JP2018065977A - Thermally conductive composition and thermally conductive member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally conductive composition which has high flowability with respect to a blend ratio of a thermally conductive filler and is excellent in workability, and to provide a thermally conductive member being a cured product of the same.SOLUTION: A thermally conductive composition which contains a reactive curable liquid resin, a non-reactive liquid resin and a thermally conductive filler, and where the reactive curable liquid resin is cured to form a polymer matrix, and the thermally conductive composition each contains 20-80 mass% of the reactive curable liquid resin and 20-65 mass% of aliphatic monocarboxylic acid ester of aliphatic polyhydric alcohol being the non-reactive liquid resin in 100 mass% of the whole liquid resin and has viscosity at 25°C of 10-1,000 Pa s.SELECTED DRAWING: None

Description

  The present invention relates to a heat conductive composition that is interposed between a heat generator and a heat radiator and transmits heat generated by the heat generator to the heat radiator and a heat conductive member that is a cured product thereof.

  As a heat conductive material that is interposed between the heat generating body and the heat radiating body and transmits heat generated by the heat generating body to the heat radiating body, heat conductive grease, a heat conductive sheet previously formed into a sheet shape, or fluid Thermally conductive compositions are known. While the heat conductive sheet is used by being sandwiched between the heat generating body and the heat radiating body, the heat conductive grease or the heat conductive composition can be used by being applied to the gap between the heat generating body and the heat radiating body. Therefore, when it cannot move in the state where the heat generating body and the heat radiating body are fixed, heat conductive grease or a heat conductive composition can be suitably used. Although heat conductive grease has the simplicity that it should just apply | coat between a heat generating body and a heat radiator, it is difficult to apply | coat when a clearance gap is narrow according to the grease-like property. On the other hand, since a heat conductive composition is liquid, there exists an advantage that application | coating is easy even when a clearance gap is narrow.

  Like the other heat conductive materials, the heat conductivity of the heat conductive composition largely depends on the blending amount of the heat conductive filler, and preferably contains a large amount of the heat conductive filler. However, when the blending amount of the heat conductive filler is increased, there is a problem that the viscosity of the heat conductive composition increases and it is difficult to enter the gap between the heat generator and the heat radiator. Further, in the case of producing a heat conductive sheet by curing the heat conductive composition into a sheet shape, there arises a problem that workability to the sheet is impaired when the viscosity is high. Therefore, there is a limit to increasing the blending amount of the heat conductive filler in the liquid heat conductive composition.

  As a prior art for solving the problems regarding the blending amount and viscosity of the heat conductive filler, for example, Japanese Patent Laid-Open No. 2001-348488 (Patent Document 1) includes three kinds of heat conductive fillers having different particle sizes. A technique of blending at a ratio of is disclosed. JP-A-4-328163 (Patent Document 2) provides a predetermined processability by blending a low polymerization degree organopolysiloxane and a spherical aluminum oxide into a high polymerization degree organopolysiloxane. However, a technique for highly filling a thermally conductive filler is disclosed. Alternatively, Japanese Patent Application Laid-Open No. 2008-031405 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2008-056761 (Patent Document 4) disclose a technique for highly filling a heat conductive filler by using a specific silane compound. It is disclosed.

JP 2001-348488 A JP-A-4-328163 JP 2008-031405 A JP 2008-056761 A

  However, in the techniques described in Japanese Patent Laid-Open No. 2001-348488 (Patent Document 1) and Japanese Patent Laid-Open No. 4-328163 (Patent Document 2), a heat conductive filler having a predetermined size and shape is used. Other than these thermally conductive fillers cannot be used. In addition, in the technique described in Japanese Patent Application Laid-Open No. 2008-031405 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2008-056761 (Patent Document 4), a specific silane compound is used, and it is desired to avoid a silicone-based material. In some cases it was not available. Therefore, there is a need for a thermally conductive composition having no such concerns and high fluidity.

  Accordingly, an object of the present invention is to obtain a heat conductive composition having high fluidity and excellent workability with respect to the blending ratio of the heat conductive filler. Moreover, it aims at providing the heat conductive member obtained by hardening | curing this heat conductive composition.

The thermally conductive composition and the thermally conductive member of the present invention that achieve the above object are configured as follows.
A heat conductive composition comprising a reaction curable liquid resin, a non-reactive liquid resin, and a heat conductive filler, wherein the reaction curable liquid resin is cured to form a polymer matrix. Of the 100% by mass of the total resin, 20 to 80% by mass of the reactive curable liquid resin and 20 to 65% by mass of an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol that is a non-reactive liquid resin, 25 It is a thermally conductive composition having a viscosity at 10 ° C. of 10 to 1000 Pa · s.

