TW201625734A - Resin composition, cast product for sensor, and temperature sensor using same - Google Patents

Abstract

The present invention provides a cast molded product for a sensor having excellent thermal shock resistance and moisture resistance, and a resin composition for producing the same. In a resin composition containing an epoxy resin, and a polyoxyalkylene polyamine as a curing agent, the amine equivalent of the polyoxyalkylene polyamine is prescribed at 225 g/eq or less. Furthermore, the amine equivalent of the polyoxyalkylene polyamine is in a range of from 0.40 to 0.75 equivalents per 1 epoxy group equivalent of the epoxy resin. Polyoxypropylene diamine is used as the polyoxyalkylene polyamine.

Description

Resin composition, sensor caster, and temperature sensor

The present invention relates to a resin composition, a castable for a sensor, and a temperature sensor.

Sensors such as temperature sensors are used in a wide range of fields such as automobiles, home appliances, and industrial equipment. For example, as a thermistor temperature sensor, it is known that a thermistor element to which an insulated electric wire is connected is inserted into a protective case (box), and an insulating liquid resin such as an epoxy resin is injected into the protective case, and Its hardened resin model thermistor sensor.

In recent years, the use environment of these sensors has become more stringent, and the requirements for sensor reliability have also increased. The thermistor sensor needs to be deteriorated in the resin portion under such strict use conditions, and no interfacial peeling occurs between the resin portion and the electric wire, thereby maintaining high reliability.

Patent Document 1 discloses that (A) 100 parts by mass of the bisphenol A type epoxy resin, (B) 2 to 20 parts by mass of the flexible epoxy resin, and (C) 2 to 20 parts by mass of the reactive diluent. (D) Amine curing agent 80 to 200 parts by mass and (E) alumina 300 to 500 parts by mass of the resin composition for casting the thermistor sensor. Further, Patent Document 1 discloses that the thermistor element is provided with an insulated wire connected to the thermistor element, and the thermistor element and the outer periphery of the insulated wire are formed by casting. The thermistor sensor of the resin portion formed by the resin composition for the test casting. Further, the thermistor sensor using the above resin composition has high performance and high reliability, and is inexpensive and can be manufactured with good workability.

Patent Document 2 discloses a liquid epoxy resin composition for casting, which comprises an epoxy resin which is liquid at normal temperature, a polyoxypropylene diamine which is a curing agent, and an inorganic filler. The average molecular weight of the polyoxypropylene diamine is in the range of 270 to 1800, and the content of the inorganic filler is 30% by weight or more based on the entire composition. Further, although the liquid epoxy resin composition for casting in Patent Document 2 is a liquid at normal temperature, since the heat generation at the time of curing is small due to low-temperature curing, the casting workability is excellent and the energy cost required for casting is low. Further, it has been shown that since the shrinkage at the time of curing of the castable is extremely small, the obtained cured castable has good dimensional accuracy and is not deteriorated, and has an excellent appearance.

[Patent Document 1] JP-A-2012-59731

[Patent Document 2] JP-A-6-248059

(The means to solve the problem and the effect of the invention)

The above-mentioned sensor casting resin also needs to have excellent adhesion (thermal shock resistance) which does not peel off from the protective case of a copper case or the like during heating and recycling. And the shape retention of the shape can be maintained even in long-term use under high humidity. In particular, regarding shape retention, in recent years, it has been required to maintain the shape for a longer period of time under conditions of higher humidity.

The resin compositions for sensor casting of Patent Documents 1 and 2 have excellent adhesion to the case, but further improvement in shape retention is required.

Accordingly, an object of the present invention is to provide a resin composition capable of maintaining excellent adhesion to a case while further improving shape retention under high humidity conditions, and a temperature sensor and sensing using the resin composition. Casters are used.

As a result of intensive studies, the present inventors have found that the above problems can be solved by specifying the amine equivalent of a polyoxyalkylene polyamine containing a resin composition of an epoxy resin and a polyoxyalkylene polyamine, and completed the present invention.

(1) The resin composition of the present invention is characterized by comprising a resin composition of an epoxy resin and a polyoxyalkylene polyamine, and the polyoxyalkylene polyamine has an amine equivalent of 225 g/eq or less.

(2) Further, the amine equivalent is preferably 200 g/eq or less.

