JP6680035B2 - Thermal conductive sheet - Google Patents

Description

  The present invention relates to a heat conductive sheet satisfying high heat conductivity, heat resistance, moist heat resistance and heat cycle resistance.

2. Description of the Related Art In recent years, the development of the electronics field has been remarkable, and in particular, the miniaturization, weight reduction, high density, and high output of electronic devices have advanced, and the requirements for these performances have become more and more advanced. High insulation reliability and miniaturization are required for high density electronic circuits. Further, there is a demand for improvement of heat dissipation to prevent deterioration of the electronic device due to heat generation due to higher output of the electronic device.
As a conventional heat dissipation structure applied to heat-generating electronic devices, a heat conductive sheet in which heat conductive particles are arranged in a sheet made of a polymer material to improve heat conductivity has been developed. There is.
The heat conductive sheet is required to have high heat conductivity, heat resistance, resistance to moist heat, and heat cycle resistance. Especially in electrical parts applications such as automotive electrical parts, peeling and cracks occur at the adhesive part due to thermal stress due to the difference in thermal expansion coefficient due to temperature changes, resulting in reduced insulation and thermal resistance. Therefore, high heat cycle resistance is required.

Therefore, in order to solve these requirements, for example, Patent Document 1 proposes a highly flexible heat conductive sheet using an acrylic urethane resin. Patent Document 2 proposes a heat conductive sheet having excellent heat conductivity in the surface direction and excellent conformability to unevenness. Patent Document 3 proposes a polyester resin obtained by copolymerizing dimer acid in order to impart flexibility.
Further, in Patent Document 4, a heat conductive sheet using an epoxy resin is
Patent Document 5 proposes a laminate in which a circuit board is laminated on a heat dissipation plate via a cured product layer of an adhesive containing a phenolic hydroxyl group-containing aromatic polyamide (A) and an epoxy resin (B). .
Further, Patent Document 6 proposes that an epoxy resin composition containing an epoxy resin, a phenol resin, and a phenolic hydroxyl group-containing aromatic polyamide is used as a sealing material, an adhesive, a paint, or the like.

  Further, Patent Document 7 discloses a thermoplastic resin (A), a filler (B), and a melt viscosity reducing agent which utilize a melt viscosity reducing agent (C) and have excellent melt fluidity during processing such as injection molding. A resin composition containing (C) is described. The filler (B) is a heat conductive filler (B1), the melt viscosity reducing agent (C) is a dimer acid-based thermoplastic resin (C2), and the dimer acid base thermoplastic resin (C2) is a polyamide. Resins and polyester resins are described.

  Furthermore, as a thermosetting resin composition that is not a heat conductive sheet but is in the technical field of printed wiring boards, it is a thermosetting resin composition that is rich in flexibility and can form a cured product with a low dielectric constant and low dielectric loss tangent. A polyamide containing a hydroxyl group and a specific structure, and a compound containing a trifunctional or higher functional compound capable of reacting with the phenolic hydroxyl group are disclosed.

JP, 2002-30212, A JP, 2013-179277, A JP 2012-117044 A JP, 2008-189818, A WO2011 / 114665 JP 2000-313787 A WO2010 / 08485 WO2016 / 001949

However, in Patent Document 1, since urethane resin is used, heat resistance and moist heat resistance are insufficient. Further, in Patent Document 2, the thermal conductivity in the thickness direction cannot be said to be sufficient, and since a rubber component is added to impart flexibility, the heat resistance is insufficient. Further, in Patent Document 3, since a polyester resin having low hydrolysis resistance is used, the moist heat resistance is insufficient. Further, in Patent Documents 4 to 6, since the epoxy resin and aromatic polyamide used are very hard and lack flexibility, thermal stress due to the difference in thermal expansion coefficient due to temperature change cannot be relaxed, Problems such as peeling and cracking due to heat cycle will occur.
Further, the resin composition in Patent Document 7 is for use in injection molding, and the resin (A) and the melt viscosity reducing agent (C) used are both thermoplastic, and the resin composition has heat resistance. Can't expect.

  An object of the present invention is to provide a heat conductive sheet which has both high heat conductivity, heat resistance, moist heat resistance and heat cycle resistance.

  In order to solve the above problems, the inventors of the present invention have made extensive studies and found that by using a specific phenolic hydroxyl group-containing polyamide resin, both high thermal conductivity and heat resistance / moist heat resistance and heat cycle resistance are achieved. Was found.

That is, the heat conductive sheet of the present invention is a polymer of a polybasic acid monomer and a polyamine monomer, and can react with the polyamide (A) having a phenolic hydroxyl group in the side chain and the phenolic hydroxyl group. A thermally conductive sheet containing a trifunctional or higher functional compound (B) and a thermally conductive filler (C), wherein the polyamide (A) is the following (i) and / or (ii): , (Iii) to (vi), and the compound (B) satisfies the following (vii).
(I) The polyamide (A) is a polyamide (A- in which the phenolic hydroxyl group and the hydrocarbon group having 20 to 60 carbon atoms (however, the aromatic ring to which the phenolic hydroxyl group is bonded are not included) are contained in the same polymer. 1).
(Ii) The polyamide (A) is a polyamide (A-) obtained by mixing a polyamide (a-1) containing a phenolic hydroxyl group in a side chain and a polyamide (a-2) containing a hydrocarbon group having 20 to 60 carbon atoms. 3).
(Iii) As the monomer constituting the polyamide (A-1), a monomer having a phenolic hydroxyl group and a monomer having a hydrocarbon group having 20 to 60 carbon atoms are included.
(Iv) The polybasic acid monomer or / and the polyamine monomer constituting the polyamide (a-1) contains a monomer having a phenolic hydroxyl group, and the polybasic acid monomer and The polyamine monomer does not include a monomer having a hydrocarbon group having 20 to 60 carbon atoms.
(V) The polybasic acid monomer and / or the polyamine monomer forming the polyamide (a-2) contains a monomer having a hydrocarbon group having 20 to 60 carbon atoms, and The basic acid monomer and the polyamine monomer do not include a monomer having a phenolic hydroxyl group.
(Vi) At least a part of the monomer having a hydrocarbon group having 20 to 60 carbon atoms includes a compound having a cyclic structure having 5 to 10 carbon atoms.
(Vii) The compound (B) is at least one selected from the group consisting of an epoxy group-containing compound, an isocyanate group-containing compound, a carbodiimide group-containing compound, a metal chelate, a metal alkoxide and a metal acylate.

  By using a phenolic hydroxyl group-containing polyamide resin that is soluble in general-purpose organic solvents and has excellent heat resistance, hydrolysis resistance, and flexibility, and a heat conductive filler, it has high heat conductivity and heat resistance. It is possible to obtain a heat conductive sheet having high heat resistance, moist heat resistance and heat cycle resistance.

  As described above, the heat conductive sheet of the present invention is a composition containing a heat conductive filler (C) and a resin component, wherein the resin component is a phenolic hydroxyl group-containing polyamide (A) and the phenolic hydroxyl group. It contains a compound (B) having three or more functional groups capable of reacting.

The heat resistant resin component used in the present invention will be described below.
In the present invention, a specific phenolic hydroxyl group-containing polyamide resin (A) and a trifunctional or higher functional compound (B) capable of reacting with the phenolic hydroxyl group are used as heat resistant resin components. By using these, the thermal stress can be relaxed without lowering the heat resistance.

<Phenolic hydroxyl group-containing polyamide (A)>
The phenolic hydroxyl group-containing polyamide resin (A) used in the bonding agent of the present invention is a polyamide (A) containing a phenolic hydroxyl group in its side chain (hereinafter, also referred to as “phenolic hydroxyl group-containing polyamide (A)”). It contains a trifunctional or higher functional compound (B) capable of reacting with the above-mentioned phenolic hydroxyl group (hereinafter, also referred to as “compound (B)”). The method for synthesizing the polyamide (A) is not limited, but the polybasic acid compound selected from dibasic or higher polybasic acids and / or acid anhydrides and / or lower alkyl esters thereof is usually used as the monomer, and It is synthesized using a polyamine compound having a valency or more. The phenolic hydroxyl group in the polyamide (A) can form a crosslinked structure by heat curing with the trifunctional or higher functional compound (B).

  The polyamide (A) in the present invention is a polyamide (i) in which the phenolic hydroxyl group and the hydrocarbon group having 20 to 60 carbon atoms (however, the aromatic ring to which the phenolic hydroxyl group is bonded are not included) are contained in the same polymer ( A-1) and / or (ii) a polyamide (a-1) containing a phenolic hydroxyl group in the side chain and a hydrocarbon group having 20 to 60 carbon atoms (however, the aromatic ring to which the phenolic hydroxyl group is bonded is included. It is a polyamide (A-3) which is a mixture of a polyamide (a-2) containing the same). The former polyamide (A-1) is preferable in terms of solubility in a general-purpose solvent and productivity. In the following description, parentheses of a hydrocarbon group having 20 to 60 carbon atoms (however, the aromatic ring to which the phenolic hydroxyl group is bonded are not included) are omitted, but "hydrocarbon group having 20 to 60 carbon atoms" ", The above parenthesized condition is satisfied. Moreover, the "hydrocarbon group having 20 to 60 carbon atoms" is also referred to as "C20 to 60 hydrocarbon group". Further, the hydrocarbon group having 20 to 60 carbon atoms means a hydrocarbon group having 20 to 60 carbon atoms contained in all or a part of the residues other than the functional group contributing to the polymerization of the monomer. Count the number of carbons in a continuous structure that does not contain elements other than hydrogen. More preferably, all the residues other than the functional groups that contribute to the polymerization of the monomer are hydrocarbon groups having 20 to 60 carbon atoms. That is, it refers to the total number of carbon atoms of a continuous hydrocarbon group including the main chain and side chains directly connected to the main chain with respect to the obtained polyamide (A-1), and other than aliphatic (including alicyclic) , Aromatic rings are also counted. However, the aromatic ring to which the phenolic hydroxyl group is bonded is not included. Further, the hydrocarbon groups bonded via the aromatic ring to which the phenolic hydroxyl group is bonded are counted as different hydrocarbon groups.

   The polyamide (A) satisfies the following (iii) to (vi). That is, (iii) the monomer constituting the polyamide (A-1) includes a monomer having a phenolic hydroxyl group and a monomer having a hydrocarbon group having 20 to 60 carbon atoms. Needless to say, a monomer having a phenolic hydroxyl group and a hydrocarbon group having 20 to 60 carbon atoms may be used in the same type of monomer. (Iv) Polybasic acid monomer or / and polyamine monomer constituting polyamide (a-1) contains a monomer having a phenolic hydroxyl group, and polybasic acid monomer and polyamine monomer The body does not include a monomer having a hydrocarbon group having 20 to 60 carbon atoms. (V) The polybasic acid monomer and / or polyamine monomer constituting the polyamide (a-2) contains a monomer having a hydrocarbon group having 20 to 60 carbon atoms, and the polybasic acid monomer The monomer and polyamine monomer do not include a monomer having a phenolic hydroxyl group. (Vi) The monomer having a hydrocarbon group having 20 to 60 carbon atoms includes a compound having a cyclic structure having 5 to 10 carbon atoms. In addition, "the compound which has a C5-C10 cyclic structure is included" means that the C5-C10 cyclic structure is contained in at least one part of the monomer which has a C20-C60 hydrocarbon group. Is meant to include a monomer having

  The monomer having a hydrocarbon group having 20 to 60 carbon atoms is more preferably a monomer having a hydrocarbon group having 24 to 56 carbon atoms, from the viewpoint of effectively drawing out solubility and flexibility. A monomer having a hydrocarbon group of 28 to 48 is more preferable, and a monomer having a hydrocarbon group of 36 to 44 is more preferable.

