JP2007224060A - Heat radiation material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat radiation material having excellent heat and moisture resistances, heat conductivity, mechanical strength, low stress properties, electrical insulating properties and molding processability. <P>SOLUTION: The heat radiation material comprises at least a cured product of a bismaleimide represented by general formula (I) (wherein, I represents a maleimide group; Ms represent each a mesogen group; and S represents a spacer). The heat radiation material comprises at least the cured product of a bismaleimide represented by general formula (II). The bismaleimide compound is represented by general formula (II). A resin composition comprises the compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat dissipation material excellent in heat resistance, thermal conductivity, moisture resistance, mechanical strength, low stress, electrical insulation, and molding processability, a novel bismaleimide compound, and a resin composition containing the compound.

  In recent years, with the increase in functionality, size, and weight of electronic devices, the density of electronic components has been increasing. As a result, the amount of heat generated in the electronic component is remarkably increased, which contributes to a decrease in reliability and life of the component. As described above, the heat problem in the electronic device is a very important issue, and the heat dissipation material used for the countermeasure is required to further improve the thermal conductivity. As a measure for improving the thermal conductivity of a resin material used in a field where electrical insulation is particularly required among heat dissipation materials, a method of adding a filler such as inorganic ceramics having high thermal conductivity is generally used. In these methods, it is difficult to obtain sufficient thermal conductivity due to the limitation of the addition amount, and improvement of the thermal conductivity of the resin itself is required.

  As thermosetting resins having high thermal conductivity, for example, epoxy resins as described in Patent Document 1 and Patent Document 2 have been reported. Although the resin is effective to some extent in terms of thermal conductivity, it has not always been able to sufficiently meet the demands in the fields that require high heat resistance and moisture resistance, as well as mechanical strength and low stress.

  On the other hand, bismaleimide resin is a thermosetting resin and has been put to practical use in the fields of molding materials and laminated materials as a material having excellent heat resistance and moisture resistance. However, conventionally reported thermosets of bismaleimide resins are extremely fragile and easily cracked, as in general epoxy resins, and have a large practical problem in terms of mechanical strength. Moreover, the thing which expresses liquid crystallinity among bismaleimide compounds has already been reported (for example, nonpatent literature 1). However, the thermal conductivity, mechanical strength, and low stress properties of these liquid crystalline bismaleimides are not discussed at all, and the possibility of practical use as a heat dissipation material is not shown at all.

As described above, there has been a strong demand for the development of a heat dissipation material that is excellent in heat resistance, thermal conductivity, moisture resistance, mechanical strength, low stress properties, electrical insulation, and moldability.
JP-A-11-323162 Republication No. 02/094905 Macromol. Chem. Phys. , No. 17, 201 (2000)

    The present invention has been made in view of the above circumstances, and is to provide a heat dissipating material that is excellent in heat resistance, thermal conductivity, moisture resistance, mechanical strength, low stress, electrical insulation, and moldability. .

  As a result of intensive studies to solve the above problems, the present inventors have found that a cured product of a specific bismaleimide has heat resistance, thermal conductivity, moisture resistance, mechanical strength, low stress, electrical insulation, and Since it was excellent in molding processability, it was found to be extremely useful for application to a heat dissipation material, and the present invention was completed.

That is, the present invention includes the following (1) to (6).
(1) A heat dissipation material containing at least a cured product of bismaleimide represented by the general formula (I).

(In the formula, I represents a maleimide group, M represents a mesogenic group, and S represents a spacer.)
(2) A heat dissipation material containing at least a cured product of bismaleimide represented by the general formula (II).

(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y and z represents a divalent substituent composed are each independently a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO _{-, - CO-O -,} - CO-NH -, - C (CH 3) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O A divalent substituent selected from the group of N).
(3) The heat dissipating material according to (1) or (2), further containing an inorganic filler.
(4) The inorganic filler is selected from aluminum oxide, aluminum nitride, aluminum fluoride, calcium fluoride, silica, silicon nitride, silicon carbide, boron nitride, magnesium oxide, beryllium oxide, tin oxide, graphite, carbon fiber, and diamond. The heat dissipating material according to (3), which is at least one kind.
(5) A resin composition containing at least a bismaleimide represented by the general formula (II).

