Heat dissipation molded body, method for manufacturing heat dissipation molded body, and method for arranging heat dissipation molded body

Abstract

This heat dissipation molded body comprises: a top surface part having a flat surface; a wall surface part provided on an outer peripheral portion of the top surface part; and a recess formed by the top surface part and the wall surface part. The top surface part has an outer surface, which is a surface opposite to the recess, and an inner surface, which is a surface on the recess side. A tack value T1 of the outer surface is smaller than a tack value T2 of the inner surface.

Description

Heat dissipation molded body, method for manufacturing a heat dissipation molded body, method for arranging a heat dissipation molded body

[0001] The present invention relates to a heat-dissipating molded body, and to a method for manufacturing and arranging a heat-dissipating molded body.

[0002] In electronic devices such as computers, automotive parts, and mobile phones, heat sinks and other heat dissipators are commonly used to dissipate heat generated from heat-generating elements such as semiconductor components and mechanical parts. To improve the heat transfer efficiency to the heat sink, it is known that thermally conductive materials such as thermally conductive sheets or grease are placed between the heat-generating element and the heat sink.

[0003] Development of thermally conductive materials has also focused on their peelability or surface tackiness. For example, Patent Document 1 discloses an invention relating to a heat dissipation material obtained by filling and curing between an electromagnetic wave shielding case and an electronic component, and it is stated that the 180-degree peel strength of the heat dissipation material to a SUS substrate is below a certain level, indicating excellent peelability.

[0004] Patent Document 2 discloses an invention relating to a thermal conductive sheet comprising a resin and particulate carbon material, wherein the thermal resistance value under a pressure of 0.05 MPa is below a certain level, and the tack measured in a probe tack test is within a certain range, and it is stated that the tackiness of the thermal conductive sheet can be adjusted by the proportion of particulate carbon material. Patent Document 3 discloses an invention relating to a method for manufacturing a non-adhesive thermal conductive silicone rubber sheet, which includes a step of irradiating a thermal conductive silicone rubber sheet with an electron beam to promote the hardening of the surface of the thermal conductive silicone rubber sheet. Patent Document 3 states that the tackiness of the surface of the non-adhesive thermal conductive silicone rubber sheet can be adjusted more easily and stably by keeping the electron beam irradiation dose within a certain range.

[0005] Patent No. 6268086 Patent No. 6930523 Patent No. 7208860

[0006] Incidentally, while some heat sinks and heating elements have flat surfaces, many have partially stepped or uneven shapes due to the increasing complexity of device structures in recent years. Therefore, thermal conductive materials are required to be molded into three-dimensional shapes that can conform to the complex shapes of heat sinks and heating elements. Furthermore, hardening thermal conductive materials into three-dimensional shapes using compression molding machines is also being considered. Such thermal conductive materials have the advantage of minimizing material waste and being usable precisely at heat dissipation points. In recent years, there has been a demand for automation in the manufacturing processes of machine parts and the like, and the process of picking up thermal conductive materials with devices such as suction pads and placing the picked-up thermal conductive materials at heat dissipation points (pick and place) is also being considered.

[0007] However, conventional molded bodies using thermally conductive materials have problems such as the inability to install the molded body because it does not move away from the device used to install it, or the molded body being misaligned even if it is installed.

[0008] Therefore, the object of the present invention is to provide a heat-dissipating molded body that is easy to handle and, for example, can be picked and placed using an automated process.

[0009] In view of the above, the inventors have found that the above problems can be solved by introducing a tack difference between the inner and outer surfaces of the heat-dissipating molded body, and adjusting it so that the tack value of the outer surface is smaller than the tack value of the inner surface. The present invention provides the following [1] to

[14] .