<< Polyamide (A-1) >>
The polyamide (A-1) is obtained by polymerizing a polybasic acid monomer (m1) and a polyamine monomer (m2), has a phenolic hydroxyl group in the side chain, and is phenolic in the same polymer. It has a hydroxyl group and a C20-60 hydrocarbon group. As long as the above conditions are satisfied, polybasic acid monomers and polyamine monomers having other structures can be appropriately used without departing from the spirit of the present invention. That is, the polybasic acid monomer (m1) is at least one selected from the group consisting of a polybasic acid compound having a phenolic hydroxyl group, a polybasic acid compound containing a C20-60 hydrocarbon group, and other polybasic acid compounds. Therefore, the polyamine monomer (m2) is at least one selected from the group consisting of a polyamine compound having a phenolic hydroxyl group, a polyamine compound having a C20-60 hydrocarbon group, and other polyamine compounds, and a phenolic hydroxyl group in the polymer. And C20-60 hydrocarbon groups may be included. The compound having a C20-60 hydrocarbon group and the compound having a phenolic hydroxyl group are contained in the same monomer or in another monomer so that the polybasic acid monomer (m1) and the polyamine monomer The phenolic hydroxyl group-containing polyamide (A-1) can be obtained by selecting and polymerizing the monomer (m2).

  That is, "to be contained in the same kind of monomer" means a polybasic acid compound having a phenolic hydroxyl group as the polybasic acid monomer (m1) and a polybasic acid compound containing a C20-60 hydrocarbon group. Or a polyamine compound having a phenolic hydroxyl group as the polyamine monomer (m2) and a polyamine compound containing a C20-60 hydrocarbon group may be used. Further, "to be contained in another monomer" includes a polybasic acid compound having a phenolic hydroxyl group as the polybasic acid monomer (m1), and C20 to 60 as the polyamine monomer (m2). A polyamine compound containing a hydrocarbon group may be contained, or a polybasic acid compound containing a C20-60 hydrocarbon group may be contained as the polybasic acid monomer (m1), and the polyamine monomer (m2) may be phenolic. It is meant that a polyamine compound having a hydroxyl group may be contained. In any case, other polybasic acid compounds and other polyamine compounds can be used appropriately.

  The phenolic hydroxyl group introduced into the side chain of the main chain produced by the polymerization of the polybasic acid monomer (m1) and the polyamine monomer (m2) serves as a crosslinking point. That is, a dense crosslinked structure can be formed by thermosetting the polyamide (A-1) and the trifunctional or higher functional compound (B) capable of reacting with a phenolic hydroxyl group described later.

When the polyamide (A) is obtained using a dibasic acid monomer and a diamine monomer, it has a structural unit represented by the following general formula (1).

In the general formula (1), R ₁ is a divalent linking group that is a polybasic acid compound residue that may have an independent structure for each structural unit, and R ₂ is independent for each structural unit. structure is a divalent linking group is a good polyamine compound residue which may have a, at least one of R ₁ and R ₂ includes a linking group having a phenolic hydroxyl group, and R ₁ and R ₂ At least one includes a linking group having a C20-60 hydrocarbon group. Polyamide (A-1) _is to _{-CO-R 1 -CO-NH-} R 2 -NH- with structural unit represented is repeated at least 2 or more. In addition, a compound having one structural unit represented by the general formula (1) and having a terminal blocked may be included without departing from the scope of the present invention.

  The phenolic hydroxyl group-containing monomer and the C20-60 hydrocarbon group-containing monomer may be contained in at least one monomer of the dibasic acid compound and the diamine compound. The dibasic acid compound and the diamine compound Both of these groups may contain these groups, respectively. For example, when two kinds of dibasic acid compounds R1-1 and R1-2 and two kinds of diamine compounds R2-1 and R2-2 are used, -CO-R1-1-CO-NH-R2-1-NH-, -CO-R1-1-CO-NH-R2-2-NH-, -CO-R1-2-CO-NH-R2-1-NH-, -CO-R1-2-CO-NH-R2-2 A —NH— structural unit may be included.

<Polybasic acid monomer (m1)>
[Polybasic acid compound having phenolic hydroxyl group]
The polybasic acid compound having a phenolic hydroxyl group used in the present invention is not particularly limited, but hydroxyisophthalic acid such as 2-hydroxyisophthalic acid, 4-hydroxyisophthalic acid and 5-hydroxyisophthalic acid, 2,5-dihydroxyisophthalic acid. , 2,4-dihydroxyisophthalic acid, dihydroxyisophthalic acid such as 4,6-dihydroxyisophthalic acid, 2-hydroxyterephthalic acid, 2,3-dihydroxyterephthalic acid, dihydroxyterephthalic acid such as 2,6-dihydroxyterephthalic acid, 4 -Hydroxyphthalic acid such as hydroxyphthalic acid and 3-hydroxyphthalic acid, dihydroxy such as 3,4-dihydroxyphthalic acid, 3,5-dihydroxyphthalic acid, 4,5-dihydroxyphthalic acid and 3,6-dihydroxyphthalic acid Such as phthalic acid It is. Further, these acid anhydrides and ester derivatives such as polybasic acid methyl ester are also included. The only difference is that a dehydration reaction occurs in the case of a free polybasic acid or an acid anhydride and a corresponding dealcoholization reaction occurs in the case of an ester derivative. Of these, 5-hydroxyisophthalic acid is preferable from the viewpoints of copolymerizability, availability, and the like. In addition, when 5-hydroxyisophthalic acid is used, R1 in the general formula (1), that is, a divalent linking group which is a polybasic acid compound residue means that two carboxyl groups are removed from the 5-hydroxyisophthalic acid. It is the part that

[Polybasic Acid Compound Containing C20-60 Hydrocarbon Group]
As the polybasic acid compound containing a C20-60 hydrocarbon group used in the present invention, as a suitable example, a monobasic unsaturated fatty acid having one or more double or triple bonds having 10 to 24 carbon atoms is reacted. A polybasic acid compound having a cyclic structure of 5 to 10 carbon atoms obtained by the above can be mentioned. An example of the reaction is the Diels-Alder reaction. For example, natural fatty acids such as soybean oil fatty acid, tall oil fatty acid, and rapeseed oil fatty acid, and dimers obtained by carrying out a Diels-Alder reaction using oleic acid, linoleic acid, linolenic acid, erucic acid, etc., which are purified of these as raw materials. A polybasic acid compound containing a modified fatty acid (dimer acid) is preferably used.
The number of cyclic structures may be one or two, and in the case of two, the two rings may be independent or may be continuous. Examples of the cyclic structure include a saturated alicyclic structure, an unsaturated alicyclic structure, and an aromatic ring. Although the carboxyl group can be directly bonded to the cyclic structure, it is preferable that the carboxyl group is bonded to the cyclic structure through an aliphatic chain from the viewpoint of improving solubility and flexibility. The carbon number between the carboxyl group and the cyclic structure is preferably 2 to 25. Further, the polybasic acid compound containing a C20-60 hydrocarbon group may have a chain alkyl group having a high degree of freedom and hydrophobicity as a portion other than the cyclic structure from the viewpoint of improving solubility, improving flexibility and the like. preferable. It is preferable that there are two or more alkyl groups for one cyclic structure. The alkyl group preferably has 2 to 25 carbon atoms.

  The polybasic acid compound containing a C20-60 hydrocarbon group is usually composed mainly of a monomer containing a dimer derived from dimer acid (dimerized fatty acid) as a residue, and in addition to the raw material fatty acid or ternary compound. It is obtained as a composition of fatty acids that has been polymerized or more. Among them, the content of the monomer containing the dimer derived from dimer acid (dimerized fatty acid) as a residue in 70% by mass or more of 100% by mass of the C20-60 hydrocarbon group-containing monomer, It is preferably 95% by mass or more. Further, those obtained by hydrogenating (hydrogenating) the dimer to reduce the degree of unsaturation are particularly preferably used from the viewpoint of oxidation resistance (particularly coloring in a high temperature range) and suppression of gelation during synthesis. As the polybasic acid compound having a C20-60 hydrocarbon group, a monomer (polybasic acid compound) containing a dimer derived from a monobasic unsaturated fatty acid having 10 to 24 carbon atoms as a residue can be used. preferable. Further, as a part of the polybasic acid compound having a C20-60 hydrocarbon group, a monomer containing a trimer, which is a tricarboxylic acid, derived from a monobasic unsaturated fatty acid having 10 to 24 carbon atoms as a residue is used. It is preferable.

  The polybasic acid compound having a C20-60 hydrocarbon group can be obtained by a known reaction, but a commercially available product can also be used. Examples of commercially available products include, for example, "Pripol 1004", "Pripol 1006", "Pripol 1009", "Pripol 1013", "Pripol 1015", "Pripol 1017", "Pripol 1022", and "Pripol 102" manufactured by Croda Japan. 1025 "," Pripol 1040 "and" Enpol 1008 "," Empol 1012 "," Empol 1016 "," Empol 1026 "," Empol 1028 "," Empol 1043 "," Empol 1061 ", and" Empol 1061 "manufactured by BASF Japan Ltd. Enpol 1062 "and the like. These polybasic acid compounds can be used alone or in combination.

[Other polybasic acid compounds]
The polybasic acid compound other than the polybasic acid compound having a phenolic hydroxyl group and the C20-60 hydrocarbon group is not particularly limited as long as it does not depart from the gist of the present invention, but a dibasic acid compound or Trifunctional or more polybasic acid compounds can be mentioned. Examples of the dibasic acid compound include phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, benzophenone-4,4'-dicarboxylic acid and 4,4'-biphenyldicarboxylic acid. Aromatic dibasic acids such as, oxalic acid, malonic acid, methylmalonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, malic acid, tartaric acid, thiomalic acid, pimelic acid, suberic acid, azelaic acid , Aliphatic dibasic acids such as sebacic acid, dodecanedioic acid, hexadecanedioic acid and diglycolic acid, fats such as 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and 1,3-cyclopentanedicarboxylic acid A cyclic dibasic acid etc. are mentioned. Examples of trifunctional or higher polybasic acid compounds include trimellitic acid, hydrogenated trimellitic acid, pyromellitic acid, hydrogenated pyromellitic acid, and 1,4,5,8-naphthalenetetracarboxylic acid.

