JP2003004550A - Solid-form temperature display material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid-form temperature display material which allows easy checking of whether a predetermined temperature is achieved according to a clear change in color tone. SOLUTION: The solid-form temperature display material includes at least one kind of temperature-display material which changes its color by heat, and a paraffin wax and/or an inorganic binding material. The temperature-display material is selected from the group consisting of complex oxalate, metal oxalate, metal hydroxide, basic metal carbonate, metal phosphate, metal ammonium salt, complex ammonium, metal salt with an additive of hexamethylenetetramine, metal tetraiodo-mercurate, hydrate of these materials, and an organic pigment. The temperature-display material may also include at least one kind of material selected from the group consisting of solid-form fats, nonvolatile oils, and semi- solid-form fats. The solid-form fats include mineral wax, Japanese wax, beeswax, and/or animal fat. The nonvolatile oils include animal fat, vegetable oil, mineral oil, and/or liquid paraffin. The semi-solid-form fats include petrolatum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid temperature indicating material capable of easily confirming whether or not it has been overheated by a thermochromic pigment which is discolored by heat.

[0002]

2. Description of the Related Art A liquid temperature indicating material containing a thermochromic pigment which is discolored by heat is used for detecting overheating of a device such as a motor which should avoid overheating and for confirming temperature history.

Further, when the steel frame steel material and the weld metal are overheated during the multi-layer welding in which the steel frame steel material is welded with a number of weld metal layers, the welding strength is lowered. In order to avoid this, it is necessary to reduce the temperature in the vicinity of the welded portion immediately before the formation of a new weld metal layer, that is, the interpass temperature to a predetermined temperature or less before forming the next weld metal layer. At that time, a liquid temperature indicating material containing a temperature indicating pigment is used. While checking the degree of discoloration due to this display material, while providing an appropriate cooling time between passes to control the temperature between passes,
Welding is performed.

When the liquid temperature indicating material is applied to a test object such as a motor with a brush and then exposed to a predetermined temperature or higher, the pigment undergoes a structural change or a chemical change to cause a color change. This means that the changed color tone of the material will be visible. By using this, the temperature can be easily displayed with a clear change in color tone without using an expensive device such as a thermocouple.

However, the liquid temperature indicating material has a problem that if it drips during application, the object to be inspected and its surroundings will be soiled. Furthermore, when controlling the temperature between passes of steel welding,
It is troublesome that the brush has to be applied frequently each time a new portion is welded. Therefore, there has been a demand for a solid temperature indicating material that can be easily drawn.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and is a solid-state temperature display capable of easily confirming whether a predetermined temperature has been reached by a clear change in color tone. The purpose is to provide wood.

[0007]

The solid temperature indicating material of the present invention, which has been made to achieve the above-mentioned object, comprises at least one kind of thermochromic pigment which is discolored by heat, paraffin wax and / or binding property. And an inorganic compound of.

[0008] Paraffin wax and a binding inorganic compound are used to solidify the display material.
Since these do not burn when heated, the change in color tone due to the discoloration of the temperature-indicating pigment when the display material is exposed to a predetermined temperature is
It is clear.

The paraffin wax is preferably contained in an amount of 2 to 60% by weight. The display material containing the paraffin wax in this range has sufficient strength so that it is not easily broken during use or transportation, and the writing feeling when drawing on an object preheated above the melting point of the paraffin wax is particularly good. .

The melting point of the paraffin wax is preferably 50 ° C. or higher, and more preferably 55 to 70 ° C. in order to provide the temperature indicating material with sufficient storage stability and strength.

As the solid temperature indicating material, mineral wax,
At least one of solid fats and oils which are wood wax, beeswax and / or tallow, non-volatile oils which are animal oil, vegetable oil, mineral oil and / or liquid paraffin, and semi-solid fats and oils which are petrolatum are included. May be. Examples of solid fats and oils include ceresin wax, carnauba wax, old-fashioned seed wax, rice wax, and beef tallow. Examples of non-volatile oils include olive oil, machine oil, soybean oil, hydrocarbons and liquid paraffin.

The solid temperature indicating material has the effect of being able to draw easily regardless of the temperature and smoothness of the surface of the object to be inspected, and solid oil and fat and non-volatile oil and / or semi-solid oil and fat. When both and are included, this effect becomes more excellent.