Since it is a heat conductive composition that includes a reaction curable liquid resin, a non-reactive liquid resin, and a heat conductive filler, and the reaction curable liquid resin can be cured to form a polymer matrix, Therefore, it is possible to obtain a thermally conductive member having a formability by reactive curing after application to a desired location.
Of 100% by mass of the entire liquid resin, 20 to 80% by mass of the reactive curable liquid resin and 20 to 65% by mass of an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol that is a non-reactive liquid resin, respectively. Therefore, it can be set as the heat conductive composition of a low viscosity with respect to the mixture ratio of a heat conductive filler.

  By adding an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol, the heat conductive filler can be highly filled while keeping the viscosity low. Dispersants and silane coupling agents are known as additives that can obtain this type of effect. However, in general, a dispersant can increase the dispersibility of the thermally conductive filler with a relatively small amount of addition, but does not necessarily have a sufficient effect in terms of increasing the fillability. Moreover, even if a dispersing agent is added, the effect which makes the hardened | cured material of a heat conductive composition soft is hardly acquired.

About a silane coupling agent, although a filling property can be improved a little by processing beforehand with respect to a heat conductive filler, this effect is not necessarily high. Further, by adding a silane coupling agent to the heat conductive composition by a so-called integral blend method, the filling property of the heat conductive filler can be improved to some extent. Due to volatilization and reactivity, the viscosity may increase over time, and there is a concern that the storage stability will deteriorate. Although this invention can also use a silane coupling agent and a dispersing agent together, even if it is a case where these are not included, a fillability can be improved.
And since the heat conductive composition has a viscosity of 10 to 1000 Pa · s at 25 ° C., it has fluidity, and it is possible to apply the heat conductive composition to the gap between the heat generator and the heat radiator. it can.

The aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol includes an aliphatic polyhydric alcohol having 3 or more hydroxyl groups in a hydrocarbon having 5 to 12 carbon atoms and a carboxyl group in a hydrocarbon having 5 to 12 carbon atoms. It can be set as the heat conductive composition which is ester with the aliphatic monocarboxylic acid provided with one.
About aliphatic monocarboxylic acid esters of aliphatic polyhydric alcohols, aliphatic polyhydric alcohols having 3 or more hydroxyl groups in hydrocarbons having 5 to 12 carbon atoms, and carboxyl groups in hydrocarbons having 5 to 12 carbon atoms Since it is an ester with one aliphatic monocarboxylic acid provided, it has good affinity with the polymer matrix, hardly causes bleeding from the cured product after curing the heat conductive composition, and has flexibility. Moreover, the viscosity of a heat conductive composition can be made low.

It can be set as the heat conductive composition whose reaction curable liquid resin is a nonpolar hydrocarbon polymer which has an allyl group at the terminal.
Low-viscosity heat conductive composition using a reaction curable liquid resin as a nonpolar hydrocarbon polymer having an allyl group at the end, mixed with an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol having polarity You can get things. Moreover, since it has an allyl group at the terminal, it can be combined with a predetermined curing agent to obtain a thermally conductive composition that cures under predetermined conditions.

  In addition, in electronic devices, if silicone materials are used, problems such as contact failure due to low molecular siloxane may occur, but by using nonpolar hydrocarbon polymers that are non-silicone materials, A heat conductive composition free from such concerns can be obtained.

It can be set as the heat conductive composition which contains 300-1700 mass parts of heat conductive fillers with respect to 100 mass parts of liquid resin.
Since the heat conductive composition contains 300 to 1700 parts by mass of the heat conductive filler with respect to 100 parts by mass of the liquid resin, the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol is mutually added to the heat conductive filler. It acts and acts like a dispersant, and the viscosity of the heat conductive composition can be kept low.

  A heat conductive member comprising a polymer matrix, a non-reactive liquid resin, and a heat conductive filler, wherein the non-reactive liquid resin is an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol. Of the total of 100% by mass of the polymer matrix and the non-reactive liquid resin, 20 to 80% by mass of the polymer matrix and 20 to 65% by mass of aliphatic monocarboxylic acid ester of aliphatic polyhydric alcohol, respectively. It can be set as a heat conductive member.

  A heat conductive member including a polymer matrix, a non-reactive liquid resin, and a heat conductive filler, wherein the non-reactive liquid resin includes an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol. The heat conduction containing 20 to 80% by mass of the polymer matrix and 20 to 65% by mass of the aliphatic monocarboxylic acid ester of aliphatic polyhydric alcohol out of the total 100% by mass of the polymer matrix and the non-reactive liquid resin. Since it was made into the property member, the viscosity can be lowered when the heat conductive composition is subjected to the curing reaction.

