TWI476261B - Thermal follower - Google Patents

Description

Thermally conductive adhesive

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a thermally conductive adhesive, and more particularly to a thermally conductive adhesive suitable for use in subsequent electronic components and heat dissipating members or heat generating members.

In recent years, with the high performance, miniaturization, and high density of electronic processing devices (CPUs) and chipsets of electronic components such as computers, the heat generation of electronic components and components to which the electronic components are mounted has increased. Therefore, the cooling of the electronic component becomes a very important technique in maintaining the performance of the electronic component and the component on which the electronic component is mounted. The heat dissipation efficiency of an electronic component is generally improved by contacting a material having good thermal conductivity to the electronic component. Therefore, the demand for a heat dissipating material (TIM) having excellent thermal conductivity is increasing.

The heat dissipating material is placed, for example, between the electronic component and a cooling system (e.g., a heat sink) to function to efficiently conduct heat from the heating of the electronic component to the cooling system. The heat dissipating material is classified into a flake-shaped molded product and a paste-like composition from its shape or method of use. The sheet-like molded product is classified into, for example, an elastic (elastic polymer) type heat sink and a thermosoftening type phase change sheet (a sheet using a heat-dissipating material that changes phase with temperature). The paste composition can be classified into, for example, a non-hardening type heat-dissipating paste, and a heat-dissipating gel or a heat-dissipating adhesive which is gelled or gelled by heat treatment, for example, at the time of coating.

Such heat dissipating materials are generally composite materials of high density filled thermal conductive materials in organic polymeric materials. The thermal conductivity of organic polymeric materials is generally small and does not vary greatly depending on the type of organic polymeric material. Thus, the thermal conductivity of the heat dissipating material is highly dependent on the volumetric fill rate in the organic polymeric material of the thermally conductive material. Therefore, it is important to how many thermal conductive materials are filled in the organic polymer material.

Heat-dissipating adhesives are required to have high thermal conductivity while having an adhesive force under various environments or stresses. The higher the density of the organic polymer material is filled with the heat conductive material, the more the heat dissipation property of the heat dissipating material is improved. However, the higher the density of the organic polymer material is filled with the heat conductive material, the heat dissipating material itself becomes brittle, and the flexibility or adhesion to the adherend deteriorates.

The organic polymer material of the heat-dissipating adhesive is known as an epoxy resin, a polyoxyalkylene polymer, a polyimine or the like. However, the epoxy resin has good adhesion, but has disadvantages in heat resistance and durability. Therefore, a polyfluorene oxide polymer can be suitably used for the coating property of the thermal conductive material, the flexibility after curing, the thermal stability, and the like (for example, refer to Patent Documents 1 and 2 below). However, in the heat dissipating material using a polyoxyl polymer, both the adhesion and the heat dissipation property may not be satisfied.

Further, when a polyimide having improved heat resistance is used, since the polyimide resin is solid, it cannot be filled with a heat conductive material, and it has to be dissolved in a solvent or the like to be filled. In order to avoid this, it is necessary to fill the heat-conducting substance with a poly-proline solution which is a precursor, and it is necessary to heat it to 300 ° C or more in the hardening, so that the surrounding heat load cannot be avoided.

Further, in order to protect the surface of a wiring portion such as a semiconductor element or a printed circuit board, it is known that a polyimide resin is used, and the adhesion of a substrate under high-humidity conditions is compared with that of a polyoxyxene rubber. The durability is high (for example, refer to Patent Document 3 below). It has also been disclosed that a composition containing the polyamidene polyoxymethylene resin is used as an adhesive for a semiconductor (for example, refer to Patent Document 4). However, the use of the thermal conductivity adhesive of the polyamidene polyoxyl resin, in particular, the thermal insulating adhesive which requires electrical insulation has not been studied.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2006-342200

[Patent Document 2] Japanese Patent Publication No. 61-3670

[Patent Document 3] JP-A-2002-012667

[Patent Document 4] JP-A-2006-005159

An object of the present invention is to provide an electrically insulating thermal conductive adhesive (also known as a thermal grease) which has excellent thermal conductivity and further excellent adhesion to an adherend such as a heat generating member and a heat dissipating member.

