JP2017220517A - Self temperature control type resin resistor paste composition and self temperature control type resin resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self temperature control type resin resistor paste composition for forming a thin film having a self temperature control function in a temperature region of 150-300°C by optimizing materials and compositions of three types of a resin, conductive powder and an inorganic filler, and to provide a self temperature control type resin resistor using the paste composition.SOLUTION: A self temperature control type resin resistor paste composition contains an uncured liquid made of an uncured liquid resin, conductive powder and an inorganic filler, where the uncured liquid is any one of an uncured thermosetting resin, a liquid obtained by dissolving the thermosetting resin in an organic solvent, a liquid obtained by dissolving a thermoplastic resin having a glass transition point of 250°C or higher in an organic solvent, and a liquid obtained by dissolving a mixture of the thermosetting resin and the thermoplastic resin in the organic solvent, an inorganic filler to be contained is plate-like powder, and a content of the inorganic filler is 3-20 vol.% with respect to the volume of a self temperature control type resin resistor being a cured product of a self temperature control type resin resistor paste.SELECTED DRAWING: Figure 1

Description

  In the present invention, the temperature at which the rate of increase in the resistance value when the self-temperature-regulating resin resistor is heated and the temperature of the atmosphere is increased (hereinafter also referred to as self-regulating temperature) is 150 ° C. The present invention relates to the above self-temperature-controlling resin resistor, and also relates to a self-temperature-controlling resin resistor paste composition for forming the self-temperature-controlling resin resistor.

  A conductive composition in which a conductive material such as carbon black or metal powder is dispersed in an organic polymer such as polyethylene or polypropylene has a resistance value that changes with temperature, and the resistance value increases. PTC (positive temperature coefficient) It is known to have properties. Such a composition is disclosed in Patent Document 1.

An element having such a PTC characteristic (hereinafter referred to as a PTC element) has an excessive current flowing in the PTC element, and when the temperature of the PTC element itself reaches a certain temperature T ₀ (inflection point), or When the environmental temperature of the device rises and the temperature of the PTC element reaches T ₀ , the PTC element suddenly becomes a high resistance (trip state), thereby interrupting the current flowing through the element, thereby incorporating the PTC element. It is used as a protection circuit that protects electrical circuits.

  By utilizing the PTC characteristics, the conductive composition has the function of maintaining the set (material design) temperature, and has been commercialized and marketed by various manufacturers as a ribbon-like or film-like flexible heater as a self-temperature control heater. ing.

By the way, in a trip state higher than the inflection point T ₀ , the polymer softens or expands, the conductive material moves, and the resistance value increases. And if the temperature of a PTC element falls from an inflection point, softening and expansion | swelling of a polymer will be eliminated, and since a conductive material re-aggregates, resistance value will fall. Depending on the PTC element, it may be necessary to set the inflection point to 150 ° C. or higher.
Therefore, Patent Document 2 discloses a technique of a temperature self-controllable molded body made of non-thermoplastic polyimide and conductive powder as a PTC resistor that operates at a high temperature of 150 ° C. or higher.
However, in the technique disclosed in Patent Document 2, since the inflection point is controlled by changing the molecule of the polyimide resin, there is a problem that the degree of freedom of design when assuming the inflection point is low.

  In addition, products with similar characteristics are being marketed with ceramic heaters that use resistance change characteristics at the Curie point of barium titanate. However, with a ceramic heater, it is difficult to freely select the shape of the self-temperature-controlling resin resistor.

Japanese Patent Publication No. 55-012683 JP 2006-173586 A

  Conventionally, in a trip state at a high temperature of 150 ° C. or higher, the polymer softens and the conductive material easily moves, and changes such as a decrease in resistance value due to re-aggregation cause self-temperature-adjustable resin that exhibits stable PTC characteristics There is a problem that it is difficult to obtain a resistor. In addition, it is necessary to design a molecule for the self-temperature-regulating resin resistor that operates at an inflection point of 150 ° C. or higher.

  In view of the above situation, the present invention forms a thin film having a self-temperature control function in a temperature range of 150 to 300 ° C. by optimizing three types of materials and composition of resin, conductive powder, and inorganic filler. The self-temperature-controlling resin resistor paste composition is provided, and a self-temperature-controlling resin resistor using the paste composition is provided.