The solid temperature indicating material is one of solid fats and oils.
It preferably contains 10% by weight, preferably 1 to 8% by weight. If the solid fat is less than 1% by weight, the display material can be drawn on an object preheated to a temperature above the melting point of paraffin wax, but it is difficult to draw on an object below the melting point. I will end up. Solid fats and oils burn if heated too much, and if it exceeds 10% by weight, the discoloration of the thermochromic pigment becomes unclear.

The solid temperature indicating material preferably contains 0.05 to 2% by weight, preferably 0.05 to 1% by weight, of the nonvolatile oil and / or the semisolid oil and fat. When the content is less than 0.05% by weight, the display material can be drawn on the test object preheated to the melting point of the paraffin wax or more, but it is difficult to draw on the test object below the melting point. . On the other hand, if it exceeds 2% by weight, oils and the like will ooze out, resulting in poor storage stability of the display material.

The thermochromic pigments include oxalic acid complex salts, oxalic acid metal salts, metal hydroxides, basic carbonic acid metal salts, phosphoric acid metal salts,
It is preferable to be selected from an addition product of hexamethylenetetramine to a metal salt, an ammonia complex salt, an ammonium metal salt, a tetraiodomercuric acid metal salt, a hydrate of these, and an organic pigment.

The oxalic acid complex salt and its hydrate have the formula M
¹ _a [M ² _b (C ₂ O ₄ ) _c ] .dH ₂ O (In the formula, M ¹ is hydrogen, an alkali metal or an alkaline earth metal, and M ² is C.
r, Mn, Co, Ni, Cu, Mo, Pb or Bi, a, b,
c is an irreversible thermochromic pigment represented by a number of 1 to 3 and a number of d ≧ 0. Specifically, K ₃ [Co (C ₂ O ₄ ) ₃ ].
3H ₂ O, KBa [Cr (C ₂ O ₄ ) ₃ ], K ₂ [Cu (C ₂
O ₄ ) ₂ ].

Oxalic acid metal salt, metal hydroxide, basic carbon
Acid metal salts, metal phosphate salts, and hydrates thereof have the formula
 M^Three _eA_f・ GH_TwoO (in the formula, M^ThreeIs the above M^TwoSame as,
A is C_TwoO_Four, OH, CO_ThreeOr PO_Four, E, f are 1
An irreversible thermochromic pigment represented by the number 3 and the number g ≧ 0)
is there. Specifically as oxalic acid metal salt and its hydrate
Is CoC_TwoO _Four・ 2H_TwoO, NiC_TwoO_Four・ 2H_TwoO,
4NiC_TwoO_Four・ CoC_TwoO_Four・ 10H_TwoO, CuC_TwoO
_Four・ 1 / 2H_TwoO, PbC_TwoO_Four, Bi (C_TwoO_Four)_Three・ 4
H_TwoO, Bi_Two(C_TwoO_Four)_Three・ 7H_TwoO is mentioned.
Specifically as the metal hydroxide, Cu (OH)_TwoAre listed
Be done. Specific as basic metal carbonate and its hydrate
Is 2CoCO_Three・ 3Co (OH)_TwoIs mentioned. Re
Specific examples of the metal acid salts and hydrates thereof include Co_Three
(PO_Four)_Two・ 8H_TwoO is mentioned.

Ammonium metal salts have the formula (NH ₄ ) M
It is an irreversible thermochromic pigment represented by ⁴ (P ₂ O ₇ ) (wherein M ⁴ is the same as M ² ). Specifically, NH ₄ Mn
P ₂ O ₇ and the like.

The ammonia complex salt and its hydrate have the formula
M⁵ _j[M⁶ _k(NH_Three)_m(CO_Three)_n]_oB_p・ QH_TwoO
(In the formula, M⁵Is the above M ¹Same as M⁶Is the above M^TwoSame as
Same, B is NO_Three, PO_Four, P_TwoO₇Or C_TwoO_Four, J,
n is a number from 0 to 1, k is a number from 1 to 2, m is a number from 4 to 6,
i, i is an irreversibility expressed by a number of 1 to 3 and a number of q ≧ 0.
Is a thermochromic pigment. Specifically, [Co (NH_Three)_FourCO
_Three] NO_Three, [Co (NH_Three)₆]_Two(C_TwoO_Four)_Three・ 4H
_TwoO, [Co (NH_Three) ₆] HP_TwoO₇, [Co (NH_Three)₆]
PO_Four・ 4H_TwoO, [Co (NH_Three)_FourCO_Three] NO_Three・ 1 /
2H_TwoO is mentioned. Paraffin is a solid temperature indicator.
Wax, solid fat, non-volatile oil, and / or
When it contains semi-solid fats, ammonia complex salts or
And its hydrate have the formula w (NH_Four)_TwoOM⁷ _xO_y・ ZH
_TwoO (in the formula, M⁷Is the above M^TwoSame as or Al, w is positive
, X and y are numbers from 1 to 3 and z ≧ 0)
It may be a reversible thermochromic pigment. Specifically, 3 (NH
_Four)_TwoO ・ Al_TwoO_Three・ 12 MoO_Three・ 19H_TwoO
Be done.

