JP2014024959A - Metal resin composite having excellent heat radiation effect - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal resin composite exhibiting excellent heat radiation properties.SOLUTION: A metal resin composite is produced by arranging a metallic member in the inner part of mold and forming a resin molding part on at least a part of surface of the metallic member and a thermoplastic resin which forms the resin molding part contains 25 to 60 mol% of (A) a unit having a biphenyl group, 25 to 60 mol% of (B) a linear unit (such as a linear aliphatic hydrocarbon chain) and 0 to 25 mol% of (C) a unit having a substituent selected from an aromatic group, a condensed aromatic group, a heterocyclic group, an alicyclic group and a cycloaliphatic heterocyclic group having folding effects of a major chain and has a thermal conductivity in a single resin of 0.4 W/(m K) or more.

Description

  The present invention relates to a heat dissipation material having excellent heat conductivity, and relates to a metal-resin composite having excellent heat dissipation.

  When a thermoplastic resin composition is used in various applications such as PC and display housings, electronic device materials, and interior and exterior of automobiles, the heat generated due to the low thermal conductivity of plastics compared to inorganic materials such as metal materials. Difficult to escape may be a problem.

  As one method for solving such a problem, a technique for integrating a metal and a resin excellent in heat dissipation has been developed. Patent Document 1 describes that a metal surface is finely roughened by dipping in a special chemical solution to improve the adhesion and adhesive strength between the metal and the resin.

  Further, in Patent Documents 2 and 3, by combining a metal surface-treated with a triazine compound and a thermoplastic resin having a thioether bond or an amide bond, the adhesive strength between the metal and the resin composition, heat resistance Describes a method for obtaining a metal resin composite excellent in heat dissipation and heat dissipation. However, in any case, since the thermal conductivity in the thickness direction of the thermoplastic resin composition itself is low, there is a problem that heat from the heating element cannot be efficiently transferred to the metal.

  As a method of improving the thermal conductivity in the thickness direction of the resin composition, there is a method of blending a large amount of highly heat-conductive inorganic substance in a thermoplastic resin. In that case, high heat such as graphite, carbon fiber, alumina, boron nitride, etc. It is necessary to mix the conductive inorganic substance in the resin with a high content of usually 30 Vol% or more, and further 50 Vol% or more. However, even if a large amount of the inorganic substance is blended, the thermal conductivity of the resin alone is low, so that the thermal conductivity of the resin composition has a limit. Therefore, improvement in the thermal conductivity of the resin alone has been demanded.

  As for the thermoplastic resin with excellent thermal conductivity of the resin itself, there are almost no research reports on thermoplastic resins in which the resin itself molded by injection molding has high thermal conductivity without special molding processes such as stretching and magnetic field orientation. However, Patent Documents 4 to 6 are listed as few examples. As described in Patent Documents 4 to 6, the inventors of the present invention have found a thermoplastic resin and a resin composition that exhibit high thermal conductivity with a single resin. Although the thermoplastic resin described in Patent Documents 4 to 6 can obtain a molded article exhibiting excellent thermal conductivity by injection molding, there is no description about the composite of metal and resin.

JP2008-173967 JP2009-185102A JP 2009-202567 A International Publication Number WO2010 / 050202 Japanese Patent Application No. 2011-024739 International Publication Number WO2011 / 033815

An object of the present invention is to provide a metal resin composite exhibiting excellent heat dissipation by integrally molding a resin composition comprising a thermoplastic resin having excellent thermal conductivity in the thickness direction and a metal. .

When the present inventors have molded a thermoplastic resin that is a polycondensate having a specific molecular structure, the thermal conductivity in the thickness direction is further increased. Therefore, when a metal and a resin are combined, the resin is converted into a metal. The present inventors have found that the heat of the heat can be transferred more efficiently, and have reached the present invention. That is, the present invention includes the following 1) to 12).
1)
A metal-resin composite obtained by disposing a metal member inside a mold and forming a resin molded portion on at least a part of the surface of the metal member, the thermoplastic resin forming the resin molded portion The structure of the main chain is general formula (1)

(Wherein X represents a divalent substituent selected from the group of O and CO)
Unit (A) having a biphenyl group represented by 25 to 60 mol%,
General formula (2)
-YR-Y- (2)
(In the formula, R represents a divalent linear substituent which may contain a branch having 2 to 20 main chain atoms. Y represents a divalent substituent selected from the group of O and CO.)
Unit (B) represented by 25 to 60 mol%,
General formula (3)
-Z ¹ -MZ ^2- (3)
(In the formula, Z ¹ and Z ² represent a divalent substituent selected from the group of O, NH, CO, S and NHCO. M represents an aromatic group having a main chain folding effect, a condensed aromatic group, A substituent selected from a heterocyclic group, an alicyclic group, and an alicyclic heterocyclic group is shown.)
Unit (C) represented by 0 to 25 mol% (however, the total of units (A), (B), and (C) is 100 mol%), and the thermal conductivity of the resin alone is 0.4 W / (M * K) The metal resin composite which consists of a thermoplastic resin composition which is more than.
2)
The metal resin composite as described in 1), wherein 60 mol% or more of molecular chain terminals of the thermoplastic resin are carboxyl groups.
3)
The metal resin composite according to 1) or 2), wherein X in the general formula (1) is O and Y in the general formula (2) is CO.
4)
The metal resin composite according to any one of 1) to 3), wherein a portion corresponding to R of the thermoplastic resin is a linear aliphatic hydrocarbon chain.
5)
The metal resin composite according to any one of 1) to 4), wherein the number of main chain atoms in a portion corresponding to R of the thermoplastic resin is an even number.
6)
R in the thermoplastic resin is at least one selected from — (CH ₂ ) ₈ —, — (CH ₂ ) ₁₀ —, and — (CH ₂ ) ₁₂ —, 1) to 5) Metal resin composite.
7)
The metal resin composite according to any one of 1) to 6), wherein M of the thermoplastic resin is any one of the structures shown below.