[0010] [1] A heat dissipation molded body comprising a top surface having a flat surface, a wall surface provided on the outer periphery of the top surface, and a recess formed by the top surface and the wall surface, wherein the top surface has an outer surface which is the surface opposite to the recess and an inner surface which is the surface on the recess side, and the tack value T1 of the outer surface is smaller than the tack value T2 of the inner surface. [2] The heat dissipation molded body according to [1], wherein the tack value T1' of the outer surface of the wall surface is smaller than the tack value T2' of the inner surface of the wall surface. [3] The heat dissipation molded body according to [1] or [2], comprising a polymer matrix and a thermally conductive filler. [4] The heat dissipation molded body according to any one of [1] to [3], wherein the shape of the heat dissipation molded body is a cap shape. [5] The heat dissipation molded body according to any one of [1] to [4], wherein at least a part of the heat dissipation molded body is in contact with a heat-generating conductive member of an electronic component device, and is used to dissipate heat generated from the heat-generating conductive member. [6] The tack value T1 of the outer surface is 40 mN / mm ２ The following conditions apply, and the tack value T2 of the inner surface is 60 mN / mm ２The heat-dissipating molded body according to any one of [1] to [5] above. [7] A method for manufacturing a heat-dissipating molded body, comprising the steps of: pouring a thermally conductive composition into a compression mold; heating and curing the thermally conductive composition; and demolding the cured product of the thermally conductive composition from the compression mold to obtain a heat-dissipating molded body, wherein the heat-dissipating molded body comprises: a top surface having a flat surface; a wall surface provided on the outer periphery of the top surface; and a recess formed by the top surface and the wall surface, wherein the top surface has an outer surface which is the surface opposite to the recess and an inner surface which is the surface on the recess side, and the tack value T1 of the outer surface is smaller than the tack value T2 of the inner surface. [8] The method for manufacturing a heat-dissipating molded body according to [7], wherein in the step of pouring the thermally conductive composition, a reactive resin is applied to at least a part of the inner surface of the compression mold. [9] A method for manufacturing a heat-dissipating molded article according to [8], wherein the reactive resin is applied by spray coating.

[10] A method for manufacturing a heat-dissipating molded article according to [8] or [9], wherein the viscosity of the reactive resin at room temperature is 50,000 mPa·s or less.

[11] A method for manufacturing a heat-dissipating molded article according to any one of [8] to

[10] , wherein the amount of reactive resin applied is 0.37 mg / cm² or more.

[12] A method for arranging a heat-dissipating molded article, wherein the heat-dissipating molded article comprises a top surface having a flat surface, a wall surface provided on the outer periphery of the top surface, and a recess formed by the top surface and the wall surface, wherein the top surface has an outer surface which is the surface opposite to the recess and an inner surface which is the surface on the recess side, and the heat-dissipating molded article is arranged on the adherend by lifting the flat surface by suction with a suction device, moving the suction device so that the inner surface is in contact with the adherend, and stopping the suction of the suction device.

[13] The tack value T1 of the outer surface is 20 mN / mm ２ More than 67mN / mm ２The method for arranging a heat dissipation molded body according to

[12] , wherein the contact area between the heat dissipation molded body and the suction device is Y, and the tack value T1 is X, such that X and Y satisfy the relationship shown in the following formula (1): 0 < Y < -1.8X + 100 Formula (1)

[14] The method for arranging a heat dissipation molded body according to

[12] or

[13] , wherein the suction device has an adsorption pad, and the material of the adsorption pad is silicone rubber.

[0011] According to the present invention, it is possible to provide a heat-dissipating molded body that is easy to handle and, for example, can be picked and placed using an automated process.

[0012] This is a schematic perspective view showing one embodiment of a heat-dissipating molded body. This is a schematic cross-sectional view showing one embodiment of a heat-dissipating molded body. This is a schematic perspective view showing one embodiment of a heat-dissipating molded body. This is a schematic perspective view showing one embodiment of a heat-dissipating molded body. This is a schematic cross-sectional view showing one embodiment of a heat-dissipating molded body. This is a schematic cross-sectional view showing one process of arranging a heat-dissipating molded body.