A first invention of the present invention is a self-temperature-regulating resin resistor paste composition, which includes an uncured liquid material that is an uncured liquid resin, a conductive powder, and an inorganic filler, and the uncured liquid material Are “uncured thermosetting resin”, “liquid in which uncured thermosetting resin is dissolved in an organic solvent”, “liquid in which a thermoplastic resin having a glass transition point of 250 ° C. or higher is dissolved in an organic solvent”, It is one of “a liquid obtained by dissolving a mixture of an uncured thermosetting resin and a thermoplastic resin having a glass transition point of 250 ° C. or higher in an organic solvent”, and the contained inorganic filler is a plate-like powder. A self-temperature-controlling resin characterized in that the content is 3 to 20% by volume of the volume of the self-temperature-controlling resin resistor, which is a cured product of the self-temperature-controlling resin resistor paste It is a resistor paste composition.
In addition, “an uncured thermosetting resin, a thermoplastic resin having a glass transition point of 250 ° C. or higher, or a liquid obtained by dissolving any mixture thereof in an organic solvent” may be hereinafter also referred to as “varnish”.

  According to a second aspect of the present invention, the conductive powder according to the first aspect of the present invention has a content such that the conductive powder is 5 to 20% by volume of the volume of the self-temperature-adjustable resin resistor. A self-temperature-regulating resin resistor paste composition characterized in that it is contained.

  According to a third aspect of the present invention, there is provided a self-temperature-controlling resin resistor paste composition, wherein the conductive powder in the first and second aspects is either a metal powder or a non-metal powder, or both. It is a thing.

  According to a fourth aspect of the present invention, the inorganic filler according to the first to third aspects is a layered clay mineral selected from boron nitride, bentonite, mica, and kaolin. It is a resin resistor paste composition.

  The fifth invention of the present invention is an epoxy resin if the resin contained in the uncured liquid material in the first to fourth inventions is a thermosetting resin, and a polyamide-imide resin if it is a thermoplastic resin. Is a self-temperature-regulating resin resistor paste composition.

  6th invention of this invention, when the metal powder is contained in the electroconductive powder in 3rd invention, the metal powder is either nickel powder, nickel-type alloy powder, or nickel-type coat powder, It is characterized by the above-mentioned. Is a self-temperature-controlling resin resistor paste composition.

  In a seventh aspect of the present invention, when the conductive powder in the third aspect includes a non-metallic powder, the non-metallic powder is selected from the group consisting of carbon black powder, titanium nitride powder, and zirconium nitride powder. A self-temperature-controlling resin resistor paste composition, characterized in that it is at least one powder.

  An eighth invention of the present invention is a self-temperature-controlling resin resistor having PTC characteristics in which a conductive substance is dispersed in a resin, the resin being a thermosetting resin and a glass transition point of 250 ° C. or higher. A plate which is either or both of a plastic resin and contains 5 to 20% by volume of the volume of the self-temperature-adjustable resin resistor, and 3 to 20% by volume of the volume of the self-temperature-adjustable resin resistor A self-temperature-controlling resin resistor comprising an inorganic filler in the form of a powder.

  According to a ninth aspect of the present invention, there is provided a self-temperature-controlling resin resistor characterized in that the conductive substance in the eighth aspect is a conductive powder and is a metal powder, a non-metallic powder, or both.

  In a tenth aspect of the present invention, the inorganic filler in the eighth and ninth aspects is boron nitride, or at least one layered clay mineral selected from bentonite, mica, and kaolin. It is an adjustment type resin resistor.

  The eleventh invention of the present invention is characterized in that the resin in the eighth to tenth inventions is an epoxy resin if it is a thermosetting resin, and is a polyimide resin or a polyamide-imide resin if it is a thermoplastic resin. Self-regulating resin resistor.

  In a twelfth aspect of the present invention, when the conductive powder in the ninth aspect includes a metal powder, the metal powder is any one of a nickel powder, a nickel-based alloy powder, and a nickel-based coated powder. It is a temperature control type resin resistor.

  In a thirteenth aspect of the present invention, when the conductive powder in the ninth aspect includes a nonmetallic powder, the nonmetallic powder is at least selected from the group consisting of carbon black powder, titanium nitride powder, and zirconium nitride powder. A self-temperature-controlling resin resistor characterized by being one type of powder.

  In a fourteenth aspect of the present invention, the self-temperature-regulating resin resistor according to the eighth to thirteenth aspects is characterized in that a self-regulating temperature at which the rate of increase in resistance value due to temperature rise changes is 150 ° C. or higher. It is a self-temperature adjusting type resin resistor.