8)
The metal resin composite according to any one of 1) to 7), wherein the thermoplastic resin has a number average molecular weight of 3000 to 40000.
9)
The metal resin composite according to any one of 1) to 8), wherein the ratio of lamellar crystals in the thermoplastic resin is 10 Vol% or more.
10)
A metal resin composite comprising an inorganic filler having a thermal conductivity of 1 W / (m · K) or more as a single substance in the thermoplastic resin composition.
11)
The inorganic filler is one or more electrically insulating high heat selected from the group consisting of boron nitride, aluminum nitride, silicon nitride, aluminum oxide, magnesium oxide, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, beryllium oxide and diamond. 10. The metal resin composite as described in 10), which is a conductive inorganic compound.
12)
The inorganic filler is one or more conductive high thermal conductive inorganic compounds selected from the group consisting of graphite, conductive metal powder, soft magnetic ferrite, carbon fiber, conductive metal fiber, and zinc oxide. 11) The metal resin composite according to 11).
13)
It is a structure having the metal resin composite according to any one of 1) to 12) and a heating element, wherein the thermoplastic resin composition is present between the heating element and the metal of the metal resin composite. Characteristic structure.

The metal resin composite of the present invention is excellent in thermal conductivity and exhibits excellent heat dissipation.

Metal resin composite Metal resin composite Metal resin composite Test specimen for evaluation Structure Structure Structure

  The present invention provides a metal-resin composite in which a metal member is disposed inside a mold and a resin molded part is formed on at least a part of the surface of the metal member, the heat forming the resin molded part The structure of the main chain of the plastic resin is the general formula (1)

(Wherein X represents a divalent substituent selected from the group of O and CO)
Unit (A) having a biphenyl group represented by 25 to 60 mol%,
General formula (2)
-YR-Y- (2)
(In the formula, R represents a divalent linear substituent which may contain a branch having 2 to 20 main chain atoms. Y represents a divalent substituent selected from the group of O and CO.)
Unit (B) represented by 25 to 60 mol%,
General formula (3)
-Z ¹ -MZ ^2- (3)
(In the formula, Z ¹ and Z ² represent a divalent substituent selected from the group of O, NH, CO, S and NHCO. M represents an aromatic group having a main chain folding effect, a condensed aromatic group, A substituent selected from a heterocyclic group, an alicyclic group, and an alicyclic heterocyclic group is shown.)
The unit (C) is represented by 0 to 25 mol% (however, the sum of the units (A), (B), and (C) is 100 mol%), and the thermal conductivity of the resin alone is 0.4 W / (m · K) or more.

  The thermoplasticity referred to in the present invention is a property of being plasticized by heating, and the thermoplastic resin of the present invention is preferably such that the unit (A) is 30 to 55 mol% and the unit (B) is 30. It is -55 mol%, and is a thermoplastic resin whose unit (C) is 0-20 mol%. More preferably, it is a thermoplastic resin in which the unit (A) is 30 to 48%, the unit (B) is 45 to 55 mol%, and the unit (C) is 0 to 15 mol%. The ratio of units (A), (B), and (C) is 30-55 mol% for unit (A), 30-55 mol% for unit (B), and 1 for unit (C). -20 mol% is also preferable, unit (A) is 30-48%, unit (B) is 45-55 mol%, and unit (C) is more preferably 1-15 mol%. When the unit (C) is 26 mol% or more, the thermal conductivity may decrease.

  The thermal conductivity of the thermoplastic resin of the present invention is 0.4 W / (m · K) or more, preferably 0.6 W / (m · K) or more, more preferably 0.8 W / (m · K). ) Or more, and particularly preferably 1.0 W / (m · K) or more. The upper limit of the thermal conductivity is not particularly limited and is preferably as high as possible, but generally 30 W / (m · K) or less unless physical treatment such as magnetic field, voltage application, rubbing, and stretching is performed during molding. Further, it becomes 10 W / (m · K) or less.

  The metal member of the present invention is a metal or an alloy (hereinafter collectively referred to as “metal”). The material of the metal is not particularly limited, but aluminum and an alloy including the same (aluminum alloy), copper and an alloy including the same (brass, bronze, aluminum brass, etc.), nickel, chromium, titanium, iron, cobalt, tin, zinc, Palladium, silver, stainless steel, magnesium, manganese etc. are mentioned.

  The shape of the metal member is not particularly limited, and examples thereof include a flat plate shape, a curved plate shape, a rod shape, a cylindrical shape, and a lump shape, and may be a structure formed by a combination thereof. Moreover, you may have a through-hole, a bending part, etc.

  The surface shape of the metal member on which the resin molded portion of the present invention is formed is not particularly limited, and examples thereof include a flat plate, a curved surface, an uneven surface, and a pointed portion. As described above, the resin molded portion may be formed on a part of the surface of the metal member or on the entire surface.

  The surface of the metal member on which the resin molded part is formed may be subjected to a surface treatment from the viewpoints of adhesive strength and adhesion between the metal member and the resin molded part. The surface treatment method is not particularly limited, and examples thereof include fine chemical roughening by special chemicals and physical polishing, anodization, and formation of a film by an organic compound.

  Although the molding method of the metal resin composite of the present invention is not particularly limited, an injection molding method is preferable from the viewpoint of easy moldability.

  The thermoplastic resin in the present invention exhibits liquid crystallinity and has a liquid crystal phase transition temperature and an isotropic phase transition temperature. The resin temperature of the thermoplastic resin composition to be introduced into the mold is not particularly limited as long as it is equal to or higher than the solidification temperature, but the liquid crystal phase transition temperature and the isotropic phase transition can be expressed in that higher thermal conductivity can be expressed. It is preferable to mold in a liquid crystal state by heating to a temperature between temperatures. The liquid crystal phase transition temperature and the isotropic phase transition temperature referred to here are the low-temperature side and the high-temperature side, respectively, of two peaks observed in the temperature rising process in differential scanning calorimetry (DSC). The temperature of the mold is not particularly limited, but is preferably 40 ° C to 190 ° C. From the viewpoint of moldability, 100 to 180 ° C. is more preferable.