  These polybasic acid compounds may be used alone or in combination for the polybasic acid compound having a phenolic hydroxyl group and the polybasic acid compound having a C20-60 hydrocarbon group. Good. Among them, isophthalic acid and 1,4-cyclohexanedicarboxylic acid can be preferably used because a tough polyamide having more excellent heat resistance can be obtained. Further, by using a trifunctional or higher functional compound, a branched structure can be introduced into the polyamide to increase the molecular weight, and the cohesive force of the obtained polyamide can be increased. As a result, heat resistance can be improved without adversely affecting flexibility.

   Furthermore, monofunctional ones can be used in the present invention. By using a monofunctional one, it is possible to reduce the carboxyl groups and amino groups that can serve as terminal functional groups of the polyamide, and to control the molecular weight of the obtained polyamide. As a result, the temporal stability of the polyamide resin can be improved. Examples of the monobasic acid compound include benzoic acid, 4-hydroxybenzoic acid and 2-ethylhexanoic acid.

<Polyamine monomer (m2)>
The polyamine compound having a phenolic hydroxyl group is not particularly limited, and examples thereof include polyamines represented by the following general formula (2).

In the formula, R ₃ represents a direct bond or a group consisting of carbon, hydrogen, oxygen, nitrogen, sulfur, or halogen, for example, a divalent hydrocarbon group having 1 to 30 carbon atoms or a part of hydrogen by a halogen atom. or a divalent hydrocarbon group having 1 to 30 carbon atoms in which all are _{substituted, - (C = O) -} , - SO 2 -, - O -, - S -, - NH- (C = O) - ,-(C = O) -O-, a group represented by the following general formula (3) and a group represented by the following general formula (4). In the formula, r and s each independently represent an integer of 1 to 20, and R4 represents a hydrogen atom or a methyl group.

R ₃ is preferably a direct bond.

When the compound of the general formula (2) is used, R ₂ in the general formula (1), that is, a divalent linking group which is a polyamine compound residue means two amino groups from the compound of the general formula (2). It is the part except.

[Polyamine compound containing C20-60 hydrocarbon group]
Examples of the polyamine compound containing a C20-60 hydrocarbon group include compounds obtained by converting the carboxyl group of the aforementioned polybasic acid compound having a C20-60 hydrocarbon group into an amino group, and examples of commercially available products include, for example, Croda. Examples include "Puriamine 1071", "Puriamine 1073", "Puriamine 1074", and "Puriamine 1075" manufactured by Japan, and "Versamine 551" manufactured by BASF Japan. These polyamine compounds can be used alone or in combination. Among them, the use of “preamine 1071” containing about 20 to 25% by mass of a triamine component which is a trimer can improve the cohesive force of polyamide and can be preferably used from the viewpoint of improving heat resistance. From the viewpoint of the production stability of the polyamide, the total amount of the triamine triamine and the trimer tricarboxylic acid is 0.1 to 20 mass in 100 mass% of all the monomers used for forming the polyamide. %, And more preferably 1 to 10% by mass.

[Other polyamine compounds]
Next, polyamine compounds other than the polyamine compound having a phenolic hydroxyl group and the polyamine compound having a C20-60 hydrocarbon group are not particularly limited as long as they do not depart from the gist of the present invention, but include a diamine compound and a triamine compound. To be As the diamine compound, 1,4-diaminobenzene, 1,3-diaminobenzene, 1,2-diaminobenzene, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 2,6 -Diaminotoluene, 2,4-diaminotoluene, 3,4-diaminotoluene, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 4,4'-diamino-1, 2-diphenylethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylsulfone, 3,3′-diaminobenzophenone, 3,3 ′ -Aromatic diamines such as diaminodiphenyl sulfone, ethylenediamine, 1, Aliphatic polyamines such as 3-propanediamine, 1,4-butanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,9-nonanediamine, 1,12-dodecamethylenediamine and metaxylenediamine, isophorone Examples thereof include alicyclic diamines such as diamine, norbornanediamine, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4′-diaminodicyclohexylmethane and piperazine. Examples of trifunctional or higher polyamine compounds include 1,2,4-triaminobenzene and 3,4,4′-triaminodiphenyl ether. In addition, if an amino group is not directly bonded even if it has an aromatic ring, it is classified as aliphatic or the like.

  These polyamine compounds may be used alone or in combination with a polyamine having a phenolic hydroxyl group or a polyamine having a C20-60 hydrocarbon group. Among them, isophoronediamine and norbornanediamine can be preferably used because a tough polyamide having more excellent heat resistance can be obtained.

  Further, by using a trifunctional or higher functional compound, a branched structure can be introduced into the polyamide to increase the molecular weight, and the cohesive force of the obtained polyamide can be increased. As a result, adhesiveness, heat resistance, etc. can be improved.

  Furthermore, monofunctional ones can be used in the present invention. By using a monofunctional one, it is possible to reduce the carboxyl groups and amino groups that can serve as terminal functional groups of the polyamide, and to control the molecular weight of the obtained polyamide. As a result, the temporal stability of the polyamide resin can be improved. On the other hand, when the carboxyl group or amino group, which can be a terminal functional group, is not reduced by a monofunctional compound, a phenol group and a carboxyl group and / or an amino group are mixed in the resin, which may react with the phenolic hydroxyl group. When the compound (B) having three or more functional groups is used in combination, the processability and the adhesiveness can be improved by utilizing the difference in reactivity, which is desirable. Examples of monofunctional amine compounds include aniline, 4-aminophenol, and 2-ethylhexylamine.

  The phenolic hydroxyl group-containing polyamide (A-1) of the present invention is a polybasic monomer (m1) or a polyamine monomer (m2) depending on the adhesiveness, heat resistance, and other properties to be improved. ) Can be appropriately selected and obtained.

  The polyamide (A-1) obtained by polymerization may be one obtained by randomly polymerizing a component having a phenolic hydroxyl group and a component having a C20-60 hydrocarbon group, or may be a block polymer. It may be. That is, a mixture of plural kinds of polybasic acid monomer compounds and one kind of polyamine compound may be polymerized, or a mixture of plural kinds of polybasic acid compounds and a kind of polyamine compound may be polymerized. Good, one kind of polybasic acid compound may be polymerized with a mixture of a plurality of kinds of polyamine compounds, or a functional group remaining at the terminal after polymerization of one kind of polybasic acid compound and one kind of polyamine compound Depending on the groups, other polybasic acid compounds or other polyamine compounds may be polymerized.

  The polyamide (A-1) of the present invention includes all monomers used for formation, that is, a polybasic acid monomer (m1), a polyamine monomer (m2), and a monobasic acid used as necessary. In a total of 100 mol of the monofunctional amine compounds, a compound containing a C20-60 hydrocarbon group is preferably contained in an amount of 40 to 98 mol%, more preferably 45 to 96 mol%, still more preferably 50 to 94 mol%. . On the other hand, if it is used outside the range, if the ratio is small, sufficient flexibility may not be obtained. Further, if the proportion used is too large, the heat resistance and the thermal conductivity may decrease.

A method for calculating the number of moles of the monomer containing a C20-60 hydrocarbon group will be described. First, the molecular weight (M) of a monomer containing a C20-60 hydrocarbon group is determined by the following formula.
M = (56.11 × F × 1000) / E
F: Number of functional groups of monomer containing C20-60 hydrocarbon group E: Acid value of monomer containing C20-60 hydrocarbon group (mgKOH / g)
Then, the mass of the compound containing a C20-60 hydrocarbon group subjected to polymerization is divided by the molecular weight (M) to obtain the number of moles of the compound containing a C20-60 hydrocarbon group subjected to polymerization. Similarly, the number of moles of each of the monomers subjected to the polymerization is determined, and these are summed to determine the number of moles of all the monomers subjected to the polymerization. Then, by dividing the number of moles of the compound containing a C20-60 hydrocarbon group by the number of moles of all the monomers, the proportion (mol%) occupied by the compound containing a C20-60 hydrocarbon group can be obtained.

<< Polyamide (A-3) >>
Polyamide (A-3) is a polyamide obtained by mixing polyamide (a-1) and (a-2). The polyamide (a-1) is obtained by polymerizing a polybasic acid monomer (m3) and a polyamine monomer (m4), has a phenolic hydroxyl group in its side chain, and has a C20-60 hydrocarbon group. Does not have. It suffices that the above conditions are satisfied, and other polybasic acid monomers and polyamine monomers can be appropriately used. That is, the polybasic acid monomer (m3) is a group consisting of a polybasic acid compound having a phenolic hydroxyl group and another polybasic acid compound (however, excluding a polybasic acid compound containing a C20-60 hydrocarbon group). The polyamine monomer (m4) is selected from at least one selected from the group consisting of polyamine compounds having a phenolic hydroxyl group and other polyamine compounds (excluding polyamine compounds having a C20-60 hydrocarbon group). It may be selected from at least one so that the polymer contains a phenolic hydroxyl group. At least one of the polybasic acid monomer (m3) and the polyamine monomer (m4) has a phenolic hydroxyl group. You may adjust a suitable molecular weight, introducing a branched structure by combining a bivalent monomer and a trivalent or more monomer. It is also possible to use a monovalent monomer to keep the molecular weight appropriate. That is, the polyamide (a-1) is a polyamide having a phenolic hydroxyl group in its side chain but not having a C20-60 hydrocarbon group.

  On the other hand, the polybasic acid monomer (m5) is a group consisting of a polybasic acid compound containing a C20-60 hydrocarbon group and other polybasic acid compounds (however, excluding the polybasic acid compound having a phenolic hydroxyl group). The polyamine monomer (m6) is at least one selected from the group consisting of a polyamine compound containing a C20-60 hydrocarbon group and another polyamine compound (excluding a polyamine compound having a phenolic hydroxyl group). At least one of the polybasic acid monomer (m5) and the polyamine monomer (m6) contains a C20-60 hydrocarbon group. That is, the polyamide (a-2) is a polyamide having a C20-60 hydrocarbon group, but having no phenolic hydroxyl group in the side chain.

That is, the polyamide (A-3) has a phenolic hydroxyl group in its side chain, but does not have a C20-60 hydrocarbon group (a-1) and has a C20-60 hydrocarbon group, but has a side chain. It is a mixture with the polyamide (a-2) having no phenolic hydroxyl group.
The trifunctional or higher functional compound (B) capable of reacting with a phenolic hydroxyl group, which will be described later, is capable of reacting with the phenolic hydroxyl group and, in many cases, with at least one of a carboxyl group and an amino group. When thermosetting a thermoplastic resin composition containing a mixture (A-3) and a trifunctional or higher functional compound (B) capable of reacting with a phenolic hydroxyl group, a trifunctional or higher functional compound capable of reacting with a phenolic hydroxyl group ( When a compound capable of reacting with at least one of a carboxyl group and an amino group is used as B), the polyamide (a-1) containing a phenolic hydroxyl group in the mixture (A-3) and the polyamide having a C20-60 hydrocarbon group are used. The terminal carboxyl group and terminal amino group possessed by (a-2) can also be utilized for the thermosetting reaction.

