Sakura Color Products Corporation

Shinji Tsujio

Hidetoshi Fukuo

The invention provides a plastic eraser comprising a vinyl chloride resin as a base resin and a combination of 4,5-epoxy-1,2-cyclohexanedicarboxylic acid bis(2-ethylhexyl) and diethylene glycol dibenzoate as plasticizers, wherein the plastic eraser comprises the base resin in an amount of 25-60% by weight, and the combination of plasticizers in an amount of 30-60% by weight, and wherein the proportion of the diethylene glycol dibenzoate in the combination of plasticizers is 5-60% by weight, and wherein the plastic eraser has a hardness in the range of 55-75, and a gel hardness in the range of 3.0-6.0 kgf.

Plastic eraser, plastic eraser composite body, and method for producing thereof

The invention provides an aqueous ink composition which can be erased relatively easily even after writing with a great tool force. The invention relates to (1) an erasable aqueous ink composition containing at least one colorant, characterized in that the colorant has a mean particle size of not less than 2 &mgr;m and that particles having a size of not more than 1.8 &mgr;m account for not more than 1.6% by weight of said colorant; (2) an erasable aqueous ink composition containing at least one colorant, characterized in that the colorant has a mean particle size of not more than 7 &mgr;m and that particles having a size of not less than 7 &mgr;m account for not more than 0.5% by weight of said colorant and (3) an erasable aqueous ink composition containing at least one colorant, characterized in that the colorant has a mean particle size of 2 to 7 &mgr;m, that particles having a size of not more than 1.8 &mgr;m account for not more than 1.6% by weight of said colorant and that particles having a size of not less than 7 &mgr;m account for not more than 0.5% by weight of said colorant.

Erasable ink and water-base ballpoint pen using same

An object of this invention is to provide an ink composition with particularly excellent erasability and fixability, the erasability not declining with the lapse of time. This invention provides an erasable ink composition comprising a colorant, a film-forming resin and a release agent.

Erasable ink composition

A primary object of this invention is to provide a novel crayon which assures that the crayon has all of higher safety, superior writability and improved adhesion, and the invention provides a crayon containing a pigment component, a gelling agent, an organic solvent and a resin component, the organic solvent consisting of propylene glycol monomethyl ether and dipropylene glycol monomethyl ether.

Crayon

There is provided a novel fluorescent crayon having the quality characteristics of high coloring power, good drawing quality, and good adhesion all in one, while overcoming the drawbacks of the conventional crayon, that is to say a fluorescent crayon comprising a solution type fluorescent coloring agent, a gelling agent, an organic solvent and a resin component.

Fluorescent crayon

A method for manufacturing pencil leads which comprises thoroughly mixing 100 parts by weight of graphite, 30 to 60 parts by weight of a water-soluble nigrosine, an emulsion containing 10 to 30 parts by weight of wax, and water together, extruding the resultant base mixture from a die into rods of a desired diameter, drying the rods to remove the water contained therein, and then baking the rods at elevated temperatures. The base mixture may contain 10 to 30 parts by weight of a water-soluble organic nonelectrolyte of high molecular weight such as cellulose ethers and/or not more than 10 parts by weight of carbon black in relation to 100 parts by weight of graphite so as to further improve the quality of the leads obtained.

Growing community of inventors

Sakai, Japan

Shinji Tsujio