  In the metal member of the present invention, the presence or absence of preheating at the time of molding is not particularly limited, but it is preferably preheated from the viewpoint of formability.

  The ratio of the carboxyl group with respect to all terminals of the molecular chain of the thermoplastic resin of the present invention is preferably 60 mol% or more, more preferably 70 mol% or more, and further preferably 80 mol% or more. When the amount is less than 60 mol%, the thermal conductivity of the resin composition may be lower than that of a resin having a terminal carboxyl group of 60 mol% or more when an inorganic filler is blended.

The thermoplastic resin of the present invention is
General formula (1)

(Wherein X represents a divalent substituent selected from the group of O and CO)
X in the inside is preferably O from the viewpoint of obtaining a resin having excellent thermal conductivity.

General formula (2)
-YR-Y- (2)
(In the formula, R represents a divalent linear substituent which may contain a branch having 2 to 20 main chain atoms. Y represents a divalent substituent selected from the group of O and CO.)
Y in the inside is preferably CO from the viewpoint that a resin having excellent thermal conductivity can be obtained.

R in the general formula (2) represents a divalent linear substituent which may include a branch having 2 to 20 main chain atoms, and is a linear aliphatic hydrocarbon chain not including a branch. preferable. When branching is included, the crystallinity may be reduced, and the thermal conductivity may be reduced. R may be saturated or unsaturated, but is preferably a saturated aliphatic hydrocarbon chain. When the unsaturated bond is included, sufficient flexibility cannot be obtained, and the thermal conductivity may be lowered. R is preferably a straight chain saturated aliphatic hydrocarbon chain having 2 to 20 carbon atoms, more preferably a straight chain saturated aliphatic hydrocarbon chain having 4 to 18 carbon atoms, particularly 8 to 8 carbon atoms. Preferably, it is a 14 straight chain saturated aliphatic hydrocarbon chain. The number of main chain atoms of R is preferably an even number. In the case of an odd number, the crystallinity may decrease and the thermal conductivity may decrease. In particular, R is preferably at least one selected from — (CH ₂ ) ₈ —, — (CH ₂ ) ₁₀ —, and — (CH ₂ ) ₁₂ — from the viewpoint that a resin having excellent thermal conductivity can be obtained. .

General formula (3)
-Z ¹ -MZ ^2- (3)
(In the formula, Z ¹ and Z ² represent a divalent substituent selected from the group of O, NH, CO, S and NHCO. M represents an aromatic group having a main chain folding effect, a condensed aromatic group, A substituent selected from a heterocyclic group, an alicyclic group, and an alicyclic heterocyclic group is shown.)
The main chain folding effect referred to here means the effect of bending the polymer main chain so as to fold, and the angle between the bonds forming the main chain is 150 degrees or less, preferably 120 degrees or less, more preferably It is 60 degrees or less. Specific examples of M in the general formula (3) include groups represented by the following.

From the viewpoint of obtaining a resin having excellent thermal conductivity, specific examples of M in the general formula (3) include groups represented by the following.

Further, from the viewpoint of obtaining a resin having excellent thermal conductivity, a group represented by the following is more preferable.

Z ^1, Z ² in formula (3) is O, NH, CO, S, from the viewpoint represents a divalent substituent selected from the group consisting of NHCO, thermal conductivity and excellent resin is obtained, Z ¹ , Z ² is preferably any of O, NH, and CO, and more preferably both Z ¹ and Z ² are O.
The number average molecular weight of the thermoplastic resin in the present invention is based on polystyrene, and the thermoplastic resin in the present invention is dissolved in a mixed solvent of p-chlorophenol and toluene in a volume ratio of 3: 8 so as to have a concentration of 0.25% by weight. It is the value measured at 80 ° C. by GPC using the prepared solution. The number average molecular weight of the thermoplastic resin in the present invention is preferably 3000 to 40000, more preferably 5000 to 30000, and still more preferably 7000 to 20000. When the number average molecular weight is less than 3000 or greater than 40000, even if the resin has the same primary structure, the thermal conductivity may be less than 0.6 W / (m · K).

 The thermoplastic resin according to the present invention may be produced by any known method. From the viewpoint that the control of the structure is simple, a compound having a reactive functional group at both ends of the biphenyl group, a compound having a reactive functional group at both ends of the linear substituent R, and the main chain folding effect A method in which a substituent M having a hydrogen atom is reacted with a compound having two reactive functional groups is preferred. As such a reactive functional group, known ones such as a hydroxyl group, a carboxyl group, an ester group, an amino group, a thiol group, and an isocyanate group can be used, and the conditions for reacting them are not particularly limited.

  From the viewpoint of easy synthesis, a combination of a compound having a reactive functional group at both ends of the biphenyl group and a compound having a reactive functional group at both ends of the linear substituent R is Both a compound having a hydroxyl group at the end, a compound having a carboxyl group at both ends of the linear substituent R, or a compound having a carboxyl group or an ester group at both ends of the biphenyl group, and both of the linear substituent R A combination of compounds having a hydroxyl group at the terminal is preferred. In addition, for a compound having two reactive functional groups in the substituent M having a main chain folding effect, the substituent M having a main chain folding effect has at least one of a hydroxyl group, a carboxyl group, an ester group, and an amino group. It is preferable to have one.

