JPH076959Y2 - Electric heating tool - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electric heating tool. More specifically, the present invention relates to an electric heating tool such as a toy, a picture book, and a learning material having a thermochromic layer formed on the surface thereof, which heat-discolors a contact portion by contacting the thermochromic layer.

2. Description of the Related Art Conventionally, an electric heating tool for contacting a color-changing material formed on the surface of an animal toy or the like and changing the color of the contact portion is
It is disclosed in Japanese Utility Model Laid-Open No. 62-139573 and Japanese Patent Laid-Open No. 62-201178.

The toy described above is characterized by a structure in which a metal-based resistance heating element such as tungsten, nickel, or titanium is used, and the heating portion is covered with an insulating material such as ceramics.

Problems to be Solved by the Invention In the above-described conventional electric heating tool, the heating element itself does not have a self-temperature control function that effectively functions within the toy-appropriate temperature range. In addition to requiring switches and the like, insulation treatment such as coating of the heat generating portion with ceramics or the like was necessary to avoid the risk of leakage.

The heating device according to the present invention eliminates the above-mentioned danger due to overheating or energization, quickly raises the heating element to a desired heating temperature by applying a low voltage, and the fluctuation of the heating temperature due to the change of the outside air temperature. An attempt is to provide a convenient and safe energizing heating device that constitutes a small number of heating tools, writes or stamps on the thermochromic layer of an object, discolors the thermochromic layer, and makes a desired handwriting or image visible. To do.

Means for Solving the Problems The present invention will be described with reference to the drawings.

The present invention's electric heating tool 1 is an electric heating device that heat-discolors a contact portion of a toy, a picture book, a learning material, etc., on which the thermochromic layer 8 is provided on at least a part of the surface thereof, by heating the thermochromic layer 8 to contact the thermochromic layer 8. In the tool, an electric heating element 3 housed in the main body 2
In the temperature range of 25 ° C. to 70 ° C. of the electric heating element 3 in the temperature range of 25 ° C. to 70 ° C. This is a resistance heating element with a positive coefficient, and (b) the volume resistivity (ρ ₂₅ ) at 25 ° C is 9.8 × 10 ^-3 Ω.cm to 2.97 × 10 ⁵
Ω.cm, (C) The ratio (ρ ₇₀ / ρ ₂₅ ) of the volume resistivity at 25 ° C and 70 ° C is within the range of the following formula 5 ≦ (ρ ₇₀ / ρ ₂₅ ) ≦ 400. , 0.8 V to 40 V are applied to generate heat, and the heat generation saturation temperature is constituted by a thermistor self-temperature controlled to an arbitrary temperature within a temperature range of 25 ° C. to 70 ° C.

In the above, the energization heating element 3 having a size of approximately 0.05 cm ^{2 to} 30 cm ² (area on one side) and a thickness of 0.05 cm to 1.0 cm has practicality as a heating element for a toy, and is within the above range. The heating element 3 having an appropriate size can be applied in combination.

A system having a smaller area has less discoloring effect and is not suitable as a toy element.On the other hand, a system having a large area and a large volume is preferable in terms of heat generation in a short time by applying a low voltage, heat generation efficiency, soaking property, etc. Absent.

The heating element 3 is a BaTiO ₃ system sintered body [semiconductor doped with a rare earth element and further substituted with an element such as Sr, if necessary,
Examples include Si single crystal type and organic plastic type (low melting point crystalline plastic blended with conductive fine powder such as graphite) in a low temperature range (25 to 70
From the aspects of adjusting the heat generation saturation temperature at
A BaTiO ₃ based sintered body is suitable.

The heating element 3 has a disc shape, a band shape, a honeycomb shape, and the like.
An appropriate shape is adopted according to the purpose.

Next, the characteristics of the electric heating element 3 applied to the present invention are shown in FIG.
The graph shown in FIG. 7 will be described.

It is essential that the energization heating element 3 has a positive temperature coefficient of electric resistance within a range of at least 25 ° C to 70 ° C, and that the resistance value increases steeply with temperature rise (the fourth requirement). (Fig.), And the amount of heat generation sharply decreases due to the rapid increase in the resistance value within the temperature range, enabling self-temperature control within the temperature range.

Furthermore, the heating element 3 has a volume resistivity (ρ ₂₅ ) at 25 ° C of 9.
8 × 10 ^-3 Ω.cm to 2.97 × 10 ⁵ Ω.cm, more specifically, the volume resistivity (ρ) at each temperature is within the permissible range shown in FIG. 5 (range of lines showing upper and lower limits). The ratio of volume resistivity at 25 ° C and 70 ° C (ρ ₇₀ / ρ ₂₅ ) is
The requirement is that (ρ ₇₀ / ρ ₂₅ ) ≦ 400.