  According to the present invention, a self-regulating resin resistor that can control the self-regulating temperature in a temperature range of 150 ° C. to 300 ° C. is realized by selecting the resin and selecting the content ratio of the conductive powder and the inorganic filler. it can.

It is a figure which shows the "electric resistance-temperature characteristic" of the self-temperature adjustment type | mold resin resistor which concerns on Example 1 of this invention, and represents the evaluation method of self temperature adjustment temperature. FIG. 6 is a diagram showing “electric resistance-temperature characteristics” according to Example 2. FIG. 6 is a diagram illustrating “electric resistance-temperature characteristics” according to Example 3; 6 is a diagram showing “electric resistance-temperature characteristics” according to Comparative Example 1. FIG. FIG. 10 is a diagram showing “electric resistance-temperature characteristics” according to Comparative Example 5;

[Self-adjusting resin paste composition]
In the present invention, when obtaining a self-temperature-regulating resin resistor paste composition, a single composition of epoxy, polyamideimide, and polyimide, or a mixture of organic polymers, a conductive material such as carbon black or metal powder. It is necessary to form a conductive composition by dispersing a substance, and as a substance for improving its electrical characteristics, a predetermined amount adjusted with the content of the conductive powder is further added to the plate-like crystal or plate-like inorganic filler. A self-temperature-controlling resin resistor paste composition is prepared by adding to form a conductive composition.

  Regarding the mechanism of the effect of improving the electrical properties due to the addition of this plate-like crystal or plate-like inorganic filler, the presence of the plate-like inorganic filler uniformly between the conductive materials will result in the trip state of the conductive material. The effect of suppressing re-aggregation in can be considered.

[Inorganic filler]
As an inorganic filler to be used, it may be a plate-like crystal or plate-like form, and boron nitride is particularly desirable, but a layered clay mineral is also preferred. Examples of the layered clay mineral include bentonite, mica, and kaolin.
Also useful are organic bentonites of clay minerals with organic modifications.

Both of these inorganic fillers and layered clay minerals are plate-like powders. In the self-temperature-regulating resin resistor according to the present invention, the inorganic fillers of this plate-like powder are oriented and dispersed in the resistor substantially in one direction. ing. Therefore, the orientation direction affects the heat generation of the self-temperature-controlling resin resistor and the manner of thermal expansion when the self-temperature-controlling resin resistor is exposed to heat.
Therefore, the self-adjusting temperature can be set to 150 ° C. or higher by the influence of the orientation direction of the plate-like inorganic filler and the selection of the resin.

When boron nitride powder is used as the inorganic filler to be used, the particle size distribution is preferably 0.01 μm to 20 μm at d ₅₀ . On the other hand, when the average particle diameter of the boron nitride powder exceeds 20 μm, it is difficult to obtain the effect of the PTC characteristics. Here, the particle size distribution d ₅₀ is a median value of the particle size distribution measured using a laser diffraction / scattering type particle size distribution measuring apparatus.
The particle size of the layered clay mineral is 2 μm or less in the major axis direction.

The self-temperature-regulating resin resistor according to the present invention adjusts the self-regulating temperature based on the content of the inorganic filler.
As the content of the inorganic filler increases, the self-adjusting temperature tends to increase. However, the self-temperature-adjusting resin resistor, which is a cured product of the self-temperature-adjusting resin resistor paste composition, exceeds 20% by volume of the inorganic filler. If it is contained, the resistance value of the self-temperature-controlling resin resistor exceeds 10 ⁷ Ω and is too high to form a PTC element. On the other hand, when the content of the inorganic filler is less than 3% by volume, the self-adjusting temperature is confirmed, but the resistance value has a peak at a temperature exceeding the self-adjusting temperature, and the resistance value decreases at a temperature higher than the peak temperature. It will not function as a PTC element.

[Conductive powder]
The conductive powder may be composed of metal powder, non-metal powder, or both. As for the content rate of the electroconductive powder, it is desirable that 5-20 volume% is contained in the self-temperature-controlling resin resistor.
When the content of the conductive powder is less than 5% by volume, a self-adjusting temperature is generated at a temperature of 150 ° C. or higher. However, the resistance value is 4 in a temperature range from 40 ° C. to 40 ° C. It does not rise twice and does not function as a PTC element. On the other hand, when the content of the conductive powder is less than 5% by volume, the obtained resistance value exceeds 10 ⁷ Ω and is too high to function as a PTC element.
On the other hand, when the conductive powder is contained in an amount exceeding 20% by volume, a self-adjusting temperature is generated at a temperature of 150 ° C. or higher, but in a temperature range of 40 ° C. from the temperature at which the ratio of the resistance value increase to the temperature rise changes. The resistance value does not increase four times and does not function as a PTC element.