  A thermoplastic resin comprising a compound having a hydroxyl group at both ends of a biphenyl group, a compound having a carboxyl group at both ends of a linear substituent R, and a compound having a hydroxyl group at a substituent M having a main chain folding effect As an example of the production method, the hydroxyl group of the compound is individually or collectively converted into a lower fatty acid ester using a lower fatty acid such as acetic anhydride, and then substituted with a straight chain in another reaction vessel or the same reaction vessel. Examples include a method in which a compound having a carboxyl group at both ends of the group R is subjected to a delowering fatty acid polycondensation reaction. The polycondensation reaction is carried out at a temperature of usually 220 to 330 ° C., preferably 240 to 310 ° C. in the presence of substantially no solvent, in the presence of an inert gas such as nitrogen, at normal pressure or reduced pressure, and at a pressure of 0. 5 to 5 hours. When the reaction temperature is lower than 220 ° C, the reaction proceeds slowly, and when it is higher than 330 ° C, side reactions such as decomposition tend to occur. When making it react under reduced pressure, it is preferable to raise a pressure reduction degree in steps. When the pressure is rapidly reduced to a high degree of vacuum, the monomer having the linear substituent R and the monomer having the main chain folding effect volatilize, and a resin having a desired composition or molecular weight may not be obtained. The ultimate vacuum is preferably 40 Torr or less, more preferably 30 Torr or less, further preferably 20 Torr or less, and particularly preferably 10 Torr or less. When the degree of vacuum is higher than 40 Torr, deoxidation does not proceed sufficiently and a low molecular weight resin may be obtained. A multi-stage reaction temperature may be employed. In some cases, the reaction product can be withdrawn in a molten state and recovered as soon as the temperature rises or when the maximum temperature is reached. The obtained thermoplastic resin may be used as it is, or unreacted raw materials may be removed, or solid phase polymerization may be performed in order to increase physical properties. When solid phase polymerization is performed, the obtained thermoplastic resin is mechanically pulverized into particles having a particle size of 3 mm or less, preferably 1 mm or less, and inert such as nitrogen at 100 to 350 ° C. in a solid state. The treatment is preferably performed in a gas atmosphere or under reduced pressure for 1 to 30 hours. If the particle size of the polymer particles is larger than 3 mm, the treatment is not sufficient, and problems with physical properties are caused, which is not preferable. It is preferable to select the treatment temperature and the rate of temperature increase during solid phase polymerization so that the thermoplastic resin particles do not cause fusion.

  Examples of the acid anhydride of the lower fatty acid used in the production of the thermoplastic resin in the present invention include acid anhydrides of lower fatty acids having 2 to 5 carbon atoms, such as acetic anhydride, propionic anhydride, monochloroacetic anhydride, dichloroacetic anhydride, Trichloroacetic anhydride, monobromoacetic anhydride, dibromoacetic anhydride, tribromoacetic anhydride, monofluoroacetic anhydride, difluoroacetic anhydride, trifluoroacetic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, pivalic anhydride, etc. Acetic anhydride, propionic anhydride, and trichloroacetic anhydride are particularly preferably used. The amount of the lower fatty acid anhydride used is 1.01 to 1.5 times equivalent, preferably 1.02 to 1.2 times equivalent to the total of hydroxyl groups and amino groups of the monomers used. When the amount is less than 1.01 equivalent, the lower fatty acid anhydride may volatilize, whereby the hydroxyl group and amino group may not completely react with the lower fatty acid anhydride, and a low molecular weight resin may be obtained. is there. In addition, a compound having a carboxyl group or an ester group at both ends of the biphenyl group, a compound having a hydroxyl group at both ends of the substituent R, and a compound having a carboxyl group or an ester group at the substituent M having a main chain folding effect As a method for producing a thermoplastic resin comprising, for example, a method of melt polymerization of dimethyl 4,4′-biphenyldicarboxylate and an aliphatic diol as described in JP-A-2-258864 is mentioned.

  You may use a catalyst for manufacture of the thermoplastic resin of this invention. As the catalyst, conventionally known polyester polymerization catalysts can be used, such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, antimony trioxide and the like. Mention may be made of organic compound catalysts such as metal salt catalysts, N, N-dimethylaminopyridine, N-methylimidazole and the like.

The amount of the catalyst added is usually 1 × 10 ⁻³ to 1% by weight, preferably 5 × 10 ^{−3 to} 5 × 10 ⁻¹ % by weight, more preferably 1 × based on the total weight of the thermoplastic resin. 10 ⁻² to 1 × 10 ⁻¹ wt% is used.

  Although the terminal structure of the thermoplastic resin of the present invention is not particularly limited, from the viewpoint of obtaining a resin suitable for molding, a hydroxyl group, a carboxyl group, an ester group, an acyl group, an alkoxy group, an amino group, an amide group, a thiol group, It is preferable that the terminal is sealed with an isocyanate group or the like. When the terminal has a highly reactive functional group such as an epoxy group or a maleimide group, the resin becomes thermosetting and the injection moldability may be impaired. From the viewpoint of exhibiting high thermal conductivity, the terminal structure is particularly preferably a carboxyl group. The ratio of the carboxyl group with respect to all terminals of the molecular chain is 60 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more. When it is less than 60 mol%, when an inorganic filler is blended, the thermal conductivity of the resin composition may be lower than that of a resin having a terminal carboxyl group of 60 mol% or more.

 In this invention, it is preferable that the ratio of the lamellar crystal in a thermoplastic resin is 10 Vol% or more. The ratio of lamellar crystals is preferably 20 Vol% or more, more preferably 30 Vol% or more, and particularly preferably 40 Vol% or more.

  The lamellar crystal referred to in the present invention corresponds to a plate-like crystal in which long chain molecules are folded and arranged in parallel. There exists a tendency for the heat conductivity of a thermoplastic resin and a resin composition to become high, so that the ratio of a lamellar crystal is high. Whether or not lamellar crystals are present in the resin can be easily determined by observation with a transmission electron microscope (TEM) or X-ray diffraction.

