JP2668635B2 - Reversible temperature indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reversible thermometer which can record and store a heat history and can be used repeatedly.

[0002]

2. Description of the Related Art Alcohol thermometers, mercury thermometers, thermistor thermometers and the like are routinely used to measure temperature, and these are widely used in the industrial field. In addition to these, as a means for easily measuring and displaying the temperature, temperature-sensitive ink, temperature-sensitive paint, etc. can be exemplified. The latter is mainly composed of a substance having a property of discoloring by heat and a binder, and can be used by a method such as directly applying it to a measurement site or attaching an applied substance on a support.
Therefore, it can be transformed into a desired shape,
Places that cannot be measured with general thermometers, such as flat surfaces,
The temperature distribution on the side surface of the three-dimensional object can be measured. These are widely used under the names such as thermo labels, and are collectively called temperature indicating materials. As the temperature indicating material, there are a reversible type in which the color returns when the temperature returns to the original, and an irreversible type in which the color does not return even when the temperature returns to the original.

[0003] A reversible thermometer generally uses a microencapsulated liquid crystal material. Like an alcohol thermometer or a mercury thermometer, the temperature at that time can be measured, but it can be recorded. It is not suitable for managing heat history, etc. The irreversible type utilizes a melting reaction of a fat or oil such as a fusible pigment or wax. If the device is used in a place where it cannot be constantly monitored by temperature control, a record such as a heat history of the measured portion remains, which is convenient.
However, it has a drawback that it cannot be reused once it has been heated and used.

[0004]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 55-1541
No. 78 and Japanese Unexamined Patent Publication No. Sho 62-257883 disclose a reversible thermosensitive recording material that makes an image reversibly opaque and transparent by heat, that is, a reversible thermosensitive recording material that is irreversible but can be reused. It has been disclosed.

However, the conventional reversible thermosensitive recording material disclosed in the above specification has a narrow transparentization temperature range, that is, a narrow temperature range for changing from a transparent state to a cloudy state or from a cloudy state to a transparent state. The measurable temperature was limited. For this reason, the conventional reversible thermosensitive recording materials are used only in a limited number of situations and cannot be used over a wide range.

Accordingly, it is an object of the present invention to provide a novel temperature indicator which can solve the above-mentioned drawbacks of the temperature indicator such as a thermo label, has a wide temperature range for clearing, and can be used over a wide range. Is what you do.

[0007]

SUMMARY OF THE INVENTION The present invention provides a method for manufacturing a semiconductor device comprising the steps of:
A reversible temperature indicator provided with a temperature indicator layer formed by dispersing an organic low-molecular substance into fine particles in an organic polymer resin, wherein the organic low-molecular substance is a long-chain alkyl group having a melting point of 50 ° C to 100 ° C. At least one kind of compound and a melting point of 100 to 1
At least one of the alkyl group-containing compounds at 60 ° C.
The above object was achieved by using a substance mixed at a ratio of 8: 2 to 50:50.

In the present specification, a layer constituting a reversible thermometer, which has a function of being able to be in a transparent state or a cloudy state due to a temperature change or a heat history, is hereinafter referred to as a thermometer. This temperature indicator layer is composed of an organic polymer resin and an organic low-molecular substance, and the organic low-molecular substance is dispersed in fine particles in the organic polymer resin. The reversible temperature indicator of the present invention,
It has a function of taking a cloudy state or a transparent state after cooling due to a difference in heating temperature and stably maintaining that state. Moreover, the transparency change of this temperature indicator is not irreversible, and it has a great feature that it can be reused many times even if it has been discolored by heating once. Further, the reversible temperature indicator of the present invention can be conveniently divided into a high temperature heating type and a low temperature heating type depending on the temperature at which it becomes cloudy.
The high temperature heating type reversible temperature indicator is a type in which the heating temperature at which the reversible temperature indicator becomes cloudy after being cooled is higher than the temperature at which it becomes transparent. The low-temperature heating type reversible temperature indicator is a type in which the heating temperature for making it cloudy is lower than the heating temperature for making it transparent. Both types of reversible temperature indicator are essentially the same and can be treated similarly.

The relationship between the optical state of the reversible thermometer of the present invention having the above-mentioned characteristics and the thermal history applied thereto will be described with reference to FIG. FIG. 1 schematically shows the relationship between the heating temperature of the high-temperature heating type reversible thermometer and the optical state of the reversible thermometer at that temperature on the horizontal axis. (The reversible temperature indicator of low temperature heating type is shown in FIG. 2.)

