Abstract: A color-changeable toy having a toy body to which a quasi-reversible thermochromic material is applied in a pattern. This material stably holds either of two colored states in a range of ordinary room temperatures. However, the material reversibly changes to one of the states above this range and to the other below this range. Thereby, by using commonly available heat and chilling sources such as ice, hot water or breath, one of the colors can be selected. A breath blow pipe can be used in conjunction with the toy and have an external appearance associated with that of the toy, e.g., gun and soldier.

Abstract: An toy set having at least one section which bears a color memory dye of an electron-supplying organic coloring compound, an electron accepting compound and an ester. The color memory dye assumes a first color below t1 (.degree.C.) and a second color above t2 (.degree.C.), wherein t2>t1, 0.ltoreq.t1, t2.ltoreq.50.degree. C. and 5.ltoreq.t2-t1.ltoreq.35. Both the first and second colors can be displayed between t1 and t2. For the purpose of determining the proper temperature range for a color characteristic, temperature-sensitive visual indicators are provided.

Abstract: An artificial plant having at least one section which bears a color memory dye of an electron-supplying organic coloring compound, an electron accepting compound an an ester. The color memory dye assumes a first color below t1 (.degree. C.) and a second color above t2 (.degree. C.), wherein t2>t1, 0.ltoreq.t1, t2.ltoreq.50.degree. C. and 5.ltoreq.t2-t1.ltoreq.35. Both the first and second colors can be displayed between t1 and t2.

Abstract: A color memory toy set has a color memory toy with surface, at least one portion of the surface being provided with a color memory temperature-sensitive color changing layer colored with a coloring material including a color memory temperature-sensitive dye exhibiting hysteresis characteristics in response to temperature change between a colored state and a colorless state or between a color (I) state and a color (II) state. The toy set also includes a writing pen for either causing an image to appear or disappear on the color memory temperature-sensitive layer by drawing the image on the layer to change the color state of the drawn portion into a first state, or for causing an image to appear or disappear on the color memory temperature-sensitive layer by drawing the image on the layer to change the color state of the drawn portion to a second state.

Abstract: Disclosed is a thermochromic artificial nail comprising an artificial nail having provided thereon a thermochromic layer, which comprises a thermochromic material changeable in visible external color in response to a change in temperature, wherein said thermochromic layer has a thickness of at least 1 .mu.m.

Abstract: A new reversible heat sensitive recording composition for erasable recording is disclosed which is used as a recording or marking material that is capable of erasure at a specific temperature so that coloring or decoloring can be controlled to occur at desired temperature ranges. This range or the hysteresis value of the composition is determined by the .DELTA.T value of the contained ester compound. In addition, the compostion can provide a wide variety of hues and can readily be prepared. The marking or recording drawn in this composition can be maintained at room temperature or less.

Abstract: A new reversible temperature indicating composition for use in temperature indicating instruments is diclosed which is capable of accurate temperature indication in a variety of colors and characterized by a minimum range of hysteresis so that the marking drawn in this composition can decolor at or close the temperature at which its coloring takes place. In addition, the composition can provide a wide variety of hues and can be readily prepared. These and other advantages are provided by the inclusion as a main ingredient of an ester compound having .DELTA.T value, defined .DELTA.T=melting point--clouding point, in the range under 3.degree. C., the value that determines a desirably small range of hysteresis.

Abstract: A new reversible heat sensitive recording composition for erasable recording is disclosed which is used as a recording or marking material that is capable of erasure at a specific temperature so that coloring or decoloring can be controlled to occur at desired temperature ranges. This range or the hysteresis value of the composition is determined by the .DELTA.T value of the contained ester compound. In addition, the composition can provide a wide variety of hues and can readily be prepared. The marking or recording drawn in this composition can be maintained at room temperature or less.

Abstract: A textile material in the form of fiber, raw stock, yarn or fabric, which comprises fibers each of which is coated with a thermochromic layer containing a thermochromic pigment having a particle size satisfying the formula: ##EQU1## wherein r represents a particle size of a pigment; D represents fineness (denier) of a fiber; and d represents a density (g/cm.sup.3) of a fiber. The textile material can undergo reversible color change in a wide variety of colors and can be applied to any kind of textile products.

Abstract: A method for producing a reversible thermochromic display composed of multiple, overlapping color images. In accordance with the invention, a plurality of overlapping colored image layers are formed on a support, at least one of which layers provides a reversible thermochromic image. Each of the images on the various layers has a different visual density, and at least one reversible thermochromic image changes color at a temperature below or above a predetermined temperature and provides a color which is more intense and more easily discernible than the colors of the other ones of the images.

Abstract: A thermochromic material is described which comprises (a) an electron-donating, chromatic organic compound, (b) a compound capable of reversibly accepting an electron or electrons from the electron-donating, chromatic organic compound, (c) a compound controlling the temperature and sensitivity of coloration/decoloration of the thermochromic material and (d) a N-radical, P-radical, O-radical or S-radical cationic compound having an aromatic ring or rings which improves by light-fastness.

Abstract: A reversible thermochromic material is disclosed in the application. The material is comprised of (A) an electron-donating chromatic organic compound and (B) an acidic phosphoric acid ester compound or metal salt thereof, wherein Components (A) and (B) are contained in a weight ratio of 1:1/10 to 50 by weight. The material may also contain a third Component (C) for controlling the temperature of coloration/decoloration of the thermochromatic material. The thermochromatic material undergoes reversible metachromatism at a temperature within the range of -50.degree. C. to 120.degree. C. Furthermore, the reversible thermochromic material may be contained within microcapsules.

Abstract: An excellent thermochromic material exhibiting a sharp and reversible metachromatism at temperatures within a range of from -40.degree. to 80.degree. C can be formed from (A) an electron-donating, chromatic organic compound; (B) a compound containing a phenolic hydroxyl group; (C) a compound selected from the group consisting of higher aliphatic monovalent alcohols; and (D) a compound selected from the group consisting of higher aliphatic monovalent acid alcohol esters. The excellent thermochromic characteristics of such a thermochromic material can be further improved when it is occluded in fine microcapsules having a size not exceeding 50 .mu.. Thermochromic polymers, thermochromic printing inks, thermochromic writing instruments, thermochromic paints and thermochromic sheets having excellent thermochromatic characteristics and wide utility can be prepared from such a thermochromic material or microencapsulated thermochromic material.