(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is a group of 2 to 20 atoms represented by a combination of —CH ₂ —, —Si (CH ₃ ) ₂ —, and —O— .y and z represents a divalent substituent composed are each independently a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO _{-, - CO-O -,} - CO-NH -, - C (CH 3) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O A divalent substituent selected from the group of N).
(6) A bismaleimide represented by the general formula (III).

(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y showing a divalent substituent composed of a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-NH _{-, - C (CH 3)} = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 valent selected from the group consisting of N- .z illustrating a substituent, a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-O -, - C _{-NH -, - C (CH 3} ) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 selected from the group consisting of N- A valent substituent.)

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the heat radiating material which is excellent in heat resistance, heat conductivity, moisture resistance, mechanical strength, low stress property, electrical insulation, and moldability.

  The heat dissipation material of the present invention is characterized by containing at least a cured product of bismaleimide represented by the general formula (I).

(In the formula, I represents a maleimide group, M represents a mesogenic group, and S represents a spacer.)
The heat dissipation material of the present invention is a heat dissipation material containing at least a cured product of bismaleimide represented by the following general formula (II).

(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y and z represents a divalent substituent composed are each independently a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO _{-, - CO-O -,} - CO-NH -, - C (CH 3) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O A divalent substituent selected from the group of N).

The mesogenic group contained in the bismaleimide according to the present invention means a rigid and highly oriented substituent. Specifically, it is a portion corresponding to -A ₁ -z-A ₂ -contained in the general formula (II), and A ₁ and A ₂ are each independently an aromatic group, a condensed aromatic group, an oil A divalent substituent selected from cyclic heterocyclic groups or a direct bond is shown. However, A ₁ and A ₂ are not directly bonded at the same time. Specific examples of the aromatic group, condensed aromatic group, and alicyclic heterocyclic group include phenylene, biphenylene, naphthylene, anthracenylene, bicyclooctane, bicyclononane, and bicyclodecane. z is each independently a direct bond, —O—, —CH ₂ —CH ₂ —, —CH═CH—, —C≡C—, —CO—, —CO—O—, —CO—NH—, A divalent substituent selected from the group of —C (CH ₃ ) ═CH—, —CH═N—, —CH═N—N═CH—, —N═N— or —N (O) ═N—. Indicates.

  Specific examples of mesogenic groups include biphenyl, diphenyl ether, stilbene, diphenylacetylene, benzophenone, phenylbenzoate, phenylbenzamide, 1,2-diphenylpropene, N-benzylidenebenzeneamine, 1,2-dibenzylidenehydrazine, azobenzene, 2-naphthoate , Phenyl-2-naphthoate, bicyclo [2.2.2] octane-1-carboxylate, phenylbicyclo [2.2.2] octane-1-carboxylate, and the like. Biphenyl, stilbene, diphenylacetylene, phenylbenzoate, azobenzene, 2-naphthoate, bicyclo [2.2.2] octane-1-carboxylate, and the like are preferable.

