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  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/08—Materials not undergoing a change of physical state when used
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
  • C08L83/06—Polysiloxanes containing silicon bound to oxygen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/06—Preparatory processes
  • C08G77/08—Preparatory processes characterised by the catalysts used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/14—Polysiloxanes containing silicon bound to oxygen-containing groups
  • C08G77/18—Polysiloxanes containing silicon bound to oxygen-containing groups to alkoxy or aryloxy groups
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/20—Oxides; Hydroxides
  • C08K3/22—Oxides; Hydroxides of metals
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
  • C08L83/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/12—Polysiloxanes containing silicon bound to hydrogen
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  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/20—Polysiloxanes containing silicon bound to unsaturated aliphatic groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/20—Oxides; Hydroxides
  • C08K3/22—Oxides; Hydroxides of metals
  • C08K2003/2227—Oxides; Hydroxides of metals of aluminium
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K2201/00—Specific properties of additives
  • C08K2201/001—Conductive additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
  • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2314/00—Polymer mixtures characterised by way of preparation
  • C08L2314/08—Polymer mixtures characterised by way of preparation prepared by late transition metal, i.e. Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru or Os, single site catalyst

Definitions

• the present invention relates to a thermally conductive composition and a thermally conductive member.
• Curable and liquid thermally conductive compositions are widely known. For example, they are filled between a heating element and a heat radiating element, and then hardened to form a cured product, which absorbs the heat generated by the heating element. It is used as a heat conductive member such as a heat dissipation gap filler that transmits heat to a heat dissipation body.
• a heat conductive member such as a heat dissipation gap filler that transmits heat to a heat dissipation body.
• silicone thermally conductive compositions containing an organopolysiloxane and a thermally conductive filler have been widely used as thermally conductive compositions.
• Patent Document 1 an organopolysiloxane having at least two alkenyl groups in one molecule, (B) a hydrolyzable dimethylpolysiloxane with trifunctionality at one end, and (C) a thermally conductive filler. (D) an organohydrogenpolysiloxane having a hydrosilyl group at its terminal, (E) an organohydrogenpolysiloxane having at least two hydrosilyl groups in one molecule, and (F) a platinum catalyst.
• a thermally conductive silicone composition is disclosed.
• Patent Document 1 by adjusting the ratio of hydrosilyl groups and alkenyl groups in component (A), component (D), and component (E) within a predetermined range, the It has been shown that it can suppress the occurrence of pump-out and peeling, and also suppress the increase in thermal resistance.
• the surface temperature of a heat-generating electronic component such as an IC package is about 120° C., and there is no mention of reliability at higher temperatures.
• heat dissipation gap fillers formed from conventional thermally conductive silicone thermally conductive compositions are used for long periods in high-temperature environments of 150°C or higher, their flexibility decreases, making them difficult to use for heating elements and heat dissipation elements. Since peeling occurs, it is difficult to suppress an increase in thermal resistance.
• the present invention has been made in view of the above problems, and even in a usage environment of 150°C or higher, peeling from heating elements and heat radiating elements is less likely to occur, and an increase in thermal resistance is suppressed.
• An object of the present invention is to provide a thermally conductive composition from which a thermally conductive member can be obtained.
• the present inventors have determined that in a thermally conductive composition having specific components (A) to (F), the concentrations of hydrosilyl groups in components (B) and (C) are adjusted within a predetermined range. , or type E hardness after adjusting the Raman intensities p1 and p2 derived from hydrosilyl groups in the Raman spectra to satisfy a predetermined relationship, and standing at 25°C for 24 hours, and further standing at 150°C for 250 hours.
• the inventors have discovered that the above problem can be solved by controlling (E2) below a certain value, and have completed the following invention. That is, the present invention provides the following [1] to [23].
• the Raman intensity p1 at 2160 cm -1 and the Raman intensity p2 at 2130 cm -1 in the Raman spectrum satisfy the relationship of the following formula (1-1), A thermally conductive composition whose Type E hardness E2 satisfies the following formula (2) after being left at 25°C for 24 hours and further left at 150°C for 250 hours.
• E a thermally conductive filler;
• the Raman intensity p1 at 2160 cm-1 and the Raman intensity p2 at 2130 cm-1 satisfy the relationship of formula (1-1) below,
• a first agent which has a Type E hardness E2 that satisfies the following formula (2) after mixing the first agent and the second agent and allowing the mixture to stand at 25° C. for 24 hours and further at 150° C. for 250 hours.
• a second agent which has a Type E hardness E2 that satisfies the following formula (2) after mixing the first agent and the second agent, leaving it at 25° C. for 24 hours, and further leaving it at 150° C. for 250 hours.
• b is the hydrosilyl group concentration of component (B)
• c is the hydrosilyl group concentration of component (C).
• E2 ⁇ 70...(2) [20] A method of mixing the first agent described in [14], [16] or [18] above with the second agent.
• [21] A method of mixing the second agent described in [15], [17] or [19] above into the first agent.
• [22] Use of the first agent according to [14], [16] or [18] above in a two-component thermally conductive composition.
• [23] Use of the second agent according to [15], [17] or [19] above in a two-component thermally conductive composition.
• thermally conductive composition of the present invention even in a usage environment of 150° C. or higher, it is difficult to peel off from a heating element or a heat radiating element, and an increase in thermal resistance is suppressed. Obtainable.
• the thermally conductive composition of the present invention has the following components (A) to (F). Components (A) to (F) will be explained in detail below.
• Component (A) is an organopolysiloxane having two or more alkenyl groups.
• the thermally conductive composition can undergo an addition reaction with the organohydrogenpolysiloxane described below to form a cured product having appropriate hardness.
• the organopolysiloxane having two or more alkenyl groups used as component (A) may be linear or branched, or may be a mixture of linear and branched; It is preferable that there be.
• the alkenyl group in component (A) may be contained either at the end or in the middle of the molecular chain of the polysiloxane structure of component (A), and may be contained at both the end and in the middle, but it should be contained at least at the end. It is preferable to contain it at both ends of the molecular chain formed by the polysiloxane structure, and even more preferably to contain it only at both ends.
• the alkenyl group is not particularly limited, but includes, for example, those having 2 to 8 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, etc.
• the alkenyl group is preferably an alkenyl group directly bonded to a silicon atom.
• the number of alkenyl groups in one molecule in component (A) is not particularly limited as long as it is 2 or more, but is, for example, 2 to 4, preferably 2 to 3, more preferably 2.
• the remaining groups bonded to silicon atoms other than alkenyl groups include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl and dodecyl groups, aryl groups such as phenyl, 2-phenylethyl, Examples include aralkyl groups such as 2-phenylpropyl group, and further specific examples include substituted hydrocarbon groups such as chloromethyl group and 3,3,3-trifluoropropyl group. Among these, methyl group is preferred from the viewpoint of ease of synthesis.
• component (A) preferably does not have a hydrogen atom as a remaining group bonded to a silicon atom, that is, component (A) preferably does not contain a hydrosilyl group.
• the organopolysiloxane of component (A) may be used alone or in combination of two or more.
• component (A) at 25°C is not particularly limited, but is, for example, 80 to 5000 mPa ⁇ s, preferably 150 to 2500 mPa ⁇ s, more preferably 200 to 1500 mPa ⁇ s, and still more preferably 250 to 800 mPa ⁇ s. .