  The mixing ratio of the phenolic hydroxyl group-containing polyamide (a-1) and the C20-60 hydrocarbon group-containing polyamide (a-2) is appropriately adjusted depending on the phenolic hydroxyl group value and the molecular weight of (a-1). It is possible, but it is preferable that the phenolic hydroxyl group-containing polyamide: C20-60 hydrocarbon group-containing polyamide = 5: 95-80: 20 (mass ratio), and 10: 90-50: 50. Is preferred.

  The "mixture" and "mixing" of the polyamide (A-3) are intended to include the following cases. That is, when a mixture is preliminarily obtained from the polyamide (a-1) and the polyamide (a-2), and a trifunctional or higher functional compound (B) capable of reacting with a phenolic hydroxyl group described later is blended, or the polyamide is used. When (a-1) is blended with the polyamide (a-2) and a trifunctional or higher functional compound (B) capable of reacting with a phenolic hydroxyl group described later, or with the polyamide (a-1) and a phenolic compound described later. It is intended to include the case where the polyamide (a-2) is blended after blending the trifunctional or higher functional compound (B) capable of reacting with a hydroxyl group, and vice versa.

  Examples of the polybasic acid monomer (m3) include polybasic acid monomers (m4) other than the polybasic acid compound containing a C20-60 hydrocarbon group. Further, a monobasic compound can be used together. Examples of the polyamine monomer (m4) include polyamine monomers (m2) other than the polyamine compound having a C20-60 hydrocarbon group. Further, a monofunctional amine compound can be used together.

 Examples of the polybasic acid monomer (m5) include polybasic acid monomers (m1) other than the polybasic acid compound having a phenolic hydroxyl group. Further, a monobasic compound can be used together. Examples of the polyamine monomer (m6) include polyamine monomers (m2) other than the polyamine compound having a phenolic hydroxyl group. Further, a monofunctional amine compound can be used together.

  The polyamide (A-3) of the present invention comprises all monomers used for formation, namely, polybasic acid monomer (m3), polyamine monomer (m4), polybasic acid monomer (m5), It is preferable that 40 to 98 mol% of a compound containing a C20 to 60 hydrocarbon group is contained in 100 mol of the total of 100 mol of the polyamine monomer (m6) and the monobasic acid or monofunctional amine compound used as necessary, and 45 to The content is more preferably 96 mol%, further preferably 50 to 94 mol%.

<Specifications of Phenolic Hydroxyl Group-Containing Polyamide (A)>
Next, the specifications (phenolic hydroxyl value, mass average molecular weight, glass transition temperature) of the phenolic hydroxyl group-containing polyamide (A) of the present invention will be described.

  The phenolic hydroxyl group-containing polyamide (A) of the present invention may have a carboxyl group or an amino group at the terminal and may have a functional group at the terminal as long as the polyamide has a phenolic hydroxyl group in the side chain. You don't have to. The amount of the phenolic hydroxyl group contained in the side chain of the polyamide can be appropriately adjusted depending on the type and amount of the trifunctional or higher functional compound (B) capable of reacting with the phenolic hydroxyl group.

[Phenolic hydroxyl value]
Specifically, the phenolic hydroxyl value of the phenolic hydroxyl group-containing polyamide (A) of the present invention is preferably 1 to 60 mgKOH / g, more preferably 3 to 50 mgKOH / g, and further preferably 5 to 45 mgKOH / g. It is g. By using a polyamide having a phenolic hydroxyl value of 1 mgKOH / g or more, a dense crosslinked structure can be formed and the resistance of the coating film after curing can be improved. Further, by using a polyamide having a phenolic hydroxyl value of 60 mgKOH / g or less, a cured coating film having good hardness, durability and flexibility can be obtained. Further, when a polyamide having a phenolic hydroxyl value in the range of 1 to 60 mgKOH / g is used in the range of close to 1 mgKOH / g, the adhesiveness and flexibility of the resulting coating film are improved, while it is close to 60 mgKOH / g. When a polyamide in the range is used, the number of cross-linking points increases, so that the heat resistance of the finally obtained coating film improves. Thus, in the present invention, the phenolic hydroxyl value of the phenolic hydroxyl group-containing polyamide (A) can be adjusted according to the purpose within the range of 1 to 60 mgKOH / g.

  In the case of (i), the above-mentioned phenolic hydroxyl value can be adjusted by the charging ratio (polymerization composition) of the monomer having a phenolic hydroxyl group among the monomers. Further, in the case of (ii), it can be adjusted by the ratio of the monomer having a phenolic hydroxyl group in the total monomers of the polyamides (a-1) and (a-2).

  In the case of the mixture (A-3) of the phenolic hydroxyl group-containing polyamide (A), the phenolic hydroxyl group value of the mixture is the phenolic hydroxyl group value of the phenolic hydroxyl group-containing polyamide (A).

[Mass average molecular weight]
Among the phenolic hydroxyl group-containing polyamides (A), the mass average molecular weight of the polyamide (A-1) is 10,000 to 500,000 from the viewpoints of handleability, flexibility when formed into a thermosetting product, and heat resistance. It is preferably 13,000 to 450,000, more preferably 15,000 to 400,000. Of the phenolic hydroxyl group-containing polyamide (A), the mass average molecular weight of the polyamide (a-1) is preferably 500 to 30,000, from the viewpoint of solubility in a general-purpose solvent described later, 1000 to 20, 000 is more preferable, and 1,000 to 10,000 is still more preferable. Further, among the phenolic hydroxyl group-containing polyamides (A), polyamides (a
The mass average molecular weight of -2) is preferably in the same range as in the case of the polyamide (A-1).

[Glass transition temperature of phenolic hydroxyl group-containing polyamide (A)]
The glass transition temperature of the phenolic hydroxyl group-containing polyamide (A) of the present invention is preferably −40 ° C. to 60 ° C., more preferably −30 ° C. to 50 ° C. By adjusting the glass transition temperature of the phenolic hydroxyl group-containing polyamide (A) in the range of -40 ° C to 60 ° C, excellent heat resistance can be exhibited, and further flexibility is imparted, and heat cycle resistance is provided. Can be improved.

  The glass transition temperature can be adjusted by appropriately setting the ratio of the polybasic acid compound having a C20-60 hydrocarbon group or the polyamine compound having a C20-60 hydrocarbon group. For example, by increasing the compounding ratio of the polybasic acid compound having a C20-60 hydrocarbon group or the polyamine compound having a C20-60 hydrocarbon group, the concentration of the amide bond having a high water absorption rate can be lowered and the dimerized fatty acid can be obtained. The glass transition temperature can be adjusted within a range close to −40 ° C. because it can impart a peculiar softness and flexibility.

  In the case of the mixture (A-3) of the phenolic hydroxyl group-containing polyamide (A), the glass transition temperature of the mixture is the glass transition temperature of the phenolic hydroxyl group-containing polyamide (A).

[Phenolic hydroxyl group-containing polyamide (A) soluble in organic solvent]
The phenolic hydroxyl group-containing polyamide (A) of the present invention is widely soluble in a versatile organic solvent. Soluble means that 5 parts by mass or more is dissolved at 25 ° C. in 95 parts by mass of a mixed solvent of general-purpose solvents such as a hydrocarbon solvent, an alcohol solvent, a ketone solvent and an ester solvent. Say. In particular, it is preferable to dissolve 5 parts by mass or more at 95 ° C. in 95 parts by mass of a mixed solvent of toluene / isopropanol = 50/50 (mass ratio). Examples of the hydrocarbon solvent include benzene, toluene, ethylbenzene, xylene, cyclohexane and hexane. Examples of the alcohol solvent include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol, tert-butanol and the like. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of the ester solvent include methyl acetate, ethyl acetate, propyl acetate and butyl acetate.

<Synthesis of Phenolic Hydroxyl Group-Containing Polyamide (A)>
Next, a method for synthesizing the phenolic hydroxyl group-containing polyamide (A) of the present invention will be described. Polymerization conditions of the phenolic hydroxyl group-containing polyamide (A) used in the present invention are not particularly limited, and known conditions such as melt polymerization, interfacial polymerization, solution polymerization, bulk polymerization, solid phase polymerization, and a combination of these methods are known. Can be used. Generally, industrially, the reaction is carried out at 150 to 300 ° C. for about 1 to 24 hours in the presence or absence of a catalyst. In order to accelerate the dehydration or dealcoholization reaction and avoid the coloring and decomposition reaction due to high temperature, it is preferable to carry out the reaction at 180 to 270 ° C. under reduced pressure below atmospheric pressure.

In addition, polyester may be used in combination for the purpose of increasing the solubility in an organic solvent and increasing the flexibility of the cured product. The term “combined use” as used herein means not only the mixture of polyamide and polyester, but also the polyester polyamide in which a amide component and an ester bond are mixed in the presence of a polyol represented by a diol component when synthesizing the polyamide. is there.
However, since the ester bond is more easily hydrolyzed than the amide bond, it is necessary in the present invention that the polyamide is the main component. That is, it is important that the ester bond is 0 to 20 mol%, preferably 0 to 10 mol% in the total 100 mol% of the amide bond and the ester bond.

  When synthesizing a phenolic hydroxyl group-containing polyamide (A-1), for example, a nitrogen-filled flask is provided with a polybasic acid compound having a phenolic hydroxyl group and / or a polyamine compound having a phenolic hydroxyl group, C20-60 carbonized. A polybasic acid compound having a hydrogen group or / and a polyamine compound having a C20-60 hydrocarbon group and a predetermined amount of ion-exchanged water are charged, and the mixture is uniformly dissolved or dispersed by heating and stirring at 20 to 100 ° C. Then, the temperature is gradually raised to 230 ° C. while removing the ion-exchanged water and the water generated by the reaction, and when the temperature reaches 230 ° C., the pressure is reduced to about 15 mmHg and the temperature is maintained for about 1 hour. -1) can be obtained. In addition, when the polybasic acid compound and the polyamine compound are mixed, a salt is formed to easily solidify. Since the salt formed by mixing the two in the presence of ion-exchanged water is dissolved or dispersed in the ion-exchanged water, it is preferable to use the ion-exchanged water from the viewpoint of safety and the like.

  Specific examples of catalysts that can be used for obtaining the phenolic hydroxyl group-containing polyamide (A-1) include, for example, phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, polyphosphoric acid, and alkali metal salts thereof. , Inorganic phosphorus compounds such as alkaline earth metal salts, phosphite esters such as triphenyl phosphite and diphenyl phosphite, titanium-based catalysts such as tetrabutyl orthotitanate and tetraisopropyl orthotitanate, dibutyltin oxide, dibutyltin. Examples thereof include tin-based catalysts such as laurate and monobutylhydroxytin oxide, and zirconium-based catalysts such as tetrabutoxyzirconium, zirconium acetate and zirconium octylate.

