Color memory toy set

Abstract: A color memory toy set comprises a color memory toy (1) having a surface of a pattern, at least one portion of the surface being provided with a color memory temperature-­ sensitive color changing layer (11) 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; a hot-pen for causing an image (4) to appear or disappear on the color memory temperature-sensitive layer (11) by drawing the image (4) on the layer (11) to change the color state of the drawn portion (4) into a first state; and a cold-pen (3) for causing an image (4) to appear or disappear on the color memory temperature-sensitive layer (11) by drawing the image (4) on the layer (11) to change the color state of the drawn portion (4) to a second state.

Description: The present invention relates to a color memory toy set, more particularly to a color memory toy set comprising a color memory toy, a hot-pen and a cold-pen, wherein a user uses the pens to draw an arbitrary image on or mark a color memory temperature-sensitive color changing layer of the color memory toy so as to cause the drawn image or mark to appear or disappear. Conventionally, temperature-sensitive color changing materials including a reversible temperature-sensitive color changing dye have found extensive use in a wide variety of fields. They are of a type having a color-changing temperature at which the material exhibits a change in color. The material can take only specific one of two color states at normal temperatures. That is, the toy can stay in the other state only while it is supplied with either heating or chilling which is required to cause that state to appear, and returns to the one state appearing in a normal temperature range as soon as the heating or chilling is terminated. A quasi-reversible temperature-sensitive color changing material has been developed, which uses a quasi-reversible temperature-sensitive dye disclosed in U.S. Patent No. 4,720,301 assigned to Pilot Ink Co., Ltd.. This material exhibits hysteresis characteristics in response to temperature change, in which not only the surface color changes between a colorless state and a colored state or between a color (I) and a color (II) in response to a change in temperature, but also exhibits a duality that any one of the two color states can be selectively maintained at normal temperatures. A color memory toy using such a material has been considered. A further prior art of interest is GB-A-2 205 255 that teaches a thermochromic layer on the surface of a toy that can be changed by a wet color changing means such as a brush, sponge or cloth soaked with cold or hot water. According to the present invention as set out hereinafter, however, special pens are provided in a toy set, which pens can be filled with a hot or cold medium, said pens having a closed tip. This means that when the pens are filled with a liquid medium there is no transfer of said liquid to the color memory toy when the tip of said pens is used to draw on the toy to change its color. SUMMARY OF THE INVENTION An object of the present invention is to provide a color memory toy set comprising a heating or a chilling means which permits a user to change the color of part of a color memory toy or to return the color of that part to its previous color, i.e., which permits the user to make a arbitrary drawn image or mark, or to easily erase the image or mark, thereby effectively bringing out the characteristics of the color memory toy to enhance the toy property and variety of change. According to the present invention a color memory toy set comprises: a color memory toy having a surface of a pattern, at least one portion of said 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; one or more pens, each pen comprising a barrel having a closed tip serving as a writing tip and the arrangement being such that said barrel can be filled with a hot or cold medium and that said medium can contact said tip to heat or cool it; a hot medium making the pen a hot-pen and a cold medium making the pen a cold-pen; a hot-pen serving to cause an image to appear or disappear on said color memory temperature-sensitive layer by drawing the image on said layer to change the color state of the drawn portion into a first state; and a cold-pen serving to cause an image to appear or disappear on said color memory temperature-sensitive layer by drawing the image on said layer to change the color state of the drawn portion to a second state. BRIEF DESCRIPTION OF THE DRAWING Fig. 1 is a state diagram in which a color memory doll (soldier) is drawn with a hot-pen to cause a wounded soldier image to appear and then the wounded portion is again traced with a cold-pen to cause the wounded image to disappear; Fig. 2 is a longitudinal cross-sectional view of an example of a hot-pen; Fig. 3 is a transverse cross-sectional view taken along line A-A of Fig. 2; FIG.4 is a longitudinal cross-sectional view of an example of a cold-pen; FIG.5 is a front view of another example of a cold-pen; and FIG. 6 is an illustrative diagram of the color states of the color memory thermochromatic dye where the state changes in response to the change of temperatures, exhibiting hysteresis