By satisfying the above requirements, it is possible to supply the heating element 3 that satisfies the heat-generating property in the low temperature range (70 ° C., preferably 50 ° C. or less) required for the toy element and the self-temperature controllability. In a system in which the heating element 2 is out of the limit value at each temperature, for example, in a system having a volume resistivity exceeding the upper limit line, unless the voltage is increased,
It is difficult to raise the temperature to the desired temperature range in a short time, and in a system with volume resistivity lower than the lower limit line, the desired heat generation temperature cannot be obtained unless the voltage is extremely low and large radio waves are sent. , Has no practicality as a toy element.

FIG. 6 is a graph showing the relationship between the stable temperature of the heating element due to room temperature change, and the object to be heated is stable at a temperature at which the amount of heat generated by the heating element per unit time and the amount of heat radiation (per unit time) match. However, the heating element 3 applied to the present invention is less affected by the ambient temperature and exhibits stable thermal characteristics as compared with the metallic heating element system. FIG. 7 is a graph showing the relationship between the energization heat generation time and the heat generation temperature of the heating element. The above experimental data is based on the BaTiO ₃ system sintered body [15.0 mmφ × thickness 1 mm, 2.5 Ω (25
(° C) as a heating element 3 and a wiring of titanium wire (formed on a 0.1 mm polyester film) as a metallic heating element was tested for comparison, and each was 30 mm square × thickness 0.3 mm.
It was obtained by applying a voltage of about 1 V to a brass plate of the above.

It is effective to provide an electrode 7 on the energization heating element 3 in terms of energization assembly processing. Specifically, the facing surface of the energization heating element 3 itself is plated with aluminum sprayed nickel, tin or the like. Can be formed on the heat transfer member 4 or formed on the heat transfer member 4 in contact with the electric heating element 3.

The heat transfer member 4 is not limited to a metal material, and may be thin heat conductive rubber, plastic, ceramics, or the like.

The electrode 7 is provided on the opposite surface of the electric heating element 3, one electrode 7 can be provided on the back surface of the electric heating element 3, and the other counter electrode can be provided on the front surface of the heat transfer member 4 (conductive member). .

A power source 10 is connected to the electrode 7 through a conductive member such as a lead wire 6.
It is set so that it can be energized. As the power supply 10, various batteries and commercial power supplies are applied after being adjusted to a predetermined voltage (0.8 to 40 V).

The power source 10, for example, a battery or the like, can be detachably housed in the main body to form an electric heating tool, but can be configured to be able to be energized by a power source outside the system.

It should be noted that a reversible thermochromic display that changes color in accordance with the heat generation temperature is provided at an appropriate position on the tip of the main body 2 for convenience of use.

The object to which the electric heating tool 1 of the present invention is applied is effectively an object having a toy, a picture book, a learning material, a fortune telling, a game element, etc., on which a thermochromic layer is provided on at least a part of the surface.

The thermochromic layer 8 in the above is a conventionally known thermochromic material,
For example, a thermochromic material containing three components of a liquid crystal, an electron-donating color-developing organic compound, a developer of the compound, and a compound serving as a medium for causing a color reaction of the both, or a resin solid solution of the component. Thermochromic materials exhibiting reversible thermochromic properties in the form of fine particles (for example, JP-B-51-35414 and JP-B-5).
1-44706, Japanese Patent Publication No. 52-7764, Japanese Patent Publication 1-29
No. 398, JP-A No. 60-264285, and other thermochromic materials disclosed in JP-A-60-264285.
Systems with a discoloration point at ~ 50 ° C) are applicable.

Among the thermochromic materials described above, the dye according to JP-A-60-264285 has a hysteresis characteristic, that is, the shape of a curve plotting the coloring density due to temperature change changes the temperature as shown in the graph of FIG. Unlike the case of changing to the low temperature side from the temperature range, it has a characteristic that when both curves are combined, it becomes a loop shape, discolors at a heating temperature of t ₂ or more, and the aspect that has discolored once even without applying heat. The electric heating tool 1 of the present invention has a color memory property that is stored and held in a room temperature range.
Can be used in combination with an object having a thermochromic layer 8 composed of a coloring material containing this type of dye, and can be applied as a set with a cold heat pen to enhance the effectiveness. That is,
By cooling the thermally discolored appearance to a temperature not higher than t _1, it can be converted to the appearance before the discoloration, and can function as a paired pen.

By applying a working voltage, the energization heating element 3 is caused to generate heat, the temperature of the heat transfer member 4 arranged in contact with the heat generating element 3 is raised, and the heat transfer member 4 is heated.
Alternatively, the covering member 5 of the member is heated and heated.