• component (A) may be blended as a mixture with component (C), which will be described later. , preferably 150 to 2500 mPa ⁇ s, more preferably 200 to 1500 mPa ⁇ s, even more preferably 250 to 800 mPa ⁇ s.
• the viscosity of component (A) or a mixture of components (A) and (C) By setting the viscosity of component (A) or a mixture of components (A) and (C) to the above lower limit or higher, the crosslinking density of the cured product can be prevented from becoming too high, and flexibility after curing can be improved. Easier to maintain. Moreover, by setting it below the said upper limit, a thermally conductive composition can be prevented from becoming highly viscous. Furthermore, by setting the viscosity within the above range, it becomes easier to appropriately adjust the reactivity of component (A) or components (A) and (C).
• component (A) is such that the viscosity at 25°C of component (A) blended in the first part is adjusted to the above viscosity range, and The viscosity at 25° C. of the mixture of component (A) and component (C) to be blended may be adjusted to the above viscosity range.
• the content of the component (A) is determined so that the Raman intensity ratio H/Vi, the content ratio H/Vi, the total Vi content, the ratio of the DVi content to the total Vi content, etc., which will be described later, can be adjusted within the desired range.
• it may be selected as appropriate, for example, from 20 to 70% by mass, preferably from 25 to 60% by mass, more preferably from 30 to 50% by mass, based on the total amount of organopolysiloxane contained in the thermally conductive composition. Mass%.
• Component (B) is an organohydrogenpolysiloxane having two hydrosilyl groups.
• the thermally conductive composition undergoes an addition reaction with the (A) component and the (D) component to extend the chain, thereby forming a cured product having appropriate hardness.
• the thermally conductive composition of the present invention has not only the component (C) described below but also the component (B) as an organohydrogenpolysiloxane, so that the crosslinking points are not too dense and have a moderate A cured product with flexibility can be formed.
• Component (B) may be linear or branched, or a mixture of linear and branched, but is preferably linear.
• the hydrosilyl group may be contained either at the end of the molecular chain of the polysiloxane structure or in the middle of the molecular chain, and may be contained at both the end and the middle, but it should be contained at least at the end. More preferably, two hydrosilyl groups are contained at both ends of the molecular chain of the polysiloxane structure.
• the remaining groups bonded to silicon atoms other than the hydrosilyl group include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, hexyl group, and dodecyl group, aryl groups such as phenyl group, Examples include aralkyl groups such as 2-phenylethyl group and 2-phenylpropyl group, and further specific examples include substituted hydrocarbon groups such as chloromethyl group and 3,3,3-trifluoropropyl group. Among these, methyl group is preferred from the viewpoint of ease of synthesis.
• component (B) preferably does not have an alkenyl group as the remaining group bonded to the silicon atom, that is, component (B) preferably does not contain an alkenyl group.
• the organopolysiloxane (B) component may be used alone or in combination of two or more.
• the viscosity of component (B) at 25° C. is not particularly limited, but is, for example, 10 to 2000 mPa ⁇ s, preferably 40 to 1500 mPa ⁇ s, and more preferably 80 to 1200 mPa ⁇ s.
• the viscosity of component (B) is not particularly limited, but is, for example, 10 to 2000 mPa ⁇ s, preferably 40 to 1500 mPa ⁇ s, and more preferably 80 to 1200 mPa ⁇ s.
• the content of component (B) is appropriately selected so that the Raman intensity ratio p2/p1, Raman intensity ratio H/Vi, b/(b+c), content ratio H/Vi, etc., which will be described later, can be adjusted within predetermined ranges.
• the amount may be, for example, 3 to 35% by weight, preferably 5 to 30% by weight, and more preferably 8 to 25% by weight.
• Component (C) is an organohydrogenpolysiloxane having three or more hydrosilyl groups.
• Component (C) undergoes an addition reaction with component (A) and component (D) to cure the thermally conductive composition and form a crosslinked structure in the cured product.
• Component (C) may be linear or branched, or may be a mixture of linear and branched, but is preferably linear.
• the hydrosilyl group may be contained either at the end of the molecular chain of the polysiloxane structure or in the middle of the molecular chain, but it is preferably contained at both the end and the middle.
• the number of hydrosilyl groups in one molecule in component (C) is not particularly limited as long as it is 3 or more, but is, for example, 3 to 25, preferably 8 to 20.
• component (C) the remaining groups bonded to the silicon atom are the same as those listed for component (B), but methyl groups are preferred from the viewpoint of ease of synthesis. Furthermore, of the remaining groups bonded to the silicon atom, 80 mol% or more is preferably a methyl group, more preferably 90 mol% or more is a methyl group, and 100 mol% is preferably a methyl group. More preferred. Note that component (C) preferably does not have an alkenyl group as the remaining group bonded to the silicon atom, that is, component (C) preferably does not contain an alkenyl group.
• the organopolysiloxane of component (C) may be used alone or in combination of two or more.
• the content of component (C) is appropriately selected so that the Raman intensity ratio p2/p1, Raman intensity ratio H/Vi, b/(b+c), content ratio H/Vi, etc., which will be described later, can be adjusted within predetermined ranges.
• the amount may be, for example, 0.2 to 8% by weight, preferably 0.4 to 5% by weight, and more preferably 0.7 to 3% by weight.
• Component (D) is an organopolysiloxane having one alkenyl group or methacryloyl group.
• the thermally conductive composition prevents the crosslinking points from becoming too dense and maintains good flexibility of the cured product even when used in an environment of 150°C or higher. and improve reliability. Therefore, even if the cured product of the thermally conductive composition is used as a heat dissipation gap filler in an environment of 150°C or higher, peeling from the heating element or heat dissipation element is suppressed, and the thermal resistance increases. can be suppressed.
• component (D) undergoes an addition reaction with component (B) or (C) during curing, bleeding out after curing can be prevented.
• the organopolysiloxane used as component (D) may be linear or branched, or may be a mixture of linear and branched, but is preferably linear.
• the alkenyl group or methacryloyl group may be contained at the end of the molecular chain of the polysiloxane structure or in the middle of the molecular chain, but it is preferably contained at the end, and it is contained at one end of the molecular chain of the polysiloxane structure. It is more preferable.
• Component (D) preferably contains either one alkenyl group or methacryloyl group in its molecule, and preferably contains one methacryloyl group from the viewpoint of obtaining a cured product with excellent heat resistance.
• the alkenyl group in component (D) is not particularly limited, but includes, for example, those having 2 to 8 carbon atoms, and specific examples thereof are as described for component (A), and from the viewpoint of ease of synthesis, etc.
• a vinyl group is preferred.
• the alkenyl group is preferably an alkenyl group directly bonded to a silicon atom.
• the methacryloyl group may be a methacryloyl group directly bonded to a silicon atom, but it may also be any divalent group (for example, a divalent saturated aliphatic hydrocarbon group, a group represented by -XO-) However, X may be bonded to a silicon atom via a divalent saturated aliphatic hydrocarbon group) or an oxygen atom.
• component (D) the remaining groups bonded to the silicon atom are the same as those listed for component (A), but methyl groups are preferred from the viewpoint of ease of synthesis. Furthermore, of the remaining groups bonded to the silicon atom, 80 mol% or more is preferably a methyl group, more preferably 90 mol% or more is a methyl group, and 100 mol% is preferably a methyl group. More preferred. Note that component (D) preferably does not have a hydrogen atom as a remaining group bonded to a silicon atom, that is, component (D) preferably does not contain a hydrosilyl group.
• the organopolysiloxane of component (D) may be used alone or in combination of two or more.
