JPH0236281A - Color pencil lead and crayon erasable with eraser - Google Patents

Abstract

PURPOSE:To obtain the subject lead and crayon, having soft writing conditions, capable of wet-on-wet coating and rich in coloring properties with a sufficient breaking strength without fouling paper surfaces after writing by using a thermoplastic resin, lubricant, cellular inorganic substance-containing extender material and pigment as principal materials. CONSTITUTION:The objective lead and crayon containing (A) a thermoplastic copolymer consisting of, e.g., PE or PP and ethylene/vinyl acetate copolymer, (B) a lubricant, such as higher fatty acid, metallic soap or paraffin wax, (C) an extender material, such as talc, titanium oxide or calcium carbonate, containing cellular inorganic substances and (D) a pigment as principal materials. Furthermore, cellular silica, diatomaceous earth powder, etc., are cited as examples of the cellular inorganic substances.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention uses a thermoplastic resin, a lubricant, an extender, and a pigment as main materials, and contains at least a porous inorganic material as the extender. To provide a colored pencil lead and a crayon that have a soft writing feel, rich colorability, can be coated over and over again, do not stain the paper surface after writing, have sufficient breakage strength, and can be easily erased with an eraser.

(Prior art) Colored pencil leads, crayons, etc. that can be erased with this type of eraser have conventionally been made of pigments, coloring materials such as dyes, body materials, lubricating white powders (for example, metal soap), and caking materials. (Japanese Patent Publication No. 47-48564) Furthermore, polyethylene, polymers of olefin compounds other than ethylene, petroleum wax, and synthetic rubber contain at least one of natural resins, vegetable waxes, and fatty acid salts that are solid at room temperature. (Japanese Patent Publication No. 58-23423) has been proposed, but it has not yet been possible to simultaneously satisfy all physical properties such as softness of writing, coloring strength, breakage strength, and erasability with an eraser.

(Problems to be Solved by the Invention) Conventional erasers and erasable colored pencil leads and crayons obtained in this way are soft when writing, although their breakage strength can be improved if emphasis is placed on erasability with the eraser. On the other hand, if the main focus is on the softness of writing and the colorability, the breakage strength will decrease and the erasability with an eraser will be poor.

In other words, with conventional products, when one physical property is improved, the quality of another is impaired, but the present invention effectively exhibits the four physical properties mentioned above at the same time, and can be coated over and over, and the paper surface after writing can be improved. It means not getting dirty.

(Means for solving the problems) In order to solve these problems, thermoplastic resins, especially polyethylene, polymers of polyolefin compounds other than ethylene, higher fatty acids, metal soaps, lubricants such as paraffin wax, talc, titanium oxide, An extender such as calcium carbonate and a pigment were used as main materials, and at least a porous inorganic substance was substituted and added as the extender.

These porous inorganic materials include, for example, porous silica diatomaceous earth powder, and because the molecules do not aggregate in their structure and have many micropores and gaps, they have a very large volume ratio and exhibit high absorbency, and are also used as fillers for erasers. Compared to using only a non-porous inorganic filler as an extender, when the lubricant and pigment are kept at a certain level, it is better to use a porous inorganic filler in combination with a porous inorganic filler or a porous inorganic filler alone. The quality of erasable colored pencil leads and crayons has improved significantly. In other words, when a non-porous inorganic filler and a porous inorganic material are used together or a porous inorganic material is used alone as a bulking material, it is possible to reduce the content ratio of the bulking material and increase the amount of thermoplastic resin as a caking agent. Therefore, these molded products have sufficient breaking strength, and by adding porous inorganic materials, they exhibit unique abrasion characteristics even when the amount of caking agent is increased, are resistant to coloring, and have a good writing quality. It was soft to the touch and had excellent erasability with an eraser, and could also be overpainted without staining the paper surface after writing.

(Example) The present invention will be explained in more detail below based on Examples.

[Example 1] [Comparative example] Porous inorganic material Porous silica pigment 5 [Example 2] The above blended composition was heated and melted and mixed in a Henschel mixer, then subjected to roll treatment, and after cooling the film-like material from the roll. It was pelletized and injection molded to obtain a rod-shaped molded product with a diameter of 7.5 fi. Table 1 compares the physical properties of these molded products, such as soft writing, colorability, breakage strength, and erasability.
As shown.

Porous inorganic material Diatomaceous earth powder pigment note) Book 1 - Judgment by human sense when writing randomly *2 - Rod-shaped molded object on Ghent paper (tip angle 25°, tip diameter 1.000 t)
mφ) was applied vertically, a load of 500 g was applied, and lines were drawn in the longitudinal direction of the test paper at a speed of 300 to 320 cIl/min, and the amount of wear per unit writing distance [fl/Il] was expressed. (Measured at room temperature 24℃, humidity 62%) Book 3 - Measured at 100 cranes with a span of 20℃ at room temperature *4 → Using drawing paper No. A-1, fill in the surface of 20mm vertically and 50m horizontally with a rod-shaped molded material, The eraser was arbitrarily rubbed back and forth 5 times, and the erased area was visually observed and judged.

(Effects of the Invention) According to the present invention, by using at least part or all of the porous inorganic material, it is possible to reduce the content ratio of the body material in the composition and increase the amount of the thermoplastic flank which is the caking material. As a result, contradictory physical properties such as softness, colorability, breakage strength, and erasability were all sufficiently maintained.

Claims (1)

[Claims] A colored pencil lead and a crayon that are erasable with an eraser, characterized by using a thermoplastic resin, a lubricant, an extender, and a pigment as main materials, and containing at least a porous inorganic material as the extender.