Abstract: [Problems] To provide a reversibly thermochromic composition having excellent contrast between a colored state and a decolored state, and excellent light resistance, and a reversibly thermochromic microcapsule pigment encapsulating the reversibly thermochromic composition. [Solution] Disclosed is a reversibly thermochromic composition including: (a) an electron-donating color-developing organic compound; (b) a combination of a compound having a specific structure as an electron-accepting compound; and (c) a reaction medium which reversibly induces an electron transfer reaction between the component (a) and the component (b) in a specific temperature range, and a reversibly thermochromic microcapsule pigment encapsulating the reversibly thermochromic composition.

Abstract: [Problems] To provided are a reversibly thermochromic composition that shows black during color development by using a fluoran derivative having a specific structure as an electron-donating color-developing organic compound, turns colorless during decoloration, and is excellent in light resistance and a microcapsule pigment encapsulating the reversibly thermochromic composition. [Solution] Disclosed is a reversibly thermochromic composition including: (a) a fluoran derivative having a specific structure as an electron-donating color-developing organic compound; (b) a compound having a specific structure as an electron-accepting compound; and (c) a reaction medium which reversibly induces an electron transfer reaction between the component (a) and the component (b) in a specific temperature range, and a reversibly thermochromic microcapsule pigment encapsulating the reversibly thermochromic composition.

Abstract: An image forming apparatus includes: a first supplying device configured to supply a first ink onto a recording medium to form a non-color print layer on the recording medium, the first ink comprising non-color particles; and a second supplying device configured to supply a second ink onto the recording medium having the non-color print layer formed thereon, to form a color print layer on the recording medium, the second ink including color pigment particles that are decolored when heated.

Abstract: [Problems] Provided are a highly marketable reversibly thermochromic composition that provides a black color during color development by using a fluoran derivative having a specific structure as an electron-donating color-developing organic compound, turns colorless during decoloration, and is excellent in contrast between a colored state and a decolored state and a microcapsule pigment encapsulating the same. [Solution] Disclosed are a reversibly thermochromic composition including: (a) a fluoran derivative having a specific structure as an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) a reaction medium which reversibly induces an electron transfer reaction between the component (a) and the component (b) in a specific temperature range, and a reversibly thermochromic microcapsule pigment encapsulating the same.

Abstract: To provide a reversibly thermochromic aqueous ink composition excellent in dispersion stability of a reversibly thermochromic microcapsule pigment and a writing instrument using the same. Disclosed is a reversibly thermochromic aqueous ink composition comprising a reversibly thermochromic microcapsule pigment encapsulating a reversibly thermochromic composition comprising (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium to determine an occurrence temperature of a coloring reaction of the component (a) and the component (b), and a vehicle comprising water and a specific gravity adjuster selected from the group consisting of an oxyacid belonging to Group 6 having an atomic weight of 90 to 185 or salt thereof.

Abstract: Disclosed is a photochromic composition comprising a naphthopyran-based photochromic compound having a specific structure and an oligomer.

Abstract: A thermochromic writing instrument including a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument 1 further includes a friction unit, 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 as the operation body, the friction unit 10 is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

Abstract: To provide a reversibly thermochromic composite fiber having a reversible color change due to a temperature change, having such excellent flame retardancy that flame is hard to spread even if ignition occurs once, and having high safety. [Solution] Disclosed is a sheath-core type reversibly thermochromic composite fiber including a core comprising a resin, a reversibly thermochromic pigment, and a flame retardant, and a sheath comprising a resin and a flame retardant.

Abstract: [Problems] The present invention provides a highly marketable reversibly color changeable composition which provides a vivid yellow to orange color during color development, turns colorless during decoloration, and improves light resistance and a reversibly thermochromic microcapsule pigment encapsulating the same. [Solution] Disclosed are a reversibly thermochromic composition including: (a) a specific pyridine derivative as an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) a reaction medium which reversibly induces an electron transfer reaction between the component (a) and the component (b) in a specific temperature range, and a reversibly thermochromic microcapsule pigment encapsulating the same.

