JP2019021688A - Thermally conductive sheet - Google Patents

Abstract

To provide a thermally conductive sheet having sufficiently high thermal conductivity and hard to cause displacement in an in-plane direction.SOLUTION: A thermally conductive sheet comprises: a first region formed by a first material including a resin and a thermally conductive filler; and a second region formed by a second material having a Mooney viscosity (ML, 100°C) of 2 or more, and an adhesive force of 5.0 N/mm or more. In the thermally conductive sheet, an areal percentage occupied by the second region in at least one principal face is over 0% and under 20%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat conductive sheet.

  In recent years, electronic components such as plasma display panels (PDP) and integrated circuit (IC) chips have increased in heat generation as performance is improved. As a result, in electronic devices using electronic components, it is necessary to take measures against functional failures due to temperature rise of the electronic components.

  As countermeasures against functional failures due to temperature rise of electronic components, generally, a method of promoting heat dissipation by attaching a heat sink such as a metal heat sink, heat sink, heat sink or the like to a heat generator such as an electronic component is adopted. ing. And when using a radiator, in order to efficiently transfer heat from the heater to the radiator, heat is usually generated with a sheet-like member (heat conductive sheet) having high thermal conductivity interposed. The body and the radiator are in close contact.

  Therefore, the heat conductive sheet used by being sandwiched between the heat generating body and the heat radiating body is required to exhibit excellent heat conductivity.

  Therefore, for example, in Patent Document 1, as a heat conductive sheet having high heat conductivity, a pre-heat conductive sheet formed by pressing a composition containing a fluororesin and expanded graphite into a sheet shape in the thickness direction is used. There has been proposed a heat conductive sheet obtained by slicing a laminated body obtained by laminating a plurality of sheets or by folding or winding at an angle of 45 ° or less with respect to the laminating direction. Moreover, in patent document 1, it is the state of the laminated body obtained by laminating | stacking, folding, or winding a pre heat conductive sheet in the state which apply | coated the adhesive agent on the surface, or the state which provided the adhesive layer on the surface. It has also been proposed to sufficiently suppress delamination. And as for the heat conductive sheet of this patent document 1, the strip (The slice piece of the pre heat conductive sheet which comprised the laminated body) containing a fluororesin and expanded graphite is paralleled through arbitrary adhesive agents or an adhesive layer. Since it has the structure formed by joining and each strip contains the fluororesin and the expanded graphite, high thermal conductivity can be exhibited.

International Publication No. 2016/185688

  Here, when the heat conductive sheet is transported in a state where the heat conductive sheet is adhered to an adherend such as a heat generating element, or when the heat generating element and the heat radiating element are brought into close contact with the heat conductive sheet interposed therebetween. For example, it is also required not to cause a positional shift in an in-plane direction (a direction parallel to the surface of the heat conductive sheet).

  However, the conventional heat conductive sheet has room for improvement in that it is difficult to cause positional displacement while ensuring heat conductivity.

  Therefore, an object of the present invention is to provide a heat conductive sheet that has a sufficiently high thermal conductivity and hardly causes positional displacement in the in-plane direction.

  The present inventor has intensively studied for the purpose of solving the above problems. And this inventor discovered that if the area | region which has a predetermined | prescribed property was provided in a predetermined | prescribed ratio in a heat conductive sheet, generation | occurrence | production of the position shift | offset | difference of an in-plane direction could be suppressed, ensuring thermal conductivity, Completed the invention.

That is, the present invention aims to advantageously solve the above-mentioned problems, and the heat conductive sheet of the present invention includes a first region comprising a first material containing a resin and a heat conductive filler, Mooney A second region having a viscosity (ML _{1 + 4} , 100 ° C.) of 2 or more and having an adhesive strength of 5.0 N / mm or more, and the second region on at least one main surface is The area ratio is more than 0% and less than 20%. Thus, if the 1st area | region containing a heat conductive filler is provided, sufficiently high heat conductivity can be ensured. Further, if a second region made of a second material having a predetermined property and having a predetermined adhesive force is provided, the occurrence of positional displacement in the in-plane direction is suppressed while maintaining the shape of the heat conductive sheet. be able to. Furthermore, if the area ratio of the second region is within a predetermined range, it is possible to suppress a decrease in the thermal conductivity of the heat conductive sheet.
Here, in the present invention, the “Mooney viscosity” can be measured at a temperature of 100 ° C. in accordance with JIS K6300. The “adhesive strength” can be measured by using a probe tack tester and pressing the probe for 10 seconds under the conditions of a temperature of 25 ° C. and a load of 0.5 N.

  Here, in the heat conductive sheet of the present invention, the area ratio occupied by the second region is preferably 1% or more and 15% or less. If the area ratio which a 2nd area | region occupies is in the said range, the thermal conductivity of a heat conductive sheet can fully be improved, suppressing generation | occurrence | production of the position shift | offset | difference of an in-plane direction still more favorably.

  In the heat conductive sheet of the present invention, the resin is preferably made of at least one of a fluororesin and a silicon resin. If the resin of the first material is a fluororesin and / or a silicon resin, the flame retardancy of the heat conductive sheet can be increased.

  Furthermore, in the heat conductive sheet of the present invention, it is preferable that the second material includes an adhesive resin and a heat conductive filler. If a second material containing an adhesive resin and a thermally conductive filler is used, the adhesiveness of the second region is sufficiently increased while sufficiently suppressing the thermal conductivity of the thermal conductive sheet from being lowered. Generation | occurrence | production of the position shift of an inner direction can further be suppressed.

  Here, it is preferable that the content rate of the said heat conductive filler in said 2nd material is 1.0 mass% or more and 20.0 mass% or less. If the content ratio of the heat conductive filler in the second material is within the above range, the heat conductivity of the heat conductive sheet is sufficiently increased while sufficiently suppressing the adhesive strength of the second region from being lowered. Can do.

Furthermore, it is preferable that the thermally conductive filler in the second material includes a fibrous carbon nanomaterial, and the BET specific surface area of the fibrous carbon nanomaterial is 400 m ² / g or more and 2500 m ² / g or less. . If the BET specific surface area of the fibrous carbon nanomaterial is within the above range, the adhesive strength of the second region and the thermal conductivity of the thermal conductive sheet can be sufficiently increased.
In the present invention, the “BET specific surface area” refers to a nitrogen adsorption specific surface area measured using the BET method.

In the heat conductive sheet of the present invention, it is preferable that the heat conductive filler in the first material includes a particulate material having a volume average particle diameter of 150 μm or more and 300 μm or less. If a heat conductive filler containing a particulate material having a volume average particle diameter of 150 μm or more and 300 μm or less is used as the heat conductive filler of the first material, the heat conductivity of the heat conductive sheet can be sufficiently increased.
In the present invention, the “volume average particle diameter” refers to a maximum value (mode diameter) in a volume-based particle diameter distribution measured using a laser diffraction method. The measurement of the volume average particle diameter of the particulate material is not particularly limited. For example, it is optional to dissolve the resin using a good solvent for the resin contained in the first material constituting the first region. The particulate material can be taken out from the first region by using the above method.

  And as for the heat conductive sheet of this invention, it is preferable that the content rate of the said particulate material in said 1st material is 5 volume% or more and 30 volume% or less. If the content rate of a particulate material is in the said range, the heat conductivity of a heat conductive sheet can fully be improved, ensuring the softness | flexibility of a heat conductive sheet, and the adhesiveness with respect to a to-be-adhered body sufficiently.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the heat conductive sheet which has high heat conductivity and does not raise | generate the position shift of an in-plane direction easily.