First, the case where the reversible temperature indicator in a cloudy state at room temperature becomes transparent will be described. When the reversible thermochromic material in the cloudy state is heated (), the material gradually starts to become transparent (), and reaches a certain temperature range T _{1 to} T ₂ (this temperature range is referred to as T _W, and is hereinafter abbreviated to the transparent temperature range). When it reaches, it becomes almost transparent. From this state, when gradually cooled to room temperature T _R , it becomes completely transparent and becomes the maximum transparent state.
Is kept stable at room temperature (in FIG. 1, the thermal history can be expressed as →→→. In FIG. 2, A → B).
→ C → D ).

The case where the reversible temperature indicator in the transparent state is clouded will be described. The reversible temperature indicating material is heated from a transparent state, and becomes a translucent state when the temperature reaches or exceeds a temperature T ₃ (hereinafter, referred to as a clouding temperature). When cooling is started from this state, the semitransparent state is maintained for a while, but it begins to turn cloudy at a certain temperature, and when it is cooled to room temperature T _R, it becomes completely clouded. This white turbid state is kept stable at room temperature (the heat history is represented as →→→→ in FIG. 1; in FIG. 2, it is represented as D → B → A).

As described above, the optical state of the reversible temperature indicator of the present invention at room temperature may be arbitrarily selected between a transparent state and a cloudy state depending on how many times the reversible temperature indicator is heated. That you can do it. That is, the optical state can be arbitrarily selected by heating to the transparent temperature range or to the clouding temperature.

[0013] a transparentization temperature range of 80 ° C to 110 ° C;
The case where a reversible temperature indicator having an opacity temperature of 110 ° C. or higher is heated to be in a transparent state, attached to a portion to be measured such as a heat generating portion of a transformer, and the transformer is energized will be described below. When a transformer is energized, it loses heat due to its power loss, and the temperature of the transformer rises to a certain point. When the reversible temperature indicator is in a transparent state after the power is terminated and the transformer is sufficiently cooled, the transformer has a transparent temperature range, that is, 80
It turns out that it heated to 110-110 degreeC. In the case of a cloudy state, it can be seen that the film was heated to a clouding temperature, that is, 110 ° C. or higher.

As the organic polymer resin used for the temperature indicator of the present invention, those having good transparency, excellent mechanical strength, and good film-forming properties are preferable. In addition, by selecting this organic polymer resin, for example, when using a thermoplastic resin such as vinyl chloride-vinyl acetate copolymer, the characteristics of the high-temperature heating type can be obtained, such as a styrene-butadiene copolymer. When a thermoplastic elastomer is used, the above low temperature heating type characteristics can be obtained. Specific examples of the organic polymer resin include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-vinyl alcohol copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, vinyl chloride- Vinyl acetate-phosphate ester copolymer, vinyl chloride-acrylate copolymer, polyvinylidene chloride,
Vinylidene chloride-vinyl chloride copolymer, vinylidene chloride-acrylonitrile copolymer, polyester resin, polyamide resin, acrylic resin, silicone resin, styrene butadiene copolymer, trans polyisoprene, amorphous ethylene-propylene, polyvinyl butyral, etc. preferable.

The low-molecular organic substance contained in the temperature indicator of the present invention includes a long-chain alkyl group-containing compound having a melting point of 50 ° C. or more and less than 100 ° C. (hereinafter referred to as a low-melting organic low-molecular substance) and a melting point of 100 ° C. above 160 alkyl group-containing compound ℃ or less (hereinafter referred to as high melting point organic low molecular weight substance)
Is used. The low-melting organic low-molecular substance is selected from the fatty acids, alcohols, esters, amides, ketone compounds, etc., containing a long-chain alkyl group having 14 to 50 carbon atoms, depending on the melting point. Specifically, palmitic acid, stearic acid,
Fatty acids such as behenic acid and montanic acid, stearyl alcohol, behenyl alcohol, alcohols such as C30 alcohol and C50 alcohol, stearyl stearate, behenyl stearate, behenyl behenate, behenyl montanate, C30 alcohol stearate, C30 alcohol behenate, stearin Acid C50 alcohol, behenic acid C50 alcohol ester, ester of eicosadic acid stearyl alcohol diester, etc., palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, N-stearyl stearic acid amide, N
Examples include, but are not limited to, amides such as oleyl palmitate amide, N-stearyl erucate amide and N-stearyl oleate amide, and ketones such as distearyl ketone and dibehenyl ketone. Further, these low-melting point organic low-molecular substances may be used alone, or two or more kinds may be used.