The hardness of the heat conductive member can be 0 to 90 in E hardness.
Because it is a thermally conductive member with a hardness of 0 to 90 in E hardness, sufficient flexibility is ensured along the shape of the heating element and heat dissipation element, and adhesion with the heating element and heat dissipation element is sufficiently secured. can do. Further, even if there is an impact or vibration on the heat radiating body, it can be buffered to reduce the influence on the substrate, and the heating element can be suitably protected.

The aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol includes an aliphatic polyhydric alcohol having 3 or more hydroxyl groups in a hydrocarbon having 5 to 12 carbon atoms and a carboxyl group in a hydrocarbon having 5 to 12 carbon atoms. It can be set as the heat conductive member which is ester with the aliphatic monocarboxylic acid provided with one.
About aliphatic monocarboxylic acid esters of aliphatic polyhydric alcohols, aliphatic polyhydric alcohols having 3 or more hydroxyl groups in hydrocarbons having 5 to 12 carbon atoms, and carboxyl groups in hydrocarbons having 5 to 12 carbon atoms Since it is an ester with one aliphatic monocarboxylic acid provided, it has good affinity with the polymer matrix, hardly bleeds from the heat conductive member, and has flexibility. Moreover, the viscosity of the heat conductive composition before hardening can be made low.

It can be set as the heat conductive member whose polymer matrix is nonpolar hydrocarbon polymer.
Since the polymer matrix is a non-polar hydrocarbon polymer, there is no possibility of problems such as contact failure due to low molecular siloxane as in the case of using a silicone material.

It can be set as the heat conductive member which contains 300-1700 mass parts of heat conductive fillers with respect to a total of 100 mass parts of a molecular matrix and non-reactive liquid resin.
Since it was set as the heat conductive member which contains 300-1700 mass parts of heat conductive fillers with respect to a total of 100 mass parts of a molecular matrix and non-reactive liquid resin, it can be set as a heat conductive member with high heat conductivity.

According to the heat conductive composition of the present invention, it is possible to highly fill the heat conductive filler while having a low viscosity.
Moreover, according to the heat conductive member of this invention, it has predetermined | prescribed hardness and softness, and heat conductivity is high.

  The present invention will be described with reference to embodiments. The heat conductive composition shown in the present embodiment includes a reaction curable liquid resin, a non-reactive liquid resin, and a heat conductive filler. Details of these components are as follows.

The liquid component in the heat conductive composition includes a reactive curable liquid resin and a non-reactive liquid resin.
A reactive curable liquid resin is a liquid component that forms a polymer matrix by a curing reaction. A reactive curable liquid resin that cures itself when heated or irradiated with light, or a separate curing material is added. It contains a reactive curable liquid resin that cures. Further, when the two components are polymerized by mixing the main agent and the curing agent, both the main agent and the curing agent are reaction-curable liquid resins.

  Examples of such a reaction curable liquid resin include an addition reaction type liquid resin, a condensation reaction type liquid resin, and the like, and an addition reaction type liquid resin is particularly preferable. This is because the addition reaction type liquid resin has a small cure shrinkage. More specifically, when cured in a state of being sandwiched between the heating element and the radiator, if the curing shrinkage is large, a gap may be formed between the heating element or the radiator. In the case of a liquid resin, there is little inconvenience that a gap is generated because the curing shrinkage is small.

  Examples of addition reaction type liquid resins include urethane monomers and oligomers, acrylate monomers and oligomers, epoxy monomers and oligomers, α-olefins such as polyisobutylene having an allyl group at the end, and other polar and nonpolar hydrocarbons. Examples thereof include polymers and organopolysiloxanes. Among these, it is preferable to use organopolysiloxane for applications in which flexibility is high and easy filling of the heat conductive filler is desired. Moreover, it is preferable to use a hydrocarbon-based resin for applications in which the problem of low molecular siloxane is concerned. When polyisobutylene, which is a nonpolar hydrocarbon polymer and has an allyl group at the end, is used, the cured product of the thermally conductive composition may be a thermally conductive member having a predetermined strength while being flexible. It is preferable in that it can be performed. The reactive curable liquid resins mentioned here may be used alone or in combination.

  The viscosity of the reaction curable liquid resin at 25 ° C. is preferably about 0.05 Pa · s to 100 Pa · s. A liquid resin having a viscosity of less than 0.05 Pa · s has a low molecular weight, and it is difficult to increase the molecular weight even after being cured, so that the thermally conductive member after curing may become brittle. On the other hand, if the viscosity exceeds 100 Pa · s, the viscosity of the thermally conductive composition is likely to increase, and even when combined with an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol described later, the thermally conductive filler There is a possibility that the blending amount of the resin is reduced, and the thermal conductivity is lowered.