• the viscosity of component (D) at 25° C. is not particularly limited, but is, for example, 10 to 2000 mPa ⁇ s, preferably 50 to 1000 mPa ⁇ s, more preferably 80 to 600 mPa ⁇ s.
• the viscosity of component (D) is not particularly limited, but is, for example, 10 to 2000 mPa ⁇ s, preferably 50 to 1000 mPa ⁇ s, more preferably 80 to 600 mPa ⁇ s.
• the content of component (D) is adjusted so that the Raman intensity ratio H/Vi, content ratio H/Vi, total Vi content, ratio of DVi content to total Vi content, etc., which will be described later, can be adjusted within desired ranges.
• it may be selected as appropriate, for example, from 1 to 30% by mass, preferably from 5 to 25% by mass, more preferably from 8 to 25% by mass, based on the total amount of organopolysiloxane contained in the thermally conductive composition. It is 20% by mass.
• Component (E) is a thermally conductive filler.
• the thermally conductive composition of the present invention contains a thermally conductive filler, thereby improving the thermal conductivity of the thermally conductive composition and the cured product (thermally conductive member) obtained by curing the thermally conductive composition. Improves sex.
• the thermally conductive filler include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides other than metals, nitrides, and carbides.
• the shape of the thermally conductive filler may be spherical, irregularly shaped powder, or the like.
• metals include aluminum, copper, nickel, and the like.
• metal oxides include aluminum oxide typified by alumina, magnesium oxide, zinc oxide, and the like.
• metal nitrides include aluminum nitride.
• metal hydroxides include aluminum hydroxide.
• carbon materials include spherical graphite and diamond.
• oxides, nitrides, and carbides other than metals include quartz, boron nitride, and silicon carbide.
• metal oxides, metal nitrides, and carbon materials are preferable as the thermally conductive filler from the viewpoint of improving thermal conductivity, and among these, metal oxides are more preferable.
• aluminum oxide, aluminum nitride, and diamond are preferable, and aluminum oxide is more preferable.
• thermally conductive fillers may be used alone or in combination of two or more.
• aluminum oxide in combination with at least one of diamond or aluminum nitride.
• aluminum oxide and aluminum hydroxide together.
• the average particle size of the thermally conductive filler is preferably 0.1 to 200 ⁇ m, more preferably 0.3 to 100 ⁇ m, and even more preferably 0.5 to 70 ⁇ m.
• the thermally conductive filler may be a small-particle thermally conductive filler with an average particle size of 0.1 ⁇ m or more and 5 ⁇ m or less, and a large-particle thermally conductive filler with an average particle size of more than 5 ⁇ m and 200 ⁇ m or less. preferable.
• the filling rate can be increased.
• the average particle size means the particle size (D50) at a volume integration of 50% in the particle size distribution of the thermally conductive filler determined by a laser diffraction/scattering method.
• the content of the thermally conductive filler in the thermally conductive composition is preferably 150 to 4000 parts by mass, more preferably 500 to 3500 parts by mass based on 100 parts by mass of organopolysiloxane contained in the thermally conductive composition. parts, more preferably 1000 to 3200 parts by weight, even more preferably 1500 to 3000 parts by weight. Further, the volume-based content of the thermally conductive filler is preferably 50 to 95% by volume, more preferably 70 to 93% by volume, and even more preferably It is 75 to 92% by volume, more preferably 80 to 90% by volume.
• the thermally conductive filler By setting the content of the thermally conductive filler to the above lower limit or more, a certain level of thermal conductivity can be imparted to the thermally conductive composition and its cured product. By setting the content of the thermally conductive filler to the above upper limit or less, the thermally conductive filler can be appropriately dispersed. Moreover, it is also possible to prevent the viscosity of the thermally conductive composition from becoming higher than necessary.
• Component (F) is a platinum group curing catalyst.
• the thermally conductive composition of the present invention contains a platinum group curing catalyst to promote the addition reaction between the organopolysiloxane containing an alkenyl group and the organohydrogenpolysiloxane, thereby forming a thermally conductive composition. can be properly cured.
• the platinum group curing catalyst include, but are not particularly limited to, chloroplatinic acid, complex compounds of chloroplatinic acid and olefins, vinyl siloxane, or acetylene compounds, and the like.
• the content of the platinum group curing catalyst in the thermally conductive composition is not particularly limited as long as it is contained in an amount that can promote the addition reaction, but it is not particularly limited as long as it is contained in an amount that can promote the addition reaction. , for example, 0.001 to 1 part by weight, preferably 0.005 to 0.5 part by weight.
• the thermally conductive composition of the present invention further contains an organopolysiloxane having no addition reactive group as component (G).
• component (G) the thermally conductive composition of the present invention prevents more than a certain amount of the component from being incorporated into the crosslinked structure in the cured product, making it easier to improve flexibility. Moreover, it becomes easier to reduce the viscosity of the thermally conductive composition, and it becomes easier to improve handleability.
• the addition reaction group means a functional group that reacts by an addition reaction, and typical examples thereof include an alkenyl group, a methacryloyl group, an acryloyl group, a hydrosilyl group, and the like.
• component (G) the cured product can be made flexible.
• Component (G) includes (G-1) silicone oil and (G-2) organopolysiloxane having at least one alkoxy group.
• Component (G) may contain either one of component (G-1) or component (G-2), but preferably contains at least component (G-2). By containing component (G-2), the viscosity of the thermally conductive composition can be further reduced. When the thermally conductive composition contains component (G-2), it may further contain component (G-1).
• Silicone oils include straight silicone oils such as dimethyl silicone oil and phenylmethyl silicone oil, as well as non-reactive main chains with a polysiloxane structure, side chains bonded to the main chain, or terminals of the main chain. Examples include non-reactive modified silicone oil into which a reactive organic group has been introduced. A non-reactive organic group is an organic group that does not have an addition reactive group. Examples of non-reactive modified silicone oils include polyether-modified silicone oil, aralkyl-modified silicone oil, fluoroalkyl-modified silicone oil, long-chain alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, higher fatty acid amide-modified silicone oil, and phenyl-modified silicone oil. Among the above, straight silicone oil is preferable as the silicone oil, and dimethyl silicone oil is more preferable among the straight silicone oils. (G-1) Silicone oil may be used alone or in combination of two or more.
• Component (G-2) may be linear or branched, or a mixture of linear and branched, but is preferably linear.
• any organopolysiloxane having at least one alkoxy group may be used, but an organopolysiloxane having at least one alkoxy group at the molecular chain end of a polysiloxane structure is preferable, and one terminal More preferred are organopolysiloxanes that only have at least one alkoxy group.
• Component has an alkoxy group, especially an alkoxy group at the end, so that it easily reacts or interacts with functional groups present on the surface of the thermally conductive filler, and has a polysiloxane structure. It is presumed that this combination reduces the friction of the filler and makes it easier to lower the viscosity of the thermally conductive composition.
• component (G-2) preferably has a structure represented by the following formula (X).
• R 1 , R 2 , R 4 , and R 5 are each independently a saturated hydrocarbon group, R 3 is an oxygen atom or a divalent hydrocarbon group, and n is an integer of 15 to 315. and m is an integer from 0 to 2)
• R 1 , R 2 , R 4 and R 5 are each independently a saturated hydrocarbon group.
• the saturated hydrocarbon group include alkyl groups such as a linear alkyl group, a branched alkyl group, and a cyclic alkyl group, an aryl group, an aralkyl group, and a halogenated alkyl group.