<Metal powder>
When metal powder is used for the conductive powder, nickel powder, copper powder, platinum powder, silver powder, cobalt powder, nickel alloy powder, silver alloy powder, or nickel coat powder can be used. In particular, nickel powder, nickel alloy powder, and nickel coat powder are desirable.
A nickel-chromium alloy or a nickel-copper alloy can be used as the nickel-based alloy powder. A silver-palladium alloy can be used as the silver alloy.

The particle size of the metal powder used is 0.1 μm to 10 μm as primary particles, and the particle size of the primary particles is particularly preferably 0.1 μm to 3 μm. Furthermore, it is desirable that the metal powder forms secondary particles in which primary particles are aggregated.
When using a metal powder of secondary particles in which such primary particles are aggregated, the particle size distribution d50 of the secondary particles is desirably ₅ μm to 60 μm, and when the particle size of the secondary particles exceeds 60 μm, When the metal powder is not sufficiently dispersed, the resistance value becomes too high or the self-adjusting temperature may not be exhibited. On the other hand, if the particle size of the secondary particles is less than 5 μm, the metal powder is less aggregated, so that the number of intertwined portions is reduced, and the resistance value after kneading with the resin may be increased.

  The particle size of primary particles is the particle size of individual particles that are aggregated, and is measured by SEM observation. Alternatively, the SEM image may be image-analyzed to calculate the average particle size to obtain the particle size. Further, it may be obtained from a particle size distribution measured using a laser diffraction / scattering particle size distribution measuring apparatus.

<Non-metallic powder>
As the conductive powder, in addition to the metal powders described so far, conductive non-metal powders such as carbon black, titanium nitride, and zirconium nitride can also be suitably used.

Metal powder is preferably the particle size distribution _{d 50} of used ones 0.005～100Myuemu, it is particularly preferable to particularly use those 0.01μm~60μm with a particle size distribution _{d 50.}
If the particle size distribution d ₅₀ is less than 0.005 μm, mixing becomes difficult, and if it exceeds 100 μm, the resistance may be increased.

[resin]
As the resin used for the self-temperature-controlling resin resistor, a thermosetting resin, a thermoplastic resin having a glass transition point of 250 ° C. or higher, or a mixture composed of both is used.
Even when the thermosetting resin is exposed to a temperature exceeding the glass transition point, it can maintain its shape without being softened until it is thermally decomposed. For such a thermosetting resin, an epoxy resin is preferable from the viewpoint of heat resistance and the like. Moreover, the glass transition point of an epoxy resin can be suitably selected from a resistance value change at a temperature higher than the self-adjusting temperature.

<Epoxy resin>
Examples of the epoxy resin include various bisphenol-type epoxies, various phenol novolak-type epoxy resins, cresol novolac-type epoxy resins, epoxidized products of various dicyclopentadiene-modified phenol resins obtained by reacting dicyclopentadiene with various phenols, and novolaks. Examples thereof include known aromatic epoxy resins such as modified epoxy derived from a naphthalene skeleton such as modification, and an epoxy resin obtained by epoxidizing a phenol resin having a fluorene skeleton. Moreover, it is possible to use an alicyclic epoxy resin or a known epoxy resin containing a heterocyclic ring.

Examples of the curing agent used in combination include known curing agents such as amine compounds, amide compounds, dibasic acid compounds, acid anhydride compounds, and phenol compounds.
In the amine compound, examples of the amine compound include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole and the like. Examples of amide compounds include dicyandiamide.
Acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydro And phthalic anhydride.
Examples of phenolic compounds include polyhydric phenolic hydroxyl group-containing compounds such as phenol novolac resins, cresol novolac resins, and phenol resins.

A known curing accelerator may be used in combination with the epoxy resin.
Furthermore, in the self-temperature-controlling resin resistor paste composition according to the present invention, an organic solvent that dissolves an uncured epoxy resin or a reactive organic solvent having an epoxy group may be used. For example, esters such as diethylene glycol monoethyl ether acetate can be used as the organic solvent.