  Further, by including an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol, the viscosity reducing effect is great when combined with a liquid resin having a relatively high viscosity such that the viscosity at 25 ° C. is 10 Pa · s or more. If a liquid resin having a viscosity of 10 Pa · s or more can be used, the molecular weight is high to some extent, which is preferable in that the physical properties after curing can be improved. Examples of such a reaction curable liquid resin include allyl-terminated polyisobutylene and α-olefin.

  The reaction-curable liquid resin is preferably 20 to 80% by mass in 100% by mass of the entire liquid resin. If the ratio of the reaction curable liquid resin is less than 20% by mass, desired physical properties such as hardness and flexibility of the cured product may not be obtained. On the other hand, if it exceeds 80% by mass, the proportion of the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol becomes relatively small, and the heat conductive filler cannot be highly filled, and the viscosity of the heat conductive composition is reduced. There is a possibility that it cannot be sufficiently reduced.

The non-reactive liquid resin is a liquid component that is not cured by heating or light irradiation. In other words, even if the thermally conductive composition is cured to form a thermally conductive member, it is a component that does not form a polymer matrix in the thermally conductive member.
Examples of such non-reactive liquid resins include liquid resins that have the same type of skeleton as the reaction-curable liquid resin but do not have a reactive group, and those that do not have such a skeleton and are mixed with the reaction-curable liquid resin. Can do. Examples of those having the same type of skeleton as the reaction curable liquid resin include hydrocarbon oils such as paraffin oil, poly α olefin, and process oil, acrylic oil, silicone oil, and the like. Moreover, ester oils such as aliphatic monocarboxylic acid esters of aliphatic polyhydric alcohols described later, polybutene oils, and the like can be exemplified as those that do not have the same type of skeleton as the reaction-curable liquid resin.

  In the present invention, an aliphatic monocarboxylic acid aliphatic monocarboxylic acid ester is included as an essential component among non-reactive liquid resins. The aliphatic monocarboxylic acid aliphatic monocarboxylic acid ester is an aliphatic polycarboxylic alcohol and an aliphatic monocarboxylic acid ester-bonded, and constitutes an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol. The aliphatic polyhydric alcohol and the aliphatic monocarboxylic acid are as follows.

  First, the aliphatic polyhydric alcohol is preferably a compound having 3 or more hydroxyl groups in a hydrocarbon having 5 to 12 carbon atoms. For example, trimethylolpropane, pentaerythritol, xylitol, boremitol and the like can be exemplified. When the number of carbon atoms is less than 5, the affinity with the polymer matrix may be impaired, and there is a concern about bleeding from the cured product. On the other hand, when the number of carbon atoms exceeds 12, there is a concern that the viscosity of the ester increases and the effect of lowering the viscosity of the thermally conductive composition is reduced.

  All the hydroxyl groups contained in the aliphatic polyhydric alcohol are preferably esterified. If the hydroxyl group remains, the hydrophilicity increases, so the compatibility with the reaction curable liquid resin may be impaired, and the moisture resistance of the cured product may be impaired. In addition, some reactive curable liquid resins may react with hydroxyl groups. The aliphatic polyhydric alcohol is preferably saturated aliphatic. This is because the presence of an unsaturated group may also react with some of the reaction-curable liquid resin and the weather resistance may be impaired.

Next, the aliphatic monocarboxylic acid is preferably a compound having one carboxyl group in a hydrocarbon having 5 to 12 carbon atoms. For example, medium chain fatty acids such as pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, ethylhexanoic acid, nonanoic acid and decanoic acid are suitable. When the number of carbon atoms is less than 5, there is a concern that the effect of reducing the viscosity of the heat conductive composition may be reduced, and the flexibility of the cured product may be impaired. On the other hand, when the number of carbon atoms exceeds 12, there is a concern that the viscosity of the ester increases and the effect of lowering the viscosity of the thermally conductive composition is reduced.
The aliphatic monocarboxylic acid is preferably saturated aliphatic. This is because the presence of the unsaturated group may react with a part of the reaction-curable liquid resin and the weather resistance may be impaired.

  The viscosity of the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol is preferably 0.01 to 10 Pa · s at 25 ° C. Examples of the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol include trimethylolpropane or pentaerythritol and an ester of hexanoic acid, heptanoic acid, octanoic acid or ethylhexanoic acid. These have a relatively low viscosity and are particularly excellent in the effect of reducing the viscosity of the thermally conductive composition.