Addition of hexamethylenetetramine to metal salts
Additives and hydrates thereof have the formula M⁸ _rD_s・ T (CH_Two)
₆N_Four・ UH_TwoO (in the formula, M⁸Is the above M^TwoSame as
Cl, Br, I, SO_Four, NO_ThreeOr SCN, r, s is 1
To 3; t is a number from 2 to 4; u ≧ 0)
It is a reversible thermochromic pigment. Specifically, CoCl_Two・ 2
(CH_Two)₆N_Four・ 10H_TwoO, 4 / 5CoBr_Two・ 1/5
NiBr_Two・ 2 (CH_Two)₆N_Four・ 10H_TwoO, CoI_Two・
2 (CH_Two)₆N_Four・ 10H_TwoO, Co (NO_Three)_Two・ 2 (C
H_Two)₆N_Four・ 10H_TwoO, Co (SCN)_Two・ 2 (CH_Two)
₆N_Four・ 10H_TwoO, NiCl_Two・ 2 (CH_Two)₆N_Four・ 1
0H_TwoO, [5 / 6Co (NO_Three)_Two・ 1/6 Ni_Two(NO
_Three)_Two] ・ 2 (CH_Two)₆N_Four・ 10H_TwoO, CoSO_Four・ 2
(CH _Two)₆N_Four・ 9H_TwoO is mentioned.

The metal salt of tetraiodomercuric acid has the formula Ag _v
It is a reversible thermochromic pigment represented by Cu _2−v HgI ₄ (wherein the number is 2 ≧ v ≧ 0). For example, Ag ₂ HgI ₄ , A
g _1.6 Cu _0.4 HgI ₄ , Ag _{0 . 3} Cu _1.7 H
gI ₄ and CuHgI ₄ may be mentioned.

Examples of the organic pigment include phthalocyanine blue.

The solid temperature indicating material changes its color when it is exposed to a predetermined temperature, because these thermochromic pigments have a change in crystal structure, desorption of hydration water contained therein, or decomposition. Because I will do it. The degree of discoloration of the thermochromic pigment depends on the heating temperature and the heating time.

By selecting this thermochromic pigment appropriately,
A solid temperature indicating material whose color tone changes at a desired temperature is obtained, which is used for detecting overheating of a device such as a motor and for confirming a temperature history. When the thermochromic pigment is irreversible, it can be stored in the changed color tone. When the thermochromic pigment is reversible, the display material can be repeatedly used.

When the solid temperature indicating material is heated at a constant temperature for 4 seconds, the discoloration start temperature, that is, the 4 second discoloration point is 20.
The temperature indicating material in which the thermochromic pigment is selected so as to be 0 ° C. or higher can be preferably used for controlling the temperature between passes when welding the steel frame steel. FIG. 1 is a view showing a state in which steel-framed steel materials 1 and 3 are being multi-layer welded using a backing metal 2. When the weld metal layer 4 is continuously formed, the interpass temperature is easily higher than 500 ° C., so that a part of the steel material affected by the welding heat or the weld metal affected by the welding heat has a reduced toughness. In addition, as a result of causing metallurgical discontinuity with the base metal, sufficient welding strength cannot be obtained. Therefore, it is necessary to perform the next pass, that is, the weld metal layer forming work, after lowering the temperature between predetermined passes. A solid temperature indicating material is used to determine whether or not welding was performed in compliance with a predetermined interpass temperature and the interpass temperature was properly controlled. Specifically, the calibration line 10 drawn vertically with a temperature display material from the welded portion is
Since the color changes by a predetermined length L depending on the temperature between passes, the length L is used to confirm whether the welding has been performed at a predetermined temperature.

If a temperature indicating material having a color change point of less than 200 ° C. for 4 seconds is used, the entire length of the drawn inspection line will be discolored regardless of whether the temperature control between passes is performed or not, so that it is not possible to sufficiently confirm the welding failure. .