On the other hand, examples of the high-melting-point organic low-molecular substance include saturated fatty acid bisamide, saturated aliphatic dicarboxylic acid, saturated fatty acid monoamides such as stearic acid amide and behenic acid amide, methylol amides such as methylol stearic acid amide, and hexamethylene. Bisoleic acid amide,
Unsaturated fatty acid bisamides such as N, N'-dioleyladipamide, aromatic bisamides such as m-xylylenebisstearic acid amide, N-stearyl-N'-
Melting point of 100 ℃ from substituted ureas such as stearyl urea
What is in the range of -160 ° C can be used. this house,
Saturated aliphatic bisamides and saturated aliphatic dicarboxylic acids are preferred.

The saturated aliphatic bisamide means an acid amide of a long chain saturated aliphatic and an alkylenediamine or an acid amide of a saturated aliphatic dicarboxylic acid and a long saturated aliphatic amine. Specifically, the following are mentioned. Ethylenebisstearic acid amide Melting point 143 ° C. (C ₁₇ H ₃₅ CONH) ₂ (CH ₂ ) ₂ Ethylenebisbehenic acid amide Melting point 141 ° C. (C ₂₁ H ₄₃ CONH) ₂ (CH ₂ ) ₂ Hexamethylene bisstearic acid amide Melting point 146 _{℃ (C 17 H 35 CONH)} 2 (CH 2) 6 -hexamethylene bis behenic acid amide mp _{143 ℃ (C 21 H 43 CONH} ) 2 (CH 2) 6 N, N'- distearyl adipic acid amide mp 144 ° C. ( _{C 18 H 37 NHCO) 2 (} CH 2) 4 N, N'- distearyl Eiko Sanji acid amide mp _{128 ℃ (C 18 H 37 NHCO} ) 2 (CH 2) 18 N, N'- distearyl sebacic acid amide mp 138 ° C. (C ₁₈ H ₃₇ NHCO) ₂ (CH ₂ ) ₈ N, N′-dilauryldecanedioic acid amide Melting point 138 ° C. (C ₁₂ H ₂₅ NHCO) ₂ (CH ₂ ) ₁₀ N, N′-dilauryl eicosane diacid amide melting point 130 ° C. (C ₁₂ H ₂₅ NHCO) ₂ (CH ₂ ) ₁₈ N, N′-distearyl dodecanedioic acid amide melting point 130 ° C. (C ₁₈ H ₃₇ NHCO) ) ₂ (CH ₂ ) _{10 and} dicarboxylic acids include the following. Adipic acid HOOC (CH ₂ ) ₄ COOH melting point 153 ° C. pimelic acid HOOC (CH ₂ ) ₅ COOH melting point 105 ° C. suberic acid HOOC (CH ₂ ) ₆ COOH melting point 140 ° azelaic acid HOOC (CH ₂ ) ₇ COOH melting point 107 ° C. sebacic acid HOOC (CH ₂ ) ₈ COOH melting point 133 ° C. undecandioic acid HOOC (CH ₂ ) ₉ COOH melting point 111 ° C. dodecandioic acid HOOC (CH ₂ ) ₁₀ COOH melting point 128 ° C. tridecandioic acid HOOC (CH ₂ ) ₁₁ COOH melting point 113 ° C. tetradecanoic acid HO (CH _{2) 12} COOH mp 125 ° C. Pentadekanji acid HOOC (CH _{2) 13} COOH mp 115 ° C. Hekisadekanji acid HOOC (CH _{2) 14} COOH mp 125 ° C. Heputadekanji acid HOOC (CH _{2) 15} COOH mp 1 8 ° C. Okutadekanji acid HOOC (CH _{2) 16} COOH mp 125 ° C. Nonadekanji acid HOOC (CH _{2) 17} COOH mp 119 ° C. Eikosanji acid HOOC (CH _{2) 18} COOH mp 120 ° C. It should be noted that the high melting point organic low molecular substances which are, One type may be used, or two or more types may be used.