The present invention is a thermally conductive adhesive comprising: (A) 100 parts by mass of a polyamidene polyfluorene resin having a weight average molecular weight of 5,000 to 150,000 of a repeating unit represented by the following formula (1) ( B) an electrically insulating thermally conductive filler of 100 to 10,000 parts by mass, and (C) an organic solvent;

【化1】

(In the formula (1), W is a tetravalent organic group, X is a divalent organic group, and Y is a divalent polyfluorene residue represented by the following formula (2), and 0.05 ≦m ≦ 0.8, 0.2≦n≦0.95, m+n=1)

[Chemical 2]

(In the formula (2), R ^{1 is} independently a substituted or unsubstituted hydrocarbon group having 1 to 8 carbon atoms, R ² is a radical polymerizable group, and a and b are each an integer of 1 to 20, a+ b is 2 to 21).

In one embodiment of the present invention, the thermally conductive adhesive agent further contains (D) a peroxycarbonate in an amount of 0.1 to 10 parts by mass. The peroxycarbonate function acts as a hardener for promoting polymerization hardening of a free polymerizable group.

In one embodiment of the present invention, R ² is a vinyl group, a propenyl group, a (meth) propylene oxypropyl group, a (meth) propylene oxiranyl group, a (meth) propylene fluorenyloxymethyl group, and a benzene group. Vinyl, more preferably vinyl.

In one embodiment of the present invention, the thermal conductive adhesive is used, wherein the bonding strength to the copper plate is 3 MPa or more, more preferably 5 to 10 MPa or more.

When the thermally conductive adhesive of the present invention is placed on a copper plate for heating, the thermally conductive adhesive flows to wet and spread on the surface of the copper plate. Therefore, by heat treatment, it is adhered to the copper plate, resulting in a good adhesion.

The heat conductive adhesive of the present invention is applied to the adherend to harden it. If heated, the adhesive will flow to wet the surface of the adherend, and the solvent will volatilize, so that the thermal conductive filler will be exposed. On the surface of the hardener of the adhesive. Therefore, good thermal conductivity can be obtained.

The present invention provides an electronic component which is obtained by adhering a substance obtained by hardening the above-mentioned thermally conductive adhesive to an electronic component of a heat dissipating member or a heat generating member.

The thermally conductive adhesive of the present invention has excellent thermal conductivity and a superior adhesion to an adherend by containing a polyfluorene-polyoxyl resin having a specific structure, a thermally conductive filler, and an organic solvent.

[Formation for implementing the invention]

Hereinafter, the thermally conductive adhesive of the present invention will be described in more detail.

(A) Polyimine Polysiloxane The polyimine polyoxyl resin has a repeating unit represented by the following formula (1).

[化3]

W in the formula (1) is a tetravalent organic group. The W system may be selected, for example, from pyromellitic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride. , 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 3,3',4,4' - benzophenone tetracarboxylic dianhydride, ethylene glycol trimellitic acid dianhydride, 4,4'-hexafluoropropylene bismuthic acid dianhydride, 2,2-bis[4-(3,4 Residue of -phenoxydicarboxylic acid)phenyl]propionic acid dianhydride.

X in the formula (1) is a divalent organic group. X is a group derived from a diamine which can be used, for example, in a conventional polyimine resin. The diamine may be a combination of one or more of an aliphatic diamine and an aromatic diamine. The aliphatic diamine is, for example, tetramethylenediamine, 1,4-diaminocyclohexane or 4,4'-diaminodicyclohexylmethane. The aromatic diamine is, for example, phenylenediamine, 4,4'-diaminodiphenyl ether or 2,2-bis(4-aminophenyl)propane. X is preferably a group derived from an aromatic diamine represented by the following formula (3).

【化4】

B in the formula (3) is a group represented by any one of the following formulas (4), (5), and (6).

【化5】

【化6】

【化7】

Y in the formula (1) is a divalent polyfluorene residue represented by the following formula (2).

【化8】

R ¹ in the formula (2) is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. R ^{1 is,} for example, a methyl group or an ethyl group.

R ² in the formula (2) is a radical polymerizable group. R ² is, for example, a vinyl group, a propenyl group, a (meth)acryloxypropyl group, a (meth)acryloyloxyethyl group, a (meth)acryloxymethyl group, or a styryl group. Preferably, R ² is a vinyl group from the viewpoint that the raw material is easily obtained. When the radical polymerizable group is a polyoxymethylene portion of the polyamidene polyoxynene resin, it may be, for example, a portion of either the end portion or the center portion.