The temperature of the test object can also be detected by drawing a line on the preheated test object and measuring the time until the color changes to a predetermined color tone. it can.

The oxalic acid complex salt as thermochromic pigments, oxalic acid metal salt or a hydrate thereof, among others _CoC 2 _O 4 · 2
In the temperature display material using H ₂ O or NiC ₂ O ₄ .2H ₂ O, the color change boundary between the color change area and the non-color change area of the inspection line 10 becomes clear, and the color change of the inspection line 10 occurs during the temperature control between passes. Since the length L can be accurately measured, reliable temperature control between passes can be performed.

The binding inorganic compound is preferably gypsum, bentonite or water glass. When the solid temperature indicating material contains a binding inorganic compound, it becomes possible to draw the line more easily regardless of the temperature and smoothness of the surface of the test object.

The solid temperature indicating material may further contain a white pigment and an extender.

Since the white pigment hides the color of the surface of the test object, the color tone before and after the color change of the thermochromic pigment can be clearly displayed, and examples thereof include zinc oxide and titanium oxide.

The extender is a colorless or white substance which is added mainly for the purpose of increasing the amount, and examples thereof include calcium carbonate, barium sulfate, talc, alumina, and silicon dioxide.

The temperature indicating material used for controlling the temperature between passes is 2 to 60% by weight of the thermochromic pigment, preferably 5 to 5%.
0% by weight and paraffin wax 35 to 60% by weight,
Mineral wax, wood wax, beeswax and tallow as solid fats and oils 1
10 to 10% by weight, preferably 1 to 5% by weight, and 0.05 to 2% by weight of animal oil, vegetable oil, mineral oil, liquid paraffin or petrolatum as a non-volatile oil and / or semi-solid fat.
Preferably, it contains 0.05 to 1% by weight and 0 to 62% by weight of the white pigment and / or the extender. Thermochromic pigments _{CoC 2 O} 4 · 2H 2 _O and _NiC 2 _{O 4} ·
2H ₂ O is particularly preferably used. Since this solid temperature indicating material contains solid oil and fat, and non-volatile oil and / or semi-solid oil and fat, it has excellent adhesiveness and fixability and can be reliably tested on a smooth metal surface at room temperature. Lines can be drawn and writing is good. Further, when the solid fats and oils are limited to the above range and used, they are not affected by scorching and the discolored boundary is clear.

Another embodiment of the solid temperature indicating material is 2 to 60% by weight of the thermochromic pigment and 0.5 to 0.5% of the binding inorganic compound.
98% by weight and 0 to 9 of white pigment and / or extender
7.5% by weight. Thermochromic pigment is C
oC ₂ O ₄ .2H ₂ O and NiC ₂ O ₄ .2H ₂ O are particularly preferably used. This solid temperature display material can reliably draw a calibration line regardless of the steel surface temperature, and has a clear discoloration boundary.

Still another embodiment of the solid temperature indicating material is
3 to 55% by weight of thermochromic pigment, preferably 5 to 50% by weight
And 2 to 20% by weight of paraffin wax, which has no binding property.
0 to 10% by weight of organic compound, white pigment and / or
It contains 15 to 95% by weight of the extender.
Thermochromic pigment is CoC_TwoO_Four・ 2H_TwoO and NiC_TwoO_Four・ 2H
_TwoO is particularly preferably used. This solid temperature display material
60 ~ 120 ℃ as when welding large steel
Especially good for writing preheated steel. Also,
It is soft to the touch and does not stain your fingers.

[0036]

EXAMPLES Examples of the solid temperature indicating material of the present invention will be described in detail below.

Examples 1 to 10 show examples of trial production of solid temperature indicating materials to which the present invention is applied, and Comparative Examples 1 to 2 show trial production of temperature indicating materials to which the present invention is not applied. Indicates.

Paraffin waxes, solid fats and oils, binding inorganic compounds, non-volatile oils, semi-solid fats and oils, white pigments and / or extenders shown in Tables 1 and 2 were kneaded with a thermochromic pigment. When using an inorganic compound, water was added as needed. It was squeezed or poured into a mold to obtain a solid temperature indicating material.

[0039]

[Table 1]

[0040]

[Table 2]

Prototype Examples 1 to 10 and Comparative Examples 1 to 1
The physical properties of the solid temperature indicating material of No. 2 were examined.

First, each temperature indicating material was placed in a constant temperature bath at 50 ° C. and observed for melting and seeping out of solid fats and oils or semi-solid fats and oils when stored for 2 hours.