  These may be used as a mixture of two or more kinds. Further, even if these catalysts are contained in the phenolic hydroxyl group-containing polyamide (A), there is no problem in carrying out the present invention.

  The by-product is a catalyst of a decomposition product of the catalyst used, an oxide of the decomposition product or a modified product thereof, and a salt of an inorganic salt such as an amide compound such as an oligomer. ) May be contained.

<Trifunctional or higher functional compound (B) capable of reacting with phenolic hydroxyl group>
The thermosetting resin composition of the present invention contains the above-mentioned phenolic hydroxyl group-containing polyamide (A) and a trifunctional or higher functional compound (B) capable of reacting with the phenolic hydroxyl group. The trifunctional or higher functional compound (B) capable of reacting with the phenolic hydroxyl group will be described. The thermosetting resin composition of the present invention uses the compound (B) as a curing agent for the above-mentioned phenolic hydroxyl group-containing polyamide (A). In addition to the trifunctional or higher functional compound (B), a bifunctional compound (D) capable of reacting with a phenolic hydroxyl group [hereinafter, also referred to as “compound (D)”] is within the scope of the present invention. Can be added. When the compound (D) is added, it is preferably 100 parts by mass or less, and more preferably 60 parts by mass or less with respect to 100 parts by mass of the compound (B) from the viewpoint of effectively increasing the crosslinking density. .

[Epoxy group-containing compound]
The trifunctional or more functional epoxy group-containing compound that can be used as the compound (B) in the present invention is not particularly limited as long as it is a compound having an epoxy group in the molecule, and examples thereof include glycidyl ether type epoxy. An epoxy resin such as a resin, a glycidylamine type epoxy resin, a glycidyl ester type epoxy resin, or a cycloaliphatic (alicyclic) epoxy resin can be used. Particularly, since the epoxy group-containing compound having a viscosity of 10 to 1,000,000 mPa · S at 25 ° C. has good compatibility with the polyamide (A), a heat conductive sheet having excellent thermal conductivity and durability can be obtained. Very favorable in terms.

  Examples of the glycidyl ether type epoxy resin include cresol novolac type epoxy resin, phenol novolac type epoxy resin, and tetrakis (glycidyloxyphenyl) ethane. Examples of the glycidyl amine type epoxy resin include tetraglycidyl diaminodiphenylmethane and tetraglycidyl metaxylylenediamine. From the viewpoint of high adhesiveness and heat resistance, it is preferable to use tetrakis (glycidyloxyphenyl) ethane or tetraglycidyldiaminodiphenylmethane as the epoxy group-containing compound.

  Examples of the epoxy group-containing compound that can be used as the compound (D) include glycidyl ether type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and dicyclopentadiene type epoxy resin. Examples of the glycidyl ester type epoxy resin include diglycidyl phthalate, diglycidyl hexahydrophthalate, diglycidyl tetrahydrophthalate, and the like. Examples of the cycloaliphatic (alicyclic) epoxy resin include 3 ', 4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate. As the epoxy group-containing compound, the compound (B) can be used alone or in combination of two or more kinds, or the compound (B) can be used in combination with the compound (D).

[Isocyanate compound]
The isocyanate group-containing compound that can be used as the compound (B) is not particularly limited as long as it is a compound having three or more isocyanate groups in the molecule. The isocyanate group may be either blocked with a blocking agent or not blocked, but is preferably blocked with a blocking agent.

  The isocyanate group-containing compound that can be used as the bifunctional compound (D) capable of reacting with the phenolic hydroxyl group is not particularly limited, but, for example, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6- Examples thereof include aromatic diisocyanates such as tolylene diisocyanate, aliphatic diisocyanates such as hexamethylene diisocyanate, and alicyclic diisocyanates such as isophorone diisocyanate.

  The isocyanate group-containing compound that can be used as the trifunctional or higher functional compound (B) capable of reacting with a phenolic hydroxyl group is not particularly limited, and examples thereof include the trimethylolpropane adduct of diisocyanate described above and burette reacted with water. And a trimer having an isocyanurate ring.

  The blocked isocyanate compound is not particularly limited as long as it is a blocked isocyanate group-containing compound in which the isocyanate group in the isocyanate group-containing compound is protected by ε-caprolactam, MEK oxime or the like. Specific examples thereof include those in which the isocyanate group of the isocyanate group-containing compound is blocked with ε-caprolactam, MEK oxime, cyclohexanone oxime, pyrazole, phenol and the like. Particularly, the hexamethylene diisocyanate trimer having an isocyanurate ring and blocked with MEK oxime or pyrazole is particularly preferable because it has excellent storage stability and heat resistance when used in the present invention.

[Carbodiimide group-containing compound]
Examples of the carbodiimide group-containing compound that can be used as the trifunctional or higher functional compound (B) capable of reacting with the phenolic hydroxyl group include the carbodilite series manufactured by Nisshinbo Industries. Among them, carbodilite V-01, 03, 05, 07, 09 is preferable because it has excellent compatibility with an organic solvent.

[Metal chelate compound]
Examples of the metal chelate compound that can be used as the trifunctional or higher functional compound (B) capable of reacting with the phenolic hydroxyl group include an aluminum chelate compound, a titanium chelate compound, and a zirconium chelate compound. The central metal is iron, cobalt, or indium. Since various metals such as the above can form a chelate bond, they are not particularly limited. The number of functional groups of the metal chelate and the metal alkoxide and the metal acylate described later is calculated as the valence of the central metal, and trifunctional or more, that is, those having a valence of the central metal of 3 or more are compounds (
It can be used as B).

  Typical examples of the aluminum chelate compound used in the present invention include aluminum acetylacetonate and aluminum ethylacetoacetate.

  Typical examples of the titanium chelate compound include titanium acetylacetonate, titanium ethylacetoacetate, titanium octylene glycolate, titanium lactate, titanium triethanolaminate, and polytitanium acetylacetylacetonate.

  Typical examples of the zirconium chelate compound include zirconium acetylacetonate, zirconium ethylacetylacetonate, zirconium lactate ammonium salt, and the like.

[Metal alkoxide]
Examples of the metal alkoxide compound include an aluminum alkoxide compound, a titanium alkoxide compound, and a zirconium alkoxide compound. However, since the central metal can form an alkoxide bond with various metals such as iron, cobalt, and indium, it is not particularly limited. Absent.

  Typical examples of the aluminum alkoxide compound include aluminum isopropylate, aluminum butyrate, and aluminum ethylate.

  Representative examples of the titanium alkoxide compound include isopropyl titanate, normal butyl titanate, butyl titanate dimer, tetraoctyl titanate, tertiary amyl titanate, tertiary butyl titanate, and tetrastearyl titanate.

  Typical examples of the zirconium alkoxide compound include normal propyl zirconate and normal butyl zirconate.

[Metal Acylate]
Examples of the metal acylate compound include an aluminum acylate compound, a titanium acylate compound, and a zirconium acylate compound, but are not particularly limited because various metals such as iron, cobalt, and indium as the central metal can form an alkoxide bond. Not something.

  The tri- or higher functional compound (B) contains not only the same functional groups of three or more functional groups in one molecule, but also the functional groups of three or more functional groups in total. For example, a mixture of chelate, alkoxide and acylate in one molecule can be preferably used.

  In the present invention, the compound (B) may be used alone or in combination of two or more. When used in combination, when using polyamide (A) in which phenol groups and carboxyl groups and / or amino groups are mixed, synergistic effects such as improved adhesiveness are exhibited by utilizing the difference in reactivity of each. Therefore, it is desirable. Among them, "at least one selected from the group consisting of metal chelates, metal alkoxides, and metal acylates" and "trifunctional or higher functional epoxy group-containing compound" are significantly different in reactivity, and also different in the physical properties that can be improved. Therefore, a large synergistic effect can be expected, which is preferable. The amount of the compound (B) to be used may be determined in consideration of the use of the heat conductive sheet of the present invention and the like, and is not particularly limited, but it is based on 100 parts by mass of the phenolic hydroxyl group-containing polyamide (A). Therefore, it is preferable to add it in a ratio of 0.5 to 100 parts by mass, more preferably 1 to 80 parts by mass. By using the compound (B), the crosslink density of the heat conductive sheet of the present invention can be adjusted to an appropriate value, and therefore various physical properties of the thermoset product can be further improved.

  In the present invention, a compound capable of reacting with a phenolic hydroxyl group or a compound which can react with a carboxyl group or a compound capable of reacting with an amino group can be used in combination with the compound (B) although it is somewhat unclear. Examples of the compound capable of reacting with the carboxyl group include an aziridine compound, a β-hydroxyalkylamide group-containing compound, and dicyandiamide. Examples of the compound capable of reacting with the amino group include maleimide compounds.

  In particular, 2,2′-bishydroxymethylbutanol tris [3- (1-aziridinyl) propionate], when used in the present invention, can suppress the squeeze-out of a hot press, and can be heat-resistant while maintaining the flexibility of a cured product. Since it can improve the property, it is preferably used in the present invention.

  In the present invention, a compound that directly contributes to the curing reaction can be contained as a curing accelerator. Examples of the curing accelerator include phosphine compounds, phosphonium salts, imidazole compounds and tertiary amine compounds.

<Thermally conductive filler (C)>
In the present invention, the heat conductive filler (C) is a compound that imparts heat conductivity to the heat conductive sheet. The heat conductive filler (C) is specifically a metal oxide such as aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride or boron nitride. , Metal nitrides, hydrated metal compounds, crystalline silica, amorphous silica, silicon carbide and the like are preferable. Among these, aluminum oxide, aluminum nitride and boron nitride are more preferable, and boron nitride is particularly preferable from the viewpoint of heat resistance and thermal conductivity.

  The thermal conductive filler (C) preferably has an average particle diameter (D50) calculated by a laser diffraction scattering method of 0.1 to 250 μm, more preferably 0.5 to 100 μm. The particle shape may be any shape such as spherical, needle-like, flake-like, and dendritic.

  The heat conductive sheet of the present invention contains 30 to 90 mass% or more of the heat conductive filler (C) in the total 100 mass% of the polyamide (A) and the compound (B) heat conductive filler (C). Is more preferable, it is more preferable to contain 32 to 85% by mass, and it is further preferable to contain 35 to 75% by mass. From the viewpoint of the balance between thermal conductivity and adhesive properties and flexibility, the thermally conductive filler (C) is preferably used within the above range.

  The heat conductive sheet of the present invention is a hindered phenolic antioxidant, a phosphorus antioxidant, a sulfur antioxidant, an amine antioxidant, and a copper antioxidant from the viewpoint of preventing the oxidation of the resin. It may contain an antioxidant.

  Known compounds can be used as the hindered phenol antioxidant. These compounds can be used alone or in combination. Among such hindered phenolic antioxidants, bifunctional or higher functional phenols are preferable, and triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate] (IRGANOX245) is used. Semi-hindered type such as is preferable in that it is difficult to discolor.