When a voltage is applied, the energization heating element 3 self-heats and rises in temperature,
Along with this, the resistance value rapidly increases, the temperature rise rate decreases, and the self-temperature control is stably performed at a temperature at which the heat generation amount and the heat radiation amount match (see FIG. 6).

Looking at the relationship between the elapsed time after energization and the heat generation temperature, the heat generation amount per unit time due to temperature rise is almost constant due to the fact that the system of the metal heating element has a very small resistance change rate due to temperature, and the temperature slowly changes. On the other hand, in the energization heating element 3 of the present invention, a large current flows immediately after energization, the temperature rise rate is large, and the temperature rapidly rises to a predetermined temperature.

With respect to changes in room temperature, the energization heating element 3 is stable at about 33 ° C when the ambient temperature is 20 ° C, is stable at about 38 ° C when the ambient temperature is 28 ° C, and the difference is about 5 ° C. , In the system of metal heating elements, the stable temperature is about 32 ° C when the ambient temperature is 20 ° C, and the stable temperature is 39 ° C when the ambient temperature is 28 ° C, due to the small change in the calorific value per unit time depending on the temperature. As shown by the experimental data of the temperature difference of 7 ℃, the current-carrying heating element 3 of the present invention
Shows a behavior in which the temperature change due to the ambient temperature is smaller than that of the system of the metal heating element.

The current-carrying heating element 3 exhibits the above-described behavior when a low voltage (0.8 to 40 V) is applied by satisfying the requirements (a), (b), and (c), and a low temperature range (70 ° C. or lower). Plays a self-temperature control function and develops the desired thermal characteristics.

The covering member 5, which is provided as necessary, can be made to function so that the touch on the contact surface can be made smooth and a desired handwriting can be appropriately provided. Furthermore, it contributes to give a sharp impression by giving appropriate elasticity.

The current-carrying heating tool 1 of the present invention is set to a temperature at which an object whose thermochromic layer 8 has a color changing point of 20 to 60 ° C. can be discolored, and heat-discolors to an appearance different from the appearance at room temperature.

Example 1 A heat transfer member 4 having a pen tip portion projecting from the axis of a flat portion was joined to a front end opening of a main body 2 made of a plastic barrel, and a back surface of the flat portion was joined with a conductive adhesive. Heating element 3 [BaTiO ₃ system sintered body (15 mmφ × thickness 1 mm, conductive plating layer is formed on both sides, resistance value 2 Ω (25
The heat generating element in which the resistance heat generating element whose heat generation saturation temperature is set to 45 ° C.) is integrated is arranged, and two 1.5 V dry cells are arranged in series and provided on the front surface of the flat surface of the heat transfer member 4. The energization heating tool 1 was constructed by setting the electrodes 7 and the conductive member so that they could be energized (Fig. 8). The power switch section is provided at an appropriate position (not shown).

In the heating tool 1, the temperature of the nib portion was raised to about 45 ° C. after 30 seconds at room temperature of 25 ° C. after energization.

Example 2 A heat transfer member 4 [aluminum plate (60 mm × 30 mm × thickness 1 mm)] is provided on the inner bottom surface of the main body 2 made of a plastic outer shell, and a conductive adhesive is provided on the back surface thereof in series at appropriate intervals. Heat generators _{3 of the} same shape and size [Each is a BaTiO ₃ system sintered body (15
mmφ × thickness 1 mm, conductive plating layers are formed on both sides, consisting of a resistance heating element with a resistance value of 2.5 Ω (25 ° C) and a saturation temperature of 45 ° C.] The heating element (third electrode) in which the electrode 7 on the back surface of the body 3 and the electrode 7 on the surface of the heat transfer member 4 are wired in parallel by the lead wire 6 (third embodiment)
(See the figure) is arranged and set so that energization and heat generation can be achieved by applying a voltage of 3 V, and the iron-type energization heating tool 1 is configured (first
0).

The bottom surface (the portion exposed on the surface) of the heat transfer member 4 may be surface-coated with a fluorine-based resin or a silicon-based resin to impart lubricity during use. or,
A reversible thermochromic display for confirming the exothermic temperature can be appropriately provided.

Application Example 1 A picture book for infants in which the answer element is hidden by the reversible thermochromic layer 8 [a banana pattern and characters (non-color-changing layer 9) are formed by printing with a yellow non-color-changing ink, and the non-color-changing layer 9 is formed. Covers, has a discoloration point at 40 ℃, shows a green color below 40 ℃
The reversible thermochromic layer that erases color is overprinted.]
When the heating tool 1 in the elevated temperature state of Example 1 was applied to the surface of the thermochromic layer 8 and the surface of the thermochromic layer 8 was written, the layer 8 was decolored and the non-color-changing layer 9 was exposed, and the answer was discriminated. (See Figures 12 and 13). At room temperature, the non-color-changing layer 9 returned to the concealed state.