In the formula (2), a and b are each 1 to 20, and preferably an integer of 3 to 20. The total of a+b is 2 or more and 21 or less. Here, when a and b are each greater than 20, or a+b is larger than 21, the adhesion to the adherend becomes weak.

The m and n systems in the formula (1) exhibit an effect derived from the repeating unit, 0.05 ≦ m ≦ 0.8, 0.2 ≦ n ≦ 0.95, preferably 0.05 ≦ m ≦ 0.5, 0.5 < n ≦ 0.95. If it is this range, good adhesion to the adherend can be obtained.

The total of m+n in the formula (1) is 1.

The polyamidene polyoxyl resin has a weight average molecular weight of 5,000 to 150,000, preferably 20,000 to 150,000. For this reason, if the molecular weight is less than the above lower limit, the toughness of the resin is not exhibited, and if the molecular weight is more than the above upper limit, it is difficult to mix with the thermally conductive filler described later.

The polyamidene polyoxysiloxane resin can be produced, for example, by a known method described below.

Initially, a tetracarboxylic dianhydride for derivatization W, a diamine for derivatizing X, and a diamine polyoxyalkylene for deriving Y are fed into a solvent, and then reacted at a low temperature, for example, 0 to 50 ° C. . The solvent is selected from, for example, a combination of N-methyl-2-pyrrolidone (NMP), cyclohexanone, γ-butyrolactone, and N,N-dimethylacetamide (DMAc) of 1 or more. Further, the water formed during the imidization of the hydrazine is easily removed by azeotropic removal, so that aromatic hydrocarbons such as toluene or xylene can be used in combination. The precursor of the quinone imine resin, that is, polydecanoic acid, can be produced according to the above reaction. Next, the solution of the poly-proline is heated to a temperature of preferably from 80 to 200 ° C, particularly preferably from 140 to 180 ° C. A solution of the polyamidene polyoxyxylene resin can be obtained by the dehydration ring closure reaction of the acid amide of the polyaminic acid at this temperature rise. The solution is placed in a solvent such as water, methanol, ethanol or acetonitrile to produce a precipitate. The resulting precipitate is dried to obtain a polyamidene polyoxymethylene resin.

The molar ratio of the total of the diamine of the tetracarboxylic dianhydride to the diamine polyoxyalkylene is preferably from 0.95 to 1.05, particularly preferably from 0.98 to 1.02.

To adjust the molecular weight of the polyimine polyoxyl resin, a difunctional carboxylic acid such as phthalic anhydride, and a monofunctional amine such as aniline may also be added to the above solution. The amount of these compounds added is, for example, 2 mol% or less based on the tetracarboxylic acid and the diamine.

In the process of hydrazine imidization, a dehydrating agent and a ruthenium-imiding catalyst are added, and if necessary, heating is carried out at about 50 ° C, and ruthenium can also be imidized. The dehydrating agent is, for example, an acid anhydride such as acetic anhydride, propionic anhydride, and trifluoroacetic anhydride. The amount of the dehydrating agent used is, for example, 1 to 10 moles per diamine. The quinone imidization catalyst is, for example, a tertiary amine such as pyridine, choline, lutidine, and triethylamine. The amount of the ruthenium-based catalyst used is, for example, 0.5 to 10 moles per mole of the dehydrating agent to be used.

When a plurality of diamines and/or a plurality of tetracarboxylic dianhydrides are used, for example, a raw material is mixed in advance and then copolymerized and condensed, and two or more kinds of diamines or tetracarboxylic dianhydrides are separately reacted and sequentially added. . However, the reaction method is not particularly limited to this illustration.

(B) Electrically insulating thermal conductive filler

The electrically insulating thermally conductive filler is, for example, a metal oxide and a ceramic powder. The metal powder is, for example, zinc oxide powder or alumina powder. The ceramic powder is, for example, tantalum carbide powder, tantalum nitride powder, boron nitride powder, or aluminum nitride powder. The thermally conductive filler may be suitably selected from the viewpoints of stability or cost.

The shape of the thermally conductive filler is not particularly limited, and is, for example, a granular shape, a dendritic shape, a sheet shape, and an indefinite shape. One or a mixture of two or more kinds of thermally conductive filler powders having such shapes may also be used. The particle size distribution of the thermally conductive filler is not particularly limited, and is, for example, 90% by weight or more in the range of 0.05 to 100 μm, preferably 95% by weight or more. The average particle diameter of the thermally conductive filler is not particularly limited, but is, for example, in the range of 1 to 50 μm. As the thermally conductive filler, for example, a single distribution (monomodality) can be used. However, in order to disperse the thermally conductive filler in a high density and uniformly dispersed in the adhesive, a plurality of thermally conductive fillers having different shapes and particle diameters are combined to form a multimodal distribution, which is more effective than using a single distributed thermally conductive filler. .