It is a top view which shows typically an example of the heat conductive sheet according to this invention. It is a top view which shows typically the other example of the heat conductive sheet according to this invention. It is a perspective view which shows typically the laminated body used for manufacture of the heat conductive sheet shown in FIG. It is a perspective view which shows typically the laminated body used for manufacture of the heat conductive sheet shown in FIG. (A)-(f) is a top view which shows typically the structure of the heat conductive sheet of an Example and a comparative example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, what attached | subjected the same code | symbol shall show the same component. Moreover, in each figure, in order to understand easily, the magnitude | size of each component is expanded or reduced suitably, and is shown.

(Heat conduction sheet)
Here, the heat conductive sheet of the present invention can be used by being sandwiched between the heat generator and the heat radiator, for example, when the heat radiator is attached to the heat generator. That is, the heat conductive sheet of this invention can comprise a heat radiating device as a heat radiating member with heat sinks, such as a heat sink, a heat sink, and a heat radiating fin.

And the heat conductive sheet of this invention consists of a 1st area | region which consists of a 1st material containing resin and a heat conductive filler, and a Mooney viscosity (ML1 ₊ 4,100 degreeC) is 2 or more second materials, and A second region having an adhesive strength of 5.0 N / mm or more. In the heat conductive sheet of the present invention, the area ratio occupied by the second region is at least 0% and less than 20% in at least one, preferably both, of the main surface which is a surface orthogonal to the thickness direction of the heat conductive sheet. It is characterized by.

Specifically, the heat conductive sheet of the present invention has, for example, a first region 11 made of the first material and a second region 12 made of the second material, as shown in FIG. 1, FIG. 2, or FIG. doing. And in the at least one main surface of the heat conductive sheet 10, the ratio of the total of the area which the 2nd area | region 12 occupies is less than 20%.
In addition, the shape and arrangement | positioning of the 1st area | region 11 and the 2nd area | region 12 are not limited to the shape and arrangement | positioning shown to FIG. And it is preferable that the 1st area | region 11 and the 2nd area | region 12 each extend over the full length of the thickness direction of the heat conductive sheet 10 (namely, over both main surfaces). Furthermore, it is preferable that the shapes of the first region 11 and the second region 12 do not change in the thickness direction of the heat conductive sheet 10, and the area ratio occupied by the second region 12 is one main surface side and the other main surface side. And are preferably the same. In addition to the first region 11 and the second region 12, the heat conductive sheet 10 may further include a region made of a material other than the first material and the second material, but from the viewpoint of the productivity of the heat conductive sheet. From the above, it is preferable that the heat conductive sheet includes only the first region 11 and the second region 12.

  And since the heat conductive sheet of this invention has the 1st area | region containing a heat conductive filler, it can ensure sufficiently high heat conductivity. Moreover, since the heat conductive sheet of the present invention is made of the second material having a predetermined property and has a second region having a predetermined adhesive force, the surface of the heat conductive sheet is maintained while maintaining the shape of the heat conductive sheet. Generation | occurrence | production of the position shift of an inner direction can be suppressed. Furthermore, since the area ratio of a 2nd area | region is in the predetermined range, the heat conductive sheet of this invention can be compatible with ensuring thermal conductivity and suppressing generation | occurrence | production of the position shift of an in-plane direction.

<First area>
Here, the first region is composed of a first material containing a resin and a thermally conductive filler. And since the 1st material contains the heat conductive filler, the heat conductive sheet which has the 1st area | region which consists of a 1st material can ensure heat conductivity.
In addition, if the 1st area | region contained in a heat conductive sheet is comprised with the 1st material containing resin and a heat conductive filler, it may be comprised only with 1 type of 1st materials, or 2 You may be comprised with the 1st material of the kind or more. Further, the first region made of the first material usually has a lower adhesive force than the second region made of the second material. And the adhesive force of a 1st area | region may be less than 5.0 N / mm, for example, can be 4.0 N / mm or less.

[First material]
The first material constituting the first region contains a resin and a thermally conductive filler. The first material may further contain an additive such as a flame retardant or a plasticizer, but from the viewpoint of preventing the additive from bleeding out or blooming, the first material should not contain an additive. Is preferred.

-Resin-
The resin constitutes the matrix resin in the first region and also functions as a binder for binding the heat conductive filler.
As the resin, at least one of a resin that is liquid at normal temperature and pressure and a resin that is solid at normal temperature and pressure can be used. In this specification, “normal temperature” refers to 23 ° C., and “normal pressure” refers to 1 atm (absolute pressure).

  Here, examples of the resin that is liquid under normal temperature and normal pressure include a thermoplastic resin that is liquid under normal temperature and normal pressure, and a thermosetting resin that is liquid under normal temperature and normal pressure. Among these, from the viewpoint of improving the adhesion between the heat conductive sheet and the adherend when using the heat conductive sheet and enabling good conduction of heat through the heat conductive sheet, it is a liquid resin at room temperature and normal pressure. It is preferable to use a thermoplastic resin that is liquid at normal temperature and pressure.

  Examples of the thermoplastic resin that is liquid at room temperature and normal pressure include acrylic resin, epoxy resin, silicon resin, and fluororesin. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the thermosetting resin that is liquid at normal temperature and pressure include natural rubber; butadiene rubber; isoprene rubber; nitrile rubber; hydrogenated nitrile rubber; chloroprene rubber; ethylene propylene rubber; Butyl rubber; Halogenated butyl rubber; Polyisobutylene rubber; Epoxy resin; Polyimide resin; Bismaleimide resin; Benzocyclobutene resin; Phenolic resin; Unsaturated polyester; Type-modified polyphenylene ether; and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the resin that is solid under normal temperature and normal pressure include a thermoplastic resin that is solid under normal temperature and normal pressure, and a thermosetting resin that is solid under normal temperature and normal pressure. Among these, from the viewpoint of improving the adhesion between the heat conductive sheet and the adherend, it is preferable to use a thermoplastic resin that is solid at normal temperature and pressure as the solid resin at normal temperature and pressure.

  Examples of the thermoplastic resin that is solid at normal temperature and pressure include, for example, poly (2-ethylhexyl acrylate), a copolymer of acrylic acid and 2-ethylhexyl acrylate, polymethacrylic acid or an ester thereof, polyacrylic acid or an ester thereof. Acrylic resin such as: silicone resin; fluororesin; polyethylene; polypropylene; ethylene-propylene copolymer; polymethylpentene; polyvinyl chloride; polyvinylidene chloride; polyvinyl acetate: ethylene-vinyl acetate copolymer; Polyethylene terephthalate; polybutylene terephthalate; polyethylene naphthalate; polystyrene; polyacrylonitrile; styrene-acrylonitrile copolymer; acrylonitrile-butadiene-styrene copolymer (ABS resin) Styrene-butadiene block copolymer or hydrogenated product thereof; styrene-isoprene block copolymer or hydrogenated product thereof; polyphenylene ether; modified polyphenylene ether; aliphatic polyamides; aromatic polyamides; Polysulfone; Polyethersulfone; Polyethernitrile; Polyetherketone; Polyketone; Polyurethane; Liquid crystal polymer; Ionomer; These may be used individually by 1 type and may use 2 or more types together.

  Examples of the thermosetting resin that is solid at room temperature and normal pressure include natural rubber; butadiene rubber; isoprene rubber; nitrile rubber; hydrogenated nitrile rubber; chloroprene rubber; ethylene propylene rubber; Butyl rubber; Halogenated butyl rubber; Polyisobutylene rubber; Epoxy resin; Polyimide resin; Bismaleimide resin; Benzocyclobutene resin; Phenolic resin; Unsaturated polyester; Type-modified polyphenylene ether; and the like. These may be used individually by 1 type and may use 2 or more types together.