(3) Further, the amine equivalent of the polyoxyalkylene polyamine of the resin composition is preferably in the range of from 0.40 to 0.75 equivalents per equivalent of the epoxy equivalent of the epoxy resin.

(4) The polyoxyalkylene polyamine is preferably a polyoxypropylene diamine.

(5) The resin composition preferably further contains an inorganic filler.

(6) The inorganic filler preferably contains at least one selected from the group consisting of alumina, boron nitride, and tantalum nitride.

(7) The foregoing resin composition is preferably applicable to the pouring of a sensor.

(8) In addition, the temperature sensor of the present invention is characterized in that it comprises a temperature sensor element, a box surrounding the temperature sensor element, and a casting between the temperature sensor element and the box. The above resin composition.

The present inventors have also found that in the castable for a sensor using a resin composition containing an epoxy resin and a polyoxyalkylene polyamine, the boiling water absorption rate of the cured product of the resin composition is adjusted to a certain value. The value can solve the above problems.

(9) That is, the castable for a sensor of the present invention is a caster for a sensor comprising a resin composition containing an epoxy resin and a polyoxyalkylene polyamine, characterized in that the cured product of the above resin composition is The boiling water absorption rate is below 1.9%.

(10) Further, the cured product of the above resin composition has a tensile modulus at a temperature of from -60 ° C to -40 ° C of from 1 × 10 ⁹ Pa to 1 × 10 ¹⁰ Pa, and a tensile modulus at 80 ° C to 100 ° C It is preferably 1 × 10 ⁶ Pa to 2 × 10 ⁷ Pa.

(11) Further, the polyoxyalkylene polyamine of the above sensor cast product is preferably a polyoxypropylene diamine.

The resin composition of the present invention or the castable for a sensor can maintain the thermal shock resistance of the resin cured product while improving the moisture resistance, so that the sensing can be maintained for a long period of time even under a severe use environment. Excellent reliability of the device.

1‧‧‧Thermistor Sensor

2‧‧‧Temperature components

3‧‧‧ lead

4‧‧‧External leads

5‧‧‧protection box

6‧‧‧Resin Department

Fig. 1 is a schematic cross-sectional view showing a thermistor sensor according to an embodiment of the present invention.

Fig. 2 is a graph showing the relationship between the amine equivalent of the resin composition curing agent of the present invention and the shape retention time in the moisture resistance test.

Embodiments of the present invention are described in detail below.

The resin composition of the present invention is characterized by comprising an epoxy resin and a polyoxyalkylene polyamine.

The resin composition of the present invention will be described in detail below.

(1) Epoxy resin

Specific examples of the epoxy resin used in the present invention include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, and phenol novolac type epoxy resin. a glycidyl ether type epoxy resin such as a resin, a cresol novolac epoxy resin, a glycidyl ester type hexahydrophthalate glycidyl ester or a dimer acid glycidyl ester, a triglycidyl isocyanurate, A glycidylamine type epoxy resin such as tetraglycidyldiaminodiphenylmethane or a monovalent pentoxide, such as neopentyl glycol, trimethylolpropane, 1,6-hexanediol or 1,4-butanediol, or Alcohol ether type epoxy resin composed of polyvalent alcohol, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, epoxy resin having biphenyl skeleton, epoxy resin having naphthalene skeleton, and alicyclic ring Epoxy resin, etc.

Among them, an epoxy resin which is liquid at normal temperature is preferable, but even if it is a solid epoxy resin at normal temperature, it can be dissolved into a ring which is liquid at normal temperature. Use after oxygen resin. Further, these epoxy resins may be used singly or in combination of two or more.

(2) Polyoxyalkylene polyamines

In the present invention, a polyoxyalkylene polyamine having an amine equivalent of 225 g/eq or less is used as a curing agent. The polyoxyalkylene polyamine is a flexible amine, and the flexible portion in the molecule can alleviate thermal shock. Therefore, according to the present invention using a polyoxyalkylene polyamine, a cured product having excellent thermal shock resistance can be obtained. Further, by using a polyoxyalkylene polyamine, a resin composition having a low viscosity and a good activation period can be obtained, and workability such as casting can be improved.

The amine equivalent is the number of grams of amine containing 1 equivalent of active hydrogen, which is determined by dividing the number of active hydrogens by the molecular weight of the amine.