The ratio of lamellar crystals can be calculated by directly observing a sample stained with RuO ₄ with a transmission electron microscope (TEM). As a specific method, a sample for TEM observation was prepared by cutting out a part of a molded cylindrical sample having a thickness of 6 mm × 20 mmφ, staining with RuO ₄ , and then forming a 0.1 μm-thick ultrathin slice with a microtome. Shall be used. The prepared slice is observed with a TEM at an accelerating voltage of 100 kV, and the region of the lamellar crystal can be determined from the obtained 40,000-fold scale photograph (18 cm × 25 cm). The boundary of the region can be determined by using the lamellar crystal region as a region where periodic contrast exists. Since the lamella crystals are similarly distributed in the depth direction, the ratio of the lamella crystals can be calculated as a ratio of the lamella crystal region to the entire area of the photograph.

  The thermal conductivity of the thermoplastic resin composition of the present invention is preferably 0.4 W / (m · K) or more, more preferably 1.0 W / (m · K) or more, and even more preferably 5.0 W / (M · K) or more, particularly preferably 10 W / (m · K) or more. When the thermal conductivity is less than 0.4 W / (m · K), it is difficult to efficiently transmit the heat generated from the electronic component to the outside. The upper limit of the thermal conductivity is not particularly limited, and is preferably as high as possible. Generally, a thermal conductivity of 100 W / (m · K) or less, further 80 W / (m · K) or less is used. Since the thermoplastic resin used in the present invention has excellent thermal conductivity, it is possible to easily obtain a highly thermally conductive thermoplastic resin composition having a thermal conductivity in the above range.

  The amount of the inorganic filler used in the thermoplastic resin composition of the present invention is preferably 90:10 to 30:70, more preferably 80:20 to 40:60, by volume ratio of the thermoplastic resin and the inorganic filler. And particularly preferably 70:30 to 50:50. If the volume ratio of the thermoplastic resin to the inorganic filler is 100: 0 to 90:10, satisfactory thermal conductivity may not be obtained. When the volume ratio of the thermoplastic resin to the inorganic filler is 30:70 to 10:90, the mechanical properties may be lowered. Since the thermoplastic resin of the present invention has excellent thermal conductivity, the resin composition can be used even when the amount of the inorganic filler used is as small as 90:10 to 70:30 in the volume ratio of the thermoplastic resin to the inorganic filler. Has excellent thermal conductivity, and at the same time, the density can be lowered due to the small amount of inorganic filler used. The excellent thermal conductivity and low density are advantageous when used as a heat-dissipating / heat-transfer resin material in various situations such as in the electric / electronic industry and automobile fields.

  A wide variety of known fillers can be used as the inorganic filler. The thermal conductivity of the inorganic filler alone is preferably 1 W / (m · K) or more, more preferably 10 W / (m · K) or more, further preferably 20 W / (m · K) or more, particularly preferably 30 W / The thing more than (m * K) is used. The upper limit of the thermal conductivity of the inorganic filler alone is not particularly limited, and it is preferably as high as possible. Generally, it is 3000 W / (m · K) or less, more preferably 2500 W / (m · K) or less. Preferably used.

  When the resin composition is used for applications that do not require electrical insulation, a metal compound, a conductive carbon compound, or the like is preferably used as the inorganic filler. Among these, since it is excellent in thermal conductivity, conductive carbon materials such as graphite and carbon fibers, conductive metal powders obtained by atomizing various metals, conductive metal fibers obtained by processing various metals into fibers, soft magnetic ferrite Inorganic fillers such as various ferrites such as zinc oxide and metal oxides such as zinc oxide can be suitably used.

When the resin composition is used for applications requiring electrical insulation, a compound showing electrical insulation is suitably used as the inorganic filler. Specifically, the electrical insulating property indicates an electrical resistivity of 1 Ω · cm or more, preferably 10 Ω · cm or more, more preferably 10 ⁵ Ω · cm or more, and further preferably 10 ¹⁰ Ω · cm or more. It is preferable to use a material having a thickness of cm or more, most preferably 10 ¹³ Ω · cm or more. The upper limit of the electrical resistivity is not particularly limited, but is generally 10 ¹⁸ Ω · cm or less. It is preferable that the electrical insulation of the molded product obtained from the high thermal conductivity thermoplastic resin composition of the present invention is also in the above range.

  Among inorganic fillers, specific examples of compounds that exhibit electrical insulation include metal oxides such as aluminum oxide, magnesium oxide, silicon oxide, beryllium oxide, copper oxide, and cuprous oxide, boron nitride, aluminum nitride, and nitride. Examples thereof include metal nitrides such as silicon, metal carbides such as silicon carbide, metal carbonates such as magnesium carbonate, insulating carbon materials such as diamond, and metal hydroxides such as aluminum hydroxide and magnesium hydroxide. These can be used alone or in combination.

  The shape of the inorganic filler is not particularly limited. For example, particles, fine particles, nanoparticles, aggregated particles, tubes, nanotubes, wires, rods, needles, plates, irregular shapes, rugby balls, hexahedrons, large particles and fine particles are combined Although various shapes such as a composite particle shape and a liquid are mentioned, an inorganic filler such as a true spherical shape, a round shape, and an aggregated particle shape is more preferable in that the heat dissipation effect of the present invention can be further improved. By using the inorganic filler of these shapes, the thermal conductivity in the thickness direction of the resin composition can be further improved, and the heat from the heating element can be efficiently transferred to the metal. Specific examples of the inorganic filler having the above shape include magnesium oxide, aluminum oxide, boron nitride, and aluminum nitride. Although it does not specifically limit as addition amount, As a addition amount increases, the thermal radiation effect can be improved more. The inorganic filler may be a natural product or a synthesized one. In the case of a natural product, there are no particular limitations on the production area and the like, which can be selected as appropriate. These inorganic fillers may be used alone or in combination of two or more different shapes, average particle diameters, types, surface treatment agents and the like.