The spacer contained in the bismaleimide according to the present invention means a flexible molecular chain. Specifically included in the formula (II), a portion corresponding to -y-x-y-, x _{is, -CH 2 -, - Si (} CH 3) 2 -, or -O- group of 2 to be represented by combining chosen from a divalent substituent composed of 20 atomic group, y _{is, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C ≡C -, - CO -, - CO-O -, - CO-NH -, - C (CH 3) = CH -, - CH = N -, - CH = N-N = CH -, - N = N A divalent substituent selected from the group of-or -N (O) = N- is shown. Any number of atomic groups constituting x may be selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. When the number of atomic groups constituting x is small, sufficient flexibility is not exhibited in the molecular structure of bismaleimide, and there is a possibility that favorable characteristics for mechanical strength and thermal conductivity after curing cannot be obtained. Moreover, when there are too many atomic groups, the heat resistance of resin may fall. Specific examples of x include alkylene groups having 2 to 20 carbon atoms, polysiloxane groups having 2 to 10 silicon atoms, polyoxyethylene groups having 2 to 10 carbon atoms, or — (CH ₂ ) _n —Si (CH ₃ ) _2. And a modified polysiloxane group represented by — [O—Si (CH ₃ ) ₂ ] _m — (CH ₂ ) _n —. Here, m represents an integer of 1 to 4, and n represents an integer of 1 to 5.

Specific examples of the spacer corresponding to the -y-x-y-, other substituents shown in the specific examples of the _{x, -O- (CH 2) h} -O -, - CO-NH- (CH 2 ) _I —NH—CO—, —CO—O— (CH ₂ ) _i —O—CO—, —O— (CH ₂ —CH ₂ —O) _k —, —CO—NH— (CH ₂ ) _n — _{Si (CH 3) 2 - [} O-Si (CH 3) 2] m - (CH 2) can be exemplified n -NH-CO- substituent represented by any one of. Where h is an integer from 1 to 20, i is an integer from 1 to 5, k is an integer from 1 to 10, m is an integer from 1 to 4, and n is an integer from 1 to 5. _{Further, -O- (CH 2) 6 -O} -, - O- (CH 2) 8 -O -, - O- (CH 2) 10 -O -, - CO-NH- (CH 2) 3 -Si (CH ₃ ) ₂ —O—Si (CH ₃ ) ₂ — (CH ₂ ) ₃ —NH—CO— and —O— (CH ₂ —O) ₃ — are particularly preferred examples.

  The bismaleimide compound according to the present invention may be produced by any known method. For example, as described in the aforementioned known non-patent document (Macromol. Chem. Phys., No. 17, 201 (2000)), a diol compound synthesized in advance is mixed with a known compound 4-maleimidobenzoyl chloride at room temperature. And synthesized in advance as described in known patent documents (Japanese Patent Publication No. 46-23250, Japanese Patent Publication No. 49-40231, Japanese Patent Publication No. 59-52660, Japanese Patent Publication No. Sho 62-155255). Examples thereof include a method in which a diamine compound and maleic anhydride are subjected to a ring-opening addition reaction at room temperature to form bismaleamic acid, followed by dehydration cyclization at 50 to 60 ° C. in the presence of a catalyst using acetic anhydride as a dehydrating agent.

The bismaleimide cured product according to the present invention is preferably heated at a temperature of 100 to 300 ° C., more preferably 120 to 250 ° C., depending on the bismaleimide used. However, if the heating temperature is too high, the higher order structure formed by the molecular arrangement of bismaleimide may not be dense, and the thermal conductivity may not be sufficiently improved. On the other hand, if the heating temperature is too low, the mechanical strength of the heat-dissipating material obtained without sufficient curing may not be obtained. Moreover, the pressure at the time of hardening becomes like this. Preferably it is about 1-100 kg / cm < ² >, and heat-pressing time becomes like this. Preferably it is about 1-600 minutes, and can be suitably determined with the bismaleimide to be used. If the heating and pressurizing time is too short, curing does not occur sufficiently, and there is a possibility that sufficient mechanical strength of the obtained heat dissipation material cannot be obtained. If the heating and pressurizing time is too long, productivity may be reduced.

  In addition to the bismaleimides represented by the above general formulas (I) to (II), the cured product of bismaleimide according to the present invention is a diamine, dicyanate, or olefin-based one as long as the effects of the present invention are not lost. A cured product obtained by copolymerization with a saturated monomer or a known compound that has conventionally been known to be reactive with bismaleimide may also be included.