The phosphorus-based antioxidant is at least one selected from inorganic and organic phosphorus-based antioxidants. Examples of the inorganic phosphorus antioxidant include hypophosphite such as sodium hypophosphite, phosphite, and the like.
As the organic phosphorus-based antioxidant, a commercially available phosphite-based organic phosphorus-based antioxidant can be used, but an organic phosphorus-containing compound that does not generate phosphoric acid by thermal decomposition is preferable. Known compounds can be used as the organic phosphorus-containing compound.

  Known compounds can be used as the amine-based antioxidant that can be used in the present invention. In addition, secondary arylamines can also be mentioned as amine-based antioxidants. By secondary arylamine is meant an amine compound containing two carbon radicals chemically bonded to a nitrogen atom, wherein at least one, and preferably both carbon radicals are aromatic.

  As the sulfur-based antioxidant that can be used in the present invention, known compounds can be used.

  The copper-based antioxidant that can be used in the present invention is a stabilizer containing a mixture of a copper salt and an alkali metal halide and / or an alkaline earth metal halide. Examples include, but are not limited to, stabilizers that include a mixture of copper (I) iodide and potassium iodide.

  The heat conductive sheet of the present invention is sandwiched between a heat generating element and a heat radiating material, and efficiently releases heat, thereby playing a role of preventing performance deterioration. The article for heat dissipation is used for electronic components such as integrated circuits, IC chips, hybrid packages, multi-modules, power transistors, and LED (light emitting diode) substrates.

  The heat conductive sheet of the present invention can be formed by coating and drying a heat conductive resin composition containing a solvent on a substrate, and heating or heating while applying pressure. Before heating is referred to as a precursor member or a precursor sheet. The heat conductive sheet may also be referred to as a heat conductive film.

The thermally conductive resin composition containing a solvent is preferably produced by stirring and mixing the polyamide (A), the compound (B), the thermally conductive filler (C), and the solvent.
A general stirring method can be used for stirring and mixing, and examples thereof include scandex, paint conditioner, sand mill, raker machine, medialess disperser, three-roll mill, bead mill, and the like. You can
The solvent here means a dispersion medium.

  After stirring and mixing, it is preferable to go through a defoaming step in order to remove air bubbles from the heat conductive resin composition. The defoaming method is not particularly limited, and a general method can be used, and examples thereof include vacuum defoaming and ultrasonic defoaming.

  If necessary, various conventional additives can be added to the heat conductive resin composition. As various additives, for example, a coupling agent for increasing the adhesion of the base material, a dispersant for increasing the dispersibility of the thermally conductive filler and the binder resin, an ion trapping agent for increasing the insulation reliability during moisture absorption, and leveling. Agents and the like. These may be used alone or in combination of two or more.

  The coating method is not particularly limited, and known methods can be used, for example, knife coating, die coating, lip coating, roll coating, curtain coating, bar coating, gravure coating, flexo coating, dip coating, spray coating. , Spin coating and the like. Also, the sheet can be made by pouring into a mold and casting.

  As the base material, for example, a plastic film such as a polyester film, a polyethylene film, a polypropylene film, a polyimide film, or a film obtained by subjecting the plastic film to release treatment (hereinafter referred to as a release film) can be used. Further, a metal such as aluminum, copper, stainless steel, beryllium copper or the like, or a foil of these alloys can be used as the substrate.

Next, another substrate is superposed on the surface of the heat conductive layer of the precursor sheet, and pressed under heat to enhance the heat conductivity of the precursor sheet to obtain a heat conductive sheet.
When a thermally conductive resin composition is applied to a release film and dried, another release film is overlaid on the surface of the heat conductive layer and pressed under heat to heat the release film between two release films. The heat conductive sheet can be isolated by obtaining the conductive sheet and peeling off the release film. Alternatively, the same heat conducting layer may be superposed on the surface of the heat conducting layer and pressed under heat to obtain a laminate of heat conducting sheets.

  The pressure press treatment is not particularly limited, and a known press treatment machine can be used. The temperature at the time of pressing can be appropriately selected, but if it is used as a thermosetting adhesive sheet, it is desirable to heat at a temperature at which the thermosetting reaction of the binder resin and the curing agent occurs or higher.

  The pressure at the time of pressing can be appropriately selected so that the thermally conductive inorganic particles come into contact with each other.

  It is also possible to obtain a molded product having high thermal conductivity by covering the heat source with a mold, pouring a thermally conductive resin composition containing no solvent into the gap, and molding under pressure.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the technical scope of the present invention is not limited thereto. Parts mean parts by mass.

<Measurement method of mass average molecular weight (MW)>
The Mw was measured by GPC (gel permeation chromatography) "GPC-101" manufactured by Showa Denko KK. GPC is a liquid chromatography in which a substance dissolved in a solvent (THF; tetrahydrofuran) is separated and quantified by the difference in its molecular size. In the measurement of the present invention, two "KF-805L" (Showa Denko KK: GPC column: 8 mm ID x 300 mm size) are connected in series to the column, and a sample concentration of 1 wt%, a flow rate of 1.0 ml / min, and a pressure are used. The determination was performed under conditions of 3.8 MPa and a column temperature of 40 ° C., and the weight average molecular weight (Mw) was determined in terms of polystyrene. For data analysis, a calibration curve, a molecular weight, and a peak area were calculated using the software built in the maker, and the mass average molecular weight was determined with a retention time of 17.9 to 30.0 minutes as an analysis target.

<Measurement of acid value>
About 1 g of a sample is accurately weighed in a ground-in stopper Erlenmeyer flask, and 100 mL of cyclohexanone solvent is added and dissolved. To this, phenolphthalein reagent solution is added as an indicator and kept for 30 seconds. Then, the solution is titrated with a 0.1N alcoholic potassium hydroxide solution until it turns pink. The acid value was calculated by the following formula (unit: mgKOH / g).
Acid value (mgKOH / g) = (5.611 × a × F) / S
However,
S: Amount of sample (g)
a: Consumption of 0.1N alcoholic potassium hydroxide solution (mL)
F: Strength of 0.1N alcoholic potassium hydroxide solution <Method for measuring phenolic hydroxyl group value>
The phenolic hydroxyl value is the amount of phenolic hydroxyl group contained in 1 g of the phenolic hydroxyl group-containing polyamide, and is the hydroxylation amount necessary for neutralizing acetic acid bound to the phenolic hydroxyl group when the phenolic hydroxyl group is acetylated. It is expressed by the amount of potassium (mg). The phenolic hydroxyl value was measured according to JIS K0070. In the present invention, when the phenolic hydroxyl value of the phenolic hydroxyl group-containing polyamide of the terminal carboxylic acid is calculated, the acid value is taken into consideration as shown in the following formula.
<Measurement of phenolic hydroxyl value>
About 1 g of a sample is accurately weighed in a ground-in stopper Erlenmeyer flask, and 100 mL of cyclohexanone solvent is added and dissolved. Further, exactly 5 mL of an acetylating agent (solution in which 25 g of acetic anhydride was dissolved in pyridine to make the volume 100 mL) was added, and the mixture was stirred for about 1 hour. To this, phenolphthalein reagent solution is added as an indicator, and this is continued for 30 seconds. Then titrate with 0.5N alcoholic potassium hydroxide solution until the solution appears pink.
The hydroxyl value was calculated by the following formula (unit: mgKOH / g).
Hydroxyl value (mgKOH / g) = [{(ba) × F × 28.05} / S] + D
However,
S: Amount of sample (g)
a: Consumption of 0.5N alcoholic potassium hydroxide solution (mL)
b: Consumption of blank 0.5N alcoholic potassium hydroxide solution (mL)
F: titer of 0.5N alcoholic potassium hydroxide solution D: acid value (mgKOH / g)

<Measurement of amine value>
About 1 g of a sample is accurately weighed in a ground-in stopper Erlenmeyer flask, and 100 mL of cyclohexanone solvent is added and dissolved. To this, add a few drops of an indicator prepared by mixing a solution prepared by dissolving 0.20 g of Methyl Orange in 50 mL of distilled water and a solution prepared by dissolving 0.28 g of Xylene Cyanol FF in 50 mL of methanol. Hold for seconds. Then titrate with 0.1N alcoholic hydrochloric acid solution until the solution appears blue gray. The amine value was calculated by the following formula (unit: mgKOH / g).
Acid value (mgKOH / g) = (5.611 × a × F) / S
However,
S: Amount of sample (g)
a: Consumption of 0.1N alcoholic hydrochloric acid solution (mL)
F: titer of 0.1N alcoholic hydrochloric acid solution

<Measurement of glass transition temperature>
About the polyamide (A) from which the solvent was dried and removed, "DSC-1" manufactured by METTLER TOLEDO was used, and a sample amount of about 5 mg was weighed in an aluminum standard container, and a temperature modulation amplitude ± 1 ° C and a temperature modulation cycle of 60 seconds. The glass transition temperature was determined from the differential heat curve of the reversible component by measuring the temperature from −80 to 200 ° C. under the condition of temperature rising rate of 2 ° C./min.

Synthesis Example 1
In a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, an inlet tube, and a thermometer, 198.4 parts (0.34 mol in terms of dibasic acid) of PRIPOL 1009 as a polybasic acid compound having 36 carbon atoms. , 119.7 parts (0.66 mol) of 5-hydroxyisophthalic acid (hereinafter, also referred to as 5-HIPA) as a polybasic acid compound having a phenolic hydroxyl group, and 504.1 parts of preamine 1074 as a polyamine compound having 36 carbon atoms. 100 parts of ion-exchanged water (0.94 mol in terms of diamine) was added, and the mixture was stirred until the temperature of heat generation became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant is added, and a mass average molecular weight of 27800, an acid value of 8.1 mgKOH / g, an amine value of 0.3 mgKOH / g, a phenolic hydroxyl value of 45 mgKOH / g, and a glass transition temperature of 20 ° C. Resin 1 was obtained. In addition, the monomer having a C20-60 hydrocarbon group is 66.2 mol% in 100 mol% of all the monomers used for the reaction.

Synthesis example 2
300.8 parts of Pripol 1009 as a polybasic acid compound having 36 carbon atoms (0.52 mol in terms of dibasic acid) was placed in a 4-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer. , 87.4 parts (0.48 mol) of 5-hydroxyisophthalic acid as a polybasic acid compound having a phenolic hydroxyl group, 504.1 parts of preamine 1074 as a polyamine compound having 36 carbon atoms (0.94 mol in terms of diamine), 100 parts of ion-exchanged water was charged, and the mixture was stirred until the exothermic temperature became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant was added, and a weight average molecular weight of 30,300, an acid value of 7.3 mgKOH / g, an amine value of 0.3 mgKOH / g, a phenolic hydroxyl value of 30.3 mgKOH / g, and a phenolic hydroxyl group having a glass transition temperature of 5 ° C. The containing polyamide resin 2 was obtained. In addition, in 100 mol% of all monomers used for the reaction, the amount of the monomer having a C20-60 hydrocarbon group is 75.3 mol%.