Specifically, the calculated total amine valence is substituted into the following formula according to the method for measuring the total amine valence of JIS 7237:1995.

(amine equivalent) = [1/{(full amine valence) x n}] x 56.11 x 1000

(Here, grade 1 amine n=2, grade 2 amine n=1)

By using a polyoxyalkylene polyamine having an amine equivalent of 225 g/eq or less, a cured resin having excellent thermal shock resistance and moisture resistance can be obtained. When the amine equivalent of the polyoxyalkylene polyamine exceeds 225 g/eq or more, the obtained resin cured product has low moisture resistance, and when used under high humidity conditions for a long period of time, sufficient shape retainability cannot be obtained. The polyoxyalkylene polyamine has an amine equivalent of more preferably 200 g/eq or less. Thereby, the thermal shock resistance and moisture resistance of the obtained cured resin body are further improved.

On the other hand, although the lower limit of the amine equivalent of the polyoxyalkylene polyamine is not particularly limited, it is preferably 100 g/eq or more, and more preferably 120 g/cm, in consideration of workability such as uniform dispersion of an epoxy resin or the like. Above eq.

The polyoxyalkylene polyamine used in the present invention may, for example, be a polyoxypropylene triamine, a polyoxypropylene diamine, a polyoxyethylene diamine, a polytetramethylene ether glycol/polypropylene glycol copolymer. A diamine, a polypropylene glycol/polyethylene glycol copolymer type diamine, or the like. Among these, a polyoxypropylene diamine is particularly preferable from the viewpoints of flexibility and moisture resistance.

The above polyoxyalkylene polyamines may be used singly or in combination of plural kinds. The amine equivalent weight when a plurality of polyoxyalkylene polyamines are used is expressed as the average amine equivalent of the polyoxyalkylene polyamine present per unit mass. For example, the compounding amount (mass) of the amine 1 having an amine equivalent of a ₁ g/eq and the amine 2 having an amine equivalent of a ₂ g/eq is m ₁ and m ₂ , respectively, and the average amine equivalent of the prepared resin composition It is calculated by the following calculation formula.

Average amine equivalent = (m ₁ + m ₂ ) / [(m ₁ / a ₁ ) + (m ₂ / a ₂ )]

In the present invention, the amine equivalent of the polyoxyalkylene polyamine is preferably in the range of 0.40 to 0.75 equivalents based on 1 equivalent of the epoxy equivalent of the epoxy resin. By setting the equivalent ratio within the above range, the thermal shock resistance and moisture resistance of the cured resin obtained are further improved. When the amine equivalent of the polyoxyalkylene polyamine exceeds 0.75 equivalent based on 1 equivalent of the epoxy equivalent of the epoxy resin, it is found that the thermal shock resistance tends to be lowered. On the other hand, when the amine equivalent of the polyoxyalkylene polyamine is less than 0.40 equivalent with respect to 1 equivalent of the epoxy equivalent of the epoxy resin, excellent heat shock resistance can be obtained. However, the resin cured product has high plasticity and may be dissolved in oil or the like.

(3) Filling agent

In the resin composition of the present invention, an inorganic filler is preferably added as a filler. The inorganic filler may, for example, be a stone, a calcium carbonate, a calcium and magnesium bicarbonate (Ca.Mg(CO ₃ ) ₂ ), alumina, aluminum hydroxide, magnesium hydroxide, clay, talc, mica or ash. Stone, boron nitride, tantalum nitride, etc. Among these inorganic fillers, alumina, boron nitride, tantalum nitride or the like having high thermal conductivity is preferable, and alumina is particularly preferable. As the alumina, a crystal form of any of α alumina, β alumina, and γ alumina can be used, but from the viewpoint of stability, α alumina is preferably used.