  The viscosity of the non-reactive liquid resin other than the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol is preferably 0.05 Pa · s to 10 Pa · s at 25 ° C. A liquid resin having a viscosity of less than 0.05 Pa · s has a low molecular weight and remains reactive after curing, so that it may volatilize during long-term use, and heat conductivity after curing. The member may become brittle. On the other hand, if the viscosity exceeds 100 Pa · s, the viscosity of the heat conductive composition is likely to increase, and the amount of the heat conductive filler is small even if an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol is included. Therefore, there is a possibility that the thermal conductivity is lowered.

  The aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol is preferably 20 to 65% by mass in 100% by mass of the whole liquid resin. If the content of the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol is less than 20% by mass, the effect of reducing the viscosity may be reduced. The rate may be low. On the other hand, if it exceeds 65% by mass, the content of the reaction-curable liquid resin is relatively reduced, and the physical properties of the cured product may be reduced.

  The non-reactive liquid resin other than the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol can be added as occupying 0 to 40% by mass in 100% by mass of the entire liquid resin. That is, non-reactive liquid resins other than aliphatic monocarboxylic acid esters of aliphatic polyhydric alcohols need not be added, while the upper limit is 40% by mass. When the amount exceeds 40% by mass, the proportion of either one or both of the reaction curable liquid resin and the aliphatic monocarboxylic acid aliphatic monocarboxylic acid ester is relatively reduced. There is a risk of causing problems.

  A thermally conductive filler is added to impart thermal conductivity. Examples of the thermally conductive filler include fine powder made of metal, carbon, metal oxide, metal nitride, metal carbide, metal hydroxide, carbon fiber, and the like. Examples of the metal include copper and aluminum. Examples of the carbon include pitch-based carbon fibers, PAN-based carbon fibers, fibers obtained by carbonizing resin fibers, fibers obtained by graphitizing resin fibers, and graphite powder. When voltage resistance is required for the thermally conductive member, it is preferable to use a thermally conductive filler other than metal or carbon.

  Examples of the metal oxide include aluminum oxide, magnesium oxide, zinc oxide, iron oxide, and quartz. Examples of the metal nitride include boron nitride and aluminum nitride. In addition, examples of the metal carbide include silicon carbide, and examples of the metal hydroxide include aluminum hydroxide. Such a heat conductive filler can be oriented in a certain direction in the liquid resin, and is preferable in terms of increasing the heat conductivity in the oriented direction.

  The shape of the heat conductive filler may be spherical or non-spherical, but preferably includes a plurality of spherical particles having different average particle diameters. This is because the viscosity of the thermally conductive composition can be reduced by combining spherical particles having different average particle diameters.

  The content of the heat conductive filler is preferably 300 to 1700 parts by mass, and more preferably 300 to 800 parts by mass with respect to 100 parts by mass of the liquid resin. When the content of the heat conductive filler is 300 parts by mass or more with respect to 100 parts by mass of the liquid resin, a remarkable effect of viscosity reduction is obtained. If the content is 800 parts by mass, the viscosity at 25 ° C. is 500 Pa · s or less. If the amount is up to 1700 parts by mass, the greater the blending amount, the higher the thermal conductivity, and if it exceeds 1700 parts by mass, the viscosity becomes too high. The reason why 300 to 1700 parts by mass of the thermally conductive filler can be contained with respect to 100 parts by mass of the liquid resin is that the aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol interacts with the thermally conductive filler. This is because the action like a dispersant is considered to occur, and the viscosity of the heat conductive composition at 25 ° C. can be made 10 to 1000 Pa · s.

In addition to the liquid resin and the heat conductive filler, the components in the heat conductive composition further include various additives for the purpose of improving various properties such as processability, productivity, weather resistance, and heat resistance. be able to. Examples thereof include various functional improvers such as a reinforcing material, a colorant, a heat resistance improver, a surfactant, a dispersant, a coupling agent, a flame retardant, a catalyst, a curing retarder, and a deterioration inhibitor.
And a heat conductive composition can be obtained by mixing each component, such as liquid resin, a heat conductive filler, and a required additive.

Since the thermally conductive composition is highly filled with a thermally conductive filler to enhance thermal conductivity, it appears to be a highly viscous paste-like property. It is preferable to have a viscosity that facilitates application and sheeting, and more specifically, it is preferably 10 to 1000 Pa · s at 25 ° C. If the viscosity of the heat conductive composition is less than 10 Pa · s, the amount of heat conductive filler added is relatively small, and the heat conductivity of the heat conductive composition may be insufficient. On the other hand, when it exceeds 1000 Pa · s, there is a possibility that the operation of coating and sheet forming becomes difficult.
In addition, the said viscosity shows the viscosity measured at the rotational speed of 10 rpm using the rotor of spindle SC4-14 with the viscometer (BROOKFIELD rotational viscometer DV-E).