[0013] [Heat Dissipation Molded Body] As shown in Figures 1 and 2, the heat dissipation molded body 10 comprises a top surface portion 11, a wall portion 12 provided on the outer periphery of the top surface portion 11, and a recess 14 formed by the top surface portion 11 and the wall portion 12. The wall portion 12 is formed to surround the recess 14 around its entire circumference. The top surface portion 11 is connected to the tip of the wall portion 12, and the inner surface 11B of the top surface portion 11 becomes the bottom surface of the recess 14. The top surface portion 11 also has an outer surface 11A, which is the side opposite to the recess 14, and an inner surface 11B, which is the side facing the recess 14, and the tack value T1 of the outer surface 11A is smaller than the tack value T2 of the inner surface 11B.

[0014] The heat dissipation molded body 10 of the present invention, having the above configuration, enables pick-and-place in an automated process, contributing to improved production efficiency and reduced defect rates for devices such as electronic equipment. In the present invention, since the tack value T1 is smaller than the tack value T2, the heat dissipation molded body 10 can be freed from the suction device described later, and the heat dissipation molded body 10 can be positioned without displacement. Furthermore, since the inner surface 11B has a certain tackiness, the heat dissipation molded body 10 can adhere to a substrate, such as a housing described later, and the heat dissipation molded body can be positioned without displacement. In addition, when reworking, the electronic equipment can be disassembled with the inner surface 11B attached to the substrate, preventing the heat dissipation molded body 10 from unintentionally adhering to other parts that come into contact with it, thereby improving the workability of the rework process. Furthermore, after the inner surface 11B of the heat dissipation molded body 10 is attached to the substrate, displacement of the heat dissipation molded body 10 can be prevented when pressing it to other members other than the substrate, or when rotating the orientation during product assembly.

[0015] The shape of the heat-dissipating molded body 10 is not particularly limited, as long as it includes a top surface portion 11, a wall surface portion 12, and a recess 14. For example, as in this embodiment, the cross-section of the wall surface portion 12 may be rectangular, or it may have a shape other than rectangular, as will be described later. Furthermore, the heat-dissipating molded body 10 is often configured in a cap shape by the top surface portion 11 and the wall surface portion 12, and this cap shape makes it easier to perform pick-and-place in an automated process.

[0016] The heat dissipation molded body 10 has at least the outer surface 11A being a flat surface. Since the outer surface 11A is a flat surface, it becomes easier to adsorb the heat dissipation molded body 10 with a suction device described later. Also, it is preferable that the inner surface 11B of the top surface portion 11 of the heat dissipation molded body 10 is also a flat surface. Since the inner surface 11B is a flat surface, it becomes easier to adhere to an adherend or the like. Further, by the heat dissipation molded body 10 having the wall surface portion 12, the creepage distance between the member (adherend) disposed inside the recess 14 and the member disposed on the outer surface 11A of the top surface portion 11 can be increased, and the insulation between these members can be ensured. Furthermore, by disposing an adherend inside the recess 14, the space for disposing the heat dissipation molded body 10 can be minimized, so it can also be used for a space-saving device. In addition, it becomes easier to increase the contact area between the member (adherend) disposed inside the recess 14 and the heat dissipation molded body 10, and it becomes easier to improve the heat dissipation performance.

[0017] The difference between the tack value T1 and the tack value T2 in the heat dissipation molded body 10 is 5 mN / mm ２ or more, preferably ２ 10 mN / mm or more, ２ more preferably 20 mN / mm or more, and even more preferably 20 mN / mm or more. By making the difference between the tack value T1 and the tack value T2 a certain value or more, the handling property of the heat dissipation molded body 10 is likely to be good, and it becomes easier to perform pick and place by an automated process. The difference between the tack value T1 and the tack value T2 is, from the viewpoint of adjusting the tack value T2 to an appropriate range to make the handling property during the attachment of the heat dissipation molded body 10 good, for example, 100 mN / mm ２ or less, preferably 70 mN / mm ２ or less, and more preferably 50 mN / mm ２ or less.