The average particle diameter of the inorganic filler is preferably from 1 to 100 μm, more preferably from 1 to 10 μm. In the present invention, a part of the inorganic filler may be alumina having a particle diameter of 1 μm or less (hereinafter referred to as "fine alumina"). In this case, the fine alumina acts as a sedimentation preventing agent for other inorganic fillers, and a castable in which the inorganic filler is uniformly dispersed can be obtained. The use ratio of the fine alumina used as the sedimentation inhibitor is preferably 0.1% by mass to 40% by mass based on the total amount of the inorganic filler (the total amount of the inorganic filler other than the fine alumina and the fine alumina). More preferably, it is 1% by mass to 30% by mass. The amount of the inorganic filler to be added is preferably 55% by mass or more, and more preferably 65% by mass or more based on the entire composition. When the addition amount of the inorganic filler is 55 mass% or more, the thermal conductivity reaches 0.5 W/m. Above K, the performance of the sensor is further improved. The upper limit of the amount of use of the inorganic filler is not particularly limited, but is preferably 80% by mass or more in consideration of workability in the pouring operation.

(4) Other additives

In the resin composition of the present invention, various other additives may be added as needed within the range not impairing the effects of the invention. The above additives may, for example, be a coloring agent, a flame retardant, an antifoaming agent, a coupling agent, a adhesion improving agent, an impact relaxing agent, a sedimentation preventing agent, a thickening agent, a diluent or the like.

(5) Modification method of resin composition

When the resin composition of the present invention is in a one-liquid type, an epoxy resin, a polyoxyalkylene polyamine, and a predetermined amount of a filler added as needed, and the above other additives may be mixed by using a stirrer or the like. Make modulation. Further, in the case of the two-liquid type, a predetermined amount of a filler and other additives are added to the epoxy resin as needed, and the main component is prepared by mixing. On the other hand, in the polyoxyalkylene polyamine, other curing agents and additives are added as needed, and mixed to prepare a curing agent. When a sensor or the like is manufactured, the above-mentioned main agent and a curing agent are mixed by a stirrer or the like, and used.

(6) Cured product of resin composition

The resin composition of the present invention containing an epoxy resin and a polyoxyalkylene polyamine can be used as a sensor for casting. The curing conditions are not particularly limited, but the curing temperature is preferably from 80 ° C to 150 ° C, and the curing time is preferably from 0.5 to 10 hours. Here, the boiling water absorption rate of the cured product of the resin composition is 1.9% or less. modulation. The boiling water absorption rate is a value indicating the water absorption rate after the moisture resistance test of the cured resin product by the method described later. By adjusting the boiling water absorption rate of the cured resin product to 1.9% or less, the shape retainability after long-term use under high humidity can be remarkably improved. Specifically, it has been confirmed that the cured resin body having a boiling water absorption of 1.9% or less remains in its original shape after being left in an environment of 85 ° C and a relative humidity of 85% for 4,000 hours. The boiling water absorption rate of the cured resin is preferably 1.7% or less, more preferably 1.6% or less.

Further, the cured product of the resin composition calculated by the method described later preferably has a tensile modulus at -60 ° C to -40 ° C of from 1 × 10 ⁹ Pa to 1 × 10 ¹⁰ Pa at 80 ° C to 100 ° C. The tensile modulus is preferably from 1 × 10 ⁶ Pa to 2 × 10 ⁷ Pa. By lowering the elastic modulus at -60 ° C to 40 ° C and the elastic modulus at 80 ° C to 100 ° C, the thermal shock resistance can be improved, and the adhesion to the protective case can be maintained even after long-term use in severe thermal cycling. .

(7) Manufacture of thermistor temperature sensor

The resin composition of the present invention is suitably used for casting between a temperature sensor element of a temperature sensor of a thermistor sensor or the like and a protective case. Hereinafter, a method of manufacturing the thermistor sensor according to an embodiment of the present invention will be described. As shown in Fig. 1, in the thermistor sensor 1 of the present embodiment, the temperature element 2, the wire 3 composed of a copper wire or the like connected to the temperature element 2, and the external wire 4 connected by the wire 3 (4a) The end of 4b) is inserted into the protective case 5. Here, the resin composition of the present invention is injected into the protective case 5 to be cured to form the resin portion 6.

Further, as the protective case, in addition to a metal case such as copper, a resin case such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or ABS resin can be used. When any one of the cases is used, the effects of the resin composition of the present invention and the castable for the sensor can be exerted. The external lead 4 is an insulated electric wire covered with an insulating cover 4b such as a soft vinyl chloride resin or a bridging polyethylene on the outer circumference of the conductor 4a. In the manufacture of the thermistor sensor 1, after the resin composition is injected into the protective case 5, the temperature element 2 to which the lead 3 and the external lead 4 are connected is inserted to cure the resin composition. Further, the temperature element 2 to which the lead wire 3 and the external lead 4 are connected may be inserted into the protective case 5, and then the resin composition may be injected and cured. The curing temperature of the resin composition is preferably from 80 ° C to 150 ° C, and the curing temperature is preferably from about 0.5 hours to 10 hours.