The state of these uncured epoxy resins may be liquid or solid pellets. The uncured epoxy resin is dissolved in an organic solvent or the like even in a solid pellet form. Therefore, these uncured epoxy resins may be dissolved in an organic solvent in some cases to constitute an uncured liquid material of an adhesive liquid used in the self-temperature-regulating resin resistor paste composition according to the present invention, It can be used for the self-temperature-controlling resin resistor paste composition according to the present invention.
It is desirable that the epoxy resin used in the self-temperature-regulating resin resistor paste composition can be cured by selecting a curing agent and heating.

<Thermoplastic resin having a glass transition point of 250 ° C. or higher>
For thermoplastic resins having a glass transition point of 250 ° C. or higher, polyimide resins and polyamideimide resins are desirable. Since the polyimide resin and the polyamideimide resin do not deteriorate at a temperature of 150 ° C. to 300 ° C., they can be used for the resin of the self-temperature-controlling resin resistor according to the present invention.

  When a thermoplastic resin is used for the self-temperature-regulating resin resistor paste composition, an adhesive liquid varnish in which polyimide resin or polyamide resin is dissolved in a known ether such as diethylene glycol monoethyl ether acetate as an uncured liquid material Can be used.

  Moreover, in the uncured liquid material, known diethyl ether, ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol-n-propyl ether, ethylene glycol-i-, which dissolves without precipitating the polyamic acid of the polyimide precursor. Ethers such as propyl ether, ethylene glycol-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate And dissolved in esters Varnish uncured liquid was also can be used.

Even if an adhesive liquid varnish in which polyamic acid is dissolved in an organic solvent is used for the uncured liquid, it is converted into a polyimide resin by imidation by heating and dehydrating and ring-closing after applying the self-temperature-regulating resin resistor paste composition. be able to.
In addition, since polyimide resin is known to be cured by being dehydrated and closed by heating, it may be recognized as a thermosetting resin, but in the present invention, polyimide resin is used as a thermoplastic resin. Take as an example.
Moreover, the resin used for the self-temperature-controlling resin resistor according to the present invention may be a mixture of an epoxy resin and a polyimide resin.

[Method for producing self-temperature-adjustable resin resistor paste]
The self-temperature-controlling resin resistor paste can be produced by mixing an inorganic filler, conductive powder, and an uncured liquid with a known mixing method such as a self-revolving mixer, a bead mill, a ball mill, a roll mill, or the like.

[Self-temperature-regulating resin resistor]
The self-temperature-controlling resin resistor according to the present invention can be obtained by applying the self-temperature-controlling resin resistor paste composition according to the present invention to a substrate or the like and curing it by heating.
<Heat drying>
When the self-temperature adjusting resin resistor paste composition is heated, the organic solvent is volatilized, and a dry film of the self-temperature adjusting resin resistor paste composition is formed on the surface of the object to be coated. The process of forming this dry film is called heat drying.

<Heat curing>
When exposed to a temperature higher than this heat drying, if a thermosetting resin is used for the self-temperature-controlling resin resistor paste composition, the curing reaction of the resin proceeds.
When polyamic acid is used for the self-temperature-controlling resin resistor paste composition, imidization proceeds and the self-temperature-controlling resin resistor paste composition is cured.
If a thermoplastic resin such as polyimide dissolved in an organic solvent is used for the uncured resin adhesive of the self-temperature-adjustable resin resistor-forming composition, the organic solvent is further removed and the self-temperature-adjustable resin resistor paste The composition is cured.
The process of curing the self-temperature-controlling resin resistor paste composition as described above is called heat curing.

The heat curing temperature of the self-temperature-regulating resin resistor paste composition needs to be cured at a temperature that is 50 ° C. or higher than the self-regulating temperature. This is because if the resin is cured at a temperature lower than the operating temperature (use temperature), the resin may change during long-term use, and sufficient reliability cannot be obtained. In practice, the temperature change is repeated in a range of about + 20 ° C., so that the temperature may be cured at a temperature of + 20 ° C. or higher.
A terminal can be formed after this hardening and a PTC element can be produced.

The self-temperature-controlling resin resistor is formed by being oriented and dispersed in the direction in which the inorganic filler plate powder is applied when the self-temperature-controlling resin resistor paste composition is applied.
When the applied self-temperature adjusting resin resistor paste composition is cured, it is cured while maintaining the dispersion state of the plate-like powder of the inorganic filler.
In the self-temperature-regulating resin resistor according to the present invention, 3-20% by volume of a thermosetting resin, a plate-like powder of a thermoplastic resin having a glass transition point of 250 ° C. or higher and an inorganic filler is contained, and a conductive powder. 5 to 20% by volume, the self-adjusting temperature is exhibited in a temperature range exceeding 150 ° C., and the resistance value of the self-temperature adjusting resin resistor is within a temperature range obtained by adding 40 ° C. to the self-adjusting temperature. It is possible to realize a self-temperature-regulating resin resistor in which the resistance value is not lowered even when exposed to a higher temperature.