The ratio of the amount of the thermally conductive filler to be added to the thermally conductive adhesive of the present invention is from 100 to 10,000 parts by mass, preferably from 200 to 6,000 parts by mass, per 100 parts by mass of the polyamidene polyoxyalkylene resin. When the ratio of the amount of the thermally conductive filler is less than the above lower limit, sufficient thermal conductivity cannot be obtained when the thermally conductive adhesive of the present invention is used. Further, when the ratio of the amount of the thermally conductive filler to be added exceeds the above upper limit, when the thermally conductive adhesive of the present invention is used, sufficient adhesive strength cannot be obtained between the adherend and the adherend.

(C) organic solvent

The organic solvent is compatible with the component (A), and it is preferred not to affect the surface state of the component (B). The organic solvent is, for example, a combination of one or more selected from the group consisting of ethers, ketones, esters, cellosolves, guanamines, and aromatic hydrocarbons. The ethers contain, for example, tetrahydrofuran, and anisole. The ketones include, for example, cyclohexanone, 2-heptanone, methyl isobutyl ketone, 2-heptanone, 2-octanone, and acetophenone. The esters contain, for example, butyl acetate, methyl benzoate, and γ-butyrolactone. The cellosolve contains, for example, butyl carbitol acetate, butyl cellosolve acetate, and propylene glycol monomethyl ether acetate. The guanamines contain, for example, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The aromatic hydrocarbons contain, for example, toluene or xylene. The organic solvent is preferably selected from the group consisting of ketones, esters, cellosolves, and guanamines. The organic solvent is particularly preferably butyl carbitol acetate, γ-butyrolactone, propylene glycol monomethyl ether acetate, and N-methyl-2-pyrrolidone. These solvents may be used alone or in combination of two or more.

The amount of the organic solvent is, for example, considering the solubility of the polyimide, the workability of the thermal conductive adhesive or the thickness of the film, and the amount of the polyamidene polyoxyl resin is generally relative to the resin. The total amount of the solvent is from 10 to 60% by weight, preferably from 20 to 50% by weight. The composition is prepared to a relatively high concentration when stored, and may be diluted to a desired concentration during use.

The thermally conductive adhesive of the present invention may further contain (D) peroxycarbonate as an optional component. In the presence of a peroxycarbonate, even if it is relatively low temperature, the radical polymerizable group bonded to the ruthenium atom in the polyamidene polysiloxane resin is rapidly hardened, and the performance such as solvent resistance is improved. Examples of the peroxycarbonate include a single butyl peroxy isopropyl carbonate, a third butyl peroxy 2-ethylhexyl carbonate, and a third pentyl peroxide 2-ethylhexyl carbonate. Peroxycarbonate; bis(2-ethylhexyl)peroxydicarbonate, 1,6-bis(t-butylperoxycarbonyloxy)hexane, bis(4-tert-butylcyclohexyl)peroxidation Dicarbonate, bis(2-ethoxyethyl)peroxydicarbonate, di(n-propyl)peroxydicarbonate, diisopropylperoxydicarbonate, and the like. The peroxycarbonate is preferably a third butyl peroxy 2-ethylhexyl carbonate, or the like, in terms of curability, compatibility with a polyamidene polyoxymethylene resin, and storage stability of an adhesive. Tripentylperoxide 2-ethylhexyl carbonate, 1,6-bis(t-butylperoxycarbonyloxy)hexane, bis(4-t-butylcyclohexyl)peroxydicarbonate.

The amount of the peroxycarbonate is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the polyamidene polyfluorene resin. When the blending amount exceeds the above upper limit, the storage stability of the thermally conductive adhesive of the present invention and the high temperature and high wettability of the cured product tend to be lowered.

The polyimide polyimide polyether resin exhibits excellent heat resistance, mechanical strength, solvent resistance, and adhesion to various substrates by thermal curing.

