JP2006257186A - Thermopaint and thermosensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems of the conventional seal-like thermosensor widely used in many industrial fields that need temperature control, problems that when a heat-melting organic compound, namely a thermosensitive substance, turns into a liquid, sucking-up paper to suck up this is necessary and that heat conductivity worsens because this sucking-up paper is interposed, the number of parts increases to raise the indwelling possibility of causing malproduction in the production process and so forth. <P>SOLUTION: The thermopaint is obtained by uniformly mixing in a solvent a powdered heat-melting organic compound that melts at an optional set temperature set in advance, a filler consisting of fine particles of indeterminate form and a thickening agent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a paint having a temperature indicating action and a temperature sensing body using the paint, and more specifically, a special paint that performs irreversible temperature indication by making it transparent when reaching an arbitrary preset temperature and the same. It relates to a temperature sensor.

  The temperature sensor in the form of a seal can be easily applied to the desired part of various devices, can be applied to narrow spaces, and does not require a power source. Widely used.

When the temperature reaches a preset temperature, the fact is displayed by color development, and even if the temperature of the object to be measured returns below the set temperature, the same display is displayed. There is a reversible temperature sensor that changes the display according to the temperature change of the body and the object to be measured, but the irreversible temperature sensor is an unmanned device installed in a remote place or periodically every fixed period It is widely used for temperature control of equipment that needs to be checked.
JP 2001-83020 A None.

  There are various types of coloring mechanisms of this irreversible temperature sensor, but the mainstream ones are absorption paper and colored paper coated with a melting substance such as wax that melts at a preset specified temperature. Is superimposed so that the colored surface of the colored paper, which has not been shielded from the outside by the melting phenomenon of the molten material, can be seen through. FIG. 1 is a representative example of this type of temperature sensor currently mainly produced, and an absorbent paper 2 coated with a melting substance such as wax that melts at a preset temperature is pasted on a substrate 1. Further, the colored paper 3 is superimposed on the absorbent paper 2 with the chromatic surface 4 facing the absorbent paper 2, and the entire surface side is covered with the transparent film 6. In this temperature sensor, the chromatic surface 4 of the colored paper 3 is located on the back side and is normally not shielded and visible. However, when the temperature reaches a preset temperature, a melting substance such as wax applied to the absorbent paper 2 is melted. However, the color was developed by soaking in the colored paper 3 and making it transparent so that the colored surface 4 that was not visible until then could be seen through from the surface side, that is, from above.

  As described above, the conventional temperature sensing element is configured by combining the absorbent paper 2 and the colored paper 3, and therefore, a minimum thickness corresponding to the total thickness of the absorbent paper 2 and the colored paper 3 is necessary. There was a problem in heat conductivity because heat was not easily transferred from the temperature measurement object to the temperature sensitive substance. In addition, since the absorbent paper 2 and the colored paper 3 are combined, the production is troublesome, and there is a possibility that the combination is wrong in the manufacturing process and a defective product is produced.

  On the other hand, if the temperature indicating agent that melts at a specific temperature can be directly attached to the colored paper 3, the absorbent paper 2 is not necessary, so that the thickness can be reduced by that amount, the thermal conductivity is improved, and the manufacturing is easy. It is clear that the possibility of defective products due to manufacturing mistakes is also reduced, but the conventional temperature indicating agent has poor adhesion, and it is very difficult to stably adhere to the colored paper 3 and peels off during use. Due to the nature of the temperature sensor, which places great importance on reliability, it cannot be said that it can withstand practical use.

  As a result of researches to solve the above-mentioned conventional problems related to the temperature sensor having a seal shape, the present inventor has found that the temperature of the seal shape has been reduced without using absorbent paper, which is essential in the conventional temperature sensor. We have succeeded in developing an innovative temperature indicating paint that not only can realize a sensing object but can also be applied directly to a temperature measurement object. This is what we propose.

  A temperature-varying paint is formed by uniformly mixing a heat-fusible organic compound powder that melts at any preset temperature, a filler made of irregular fine particles, and a polymer resin that has a binding action in a solvent. The above problem was solved. The temperature sensitive layer 5 made of the temperature indicating paint is formed on the chromatic surface 4 of the colored paper 3 to form a seal-like temperature sensor. Further, the temperature sensitive layer 5 made of the temperature indicating paint is directly formed on the predetermined portion 7 of the temperature measurement object 8 where the temperature is to be measured.