  The self-adjusting temperature is an RT curve indicating the relationship between the resistance value and the temperature, and the temperature at which the change in the rate of increase in the resistance value relative to the temperature when the temperature of the self-temperature adjusting resin resistor is increased starts to change. That is. FIG. 1 shows the RT curve and the self-adjusting temperature.

  Hereinafter, the effects will be described with examples.

As the self-temperature adjusting resin resistor paste composition, an epoxy resin and a curing agent phenol resin were dissolved in an organic solvent diethylene glycol monoethyl ether acetate to prepare an uncured liquid material. In that case, it mixed so that the numerical value of the epoxy equivalent of an epoxy resin and the phenol equivalent numerical value of a phenol resin might correspond.
As the conductive powder, Ni powder having a primary particle size of 1 μm and a secondary particle size distribution d ₅₀ of 10 μm was used, and boron nitride having a particle size distribution d ₅₀ of 2 μm was added to the inorganic filler of the plate-like crystal. A self-regulating resin resistor paste composition was prepared by kneading while defoaming with a kneading machine of the type.

In order to measure the characteristics of the prepared self-temperature-controlling resin resistor paste composition, application was performed using an applicator so that a cured product of 10 mm × 20 mm × (thickness) 100 μm was obtained after curing on a glass substrate. (Hereinafter referred to as RT) to 100 ° C. with a heating time of 1 hour, then cured at a temperature of 350 ° C., and then silver electrodes are formed on both ends in the longitudinal direction to form a self-temperature-controlling resin Resistor resistors were formed.
The resistors according to the examples and the comparative examples were evaluated for “resistance-temperature characteristics” from RT (room temperature) to 300 ° C. in a thermostatic chamber.

The temperature at which self-temperature adjustment in the “resistance-temperature characteristics (hereinafter referred to as RT curve)” evaluation was performed by specifying the temperature of the resistance value change as follows.
An example of the evaluation method and the results according to Example 1 are shown in FIG.
As shown in FIG. 1, in the RT curve, the intersection temperature of the approximate straight line before and after the resistance value change greatly is set as the self-adjusting temperature.
It can be seen that the self-regulating temperature of the paste in Example 1 is 178 ° C.

In addition, self-temperature adjustment is sufficiently possible if the PTC characteristic has a resistance value change of one digit or more in the temperature range of + 40 ° C. from the temperature at which the resistance value change starts. The change starts from 150 ° C., and the resistance value changes by two or more digits in the temperature range of 150 to 190 ° C., so that it can be determined that the PTC characteristic has sufficient temperature adjustment.
Table 1 summarizes the component composition of the self-temperature-controlling resin resistor paste composition according to the example and the measurement results of the PTC characteristics.

Except that the content of the inorganic filler was 14 vol%, a test material was prepared and evaluated for characteristics in the same manner as in Example 1.
The results are shown in Table 1 and FIG.

In Example 3, test materials were prepared and properties were evaluated in the same manner as in Example 1, except that organic bentonite was used instead of boron nitride (BN) as the inorganic filler.
The results are shown in Table 1 and FIG.

In Example 4, a test material was prepared and the characteristics were evaluated in the same manner as in Example 1 except that the content of the conductive powder Ni was 8 vol%.
The results are shown in Table 1.

In Example 5, a test material was prepared and the characteristics were evaluated in the same manner as in Example 1 except that the content of the conductive powder Ni was 13 vol%.
The results are shown in Table 1.

In Example 6, the conductive powder in place of Ni powder particle size distribution d ₅₀ except for using the carbon black of 0.04 .mu.m, the characteristics were evaluated to prepare a test material in the same manner as in Example 1.
The results are shown in Table 1.

In Example 7, except that the particle size distribution d ₅₀ using a titanium nitride 7μm by changing the conductive powder to Ni is, the characteristics were evaluated to prepare a test material in the same manner as in Example 1.
The results are shown in Table 1.

In Example 8, a test material was prepared in the same manner as in Example 1 except that the epoxy resin was replaced with a polyamideimide resin having a glass transition point measured by TMA of 280 ° C. and did not contain a phenol resin as a curing agent. The characteristics were evaluated.
The results are shown in Table 1.