The curing conditions of the adhesive of the present invention are not particularly limited, but are preferably 80° C. or higher and 300° C. or lower, and preferably 100° C. or higher and 200° C. or lower. When the hardening is not carried out below the lower limit, it is too time-consuming to be thermally hardened, and it is not practical. When the curing is carried out at a low temperature which does not reach the above lower limit, the stability and stability of the adhesive may cause problems when the composition and composition are selected. Further, the thermally conductive adhesive of the present invention is different from the conventional polyamic acid solution, and it is not required to be heated at a high temperature of 300 ° C or higher for a long period of time for curing, so that thermal deterioration of the substrate can be suppressed.

The thermal conductive adhesive of the present invention may contain, in addition to the above components, an anti-aging agent, an ultraviolet absorber, an adhesion improver, a flame retardant, and an interface, without departing from the object of the present invention and the effect of the thermal conductive adhesive. Active agent, preservation stability improver, ozone degradation inhibitor, light stabilizer, tackifier, plasticizer, decane coupling agent, antioxidant, thermal stabilizer, radiation shielding agent, nucleating agent, slip agent, pigment, and physical property The regulator is selected to be 1 or more.

The thermally conductive adhesive of the present invention preferably has a viscosity of from 0.5 to 2,000 Pa s at 25 ° C, preferably from 1.0 to 1,000 Pa ‧ s.

The thermal conductivity (W/mK) of the thermally conductive adhesive of the present invention is preferably 0.5 or more, more preferably 1.0 or more, and particularly preferably 3 or more.

The thermal strength of the thermal conductive adhesive of the present invention to the copper plate is preferably 3 or more, more preferably 5 or more, and particularly preferably 6 or more. The bonding strength (MPa) after leaving it at a temperature of 80 ° C and 95 RH for 240 hours is preferably the same as above.

The thermal conductive adhesive of the present invention can be suitably used, for example, as an adhesive for an LED chip having a large amount of heat for high luminance, or as an adhesive for a semiconductor element having a large amount of heat per unit area which is reduced in size and weight.

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited thereto.

1. Synthesis of polyamidene polyoxyl resin

Four kinds of polythenimine polyfluorene resins were produced as shown in the following Synthesis Examples 1 to 4.

Synthesis Example 1

In a flask equipped with a stirrer, a thermometer and a nitrogen substitution device, 88.8 g (0.2 mol) of 4,4'-hexafluoropropylenebisphthalic acid dianhydride and 500 g of n-methyl-2-pyrrolidone were fed. Then, 142.2 g (0.16 mol) and 2,2-bis[4-(4-aminophenoxy)phenyl]propane as shown in Formula 7 were prepared, 16.4 g (0.04). Mohr) was dissolved in a solution of 100 g of n-methyl-2-pyrrolidone. This solution was dropped into the above flask. At the time of dripping, the temperature of the reaction system was adjusted to avoid exceeding 50 °C. After the completion of the dropwise addition, the mixture was further stirred at room temperature for 10 hours. Then, after installing a reflux condenser equipped with a water receiver in the flask, 50 g of xylene was added, and the temperature was raised to 150 ° C, and the temperature was maintained for 6 hours. As a result, a yellow-brown solution was obtained.

【化9】

The yellow-brown solution obtained above was cooled to room temperature (25 ° C), and poured into methanol to reprecipitate. The obtained precipitate was dried (190 g), and its linear absorption spectrum was measured. As a result, the absorption of the unreacted polylysine (1640 cm ^-1 ) was not observed, and it was confirmed that the absorption was based on the quinone imine group at 1780 cm ^-1 and 1720 cm ^-1 . Next, the result of measuring the weight average molecular weight (in terms of polystyrene) by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent was 33,000. The product is referred to as a polyamidene polyoxyl resin (1).

Synthesis Example 2

In a flask equipped with a stirrer, a thermometer and a nitrogen substitution device, 88.8 g (0.2 mol) of 4,4'-hexafluoropropylenebisphthalic acid dianhydride and 500 g of n-methyl-2-pyrrolidone were fed. Then, 165.3 g (0.1 mol) of diaminocarboxane represented by Formula 8 and 41.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane were prepared. Mohr) was dissolved in a solution of 100 g of n-methyl-2-pyrrolidone. This solution was dropped into the above flask. At the time of dripping, the temperature of the reaction system was adjusted to avoid exceeding 50 °C. After the completion of the dropwise addition, the mixture was further stirred at room temperature for 10 hours. Then, after installing a reflux condenser equipped with a water receiver in the flask, 50 g of xylene was added, and the temperature was raised to 150 ° C, and the temperature was maintained for 6 hours. As a result, a yellow-brown solution was obtained.