[0018] The tack value T1 is, for example, 67 mN / mm ２ or less, preferably ２ 40 mN / mm or less, more preferably ２ 30 mN / mm or less, and even more preferably 25 mN / mm ２More preferably, the following conditions are met. When the tack value T1 is below the above upper limit value, it becomes easier to release the heat dissipation molded body 10 from the suction device described later, and it becomes easier to place the heat dissipation molded body 10 without displacement. From the perspective of workability, the lower the tack value T1, the better. It may be 0 mN / mm ２ or more. However, from the perspective of improving the followability to the heat-generating conductive member and the like described later, for example, it is 1 mN / mm ２ or more, preferably 5 mN / mm ２ or more, more preferably 10 mN / mm ２ or more, still more preferably 15 mN / mm ２ or more.

[0019] The tack value T2 is preferably 60 mN / mm ２ or more, more preferably 70 mN / mm ２ or more, and still more preferably 90 mN / mm ２ or more. When the tack value T2 is above the above lower limit value, it becomes easier to attach the heat dissipation molded body 10 to the adherend, and the workability of the rework process described above is also likely to be improved. The tack value T2 is not particularly limited, but practically, for example, it is 1000 mN / mm ２ or less, preferably 200 mN / mm ２ or less.

[0020] From the perspective of making it easier to attach the heat dissipation molded body 10 to the adherend and easier to release it from the suction device described later, the tack value T1 on the outer surface is 40 mN / mm ２ or less, and the tack value T2 on the inner surface is 60 mN / mm ２ or more, which is preferable. The tack values T1 and T2 can be measured by the method described in the examples. The same applies to the tack values T1' and T2' described later.

[0021] The wall portion 12 constituting the heat dissipation molded body 10 of the present invention preferably has an outer surface which is the side opposite to the recess 14 and an inner surface which is the side facing the recess 14. In this case, it is preferable that the tack value T1' of the outer surface of the wall portion 12 is smaller than the tack value T2' of the inner surface of the wall portion 12. By making the tack value T1' smaller than the tack value T2', it is possible to prevent the heat dissipation molded body 10 from unintentionally adhering to members other than the adherend when attaching it to the adherend, resulting in improved handling. Also, if the suction device adheres not only to the top portion 11 but also to the wall portion 12, the wall portion 12 becomes easier to release from the suction device. On the other hand, by increasing the tack value T2', misalignment of the heat dissipation molded body 10 after it has been attached to the adherend becomes less likely. The preferred ranges for tack value T1', tack value T2', and the difference between them are the same as those for tack value T1, tack value T2, and the difference between tack value T1 and tack value T2 described above, so a detailed explanation is omitted.

[0022] The tack values ​​T1 and T1' can be lowered by forming a skin layer with low tackiness on the outer surface of the top surface and the outer surface of the wall surface using a reactive resin, for example, as described later. The tack values ​​T2 and T2' can be adjusted to a certain level or higher by using a polymer matrix, for example, as described later. For example, using rubber in the polymer matrix makes it easier to adjust the tack values ​​T2 and T2' to a certain level or higher. Also, when using a curable component, it is easier to raise the tack values ​​T2 and T2' by increasing the mixing ratio of the main agent to the curing agent. Specifically, when the matrix is ​​silicone rubber and both alkenyl group-containing organopolysiloxane and hydrosilyl group-containing organopolysiloxane are used, it is easier to raise the tack values ​​T2 and T2' by reducing the ratio of hydrosilyl groups to alkenyl groups in the curable component.

[0023] More specifically, the shape of the heat dissipation molded body 10 can be described as follows: The wall portion 12 of the heat dissipation molded body 10 shown in Figure 1 comprises first and second side wall portions 13A and 13B facing each other, and third and fourth side wall portions 13C and 13D facing each other, and these side wall portions 13A to 13D are connected to form the wall portion 12. As a result, the wall portion 12 has a rectangular cross-section, and the top portion 11 has a rectangular shape. In addition, adjacent side wall portions (for example, side wall portion 13A and side wall portion 13C) of the wall portion 12 are connected via curved corners, but the corners do not necessarily have to be curved. Furthermore, the recess 14 is preferably tapered toward the top portion 11, and therefore, it is preferable that the opposing inner surfaces of the wall portion 12 (the inner surfaces of side wall portions 13A and 13B, and the inner surfaces of side wall portions 13C and 13D) are inclined in the height direction so that they are closer together. Because the recess 14 is tapered, the end of the wall portion 12 widens outward, making it easier to insert the object to be attached into the recess 14. However, the recess 14 does not necessarily have to be tapered; in that case, the opposing inner surfaces of the wall portion 12 (the inner surfaces of side wall portions 13A and 13B, and the inner surfaces of side wall portions 13C and 13D) may be parallel to each other.