When a high-melting point organic low-molecular substance is added to the above-mentioned low-melting point organic low-molecular substance, the upper limit T2 of the clearing temperature range Tw can be shifted to a higher temperature side. As a result, the clearing temperature range Tw becomes wider. . Further, by adjusting the addition amount of the high melting point organic low molecular weight substance, the clouding temperature or the clearing temperature range can be freely controlled. In general,
When a mixture of a low melting point organic low molecular weight substance and a high melting point organic low molecular weight substance is used as the organic low molecular weight substance, the lower limit of the transparency temperature range Tw is several degrees Celsius above the melting point of the low melting point organic low molecular weight substance.
Lower. That is, by appropriately selecting the low-melting point organic low-molecular substance and the high-melting point organic low-molecular substance, the transparentizing temperature range and the transparentizing temperature range can be controlled.

In the present invention, the blending ratio of the low-melting point organic low-molecular substance and the high-melting point organic low-molecular substance is 9% by weight.
It is preferably in the range of 8: 2 to 50:50. If the ratio of the high melting point organic low molecular weight substance to the whole organic low molecular weight substance is 2% by weight or less, no effect can be obtained against the expansion of the transparentization temperature range, while if it is higher than 50% by weight, the degree of white turbidity Is not preferable because it deteriorates.

The compounding amount of the organic low molecular weight substance to be dispersed in the organic high molecular weight resin is 5 parts by weight including the low melting point organic low molecular weight substance and the high melting point organic low molecular weight substance based on 100 parts by weight of the organic high molecular weight resin. It is preferably in the range of 100 parts by weight to 100 parts by weight, and particularly preferably in the range of 10 parts by weight to 50 parts by weight. When the amount of the organic low-molecular substance is less than 5 parts by weight, the reversible temperature indicator is not sufficiently opaque and good contrast cannot be obtained. Conversely, when the amount is more than 100 parts by weight, the reversible temperature indicator is formed. This is not preferred because the properties deteriorate.

Further, additives such as a plasticizer and a surfactant can be added to the temperature indicating layer of the present reversible temperature indicating material, if necessary. By adding these, there is an effect of improving the transparency of the reversible temperature indicator in the transparent state and widening the temperature range for the transparency. For example, plasticizers include tributyl phosphate, tri-2-ethylexyl phosphate, triphenyl phosphate, tricresyl phosphate, butyl oleate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, diphthalate. -N-octyl, di-2-ethylhexyl phthalate, diisononyl phthalate, dioctyldecyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, dibutyl adipate,
Di-n-hexyl adipate, di-2-ethylhexyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, di-2-ethylhexyl sebacate, diethylene glycol dibenzoate, triethylene glycol di-2-ethyl butyrate Etc. can be exemplified. Further, as the surfactant, polyhydric alcohol higher fatty acid ester, polyhydric alcohol higher alkyl ether, higher alcohol, higher alkylphenol, higher fatty acid higher alkylamine, higher fatty acid amide, higher alkylbenzenesulfonic acid Na, Ca, Ba or Mg salt Etc. can be exemplified. However, the above substances are merely examples, and the present invention is not limited thereto.

As the support used in the reversible temperature indicator of the present invention, synthetic resin films such as polyvinyl chloride, polyester, polycarbonate, etc., paper, metal foil, metal plate, glass and the like can be used. Further, a colored layer may be provided on the front surface or the rear surface, or a synthetic resin film in which a colored pigment is kneaded may be used. Furthermore, it is also possible to attach a metal foil as a light reflection layer on the front surface or the back surface, or to provide a metal deposition layer. In addition, as long as the temperature indicating layer has sufficient mechanical strength to maintain its shape, it can be used alone without using a support.

The method for producing the reversible temperature indicator of the present invention will be described below. First, a method for manufacturing the temperature indicating layer will be described. The temperature indicating layer of the reversible temperature indicating material in the present invention, an organic polymer resin, a low-melting organic low-molecular substance, and a high-melting organic low-molecular substance dissolved in a solvent, or a coating liquid obtained by dispersing the coating liquid on a support. It can be provided by coating, printing, or forming a film by another method. When a temperature indicating layer is formed by applying the above solution, the thickness of the temperature indicating layer is preferably 1 μm or more, and more preferably in the range of 3 to 60 μm. When the thickness is less than 1 μm, the turbidity of the temperature indicating layer is not sufficient, and when it is more than 60 μm, the transparency is deteriorated, which is not preferable.

In the formed temperature indicator, the organic low-molecular substance is present in a state of being dispersed in the polymer resin in the form of particles. The particle size of the organic low-molecular substance is about 0.5 to 2
It is distributed in the range of μm.