• linear alkyl groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, Examples include pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, and the like.
• Examples of the branched alkyl group include isopropyl group, tert-butyl group, isobutyl group, 2-methylundecyl group, and 1-hexylheptyl group.
• Examples of the cyclic alkyl group include a cyclopentyl group, a cyclohexyl group, a cyclododecyl group, and the like.
• Examples of the aryl group include phenyl group, tolyl group, xylyl group, and the like.
• Examples of the aralkyl group include a benzyl group, a phenethyl group, and a 2-(2,4,6-trimethylphenyl)propyl group.
• Examples of the halogenated alkyl group include 3,3,3-trifluoropropyl group and 3-chloropropyl group.
• R 1 to R 5 , m, and n in formula (X) are preferably as follows from the viewpoint of enhancing the viscosity reduction effect.
• R 1 in formula (X) is preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 2 to 6 carbon atoms, and particularly preferably a butyl group.
• R 2 , R 4 , and R 5 in formula (X) are each independently preferably an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably methyl. It is the basis.
• R 3 in formula (X) is an oxygen atom or a divalent hydrocarbon group, and preferably a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include a methylene group, an ethylene group, a propylene group, a butylene group, a methylethylene group, and among them, an ethylene group is preferred.
• n in formula (X) is an integer of 15 to 315, preferably an integer of 18 to 280, more preferably an integer of 20 to 220.
• m in formula (X) is an integer of 0 to 2, preferably 0 or 1, and more preferably 0. Therefore, component (G-2) is preferably an organopolysiloxane having a trialkoxysilyl group at one end. Component (G-2) may be used alone or in combination of two or more.
• the viscosity of component (G) at 25° C. is not particularly limited, but is, for example, 1 to 800 mPa ⁇ s, preferably 5 to 250 mPa ⁇ s, and more preferably 10 to 150 mPa ⁇ s.
• the content of component (G) in the thermally conductive composition is, for example, 3 to 63% by mass based on the total amount of organopolysiloxane contained in the thermally conductive composition.
• the content of component (G) component is preferably 5 to 50% by mass, more preferably 10 to 40% by mass, and even more preferably 15 to 35% by mass.
• component (G) preferably contains component (G-2).
• the content of component (G-2) in the thermally conductive composition is preferably 2 to 40% by mass, and 4 to 30% by mass, based on the total amount of organopolysiloxane contained in the thermally conductive composition. More preferably, 8 to 20% by mass is even more preferred.
• the thermally conductive composition contains a certain amount or more of the component (G-2) among the components (G), the viscosity of the thermally conductive composition can be further reduced.
• the total content of components (A) to (D) and (G) is preferably 2 to 40% by mass based on the total amount of the thermally conductive composition.
• the total content of components (A) to (D) and (G) is more preferably 3 to 20% by mass, and even more preferably 3.5 to 15% by mass, based on the total amount of the thermally conductive composition. Even more preferably, it is 4 to 10% by mass.
• the organopolysiloxane in the thermally conductive composition of the present invention may be composed of components (A) to (D) or components (A) to (D) and component (G), but this does not impair the effects of the present invention.
• the composition may contain organopolysiloxanes other than components (A) to (D) and component (G) within a certain range.
• the content of organopolysiloxanes other than components (A) to (D) and component (G) is, for example, 30% by mass or less, preferably 20% by mass or less, based on the total amount of organopolysiloxane contained in the thermally conductive composition. % or less, more preferably 10% by weight or less, still more preferably 5% by weight or less, and most preferably 0% by weight.
• additives can be contained in the thermally conductive composition of the present invention.
• additives include reaction control agents, dispersants, flame retardants, plasticizers, antioxidants, and colorants.
• each additive may be contained in either the first part or the second part, but it may be contained in both. The additive may be used by appropriately selecting one or more of these.
• the Raman intensity p1 at 2160 cm -1 and the Raman intensity p2 at 2130 cm -1 in the Raman spectrum satisfy the following equation (1-1).
• the Raman intensity p1 at 2160 cm ⁇ 1 in the Raman spectrum is the Raman intensity at the peak wavelength derived from the hydrosilyl group contained in the middle of the molecular chain of the polysiloxane structure.
• the Raman intensity p2 at 2130 cm ⁇ 1 in the Raman spectrum is the Raman intensity at the peak wavelength derived from the hydrosilyl group contained at the end of the molecular chain of the polysiloxane structure. Therefore, p2/p1 can be said to be an index indicating the amount of terminal hydrosilyl groups relative to the hydrosilyl groups contained in the middle of the molecular chain.
• p2/p1 is preferably 3.10 or more, more preferably 3.20 or more, and even more preferably 3.30 or more. Further, p2/p1 is preferably less than 5.5. By setting p2/p1 to less than 5.5, it becomes easier to introduce a three-dimensional crosslinked structure into the cured product with an appropriate crosslinking density. Therefore, it becomes easier to maintain the hardness at a constant value even when heated at high temperatures for a long period of time, and it becomes easier to improve long-term heat resistance. From the above viewpoint, p2/p1 is more preferably less than 4.5, even more preferably 4.2 or less, and even more preferably 4.0 or less.
• the values of the Raman intensity ratio p2/p1 above are the content of component (B), the concentration of the hydrosilyl group at the end of the molecular chain of component (B), the content of component (C), and the middle of the molecular chain of component (C). It can be adjusted by adjusting the concentration of the hydrosilyl group. Specifically, increasing the content of component (B), increasing the concentration of the hydrosilyl group at the end of the molecular chain contained in component (B), decreasing the content of component (C), The value of p2/p1 can be increased by either or a combination of C) lowering the concentration of hydrosilyl groups in the middle of the molecular chain contained in the component. Furthermore, the value of p2/p1 can be reduced by adjusting the opposite.
• the ratio of the intensity of the peak derived from the hydrosilyl group to the intensity of the peak derived from the alkenyl group and methacryloyl group is, for example, 7.00 to 13.50. , preferably from 7.00 to 12.00, more preferably from 7.50 to 11.00.
• the value of the above Raman intensity ratio H/Vi is based on the content of component (A), the content of component (B), the content of component (C), the content of component (D), the alkenyl group of each component, It can be adjusted by adjusting the concentration of methacryloyl group, hydrosilyl group, etc. Specifically, reducing the content of component (A), reducing the content of component (D), lowering the concentration of alkenyl groups in component (A), and reducing the alkenyl group in component (D).
• H/Vi can be increased by increasing the concentration of hydrosilyl groups contained in component (C) or by a combination thereof. Furthermore, the value of H/Vi can be reduced by adjusting the opposite.
• the organopolysiloxane and the thermally conductive filler in the thermally conductive composition it is preferable to separate at least the organopolysiloxane and the thermally conductive filler in the thermally conductive composition, and perform Raman measurement on the organopolysiloxane.
• components other than organopolysiloxane may be mixed with the organopolysiloxane as long as they do not affect the measurement. Therefore, it is usually preferable to separate the liquid component and solid component using a centrifuge or the like, and then measure the Raman spectrum of the liquid component.
• p1 may be calculated from the Raman spectrum of the second agent. This is because the organohydrogenpolysiloxane is not contained in the first part but only in the second part.
• the measurement conditions for Raman measurement are as described in Examples.
• the alkenyl group is typically a vinyl group
• the Raman intensity ratio H/Vi described above is typically an index of the hydrosilyl group/(vinyl group + methacryloyl group) ratio, as shown in the examples below. It can be obtained by calculating.