[0024] The length L3 at the longest point of the outer surface 11A of the top surface 11 is not particularly limited, but is, for example, 5 mm or more and 150 mm or less, preferably 10 mm or more and 100 mm or less. Length L3 is, for example, the diameter if the shape of the outer surface 11A is a circle, the length of the major axis if it is an ellipse, and usually the length of the diagonal if it is a quadrilateral. The thickness D1 of the top surface 11 is not particularly limited, but is, for example, 0.5 mm or more and 5 mm or less, preferably 1 mm or more and 3 mm or less. The thickness D2 of the wall surface 12 is not particularly limited, but is, for example, 0.5 mm or more and 3 mm or less, preferably 0.7 mm or more and 2 mm or less. The length L1 of the wall surface 12 is not particularly limited, but is, for example, 2 mm or more and 50 mm or less, preferably 3 mm or more and 30 mm or less. Length L1 is the shortest distance from the inner surface 11B of the top surface 11 to the end of the wall surface 12.

[0025] Furthermore, although the wall portion 12 of the heat dissipation molded body 10 had a rectangular cross-section, it may have a shape other than a rectangular shape, a polygon other than a rectangular shape, a circular shape as shown in Figure 3, an elliptical shape, a deformed circular or elliptical shape, or any other shape.

[0026] Furthermore, although Figures 1 to 3 show the heat dissipation molded body 10 having a single cap shape including a top surface portion 11, a wall surface portion 12, and a recess 14, as shown in Figure 4, the heat dissipation molded body 10 may have multiple cap shapes. In this case, adjacent cap shapes may be connected to each other via a connecting portion 15. The connecting portion 15 may be configured to connect the wall surfaces 12 to each other. The inside of the connecting portion 15 may be hollow, and the recesses inside each cap may be connected via this hollow space. That is, the hollow space inside the connecting portion may be connected to the recesses inside each cap without going through the wall surface portion. By having multiple cap shapes, the heat dissipation molded body 10 can accommodate multiple adherends inserted into the recesses. When there are multiple cap shapes, the number of cap shapes is not particularly limited and may be two, three or more. Furthermore, even when the heat dissipation molded body 10 has multiple cap shapes, the cross-sectional shape of the wall portion 12 constituting each cap shape is not limited to a circle as shown in Figure 4, as in the case where there is only one cap shape, but may also be square or have a shape other than a circle or square.

[0027] As shown in Figures 5 and 6, the heat-dissipating molded body 10 of the present invention may have a flange portion 26 at the end of the wall portion 12 that protrudes outward from the outer circumferential surface of the wall portion 12. Here, the flange portion 26 should protrude outward along the entire circumference of the wall portion 12. The length L4 of the flange portion 26 may be, for example, 0.5 mm or more and 30 mm or less, but 1 mm or more and 15 mm or less is preferable. Having a flange portion can improve dielectric breakdown performance. The length L4 of the flange portion is the shortest distance from the inner circumferential surface at the end of the wall portion 12 to the tip of the flange portion 26. The thickness D3 of the flange portion 26 is not particularly limited, but for example, 0.2 mm or more and 15 mm or less, preferably 0.3 mm or more and 8 mm or less. However, the flange portion 26 does not necessarily have to protrude outward from the end of the wall portion 12, and may protrude outward from any position on the outer circumferential surface of the wall portion 12.

[0028] Even when the heat dissipation molded body 10 is provided with a flange portion 26, the cross-sectional shape of the wall portion 12 does not have to be a rectangle; it may be circular, elliptical, or any other shape. Also, even when the flange portion 26 is provided, two or more cap shapes may be provided on a single heat dissipation molded body. In that case, it is preferable that adjacent cap shapes be connected to each other. In this case, the wall portions 12 may be connected to each other by a connecting portion 15, or the flange portions 26 may be connected to each other.