【化10】

The yellow-brown solution obtained above was cooled to room temperature (25 ° C), and poured into methanol to reprecipitate. 240 g of the obtained precipitate was dried, and its linear absorption spectrum was measured. As a result, the absorption of the unreacted polylysine (1640 cm ^-1 ) was not observed, and it was confirmed that the absorption was based on the quinone imine group at 1780 cm ^-1 and 1720 cm ^-1 . Next, the result of measuring the weight average molecular weight (in terms of polystyrene) by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent was 33,000. The product is referred to as a polyamidene polyoxyl resin (2).

Synthesis Example 3 (for comparison)

In a flask equipped with a stirrer, a thermometer and a nitrogen substitution device, 88.8 g (0.2 mol) of 4,4'-hexafluoropropylenebisphthalic acid dianhydride and 500 g of n-methyl-2-pyrrolidone were fed. Then, 263.1 g (0.08 mol) of diaminocarboxane represented by Formula 9, and 49.3 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane were prepared (0.12). Mohr) was dissolved in a solution of 100 g of n-methyl-2-pyrrolidone. This solution was dropped into the above flask. At the time of dripping, the temperature of the reaction system was adjusted to avoid exceeding 50 °C. After the completion of the dropwise addition, the mixture was further stirred at room temperature for 10 hours. Then, after installing a reflux condenser equipped with a water receiver in the flask, 50 g of xylene was added, and the temperature was raised to 150 ° C, and the temperature was maintained for 6 hours. As a result, a yellow-brown solution was obtained.

【化11】

The yellow-brown solution obtained above was cooled to room temperature (25 ° C), and poured into methanol to reprecipitate. The obtained precipitate was 330 g, and its linear absorption spectrum was measured. As a result, the absorption of the unreacted polylysine (1640 cm ^-1 ) was not observed, and it was confirmed that the absorption was based on the quinone imine group at 1780 cm ^-1 and 1720 cm ^-1 . Next, the result of measuring the weight average molecular weight (in terms of polystyrene) by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent was 35,000. The product is referred to as a polyamidene polyoxyl resin (3).

Synthesis Example 4 (for comparison)

In a flask equipped with a stirrer, a thermometer and a nitrogen substitution device, 88.8 g (0.2 mol) of 4,4'-hexafluoropropylenebisphthalic acid dianhydride and 500 g of n-methyl-2-pyrrolidone were fed. Then, 244.8 g (0.08 mol) of diaminocarboxane represented by formula (10) and 49.3 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane were prepared. (0.12 mol) was dissolved in a solution of 100 g of n-methyl-2-pyrrolidone. This solution was dropped into the above flask. At the time of dripping, the temperature of the reaction system was adjusted to avoid exceeding 50 °C. After the completion of the dropwise addition, the mixture was further stirred at room temperature for 10 hours. Then, after installing a reflux condenser equipped with a water receiver in the flask, 50 g of xylene was added, and the temperature was raised to 150 ° C, and the temperature was maintained for 6 hours. As a result, a yellow-brown solution was obtained.

【化12】

The yellow-brown solution obtained above was cooled to room temperature (25 ° C), and poured into methanol to reprecipitate. The obtained precipitate was dried (340 g), and its linear absorption spectrum was measured. As a result, the absorption of the unreacted polylysine (1640 cm ^-1 ) was not observed, and it was confirmed that the absorption was based on the quinone imine group at 1780 cm ^-1 and 1720 cm ^-1 . Next, the result of measuring the weight average molecular weight (in terms of polystyrene) by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent was 35,000. The product is referred to as a polyamidene polyoxyl resin (4).

2. Preparation of adhesive

The following materials were used.

(A) Polyimine polyoxyl resin: used in the polyamidene polyoxyl resin (1), (2), (3), or (4) obtained in the above Synthesis Examples 1 to 4.

(B) Electrically insulating thermal conductive filler:

(B1) Thermally conductive filler A: alumina having an average particle diameter of 10 μm (specific gravity: 3.98)

(B2) Thermally conductive filler B: alumina having an average particle diameter of 1 μm (specific gravity: 3.98)

(C) Organic solvent: butyl carbitol acetate (BCA)

(D) Peroxycarbonate: tert-butylperoxy-2-ethylhexyl carbonate

[Examples 1 to 4 and Comparative Examples 1 to 2]

(A) Polyimine polysiloxane resins (1) to (4) respectively (B) electrically insulating thermally conductive fillers (B1 and B2), (C) organic solvents, and (D) peroxycarbonic acid The ester was fed into the autorotation mixer at a mass ratio shown in Table 1, and the mixture was stirred to be uniform, and then defoamed to obtain an adhesive.