• "combining the first agent and the second agent” or “combining the second agent and the first agent” means combining the first agent and the second agent as described above. It means to calculate using separately measured values.
• component (B) and component (C) are contained so as to satisfy the relationship of formula (1-2) below.
• b is the concentration of hydrosilyl groups contained in component (B)
• c is the concentration of hydrosilyl groups contained in component (C).
• concentration of hydrosilyl groups here refers to the concentration of hydrosilyl groups in the thermally conductive composition.
• the organohydrogenpolysiloxane is not contained in the first part, but only in the second part.
• component (B) and component (C) are preferably contained in the second agent so as to satisfy the relationship of formula (1-2).
• the concentration ratio of the hydrosilyl groups can be adjusted by adjusting the content of component (B), the concentration of hydrosilyl groups in component (B), the content of component (C), and the concentration of hydrosilyl groups in component (C). can do. Specifically, increasing the content of component (B), increasing the concentration of hydrosilyl groups contained in component (B), decreasing the content of component (C), and increasing the content of component (C).
• the concentration ratio of hydrosilyl groups can be increased by either or a combination of lowering the concentration of hydrosilyl groups contained. Moreover, the concentration ratio of hydrosilyl groups can be reduced by adjusting the opposite.
• the crosslinking points tend to become sparse, making it easier to maintain good flexibility of the cured product in an environment of 150° C. or higher. Therefore, when the cured product of the thermally conductive composition is used as a heat dissipation gap filler in an environment of 150°C or higher, peeling from the heating element or heat dissipation element is less likely to occur, and the problem of increased thermal resistance is less likely to occur. Improved reliability. Furthermore, due to the increased flexibility, for example, when made thick, it can exhibit cushioning properties and can be suitably used in environments where vibrations occur.
• b/(b+c) is preferably 0.48 or more, more preferably 0.50 or more, and even more preferably 0.52 or more. It is preferable that b/(b+c) is less than 0.85. By setting b/(b+c) to less than 0.85, it becomes easier to introduce a crosslinked structure into the cured product with an appropriate crosslinking density. Therefore, it becomes easier to maintain the hardness at a constant value even when heated at high temperatures for a long period of time, and it becomes easier to improve long-term heat resistance.
• b/(b+c) is more preferably 0.75 or less, even more preferably 0.70 or less, and even more preferably 0.63 or less.
• concentration of the hydrosilyl group of the component (B) and the component (C) can be a value calculated from the integral ratio of the 1H-NMR spectrum measured using an NMR measuring device.
• the total content of alkenyl groups and methacryloyl groups (hereinafter also referred to as "total Vi content”) in the thermally conductive composition is preferably 5.0 ⁇ mol/g or less.
• the total Vi content is more preferably 4.8 ⁇ mol/g or less, still more preferably 4.5 ⁇ mol/g or less, even more preferably 4.2 ⁇ mol/g or less.
• the total Vi content is preferably 0.5 ⁇ mol/g or more, more preferably 1.0 ⁇ mol/g or more, and 2.0 ⁇ mol/g from the viewpoint of imparting constant curability and appropriate crosslinking density to the thermally conductive composition. It is more preferably at least 3.0 ⁇ mol/g, even more preferably at least 3.0 ⁇ mol/g.
• the content of the alkenyl group can be a value calculated from the integral ratio of a 1H-NMR spectrum measured using an NMR measuring device.
• the total content of alkenyl groups and methacryloyl groups (hereinafter also referred to as "DVi content") contained in component (D) (i.e., organopolysiloxane having one alkenyl group or methacryloyl group) is the above-mentioned
• the total Vi content is preferably 0.05 or more.
• the DVi content is more preferably 0.10 or more, even more preferably 0.15 or more, and even more preferably 0.19 or more with respect to the total Vi content.
• the DVi content is preferably 0.40 or less, more preferably 0.35 or less, and 0.40 or less, more preferably 0.35 or less, based on the total Vi content. It is more preferably 30 or less, and even more preferably 0.28 or less.
• the total content of alkenyl groups and methacryloyl groups is the content of component (A), the content of component (D), the concentration of alkenyl groups in component (A), and the alkenyl and methacryloyl groups in component (D). It can be adjusted by adjusting the concentration of.
• the total content of alkenyl groups and methacryloyl groups can be increased by either or a combination of: and increasing the total concentration of methacryloyl groups.
• the total content of alkenyl groups and methacryloyl groups can be reduced by adjusting the opposite.
• the total content of alkenyl groups and methacryloyl groups contained in component (D) can be adjusted by adjusting the content of component (D) and the concentration of alkenyl groups and methacryloyl groups in component (D). Can be done.
• the alkenyl contained in component (D) can be reduced by increasing the content of component (D) or increasing the total concentration of alkenyl groups and methacryloyl groups in component (D), or by a combination thereof.
• the total content of groups and methacryloyl groups can be increased.
• the total content of alkenyl groups and methacryloyl groups contained in component (D) can be reduced by the reverse adjustment.
• the concentration ratio of hydrosilyl groups (b/(b+c)), total Vi content, DVi content, and content ratio H/Vi explained above are based on the amount of functional groups of each component to be blended and the content ratio of each component. It can be calculated from the content. Note that the method for adjusting the value of the content ratio H/Vi is the same as the method for adjusting the Raman intensity ratio H/Vi.
• the thermally conductive composition of the present invention has a Type E hardness (E2) that satisfies the following formula (2) after being left at 25°C for 24 hours and further left at 150°C for 250 hours. E2 ⁇ 70...(2)
• E2 ⁇ 70...(2) the first part and the second part may be mixed and then left at 25° C. for 24 hours. The same applies to other hardness measurements.
• Type E hardness (E2) above is 70 or higher, it is easy to maintain the flexibility of the cured product in an environment of 150°C or higher, but it is too hard and it is difficult to alleviate stress such as vibration, so it is difficult to use a heating element. Peeling from the heat sink is likely to occur. Therefore, when a cured product of a thermally conductive composition is used as a heat dissipation gap filler (thermally conductive member) in an environment of 150°C or higher, it may peel off from the heating element or heat dissipation element, resulting in an increase in thermal resistance. occurs, reducing reliability.
• the type E hardness (E2) is preferably 69 or less, more preferably 67 or less, and even more preferably 64 or less. It should be noted that the higher the flexibility, the easier it is to exhibit cushioning properties, and it can be suitably used in an environment where vibrations occur. Further, the type E hardness (E2) is not particularly limited, but is, for example, 30 or more, preferably 40 or more, and more preferably 50 or more. By setting the Type E hardness (E2) above a certain value, it is possible to easily maintain the flexibility of the cured product in an environment of 150°C or higher, and for example, to sufficiently support the weight of a member installed on top of the cured product.
• the above type E hardness (E2) can be obtained, for example, by adjusting the concentration of each component, the concentration of alkenyl groups, methacryloyl groups, and hydrosilyl groups of each component, the Raman intensity ratio H/Vi, and the content ratio H/Vi. Can be adjusted. Specifically, increasing the content of component (A), increasing the content of component (C), increasing the concentration of alkenyl groups in component (A), and increasing the content of hydrosilyl group in component (C). E2 can be increased by either or a combination of increasing the concentration of , bringing the Raman intensity ratio H/Vi or the content ratio H/Vi into a more preferable range.