Abstract: [Problems] Provided is a discoloring body which is discolored by application of water and has high glossiness and is excellent in applicability to various fields such as a toy field, a decoration field, and a design field. [Solution] A discoloring body including a supporting body, a porous layer in which a low refractive index pigment is fixed in a dispersed state by way of a binder resin, and a glossy resin layer, in which an occupancy area ratio of the glossy resin layer is 1% to 95% with respect to a 1 cm square at any position in the porous layer.

Abstract: An ink composition for a reversibly thermochromic stamp including a reversibly thermochromic microencapsulated pigment encapsulating a reversibly thermochromic composition including: Component (A): an electron-donating color-developing organic compound, Component (B): an electron-accepting compound, and Component (C): a reaction medium causing reversibly an electron transfer reaction between the Component (A) and the Component (B) in a specific temperature range, water and a thickener.

Abstract: To provide a reversibly thermochromic aqueous ink composition excellent in dispersion stability of a reversibly thermochromic microcapsule pigment and a writing instrument using the same. Disclosed is a reversibly thermochromic aqueous ink composition comprising a reversibly thermochromic microcapsule pigment encapsulating a reversibly thermochromic composition comprising (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium to determine an occurrence temperature of a coloring reaction of the component (a) and the component (b), and a vehicle comprising water and a specific gravity adjuster selected from the group consisting of an oxyacid belonging to Group 6 having an atomic weight of 90 to 185 or salt thereof.

Abstract: The present invention provides a thermochromic color-memory composition including (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) an ester compound represented by the following formula (1) or (2), as a reaction medium which controls color reaction of the component (a) and the component (b); and a thermochromic color-memory microcapsule pigment encapsulating the thermochromic color-memory composition.

Abstract: [Problems] The present invention provides a highly marketable reversibly color changeable composition which provides a vivid yellow to orange color during color development, turns colorless during decoloration, and improves light resistance and a reversibly thermochromic microcapsule pigment encapsulating the same. [Solution] Disclosed are a reversibly thermochromic composition including: (a) a specific pyridine derivative as an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) a reaction medium which reversibly induces an electron transfer reaction between the component (a) and the component (b) in a specific temperature range, and a reversibly thermochromic microcapsule pigment encapsulating the same.

Abstract: A thermochromic writing instrument including a writing body, storing a thermochromic ink therein, stored in a barrel; an operation body provided in the barrel to be operated to longitudinally move the writing body; a nib of the writing body configured to be capable of appearing from a front end of the writing instrument, wherein the writing instrument 1 further includes a friction unit, 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 as the operation body, the friction unit 10 is provided at a rear end of the barrel, and the clip body is provided in an area other than the rear end of the barrel.

Abstract: [Problems] An object of the present invention is to provide: a thermochromic color-memory composition which effectively expresses a property of being able to interchangeably memorize and retain colors and which is thus applicable to various fields; and a thermochromic color-memory microcapsule pigment encapsulating the same.

Abstract: [Problems] An object of the present invention is to provide: a thermochromic color-memory composition which effectively expresses a property of being able to interchangeably memorize and retain colors and which is thus applicable to various fields; and a thermochromic color-memory microcapsule pigment encapsulating the same.

Abstract: The present invention relates to a photochromic toy containing a light irradiator equipped with a light source and a toy main body containing a photochromic compound, in which the light source has a peak wavelength in the range of from 400 nm to 495 nm and the photochromic compound satisfies the following expression (1) between the integrated value of absorbance (x) in the range of from a wavelength showing a maximum absorbance in less than 400 nm to a wavelength of 400 nm and the integrated value of absorbance (y) in the wavelength range of from 400 nm to 700 nm. y/x?0.

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: Provided are thermochromic color-memorizing composition and thermochromic color-memorizing microcapsule pigment encapsulating the same, the thermochromic color-memorizing composition including: (a) an electron-donating color-developing organic compound; (b) an electron-accepting compound; and (c) an ester compound represented by the following formula (1) as a reaction medium which controls color reaction between the components (a) and (b):