Synthesis example 3
425.2 parts of Pripol 1009 as a polybasic acid compound having 36 carbon atoms (0.74 mol in terms of dibasic acid) in a 4-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer. , 58.3 parts (0.27 mol) of 5-hydroxyisophthalic acid as a polybasic acid compound having a phenolic hydroxyl group, 523.9 parts of preamine 1074 as a polyamine compound having 36 carbon atoms (0.98 mol in terms of diamine), 100 parts of ion-exchanged water was charged, and the mixture was stirred until the exothermic temperature became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant was added, and a mass average molecular weight of 98,000, an acid value of 2.3 mgKOH / g, an amine value of 0.2 mgKOH / g, a phenolic hydroxyl value of 15 mgKOH / g, and a glass transition temperature of -15 ° C containing a phenolic hydroxyl group. Polyamide resin 3 was obtained. In addition, in 100 mol% of all the monomers used for the reaction, the amount of the monomer having a C20-60 hydrocarbon group was 86.6 mol%.

Synthesis example 4
A four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, an inlet tube, and a thermometer was used. As another polybasic acid compound, 184.93 parts (0.80 mol) of dodecanedioic acid and polyphenol having a phenolic hydroxyl group were used. Charge 35.88 parts (0.20 mol) of 5-hydroxyisophthalic acid as a basic acid compound, 515.66 parts of preamine 1074 (0.96 mol in terms of diamine) as a polyamine compound having 36 carbon atoms, and 100 parts of ion-exchanged water. The mixture was stirred until the exothermic temperature became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant is added, and a mass average molecular weight of 40,000, an acid value of 5.3 mgKOH / g, an amine value of 0.3 mgKOH / g, a phenolic hydroxyl value of 15 mgKOH / g, and a glass transition temperature of 25 ° C. and a phenolic hydroxyl group-containing polyamide. Resin 4 was obtained. In addition, the monomer having a C20-60 hydrocarbon group is 49.1 mol% in 100 mol% of all the monomers used in the reaction.

Synthesis example 5
455.2 parts of Pripol 1009 as a polybasic acid compound having 36 carbon atoms (0.79 mol in terms of dibasic acid) was placed in a 4-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer. , 38.8 parts (0.21 mol) of 5-hydroxyisophthalic acid as a polybasic acid compound having a phenolic hydroxyl group, 98.7 parts (0.58 mol) of isophoronediamine as another polyamine compound, a polyamine compound having 36 carbon atoms Then, 313.9 parts of preamine 1074 (0.39 mol in terms of diamine) and 100 parts of ion-exchanged water were charged and stirred until the temperature of heat generation became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant is added, and a weight average molecular weight of 45,000, an acid value of 4.9 mgKOH / g, an amine value of 0.3 mgKOH / g, a phenolic hydroxyl group value of 15 mgKOH / g, and a glass transition temperature of 15 ° C. Resin 5 was obtained. In addition, in 100 mol% of all the monomers used for the reaction, the amount of the monomer having a C20-60 hydrocarbon group was 59.7 mol%.

Synthesis example 6
72.6 parts (0.40 mol) of 5-hydroxyisophthalic acid as a polybasic acid compound having a phenolic hydroxyl group was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer. 138.2 parts (0.60 mol) of dodecanedioic acid as another polybasic acid compound, 164.5 parts (0.97 mol) of isophoronediamine as another polyamine compound, 100 parts of ion-exchanged water were charged, and the temperature of heat generation was constant. It was stirred until. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant is added, and a weight average molecular weight of 20,000, an acid value of 11.2 mgKOH / g, an amine value of 0.4 mgKOH / g, a phenolic hydroxyl value of 60.0 mgKOH / g, and a glass transition temperature of 100 ° C phenolic hydroxyl group. A polyamide resin 6-a-1 containing was obtained.
Further, 578.5 parts of PRIPOL 1009 as a polybasic acid compound having 36 carbon atoms (1 in terms of dibasic acid: 1. 00 mol), 516.2 parts of preamine 1074 (0.97 mol in terms of diamine) as a polyamine compound having 36 carbon atoms, and 100 parts of ion-exchanged water were charged, and the mixture was stirred until the temperature of heat generation became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant is added, and a polyamide resin having a C20-60 hydrocarbon group having a mass average molecular weight of 20600, an acid value of 10.9 mgKOH / g, an amine value of 0.4 mgKOH / g, and a glass transition temperature of -40 ° C 6- I got a-2.
Finally, 100 parts of the phenolic hydroxyl group-containing polyamide resin 6-a-1 synthesized above was added to a 4-neck flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, an inlet tube, and a thermometer, and C20-60 carbonized. 400 parts of polyamide resin 6-a-2 having a hydrogen group was charged and melt-kneaded at 180 ° C. for 30 minutes to obtain a mass average molecular weight of 20,500, an acid value of 11 mgKOH / g, an amine value of 0.4 mgKOH / g, and a phenolic hydroxyl value of 12 mgKOH. / G, glass transition temperature of -3 ° C to obtain a phenolic hydroxyl group-containing polyamide resin 6. In addition, in 100 mol% of all the monomers used for the reaction, the amount of the monomer having a C20-60 hydrocarbon group was 56.2 mol%.

Synthesis Example 7
In a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer, 87.4 parts (0.48 mol) of 5-hydroxyisophthalic acid as a polybasic acid having a phenolic hydroxyl group and a carbon number 300.8 parts of Pripol 1009 (0.52 mol in terms of dibasic acid) as a polybasic acid compound of 36, 428.5 parts of Priamine 1074 (0.8 mol in terms of diamine) as a polyamine compound of 36 carbon atoms, carbon number As the polyol 36, 75.3 parts (0.14 mol in terms of diol) of Pripol 2033 was charged, and the temperature was raised to 60 ° C. with stirring under a nitrogen stream to uniformly dissolve. Subsequently, 0.77 part of tetrabutyl orthotitanate as a catalyst was added thereto and reacted at 110 ° C. for 3 hours. After that, the temperature is raised to 230 ° C., held under a vacuum of about 2 kPa for 1 hour, further reacted under a vacuum of about 1 kPa for 2 to 3 hours, and finally, an antioxidant is added, and a mass average molecular weight of 30300, A phenolic hydroxyl group-containing polyesteramide resin 7 having an acid value of 7.3 mgKOH / g, a phenolic hydroxyl group value of 30.3 mgKOH / g and a glass transition temperature of -20 ° C was obtained. The ester bond is 7.3 mol% in the total 100 mol% of the amide bond and the ester bond in the polyesteramide resin 7.

Comparative Synthesis Example 1
In a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer, 15.8 parts of ethylene glycol, 5.3 parts of 1.6-hexanediol, and 49.8 parts of toluene diisocyanate were placed. After charging, the temperature was raised to 60 ° C. with stirring under a nitrogen stream to uniformly dissolve it. Subsequently, 0.006 parts of dibutyltin dilaurate as a catalyst was added thereto and reacted at 110 ° C. for 3 hours. Thereafter, the temperature was lowered, 5.5 parts of trimellitic anhydride was added, and the mixture was reacted at 110 ° C. for 3 hours to obtain a polyurethane resin 1 having a mass average molecular weight of 14900, an acid value of 42 mgKOH / g, and a glass transition temperature of 5 ° C. .

Comparative synthesis example 2
In a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet pipe, an inlet pipe, and a thermometer, 289.2 parts of PRIPOL 1009 as a polybasic acid compound having 36 carbon atoms and dodecane dichloride as another polybasic acid compound were used. 115.2 parts of acid, 523.9 parts of preamine 1074 as a polyamine compound having 36 carbon atoms, and 100 g of ion-exchanged water were charged, and the mixture was stirred until the temperature of heat generation became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant was added to obtain a polyamide resin 2 having a mass average molecular weight of 91100, an acid value of 2.4 mgKOH / g, an amine value of 0.3 mgKOH / g, and a glass transition temperature of -10 ° C.

Comparative Synthesis Example 3
As a polybasic acid having a phenolic hydroxyl group, 10.9 parts of 5-hydroxyisophthalic acid was added to a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet pipe, an inlet pipe, and a thermometer. 216.5 parts of dodecanedioic acid, 166.9 parts of isophoronediamine as another polyamine compound, and 100 g of ion-exchanged water were charged, and the mixture was stirred until the temperature of heat generation became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant is added, and a polyamide resin 3 having a mass average molecular weight of 36600, an acid value of 6.1 mgKOH / g, an amine value of 0.4 mgKOH / g, a phenolic hydroxyl value of 8.5 mgKOH / g, and a glass transition temperature of 55 ° C. Got

Comparative Synthesis Example 4
As a polybasic acid having a phenolic hydroxyl group, 18.2 parts of 5-hydroxyisophthalic acid was added to a 4-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet pipe, an inlet pipe, and a thermometer. 149.5 parts of isophthalic acid, 198.9 parts of 4,4-diaminodiphenyl ether as another polyamine compound, and 100 g of ion-exchanged water were charged, and the mixture was stirred until the temperature of heat generation became constant. After the temperature became stable, the temperature was raised to 110 ° C., after confirming the outflow of water, the temperature was raised to 120 ° C. 30 minutes later, and then the dehydration reaction was continued while raising the temperature by 10 ° C. every 30 minutes. . When the temperature reached 230 ° C., the reaction was continued at the same temperature for 3 hours and kept under a vacuum of about 2 kPa for 1 hour to lower the temperature. Finally, an antioxidant was added, and the mass average molecular weight was 98,000, the acid value was 2.3 mgKOH / g, the amine value was 0.3 mgKOH / g, the phenolic hydroxyl value was 15.4 mgKOH / g, and the glass transition temperature was 200 ° C. Polyamide resin 4 was obtained.

Comparative Synthesis Example 5
In a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, an introduction tube, and a thermometer, 295.0 g of PRIPOL 1009 as a polybasic acid compound having 36 carbon atoms and 5 as a polybasic acid having a phenolic hydroxyl group -Hydroxyisophthalic acid 89.2 parts, 522.3 parts of Pripol 2033 as a polyol having 36 carbon atoms, and 139.3 parts of toluene were charged, and heated to 60 ° C with stirring under a nitrogen stream and uniformly dissolved. . Subsequently, 0.77 part of tetrabutyl orthotitanate as a catalyst was added thereto and reacted at 110 ° C. for 3 hours. After that, the temperature is raised to 230 ° C., held for 1 hour under a vacuum of about 2 kPa, further reacted under a vacuum of about 1 kPa for 2 to 3 hours, and finally, an antioxidant is added, and a mass average molecular weight of 100700, A phenolic hydroxyl group-containing polyester resin 5 having an acid value of 2.2 mgKOH / g, a phenolic hydroxyl value of 30.3 mgKOH / g and a glass transition temperature of -15 ° C was obtained.