• component (B) increasing the content of component (B), increasing the content of component (D), adding a large amount of component (G) as necessary, alkenyl groups, methacryloyl groups, hydrosilyl groups of each component.
• E2 can be lowered by lowering the concentration of the group and adjusting the Raman intensity ratio H/Vi and the content ratio H/Vi out of the more preferable range.
• E1 type E hardness (E1) of the thermally conductive composition after being left at 25° C. for 24 hours and the above E2 satisfies the following formula (3). 1.4 ⁇ E2/E1 ⁇ 3.5 (3)
• E2/E1 is 1.4 or more, it can have a predetermined heat resistance while being flexible. Further, when E2/E1 is 3.5 or less, the change in hardness after curing will not be too large, allowing stable fixation.
• E2/E1 is more preferably 1.8 or more, and more preferably 3.0 or less.
• the type E hardness (E1) of the thermally conductive composition after being left at 25° C. for 24 hours is preferably 10 or more, more preferably 15 or more, and even more preferably 20 or more. .
• a cured product having a certain hardness can be obtained simply by leaving it at room temperature. Therefore, for example, after being cured at room temperature, the weight of the member placed on top of the cured product can be sufficiently supported, and compression in the thickness direction during use can be prevented.
• the type E hardness (E1) of the thermally conductive composition is preferably 50 or less, more preferably 46 or less, and even more preferably 40 or less.
• the type E hardness (E1) By setting the type E hardness (E1) to be less than or equal to the above upper limit, the flexibility of the cured product of the thermally conductive composition can be improved.
• the Raman intensity ratio p2/p1 or the Raman intensity ratio H/Vi is adjusted to a predetermined range, and the curing reaction is It is advisable to add component (F) in a predetermined amount so as not to delay the process too much.
• the hardness change expressed by the value of E3-E2 is the same as when heated at 150°C for a long period of time. Represents hardness change.
• the lower the value of E3-E2 the less the change in performance even when used for a long period of time at a temperature of 150° C. or higher, which means that the long-term heat resistance is better.
• the hardness change represented by the value of E3-E2 is preferably 6 or less, more preferably 4 or less, and preferably 2 or less. Note that the hardness change represented by the value of E3-E2 is not particularly limited, but is usually 0 or more.
• the thermally conductive composition of the present invention may be of a one-component type or a two-component type consisting of a combination of a first agent and a second agent, but from the viewpoint of storage stability, a two-component type is preferable.
• a thermally conductive composition is obtained by mixing a first part and a second part at the time of use.
• the mass ratio of the first part to the second part (second part/first part) is preferably 1 or a value close to 1, and is 0.8 to 1. 2 is preferable, 0.9 to 1.1 is more preferable, and 0.95 to 1.05 is more preferable.
• the thermally conductive composition can be easily prepared.
• the method of mixing the first part and the second part to obtain the thermally conductive composition is not limited, but for example, a static mixer, a mixer with stirring blades, a vibration stirrer, etc. or an autorotation-revolution mixer.
• the first part contains an organopolysiloxane having an alkenyl group (alkenyl group-containing organopolysiloxane) and (F) a platinum group curing catalyst; Contains no siloxane.
• the second agent contains organohydrogenpolysiloxane, but does not contain (F) a platinum group curing catalyst.
• at least one of the first agent and the second agent contains (E) a thermally conductive filler.
• both the first part and the second part contain (E) a thermally conductive filler.
• the first agent contains at least one of component (A) and component (D) and component (F), but does not contain component (B) and component (C).
• the second agent contains the (B) component and the (C) component, but does not contain the (F) component.
• either the first agent or the second agent contains component (E).
• the first agent contains at least one of the (A) component and (D) component, the (E) component, and the (F) component, but does not contain the (B) component and the (C) component.
• the second agent contains component (B), component (C), and component (E), but preferably does not contain component (F).
• the first part having the above structure contains (F) a platinum group curing catalyst that promotes the addition reaction, but does not contain organohydrogenpolysiloxane, so the addition reaction proceeds before mixing with the second part. This can be prevented.
• the second part contains organohydrogenpolysiloxane, but does not contain (F) a platinum group curing catalyst that promotes the addition reaction, so it prevents the addition reaction from proceeding before being mixed with the first part. be able to.
• All of the alkenyl group-containing organopolysiloxane constituting the thermally conductive composition may be contained in the first part, but some of it may be contained in the first part and the rest in the second part. is preferred. More specifically, all of the components (A) and (D) in the thermally conductive composition may be contained in the first component, but some of the components (A) and (D) may be contained in the first component. It is preferable that the remaining components (A) and (D) be contained in the second agent.
• the second agent also contains an organohydrogenpolysiloxane, it does not contain (F) a platinum group curing catalyst, so even if it contains an alkenyl group-containing organopolysiloxane, it will not undergo an addition reaction during storage. It can be virtually prevented from progressing.
• the second agent may contain a reaction control agent to prevent the reaction from proceeding in the second agent.
• alkenyl group-containing organopolysiloxane when contained in the second part, it may be blended in the second part as a mixture with the organohydrogenpolysiloxane, for example, component (A) is the component (C). It may be blended into the second agent as a mixture with other components.
• the thermally conductive filler may be contained in either the first part or the second part to form the thermally conductive composition, but as described above, the thermally conductive filler may be contained in either the first part or the second part. It is preferable that it is contained in both, and it is more preferable that it is contained approximately equally. Specifically, the ratio (mass ratio) of the content of the thermally conductive filler (E) in the second agent to the content of the thermally conductive filler (E) in the first agent is 0.67 to 1.
• the thermally conductive composition preferably contains component (G), and component (G) is preferably contained in at least one of the first part and the second part. However, component (G) is preferably contained in at least the first part, and more preferably contained in both the first part and the second part.
• component (G) is contained in both the first and second agents, the viscosity of the first and second agents can be adjusted by the component (G), and the viscosity of both the first and second agents can be adjusted to a relatively low level. It is also possible to change the viscosity.
• component (G) contains component (G-2), it is more effective and preferable to include component (G-2) in both the first agent and the second agent.
• the viscosity VB at 25°C of the binder resin contained in the thermally conductive composition is not particularly limited, but is preferably 50 to 800 mPa ⁇ s, more preferably 80 to 600 mPa ⁇ s, and still more preferably 100 to 400 mPa ⁇ s. be.
• the viscosity VB of the binder resin is the viscosity of the organopolysiloxane contained in the thermally conductive composition, and is usually used for components (A) to (D), or components (A) to (D) and (G). ), but if an organopolysiloxane other than these components is contained, it is the viscosity of the mixture that also includes that organopolysiloxane.
• the viscosities VB1 and VB2 of the binder resins of the first and second agents which will be described later, are also the viscosities of the organopolysiloxanes contained in the first and second agents, respectively.
• the viscosity VB1, VB2 at 25°C of the binder resin contained in the first part and the second part is preferably 50 to 800 mPa ⁇ s, more preferably 80 to 600 mPa. ⁇ s, more preferably 100 to 400 mPa ⁇ s.
• the viscosity VB1, VB2 of the binder resin in the first part and the second part is the viscosity of the organopolysiloxane obtained by mixing the organopolysiloxanes contained in the first part and the second part, respectively. It is good to measure.
• the viscosity VB of the binder resin in the thermally conductive composition can be measured in the same way, but in the case of a two-component thermally conductive composition, the viscosity VB1 and VB2 of the binder resin in the first part and the second part, respectively. It is also possible to roughly estimate the viscosity VB from
• the viscosity V1 and V2 of the first and second agents at a temperature of 25° C. and a shear rate of 3.16 (1/s) are respectively 10 to 1000 Pa ⁇ s. It is preferably 50 to 700 Pa ⁇ s, more preferably 200 to 450 Pa ⁇ s.