characteristics. DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described with reference to particular embodiment illustrated in the drawings (FIG.1 to FIG,6). A color memory toy according to this embodiment comprises a color memory toy 1, a hot-pen 2 and a cold-pen 3. The surface of the toy has a pattern and is provided with a color memory temperature-sensitive color changing layer 11 colored with a coloring material including a color memory temperature-sensitive dye exhibiting the hysteresis characteristics in response to temperature change between a colored state and a colorless state or between a color (I) and a color (II). The pens are used to draw an image on or mark the color memory temperature-sensitive color changing layer 11 so as to change the color of the drawn or marked portion so that the image or mark appears or disappears. At least one portion of the surface of the color memory toy 1 is preferably colored with a coloring material including a reversible color memory dye consisting of (a) an electron-supplying coloring organic compound, (b) an electron-accepting compound, and (c) an ester compound causing hysteresis characteristics, the color of which is changed with large hysteresis characteristics in response to temperature change. Lower color-changing temperature tl(°C) and higher color changing temperature t2(°C) of the dye are arbitrary selected from the temperature range of 0-50°C and are determined to satisfy the following equation: 5 ≦ t2-tl ≦ 35 (t2 > t1). One of two colors or a coexisting state of the two colors is arbitrary selected by chilling the colored portion below t1(°C) or heating it over t2(°C), and the selected color state can be maintained in the temperature range of t1 to t2 irrespective of the temperature change. Preferably, the lower color-changing temperature t1(°C) and the higher color-changing temperature t2(°C) should satisfy the following conditions: 5 ≦ t1 ≦ 23, and 24 ≦ t2 ≦ ≦40. A reversible thermochromatic color change composition disclosed in U.S. Patent No. 4,720,301 assigned to Pilot Ink Co., Ltd. is preferably used as the color memory temperature-sensitive dye. The aforementioned hysteresis characteristics means that the shape of a curve obtained by plotting changes in density of color is different between a case where the temperature changes from a temperature at lower side of a color-changing temperature range to a temperature at higher side of the color-changing temperature range and a case from high to low, so that a loop is formed when these two curves are combined. Assuming that a temperature of point "A" at which the two curves are joined at lower temperature side is t1(°C) (lower color-changing temperature), and a temperature of point "B" at higher temperature side is t2(°C) (higher color-changing temperature), temperature t1 of the color memory temperature-sensitive dye used in the present invention is in the range of 0 to 15°C, and temperature t2 is in the range of about 27 to 90°C. Also a dual-state coexisting temperature range (dual-color holding temperature range) of the dye, where both of the color state and the colorless state or both of the color (I) and the color (II) can coexist, is in the ordinary temperature range, especially in the range of 10-35°C (see Fig. 6). Further, the color memory temperature-sensitivity dyes may include those of different colors, those having the different dual-color temperature ranges within the normal temperature range, for example, a combination of two kinds of dyes in which the dual-color temperature range of one of the dyes is wider than that of the other and includes the narrower dual-color temperature range, and a combination of the color memory temperature-sensitive dyes having different hysteresis characteristics. Application of these dyes on the same surface or different surfaces of the toy respectively, can provide reversibility of a wide variety of patterns and designs. The aforementioned color memory temperature-sensitive color changing dye is dispersed in a suitable carrying-liquid or vehicle so as to be used as a coloring material in the form of ink, pigment, or paint, which is painted on a desired portion of the surface of the toy. Of course, the above-mentioned treatment may be applied on the surface of members of the toy before assembly thereof. In case that a base material is a thermoplastic material, the toy may be formed by mixing the plastic material with a thermochromatic material including the above coloring material. The color memory dye is preferably included in a microcapsule having a diameter of 0.5-50 µm, more preferably about 1-30 µm to form a microcapsule pigment. The microcapsule pigment is fixed to a binder in a dispersed state to form a painted layer. The percentage of the pigment in the layer is 5-80 weight %, more preferably 10-60 weight % in view of thermochromatic effect. If the percentage is less than 5 weight %, the color density is so low that the change of color is hardly seen. If the percentage is larger than 80 weight %, a clear colorless state is hardly seen. The thickness of the color memory temperature-sensitive color changing layer 11 is at least 0.5 µm, preferably 1-400 µm, more preferably 10-200 µm, in which a satisfactory color change