[0029] <Heat Dissipating Molded Body> Next, the heat dissipating molded body used in the present invention will be described in more detail. The heat dissipating molded body of the present invention is preferably a cured product of a thermally conductive resin composition, as will be described later. Furthermore, the heat dissipating molded body preferably contains a polymer matrix and a thermally conductive filler. The polymer matrix and the thermally conductive filler will be described in detail below.

[0030] <Polymer Matrix> The polymer matrix is ​​a polymer compound such as an elastomer or rubber, and preferably a liquid curable component consisting of a mixed system such as a main agent and a curing agent is cured to form the matrix. The curable component may consist of, for example, uncrosslinked rubber and a crosslinking agent, or it may contain monomers, prepolymers, etc., and a curing agent. The curing reaction may be room temperature curing or thermocuring. Examples of polymer matrices include acrylic rubber, nitrile rubber, isoprene rubber, urethane rubber, ethylene propylene rubber, styrene-butadiene rubber, butadiene rubber, fluororubber, and butyl rubber. Among these, urethane rubber and silicone rubber are preferred from the viewpoint of ease of casting and the ability to impart tackiness, and among these, silicone rubber is more preferred from the viewpoint of easily imparting tackiness to the heat-dissipating molded body, as well as from the viewpoint of insulation and heat dissipation. The polymer matrix is ​​also made of a resin component, and it is preferable that it is a cured product of a resin component containing a curable component. The polymer matrix may be used alone or two or more types may be used in combination.

[0031] In heat-dissipating molded articles, when the polymer matrix is ​​urethane rubber, examples include those in which a urethane prepolymer is cured with a curing agent such as an amine-based curing agent, those in which polyisocyanate and a polyol compound are mixed and cured, and those in which polyisocyanate, a polyol compound, and a chain extender are mixed and cured.

[0032] In a heat-dissipating molded article, if the polymer matrix is ​​silicone rubber, the silicone rubber is preferably a cured product of organopolysiloxane, and is preferably formed from a resin component containing organopolysiloxane.

[0033] The polymer matrix is ​​more preferably a cured product of an addition-reaction type organopolysiloxane. The addition-reaction type organopolysiloxane may contain an alkenyl group-containing organopolysiloxane and a hydrosilyl group-containing organopolysiloxane. Furthermore, the heat-dissipating molded article may appropriately contain a heat-conductive filler, resin components other than the curable component, and components other than the resin component (such as additives), as described in the section on heat-conductive compositions later.

[0034] Alkenyl group-containing organopolysiloxanes are organopolysiloxanes that have alkenyl groups, and the alkenyl groups may be present in the side chains, at the terminal, or both the side chains and the terminal. Alkenyl group-containing organopolysiloxanes may be used alone or in combination of two or more. When using organopolysiloxanes with alkenyl groups in the side chains (side-chain alkenyl group-containing organopolysiloxanes), it becomes easier to increase the gel fraction even when the ratio of hydrosilyl groups (H / Vi) in the resin component to alkenyl groups in the resin component is the same.

[0035] Using organopolysiloxanes containing side-chain alkenyl groups allows for a more uniform dispersion of crosslinking points in the resulting polymer matrix. This results in a relatively larger molecular weight at the crosslinking points, suppressing localized hardness increases and providing flexibility at the crosslinking points that was difficult to achieve with conventional structures. The organopolysiloxanes containing side-chain alkenyl groups may be linear, branched, or a mixture of linear and branched structures, but linear is preferred. The alkenyl groups contained in the side chains are present in locations other than the ends of the molecular chains in the polysiloxane structure. Furthermore, the organopolysiloxanes containing side-chain alkenyl groups may have alkenyl groups at the ends in addition to the side chains, but it is preferable that the alkenyl groups are present only in the side chains.