In the thermistor sensor 1, by using the resin composition of the present invention, the resin portion is not peeled off from the protective case or the like even under severe thermal cycling conditions, and long-term use under high humidity is also used. The shape can be maintained, so that a sensor with high reliability can be realized.

The invention is described in more detail below by way of examples, but the invention is not limited by these examples. In addition, in the case where there is no particular description in the examples, "%" and "part" indicate the mass% and the quality part.

(composition of resin composition)

(A) main agent

(A1) bisphenol A type epoxy resin: jER815, epoxy equivalent 184g/eq Mitsubishi Chemical Column Co., Ltd.

(A2) Polyoxyalkylene bisphenol A diglycidyl ether (polyoxyalkylene bisphenol A type epoxy resin), epoxy equivalent: 510 g/eq, manufactured by ADEKA Co., Ltd.

(B) curing agent

(B1) polyoxypropylene diamine: JEFFAMINE D-400, molecular weight: about 400, amine equivalent; 114 g / eq HUNTSMAN company

(B2) Polyoxypropylene diamine: JEFFAMINE D-2000, molecular weight: about 2000, amine equivalent: 500 g/eq, manufactured by HUNTSMAN

(B3) polytetramethylene ether glycol/polypropylene glycol copolymer type diamine: XTJ-542, molecular weight: about 1000, amine equivalent: 260 g/eq, manufactured by HUNTSMAN

(B4) Anhydride: methyltetrahydrophthalic anhydride: HN-2000, anhydride equivalent: 166 g/eq, manufactured by Hitachi Chemical Co., Ltd.

(B5) 2,4,6-tris(dimethylaminomethyl)phenol: Ancamine K-54 manufactured by Air Products Chemicals, Inc.

(Examples 1 to 9, Comparative Examples 1 to 3, Reference Example 1)

The epoxy resin, the coupling agent, the pigment, and the filler were mixed in a stirrer in the ratio (mass) shown in Table 1 and Table 2 to prepare a main component. The curing agents shown in Table 1 or Table 2 were mixed alone or in combination of two or more kinds, and then mixed with a main component in accordance with the ratio (mass) shown in Tables 1 and 2 to prepare a resin composition. The resin composition that will be obtained, Each of the models for preparing the test piece for evaluating the boiling water absorption rate, the moisture resistance, the tensile modulus, and the thermal shock resistance was injected in a mold for heating at 100 ° C for 5 hours. The boiling water absorption rate, moisture resistance, tensile modulus, and thermal shock resistance of the obtained test piece (cured product) were evaluated by the method described later, and the results are shown in Tables 1 and 2.

(Measurement of boiling water absorption rate)

The resin composition was poured into a mold, and heated at 100 ° C for 5 hours to be solidified to obtain a sample for boiling water absorption measurement of 45 mm φ and 3 mm thick. The sample was boiled in water at 100 ° C for 24 hours, taken out, dried at 40 ° C for 5 hours, and dried at 100 ° C for 5 hours, and the weight of the sample after boiling and after drying was measured. The boiling water absorption rate was calculated by the following formula.

(Boiling water absorption rate) = [{(weight of sample after boiling) - (weight of sample after drying)} / (weight of sample after drying)] x100

(Humidity resistance test: shape retention test)

The resin compositions of the examples and the comparative examples were injected into a mold, and heated at 100 ° C for 5 hours to be solidified, thereby preparing a sample for moisture resistance test of 45 mm φ and 3 mm thick. Each sample was placed in a constant temperature and humidity chamber at a temperature of 85 ° C and a relative humidity of 85%, and taken out every 500 hours to observe (visually) shape retention. The time at which the sample was eluted was found as the elution time, and the evaluation was performed.

(Measurement of tensile modulus)

The resin composition was poured into a mold, heated at 100 ° C for 5 hours, and solidified, and then cut into a width of 10 mm, a length of 50 mm, and a thickness of 2 mm to prepare a sample for measurement. The tensile modulus was measured in accordance with JIS K 0129:2005 using a DMA measuring device.