• the first agent and the second agent have the above-mentioned viscosities, handling properties are easily improved.
• the viscosity V of the thermally conductive composition of the present invention under the conditions of a temperature of 25° C. and a shear rate of 3.16 (1/s) is preferably 10 to 1000 Pa ⁇ s or less, and 50 to 700 Pa ⁇ s. It is more preferably below, and even more preferably 200 to 450 Pa ⁇ s. Since the thermally conductive composition has the above-mentioned viscosity, it has a predetermined fluidity before curing, and can be applied to narrow gaps and complicated shapes. When the thermally conductive composition is a two-part type, the viscosity V can be determined by mixing the first part and the second part and immediately measuring it. It is also possible to roughly estimate the viscosity value from the viscosities V1 and V2.
• ) described above is preferably small from the viewpoint of making it easier to mix the thermally conductive composition uniformly.
• ) between the first agent and the second agent may be, for example, 130 Pa ⁇ s or less, preferably 100 Pa ⁇ s or less, and 30 Pa ⁇ s or less. It is more preferable.
• ) between the first agent and the second agent may be 0 Pa ⁇ s or more.
• the thermally conductive composition of the present invention is preferably used as a thermally conductive member such as a heat dissipation gap filler.
• the thermally conductive member is a cured product obtained by curing a thermally conductive composition.
• Thermal conductive members are used inside electronic devices and the like. Specifically, the thermally conductive member is interposed between the heat generating element and the heat radiating element, conducts heat generated by the heat generating element to the heat radiating element, and radiates the heat from the heat radiating element.
• the heating element include various electronic components such as a CPU, a power amplifier, and a power supply used inside an electronic device.
• the heat sink examples include a heat sink, a heat pump, and a metal casing of an electronic device.
• the thermally conductive member may be used, for example, in electrical components, and in the electrical components, the heating element may be disposed in the engine room or near the motor. Suitable for use in electrical components exposed to the environment. It is also suitable for heat dissipation from a heating element that generates heat of 150° C. or higher.
• the thermally conductive member may be formed by, for example, filling a gap between a heating element and a heat radiating element with a thermally conductive composition and curing the composition. Curing may be carried out by heating, but it is preferably carried out at around room temperature (for example, about 0 to 40°C, preferably about 15 to 35°C). By curing at around room temperature, the thermally conductive member can be placed inside an electronic device without adding thermal history to the electronic component.
• the thermally conductive composition is a two-component type, it is preferable to mix the first part and the second part, and then fill the gap between the heating element and the heat radiating element, and then harden the composition.
• the shape of the thermally conductive member is not particularly limited, and may be sheet-like or may be used in other shapes.
• the thickness of the thermally conductive member is not particularly limited, and can be used, for example, from 0.3 to 5 mm, preferably from 0.5 to 4 mm. In the present invention, since the thermally conductive member has flexibility, if its thickness is increased (for example, 0.5 mm or more), it can exhibit cushioning properties and can be suitably used in an environment where vibrations occur.
• the Raman intensity ratio p2/p1 was estimated from the Raman intensity p2 at a wave number of 2130 cm ⁇ 1 and the Raman intensity p1 at a wave number of 2160 cm ⁇ 1 for the Raman spectroscopic spectrum obtained from the second agent containing a hydrosilyl group.
• the Raman intensity ratio H/Vi (ratio of the intensity of the peak derived from the hydrosilyl group to the intensity of the peak derived from the alkenyl group and methacryloyl group) was calculated as follows. That is, regarding the Raman spectrum of the first agent and the Raman spectrum of the second agent, first, the area C of the Si-O-Si peak appearing at a wave number of 490 cm -1 , the area D of the vinyl group peak appearing at a wave number of 1600 cm -1 , and the wave number The area E of the methacryloyl group peak appearing at 1640 cm -1 and the area F of the hydrosilyl group peak appearing at wave numbers 2130 to 2160 cm -1 were calculated.
• Viscosity of each organopolysiloxane and viscosity of binder resin The viscosity at 25°C of each organopolysiloxane and the viscosities VB1 and VB2 of the binder resins contained in the first and second parts were measured as follows. Using a rheometer "MCR-302e" manufactured by Anton Paar, the temperature of the sample was adjusted to 25°C with a Peltier plate, and a shear rate of 10 to 100 (1/sec) was adjusted using a cone plate with a diameter of 50 mm and an angle of 1°. ) The viscosity was measured while continuously changing the shear rate within the range of . Here, the viscosity value is the viscosity at a shear rate of 10 (1/s).
• Viscosities of the first and second agents The viscosity V1 and V2 of the first agent and the second agent were measured by the following method. Using a rheometer "MCR-302e" manufactured by Anton Paar, the temperature of the sample was adjusted to 25°C with a Peltier plate, and a shear rate of 0.0001 to 100 (1/s) was adjusted using a parallel plate with a diameter of 25 mm. Viscosity measurements were carried out while varying the shear rate continuously over a range. The viscosity at shear rates of 0.0001 (1/s), 3.16 (1/s), and 6.31 (1/s) is shown in the table.
• the first and second agents were filled into a 50cc two-liquid parallel cartridge (MIXPAC's 1:1 mixing cartridge "CDA050-01-PP"), and a static mixer (two-liquid mixing static mixer "MA6.3") was filled with the first and second agents. -12S", number of elements 6.3 mm x 12, discharge port inner diameter 1.5 mm), the thermally conductive composition (mass ratio 1:1) was mixed so that the sample thickness was 2 mm.
• a PET film (“SG2” manufactured by Panac Corporation) that has been subjected to mold release treatment, and then apply another PET film (“SG2” manufactured by Panac Corporation) on top of the sample.
• Sample 1A was obtained by leaving it for 24 hours at a temperature of 25° C. and a humidity of 50% RH. Five sheets of 30 mm square were punched out from the obtained sample 1A and stacked on top of each other, and the type E hardness was measured and the hardness was set as E1.
• Sample 2A obtained in the same manner as above was placed inside a constant temperature bath set at 150° C. and left in the constant temperature bath for 250 hours. Sample 2A after being left for 250 hours was taken out from the constant temperature bath and cooled to 25° C., and the type E hardness of sample 2A was measured, giving a hardness of E2.
• Type E hardness was measured for Sample 2A-2 and Sample 3A, which were obtained in the same manner except that the time they were left in the thermostatic chamber was changed to 500 hours and 1000 hours. It was named E3.
• E2/E1 and hardness change (E3) - (E2-2) were also determined from the obtained hardnesses E1, E2, and E3.
• the type E hardness was measured using a type E hardness meter according to JIS K 6253.
• Thermal resistance of cured product of thermally conductive composition The first and second agents were filled into a 50cc two-liquid parallel cartridge (MIXPAC's 1:1 mixing cartridge "CDA050-01-PP"), and a static mixer (two-liquid mixing static mixer "MA6.3") was filled with the first and second agents. -12S", number of elements 6.3 mm x 12, discharge port inner diameter 1.5 mm), the thermally conductive composition (mass ratio 1:1) was mixed using , 1.0, 1.5 mm on the release surface of a release-treated PET film ("SG2" manufactured by Panac), and then apply another PET film ("SG2" manufactured by Panac) over the sample.