[0025] The reversible temperature indicator of the present invention can be used, if necessary,
For example, a layer configuration described below can be employed. 3 to 10 schematically show these. However, it is needless to say that the layer structure can take various forms depending on the purpose of use, the situation of use, the place of use, etc., and the following examples are not all. FIG.
It is a figure which shows the example which has a two-layer structure which provided the temperature indicating layer on the support body. In this case, the temperature indicating layer may be coated on the support,
It can be created by transferring or pasting. Further, it is also possible to apply it on the surface of a support having releasability, then peel it off, and use it only as a temperature indicator layer.

FIGS. 4 and 5 are diagrams showing a temperature indicating material when several kinds of temperature indicating layers having different clearing temperature widths and white turbidity temperatures are provided on the same support. Can be. FIG. 4 shows a structure in which the temperature indicating layers are laminated. Since the turbidity temperature of each layer is different, if the temperature of the non-measurement portion is high, the number of opaque layers increases, and the turbidity increases. When the temperature is low, the white turbidity decreases because there are few layers that become cloudy, and therefore the white turbidity changes stepwise within a certain temperature range. Therefore, it is convenient because the temperature distribution becomes light and shade and can be visualized. Further, FIG. 5 shows that the temperature indicating layers are arranged at different positions on the support, and the attainable temperature of the temperature indicating material can be known from which temperature indicating layer becomes transparent or cloudy. is there.

FIG. 6 is a schematic diagram showing a temperature indicator provided with a metal layer as a reflective layer for improving the contrast between the transparent state and the cloudy state. This metal layer can be provided as a metal foil or a vapor deposition film, and is made of Al, Zn, Sn, A
g, Au and the like are preferable.

FIG. 7 is a schematic diagram showing the temperature indicating material when characters such as temperature are printed. When the temperature indicating material is heated to the transparent temperature range, the temperature indicating layer becomes transparent after heating and cooling so that the character can be seen, which is more convenient. Further, when heated to a temperature higher than the clouding temperature, the temperature indicating layer becomes cloudy, so that the contrast between the character and the background disappears and the character disappears apparently. That is, the printed characters are hidden by the temperature indicating layer. In the temperature indicator shown in FIG. 7, the temperature indicator layer is provided on the metal vapor deposition layer and white characters are printed on the temperature indicator layer, but the characters may be provided below the temperature indicator layer. Further, the color of the character need not be white.

FIG. 8 is a schematic view showing a temperature indicating material provided with a protective layer. This protective layer is a layer laminated on the surface of the temperature indicating layer to protect the temperature indicating layer, such as a silicone resin, an acrylic resin, an alkyd resin, or a photo-curable or electron beam-curable urethane-acrylate resin. A resin having high heat resistance can be provided as a main component. In addition to the above components, an additive such as silicone may be added for the purpose of improving the surface property of the temperature indicating material, for example, water repellency.

FIG. 9 is a schematic view showing a temperature indicating material having an intermediate layer provided between the temperature indicating layer and the protective layer. This intermediate layer is formed by preventing the organic low molecular weight substance in the temperature indicating layer from migrating to another layer, by increasing the adhesiveness between the temperature indicating layer and the protective layer, or by increasing the thickness on the temperature indicating layer. It is provided for the purpose of reducing thermal or mechanical damage to the temperature indicating layer.

FIG. 10 is a schematic view showing a case where an adhesive layer or a magnet is used to fix a reversible temperature indicator to a portion to be measured. The adhesive layer or the magnet is usually provided on the support side of the support / thermothermic layer, but when the support is transparent,
An adhesive or a magnet may be provided on the temperature indicating layer.

[0032]

EXAMPLES The reversible temperature indicator of the present invention will be described in more detail with reference to the following examples. In the examples, "part" means "part by weight".

Example 1 A transparent polyethylene terephthalate film having a thickness of 50 μm was coated on one side with aluminum as a support, and a coating for a temperature indicator having the following composition was coated on the opposite side of the aluminum-deposited surface of the support. The side was coated using a wire bar. After drying, a thermochromic layer having a thickness of 10 μm was formed. Behenyl montanate (melting point: 80 ° C.) 95 parts N, N′-distearyldodecanedioic acid amide (melting point: 130 ° C.) 5 parts Vinyl chloride-vinyl acetate copolymer 300 parts Tetrahydrofuran 1600 parts The above behenyl montanate is As the low melting point organic low molecular weight substance, N, N'-distearyldodecanedioic acid amide was contained as the high melting point organic low molecular weight substance.