effect is obtained. If the thickness is less than 0.5 µm, clear color change is not obtained. If the thickness is larger than 400 µm, the beauty of appearance is damaged. When the members of a toy are made of the thermoplastic material, the toy can be made by melting and molding the material mixed with the microcapsule pigment of 0.1-40 weight %, preferably 0.2-25 weight %, in which the color memory dye is included. The hot-pen 2 and the cold-pen 3 are used for heating or chilling desired portions to cause an image or a mark to appear or disappear. This is done by touching the pens to a color memory temperature-sensitive color changing layer 11 of the aforementioned color memory toy 1 to increase the surface temperature of the touched portion up to a temperature (higher than about 30°C but less than 90°C ) higher than the normal state or decrease it to a temperature (about 15°C) less than the normal state to thereby cause a change in color. These pens 2 and 3 do not have to be separate but may be made in such a way that one end of a bar-shaped body forms the hot pen and the other end a cold pen. The tip ends of the hot-pen 2 and the cold-pen 3 may take various shapes in accordance with a purpose. For example, they may take the form of a conical tip end, branching tip ends, a flat surface, or one in which the flat surface is formed into an image of a letter or a pattern. In the last one, the pens can be provided with a function of stamping in addition to a function of drawing. Also, the tip end of the pen may be provided with a plurality of small bosses on the surface thereof, may be shaped into a comb configuration, or may be provided with a brush-like member. The hot-pen 2 and the cold-pen 3 may be made of any writing material that meets the aforementioned temperature conditions. The pens can also be of a construction in which the tip end portion of a pipe-like member is formed in the shape of increasingly smaller diameter and to close at the end as a writing-tip while the rear large diameter portion is filled with hot or cold heat medium. A specific example of the construction of the hot-pen and the cold-pen which is simple in use and allows the function of drawing to last for a relatively long time, will now be described as follows. The hot-pen 2 may be of a construction that a pen body 21 at least the tip end portion of which is made of a metal is supported at one end of a barrel 22 while also being in contact with a heat medium 23 that conducts heat. Although the heat medium 23 can be filled directly in the barrel 22, an inner pipe 24 connected to the pen body 21 may be disposed within the barrel 22 to receive the heat medium 23 therein, thereby preventing leakage of heat or danger that may be caused by heat when a user grips the barrel 22 as well as allowing the pen to effectively function in terms of maintaining chilled condition. The heat medium 23 may be not only warm or hot water but also a solvent having a high boiling point, sand, or metal powder, which is heated to a high temperature. The inner pipe 24 may be provided to extend behind the pen body 21 integrally therewith. The cold pen 3 may be arranged by filling ice or cold water, instead of the heat medium 23, in the barrel 22. The barrel or the writing tip end of the hot-pen 2 or the cold-pen 3 may be provided with a reversible thermochromatic layer to indicate a temperature so that whether the pen is in the suitable temperature range, can be seen. Drawing on or marking the color memory temperature-sensitive color changing layer 11 with the hot-pen 2 or the cold-pen 3 will heat or chill the drawn or marked portion to cause color change, thereby shifting into a stage different from that at normal temperatures (from a colorless state to a colored state or vice versa, or from a color (I) to a color (II) or vice versa) and thereafter retaining the state for the drawn image or mark to be seen. Drawing on or marking the previously drawn image or mark with a counter pen i.e., the cold-pen 3 for the hot pen and the hot-pen 2 for the cold pen 3, will cause the portion to change its color to that of the previous state (the state before the initial drawing or marking) so that the drawn image or mark is erased (unseen state). This change in stage is repeatable. Specific examples of the hot-pen and the cold-pen will now be described as follows. Example 1 (see FIG. 2 and FIG. 3) The hot-pen 2 comprises a bullet-shaped pen body 21 formed integrally with an aluminum inner pipe 24 (0.3 mm thick, 10 cm long) of a diameter of 11 mm, the diameter of one end of which is decreased in step wise to form the pen body, a barrel 22 (0.3 mm thick, 15 mm outer diameter) of polypropyrene resin including the inner pipe therein, and a tail cap 25 (beads 251 are provided at three locations on the inner wall of the cap so as to support the rear portion of the inner pipe 24) fitted to the barrel. The writing-tip end portion is provided with a reversible thermochromatic layer 26 that exhibits red at temperatures higher than 35°C and deep green at temperatures less than 20°C). Hot water of about 60°C is filled in the inner pipe 24 immediately before the pen is used. Example 2 Fine sand is filled instead of hot water in the aforementioned