  The thermally conductive composition is cured according to the type of reaction curable liquid resin, that is, a polymer matrix is formed by a predetermined means such as heating, light irradiation, ultraviolet irradiation, etc. It becomes.

  The hardness of the heat conductive member is preferably 0 to 90, preferably 0 to 50, as measured by a Japanese Industrial Standard JIS K 6253 type E hardness tester (hereinafter referred to as “E hardness”). It is more preferable. When the E hardness exceeds 90, sufficient follow-up to the shape of the heating element or the heat radiating body is not obtained, the adhesion between the heating element or the heat radiating body and the heat conductive member is lowered, and the heat conductivity is also lowered. There is a risk. When the E hardness is 90 or less, it is possible to sufficiently ensure the flexibility of following along the shape of the heating element and the heat dissipation body and the adhesion with the heating element and the heat dissipation element. If the E hardness is 50 or less, for example, even if there is an impact or vibration on the radiator, the thermally conductive member cushions to reduce the influence on the substrate, thereby suitably protecting these adherends. can do.

  When the E hardness is 0 or close to 0 and expressed using another index, the immiscible consistency measured using a ¼ cone according to JIS K 2220 (also simply referred to as “consistency”) is 100 or less. It is preferable that it is 90 or less. If the consistency exceeds 100, there is a possibility that pump-out will occur after long-term use due to insufficient curability.

  In Experimental Example 1 to Experimental Example 3 shown below, the components shown in Tables 1 to 3 are mixed in the respective compounding amounts to prepare the thermally conductive compositions of Samples 1 to 20, and this thermally conductive composition. Was cured to prepare thermal conductive members of Samples 1-20. Although it demonstrates in detail below, the compounding quantity of each component in a table | surface is shown by a mass part. The viscosity is the result of measurement using a viscometer (BROOKFIELD rotational viscometer DV-E) under the conditions of a rotational speed of 10 rpm and 25 ° C. using a rotor of spindle SC4-14.

Experimental Example 1: Influence of various non-reactive liquid resins on allyl-terminated polyisobutylene Thermally conductive compositions of samples 1 to 4 in which the kind of non-reactive liquid resin mixed with allyl-terminated polyisobutylene as a reaction-curable liquid resin was changed The heat conductive member of Samples 1-4 which is a thing and its hardened | cured material was produced.

Sample 1:
As reaction-curable liquid resin, 44 parts by mass of allyl-terminated polyisobutylene, and as non-reactive liquid resin, 56 parts by mass of trimethylhexanoic acid trimethylolpropane, which is an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol, are thermally conductive. As a filler, aluminum hydroxide (amorphous and having an average particle diameter of 1.2 μm and amorphous and having an average particle diameter of 10 μm and an amorphous and having an average particle diameter of 50 μm in a weight ratio of 3: 5: 8) The heat conductive composition shown as the sample 1 of Table 1 was produced by mixing 320 parts by mass of the mixed mixture) and 100 parts by mass of aluminum oxide (spherical, average particle size 20 μm). Further, the thermally conductive composition of Sample 1 was heat-cured at 100 ° C. for 1 hour to prepare a thermally conductive member of Sample 1 that was a cured product. The allyl-terminated polyisobutylene as the reaction-curable liquid resin contains 1 part by weight of hydrogen organopolysiloxane as the curing agent with respect to 10 parts by weight of the allyl-terminated polyisobutylene as the main agent, and the total is 44 weights. Part.
The viscosity of the main component of allyl-terminated polyisobutylene was 50 mPa · s, and the viscosity of trimethylolpropane triethylhexanoate was 0.1 Pa · s.

Sample 2:
The non-reactive liquid resin used in Sample 1 was changed to tetraethylhexanoic acid pentaerythritol (viscosity 0.07 Pa · s) which is an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol shown in Table 1, and otherwise. In the same manner as Sample 1, a thermally conductive composition of Sample 2 and a thermally conductive member of Sample 2 as a cured product thereof were produced.

Sample 3:
The non-reactive liquid resin used in sample 1 was changed to the process oil shown in Table 1 (paraffinic, viscosity 0.08 Pa · s), and the heat conductive composition of sample 3 was otherwise the same as sample 1. And the heat conductive member of the sample 3 which is the hardened | cured material was produced.

Sample 4:
The non-reactive liquid resin used in Sample 1 was changed to the side chain ester oil (viscosity 0.1 Pa · s) shown in Table 1, and the heat conductive composition of Sample 4 was otherwise the same as Sample 1. And a thermally conductive member of Sample 4 which is a cured product thereof.