After forming the reversible temperature indicator of the present embodiment in this manner, a heat block heated to a predetermined temperature using a thermal gradient tester at a pressure of 400 g / m ² for 1 second.
The sample was pressed against the obtained sample of the reversible temperature indicating medium, and the temperature at which the temperature indicating layer became transparent and clouded was measured. Specifically, the part where the heat block was pressed became transparent,
The temperature range in which the aluminum vapor deposition surface under the temperature indicating layer gives off a metallic luster was measured as the clearing temperature range.

(Example 2) In Example 1, 5 parts of N, N'-distearyldodecanediamide was contained in the thermochromic coating, whereas Example 1 was changed except that 4 parts were contained. A temperature indicating layer was formed by the same method to obtain a reversible temperature indicating material, and its transparent temperature range was measured.

(Example 3) In Example 1, 5 parts of N, N'-distearyldodecandioic acid amide was contained in the thermochromic coating, whereas Example 1 was repeated except that 3 parts were contained. A temperature indicating layer was formed by the same method to obtain a reversible temperature indicating material, and its transparent temperature range was measured.

Example 4 In Example 1, 5 parts of N, N'-distearyldodecandioic acid amide was contained in the thermostatic layer coating material, whereas Example 1 was repeated except that 2 parts were contained. A temperature-indicating layer was formed by the same method to obtain a reversible temperature-indicating material, and the temperature range for the transparency was measured.

(Comparative Example 1) In Example 1, 5 parts of N, N'-distearyldodecanediamide was contained in the thermochromic coating composition, whereas Example 1 was changed except that 1 part was contained. A temperature indicating layer was formed by the same method to obtain a reversible temperature indicating material, and its transparent temperature range was measured.

(Comparative Example 2) In Example 1, 5 parts of N, N'-distearyldodecandioic acid amide was contained in the thermostatic layer paint, but in contrast to Example 1, except that 60 parts of N, N'-distearyl dodecanediamide was contained. A temperature-indicating layer was formed by the same method to obtain a reversible temperature-indicating material, and the temperature range for the transparency was measured.

Example 5 The same operation as in Example 1 was carried out except that the coating composition in Example was changed to the following. Stearic acid (melting point: 65 ° C.) 75 parts Suberic acid (melting point: 140 ° C.) 25 parts Vinyl chloride-vinyl acetate copolymer 350 parts Tetrahydrofuran 1800 parts The above-mentioned stearic acid is a low-melting organic low-molecular substance, and suberic acid is It was contained as a high melting point organic low molecular weight substance.

Comparative Example 3 In Example 1, N, N'-distearyldodecanediamide (melting point: 1)
(30 ° C.), and 5 parts of N-stearylstearic acid amide (melting point: 94 ° C.) except that 5 parts of N-stearylstearic acid amide was contained to form a thermochromic layer in the same manner as in Example 1 to form a reversible layer. A temperature indicating material was obtained, and the transparency temperature range was measured.

(Comparative Example 4) In Example 1, N, N'-distearyldodecanediamide (melting point: 8)
0 ° C.), and 5 parts of hexamethylene bisstearyl urea (melting point: 173 ° C.) except that 5 parts of hexamethylene bisstearyl urea (melting point: 173 ° C.) was used. Was obtained, and the clarification temperature range was measured.

Comparative Example 5 In Example 1, 95 parts of behenyl montanate (melting point: 80 ° C.) was contained in the thermochromic coating, whereas N-oleyl oleic acid amide (melting point: 45 ° C.) was added. A temperature indicator layer was formed in the same manner as in Example 1 except that 95 parts were contained, a reversible temperature indicator was obtained, and the transparency temperature range was measured.

(Comparative Example 6) In Example 1, 95 parts of behenyl montanate (melting point: 80 ° C.) was contained in the thermostatic layer paint, whereas amide stearic acid (melting point: 107 ° C.) was used.
(C) was included in the same manner as in Example 1 except that the reversible temperature indicating material was obtained, and the transparent temperature range was measured.

Table 1 shows the results of measuring the transparent temperature range and the clouding temperature.

According to the measurement results shown in Table 1, the transparency temperature range and the clouding temperature can be easily adjusted by adjusting the amount of N, N'-distearyldodecanediamide, which is a high-melting organic low-molecular substance. You can see that it can be changed. Thereby, temperature indicating materials having different characteristics can be created. In particular, as can be seen by comparing Examples 1 to 5 with Comparative Examples 1 and 2, the reversible temperature indicating material of this example was based on N, N'-distearyl with 95 parts of behenyl montanate. Since both are contained so that the content of dodecanediamide becomes 2 to 50 parts, the reversible temperature indicator of the present example can take a transparent state and a cloudy state, and the reversible temperature indicator of the comparative example. The transparency temperature range is wider than that of the temperature indicator.