  These inorganic fillers may have been subjected to surface treatment with various surface treatment agents such as a silane treatment agent in order to enhance the adhesion at the interface between the resin and the inorganic compound or to facilitate workability. . It does not specifically limit as a surface treating agent, For example, conventionally well-known things, such as a silane coupling agent and a titanate coupling agent, can be used. Among them, an epoxy group-containing silane coupling agent such as epoxy silane, an amino group-containing silane coupling agent such as aminosilane, polyoxyethylene silane, and the like are preferable because they hardly reduce the physical properties of the resin. The surface treatment method of the inorganic compound is not particularly limited, and a normal treatment method can be used.

  In the thermoplastic resin composition of the present invention, known fillers can be widely used in addition to the inorganic fillers according to the purpose. Since the thermal conductivity of the single resin is high, the resin composition has a high thermal conductivity even if the thermal conductivity of the known filler is relatively low as less than 10 W / (m · K). Examples of fillers other than inorganic fillers include diatomaceous earth powder, basic magnesium silicate, calcined clay, fine powder silica, quartz powder, crystalline silica, kaolin, talc, antimony trioxide, fine powder mica, molybdenum disulfide, Examples thereof include inorganic fibers such as rock wool, ceramic fibers, and asbestos, and glass fillers such as glass fibers, glass powder, glass cloth, and fused silica. By using these fillers, for example, it is possible to improve favorable characteristics in applying a resin composition such as thermal conductivity, mechanical strength, or abrasion resistance. Furthermore, if necessary, organic fillers such as paper, pulp, wood, polyamide fiber, aramid fiber, boron fiber and other synthetic fibers, polyolefin powder and the like can be used in combination.

  The present invention may be a structure having a metal resin composite and a heating element. In this structure, the thermoplastic resin composition is preferably present between the heating element and the metal of the metal resin composite. That is, it is preferable that the heating element and the metal are bonded via the thermoplastic resin composition, and the heating element and the metal are not directly bonded. In general, it can be said that the thermal conductivity of metal is considerably higher than that of resin. Therefore, in the conventional structures, there are relatively many structures in which the heating element and the metal are directly coupled for the purpose of increasing the heat radiation efficiency. However, depending on the application, it may be preferable that the heating element and the metal are not electrically coupled. The present invention is excellent as a structure in which a heating element and a metal are not directly bonded.

Since the thermoplastic resin composition of the metal resin composite of the present invention has a high thermal conductivity in the thickness direction, the heat from the heating element can be more efficiently transferred to the metal, and the heat dissipation effect is further improved. Can do. In addition, when the conductive inorganic filler is not used, the resin composition exhibits insulating properties, so that the electricity generated from the heating element can be insulated without being conducted to the metal.
The thermoplastic resin composition of the present invention includes an epoxy resin, a polyolefin resin, a bismaleimide resin, a polyimide resin, a polyether resin, a phenol resin, a silicone resin, a polycarbonate resin, and a polyamide as long as the effects of the present invention are not lost. Any known resin such as resin, polyester resin, fluorine resin, acrylic resin, melamine resin, urea resin, urethane resin may be contained. Specific examples of preferred resins include polycarbonate, polyethylene terephthalate, polybutylene terephthalate, liquid crystal polymer, nylon 6, nylon 6,6 and the like. The amount of these resins used is in the range of 0 to 10,000 parts by weight with respect to 100 parts by weight of the thermoplastic resin of the present invention usually contained in the resin composition.

  In the thermoplastic resin composition of the present invention, as an additive other than the above resin and filler, any other component, for example, a reinforcing agent, a thickener, a release agent, a coupling agent, a difficulty agent, or the like, depending on the purpose. A flame retardant, a flame retardant, a pigment, a colorant, other auxiliary agents, and the like can be added as long as the effects of the present invention are not lost. The amount of these additives used is preferably in the range of 0 to 20 parts by weight in total with respect to 100 parts by weight of the thermoplastic resin.

  It does not specifically limit as a manufacturing method of the thermoplastic resin composition of this invention. For example, it can be produced by drying the above-described components, additives and the like and then melt-kneading them in a melt-kneader such as a single-screw or twin-screw extruder. Moreover, when a compounding component is a liquid, it can also manufacture by adding to a melt-kneader on the way using a liquid supply pump etc.

  The metal resin composite of the present invention can be widely used in various applications such as electronic materials, magnetic materials, catalyst materials, structural materials, optical materials, medical materials, automobile materials, and building materials. In particular, it has excellent properties such as high thermal conductivity and heat dissipation, so it is very useful as a resin material for heat dissipation and heat transfer.

  The metal resin composite of the present invention can be suitably used for injection molded products such as home appliances, OA equipment parts, AV equipment parts, automobile interior and exterior parts, and the like. In particular, it can be suitably used in household electrical appliances and OA devices that generate a lot of heat. Furthermore, in an electronic device having a heat source inside but difficult to be forcibly cooled by a fan or the like, it is suitably used as an exterior material for these devices in order to dissipate the heat generated inside to the outside. Among these, preferable devices include portable computers such as notebook computers, PDAs, cellular phones, portable game machines, portable music players, portable TV / video devices, portable video cameras, and other small or portable electronic devices. It is very useful as a housing, a housing, etc. It can also be used very effectively as a resin for battery peripherals in automobiles, trains, etc., a resin for portable batteries in home appliances, a resin for power distribution parts such as breakers, and a sealing material for motors and the like.

The thermoplastic resin composition of the present invention can have a higher thermal conductivity in the thickness direction and better molding processability than conventionally known resins and resin compositions. It has characteristics useful as a part or casing for the above applications.

  Next, although the manufacture example, an Example, and a comparative example are given and demonstrated further in detail about the metal resin composite of this invention, this invention is not restrict | limited only to this Example. Unless otherwise specified, the reagents listed below were used without purification from Wako Pure Chemical Industries.