3. Evaluation test

With respect to the adhesives obtained in Examples 1 to 4 and Comparative Examples 1 and 2, evaluation tests of viscosity, thermal conductivity, and adhesion strength were carried out in the following manner. Further, the heat-curable one-liquid type polyoxyethylene rubber C (commercial product) and D (commercial product) were subjected to evaluation tests in the same order as above (Comparative Example 3 and Comparative Example 4, respectively).

The results are shown in Table 2.

(1) Viscosity

The viscosity of each adhesive was measured at 25 ° C using a BH type rotational viscometer.

(2) Thermal conductivity

Each of the adhesives was poured into a groove of Teflon (trademark) (manufactured by DuPont), dried at 80 ° C for 30 minutes, and then the adhesive was heated at 150 ° C for 1 hour to prepare a test piece of 10 mm Φ × 1 mm. The thermal diffusivity and specific heat capacity of the test piece were measured using a laser flash thermal constant measuring apparatus (LFA 447 (manufactured by NETZSCH)) to determine the thermal conductivity.

(3) subsequent strength

Each of the adhesives was applied to a copper plate (100 mm × 25 mm × 1 mm) at a coating area of 20 mm × 20 mm, and bonded to another copper plate of the same size. The bonded copper plate was dried at 80 ° C for 30 minutes, and then further dried at 150 ° C for 2 minutes under a pressure of 4 MPa, followed by heating at 150 ° C for 1 hour to obtain a test piece. The shear strength of the test piece was measured at a speed of 5 mm/min using Autograph (STROGRAPH V10-D (manufactured by Toyo Seiki Co., Ltd.)).

Further, the test piece obtained in the same manner as above was exposed to air at 80 ° C / 95% RH for 240 hours (high temperature and high humidity test), and the shear strength was measured in the same manner as above (after the high temperature and high humidity test).

From the above results, the adhesives 1 to 4 have an appropriate viscosity, the thermal conductivity is preferably 1.1 to 3.1 W/mK, and the strength is preferably 6 to 11 MPa, and the decrease in the adhesion strength before and after the high temperature and high humidity test is hardly observed. .

Claims (5)

A thermally conductive adhesive comprising: (A) a polyilylimine polyfluorene resin having a weight average molecular weight of 5,000 to 150,000 by a repeating unit represented by the following formula (1): 100 parts by mass (B) electrical insulation The thermally conductive filler is 100 to 10,000 parts by mass, and (C) an organic solvent; In the formula (1), W is selected from pyromellitic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetra Carboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, ethylene glycol trimellitic acid dianhydride, 4,4'-hexafluoropropylene bismuthic acid dianhydride, or 2,2-bis[4 a tetravalent organic group of a residue of -(3,4-phenoxydicarboxylic acid)phenyl]propionic acid dianhydride, and X is one or more selected from the group consisting of aliphatic diamines and aromatic diamines. Combining the divalent organic group derived, Y is a divalent polyoxyl residue represented by the following formula (2), and 0.05≦m≦0.8, 0.2≦n≦0.95, m+n=1; In the formula (2), R ^{1 is} independently a substituted or unsubstituted one-valent hydrocarbon group having 1 to 8 carbon atoms, R ² is a radical polymerizable group, and a and b are each an integer of 1 to 20, and a+b is 2~21. The thermally conductive adhesive of claim 1, wherein R ² is selected from the group consisting of vinyl, propylene, (meth) propylene oxypropyl, (meth) propylene oxiranyl, (meth) propylene A group consisting of a methoxymethyl group and a styryl group. The thermally conductive adhesive according to claim 1 or 2, further comprising (D) a peroxycarbonate in an amount of 0.1 to 10 parts by mass. The thermally conductive adhesive according to claim 1 or 2, wherein the bonding strength to the copper sheet is 3 MPa or more. An electronic component comprising a material obtained by curing a thermally conductive adhesive agent according to any one of claims 1 to 4, followed by an electronic component of a heat dissipating member or a heat generating member.