usually mirror-finished is etched by an appropriate acid. If it is applied, a product having a satin surface can be easily obtained.

The material of the plastic eraser 1 is appropriate. However, when the thickness is thin, it is preferable to use a thermoplastic elastomer-based substrate having high strength. The following is an example.

Styrene-butadiene block copolymer 100 Ethylene ethyl acrylate 30-100 Calcium carbonate 20-200 Naphthene oil 0-50 Fatty acid metal salt 0-5 Coloring agent 0-10 Anti-aging agent 0-5 (Numbers are parts by weight) ) Width as the plastic eraser 1 mentioned in the item of the embodiment
A material having a length of 8 cm, a width of 5 cm, and a thickness of 3 mm was obtained by using the material of the styrene-butadiene block copolymer base material also described in the section of Examples. Here, the obtained products are 6 types (Examples 1 to 6) having different satin-like surface states. Table 1 shows the results of measuring the surface condition of this with a commercially available plastic eraser (of a polyvinyl chloride base material) (Examples 7 and 8).

Further, when the samples of Examples 1 to 6 were examined for slipperiness and ease of silk printing, they were as shown in Table-2.

Thus, according to the plastic eraser of the present invention, the problem of slipperiness is improved without causing another problem of defective printing.

[Brief description of drawings]

 FIG. 1 is a perspective view showing an embodiment of the present invention. 1 ... plastic eraser 2 ... satin surface area

Claims (1)

[Scope of utility model registration request] 1. A plastic eraser having a satin surface, wherein the irregularities on the satin surface have a center line average roughness of 2 to 6 μm.