Examples of preferred diamines used in producing the bismaleimide compound in the present invention include:
4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylmethane, 2,2-bis (4-aminophenyl) propane,
1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) Benzene, 1,3-bis (3-aminobenzoyl) benzene, 1,3-bis (4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4-amino) Benzoyl) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl Ether, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane,

1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8- Diaminooctane, 1,10-diaminodecane,
1,4-diaminocyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohexyl) methane, 2,6-bis ( Aminomethyl) bicyclo [2,2,1] heptane, 2,5-bis (aminomethyl) bicyclo [2,2,1] heptane, piperazine and the like.

  Examples of preferred dicyanates used in producing the bismaleimide compound in the present invention include 1,3-dicyanate benzene, 1,4-dicyanate benzene, 1,3-dicyanate naphthalene, 1,4-dicyanate naphthalene, 1,6-dicyanate naphthalene, 1,8-dicyanate naphthalene, 2,6-dicyanate naphthalene, 2,7-dicyanate naphthalene, 4,4-di Examples include cyanate biphenyl, bis (4-dicyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, and bis (4-cyanatophenyl) ether.

  Examples of preferred olefinic unsaturated monomers used in producing the bismaleimide compound in the present invention include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene. 1-decene, 1-dodecene, 2,2-diallylbisphenol A, 2,2-dipropenyl bisphenol A, m-divinylbenzene, p-divinylbenzene, m-diisopropenylbenzene, p-diisopropenylbenzene, etc. Is mentioned. The amount of the monomer to be copolymerized is generally preferably in the range of 0 to 100 mol per 100 mol of bismaleimide. If the amount used is too large, the thermal conductivity may not be sufficiently improved.

  In the heat dissipation material of the present invention, the curing catalyst is not necessarily an essential component, but one or more kinds can be used as necessary. In this case, the amount used is not limited as long as the effects of the present invention are not lost. Preferred curing catalysts used as needed include, for example, peroxides such as dicumyl peroxide, t-butyl perbenzoate, methyl ethyl ketone peroxide, azo compounds such as azobisisobutyronitrile, N-methylimidazole , Imidazole compounds such as N-phenylimidazole, metal compounds such as zinc acetate, sodium acetate, titanium acetylacetonate and sodium methylate, acids such as maleic anhydride, methyltetrahydrophthalic anhydride, nadic anhydride and pyromellitic anhydride Anhydrides, triethylamine, N, N-dimethylbenzylamine, hexamethylenetetramine, tertiary amines such as N, N-dimethylaniline, quaternary ammonium salts such as tetramethylammonium bromide, triphenylborate, tricresylboret Borate compounds such as preparative, boron trifluoride monoethyl complexes, and boron trifluoride-amine complex such as boron trifluoride piperidine complex. The preferable usage-amount of a curing catalyst is the range of 0.1-10 mass parts with respect to 100 mass parts of bismaleimide normally contained in a thermal radiation material.

  In addition to the bismaleimides represented by the above general formulas (I) to (II), the heat dissipation material of the present invention includes an epoxy resin and a polyolefin, depending on the purpose within a range not losing the effect of the present invention. Any known resin such as resin, bismaleimide resin, polyimide resin, polyether resin, phenol resin, silicone resin, polycarbonate resin, polyamide resin, polyester resin, fluororesin, acrylic resin, melamine resin, urea resin, urethane resin may be included. It doesn't matter. Specific examples of preferred resins include polybutadienes such as 1,2-polybutadiene and 1,4-polybutadiene. The preferred amount of resin used is in the range of 0 to 50 parts by mass with respect to 100 parts by mass of bismaleimide usually contained in the heat dissipation material.

  The heat-dissipating material of the present invention further includes any other component depending on the purpose, for example, a reinforcing agent, a thickening agent, a release agent, a coupling agent, a flame retardant, a flame retardant, a pigment, a colorant, and other auxiliary agents. Etc. can be added as long as the effects of the present invention are not lost.

  In addition to the cured bismaleimide represented by the general formula (I) or (II), the heat dissipating material of the present invention also preferably contains an inorganic filler.