The raw material components used for preparing the resin composition are shown below.
Polyethylene terephthalate resin:
Novapex PBKII manufactured by Mitsubishi Chemical Corporation
Magnesium oxide:
RF-50-SC manufactured by Ube Material Co., Ltd., single body thermal conductivity 40 W / m · K, volume average particle diameter 50 μm, electrical insulation, volume resistivity 10 ¹⁴ Ω · cm
Boron nitride powder:
PT110 manufactured by Momentive Performance Materials Co., Ltd., single body thermal conductivity 60 W / m · K, volume average particle diameter 45 μm, electrical insulation, volume resistivity 10 ¹⁴ Ω · cm
Glass fiber:
T187H / PL manufactured by Nippon Electric Glass Co., Ltd., single body thermal conductivity 1.0 W / (m · K), fiber diameter 13 μm, number average fiber length 3.0 mm, electrical insulation, volume resistivity 10 ¹⁵ Ω · cm

[Evaluation method]
Number average molecular weight: A sample was prepared by dissolving the thermoplastic resin used in the present invention in a mixed solvent of p-chlorophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) and toluene in a volume ratio of 3: 8 to a concentration of 0.25% by weight. . The standard material was polystyrene, and a similar sample solution was prepared. The measurement was performed using a high temperature GPC (350 HT-GPC System manufactured by Viscotek) under conditions of a column temperature of 80 ° C. and a flow rate of 1.00 mL / min. A differential refractometer (RI) was used as a detector.

  Melting point: About 8 mg of the thermoplastic resin (A) was weighed, and heated at a rate of 20 ° C./min from 25 ° C. to 300 ° C. using a differential scanning calorimeter (manufactured by Shimadzu Corporation, DSC-50 ASSY). The temperature was lowered to 25 ° C., the temperature was raised again to 300 ° C. at a rate of 20 ° C./min, and an endothermic thermogram was measured.

Thermal conductivity: After the obtained pellet-shaped resin and resin composition were dried at 120 ° C. for 4 hours using a hot air dryer, an injection molding machine [manufactured by Toyo Machine Metal Co., Ltd., Si-15III] was used. Thickness
A disk-shaped sample of 1 mm × 26 mmφ was formed. Using the obtained sample, the thermal conductivity in the thickness direction and in-plane direction in the room temperature atmosphere was measured with a laser flash method thermal conductivity measuring device (LFA447 manufactured by NETZSCH).

  Quantification of terminal carboxyl group: Using 1H-NMR (400 MHz, deuterated chloroform: trifluoroacetic acid = 2: 1 vol% measured in a solvent), the ratio of the carboxyl group terminal is measured from the integral value of the characteristic signal of each terminal group. did. Table 1 shows chemical shift values of typical signals used for the measurement.

Percentage of lamella crystals: Sections cut out from an injection-molded 6 mm × 20 mmφ sample for observation, stained with RuO ₄ , and then 0.1 μm-thick ultrathin sections prepared with a microtome were subjected to TEM at an acceleration voltage of 100 kV. And observed. From the 40,000-fold scale photograph obtained by this TEM observation, the ratio of the lamellar crystal region was calculated as the ratio of the lamellar crystal region to the entire area of the photo.

[Production Example 1]
In a closed reactor equipped with a reflux condenser, a thermometer, a nitrogen introduction tube and a stir bar, 4,4′-dihydroxybiphenyl, sebacic acid, catechol, and acetic anhydride were each in a molar ratio of 0.9: 1.1: The mixture was charged at a ratio of 0.1: 2.1, and sodium acetate was used as a catalyst to react at 145 ° C. under atmospheric pressure and nitrogen atmosphere to obtain a uniform solution. Then, while acetic acid was distilled off at 2 ° C./min. The temperature was raised to 240 ° C., and the mixture was stirred at 240 ° C. for 30 minutes. Furthermore, it heated up to 260 degreeC at 1 degreeC / min, and stirred at 260 degreeC for 1 hour. Subsequently, while maintaining the temperature, the pressure was reduced to 10 Torr over about 40 minutes, and then the reduced pressure state was maintained. Three hours after the start of pressure reduction, the pressure was returned to normal pressure with nitrogen gas, and the produced polymer was taken out. Various data of the obtained resin are shown in Table 2. Let the obtained resin be (i).

[Production Example 2]
In a closed reactor equipped with a reflux condenser, a thermometer, a nitrogen introduction tube, and a stirring rod, 4,4′-dihydroxybiphenyl, dodecanedioic acid, and acetic anhydride were each in a molar ratio of 1.0: 1.1: 2. .1 was charged, and sodium acetate was used as a catalyst to react at 145 ° C. under atmospheric pressure and nitrogen atmosphere to obtain a uniform solution, and then heated to 250 ° C. at 2 ° C./min while acetic acid was distilled off. And stirred at 250 ° C. for 1 hour. Subsequently, while maintaining the temperature, the pressure was reduced to 10 Torr over about 40 minutes, and then the reduced pressure state was maintained. Three hours after the start of pressure reduction, the pressure was returned to normal pressure with nitrogen gas, and the produced polymer was taken out. Various data of the obtained resin are shown in Table 2. Let the obtained resin be (ii).

[Examples 1 to 4]
Resins (i) and (ii) obtained in Production Examples 1 and 2 were dried at 120 ° C. for 4 hours using a hot air dryer, and prepared by mixing so as to have the volume ratio shown in Table 4 did. To this, 0.2 parts by weight of a phenol-based stabilizer (AO-60 manufactured by ADEKA Co., Ltd.) and a phosphorus-based antioxidant (ADEKA STAB PEP-36 manufactured by ADEKA Co., Ltd.) were respectively added.

  This mixture is melt-kneaded using a 15 mm co-rotating fully meshed twin screw extruder KZW15-45MG manufactured by Technobel Co., Ltd. with the barrel temperature set as shown in Table 3, and the thermoplastic resin discharged from the die head part. Was cooled with water to obtain a resin composition. The discharge amount was set to 20 g / min, and the screw rotation speed was set to 150 rpm. The thermoplastic resin in the twin screw extruder sequentially flows from C1 to C6 and is discharged from the die head portion. The obtained pellets of the resin composition were molded using an injection molding machine, and the thermal conductivity in the thickness direction and in the plane direction was measured. The injection molding was performed under the conditions of a cylinder temperature of 220 ° C., a mold temperature of 150 ° C., and an injection speed of 150 mm / sec. Table 4 shows thermal conductivity values.