  Among the above, from the viewpoint of increasing the flame retardancy of the heat conductive sheet, it is preferable to use at least one of a fluororesin and a silicon resin as the resin, and more preferably a fluororesin.

Examples of the fluororesin that is liquid at normal temperature and pressure include, for example, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropentene-tetrafluoroethylene terpolymer, perfluoropropene oxide polymer, A tetrafluoroethylene-propylene-vinylidene fluoride copolymer or the like can be used.
Examples of commercially available fluororesins that are liquid at room temperature and normal pressure include, for example, Viton (registered trademark) LM manufactured by DuPont, Daiel (registered trademark) G-101 manufactured by Daikin Industries, Ltd., and 3M Examples include Dinion FC2210 manufactured by Shin-Etsu Chemical Co., Ltd. and SIFEL series manufactured by Shin-Etsu Chemical Co., Ltd.

Further, examples of the fluororesin that is solid at normal temperature and pressure include, for example, polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer. Polymer, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene-chlorofluoroethylene copolymer, tetrafluoroethylene-perfluorodioxole copolymer, polyvinyl fluoride, tetrafluoroethylene-propylene copolymer, vinylidene fluoride Ride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, polytetrafluoroethylene acrylic modified product, Ester-modified product of La fluoroethylene, epoxy-modified products of polytetrafluoroethylene and polytetrafluoroethylene silane modified product or the like can be used.
Examples of commercially available fluororesins that are solid at room temperature and normal pressure include, for example, Daiel (registered trademark) G-912, G-700 series, Daiel G-550 series / G-600 series manufactured by Daikin Industries, Ltd. And DYNAR (registered trademark) series, KYNAR FLEX (registered trademark) series manufactured by ALKEMA; Dyneon FC2211, FPO3600ULV manufactured by 3M; and the like.

  The content ratio of the resin in the first material is not particularly limited, and is, for example, preferably 50% by volume or more, more preferably 70% by volume or more, and 95% by volume or less. Is preferable, and it is more preferable that it is 80 volume% or less. If the resin content is equal to or higher than the above lower limit, the flexibility of the first region can be increased, so that the adhesion of the heat conductive sheet having the first region to the adherend can be increased. Moreover, if the resin content is less than or equal to the above upper limit, the thermal conductivity of the thermal conductive sheet having the first region and the first region can be sufficiently increased by sufficiently containing the thermal conductive filler. It is.

-Thermally conductive filler-
The thermally conductive filler imparts excellent thermal conductivity to the first region made of the first material. The heat conductive filler is not particularly limited, and known heat conductive fillers such as a particulate material having thermal conductivity and a fibrous material having thermal conductivity can be used. Among these, as the thermally conductive filler of the first material, it is preferable to use a carbon material such as a particulate carbon material and a fibrous carbon material, and it is more preferable to use a particulate carbon material. In addition, a heat conductive filler may be used individually by 1 type, and may use 2 or more types together.

Examples of the particulate material having thermal conductivity include alumina particles, zinc oxide particles, boron nitride particles, aluminum nitride particles, silicon nitride particles, silicon carbide particles, magnesium oxide particles, and particulate carbon materials. Among these, boron nitride particles and a particulate carbon material are preferable, and a particulate carbon material is more preferable.
In addition, the particulate material which has heat conductivity may be used individually by 1 type, and may use 2 or more types together.

Here, the particulate carbon material suitable as the particulate material having thermal conductivity is not particularly limited, for example, artificial graphite, flake graphite, exfoliated graphite, natural graphite, acid-treated graphite, expansibility Graphite, graphite such as expanded graphite, carbon black, and the like can be used. These may be used individually by 1 type and may use 2 or more types together.
Among them, it is preferable to use expanded graphite as the particulate carbon material. This is because if expanded graphite is used, the thermal conductivity of the heat conductive sheet having the first region and the first region can be further improved.

  The expanded graphite can be obtained, for example, by expanding the expanded graphite obtained by chemically treating graphite such as flake graphite with sulfuric acid or the like, and then making it finer. Examples of expanded graphite include EC1500, EC1000, EC500, EC300, EC100, and EC50 (all trade names) manufactured by Ito Graphite Industries.

  The volume average particle diameter of the particulate material having thermal conductivity is preferably 50 μm or more, more preferably 150 μm or more, preferably 300 μm or less, and more preferably 200 μm or less. . If the average particle diameter of the particulate material having thermal conductivity is within the above range, the heat conduction path of the particulate material is well formed in the first region, and the heat conduction sheet having the first region and the first region This is because excellent thermal conductivity can be exhibited.

Further, the aspect ratio (major axis / minor axis) of the particulate material having thermal conductivity is preferably 1 or more and 10 or less, and more preferably 1 or more and 5 or less.
The “aspect ratio of the particulate material” refers to a cross section in the thickness direction of the heat conductive sheet observed with a scanning electron microscope (SEM). It can be determined by measuring the particle diameter (minor axis) in the direction perpendicular to the diameter and calculating the average value of the ratio of the major axis to the minor axis (major axis / minor axis).

  The fibrous material having thermal conductivity is not particularly limited, and for example, carbon nanotubes, vapor-grown carbon fibers, carbon fibers obtained by carbonizing organic fibers, and cut products thereof are used. be able to. These may be used individually by 1 type and may use 2 or more types together.

The aspect ratio (major axis / minor axis) of the fibrous material having thermal conductivity is preferably more than 10.
The “aspect ratio of the fibrous material” is the maximum diameter (major diameter) of 100 randomly selected fibrous materials using a TEM (transmission electron microscope) and the outer diameter in the direction perpendicular to the maximum diameter. It can be determined by measuring (minor axis) and calculating the average value of the ratio of major axis to minor axis (major axis / minor axis).

  Among the above, as the fibrous material having thermal conductivity, it is preferable to use a fibrous carbon nanomaterial such as a carbon nanotube (hereinafter sometimes referred to as “CNT”). It is more preferable to use a material.

Here, the fibrous carbon nanomaterial containing CNT, which can be suitably used as a fibrous material having thermal conductivity, may be composed only of CNT, or CNT and fibrous carbon nanomaterial other than CNT. It may be a mixture with the material.
The CNTs in the fibrous carbon nanomaterial are not particularly limited, and single-walled carbon nanotubes and / or multi-walled carbon nanotubes can be used. CNTs are single-walled to carbon-walled carbon nanotubes. It is preferable that there is a single-walled carbon nanotube.

Further, the average diameter (Av) of the fibrous carbon nanomaterial is preferably 0.5 nm or more, more preferably 1 nm or more, preferably 15 nm or less, and more preferably 10 nm or less. . This is because if the average diameter (Av) of the fibrous carbon nanomaterial is equal to or more than the lower limit, aggregation of the fibrous carbon nanomaterial can be suppressed and dispersibility of the fibrous carbon nanomaterial can be improved. Moreover, if the average diameter (Av) of the fibrous carbon nanomaterial is 15 nm or less, the thermal conductivity and strength of the thermal conductive sheet can be sufficiently increased.
The “average diameter (Av) of fibrous carbon nanomaterial” is obtained by measuring the diameter (outer diameter) of 100 randomly selected fibrous carbon nanomaterials using a TEM (transmission electron microscope). Can be sought.