  The inorganic filler according to the present invention is not particularly limited. For example, preferable examples of improving the thermal conductivity of the resin composition include aluminum oxide, aluminum nitride, aluminum fluoride, calcium fluoride, silica, silicon nitride, silicon carbide, Examples thereof include boron nitride, magnesium oxide, beryllium oxide, tin oxide, graphite, carbon fiber, and diamond. These inorganic fillers may be used alone or in combination of two or more. Among these, since aluminum oxide, aluminum nitride, aluminum fluoride, calcium fluoride, silica, silicon nitride, silicon carbide, boron nitride, and magnesium oxide maintain insulation, the heat dissipation material of the present invention is required to have insulation. This is preferable because it can be widely applied to various fields. The addition amount is not particularly limited, but if it is too large, the moldability of the resin composition is lowered, and the mechanical strength of the resulting cured product is lowered, which is not preferable. As a preferable addition amount, the range of 0 to 80 parts by mass, more preferably 0 to 70 parts by mass of the inorganic filler can be given with respect to 100 parts by mass of the resin.

  The method for adding the inorganic filler is not particularly limited. Specifically, as a method of addition, a method of directly adding and stirring to bismaleimide, a method of adding and kneading bismaleimide in a molten state, and adding and stirring in a state where bismaleimide is dissolved or dispersed in a solvent Methods and the like.

    The manufacturing method of the heat radiating material of the present invention is not limited, and can be manufactured in a desired shape by a known resin molding method, that is, a transfer molding, injection molding, casting method or the like.

  The heat-dissipating material of the present invention can also be produced in the form of a laminate by applying or impregnating a desired base material, laminating and curing. In this case, although the base material used is not specifically limited, As a preferable example, a glass cloth, a glass nonwoven fabric, carbon fiber, a synthetic fiber cloth, a synthetic fiber nonwoven fabric, paper etc. can be mentioned. The bismaleimide cured product according to the present invention is excellent in adhesiveness with a base material and can be practiced without using an ordinary adhesive, but within the range that does not impair the effects of the present invention depending on the purpose. An adhesive such as a coupling agent or various surface treatment agents may be applied to the substrate surface in advance. In producing the heat dissipation material of the present invention, the method of applying or impregnating on a desired substrate is not particularly limited, for example, application using a spin coater, application using a spray coater, application using a bar coater, Spraying, dipping, printing, etc. can be mentioned. The amount to be applied is not particularly limited, but for example, it is applied such that the final film thickness after curing is 0.1 μm to 100 μm, more generally 1 to 50 μm. After coating and impregnation, a prepreg is produced through a drying process. About drying conditions, it determines suitably by the boiling point of the solvent to be used. The prepreg thus obtained is produced by laminating one or a plurality of laminated prepregs by heating and pressing. In manufacturing a laminated plate-shaped heat dissipation material, a conductive layer or an insulating layer can be overlaid on one or both surfaces of the outermost layer. Examples of preferred conductive layers include copper foil, copper plate, aluminum foil, aluminum plate, iron foil, iron plate, stainless steel foil, stainless steel plate, gold foil, gold plate, silver foil, silver plate and the like. Examples of the insulating layer include a ceramic substrate and a resin sheet. Moreover, it is good also as a laminated board for multilayer printed wiring boards using an inner layer core material.

  The heat dissipating material of the present invention is excellent in heat resistance, thermal conductivity, moisture resistance, mechanical strength, low stress, electrical insulation, and molding processability, so that circuit board materials, resistors, inductors, capacitors, etc. Sealing material or electronic component case, IC / power transistor element sealing material, light bulb used in lighting equipment, LED, semiconductor laser and other light emitting element sealing materials and base substrate materials, notebook computers and mobile phones Automobile parts such as telephone casings, lamp reflectors, motor case parts for motor cores, motor parts such as casings, sliding parts such as bearing members, cooling parts such as radiating fins, heat sinks and heat pipes, heat exchangers It is extremely useful for OA / communication equipment parts such as parts and copier roller members.