In Example 9, a test material was prepared in the same manner as in Example 1 except that the epoxy resin was changed to a polyimide resin having a glass transition point measured by TMA of 300 ° C. or higher and did not contain a phenol resin as a curing agent. The characteristics were evaluated.
The results are shown in Table 1.

In Example 10, a test material was prepared in the same manner as in Example 1 except that the content of the conductive powder Ni was set to 5 vol%, and the characteristics were evaluated.
The results are shown in Table 1.

In Example 11, a test material was prepared in the same manner as in Example 1 except that the content of the conductive powder Ni was 20 vol%, and the characteristics were evaluated.
The results are shown in Table 1.

In Example 12, test materials were prepared and properties were evaluated in the same manner as in Example 1 except that the content of boron nitride (BN) in the inorganic filler was 3 vol%.
The results are shown in Table 1.

In Example 13, a test material was prepared in the same manner as in Example 1 except that the content of boron nitride (BN) in the inorganic filler was 20 vol%, and the characteristics were evaluated.
The results are shown in Table 1.

(Comparative Example 1)
In Comparative Example 1, a test material was prepared and the characteristics were evaluated in the same manner as in Example 1 except that the content of boron nitride (BN) in the inorganic filler was 2 vol%.
The results are shown in Table 1 and FIG.

(Comparative Example 2)
In Comparative Example 2, a test material was prepared and the characteristics were evaluated in the same manner as in Example 1 except that the content of boron nitride (BN) in the inorganic filler was 25 vol%.
The results are shown in Table 1.

(Comparative Example 3)
In Comparative Example 3, a test material was prepared and the characteristics were evaluated in the same manner as in Example 1 except that the content of organic bentonite in the inorganic filler was 2 vol%.
The results are shown in Table 1.

(Comparative Example 4)
In Comparative Example 4, a test material was prepared and the characteristics were evaluated in the same manner as in Example 1 except that the content of the Ni powder in the conductive powder was 4 vol%.
The results are shown in Table 1.

(Comparative Example 5)
In Comparative Example 5, a test material was prepared and the characteristics were evaluated in the same manner as in Example 1 except that the content of the Ni powder of the conductive powder was 25 vol%.
The results are shown in Table 1 and FIG.

(Comparative Example 6)
In Comparative Example 6, a test material was prepared and the characteristics were evaluated in the same manner as in Example 6 except that carbon black was used as the conductive powder and the content was 25 vol%.
The results are shown in Table 1.

(Comparative Example 7)
In Comparative Example 7, a test material was prepared and the characteristics were evaluated in the same manner as in Example 7 except that titanium nitride was used as the conductive powder and the content was 25 vol%.
The results are shown in Table 1.

(Comparative Example 8)
In Comparative Example 8, the epoxy resin was replaced with a polyamideimide resin having a glass transition point measured by TMA of 280 ° C., and the content of Ni powder in the conductive powder was 25 vol%. Samples were prepared and their characteristics were evaluated.
The results are shown in Table 1.

(Comparative Example 9)
In Comparative Example 9, the epoxy resin was replaced with a polyimide resin having a glass transition point measured by TMA of 300 ° C. or higher, and the content of Ni powder in the conductive powder was 25 vol%. Samples were prepared and their characteristics were evaluated.
The results are shown in Table 1.

(Comparative Example 10)
In Comparative Example 10, a thermoplastic resin polyethylene (glass transition point of TMA measurement—20 ° C.) was used as the resin, and thus a self-temperature-controlling resin resistor paste composition could not be produced.
Therefore, the resin, conductive powder, and inorganic filler shown in Table 1 are kneaded at a temperature of 180 ° C. with a resin kneader, processed into a sheet having a thickness of 0.5 mm, and punched into a size of 3 mm × 4 mm. Was attached to produce a self-temperature-regulating resin resistor.
The PTC characteristic of the resistor of the obtained self-temperature-controlling resin resistor according to Comparative Example 10 was measured.
The self-adjusting temperature was less than 150 ° C. The results are shown in Table 1.