Furthermore, the average length of the fibrous carbon nanomaterial is preferably 0.1 μm or more, more preferably 1 μm or more, and preferably 5000 μm or less.
In the present invention, “average length of fibrous carbon nanomaterial” is measured by measuring the maximum diameter (major diameter) of 100 randomly selected fibrous carbon nanomaterials using a TEM (transmission electron microscope). It can be obtained by calculating an average value.

The BET specific surface area of the fibrous carbon nanomaterial is preferably 400 m ² / g or more, more preferably 600 m ² / g or more, and preferably 2500 m ² / g or less. This is because if the BET specific surface area of the fibrous carbon nanomaterial is greater than or equal to the above lower limit, the thermal conductivity and strength of the thermal conductive sheet can be sufficiently increased. Moreover, it is because aggregation of fibrous carbon nanomaterial can be suppressed if the BET specific surface area of fibrous carbon nanomaterial is below the said upper limit.

Further, the fibrous carbon nanomaterial having the above-described properties is not particularly limited, and a chemical compound is supplied by supplying a raw material compound and a carrier gas onto a substrate having a catalyst layer for CNT production on the surface. When synthesizing CNTs by the phase growth method (CVD method), a method of dramatically improving the catalytic activity of the catalyst layer by making a small amount of oxidizing agent (catalyst activation material) present in the system (super growth method) It is preferable to use fibrous carbon nanomaterials containing CNTs manufactured according to WO 2006/011655). Hereinafter, the carbon nanotube obtained by the super growth method may be referred to as “SGCNT”.
Here, the fibrous carbon nanomaterial containing SGCNT produced by the super-growth method may be composed only of SGCNT, and in addition to SGCNT, other carbon nano-materials such as non-cylindrical carbon nanostructures may be used. A structure may be included.

  And the content rate of the heat conductive filler in a 1st material is not specifically limited, For example, it is preferable that it is 5 volume% or more, it is more preferable that it is 20 volume% or more, and 50 volume%. Or less, more preferably 30% by volume or less. If the content ratio of the heat conductive filler is equal to or more than the above lower limit, the heat conductive filler is sufficiently contained to sufficiently increase the heat conductivity of the heat conductive sheet having the first region and the first region. Because it can. Moreover, if the content rate of a heat conductive filler is below the said upper limit, since the softness | flexibility of a 1st area | region can be improved, the adhesiveness with respect to the to-be-adhered body of the heat conductive sheet which has a 1st area | region can be improved. Because it can.

  In particular, when the thermally conductive filler of the first material includes a particulate material having a volume average particle diameter of 150 μm to 300 μm, the particulate material having a volume average particle diameter of 150 μm to 300 μm in the first material. The content of is preferably 5% by volume or more, more preferably 20% by volume or more, preferably 50% by volume or less, and more preferably 30% by volume or less. If the content ratio of the particulate material is not less than the above lower limit, the thermal conductivity of the heat conductive sheet can be sufficiently increased, and if the content ratio of the particulate material is not more than the above upper limit, the heat conductive sheet is covered. This is because the adhesion to the body can be improved.

[Area ratio]
And the ratio of the sum total of the area which a 1st area | region occupies in at least one main surface of a heat conductive sheet is more than 80% and less than 100% normally, it is preferable that it is 85% or more, and it is 90% or more. More preferably, it is 99% or less, and more preferably 98.75% or less. If the area ratio of a 1st area | region is more than the said lower limit, the heat conductivity of a heat conductive sheet can fully be improved. Further, if the area ratio of the first region is equal to or less than the above upper limit value, the area of the second region having a high adhesive force can be sufficiently ensured, so that the main surface side satisfying the area ratio is in close contact with the adherend. It is possible to satisfactorily suppress the occurrence of positional deviation in the in-plane direction of the heat conductive sheet when it is made to occur.

[shape]
In addition, the shape of the 1st area | region in a heat conductive sheet is not specifically limited, It can be set as arbitrary shapes. Specifically, for example, as shown in FIG. 1 and FIGS. 5A, 5B, 5E, and 5F, the shape surrounding the island-like second region 12 (sea shape) as shown in a plan view shape. For example, as shown in a plan view shape in FIGS. 2 and 5C and 5D, a rectangular shape divided by the second region 12 may be used. And the number of the 1st area | region which exists in a heat conductive sheet may be one, and two or more may be sufficient as it.

<Second area>
The second region is composed of a second material having a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 2 or more. And the 2nd area | region mainly bears the function which suppresses the position shift of the in-plane direction of a heat conductive sheet, and requires that adhesive force is 5.0 N / mm or more.
In addition, the 2nd area | region contained in a heat conductive sheet may be comprised only with one type of 2nd material, if Mooney viscosity (ML1 _{+ 4} , 100 degreeC) is comprised with 2 or more 2nd materials. And you may be comprised with 2 or more types of 2nd materials. And the 2nd area | region which consists of a 2nd material has a heat conductivity normally lower than the 1st area | region which consists of a 1st material.

[Second material]
As long as the second material constituting the second region has a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 2 or more and the adhesive strength of the second region can be 5.0 N / mm or more. There is no particular limitation. Among these, as the second material, a resin composition containing an adhesive resin or an adhesive resin and a thermally conductive filler and optionally further containing an additive such as a flame retardant or a plasticizer is preferable. The resin composition may contain an additive such as a flame retardant or a plasticizer. However, from the viewpoint of preventing the additive from bleeding out or blooming, the resin composition may not contain an additive. preferable.
The second material is usually made of a material different from the first material.

-Adhesive resin-
The adhesive resin constitutes a matrix resin in the second region and imparts a desired adhesive force to the second region. In addition, when the second material contains a heat conductive filler, the adhesive resin also functions as a binder for binding the heat conductive filler.

  The adhesive resin is not particularly limited, and for example, an acrylic resin that is solid under normal temperature and normal pressure or a resin that is liquid under normal temperature and normal pressure can be used. In this specification, “normal temperature” refers to 23 ° C., and “normal pressure” refers to 1 atm (absolute pressure).

Here, as the resin that is liquid under normal temperature and normal pressure, a resin that is liquid under normal temperature and normal pressure similar to those exemplified as the first material resin and preferred examples thereof can be used.
Among them, from the viewpoint of increasing the flame retardancy of the heat conductive sheet, it is preferable to use at least one of a fluororesin that is liquid at normal temperature and pressure and a silicon resin that is liquid at normal temperature and pressure as the resin that is liquid at normal temperature and pressure. It is more preferable to use a liquid fluororesin at room temperature and normal pressure.

  And the content rate of the adhesive resin in 2nd material is not specifically limited, For example, it is preferable that it is 80 mass% or more, it is more preferable that it is 90 mass% or more, and it is 93 mass% or more. More preferably, it is preferably less than 100% by mass, and more preferably 97% by mass or less. This is because if the content ratio of the adhesive resin is equal to or more than the above lower limit, the adhesive force of the second region can be sufficiently increased, and the positional deviation in the in-plane direction of the heat conductive sheet can be suppressed. Moreover, if the content rate of adhesive resin is below the said upper limit, a heat conductive filler can be contained and it can suppress that the heat conductivity of the heat conductive sheet which has a 2nd area | region falls. is there.

-Thermally conductive filler-
The thermally conductive filler of the second material suppresses a decrease in the thermal conductivity of the second region made of the second material.
And as a heat conductive filler of a 2nd material, the heat conductive filler similar to what was illustrated as a heat conductive filler of a 1st material and its suitable example can be used. Among them, as the heat conductive filler of the second material, it is preferable to use a carbon material such as a particulate carbon material and a fibrous carbon material, and it is more preferable to use a particulate carbon material and / or a fibrous carbon material. It is more preferable to use a fibrous carbon nanomaterial, and it is particularly preferable to use a fibrous carbon nanomaterial having a BET specific surface area of 400 m ² / g or more and 2500 m ² / g or less.