inner pipe 24. The writing tip end portion is regulated to become a temperature of about 60°C shortly after assembly. In assembly procedure, the inner pipe 24 (including the pen body 21) retained with the tail cap 25 is heated with the fine sand being filled, then the tail cap 25 is pinched to insert the pipe into the barrel 22. Example 3 (see FIG. 4) A cold-pen 3 is obtained by fixing a pen body 31 made of a metal hollow body, a front end of which is closed, in a holding member 311, then fastening the member 311 to a plastic barrel 32 filled with cold water or pieces of ice. Example 4 (see FIG. 5) A cold-pen 3 is obtained by attaching an attached member 34 having small bosses 341 to the tip end of the pen body 31 of Example 3. Example 5 A cold-pen 3 is obtained by filling cold water (about 5°C) instead of hot water into the pen of Example 1. Examples 6 and 7 Hot-pens 2 are obtained by filling hot water (about 60°C) instead of the cold water into the pens of Examples 3 and 4, respectively. Examples 8 and 9 Instead of the pen body 21 of Example 1 or the pen body 31 of Example 3, a pen body of a plastic hollow body having a thin wall, the tip end of which is shaped into a bullet, is attached, respectively to form a hot-pen 2 or a cold-pen 3. Example 10 A pen body 21 or 31 is formed of a plastic hollow body having a closed tip end, in a side wall of which metal pieces are inserted, which is attached to the end of a barrel filled with hot water or cold water, so that a cold pen 2 or a hot-pen 3 is obtained. The side wall (metal surface) is touched to perform the function of drawing. Embodiment 1 Two pigments were made, one including a color memory temperature-sensitive dye which changes the color between deep green and red (t₁: 10°C, t₂: 32°C) and the other including a color memory temperature-sensitive dye which changes the color between brown and red (t₁: 10°C, t₂: 32°C). A color memory doll 1 of a soldier was obtained by spraying the former pigment on a helmet, a uniform jacket and a uniform pant, and spraying the latter pigment on a pair of gloves and boots, and then drying. The doll was in green and brown in a normal temperature range. This doll was played with by drawing, with the hot-pen 2, patterns of wound on a shoulder, an arm, and a leg of the "soldier" to change the color of the drawn image 4 to red, thus changing the doll to a "wounded soldier". Then, tracing the "wounded" part by using the cold-pen 3 caused the red to disappear and return to the previous deep green and brown. The soldier returned to the previous non-wounded condition. Drawing again a pattern of a wound on his back by using the hot-pen caused that part to change to red, thereby changing the soldier to a soldier who was wounded on his back. Embodiment 2 A pattern of a business suit was printed on the clothes of a doll using ink, color of which would not change (i.e., ordinary pigment ink), and then a pattern of a battle dress was printed over the previous "business suit" using a color memory temperature-sensitive dye reversible between deep green and colorless state (t₁: 15°C, t₂: 32°C), thereby completing a color memory doll. This doll was arranged so that the pattern of the deep green battle dress is observed in a normal temperature range. Drawing on the pattern of the battle dress caused a pattern under the drawn portion to appear, and further drawing on all the battle dress pattern caused the business suit pattern to be observed. Then, drawing on the business suit pattern with the cold-pen 2 caused the deep green image to be observed and further drawing on all the pattern caused the business suit to turn out to be the battle dress. Embodiment 3 A metal miniature car was made to have a dual appearance body by spraying a pigment containing a color memory temperature-sensitive dye reversible between red and yellow (t₁: 18°C, t₂: 32°C) to the surface of the car. The body was retained to be red in a normal temperature range. The upper half of the body was painted by the hot-pen 2 to cause it to change to yellow, thus allowing the miniature car to be changed to a car of two-tone color of red and yellow. Then the surface of the yellow body is painted by the cold-pen 3 to cause the yellow part to change to red, thereby allowing the body to return to the previous appearance. This change in appearance was obtained with good repeatability through repetitive operation so that the car can be repeatedly played with. Embodiment 4 The surface of a white miniature car was printed to make a dotted line on its side surface and letters on its roof by using ink containing a color memory temperature-sensitive dye reversible between black and colorless (t₁: 15°C, t₂: 35°C). The miniature car was then dipped into warm water of about 40°C and was then taken out, thus being set to be in invisible state in which the printed images disappeared in a normal temperature range. Drawing on the printed image portion by using the cold-pen 3 caused a black dotted line and the letters to appear. Then tracing the same image by using the hot-pen 2 caused the image to disappear, allowing the car to turn out to be the white miniature car. Embodiment 5 The surface of a white miniature car was painted to have its