  When the temperature indicating paint according to the present invention is used, no absorbent paper is required, and it can be applied directly to colored paper or a temperature measurement object. Can be manufactured. In addition, since it is not necessary to use absorbent paper, the thermal conductivity is better than that of the conventional paper, and the temperature sensing accuracy can be improved. Furthermore, the seal-like temperature sensor can be made thinner, and can be installed even in a small gap that cannot be installed in the conventional one. In addition, since it is applied directly to colored paper or a temperature measurement object, there is no risk of wrong combination of absorbent paper and colored paper in the manufacturing process, and there is no risk of defective products. Furthermore, it is possible to directly form the temperature sensitive layer on the surface of the temperature measurement object.

  The greatest feature is that the heat-fusible organic compound, which is a temperature-sensitive substance, is powdered and a filler made of irregular fine particles is added to improve the adhesion to the object to be coated.

  Example 1 of the temperature indicating paint according to claim 1 will be described. In Example 1, the temperature indicating paint is composed of a powder of a heat-fusible organic compound that melts at a preset arbitrary temperature, a filler made of amorphous fine particles, a polymer resin that performs a binding action, and a solvent. Yes.

  The heat-meltable organic compound that melts at a preset arbitrary temperature, which is one of the constituent elements of Example 1, is a liquid state that has been in a solid state until reaching a specific set temperature. These are organic compounds having the property of changing phase, such as petroleum wax, trilaurin, myristic acid, palmitic acid, behenic acid, stearic acid and other fatty acid compounds, stearic acid amide, methylol amide, zinc stearate and other fatty acid compounds, etc. Illustrated. These are known substances that have been conventionally used as seal-type sensing substances for temperature sensors. In Example 1, these substances are in the form of powder.

On the other hand, examples of the filler composed of irregular fine particles include irregular fine particles such as starch, silica, alumina, talc, sodium oxide, calcium carbonate, kaolin, aluminum silicate, and barium sulfate, or a mixture thereof. In this example, a mixture of 82 wt% SiO ₂ fine particles, 10 wt% Al ₂ O ₃ fine particles and 8 wt% Na ₂ O fine particles was used as the filler. This filler bears the effect | action which improves the adhesiveness to the to-be-coated target object of the said heat-meltable organic compound. Furthermore, examples of the polymer resin that performs the binding action include rubber resins, xylene resins, polyester resins, styrene resins, acrylic resins, polyamide resins, polyacetal resins, urethane resins, epoxy resins, and polyurethane resins. Examples of the solvent include water-soluble solvents such as water, aliphatic hydrocarbon solvents, alcohols, esters, ethers, ketones, aromatic hydrocarbon solvents, petroleum solvents, and the like. In Example 1, ethyl cellulose was used as the polymer resin and butanol was used as the solvent. The mixing ratio of these heat-fusible organic compound, filler, polymer resin, and solvent in Example 1 was 25% by weight for the heat-fusible organic compound, 5-20% by weight for the filler, and 2. 5 to 10 wt%, and the solvent was 50 to 70 wt%. However, the blending ratio naturally varies depending on the type and concentration of the heat-fusible organic compound, filler, polymer resin, and solvent, and is of course not limited to the blending ratio.

  The temperature indicating paint according to Example 1 is manufactured by the following process. That is, the heat-fusible organic compound that melts at an arbitrary temperature in a solid state, the filler, the polymer resin, and the solvent are prepared so as to have the above mixing ratio, and are put into a ball mill. Kneaded and kneaded, the heat-fusible organic compound is pulverized into a powder, and a white, opaque fluid that is uniformly mixed with the filler, polymer resin and solvent is taken out of the ball mill and used as a temperature indicating paint. .

  The aforementioned heat-fusible organic compound originally has a transparent or translucent property, but the aggregate of powder-like heat-fusible organic compound pulverized into powder by a ball mill does not transmit light. Since it is irregularly reflected, it has an opaque and white tone. The polymer resin serves as a binder that binds the particles of the powdered heat-fusible organic compound to each other, the solvent serves to impart fluidity to the temperature-indicating paint, and the filler serves as the temperature-indicating paint. It fulfills the function of adhering to an object to be coated stably and firmly.

