Abstract: Disclosed is a decolorizable electrophotographic toner, including: a binder resin; and a colorant which contains at least a color developable compound and a color developing agent and is covered with an outer shell so as to have a capsule structure, wherein the number ratio of particles having an equivalent circle diameter of 0.6 ?m or more and 2.5 ?m or less of the toner when measured using a flow particle image analyzer after the toner is dispersed in an aqueous medium at a ratio of 0.08% by weight and the resulting dispersion is subjected to a stirring treatment in which stirring is performed at 5000 rpm for 30 minutes using a homogenizer (T-25 digital ULTRA-TURRAX (manufactured by IKA Japan K.K., provided with a shaft generator S25N-10G)) is 30% by number or less.

Abstract: The invention aims at providing a solid writing material that does not adversely affect the color changing property of script and can obtain sufficient strength. This aim is achieved by the solid writing material that includes: a reversible thermochromic microcapsuled pigment encapsulating a temperature-sensitive color-changeable color-memorizing composition; an excipient; and a resin; the temperature-sensitive color-changeable color-memorizing composition including at least (a) an electron-donating coloring organic compound, (b) an electron accepting compound and (c) a reaction medium effecting reversibly an electron transfer reaction between the (a) and (b) components in a specific temperature range; wherein the excipient or the resin includes a styrene-structure-containing polymer.

Abstract: A thermochromic writing instrument contains a thermochromic ink, wherein a writing body is accommodated in a barrel movably in a longitudinal direction, an operation portion is provided on the outer surface of the barrel, a pen tip of the writing body is constituted so as to be projectable/retractable from/into a front-end hole of the barrel by operating the operation portion, the thermochromic ink is contained in the inside of the writing body, the pen tip capable of ejecting the thermochromic ink is provided at the front end of the writing tool, and a friction portion capable of thermally changing the color of the handwriting of the thermochromic ink by the frictional heat generated when the handwriting is rubbed with the friction portion is provided on the outer surface of the barrel.

Abstract: A thermochromic writing instrument contains a thermochromic ink, wherein a writing body is accommodated in a barrel movably in a longitudinal direction, an operation portion is provided on the outer surface of the barrel, a pen tip of the writing body is constituted so as to be projectable/retractable from/into a front-end hole of the barrel by operating the operation portion, the thermochromic ink is contained in the inside of the writing body, the pen tip capable of ejecting the thermochromic ink is provided at the front end of the writing tool, and a friction portion capable of thermally changing the color of the handwriting of the thermochromic ink by the frictional heat generated when the handwriting is rubbed with the friction portion is provided on the outer surface of the barrel.

Abstract: When the rear axial cylinder (3) is rotated, the cam cylinder (17) is also rotated, thereby the cam protrusion (18a) moves forward by means of the functions of the cam groove (17a) and the slit (18b), so that the slider (18) moves forward to cause the writing body (14) to move forward against a biasing force by the biasing member (15). The slider (18) has the hollow body (18m), the coil spring (18c) and the flange body (18f). The O-ring (19) is provided on the outer circumference of the flange body (18f).

Abstract: A thermochromic writing instrument 1 including a writing body 9, storing a thermochromic ink therein, stored in a barrel 2; an operation body provided in the barrel 2 to be operated to longitudinally move the writing body 9; a nib 91 of the writing body 9 configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument 1 further includes a friction unit 10, for rubbing handwriting in the thermochromic ink and capable of thermally changing the color of the handwriting by frictional heat generated at that time, and at least one clip body 7 as the operation body, the friction unit 10 is provided at a rear end of the barrel 2, and the clip body 7 is provided in an area other than the rear end of the barrel 2.

Abstract: Provided are: an oil-based ink composition for a ball-point pen having a favorable feeling of writing, the favorable deepness of a written trace, favorable light resistance, favorable ink stability over time, and favorable pigment dispersibility; and an oil-based ball-point pen refill using the oil-based ink composition. An oil-based ink composition for a ball-point pen comprising at least a dye, a pigment, and an organic solvent, wherein the dye is at least one salt-forming dye selected from the group consisting of salt-forming dyes of alkylbenzene sulfonic acids and xanthene-based basic dyes, salt-forming dyes of alkylbenzene sulfonic acids and triarylmethane-based basic dyes, and salt-forming dyes of alkylbenzene sulfonic acids and azomethine-based basic dyes.

Abstract: [Object] To provide a reversibly thermochromic composition free from accidental discoloration by heat conducting from the opposite side writing surface or by self-heating due to quick writing; and also to provide a solid writing material and a writing ink composition comprising that composition. [Means to solve the problem] A reversibly thermochromic composition comprising a combination of: (a) a reversibly thermochromic component capable of being discolored or decolored by heat and (b) a component for controlling heat conducting to the reversibly thermochromic component; and also a solid writing material and a writing ink composition comprising that composition.

Abstract: This invention provides a needle for a living body and a process for sampling a tissue with the needle. The needle and the process are used for harvesting a tissue sample from a living body with minimal damage. The needle is made of ceramics, and is provided with a sampling hole for aspirating a sample and with a cooling hole for supplying cooling gas. The holes penetrate through in the longitudinal direction, and have openings on a pricking-end surface of the needle. For the purpose of cutting off the tissue sample, the pricking-end surface is provided with a cutting part positioned between the openings. When the needle is pricked into a body, a tissue is aspirated through the sampling hole while cooling gas is being supplied through the cooling hole. Thus, the tissue is partly frozen or semi-frozen and cut off with the cutting part to harvest by aspiration.

Abstract: A ballpoint pen tip includes a ball and a ball holder for rotatably holding the ball. The ball includes a ball body and a first carbonaceous film formed so as to cover a surface of the ball body. The first carbonaceous film has carbon atoms and oxygen atoms bonded to some of the carbon atoms. The ratio of carbon atoms bonded to oxygen atoms to the total carbon atoms at a surface of the first carbonaceous film is equal to or greater than 0.1.