Further, Examples 1 to 5 are compared with Comparative Examples 3 to 6. The reversible temperature indicator of the comparative example is an organic low molecular weight substance, and the low melting point organic low molecular weight substance is 50 ° C.
High melting point organic low molecular weight material is 100 ℃
Each of the temperature-indicating materials was selected to have no melting point in the range of up to 160 ° C., but both had extremely narrow transparent temperature ranges or did not become cloudy. On the other hand, the reversible temperature indicator of the present example, behenyl montanate having a melting point within the above range,
Since it is used as an organic low molecular weight substance by containing N, N'-distearyldodecanedioic acid amide, it has a transparent temperature range and is wide.

Further, comparing the measurement results of Example 1 and Example 5, the low-melting point organic low-molecular substance was converted from behenyl montanate (melting point: 80 ° C.) to stearic acid (melting point: 65 ° C.).
It can be seen that the lower limit of the transparentization temperature range is lowered by 15 ° C. only by changing to, and the lower limit value of the transparentization temperature range greatly depends on the low melting point organic low molecular weight substance.

Next, the durability of the obtained reversible temperature indicator was examined by repeating 50 cycles of "heating to the transparent temperature range → cooling → heating to the clouding temperature → cooling" as one cycle. As a result, there was no change in the clearing temperature range and the white turbidity temperature of the reversible temperature indicator of this example, and the transparent state and the white turbid state were visually confirmed. Turned out to be high.

Further, in order to examine the storage stability at room temperature, the state immediately after heating and cooling and the state after storage for 48 hours were visually checked, and it was examined whether or not a record of heat history was left. It was found that the reversible temperature indicator of No. 2 had a very good preservability even if it was stored for a long time without showing any difference in the recording state before and after the storage.

Next, reversible thermoelectric materials having various layer structures will be described based on Examples. (Example 6) A transparent polyethylene terephthalate film having a thickness of 50 µm was used as a support, and then a metal layer was formed on the support by aluminum vapor deposition, and the temperature indicating layer used in Examples 1 to 4 was formed thereon. Each of the paints for application was applied such that the thickness of the temperature indicating layer after drying was 10 μm, and a reversible temperature indicating material of the present example in which temperature indicating layers having different clearing temperature widths and white turbidity temperatures were laminated was prepared. Then, using a thermal gradient tester, the reversible temperature indicator obtained was heated at various heating temperatures, and the white turbidity after heating and cooling was examined. The white turbidity was measured with a Macbeth densitometer RD-914. Table 2 shows the results.

Example 7 A transparent polyethylene terephthalate film having a thickness of 50 μm was used as a support, aluminum was deposited to form a metal layer, and the coating for the temperature indicating layer used in Example 3 was dried. The reversible temperature-indicating material of this example was prepared by coating so as to have a thickness of 40 μm.
The whiteness of this reversible temperature indicator was measured in the same manner as in Example 6. Table 2 shows the results.

Hereinafter, margins. The numerical values in Table 2 showing the optical state of the reversible temperature-indicating material after cooling indicate that the larger the value, the more transparent, and the smaller the value, the whiter.

As can be seen from Table 2, the reversible thermometers of Examples 6 and 7 are formed by stacking temperature indicating layers having different clearing temperature ranges and different whitening temperature ranges. The whiteness within a certain temperature range can be changed instead of changing only one specific temperature.

Example 8 A transparent polyethylene terephthalate film having a thickness of 50 μm was used as a support, an aluminum metal layer was provided thereon, and the coating for the temperature indicating layer used in Example 1 was dried. Is applied so that the thickness of the temperature indicator layer becomes 10 μm, and the temperature indicator layer (clearing temperature range: 7)
7.5 ° C. to 115.0 ° C., white turbidity temperature: 115.0 ° C. or higher) were obtained. Further, aluminum was vapor-deposited in a character shape of "Tomogawa" on the reversible temperature indicating material of the present example. The obtained reversible temperature indicator was heated in an oven at 90 ° C. and then cooled, and compared with a state in which it was heated in an oven at 120 ° C. and then cooled.