  And the content rate of the heat conductive filler in 2nd material is not specifically limited, For example, it is preferable that it is more than 0 mass%, and it is more preferable that it is 3.0 mass% or more, 20 The content is preferably 0.0% by mass or less, more preferably 10.0% by mass or less, and still more preferably 7.0% by mass or less. It is because it can suppress that the heat conductivity of the heat conductive sheet which has a 2nd area | region falls if the content rate of a heat conductive filler is more than the said minimum. Moreover, if the content rate of a heat conductive filler is below the said upper limit, it is because the adhesive force of a 2nd area | region can fully be ensured and the position shift of the in-plane direction of a heat conductive sheet can be suppressed.

  In particular, when the thermally conductive filler of the second material includes a fibrous carbon nanomaterial, the content ratio of the fibrous carbon nanomaterial in the second material is preferably 1.0% by mass or more. 3.0 mass% or more, more preferably 10.0 mass% or less, and even more preferably 7.0 mass% or less. If the content ratio of the heat conductive filler is equal to or higher than the above lower limit, the heat conductivity of the heat conductive sheet can be sufficiently suppressed from decreasing, and the content ratio of the heat conductive filler is equal to or lower than the above upper limit. This is because the positional deviation in the in-plane direction of the heat conductive sheet can be sufficiently suppressed.

-Mooney viscosity-
The second material needs to have a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 2 or more, and the Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the second material is preferably 10 or more. Or less, more preferably 50 or less. This is because when the Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the second material is less than 2, it is difficult to maintain the shape of the heat conductive sheet. In addition, if the Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the second material is within the above range, the adhesive strength of the second region made of the second material can be set to an appropriate level.

[Adhesive force]
The second region made of the second material requires an adhesive strength of 5.0 N / mm or more, and the adhesive strength of the second region is 9.0 N / mm or more and 20.0 N / mm or less. Is preferred. This is because when the adhesive force of the second region is less than 5.0 N / mm, the positional deviation in the in-plane direction of the heat conductive sheet cannot be suppressed. Further, if the adhesive strength of the second region is within the above range, it is possible to suppress a decrease in manufacturability of the heat conductive sheet due to the stickiness of the second material while ensuring the adhesive strength, and in the in-plane direction. This is because it is possible to easily manufacture a heat conductive sheet that can satisfactorily suppress the positional deviation.

[Area ratio]
And the ratio of the sum total of the area which a 2nd area | region occupies in at least one main surface of a heat conductive sheet needs to be less than 20%, It is preferable that it is 1% or more, and it is 1.25% or more. Is more preferable, 15% or less is preferable, and 10% or less is more preferable. If the area ratio of a 2nd area | region is less than 20%, the area of a 1st area | region can fully be ensured and the heat conductivity of a heat conductive sheet can fully be improved. Further, if the area ratio of the second region is equal to or more than the lower limit, when the main surface side satisfying the area ratio is brought into close contact with the adherend, the positional deviation in the in-plane direction of the heat conductive sheet is favorably generated. Can be suppressed.

[shape]
In addition, the shape of the 2nd area | region in a heat conductive sheet is not specifically limited, It can be set as arbitrary shapes. Specifically, the shape of the second region is such that, for example, the heat conductive sheet 10 is in the first region as shown in FIGS. 1 and 5 (a), (b), (e), and (f) in plan view. You may make it the shape used as the sea island structure which has the sea part which consists of 11 and the island part which consists of the 2nd area | region 12. In this case, the second region 12 serving as an island may be surrounded by the first region 11 as shown in FIGS. 1 and 5A, 5E, and 5F. Only a part of the periphery may be surrounded by the first region 11 as shown in 5 (b). Moreover, the shape of the second region is a rectangular shape extending over the entire length in any one direction of the heat conductive sheet 10 as shown in plan view in FIGS. 2 and 5C and 5D. There may be. And the number of the 2nd area | region which exists in a heat conductive sheet may be one, and two or more may be sufficient as it.

<The manufacturing method of a heat conductive sheet>
And the heat conductive sheet of this invention is not specifically limited, For example, it can prepare using the method in any one of following (1)-(3). In the following, the “sheet” made of the first material or the second material includes a narrow-width sheet sometimes referred to as a “strip” and a short sheet.
(1) After preparing a sheet made of the first material and having a hole having a shape corresponding to the shape of the desired second region at the position where the second region is formed, the second material is filled into the hole of the sheet. Alternatively, a method of preparing a heat conductive sheet by embedding a sheet made of the second material in a hole of the sheet and joining the sheet made of the first material.
(2) A method of preparing a heat conductive sheet by separately preparing a sheet made of the first material and a sheet made of the second material, and then joining the sheets in parallel using a known technique such as adhesion. .
(3) After forming a laminate of a sheet made of the first material (sheet for the first region) and a sheet made of the second material (sheet for the second region), heat conduction is performed by slicing the laminate. A method of preparing a sheet.

Among these, from the viewpoint of ease of manufacture, the heat conductive sheet of the present invention is preferably manufactured by the method (3).
Specifically, for example, the heat conductive sheet 10 as shown in FIG. 1 can be manufactured by forming the laminate 20 as shown in FIG. 3 and then slicing the laminate 20 in the lamination direction. Here, the laminated body 20 shown in FIG. 3 includes a plurality of (four in the illustrated example) laminated structures in which the first region sheets 21 are laminated (two in the illustrated example) in the width direction (four in the illustrated example). It has a structure in which a pair of second region sheets (strips) 22 </ b> A that are spaced apart from each other in the left-right direction in the illustrated example.
For example, the heat conductive sheet 10 as shown in FIG. 2 can be manufactured by forming the laminated body 20 as shown in FIG. 4 and then slicing the laminated body 20 in the lamination direction. Here, the laminate 20 shown in FIG. 4 includes a first region between a plurality of (three in the illustrated example) laminated structures in which the first region sheets 21 are laminated in an arbitrary number (three in the illustrated example). The second region sheet 22 </ b> B having the same planar view size as that of the sheet for use 21 is interposed (in the illustrated example, one sheet between the laminated structures).

  And in the heat conductive sheet prepared by the method of (3), the slice piece of the first region sheet 21 is the first region described above, and the slice pieces of the second region sheets 22A, 22B are the first piece described above. There are two areas.

Here, the sheet | seat for 1st area | regions can be obtained by pressurizing the 1st material which contains resin and a heat conductive filler, and further contains an additive etc. and shape | molds it in a sheet form. And in the sheet | seat for 1st area | region formed by pressurizing 1st material and shape | molding in a sheet form, it is guessed that a heat conductive filler arranges mainly in an in-plane direction, and the heat conductivity of an in-plane direction improves especially. The
In addition, the 1st material mentioned above is not specifically limited, It can obtain by mixing the component mentioned above using known mixing apparatuses, such as a kneader, a roll, a mixer. The mixing may be performed in the presence of a solvent such as an organic solvent.
Further, the first material prepared as described above can be defoamed and crushed arbitrarily, and then formed into a sheet using a known forming method such as press forming, rolling forming or extrusion forming. In addition, when a solvent is used at the time of mixing, it is preferable to form the sheet after removing the solvent. For example, if defoaming is performed using vacuum defoaming, the solvent is simultaneously removed at the time of defoaming. It can be carried out.

  Further, the second region sheet can be obtained, for example, by pressurizing the second material and forming it into a sheet shape, similarly to the first region sheet.