• MIXPAC's 1:1 mixing cartridge "CDA050-01-PP” two-liquid mixing static mixer
• Sample 1B was crushed and fixed so that the mold release surface was in contact with the sample.
• Sample 1B was obtained by leaving it for 24 hours at a temperature of 25° C. and a humidity of 50% RH, and the thermal resistance value (initial) of the obtained sample 1B was measured using a measuring device compliant with ASTM D5470-06.
• Sample 1B obtained in the same manner as above was placed inside a constant temperature bath set at 150° C. and left in the constant temperature bath for 250 hours. Sample 2B after being left for 250 hours was taken out from the thermostat, cooled to 25° C., and then the thermal resistance value (after heating) was measured in the same manner as above.
• the first and second agents were filled into a 50cc two-liquid parallel cartridge (MIXPAC's 1:1 mixing cartridge “CDA050-01-PP”), and a static mixer (two-liquid mixing static mixer "MA6.3") was filled with the first and second agents.
• -12S number of elements 6.3 mm x 12, discharge port inner diameter 1.5 mm
• the thermally conductive composition mass ratio 1:1
• the flat side of the heat sink 60 mm x 60 mm, 6 mm thick plate with 16 protrusions 24 mm high on one side, material: aluminum
• the pedestal 40 mm x 40 mm, 10 mm thick, material: (copper) surface and fixed it.
• the thermally conductive composition had a size of 40 mm x 40 mm x 1 mm.
• the thermally conductive composition was cured by being left at a temperature of 25° C. and a humidity of 50% RH for 24 hours to obtain a test sample.
• the initial thermal resistance value using the above sample was evaluated by the following method.
• a heater (“SCPU25 ⁇ 25” manufactured by Kashima Co., Ltd.) was placed in the recess of the heat insulating material (26 mm ⁇ 26 mm, 15 mm thick plate with a 1.7 mm deep recess formed in the center, 50 mm ⁇ 90 mm, 15 mm thick, material: HIPLA).
• thermocouple is inserted into a thermocouple insertion hole provided at the center of the heat sink and the pedestal, and the thermocouple is placed so that the tip of the thermocouple is directly above the center of the heater.
• the voltage of the heater was set to 0 to stop heating, and the test sample, which had been cooled to room temperature, was removed from the heat insulating material and a heat cycle test was conducted.
• the heat cycle test was carried out for 1000 hours, with one cycle consisting of leaving the sample at -40°C for 30 minutes, then increasing the temperature to 150°C and leaving it for 30 minutes.
• the test sample was taken out from the thermostatic chamber, left to stand until it reached room temperature, and then the thermal resistance value R2 after the heat cycle test was calculated using the same procedure as above.
• the change in thermal resistance value R2 after the heat cycle test (R2-R1)/R1 ⁇ 100 (%) is calculated, and the degree of deterioration of the thermal resistance value is determined based on the following criteria. It was evaluated by A: (R2-R1)/R1 ⁇ 100 was 10% or less, and the reliability was good. B: (R2-R1)/R1 ⁇ 100 was greater than 10% and less than 20%, and had reliability suitable for practical use. C: (R2-R1)/R1 ⁇ 100 was greater than 20%, and reliability was not good. D: Can not be evaluated due to no curing.
• Organopolysiloxane 1 Organopolysiloxane having vinyl groups at both ends of the molecular chain (vinyl group content 0.17 mmol/g, viscosity 410 mPa ⁇ s)
• Organopolysiloxane 3 Organopolysiloxane
• Organopolysiloxane 6 (component (B)): Organopolysiloxane having hydrosilyl groups at both ends of the molecular chain (hydrosilyl group content 1.3 mmol/g, viscosity 10 mPa ⁇ s)
• Organopolysiloxane 7 (component (B)): Organopolysiloxane having hydrosilyl groups at both ends of the molecular chain (hydrosilyl group content 0.333 mmol/g, viscosity 100 mPa ⁇ s)
• Organopolysiloxane 8 (component (B)): Organopolysiloxane having hydrosilyl groups at both ends of the molecular chain (hydrosilyl group content 0.329 mmol/g, viscosity 128 mPa ⁇ s)
• Organopolysiloxane 9 (component (B)): Organopolysiloxane having hydrosilyl groups at both ends
• Organopolysiloxane 10 (component (D)): Organopolysiloxane having a methacryloyl group at one end of the molecular chain (methacryloyl group content 0.10 mmol/g, viscosity 177 mPa ⁇ s)
• Organopolysiloxane 11 ((G-1) component): Dimethyl silicone oil that does not have hydrosilylation addition reaction groups (viscosity 101 mPa ⁇ s)
• Organopolysiloxane 12 ((G-2) component): Organopolysiloxane that does not have a hydrosilylation addition reaction group and has a trialkoxysilyl group at the end (viscosity 26 mPa ⁇ s)
• Platinum catalyst ((F) component) ⁇ Thermal conductive filler> Aluminum oxide 1 ((E) component): Spherical alumina (D50: 0.5 ⁇ m) Aluminum oxide 2 (component (E)): Spherical alumina (D50: 3 ⁇ m) Aluminum oxide 3 ((E) component): Spherical alumina (D50: 18 ⁇ m) Aluminum oxide 4 (component (E)): Spherical alumina (D50: 40 ⁇ m) Aluminum oxide 5 ((E) component): Spherical alumina (D50: 60 ⁇ m)
• Examples 1 to 12 Comparative Examples 1 to 7
• a first agent and a second agent were prepared according to the formulations shown in Tables 1 to 3 below. Using a thermally conductive composition obtained by mixing the first agent and the second agent, various physical properties were measured and various evaluations were performed.
• the total Vi content 1 is the total content of alkenyl groups and methacryloyl groups with respect to the total amount of organopolysiloxanes 1 to 10 in each of the first and second agents.
• the total Vi content 2 is the total content of vinyl groups and methacryloyl groups based on the total amount of the thermally conductive composition (first part and second part).
• the amount of hydrosilyl groups 1 is the content of hydrosilyl groups relative to the total amount of organopolysiloxanes 1 to 10.
• the amount of hydrosilyl groups 2 is the content of hydrosilyl groups based on the total amount of the thermally conductive composition (first part and second part).
• the thermally conductive compositions of Examples 1 to 12 above contain components (A) to (F), have a Raman intensity ratio p2/p1 of more than 3.00, and have component (B) and ( Component C) was blended so that the hydrosilyl group concentration ratio b/(b+c) was greater than 0.45.
• the type E hardness (E2) after being left at 25° C. for 24 hours and further left at 150° C. for 250 hours was less than 70. Therefore, the flexibility of the cured product was maintained well even in an environment of 150°C, and the reliability was good. , it was possible to suppress the occurrence of peeling from the heating element, heat radiating element, etc., and suppress the increase in thermal resistance.
• the thermally conductive compositions of Comparative Examples 1 to 7 did not contain component (D) or had a Raman intensity ratio p2/p1 of 3.00 or less, and also contained component (B) and (C ) components were not blended so that the hydrosilyl group concentration ratio b/(b+c) was greater than 0.45. Therefore, in Comparative Examples 1 to 6, the flexibility of the cured product could not be maintained well in an environment of 150°C or higher, and the reliability was poor. When used as a thermally conductive member, peeling occurs from a heat generating element, a heat radiating element, etc., and an increase in thermal resistance cannot be suppressed. Furthermore, in Comparative Example 7, curing failure occurred.

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