yellow body observed at a room temperature (22 to 33°C) by spray-painting a spray ink that was made by mixing a color memory temperature-sensitive dye reversible between blue and colorless (t₁: 13°C, t₂: 30°C), a color memory temperature sensitive dye reversible between pink and colorless (t₁: 20°C, t₂: 36°C), and a yellow pigment, color of which would not change. The lower half portion of the car was painted by using the cold pen 3 to cause it to change to brown (this state was retained at a room temperature of 15-27°C). Then, warming the miniature car by hands caused the lower half portion to change to pink, which was retained at a room temperature of 15 to 33°C. Thereafter, drawing a letter (A-1) on the lower half portion by using the hot-pen 3 caused the white drawn image to appear. Then painting the upper half portion by using the cold-pen caused that portion to change to a brown state which was retained at a room temperature (15 to 27°C). When the miniature car was again dipped into warm water of 40°C, the white miniature car again appeared. Additionally, the entire body of the miniature car was chilled by ice water or the cold-pen to set the entire car body to brown, and the same operation was repeated. The miniature car exhibited the same color change, thus allowing the user to repetitively play with the car. Embodiment 6 Flower pattern was printed on a piece of polyester cloth of light blue by using ink of yellow and light green that would not change in color, and then the entire cloth including the flower pattern was screen-printed by using a printing ink containing a color memory temperature-sensitive dye reversible between red and colorless (t₁: 15°C, t₂: 32°C). A dress was made from the thus printed cloth. This dress was put on a doll made of polyvinyl chloride resin thus making a color memory doll. The hair portion of the doll was formed by planting nylon filaments. A color memory temperature-sensitive color changing material reversible between brown and silver (t₁: 15°C, t₂: 35°C) was blended in the respective filaments. The cloth of the doll was set such that the flower pattern in a background of the light blue was seen, and the hair portion was retained in silver in a normal temperature range. Drawing letters or patterns on the surface of the cloth of the doll by using the cold pen 3 caused the drawn portion to immediately change to red, thereby allowing observation of the image. Also, drawing entirely the printed flower pattern by using the cold-pen 3 caused the flower pattern to change to red so that the flower pattern is hidden to be invisible. Drawing on the hair portion by using the cold-pen 3 caused the drawn filaments to change to brown. This state was held in a normal temperature range. Tracing the color-changed parts of the cloth and hair by using the hot-pen 2 caused these parts to return to their original states. The change in state was repeatedly obtained through repetitive operation, allowing the user to play by drawing on any appropriate portion of the doll to cause the images to appear or disappear. Embodiment 7 A pigment containing a color memory temperature-sensitive dye was applied to a little white plastic house, a chair, and a table which had been painted with a white pigment having no color-changing property (general pigment ink), thereby forming a color memory toy. In more detail, the roof portion was painted with a pigment reversible between deep green and red (t₁: 13°C, t₂: 32°C), the wall portion was painted with a pigment reversible between yellow and colorless (t₁: 13°C, t₂: 32°C), the floor portion was painted with a pigment reversible between brown and light brown (t₁: 13°C, t₂: 32°C), and the chair and the table were painted with a pigment reversible between brown and colorless (t₁: 13°C, t₂: 32°C), thus providing a color memory temperature-sensitive color changing layer. At a room temperature, the roof was in red, the wall in white, the floor in light brown, and the chair and the table in white. The respective parts mentioned above were drawn by the cold-pen 3 to cause letters and patterns to appear, or drawing on all the surface of the respective parts caused color change of the roof into deep green, the wall into yellow, the floor, chair, and table into brown. The aforementioned drawn image and the state of the surface could be erased and returned to the original state by tracing the same portion by the hot-pen 2. As described above, a user can freely draw a desired image on or mark the surface of a color memory toy by a hot-pen or a cold-pen to cause the image or mark to appear and to be seen. Further, the user can easily erase the image by using the pens into the original state. Thus, the toy provides the user with various playing ways as a toy exhibiting various states. Accordingly, with the addition of the characteristics of the color memory toy, the color memory toy set provides such a toy with a high additional value and enhances the value of the toy as a commodity. Also, since drawing and erasing of the image by the pens can be conducted without using coloring components, there is no fear of polluting clothes, not to speak of the drawn surface, so that a child, a school child or the like can safely use it.