And a laminated body can be obtained by laminating | stacking the sheet | seat for 1st area | regions and the sheet | seat for 2nd area | regions in arbitrary orders and arrangement | positioning.
Here, usually, in the laminate, the adhesive force between the surfaces of the sheets is sufficiently obtained by the pressure when the sheets are laminated. However, when the adhesive strength is insufficient or when it is necessary to sufficiently suppress delamination of the laminate, lamination may be performed in a state where the surface of the sheet is slightly dissolved with a solvent. You may further press the laminated body made into the lamination direction. In particular, when using a second area sheet having a width narrower than that of the first area sheet, when the plan view dimension of the first area sheet is different from the plan view dimension of the second area sheet, lamination is performed. It is preferable to press the body in the stacking direction to bond the sheets together.

  In addition, in the laminated body obtained by laminating | stacking a sheet | seat, it is guessed that a heat conductive filler etc. are arranged in the direction substantially orthogonal to the lamination direction.

And manufacture of the heat conductive sheet by the slice of a laminated body can be performed by slicing a laminated body at an angle of 45 degrees or less with respect to the lamination direction, and obtaining the heat conductive sheet which consists of a slice piece of a laminated body. . Here, the method for slicing the laminate is not particularly limited, and examples thereof include a multi-blade method, a laser processing method, a water jet method, and a knife processing method.
In addition, from the viewpoint of increasing the thermal conductivity of the heat conductive sheet, the angle at which the laminate is sliced is preferably 30 ° or less with respect to the stacking direction, and more preferably 15 ° or less with respect to the stacking direction. Preferably, it is approximately 0 ° with respect to the stacking direction (that is, the direction along the stacking direction).
From the viewpoint of easily slicing the laminate, the temperature of the laminate when slicing is preferably -20 ° C or higher and 30 ° C or lower. Furthermore, for the same reason, the laminated body to be sliced is preferably sliced while applying a pressure in a direction perpendicular to the lamination direction, and a pressure of 0.1 MPa to 0.5 MPa in the direction perpendicular to the lamination direction. It is more preferable to slice while loading.

EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to these Examples.
In Examples and Comparative Examples, the volume average particle diameter of the particulate material (expanded graphite), the Mooney viscosity of the second material, the adhesive strength of the first region and the second region, the thermal conductivity of the thermal conductive sheet, The positional deviation property and the shape maintenance property were measured and evaluated using the following methods, respectively. Moreover, in the Example and the comparative example, the area ratio of the 2nd area | region in the one main surface of a heat conductive sheet and the area ratio of the 2nd area | region in the other main surface of a heat conductive sheet were the same.

<Volume average particle diameter of particulate material>
1 g of the first region sheet was added to 6 g of methyl ethyl ketone, and stirred for 5 minutes with a stirrer. By visual inspection, it was confirmed that there was no sheet-like material in the methyl ethyl ketone solvent. The obtained suspension was used as a test solution.
The particle diameter of the particulate material (expanded graphite) contained in the suspension was measured using a laser diffraction / scattering type particle size distribution measuring device (Horiba Seisakusho, model “LA-960”). Then, a volume-based particle size distribution curve with the horizontal axis as the particle diameter and the vertical axis as the volume of the particulate material is obtained, and the particle diameter (mode diameter) at the maximum value is defined as the volume average particle diameter of the particulate material. Asked.
<Mooney viscosity>
A Mooney viscometer (manufactured by Shimadzu Corporation, product name “MOONEY VISCOMETER SMV-202”) was used, and Mooney viscosity (ML _{1 + 4} , 100 ° C.) at a temperature of 100 ° C. was measured according to JIS K6300.
<Adhesive strength>
Using a probe tack tester (trade name “TAC1000”, manufactured by Resuka Co., Ltd.), the adhesive strength of the first region sheet and the adhesive strength of the second region sheet were measured, and the respective values were determined as the first region adhesive force. Force and adhesive strength of the second region.
Specifically, each of the first region sheet and the second region sheet was used as a test piece. Then, a flat probe having a diameter of 5 mm was pressed for 10 seconds under the conditions of a temperature of 25 ° C. and a load of 0.5 N against the substantially center position of the obtained test piece. Thereafter, the force (N / mm) required for pulling the pressed probe away from the test piece was measured and used as the adhesive strength.
<Thermal conductivity>
About the heat conductive sheet, using a resin material thermal resistance tester (product name “C47108” manufactured by Hitachi Technology & Service Co., Ltd.), the thermal resistance when a relatively low pressure of 0.05 MPa was applied at a temperature of 50 ° C. The value (° C./W) was measured. The smaller the thermal resistance value, the more excellent the thermal conductivity of the heat conductive sheet, for example, it indicates that the heat dissipation characteristic is excellent when it is interposed between the heat generator and the heat radiator.
<Position displacement resistance>
The static friction force between the aluminum plate and the heat conductive sheet was measured to evaluate the displacement resistance.
Specifically, a heat conductive sheet (vertical: 10 mm, horizontal: 10 mm, thickness: 150 μm) was attached to a 200 g moving weight with a double-sided tape (product name “Nystack” manufactured by Nichiban Co., Ltd.). Next, the heat conductive sheet side was placed on a 20 mm long × 20 mm wide × 1 mm thick aluminum plate, and the moving weight was pulled at a speed of 100 mm / min. And the maximum tensile test force (N) at the time of starting was read, and it was set as the static frictional force between an aluminum plate and a heat conductive sheet. As the static frictional force is larger, the heat conductive sheet is less likely to be displaced in the in-plane direction, which indicates that the displacement resistance is excellent.
<Shape maintenance>
The heat conductive sheet whose weight was measured was placed on a PET (polyethylene terephthalate) film and stored at room temperature (25 ° C.) for 24 hours. And the weight of the heat conductive sheet after storage was measured, and the weight change rate (= {(weight before storage−weight after storage) / weight before storage} × 100%) was determined. And it evaluated according to the following references | standards. As the rate of change in weight is smaller, transfer to the PET film of the second region made of the second material does not occur, indicating that the shape maintainability is better.
○: Weight change rate is 0.1% by mass or less ×: Weight change rate is more than 0.1% by mass