An aluminum plate heated in advance at 150 ° C. was placed in a mold using an injection molding machine [manufactured by Toyo Machine Metal Co., Ltd., Si-30IV], and the cylinder temperature was 220 ° C. Injection molding was performed under conditions of a mold temperature of 150 ° C. and an injection speed of 150 mm / sec to obtain a metal resin composite shown in FIGS.

[Comparative Examples 1-6]
A resin composition and a metal composite were obtained in the same manner as in Example 1 except that the thermoplastic resin (i), the barrel temperature, and the injection molding conditions were changed.
In the injection molding, an aluminum plate heated in advance at 120 ° C. was placed in a mold, and injection molding was performed under the conditions of a cylinder temperature of 280 ° C., a mold temperature of 120 ° C., and an injection speed of 100 mm / sec. Table 4 shows thermal conductivity values.

Measurement of heat dissipation effect:
As shown in FIG. 4, the test piece for evaluation (metal resin composite) was installed in the center of a room (25 ° C.) made of a transparent plate made of acrylic resin and having a height, width and height of 2 m. . A heating element (10 × 10 × 2 mm, alumina: 36 W / mK, 0.9 mm diameter nichrome wire connection) was bonded to the aluminum plate of the test piece as shown in FIGS. 1 a to 3 b and a voltage of 5 W was applied. , Left for 60 minutes. After confirming that the temperature of the heating element reached equilibrium, the temperature of the heating element was measured. Table 4 shows the temperature of the heating element.

  From Tables 4 and 5, in Examples 1 to 4 and Comparative Examples 1 to 3, when compared at the same blending ratio, the thermoplastic resin composition of the present invention has a higher thermal conductivity in the thickness direction, and heat dissipation. Moreover, when it compares with Examples 1-3 and Comparative Examples 4-6, it can be said that an effect is high, and the one where the heat conductivity of the thickness direction is higher than the heat conductivity of a surface direction, the temperature of a heat generating body is low, and the thickness direction It shows that the resin composition having a higher thermal conductivity of the heat transfer to the metal more. From these, it can be said that the metal resin composite of the present invention exhibits an excellent heat dissipation effect.

  The metal resin composite of the present invention exhibits excellent thermal conductivity and heat dissipation effect. Such a metal-resin composite can be used as a resin material for heat dissipation and heat transfer in various situations such as in the electric / electronic industry and automobile fields, and is industrially useful.

Claims (13)

A metal-resin composite obtained by disposing a metal member inside a mold and forming a resin molded portion on at least a part of the surface of the metal member, the thermoplastic resin forming the resin molded portion The structure of the main chain is general formula (1)

(Wherein X represents a divalent substituent selected from the group of O and CO)
Unit (A) having a biphenyl group represented by 25 to 60 mol%,
General formula (2)
-YR-Y- (2)
(In the formula, R represents a divalent linear substituent which may contain a branch having 2 to 20 main chain atoms. Y represents a divalent substituent selected from the group of O and CO.)
Unit (B) represented by 25 to 60 mol%,
General formula (3)
-Z ¹ -MZ ^2- (3)
(In the formula, Z ¹ and Z ² represent a divalent substituent selected from the group of O, NH, CO, S and NHCO. M represents an aromatic group having a main chain folding effect, a condensed aromatic group, A substituent selected from a heterocyclic group, an alicyclic group, and an alicyclic heterocyclic group is shown.)
Unit (C) represented by 0 to 25 mol% (however, the total of units (A), (B), and (C) is 100 mol%), and the thermal conductivity of the resin alone is 0.4 W / (M * K) The metal resin composite which consists of a thermoplastic resin composition which is more than. The metal resin composite according to claim 1, wherein 60 mol% or more of molecular chain terminals of the thermoplastic resin are carboxyl groups. The metal resin composite according to claim 1, wherein X in the general formula (1) is O and Y in the general formula (2) is CO. The metal resin composite according to any one of claims 1 to 3, wherein a portion corresponding to R of the thermoplastic resin is a linear aliphatic hydrocarbon chain. The metal resin composite according to any one of claims 1 to 4, wherein the number of main chain atoms in a portion corresponding to R of the thermoplastic resin is an even number. 6. The thermoplastic resin according to claim 1, wherein R of the thermoplastic resin is at least one selected from — (CH ₂ ) ₈ —, — (CH ₂ ) ₁₀ —, and — (CH ₂ ) ₁₂ —. Metal resin composite. The metal resin composite according to any one of claims 1 to 6, wherein M of the thermoplastic resin is any one of the structures shown below.

The metal resin composite according to claim 1, wherein the thermoplastic resin has a number average molecular weight of 3000 to 40000. The metal resin composite according to any one of claims 1 to 8, wherein a ratio of lamellar crystals in the thermoplastic resin is 10 Vol% or more.   A metal resin composite comprising an inorganic filler having a thermal conductivity of 1 W / (m · K) or more as a single substance in the thermoplastic resin composition.   The inorganic filler is one or more electrically insulating high heat selected from the group consisting of boron nitride, aluminum nitride, silicon nitride, aluminum oxide, magnesium oxide, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, beryllium oxide and diamond. It is a conductive inorganic compound, The metal resin composite of Claim 10 characterized by the above-mentioned.   The inorganic filler is one or more conductive high thermal conductive inorganic compounds selected from the group consisting of graphite, conductive metal powder, soft magnetic ferrite, carbon fiber, conductive metal fiber, and zinc oxide. The metal resin composite according to claim 11.   It is a structure which has a metal resin composite and a heat generating body in any one of Claims 1-12, Comprising: A thermoplastic resin composition exists between the metal of a heat generating body and a metal resin composite. Characteristic structure.

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