Analysis of experimental results 1:
The effect of the type of non-reactive liquid resin mixed with allyl-terminated polyisobutylene as a reactive curable liquid resin was investigated.
Based on sample 3 using process oil as a non-reactive liquid resin, the viscosity of each sample was compared for sample 1, sample 2 and sample 4 using non-reactive liquid resin other than process oil. Sample 1 using trimethylol hexane hexanoate had a ratio of 0.55 to that of sample 3. Sample 2 using tetraethylhexanoate pentaerythritol had a ratio of 0.71 to that of sample 3. Sample 4 using the side chain ester oil was 0.90 in comparison with sample 3. From these results, it was found that the viscosity of pentaerythritol tetraethylhexanoate can be considerably reduced, and the viscosity of the side chain ester oil is only slightly reduced.

All of the above samples 1 to 4 use allyl-terminated polyisobutylene as the reaction curable liquid resin. From these results, the non-reactive liquid resin to be mixed with the reaction curable liquid resin has a process oil. If the ester oil is used, the viscosity reduction effect can be expected. It has been found that the viscosity can be greatly reduced.
Moreover, E hardness of the samples 1-4 is E18-E24, and any heat conductive member was a heat conductive member which has suitable hardness.

Experimental Example 2: Influence of various reaction-curable liquid resins other than allyl-terminated polyisobutylene The heat conductive composition of Samples 5 to 10 and the heat of Samples 5 to 10 which are cured products by changing the type of the reaction-curable liquid resin A conductive member was produced. The components and blending amounts are shown in Table 2. In addition, the same thing as the component name shown in Table 1 among the component names shown in Table 2 shows the same content as Table 1.

Samples 5 and 6:
Allyl group-containing organopolysiloxane (1.0 Pa · s) was used as the reaction-curable liquid resin. For the allyl group-containing organopolysiloxane as the main agent, hydrogen organopolysiloxane as the curing agent was used and mixed in a ratio of main agent: curing agent = 10: 1. Moreover, the heat conductive composition of the obtained samples 5 and 6 was hardened on the conditions of 120 degreeC and 1 hour, and the heat conductive members of samples 5 and 6 were produced.

Samples 7 and 8:
An ester acrylic oligomer (9.0 Pa · s) was used as the reaction curable liquid resin. Azobisisobutyronitrile was used as a reaction initiator for the ester acrylic oligomer as the main agent, and this was mixed in a ratio of main agent: reaction initiator = 100: 1. Moreover, the heat conductive composition of the obtained samples 7 and 8 was hardened | cured on 100 degreeC and the conditions for 1 hour, and produced the heat conductive members of the samples 7 and 8.

Samples 9, 10:
Bisphenol A epoxy resin (2.3 Pa · s) was used as the reaction curable liquid resin. An aliphatic polyamine as a curing agent was used for the bisphenol A epoxy resin as the main agent, and this was mixed at a ratio of main agent: curing agent = 10: 1. The thermally conductive compositions of Samples 9 and 10 obtained here were cured under the conditions of 120 ° C. and 1 hour to prepare Samples 9 and 10 thermally conductive members.

Analysis of experimental results 2:
The viscosity reduction effect by the kind of reaction curable liquid resin was examined.
Allyl group-containing polyorganosiloxane, ester acrylic oligomer, and bisphenol A epoxy resin were used as the reaction curable liquid resin, and a sample in which triethylhexanoic acid trimethylolpropane was added as a non-reactive resin and process oil were added. The viscosity of the samples was compared.

As a result, all the samples to which trimethylolpropane triethylhexanoate was added had a lower viscosity than the samples to which the process oil was added. That is, the sample 5 using the allyl group-containing polyorganosiloxane has a viscosity ratio of 0.36 with the sample 6 and the sample 7 using the ester-linked acrylate oligomer has a viscosity ratio of 0.69 with the sample 8. . Further, the viscosity of the sample 9 using the bisphenol A epoxy resin was 165 Pa · s, and the sample 10 using the process oil did not show fluidity, but showed good fluidity.
From these results, it was found that the aliphatic monocarboxylic acid ester of aliphatic polyhydric alcohol can be expected to have a viscosity reducing effect on various reaction-curable liquid resins.
Samples 5 and 6 have an E hardness of about E15, samples 7 and 8 have an E hardness of about E70, samples 9 and 10 have an E hardness of about E90, and the samples 5, 7, and 9 are preferably thermally conductive members. It was a heat conductive member having a high hardness.