Example 1
<Manufacture of first area sheet>
50 parts by mass of expanded graphite (trade name “EC-100”, volume average particle diameter: 190 μm) manufactured by Ito Graphite Industries Co., Ltd. as a thermally conductive filler, and a thermoplastic fluororesin that is liquid at room temperature as a resin 100 parts by mass (made by Daikin Industries, Ltd., trade name “DAIEL G-101”) is heated to 80 ° C. with a Hobart mixer (manufactured by Kodaira Manufacturing Co., Ltd., trade name “ACM-5LVT type”, capacity: 5 L). For 30 minutes. The composition obtained by mixing was put into a wonder crush mill (trade name “D3V-10” manufactured by Osaka Chemical Co., Ltd.) and crushed for 1 minute.
Next, 5 g of the crushed composition (first material) was sandwiched between 50 μm thick PET films (protective film) subjected to sandblast treatment, a roll gap of 550 μm, a roll temperature of 50 ° C., a roll linear pressure of 50 kg / cm, a roll Roll forming was performed at a speed of 1 m / min to obtain a first region sheet having a length of 50 mm, a width of 50 mm, and a thickness of 0.5 mm.
And the volume average particle diameter of the particulate material (expanded graphite) in the sheet | seat for 1st area | regions, and the adhesive force of the sheet | seat for 1st area | regions were measured. The results are shown in Table 1.
<Manufacture of second area sheet>
97 parts by mass of a thermoplastic fluororesin that is liquid at room temperature as an adhesive resin (trade name “DAIEL G-101” manufactured by Daikin Industries, Ltd.) and SGCNT as a fibrous carbon nanomaterial (BET specific surface area: 1050 m ² / g) A mixture of 3 parts by mass was stirred with a pressure kneader. The composition obtained by mixing was put into a wonder crush mill (trade name “D3V-10” manufactured by Osaka Chemical Co., Ltd.) and crushed for 1 minute. Then, the Mooney viscosity of the crushed composition (second material) was measured.
Subsequently, 5 g of the crushed composition (second material) is sandwiched between 50 μm thick PET films (protective film) subjected to sandblasting, a roll gap of 550 μm, a roll temperature of 50 ° C., a roll linear pressure of 50 kg / cm, a roll Roll forming was performed at a speed of 1 m / min to obtain a second region sheet (strip) having a length of 50 mm, a width of 2.5 mm, and a thickness of 0.5 mm.
Similarly, a second region sheet having a length of 50 mm, a width of 50 mm, and a thickness of 0.5 mm was prepared for measuring the adhesive strength. And the adhesive force of the sheet | seat for 2nd area | regions was measured. The results are shown in Table 1.
<Formation of laminate>
On the laminated structure (50 mm long, 50 mm wide, 5 mm high) formed by laminating 10 sheets for the first area, the sheet for the second area (strip) is arranged in the vertical direction of the sheet for the second area. A total of 10 sheets were arranged in parallel so as to coincide with the longitudinal direction of the one area sheet and so that the adjacent second area sheets were separated from each other by 2.5 mm. And 10 sheets of 1st area | region sheets were laminated | stacked on the sheet | seat for 2nd area | regions, and it pressed, and obtained the block body (laminated body) of height 10mm.
<Preparation of heat conductive sheet>
While pressing the resulting laminate with a pressure of 0.3 MPa, the slicer for woodworking (manufactured by Marunaka Steel Co., Ltd., trade name “Super Finished Plane Super Mecha S”) was used to reduce the stacking direction to 0. The sheet was sliced at an angle of 50 degrees (in other words, sliced in the normal direction of the main surface of the laminated sheets) to obtain a sheet of length 50 mm × width 10 mm × thickness 150 μm. Two single blades contact each other on the opposite side of the cutting blade, and the leading edge of the front edge is 0.5 mm higher than the leading edge of the back edge, and the protruding length from the slit portion is 0.11 mm A two-blade blade having a blade angle of 21 ° on the front blade was used.
Next, the obtained sheet is cut at a position of 10 mm in the length direction from the edge in the length direction of the sheet, and has a plan view shape as shown in FIG. A heat conductive sheet having a thickness of 150 μm was obtained.
Various evaluations were performed. The results are shown in Table 1. Incidentally, the total area of the second region in the main surface of the thermally conductive sheet ^was 2.5mm 2 (= 2.5mm × 0.5mm × 2 points).

(Example 2)
At the time of forming the laminate, the second region sheet (strip) is placed on the laminated structure (50 mm long, 50 mm wide, 2.5 mm high) formed by laminating five sheets for the first region. The distance from the lateral edge of the laminated structure to the lateral center position of the second region sheet is 1.25 mm so as to match the longitudinal direction of the region sheet and the longitudinal direction of the first region sheet, After arranging 10 pieces in parallel to be 8.75 mm, 11.25 mm, 18.75 mm, 21.25 mm, 28.75 mm, 31.25 mm, 38.75 mm, 41.25 mm, 48.75 mm, the first region 10 sheets for sheets were further laminated, 10 sheets for the second area (strips) were arranged in parallel on the same, and 5 sheets for the first area were further laminated thereon. As in Example 1, the first area DOO manufacture, production of the second region sheet were produced in the formation and heat conducting sheet of the stack. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (b). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In addition, the total area of the 2nd area | region in the main surface of a heat conductive sheet was 5 mm < ² > (= 2.5 mm x 0.5 mm x 4 places).

(Example 3)
A laminated structure in which only a second area sheet having a length of 50 mm, a width of 50 mm, and a thickness of 0.5 mm is produced when the second area sheet is produced, and four first area sheets are laminated when a laminate is formed. After laminating one sheet for the second region on the top (50 mm in length, 50 mm in width, 2.0 mm in height), 10 sheets for the first region, 1 sheet for the second region, Except for sequentially laminating four sheets for one region, the production of the first region sheet, the production of the second region sheet, the formation of the laminate and the production of the heat conductive sheet were carried out in the same manner as in Example 1. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (c). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. Incidentally, the total area of the second region in the main surface of the thermally conductive sheet ^was 10mm 2 (= 10mm × 0.5mm × 2 points).

Example 4
A laminated structure in which a second area sheet having a length of 50 mm, a width of 50 mm, and a thickness of 0.25 mm is produced at the time of producing the second area sheet, and three sheets for the first area are laminated at the time of forming a laminate. After laminating one sheet for the second region having a thickness of 0.25 mm on the top (50 mm in length, 50 mm in width, and 1.5 mm in height), four sheets for the first region and a thickness of 0 were formed thereon. 1 sheet for the second area of 25 mm, 4 sheets for the first area, 1 sheet for the second area of 0.25 mm, 4 sheets of the first area, 2nd area of the thickness of 0.25 mm Except that one sheet for the first region and three sheets for the first region were sequentially laminated, the production of the sheet for the first region, the production of the sheet for the second region, the formation of the laminate, and the heat conductive sheet Was made. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (d). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In addition, the total area of the 2nd area | region in the main surface of a heat conductive sheet was 10 mm < ² > (= 10 mm x 0.25 mm x 4 places).

(Example 5)
At the time of manufacturing the sheet for the second region, the amount of thermoplastic fluororesin (trade name “DAIEL G-101”, manufactured by Daikin Industries, Ltd.) that is liquid at room temperature was changed to 99 parts by mass, and SGCNT (BET specific surface area: 1050 m). ² / g) is changed to 1 part by mass, and a second region sheet (strip) having a length of 50 mm, a width of 2.5 mm, and a thickness of 0.25 mm is manufactured. On the laminated structure (50 mm long, 50 mm wide, 0.5 mm in height) formed by laminating one area sheet, the second area sheet (strip) is arranged in the vertical direction of the second area sheet. The distances from the lateral edge of the laminated structure to the lateral center position of the second region sheet are 1.25 mm, 8.75 mm, 11.25 mm, respectively, so as to coincide with the longitudinal direction of the one region sheet, 18.75mm, 21.25mm, 28 After arranging a total of 10 sheets so as to be 75 mm, 31.25 mm, 38.75 mm, 41.25 mm, and 48.75 mm, one sheet for the first area is further laminated, and then the sheet for the second area (Strip) from the lateral edge of the laminated structure to the lateral center position of the second region sheet so as to coincide with the longitudinal direction of the second region sheet and the longitudinal direction of the first region sheet A total of 10 sheets so that the distance of each becomes 3.75 mm, 6.25 mm, 13.75 mm, 16.25 mm, 23.75 mm, 26.25 mm, 33.75 mm, 36.25 mm, 43.75 mm, 46.25 mm In the same manner as in Example 1 except that the operation of laminating one sheet for the first region was repeated four times, the production of the first region sheet, the production of the second region sheet, the laminate Formation and And a heat conductive sheet were prepared. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (e). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In addition, the total area of the 2nd area | region in the main surface of a heat conductive sheet was 10 mm < ² > (= 2.5 mm x 0.25 mm x 16 places).