Next, when the lines were drawn separately on two types of flat metal plates heated at room temperature and 80 ° C. with each solid temperature display material, the one with excellent writing quality was marked with ⊚, and the good one was marked with ○. It was evaluated on a three-point scale, where the bad ones were marked x.

Next, the drawn metal plate was placed on a temperature-adjustable heater and heated, and changes in the color tone of the drawn line and the presence or absence of charring were observed.

When the temperature indicating material was heated at a constant temperature by the heater, the temperature at which discoloration started 4 seconds later was measured as a 4 second discoloration point.

Next, the suitability of use for controlling the temperature between passes when welding steel materials with multiple layers of weld metal was examined. As shown in FIG. 1, a test line 10 orthogonal to the welding site was drawn on the steel material to be actually welded.
Verification between the case where welding is performed while strictly controlling the interpass temperature by the thermocouple 11 installed at a position separated by a fixed distance R, for example, 10 mm from the welding site, and the case where welding is performed without controlling the interpass temperature. It was observed whether the difference in the discolored length L of line 10 was clear. Further, when the steel material having the surface temperature of the room temperature and the temperature of 80 ° C. were drawn with the calibration line 10 and then welded, the clearness of the boundary between the discolored area and the undiscolored area was observed. The evaluation was made on a 4-point scale, in which the clear one was ◯, the slightly clear one was Δ, and the unclear one was x. Regarding the suitability for use as a temperature control between passes, the one in which the difference in the discolored length was clear and the boundary of the discoloration was clear was evaluated as suitable, and the others were evaluated as unsuitable.

As shown in Table 1, all of the solid temperature indicating materials of Examples 1 to 10 have a good writing quality, no melting or bleeding after storage, and a calibration line drawn during welding. Was clearly discolored for an appropriate length. Therefore, these temperature display materials can be used for overheat detection and temperature history confirmation. In particular, the temperature indicating materials of Examples 4 to 10 can be suitably used for controlling the temperature between passes.

On the other hand, as shown in Table 2, since the temperature indicating material of Comparative Example 1 was scorched by heating, a clear discoloration could not be confirmed, and the temperature indicating material of Comparative Example 2 was bleeding with oil or fat after storage. It was out.

[0049]

As described above in detail, the temperature indicating material of the present invention is in a solid state and can be surely and easily drawn on the steel material to be welded even at room temperature. This temperature indicating material does not require a complicated operation of applying and drying like a paint.

This temperature indicating material is used when detecting overheating of a device such as a motor which should avoid overheating or checking the temperature history. Further, it can be used for confirming whether the steel reaches a predetermined inter-pass temperature when welding the steel.

The line drawn by the temperature display material changes its color clearly when exposed to a predetermined temperature and displays the temperature easily and accurately.

[Brief description of drawings]

FIG. 1 is a diagram showing a process of multi-layer welding of steel materials.

[Explanation of symbols]

1 and 3 are steel materials, 2 is a backing metal, 4 is a weld metal layer, 5 is a welded portion, 10 is a calibration line, 11 is a thermocouple for measuring inter-pass temperature, L is a discoloration length, and R is from a welded portion. Is the distance.

Claims (5)

[Claims] 1. A solid temperature indicating material comprising at least one kind of thermochromic pigment which is discolored by heat and paraffin wax and / or a binding inorganic compound. 2. A solid oil or fat which is a mineral wax, a wood wax, a beeswax and / or a tallow, a non-volatile oil which is an animal oil, a vegetable oil, a mineral oil and / or a liquid paraffin, and a semi-solid oil or fat which is a petrolatum. The solid temperature indicating material according to claim 1, characterized in that at least one kind thereof is contained. 3. The solid fats and oils of 1 to 10% by weight and the non-volatile oil and the semisolid fats and oils in a total amount of 0.05 to 2% by weight are contained. The solid temperature display material described. 4. The thermochromic pigment comprises an oxalic acid complex salt, an oxalic acid metal salt, a metal hydroxide, a basic metal carbonate, a metal phosphate, an ammonium metal salt, an ammonia complex salt, and hexamethylenetetramine to a metal salt. The solid temperature indicating material according to claim 1, which is selected from an adduct, a metal salt of tetraiodomercuric acid, a hydrate thereof, and an organic pigment. 5. The solid temperature indicating material according to claim 1, wherein the binding inorganic compound is gypsum, bentonite or water glass.