Experimental Example 3: Effect of change in blending amount of each component With the thermally conductive composition of Samples 11 to 20 and its cured product by changing the blending amount of the reactive curable liquid resin, the non-reactive liquid resin, and the thermally conductive filler. The heat conductive members of certain samples 11 to 20 were produced. The components and blending amounts are shown in Tables 3 and 4. Of the component names shown in Tables 3 and 4, the same component names as shown in Tables 1 and 2 have the same contents as those in Tables 1 and 2. The polyalphaolefins in Tables 3 and 4 were those having a viscosity of 1.9 Pa · s.

Analysis of experimental results 3:
The effect of reducing the viscosity due to the difference in the amount of each component was examined.
When the viscosity ratios of Samples 11 to 16 were viewed, all were in the range of 0.70 to 0.77, and it was found that an excellent viscosity reducing effect was exhibited at least in the range of the studied blending amounts. Moreover, although the heat conductive composition which shows fluidity | liquidity was not obtained for the sample 18 and the sample 20 which used process oil, all the samples which used the triethyl hexanoic acid trimethylol propane have fluidity | liquidity. It was. Moreover, even if it used non-reactive liquid resin like the samples 13 and 15, it turned out that it has a viscosity reduction effect by containing a triethylhexanoic acid trimethylol propane.

From these results, it was found that the viscosity reduction effect can be expected when the blending amount of the aliphatic monocarboxylic acid ester of the aliphatic polyhydric alcohol is 20 to 65 parts by mass with respect to 100 parts by mass of the liquid resin. Moreover, it turned out that a viscosity reduction effect can be anticipated when it is 20-80 mass parts about reaction curable liquid resin. On the other hand, when it sees about a heat conductive filler, it turned out that there exists a predetermined viscosity reduction effect in the range of 300-842 mass parts with respect to 100 mass parts of liquid resin.
In addition, the E hardness of samples 11 to 16 is E18 to E24, the hardness is slightly increased in the sample with a large amount of the thermally conductive filler, the E hardness of samples 17 and 18 is about E31, and the E hardness of samples 19 and 20 is It was about E38. The heat conductive members of Samples 11, 13, 15, 17, and 19 were heat conductive members having suitable hardness.

  The embodiments and examples described above are exemplifications of the present invention, and within the scope of the present invention, modifications of the embodiments or additions or combinations of known techniques can be performed. Techniques are also within the scope of the present invention.

Claims (9)

A heat conductive composition comprising a reaction curable liquid resin, a non-reactive liquid resin, and a heat conductive filler, wherein the reaction curable liquid resin is cured to form a polymer matrix. Of the 100% by mass of the total resin, 20 to 80% by mass of the reactive curable liquid resin and 20 to 65% by mass of an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol that is a non-reactive liquid resin, 25 A thermally conductive composition having a viscosity at 10 ° C. of 10 to 1000 Pa · s.
The aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol includes an aliphatic polyhydric alcohol having 3 or more hydroxyl groups in a hydrocarbon having 5 to 12 carbon atoms and a carboxyl group in a hydrocarbon having 5 to 12 carbon atoms. The heat conductive composition according to claim 1, which is an ester with an aliphatic monocarboxylic acid provided.
The heat conductive composition according to claim 1 or 2, wherein the reaction curable liquid resin is a nonpolar hydrocarbon polymer having an allyl group at a terminal.
The heat conductive composition of any one of Claims 1-3 which contain 300-1700 mass parts of heat conductive fillers with respect to 100 mass parts of liquid resin.
A thermally conductive member comprising a polymer matrix, a non-reactive liquid resin, and a thermally conductive filler,
The non-reactive liquid resin contains an aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol,
Of the total 100% by mass of the polymer matrix and the non-reactive liquid resin, 20 to 80% by mass of the polymer matrix and 20 to 65% by mass of aliphatic monocarboxylic acid ester of aliphatic polyhydric alcohol are included. Element.
The heat conductive member according to claim 5, wherein the hardness is 0 to 90 in E hardness.
The aliphatic monocarboxylic acid ester of an aliphatic polyhydric alcohol includes an aliphatic polyhydric alcohol having 3 or more hydroxyl groups in a hydrocarbon having 5 to 12 carbon atoms and a carboxyl group in a hydrocarbon having 5 to 12 carbon atoms. The thermally conductive member according to claim 5 or 6, which is an ester with one aliphatic monocarboxylic acid.
The thermally conductive member according to any one of claims 5 to 7, wherein the polymer matrix is a nonpolar hydrocarbon polymer.
  The thermally conductive member according to any one of claims 5 to 8, comprising 300 to 1400 parts by mass of a thermally conductive filler with respect to a total of 100 parts by mass of the polymer matrix and the non-reactive liquid resin.