(Example 6)
At the time of manufacturing the sheet for the second region, the amount of thermoplastic fluororesin (trade name “DAIEL G-101”, manufactured by Daikin Industries, Ltd.) that is liquid at room temperature was changed to 93 parts by mass, and SGCNT (BET specific surface area: 1050 m). The production of the first region sheet, the production of the second region sheet, the formation of the laminate and the production of the heat conduction sheet were carried out in the same manner as in Example 5 except that the amount of ² / g) was changed to 7 parts by mass. went. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (e). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In addition, the total area of the 2nd area | region in the main surface of a heat conductive sheet was 10 mm < ² > (= 2.5 mm x 0.25 mm x 16 places).

(Example 7)
At the time of manufacturing the sheet for the second region, the amount of thermoplastic fluororesin (trade name “DAIEL G-101”, manufactured by Daikin Industries, Ltd.) that is liquid at room temperature was changed to 90 parts by mass, and SGCNT (BET specific surface area: 1050 m). ² / g) in the same manner as in Example 5 except that 10 parts by mass of expanded graphite (trade name “EC-100”, volume average particle diameter: 190 μm, manufactured by Ito Graphite Industries Co., Ltd.) was used. Manufacture of the sheet | seat for one area | region, manufacture of the sheet | seat for 2nd area | regions, formation of the laminated body, and preparation of the heat conductive sheet were performed. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (e). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In addition, the total area of the 2nd area | region in the main surface of a heat conductive sheet was 10 mm < ² > (= 2.5 mm x 0.25 mm x 16 places).

(Example 8)
At the time of manufacturing the sheet for the second region, instead of the crushed composition, as a second material, a solid thermoplastic fluororesin under normal temperature and normal pressure (manufactured by 3M Japan, trade name “Dyneon (registered trademark) E-20575”, Laminated structure using only Mooney viscosity (ML _{1 + 4} , 100 ° C.): 4.0) and laminating 10 sheets for the first region at the time of forming the laminate (length 50 mm, width 50 mm, height 5 mm) The second region sheet (strip) is secondly aligned with the longitudinal direction of the second region sheet and the longitudinal direction of the first region sheet and from the lateral edge of the laminated structure. The distance to the lateral center position of the area sheet is 3.75 mm, 6.25 mm, 13.75 mm, 16.25 mm, 23.75 mm, 26.25 mm, 33.75 mm, 36.25 mm, 43.75 mm, 4 .Since a total of 10 sheets were arranged in parallel so as to be 25 mm, the production of the first area sheet and the production of the second area sheet were performed in the same manner as in Example 1 except that 10 sheets of the first area sheet were further laminated. Then, a laminate was formed and a heat conductive sheet was produced. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (f). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. Incidentally, the total area of the second region in the main surface of the thermally conductive sheet ^was 2.5mm 2 (= 2.5mm × 0.5mm × 2 points).

Example 9
At the time of manufacturing the sheet for the second region, instead of the crushed composition, as a second material, a solid thermoplastic fluororesin under normal temperature and normal pressure (manufactured by 3M Japan, trade name “Dyneon (registered trademark) E-20575”, Production of first area sheet, production of second area sheet, formation of laminate and heat in the same manner as in Example 2 except that only Mooney viscosity (ML _{1 + 4} , 100 ° C.): 4.0) was used. A conductive sheet was prepared. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (b). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In addition, the total area of the 2nd area | region in the main surface of a heat conductive sheet was 5 mm < ² > (= 2.5 mm x 0.5 mm x 4 places).

(Comparative Example 1)
A laminated structure in which only the second area sheet having a length of 50 mm, a width of 50 mm, and a thickness of 0.5 mm is produced when the second area sheet is produced, and two sheets of the first area sheet are laminated at the time of forming the laminate. After laminating one sheet for the second region on the top (50 mm in length, 50 mm in width, 1.0 mm in height), four sheets for the first region, one sheet for the second region, Example 1 except that 4 sheets for one area, 1 sheet for 2nd area, 4 sheets for 1st area, 1 sheet for 2nd area, 2 sheets for 1st area were laminated in order. The manufacture of the first region sheet, the manufacture of the second region sheet, the formation of the laminate, and the production of the heat conductive sheet were performed. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (d). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. In addition, the total area of the 2nd area | region in the main surface of a heat conductive sheet was 20 mm < ² > (= 10 mm x 0.5 mm x 4 places).

(Comparative Example 2)
Without producing the second region sheet, at the time of forming the laminate, the production of the first region sheet was the same as in Example 1, except that only the first region sheet was laminated to form a laminate. Formation of a laminated body and preparation of a heat conductive sheet were performed. Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
At the time of manufacturing the sheet for the second region, the amount of the thermoplastic fluororesin (trade name “DAIEL G-101”, manufactured by Daikin Industries, Ltd.) that is liquid at room temperature was changed to 99.5 parts by mass, and SGCNT (BET specific surface area) : The production of the first region sheet, the production of the second region sheet, the formation of the laminate and the heat conduction in the same manner as in Example 3 except that the amount of 1050 m ² / g) was changed to 0.5 parts by mass. A sheet was prepared. In addition, the planar view shape of the heat conductive sheet was a shape as shown in FIG.5 (c). Measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 1. Incidentally, the total area of the second region in the main surface of the thermally conductive sheet ^was 10mm 2 (= 10mm × 0.5mm × 2 points).

  From Table 1, it can be seen that the heat conductive sheets of Examples 1 to 9 have sufficiently high heat conductivity and are less likely to cause positional displacement in the in-plane direction. On the other hand, from Table 1, in the heat conductive sheet of Comparative Example 1 in which the area ratio occupied by the second region is large, the thermal conductivity decreases, and in the heat conductive sheet of Comparative Example 2 that does not have the second region, the position in the in-plane direction. It can be seen that the heat transfer sheet of Comparative Example 3 in which the deviation cannot be suppressed and the Mooney viscosity of the second material is less than 2 cannot maintain the shape.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the heat conductive sheet which has high heat conductivity and does not raise | generate the position shift of an in-plane direction easily.

DESCRIPTION OF SYMBOLS 10 Thermal conductive sheet 11 1st area | region 12 2nd area | region 20 Laminated body 21 Sheet | seat 22A, 22B for 1st areas 2nd area | region sheets

Claims (8)

A first region comprising a first material comprising a resin and a thermally conductive filler;
A second region having a Mooney viscosity (ML _{1 + 4} , 100 ° C.) of 2 or more and an adhesive strength of 5.0 N / mm or more;
Have
The heat conductive sheet whose area ratio which said 2nd area | region occupies in at least one main surface is more than 0% and less than 20%.   The heat conductive sheet according to claim 1, wherein the area ratio occupied by the second region is 1% or more and 15% or less.   The heat conductive sheet according to claim 1 or 2, wherein the resin comprises at least one of a fluororesin and a silicon resin.   The heat conductive sheet according to any one of claims 1 to 3, wherein the second material includes an adhesive resin and a heat conductive filler.   The heat conductive sheet of Claim 4 whose content rate of the said heat conductive filler in said 2nd material is 1.0 mass% or more and 20.0 mass% or less. The thermally conductive filler in the second material comprises fibrous carbon nanomaterial;
The BET specific surface area of the fibrous carbon nanomaterials or less 400 meters ² / g or more 2500 m ² / g, the heat conducting sheet according to claim 4 or 5.   The heat conductive sheet in any one of Claims 1-6 in which the said heat conductive filler in said 1st material contains a particulate material with a volume average particle diameter of 150 micrometers or more and 300 micrometers or less.   The heat conductive sheet of Claim 7 whose content rate of the said particulate material in said 1st material is 5 volume% or more and 30 volume% or less.

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