Claims: A color memory toy set, comprising: a color memory toy having a surface of a pattern, at least one portion of said surface being provided with a color memory temperature-sensitive color changing layer colored with a coloring material including a color memory temperature-sensitive dye exhibitiging hysteresis characteristics in response to temperature change between a colored state and a colorless state or between a first color (I) state and a second color (II) state; one or more pens, each pen comprising a barrel (22, 32) having a closed tip (21, 31) serving as a writing tip and the arrangement being such that said barrel can be filled with a hot or cold medium (23, 33) and that said medium can contact said tip (21, 31) to heat or cool it; a hot medium making the pen a hot-pen and a cold medium making the pen a cold-pen; a hot-pen serving to cause an image to appear or disappear on said color memory temperature-sensitive layer by drawing the image on said layer to change the color state of the drawn portion into a first state; and a cold-pen serving to cause an image to appear or disappear on said color memory temperature-sensitive layer by drawing the image on said layer to change the color state of the drawn portion to a second state. A color memory toy set as in Claim 1 wherein said tip is of metal. A color memory toy set as in Claim 1 or Claim 2 and wherein a hot-pen comprises within said barrel (22) an aluminium inner pipe (24) having a closed tip end (21) extending beyond said barrel, said inner pipe (24) serving to accommodate said hot medium. A color memory toy set as in Claim 3 and wherein the end of the barrel (22) remote from said tip (21) and the end of said inner pipe (24) remote from said tip (21) is closed by a removable tail cap (25) (Fig. 2). A color memory toy set as in Claim 1 or Claim 2 and wherein a cold-pen comprises a barrel (32) of plastics material closed at its front end by a holding member (311) for said tip (31) (Fig. 4). A color memory toy set as in Claim 5 and wherein said holding member (311) is removable from said barrel (32) to permit the cold-pen to be filled with cold water or pieces of ice. A colour memory toy set as in Claim 5 or Claim 6 having a member (34) formed with small bosses (341) attached to the tip (31) of the pen. A color memory toy set as in Claim 1 and wherein said pen is so constructed that that one end forms a hot-pen and the other end a cold-pen. A color memory toy set as claimed in Claim 1, wherein said color memory temperature-sensitive dye includes (i) an electron-supplying coloring organic compound, (ii) an electron-accepting compound and (iii) an ester compound causing the hysteresis characteristics, wherein a lower color-changing temperature t₁ (°C) and a higher color-changing temperature t₂ (°C) of said dye are arbitrarily selected from the temperature range of 0-50°C, and are determined to satisfy the following equation: 5≦ t₂ - t₁≦ 35 (t₂> t₁ ), wherein one of the color states or a coexisting state of the two color states is arbitrarily selected by chilling said color memory temperature-sensitive color changing layer below t₁(°C) or heating said layer over t₂(°C), and wherein the selected state is maintained in the temperature range of t₁ to t₂ irrespective of the temperature change.

Inventors: KITO TSUTOMU, NAKASUJI NORIKAZU, SHIBAHASHI YUTAKA, KITO, TSUTOMU, NAKASUJI, NORIKAZU, SHIBAHASHI, YUTAKA
Applicants: PILOT INK CO LTD, THE PILOT INK CO., LTD.
Application year: 1990
Main classification: A63H33
IPC codes: A63H33, B41M5, B43K29, B43K19, B43K8