  The present invention also provides a resin composition containing at least a bismaleimide represented by the general formula (II).

(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y and z represents a divalent substituent composed are each independently a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO _{-, - CO-O -,} - CO-NH -, - C (CH 3) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O A divalent substituent selected from the group of N).

  As long as the bismaleimide compound is contained in the resin composition of the present invention, any other component may be further contained depending on the purpose as long as the effects of the present invention are not lost. The resin composition of the present invention may be in the form of a solvent-free or in the form of a solution / suspension containing a solvent.

  In the resin composition of the present invention, known fillers can be widely used depending on the purpose. Examples of the filler include metal oxides such as magnesium oxide; metal hydroxides such as aluminum hydroxide; metal carbonates such as calcium carbonate and magnesium carbonate; diatomaceous earth powder; Magnesium acid; calcined clay; fine powder silica, quartz powder, crystalline silica; kaolin, talc; carbon black; antimony trioxide; fine powder mica; graphite; molybdenum disulfide; carbon fiber; rock wool; Fiber; Paper, pulp, wood; Synthetic fiber such as polyamide fiber, aramid fiber, and boron fiber; Resin powder such as polyolefin powder, and glass filler such as glass fiber, glass powder, glass cloth, and fused silica . By using these fillers, it is possible to improve favorable characteristics in applying a resin composition such as thermal conductivity, mechanical strength, and abrasion resistance.

  The resin composition of the present invention includes a sealing material, a substrate material, an adhesive material, a display material, which are required to have heat resistance, thermal conductivity, moisture resistance, mechanical strength, low stress, electrical insulation, and moldability. It is useful as a raw material for recording materials, sliding component materials, and heat dissipation materials.

  The present invention also provides a bismaleimide compound represented by the following general formula (III).

(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y showing a divalent substituent composed of a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-NH _{-, - C (CH 3)} = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 valent selected from the group consisting of N- .z illustrating a substituent, a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-O -, - C _{-NH -, - C (CH 3} ) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 selected from the group consisting of N- A valent substituent.)

  Since the bismaleimide of the present invention has a spacer in the molecule, the toughness after curing is improved as compared with the conventional bismaleimide, and the mechanical strength of the cured product is high. In addition, since the structure is extremely symmetric and the rigid straight chain is bound by a bent chain, the orientation of the molecules is high, the higher order structure formed is dense, and has excellent thermal conductivity.

  Since the bismaleimide of the present invention is excellent in heat resistance, thermal conductivity, moisture resistance, mechanical strength, electrical insulation, and molding processability, it is a sealing material, substrate material, adhesive material, display material, recording material, and heat dissipation. It is useful as a raw material for materials, and its industrial value is extremely high.

  With the heat dissipation material of the present invention, it has become possible to provide parts and members for electrical and electronic equipment that are required to have particularly high heat resistance and thermal conductivity. Specifically, circuit board materials, sealing materials such as resistors / inductors / capacitors or cases for electronic components, sealing materials for IC / power transistor elements, light bulbs used in lighting equipment, LEDs, semiconductor lasers, etc. Sealing materials and base substrate materials for light emitting devices, automobile parts such as notebook PCs and mobile phones, lamp reflectors, motor casings for motor cores, motor parts such as casings, and sliding parts such as bearing members It has become possible to provide cooling parts such as radiating fins, heat sinks and heat pipes, heat exchanger parts, OA / communication equipment parts such as copier roller members, and the like.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to these examples in any way. The reagents listed below were manufactured by Wako Pure Chemical Industries, Ltd. unless otherwise specified.