(Compound B)
Compound B1: TETRAD-X (4 functional) manufactured by Mitsubishi Gas Chemical Co., Inc., 2000 mPa · s (25 ° C.)
Compound B2: jER604 (4 functional) manufactured by Mitsubishi Chemical Corporation, 7500 mPa · s (25 ° C.)
Compound B3: Epototo YD-171 (tetrafunctional) manufactured by Nippon Steel Chemical Co., Ltd., 650 mPa · s (25 ° C.)

(Thermally conductive filler C)
Boron Nitride 1: Agglomerates 100 (manufactured by 3M)
Boron Nitride 2: PTX60 (made by Momentive)
Spherical alumina 1: Admafine AO-509 (manufactured by Admatex)

(solvent)
Solvent 1: Toluene / isopropanol = 50/50 (mass ratio)
Solvent 2: N-methylpyrrolidone

Example 1 (Preparation of precursor sheet)
Boron nitride was added to 50.0 parts of Resin 1 obtained in Synthesis Example 1, 5.0 parts of Compound B1, and 55.0 parts of a mixed solvent of toluene / isopropanol = 50/50 (mass ratio). 45.0 parts of 1 was added, the mixture was stirred with a disperser, and then defoamed in an ultrasonic stirrer for 2 minutes to obtain a coating liquid, and a release sheet (thickness of 75 μm was used for release treatment) using a 6 MIL blade coater. Polyethylene terephthalate film), and dried at 100 ° C. for 2 minutes to obtain a precursor sheet with a release sheet in which one surface of the precursor sheet having a film thickness of 120 μm was covered with the release sheet.

Examples 2-15, Comparative Examples 1-7
Precursor sheets were prepared in the same manner as in Example 1 according to the compositions shown in Tables 2 to 4.
The precursor sheets obtained in Examples and Comparative Examples were evaluated for thermal conductivity, initial adhesive strength, moist heat resistance, heat resistance, and heat cycle resistance by the following methods.

<Evaluation>
<Thermal conductivity>
The surface of the precursor sheet with the release sheet, which is not covered with the release sheet, is covered with the same release sheet as described above, and heat-pressed at 180 ° C. for 1 hour at a pressure of 1 MPa, and then the release sheet is peeled off. Thus, the heat conductive sheet was isolated. The obtained heat conductive sheet was cut into 15 mm square, the sample surface was vapor-deposited with gold and carbon-coated with carbon spray, and then the thermal diffusivity at 25 ° C. was measured with a xenon flash analyzer LFA447 NanoFlash (manufactured by NETZSCH). It was measured.
The specific heat capacity was measured using a high sensitivity differential scanning calorimeter DSC220C manufactured by SII Nano Technology Co., Ltd. Furthermore, the density was calculated using the underwater substitution method. Regarding the thermal conductivity, the thermal conductivity was calculated based on the following formula, and the result was judged according to the following criteria.
Conductivity (W / m · K) = density (g / cm ³ ) × specific heat (J / kg · K) × thermal diffusivity (mm ² / s).
⊚: “10 (W / m · K) <thermal conductivity”
◯: "5 (W / mK) <thermal conductivity ≤ 10 (W / mK)"
Δ: “3 (W / m · K) <thermal conductivity ≦ 5 (W / m · K)”
X: "Thermal conductivity ≤ 3 (W / mK)"

[Adhesive strength]
<Initial>
The release sheet is peeled from the release sheet-attached precursor sheet, the isolated precursor sheet is sandwiched between an aluminum plate and a copper foil, hot pressed at 180 ° C. for 1 hour at a pressure of 1 MPa, and then at 23 ° C. relative humidity. In a 50% atmosphere, a 180 ° peel test was performed at a pulling speed of 300 mm / min to measure the initial adhesive force (N / cm). This test evaluates the initial adhesive strength of the adhesive layer when used at room temperature, and the results were judged according to the following criteria.
◎: “15 (N / cm) <initial adhesive strength”
○: "10 (N / cm) <initial adhesive strength ≤ 15 (N / cm)"
△: "5 (N / cm) <initial adhesive strength ≤ 10 (N / cm)"
X: “Initial adhesive strength ≦ 5 (N / cm)”

<Heat resistance test>
Similarly to the measurement of the initial adhesive force, the adhesive force (N / cm) was measured after hot pressing was performed at 180 ° C. for 1 hour at a pressure of 1 MPa, and after being stored in an air atmosphere at 175 ° C. for 1000 hours. From there, the adhesive strength retention rate was calculated based on the following formula, and the result was judged according to the following criteria.
Adhesive strength retention rate (%) = [100− (initial adhesive strength−adhesive strength after test) / initial adhesive strength] × 100.
◯: “90 (%) <Adhesive strength retention rate”
Δ: “70 (%) <Adhesive force retention rate ≦ 90 (%)”
X: "Adhesive force retention rate ≤ 70 (%)"

<After moisture and heat resistance test>
Similarly to the measurement of the initial adhesive strength, heat pressing was performed at 180 ° C. for 1 hour at a pressure of 1 MPa, and the adhesive strength (N / cm) was measured after storing for 1000 hours in an atmosphere of 85 ° C. and 85% relative humidity. From there, the adhesive strength retention rate after the test was obtained in the same manner as described above, and the same criteria were used for judgment.
◯: “90 (%) <Adhesive strength retention rate”
Δ: “70 (%) <Adhesive force retention rate ≦ 90 (%)”
X: "Adhesive force retention rate ≤ 70 (%)"

<Heat cycle test>
Similar to the initial adhesive strength measurement, after heat-pressing at 180 ° C. for 1 hour at a pressure of 1 MPa, high temperature side 150 ° C. to low temperature side −40 ° C., holding for 30 minutes each, heat cycle of 1000 cycles was applied, and aluminum was applied. The presence or absence of peeling or cracks of the heat conductive sheet from the plate or the copper foil was observed. The presence or absence of peeling and cracks of the heat conductive sheet was observed using an ultrasonic deep scratch device (S AT). The results were judged according to the following criteria.
◯: No crack or peeling.
X: There is crack or peeling.

As can be seen from Tables 2 to 4, none of the heat conductive sheets shown in the comparative examples satisfied all of high heat conductivity, adhesive strength, moist heat resistance, heat resistance and heat cycle resistance.
On the other hand, in the heat conductive sheet shown in the examples, good results with good balance in all physical properties were obtained, and in particular, there was a trade-off relationship in the comparative example, moist heat resistance, both heat resistance and heat cycle resistance, high. We were able to achieve both thermal conductivity and heat cycle resistance. This is because the use of the polyamide (A) having a phenolic hydroxyl group in the side chain and the compound (B), which is a feature of the present invention, improves wet heat resistance and heat resistance, and the polyamide (A) has 20 carbon atoms. It is considered that this is because the presence of the hydrocarbon group of -60 shows high flexibility and the heat cycle resistance is improved.

Claims (10)

A polymer of a polybasic acid monomer and a polyamine monomer, having a phenolic hydroxyl group in the side chain (A), and a trifunctional or higher functional compound (B) capable of reacting with the phenolic hydroxyl group, A heat conductive sheet containing a heat conductive filler (C),
The polyamide (A) is the following (i) and / or (ii),
Furthermore, satisfying (iii) to (vi),
The compound (B) satisfies the following (vii) ,
The heat conductive filler (C) is boron nitride,
A heat conductive sheet containing 60 to 75 mass% of the heat conductive filler (C) in a total of 100 mass% of the polyamide (A), the compound (B) and the heat conductive filler (C) .
(I) The polyamide (A) is a polyamide (A- in which the phenolic hydroxyl group and the hydrocarbon group having 20 to 60 carbon atoms (however, the aromatic ring to which the phenolic hydroxyl group is bonded are not included) are contained in the same polymer. 1).
(Ii) The polyamide (A) is a polyamide (A-) obtained by mixing a polyamide (a-1) containing a phenolic hydroxyl group in a side chain and a polyamide (a-2) containing a hydrocarbon group having 20 to 60 carbon atoms. 3).
(Iii) As the monomer constituting the polyamide (A-1), a monomer having a phenolic hydroxyl group and a monomer having a hydrocarbon group having 20 to 60 carbon atoms are included.
(Iv) The polybasic acid monomer or / and the polyamine monomer constituting the polyamide (a-1) contains a monomer having a phenolic hydroxyl group, and the polybasic acid monomer and The polyamine monomer does not include a monomer having a hydrocarbon group having 20 to 60 carbon atoms.
(V) The polybasic acid monomer and / or the polyamine monomer forming the polyamide (a-2) contains a monomer having a hydrocarbon group having 20 to 60 carbon atoms, and The basic acid monomer and the polyamine monomer do not include a monomer having a phenolic hydroxyl group.
(Vi) At least a part of the monomer having a hydrocarbon group having 20 to 60 carbon atoms includes a compound having a cyclic structure having 5 to 10 carbon atoms.
(Vii) The compound (B) is at least one selected from the group consisting of an epoxy group-containing compound, an isocyanate group-containing compound, a carbodiimide group-containing compound, a metal chelate, a metal alkoxide and a metal acylate. The heat conductive sheet according to claim 1, wherein the compound (B) is an epoxy compound having a viscosity of 10 to 1,000,000 mPa · S at 25 ° C. The heat conductive sheet according to claim 1 or 2 , wherein the polyamide (A) has a phenolic hydroxyl value of 1 to 60 mgKOH / g. During all the monomers 100 mol% constituting the polyamide (A), heat as claimed in any one of claims 1 to 3 containing 40 to 95 mol% of a monomer having a hydrocarbon group having 20 to 60 carbon atoms Conductive sheet. Monomers having a hydrocarbon group having 20 to 60 carbon atoms, a monomer containing a dimer derived from monobasic unsaturated fatty acids having 10 to 24 carbon atoms as a residue, claim 1-4 The heat conductive sheet according to any one of items. The glass transition temperature of the polyamide (A) is -40~60 ℃, thermally conductive sheet according to any one of claims 1-5. Thermally conductive sheet according to any one of claims 1 to 6 weight-average molecular weight of the polyamide (A-1) is 10,000 to 500,000. Thermally conductive sheet according to any one of claims 1 to 7 weight-average molecular weight of the polyamide (a-2) is 10,000 to 500,000. Thermally conductive sheet according to any one of claims 1-8 weight-average molecular weight of the polyamide (a-1) is 500 to 30,000. The heat conductive sheet according to any one of claims 1 to 9 , wherein the polyamide (A) further satisfies (viii) to (ix).
(Viii) A part of the monomer having a hydrocarbon group having 20 to 60 carbon atoms contained as a monomer constituting the polyamide (A-1) is a trifunctional or higher polybasic acid compound and a trifunctional or higher functional compound. At least one of the polyamine compounds described above.
(Ix) A part of the monomer having a hydrocarbon group having 20 to 60 carbon atoms contained as a monomer constituting the polyamide (a-2) is a trifunctional or more polybasic acid compound and a trifunctional or more polyfunctional acid compound. At least one of the polyamine compounds described above.