(thermal shock resistance test)

After defoaming the resin compositions of the examples and the comparative examples, 2 ml of each of the 4 mm φ copper boxes (capacity: 2.5 ml) into which the analog sensor was inserted was injected using a syringe needle. Then, the resin composition was cured by heating at 100 ° C for 5 hours to obtain a sample for evaluation. In addition, connect two 1.2mm φ analog wires to the analog sensor.

The sample was first immersed in liquid nitrogen for 1 minute, taken out, and then immersed in eucalyptus oil maintained at 130 ° C for 1 minute, and then taken out. Then, after standing at room temperature for 2 minutes, the sensor was simulated by hand to confirm the presence or absence of extraction. This step was used as one cycle, and the number of cycles that the analog sensor element was taken out when the analog sensor element was pulled out was measured for each sample and evaluated.

As shown in Table 1, in Example 1 and Comparative Example 2, a polyoxypropylene diamine having an amine equivalent of 114 g/eq and a polytetramethylene ether glycol/polypropylene glycol copolymer having an amine equivalent of 260 g/eq were used alone. The type diamine acts as a curing agent. Further, in Example 2, Example 3, Example 4, Comparative Example 1 and Comparative Example 3, a polyoxypropylene diamine having an amine equivalent of 114 g/eq and a polyoxypropylene binary having an amine equivalent of 500 g/eq were changed. The mixing ratio of the amines is used to change the amine equivalent.

As shown in Table 1, it was found that in Comparative Example 1 in which the amine equivalent was 248 g/eq, the number of cycles in which the analog sensor element was pulled out was 3, and the thermal shock resistance was able to be applied to a practical level. However, it was also confirmed that the boiling water absorption rate was as high as 2.0%, the shape retention time was 3,500 hours, and the shape retention under high humidity conditions was insufficient. Further, in Comparative Example 3 in which the amine equivalent of 298 g/eq was found, good thermal shock resistance was obtained, but the shape was also obtained. The shape retention time was shorter than Comparative Example 1. Further, in Comparative Example 2 in which an amine equivalent of 260 g/eadel polytetramethylene ether glycol/polypropylene glycol copolymer type diamine was used, it was confirmed that the thermal shock resistance was good, but it was high. The shape retention under humidity conditions is insufficient. Here, the boiling water absorption ratios of Comparative Examples 2 and 3 were 2.0% as in Comparative Example 1.

On the other hand, in Examples 1, 2, 3, and 4 in which the amine equivalents were 114, 148, 186, and 212 g/eq, the number of cycles until the sensor element was pulled out was found, in either case. All of them are 3 or more, and it is possible to maintain excellent thermal shock resistance and to greatly increase the shape retention time. Further, the boiling water absorption rates of Examples 1, 2, 3, and 4 were 1.3%, 1.4%, 1.6%, and 1.7%, respectively, and the cured product of the resin composition containing the epoxy resin and the polyoxyalkylene polyamine was boiled. The water absorption rate is 1.7% or less, and it is possible to simultaneously satisfy excellent thermal shock resistance and moisture resistance.

Fig. 2 shows the relationship between the amine equivalent of the cured resin and the shape retention time in the moisture resistance test. From Fig. 2, it was confirmed that the shape retention time increased as the amine equivalent was lowered. When the amine equivalent is 225 g/eq or less, the shape retention time sharply rises, and when the amine equivalent is 200 g/eq or less, the shape retention time increases more remarkably.

Further, as Reference Example 1, an epoxy resin (polyoxyalkylene bisphenol A type epoxy resin, epoxy equivalent: 510 g/eq) and an acid anhydride (methyltetrahydrophthalic anhydride, acid anhydride equivalent: 166 g/eq) and an acid anhydride were used. 2,4,6-tris(dimethylaminomethyl)phenol, a resin composition having an equivalent ratio (anhydride equivalent/epoxide equivalent) of 0.9 was prepared, and a cured resin was obtained under the same conditions as in the above examples. It was confirmed that the above-mentioned resin cured product had a boiling water absorption rate of 1.4% and a shape retention time of more than 8,000 hours, and had good moisture resistance. However, in the above Reference Example 1, the tensile modulus at 80 ° C to 100 ° C is as high as 28 × 10 ⁶ Pa, and the sensor element is in the thermal shock resistance test in the specified temperature range (-40 ° C to -150 ° C). The number of cycles that had passed before being pulled out was about 1/10 of that of the examples, and it was found that sufficient thermal shock resistance could not be obtained.