As is apparent from Table 1, in Examples 1 to 13 according to the present invention, it is understood that good PTC characteristics are obtained for both the self-adjusting temperature and the resistance value change.
On the other hand, when the inorganic filler boron nitride (Comparative Example 1) or organic bentonite (Comparative Example 3) is 2 vol%, the effect of addition is not observed. On the other hand, when 25% is contained (Comparative Example 2), the resistance value becomes too high. As a result, the PTC characteristics are not exhibited.
Further, when the amount of conductive powder (Ni powder) was as small as 4 vol% (Comparative Example 4), the resistance value was too high and PTC characteristics were not exhibited. On the other hand, in Comparative Examples 5, 8 to 10 (Ni powder), Comparative Example 6 (carbon black), and Comparative Example 7 (titanium nitride) with a high conductive powder of 25 vol%, a sufficient effect can be obtained in the “resistance value change”. There wasn't.
Furthermore, in Comparative Example 10 in which a polyethylene resin was used as the resin, sufficient effects were not obtained for both “self-adjusting temperature” and “resistance value change”.

Claims (14)

A self-temperature-regulating resin resistor paste composition,
Including an uncured liquid that is an uncured liquid resin, a conductive powder, and an inorganic filler,
The uncured liquid is
Uncured thermosetting resin, liquid in which the thermosetting resin is dissolved in an organic solvent, liquid in which a thermoplastic resin having a glass transition point of 250 ° C. or higher is dissolved in an organic solvent, the thermosetting resin and the thermoplastic resin Is a liquid obtained by dissolving a mixture of the above in an organic solvent,
The inorganic filler is a plate-like powder,
The content of the inorganic filler is included so as to be 3 to 20% by volume of the volume of the self-temperature-controlling resin resistor, which is a cured product of the self-temperature-controlling resin resistor paste. Self-regulating resin resistor paste composition.   2. The self-temperature-adjusting resin resistor paste is contained in the self-temperature-adjusting resin resistor paste at a content rate such that the conductive powder is 5 to 20% by volume of the volume of the self-temperature-adjusting resin resistor. A self-temperature-controlling resin resistor paste composition as described in 1.   The self-temperature-controlling resin resistor paste composition according to claim 1 or 2, wherein the conductive powder is one of or both of a metal powder and a non-metal powder.   The self-temperature-regulating resin resistor according to any one of claims 1 to 3, wherein the inorganic filler is one type of layered clay mineral selected from boron nitride, bentonite, mica, and kaolin. Paste composition.   If the resin contained in the uncured liquid material is a thermosetting resin, it is an epoxy resin, and if it is a thermoplastic resin, it is a polyimide resin or a polyamide-imide resin. A self-temperature-controlling resin resistor paste composition as described in the item.   The self-temperature-controlling resin according to claim 3, wherein when the conductive powder includes a metal powder, the metal powder is any one of a nickel powder, a nickel-based alloy powder, and a nickel-based coated powder. Resistor paste composition.   When the conductive powder contains a nonmetallic powder, the nonmetallic powder is at least one powder selected from the group consisting of carbon black powder, titanium nitride powder, and zirconium nitride powder. Item 4. The self-temperature-controlling resin resistor paste composition according to Item 3. A self-temperature-regulating resin resistor having PTC characteristics in which a conductive substance is dispersed in a resin,
The resin is either a thermosetting resin, a thermoplastic resin having a glass transition point of 250 ° C. or higher, or both, and the conductive material is 5 to 20% by volume of the self-temperature-regulating resin resistor. Including
A self-temperature-controlling resin resistor comprising a plate-like powder inorganic filler in an amount of 3 to 20% by volume of the self-temperature-controlling resistor. The conductive substance is a conductive powder;
The self-temperature-controlling resin resistor according to claim 8, wherein the conductive powder is a metal powder, a non-metal powder, or both.   The self-temperature-controlling resin resistor according to claim 8 or 9, wherein the inorganic filler is at least one layered clay mineral selected from boron nitride, bentonite, mica, and kaolin. If the resin is a thermosetting resin, it is an epoxy resin,
The self-temperature-controlling resin resistor according to any one of claims 8 to 10, wherein the resin resistor is a polyimide resin or a polyamide-imide resin if it is a thermoplastic resin.   The self-temperature-regulating resin resistor according to claim 9, wherein when the conductive powder includes a metal powder, the metal powder is any one of a nickel powder, a nickel-based alloy powder, and a nickel-based coated powder. body.   When the conductive powder includes a non-metallic powder, the non-metallic powder is at least one powder selected from the group consisting of carbon black powder, titanium nitride powder, and zirconium nitride powder. 9. The self-temperature-controlling resin resistor according to 9.   The self-temperature-regulating resin resistor according to any one of claims 8 to 13, wherein a self-regulating temperature at which a rate of increase in resistance value due to temperature rise changes is 150 ° C or higher.

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