[Evaluation methods]
Melting point measurement: Differential scanning calorimetry (manufactured by Perkin Elmer Japan Co., Ltd .; Pyris 1 DSC), temperature rising rate: 5 ° C./min. The temperature at the peak top of the endotherm was taken as the melting point.
Thermal conductivity evaluation: The thermal conductivity was evaluated using a steady-state thermal conductivity measuring device (GH-1 manufactured by ULVAC-RIKO).
Moisture absorption rate: The moisture absorption rate was evaluated from the change in weight of the test piece after 85 ° C. and 85% RH for 72 hours.
Mechanical strength evaluation: Bending strength was evaluated according to JIS-K6911.

[Synthesis Example 1 (Production of 4,4 ′-[1,6-hexanediylbis (oxy)] bisphenol)]
A container equipped with a stirrer, a reflux condenser, a dropping funnel, and a nitrogen introducing tube was charged with 1 kg of ethanol, 616.62 g of hydroquinone (manufactured by Tokyo Chemical Industry Co., Ltd.), and 1.49 g of sodium hyposulfite. While stirring this, 170.78 g of dibromohexane was added, the temperature was raised, and the mixed solution was refluxed. A solution was separately prepared from 117.82 g of potassium hydroxide and 500 g of ethanol, and was gradually added dropwise to the above mixed solution using a dropping funnel. Refluxing was continued for 8 hours while stirring, and then cooled to room temperature. Sulfuric acid diluted to 30 wt% was added to make the reaction solution acidic, and then 500 mL of ethanol was added to separate the white precipitate. The white precipitate is washed once with hot ethanol, then washed three times with distilled water, and dried at 80 ° C. under reduced pressure to give 4,4 ′-[1,6-hexanediylbis (oxy)] bisphenol as a white solid. Got. Yield: 146.81 g (69%)

[Synthesis Example 2 (Production of 4-maleimidobenzoyl chloride)]
4-Maleimidobenzoyl chloride was synthesized by a known method described in Non-Patent Document 1 (Macromol. Chem. Phys., No. 17, 201 (2000)).

[Synthesis Example 3 (Production of Bismaleimide BMI-1)]
A vessel equipped with a stirrer, reflux condenser and nitrogen inlet tube was charged with 30.24 g of 4,4 ′-[1,6-hexanediylbis (oxy)] bisphenol (synthetic product), 12.65 g of triethylamine and 500 g of THF. And stirred. While cooling in an ice-water bath, 70.68 g of 4-maleimidobenzoyl chloride (synthetic product) was gradually charged. The ice-water bath was removed, the temperature was raised to room temperature, and stirring was continued for 24 hours. The resulting dark brown suspension was filtered and the brown precipitate was filtered off. This brown precipitate was washed 3 times with distilled water and dried at 100 ° C. using a vacuum dryer to obtain a brown solid bismaleimide (hereinafter abbreviated as BMI-1).

Yield: 49.5 g (70%)
Melting point: 145.8 ° C
¹ H-NMR (270 MHz, CDCl ₃ ): δ 8.29 (4H, d, aromatic), 7.58 (4H, d, aromatic), 7.12 (4H, d, aromatic), 6.93 (4H, d, aromatic), 6.90 (4H, s, _{unsaturated), 3.99 (4H, br,} CH 2), 1.84 (4H, br, CH 2), 1.56 (4H , Br, CH ₂ )

Examples 1 to 5 [Production of resin composition and heat dissipation material]
BMI-1 and BMI-2, BMI-3, and BMI-4 having the structure shown in Table 1 were synthesized, dicumyl peroxide (manufactured by Sigma Aldrich Japan Co., Ltd .; hereinafter referred to as DCPO), and aluminum nitride powder (Mitsui). Chemical Co., Ltd .; average particle size 15 μm, porosity 0.1%, sphericity 0.96) were added in the composition shown in Table 1 and mixed uniformly. A heat press machine (Mini Test Press MP-S manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used for producing the heat dissipation material. The resin composition was charged into a mold at room temperature and cured by heating at 180 ° C. for 7 hours to produce a plate-like heat dissipation material having a thickness of 1 mm. The results are shown in Table 1.

