JPH01110999A - Plastic eraser - Google Patents

Abstract

PURPOSE: To greatly improve the utility of eraser by adding a specified charge preventing agent of 0.1 to 10 wt.% at blending when manufacturing plastic eraser. CONSTITUTION: Blended in eraser having styrene/butadiene copolymer as its main component is polyvalent alcohol or fatty acid ester of these polycondensed material or sorbic fatty acid ester compound to 0.1 to 10 wt.% in the process of manufacture before the blend. Addition of this charge preventing agent increased erasing ability against printing ink and others. Also, erased refuse stuck to paper face can easily be removed simply by holding the paper face vertical or lightly breathing.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention has a styrene-butadiene copolymer as its main component, which is combined with ethylene-vinyl acetate copolymer, acid polypropylene, polyethylene, ethylene-propylene copolymer or A blended polymer made by adding at least one kind of ionomer resin, etc., liquid paraffin, polybutene, etc. as a plasticizer, and an inorganic compound such as silica powder, magnesium oxide, calcium carbonate, talc, etc., or a sulfur compound such as factice as a filler. This invention relates to a styrene-butadiene copolymer-based plastic eraser made by adding .

豐 (Prior Art) The conventional method for manufacturing ji-eshi is simply to knead the above-mentioned compound and then heat-form it into a predetermined shape.

(Problem to be solved by the invention) Although such conventional letter erasers can be made with high hardness, they have superior erasability compared to vinyl chloride letter erasers, but they produce a large amount of letter eraser residue. There is a tendency to appear. These erased letters are strongly charged due to friction with the paper surface or friction between the erased letters and the erased letters, and cannot be removed by applying light vibrations to the paper surface from the outside. In cases such as this, when it is necessary to wipe away the characters, the erased residue often scatters to areas that do not require erasing and end up erasing them. This phenomenon becomes a big problem, especially when erasing small areas. Furthermore, when erasing finer details, vinyl chloride erasers do not have the hardness and have a brittle structure, so if they are processed into a small diameter such as a pencil, they will easily break, making them impractical.

(Means for Solving the Problems) Adding antistatic agents to polymers to improve workability or maintain the dustproof effect of finished products has already been practiced in a wide range of fields. However, with plastic erasers, this type of treatment is not carried out, so the eraser residue adheres to the paper surface1, and in order to remove it, one must use one's fingers or a brush as described above.

However, when blending in the production of kanji, polyhydric alcohols or fatty acid esters of their polycondensates, or sorbitan fatty acid esters, specifically decaglyceryl monostearate, decaglyceryl monostearate, and pentaerythritol stearate, are used. , sorbitan monostearate or sorbitan monooleate etc.
．． By adding 1 to 10 wt%, ideally 0.5 to 5 wt%, the above problems can be solved without impairing erasing performance.

(Function) Since the present invention is as described above, it not only improves workability such as mixing during the manufacturing process of the letter eraser and cleaning after kneading, but also improves workability when erasing letters using the completed letter eraser. Improving the degree of adhesion of the eraser to the paper surface, removing the eraser residue adhering to the paper surface,
Alternatively, the usability of the eraser can be greatly improved, such as by preventing debris from adhering to the eraser. That is, by simply blowing lightly on the surface of the erased paper, or by simply standing the paper vertically, the erased residue can be completely removed and the adhesion of the erased residue to the erased paper can be completely suppressed.

Furthermore, since the terminal group of the added compound is a highly hydrophobic alkyl group, ink for printed matter can be solubilized, and as a result, printed areas can be easily erased.

(Example) After briefly mixing the formulations shown in Table 1 with a Nigu,
The mixture was kneaded by passing through the air three times using a screw-type extrusion molding machine, and was molded into a predetermined shape in the fourth time.

Table 1. Formulation Example Table, 2 Molding Conditions Shape and Characteristics of 9-character Erase (Effects of the Invention) Workability was significantly improved by the addition of the antistatic agent. All of the completed letter erasers have good adhesion to the paper surface, have an excellent range of use, and have no change in the erasing performance of pencil letters; in fact, their ability to erase printing ink has improved. Also, the eraser residue that had adhered to the paper surface could be removed by simply standing the paper vertically or by lightly blowing on it. The hardness of the eraser is useful for erasing or correcting details, and these characteristics could not be obtained with conventional vinyl chloride erasers.

Claims (1)

[Claims] A charged product made by adding and kneading 0.1 to 10 wt % of a polyhydric alcohol, a fatty acid ester of a polycondensate thereof, or a sorbitan fatty acid ester compound to a styrene-butadiene copolymer as a main component during the styrene-butadiene copolymer manufacturing process. Plastic eraser with prevention effect.