  As described above, this temperature indicating paint has a white and opaque fluid state, and is used for temperature indicating by being treated as follows. That is, as shown in FIG. 2, it is applied to the chromatic surface 4 of the colored paper 3 and allowed to stand for a certain period of time to evaporate the solvent, thereby forming a white temperature-sensitive layer 5 on the colored paper 3. If the colored paper 3 on which the temperature sensitive layer 5 is formed is placed on the substrate 1 so that the temperature sensitive layer 5 is on the upper side and the entire upper surface is covered with the transparent film 6, a seal-like temperature sensing element is obtained. . In the figure, 9 is an adhesive layer.

  The temperature sensor made in this way is affixed to a desired part of the device whose temperature is to be measured in the same manner as a conventional seal-like temperature sensor, and is used. And when the pasting part of this equipment exceeds a preset temperature, the powdery heat-fusible organic compound constituting the temperature-sensitive layer 5 is melted and gathered together to become a liquid, Due to the phase change, the temperature-sensitive layer 5 which has been white until then changes to transparent, and the colored surface 4 of the colored paper 3 can be seen through.

  Accordingly, the display portion of the temperature sensing body, which has been white until now, appears to be colored and displays the fact that the set temperature has been exceeded. In addition, when temperature falls once after exceeding preset temperature, the phase of the heat-meltable organic compound forming the temperature-sensitive layer 7 changes again from liquid to solid, but it does not return to powder. Because there is no, there is no change in the transparent state even if solidified.

  FIG. 3 shows another method of using this temperature indicating paint. Depending on the material of the device whose temperature is to be measured, the surface of the device is used without using colored paper 3 as shown in FIG. This temperature indicating paint can be directly applied to make an irreversible temperature sensor.

  That is, a color, a symbol, a number, or a figure is previously entered in a predetermined portion 7 of the temperature measurement object 8, and the temperature-sensitive layer 5 is formed thereon by applying the temperature indicating paint, and its upper surface is transparent. When covered with the film 6, the temperature sensing body is completed. In this case as well, the color, symbol, number, figure, or the like written in the predetermined portion 7 is changed when the temperature sensitive layer 5 changes from opaque to transparent when the set temperature is exceeded, as in the case described above. Will show through, and this will indicate the fact that the set temperature has been exceeded.

  As described above, the temperature indicating paint according to the present invention does not require any absorption paper and can be directly applied to colored paper or a temperature measurement object. It can be easily manufactured at low cost. In addition, since it is not necessary to use absorbent paper, the thermal conductivity is good and the temperature sensing accuracy can be improved. Furthermore, the seal-like temperature sensor can be made thinner, and can be installed even in a small gap that cannot be installed in the conventional one. In addition, since it can be applied directly to colored paper or a temperature measurement object, there is no risk of wrong combination of absorbent paper and colored paper in the manufacturing process, and there is no risk of defective products. As described above, the temperature indicating paint and the temperature sensor using the temperature indicating paint have excellent characteristics which are not found in the prior art, and have extremely high practical value.

  It can be used in all fields that require temperature control, including the power industry, food manufacturing industry, and semiconductor manufacturing industry.

The expanded sectional view of the typical example of the seal-like temperature sensing body which used the conventional wax as a melting material. The expansion perspective view of one Example of the seal-shaped temperature sensing body manufactured using the temperature indicating paint of Claim 1. Similarly, the expanded sectional view of another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Absorbing paper 3 Colored paper 4 Colored surface 5 Temperature sensitive layer 6 Transparent film 7 Predetermined part 8 Temperature measuring object 9 Adhesive layer

Claims (3)

A temperature indication characterized in that a solvent is mixed with a heat-fusible organic compound powder that melts at an arbitrary preset temperature, a filler made of amorphous fine particles, and a polymer resin that has a binding action. paint. A temperature-sensitive layer 5 coated with a temperature indicating paint mixed with a powder of a heat-fusible organic compound that melts at an arbitrary preset temperature, a filler made of irregular fine particles, and a polymer resin that performs a binding action, A seal-like temperature sensor formed on the chromatic surface 4 of the colored paper 3. A temperature-sensitive layer 5 coated with a temperature indicating paint mixed with a powder of a heat-fusible organic compound that melts at an arbitrary preset temperature, a filler made of irregular fine particles, and a polymer resin that performs a binding action, A temperature sensing body characterized in that it is formed directly on a predetermined part 7 of the temperature measurement object 8 to be measured.

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