Example 9 A transparent polyethylene terephthalate film having a thickness of 50 μm was used as a support, aluminum was deposited thereon to form a metal layer, and white paper “paper mill” was printed thereon. Further, the temperature-indicating layer having a thickness of 10 after drying the temperature-indicating layer paint used in Example 1 thereon.
μm and a temperature indicating layer (clearing temperature range: 7
7.5 ° C. to 115.0 ° C., turbidity temperature: 115.0 ° C. or higher) to prepare the reversible temperature indicator of this example. In the same manner as in Example 8, the obtained reversible temperature indicator was heated in an oven at 90 ° C. and then cooled, and was then heated in an oven at 120 ° C. and then cooled.

In Example 8, what was heated to 90 ° C. became transparent and became aluminum ground, and the characters “Hawakawa” written by aluminum vapor deposition became invisible. On the other hand, when heated to 120 ° C., the thermochromic layer became cloudy, and the letters “Tomogawa” clearly appeared on a white background. The visibility of the letters was very good. Example 9 is different from Example 8 in that characters are obtained by making it transparent, and when heated to 90 ° C., the letters “Paper Mill” can be confirmed, but those heated to 120 ° C. Could not confirm the characters were hidden. From these experimental results, it was found that the printed characters can be clearly recognized in the reversible temperature indicating material of the present example on which the characters are printed.

[0058]

The reversible temperature indicator of the present invention comprises a support,
A reversible temperature indicator having a temperature indicating layer formed by finely dispersing an organic low molecular weight substance in an organic polymer resin, wherein the organic low molecular weight substance has a long-chain alkyl having a melting point of 50 ° C to 100 ° C. At least one of the group-containing compounds and a melting point of 100
It is a reversible temperature indicator characterized in that it is a substance in which at least one of the alkyl group-containing compounds at a temperature of from 0 ° C to 160 ° C is mixed at a ratio of 98: 2 to 50:50, so that the transparentizing temperature range can be easily increased. Can be controlled. Therefore, the reversible temperature indicator of the present invention acts on a desired temperature depending on the use condition, and it can be recorded and indicated.
The use situation is not limited, and it can be used over a wide range.

[Brief description of the drawings]

FIG. 1 is a state diagram showing the relationship between heating temperature and transparency for a high temperature heating type reversible temperature indicator.

FIG. 2 is a state diagram showing a relationship between heating temperature and transparency for a low temperature heating type reversible temperature indicator.

FIG. 3 is a schematic sectional view showing a reversible temperature indicator having a support.

FIG. 4 is a schematic cross-sectional view showing a reversible temperature indicating material in which a plurality of temperature indicating layers having different clouding temperatures are laminated.

FIG. 5 is a schematic plan view showing a reversible thermometer in which a plurality of thermometers having different clouding temperatures are separately provided on the same support.

FIG. 6 is a schematic cross-sectional view showing a reversible temperature indicator having a metal layer.

FIG. 7 is a schematic cross-sectional view showing a reversible temperature indicating material on which characters are printed.

FIG. 8 is a schematic sectional view showing a reversible temperature indicator having a protective layer.

FIG. 9 is a schematic sectional view showing a reversible temperature indicator having an intermediate layer.

FIG. 10 is a schematic sectional view showing a reversible temperature indicator having an adhesive layer.

 ───────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Suzuki 3-1 Yosoba Tomoecho, Shizuoka City, Shizuoka Prefecture Inside the Information Media Division of Hamikawa Paper Mill Co., Ltd. (72) Inventor Kensaku Higashi Kensaku East No.3-1, Machi. In the Information Media Division of Hamakawa Paper Mill Co., Ltd. (56) References JP-A-62-257883 (JP, A)

Claims (3)

(57) [Claims] 1. A reversible temperature indicating material comprising a support and a temperature indicating layer comprising an organic high molecular weight resin in which fine particles of an organic low molecular weight are dispersed, wherein the organic low molecular weight substance has a melting point. and at least one long chain alkyl group-containing compound is less than 50 ° C. or higher 100 ° C. <br/>,
At least one and 98 of the melting point of the alkyl group-containing compound is less than 160 ° C. 100 ° C. or higher: 2 to 50: reversible temperature indicating material, which is a 50 material being mixed in a ratio of. 2. A according to claim 1, wherein the melting point <br/> Oh luer alkyl group-containing compound at 100 ° C. or higher 160 ° C. or less is at least saturated aliphatic bisamide or saturated aliphatic dicarboxylic acids Reversible thermometer. 3. A reversible temperature indicator having a plurality of temperature indicating layers according to claim 1 and claim 2, which have different transparentizing temperature regions or clouding temperatures.