Comparative Example 1 [Production of cured bismaleimide (BMI-0) resin]
In place of BMI-1, bis (4-maleimidophenyl) methane (synthetic product; hereinafter abbreviated as BMI-0), which is a known bismaleimide, was used in the same manner as in Example 1 to obtain a 1 mm thickness. A plate-like cured bismaleimide resin was produced. The results are shown in Table 1.

Comparative Examples 2-3 [Production of cured epoxy resin]
4- (oxiranylmethoxy) benzoic acid-4,4 '-[1,6-hexanediylbis (oxy)] bisphenol ester (synthetic product; hereinafter referred to as EP-1), which is a known epoxy resin monomer , 4,4'-diaminodiphenyl ether (hereinafter abbreviated as DDE) g, and aluminum nitride powder (Mitsui Chemicals, Inc .; average particle size 15 μm, porosity 0.1%, sphericity 0.96) 1 was added and mixed uniformly, and this was charged into a mold and cured by heating at 160 ° C. for 10 hours to produce a cured epoxy resin having a thickness of 1 mm. The results are shown in Table 1.

The heat-dissipating material of the present invention is used to promote heat dissipation from a heat-generating part or a high-temperature part of an electric / electronic device. Particularly, parts / members that require high heat resistance and heat conductivity, specifically, circuit board materials, Sealing materials for resistors, inductors, capacitors, etc. or cases for electronic components, sealing materials for IC / power transistor devices, sealing materials for light emitting devices such as light bulbs, LEDs, semiconductor lasers, and bases used in lighting equipment, etc. Substrate materials, notebook PC / mobile phone casings, automotive parts such as lamp reflectors, motor casings for motor cores, motor parts such as casings, sliding parts such as bearing members, radiating fins, heat sinks, heat pipes, etc. OA / communication equipment parts such as cooling parts, heat exchanger parts, and copier roller members can be provided.

Claims (6)

A heat dissipation material containing at least a cured product of bismaleimide represented by the general formula (I).
(In the formula, I represents a maleimide group, M represents a mesogenic group, and S represents a spacer.) A heat dissipation material containing at least a cured product of bismaleimide represented by the general formula (II).
(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y and z represents a divalent substituent composed are each independently a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO _{-, - CO-O -,} - CO-NH -, - C (CH 3) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O A divalent substituent selected from the group of N). Furthermore, the thermal radiation material in any one of Claim 1 or 2 which contains an inorganic filler. The inorganic filler is at least one selected from aluminum oxide, aluminum nitride, aluminum fluoride, calcium fluoride, silica, silicon nitride, silicon carbide, boron nitride, magnesium oxide, beryllium oxide, tin oxide, graphite, carbon fiber, and diamond. The heat dissipating material according to claim 3. A resin composition containing at least a bismaleimide represented by the general formula (II).
(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y showing a divalent substituent composed of a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-NH _{-, - C (CH 3)} = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 valent selected from the group consisting of N- It represents a substituent, z is a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-O -, - C _{-NH -, - C (CH 3} ) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 selected from the group consisting of N- A valent substituent.) A bismaleimide represented by the general formula (III).
(In the formula, A ₁ and A ₂ each independently represent a divalent substituent selected from an aromatic group, a condensed aromatic group, and an alicyclic heterocyclic group, or a direct bond, provided that A ₁ and A ₂ is not a direct bond at the same time, and x is 2 to 20 atomic groups represented by a combination selected from the group of —CH ₂ —, —Si (CH ₃ ) ₂ —, or —O—. .y showing a divalent substituent composed of a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-NH _{-, - C (CH 3)} = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 valent selected from the group consisting of N- .z illustrating a substituent, a direct _{bond, -O -, - CH 2 -CH} 2 -, - CH = CH -, - C≡C -, - CO -, - CO-O -, - C _{-NH -, - C (CH 3} ) = CH -, - CH = N -, - CH = N-N = CH -, - N = N- or -N (O) = 2 selected from the group consisting of N- A valent substituent.)