The polyoxyalkylene bisphenol A type epoxy resin is known as an epoxy resin having a very excellent thermal shock resistance. Although not shown in the table, when a polyoxyalkylene polyamine is used as a curing agent, a cured product having excellent thermal shock resistance and moisture resistance can be obtained. However, in Reference Example 1 using an acid anhydride as a curing agent, such a cured product was not obtained.

From the above results, the effect of the resin composition containing the epoxy resin and the polyoxyalkylene polyamine of the present invention can be confirmed.

As shown in Table 2, in Examples 2 and 5 to 9, a polyoxypropylene diamine having an amine equivalent of 114 g/eg and a polyoxypropylene diamine having an amine equivalent of 500 g/eq were mixed at a mass ratio of 70:30. Curing agent. Here, by changing the mixing ratio of the main agent and the curing agent, samples having different equivalence ratios were prepared. Compared with Example 2 in which the equivalent ratio (amine equivalent/epoxide equivalent) was 0.6, in Examples 7, 8, and 9 in which the equivalent ratio was increased, the number of cycles passed when the analog sensor element was pulled out was reduced, In Examples 5 and 6 in which the equivalent ratio was reduced, the number of cycles increased.

In Example 5, in which the equivalent ratio is 0.4, although excellent thermal shock resistance can be obtained, the cured resin has high plasticity and may be dissolved in oil or the like. Therefore, it is preferable that the equivalent ratio is 0.4 or more. On the other hand, to ensure adequate circulation It can be said that the equivalent ratio is preferably 0.75 or less.

Further, in Example 5, it was found that the boiling water absorption rate was 1.9%, and a sufficient shape retention time was obtained. Therefore, the boiling water absorption rate of the cured product of the resin composition containing the epoxy resin and the polyoxyalkylene polyamine was 1.9%. Hereinafter, excellent thermal shock resistance and moisture resistance can be simultaneously satisfied.

1‧‧‧Thermistor Sensor

2‧‧‧Temperature components

3‧‧‧ lead

4‧‧‧External leads

5‧‧‧protection box

6‧‧‧Resin Department

Claims (11)

A resin composition comprising a resin composition of an epoxy resin and a polyoxyalkylene polyamine, wherein the polyoxyalkylene polyamine has an amine equivalent of 225 g/eq or less. The resin composition according to claim 1, wherein the amine equivalent is 200 g/eq or less. The resin composition according to claim 1 or 2, wherein the amine equivalent of the polyoxyalkylene polyamine is in the range of 0.40 to 0.75 equivalents with respect to 1 equivalent of the epoxy group of the epoxy resin. Inside. The resin composition according to claim 1 or 2, wherein the polyoxyalkylene polyamine is a polyoxypropylene diamine. The resin composition according to claim 1 or 2, further comprising an inorganic filler. The resin composition according to claim 5, wherein the inorganic filler contains at least one selected from the group consisting of alumina, boron nitride, and tantalum nitride. The resin composition according to claim 1 or 2, wherein the resin composition can be used for pouring of a sensor. A temperature sensor having a temperature sensor element, a box enclosing the temperature sensor element, and a casting between the temperature sensor and the box The resin composition as described in any one of claims 1 to 7. A castable for a sensor, which is a caster for a sensor comprising a resin composition comprising an epoxy resin and a polyoxyalkylene polyamine, wherein the cured product of the resin composition has a boiling water absorption of 1.9% or less. . The casting material for a sensor according to claim 9, wherein the cured product of the resin composition has a tensile modulus of from 1 to 10 ⁹ Pa to 1 × 10 ¹⁰ Pa at -60 ° C to -40 ° C. The tensile modulus at 80 ° C to 100 ° C is 1 × 10 ⁶ Pa to 2 × 10 ⁷ Pa. The sensor casting according to claim 9 or 10, wherein the polyoxyalkylene polyamine is a polyoxypropylene diamine.