Application Example 2 Doll clothes having a thermochromic layer 8 colored with a color material containing a color-memory thermosensitive pigment [a light blue plain cloth with a floral pattern (non-color changing layer 9) formed of yellow and light green) cage, entirely red colorless containing the non-color-changing layer _{9 (t 1: 15 ℃,} t 2: 32
Is covered with a thermochromic layer 8 that changes to (° C.) so that red clothes can be seen in the normal temperature range], and the iron-type heating tool 1 (temperature rising state) is applied to When it was applied, the contact points were immediately erased, and the entire surface was ironed to reveal the floral pattern on the pale blue background, and the appearance was stored in the normal temperature range and stored for visualization.
(See Figures 10 and 11).

Effect of the Invention The current-carrying heating tool of the present invention can rapidly heat the current-carrying heat-generating layer by applying a low voltage to raise the temperature to a predetermined temperature to change the color of the thermochromic layer. Since there is self-temperature control at the exothermic saturation temperature of, there is no danger due to overheating.

Further, since it is an energized heat generation system by applying a low voltage, there is no danger of leakage, and it is of course not necessary to coat the heater part to prevent the danger, and it can be safely used by infants and the like. it can.

Further, various commercially available batteries can be applied as the power source, and a convenient and portable energization heating tool to which a dry battery or the like is detachably attached can be provided.

Furthermore, the tip part (contact surface to the target surface) of the heating tool of the present invention is
It is also effective to provide an image such as a character and a pattern as well as an appropriate shape and size, and the thermochromic layer can be variously changed, which satisfies the practicality. In addition, if it is a set product that is combined with a cooling / heating device (which is configured to cool the contact surface with ice chips and cold water built-in), the color-changing effect of the thermochromic layer can be effectively exhibited. , Together with satisfying safety, can be applied in various ways.

[Brief description of drawings]

1 to 3 are vertical cross-sectional views illustrating an embodiment of an electric heating tool of the present invention, and FIGS. 4 to 7 show characteristics of an electric heating element applied to the electric heating tool of the present invention. FIG. 4 is a graph, FIG. 4 shows characteristics of temperature and resistance, FIG. 5 shows an allowable range of volume resistivity at each temperature, FIG. 6 shows a relationship of stable temperature of a heating element due to room temperature change, and FIG. The relationship of the exothermic temperature of the exothermic body is shown respectively. FIG. 8 is a vertical sectional view of an embodiment of the electric heating tool of the present invention,
FIG. 10 is a perspective view of the main part of the tip of another embodiment, FIG. 10 is an explanatory view of a state in which a doll garment provided with a thermochromic layer is discolored by using the electric heating tool of the present invention, and FIG. 11 is A state diagram in which the doll clothes are discolored to reveal other aspects, FIG. 12 is a picture book in which a non-color-change image is hidden by a thermochromic layer, and FIG. 13 is a non-color-change image in which the concealed portion of the picture book is changed in color. FIG. 14 is a graph showing a thermochromic characteristic of the color memory sensitizing thermosensitive dye. DESCRIPTION OF SYMBOLS 1 ... Electric heating tool 2 ... Main body 3 ... Heating element 4 ... Heat transfer member 5 ... Covering member 6 ... Lead wire 7 ... Electrode 8 ... Thermochromic layer 9 ... Non-color-change image 10 ... Battery

Claims (2)

[Scope of utility model registration request] 1. An electrically conductive heating tool, such as a toy, a picture book, and a learning material having a thermochromic layer provided on at least a part of its surface, which heat-discolors a contact portion by contacting with the thermochromic layer. A structure for causing an energizing heating element contained therein to generate heat and heating a heat transfer member arranged in contact with the heating element to function, wherein the energizing heating element (a) has an electric resistance in a temperature range of 25 ° C to 70 ° C. Is a resistance heating element showing a positive temperature coefficient, and (b) the volume resistivity (ρ ₂₅ ) at 25 ° C is 9.8.
× 10 ^-3 Ω.cm to 2.97 × 10 ⁵ Ω.cm, (C) The ratio (ρ ₇₀ / ρ ₂₅ ) of the volume resistivity at 25 ° C and 70 ° C is expressed by the following formula 5 ≦ (ρ
₇₀ / ρ ₂₅ ) ≤ 400, satisfying the respective requirements, heat is generated when a voltage of 0.8 V to 40 V is applied, and the heat generation saturation temperature self-heats to any temperature within the temperature range of 25 to 70 ° C. An electric heating tool composed of a thermistor whose temperature is controlled. 2. The electric heating tool according to claim 1, wherein the heat transfer member is a metal member, and the surface of the member is covered with a heat conductive silicon rubber or a plastic thin film.