[0036] The organopolysiloxane containing side-chain alkenyl groups is preferably liquid at 25°C. The viscosity of the organopolysiloxane containing side-chain alkenyl groups at 25°C is preferably 50,000 mPa·s or less, more preferably 10,000 mPa·s or less, and even more preferably 3,000 mPa·s or less. By keeping the viscosity of the organopolysiloxane containing side-chain alkenyl groups below the upper limit, it is possible to prevent a decrease in reactivity or the thermally conductive composition from becoming highly viscous. Furthermore, the viscosity of the organopolysiloxane containing side-chain alkenyl groups at 25°C is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, and even more preferably 200 mPa·s or more. By keeping the viscosity of the organopolysiloxane containing side-chain alkenyl groups above the lower limit, it is possible to prevent the crosslinking density from becoming high and to lower the hardness after curing. Furthermore, this prevents the reaction from becoming too rapid, making it easier to ensure that the addition reaction proceeds appropriately. The viscosity is measured using a Brookfield B-type viscometer in accordance with JIS K7117-1. The spindle of the Brookfield B-type viscometer should be appropriately selected so that the torque is between 10% and 80%.

[0037] Alkenyl group-containing organopolysiloxanes may have one or more alkenyl groups, but it is preferable that they have two or more alkenyl groups. As described later, if the weight-average molecular weight (g / mol) is Mw and the alkenyl group concentration (μmol / g) is C, then the average number of alkenyl groups per molecule is Mw × C × 10 －６ It can be calculated using the following formula. The average number of alkenyl groups calculated in this way is preferably 2 or more, more preferably 2.2 or more, and even more preferably 2.4 or more. By setting the average number of alkenyl groups to 2 or more, a cross-linking structure can be appropriately introduced, making it easier to lower the compression set while maintaining good hardness, thermal conductivity, etc. Furthermore, the average number of alkenyl groups may be, for example, 5 or less, but is preferably 4 or less, more preferably 3.5 or less, and even more preferably 3 or less.

[0038] The weight-average molecular weight (Mw) of the alkenyl group-containing organopolysiloxane is preferably 5,000 to 100,000, more preferably 10,000 to 50,000, and even more preferably 15,000 to 35,000. By keeping the weight-average molecular weight of the alkenyl group-containing organopolysiloxane below the upper limit, it is possible to prevent a decrease in reactivity or the thermal conductivity of the composition from becoming too viscous. Furthermore, by keeping the weight-average molecular weight of the alkenyl group-containing organopolysiloxane above the lower limit, it is possible to prevent the crosslinking density from becoming too high, making it easier to ensure flexibility after curing. It is also possible to prevent the reactivity from becoming too fast, making it easier to ensure that the addition reaction proceeds appropriately. The weight-average molecular weight can be measured by gel permeation chromatography (GPC).

[0039] The functional group concentration of the alkenyl group-containing organopolysiloxane is preferably 1 μmol / g or more and 5000 μmol / g or less. When the functional group concentration is 1 μmol / g or more, the amount of alkenyl groups is above a certain level, and a crosslinked structure can be appropriately formed. On the other hand, when the functional group concentration is 5000 μmol / g or less, it is easier to prevent the crosslinking density from becoming too high and to ensure flexibility after curing. The functional group concentration of the alkenyl group-containing organopolysiloxane is more preferably 20 μmol / g or more and 1000 μmol / g or less, and even more preferably 50 μmol / g or more and 400 μmol / g or less. The functional group concentration (μmol / g) is the concentration of alkenyl groups in the alkenyl group-containing organopolysiloxane, and is typically the vinyl group concentration. The functional group concentration can be a value calculated from the integral ratio of the 1H-NMR spectrum measured using an NMR measuring device.

[0040] The alkenyl group in the alkenyl group-containing organopolysiloxane is not particularly limited, but examples include those having 2 to 8 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, and octenyl groups. Among these, the vinyl group is preferred from the viewpoint of ease of synthesis and reactivity. In the alkenyl group, the double bond is preferably located at the terminal end of the alkenyl group. Furthermore, the alkenyl group is preferably an alkenyl group directly bonded to a silicon atom. Examples of residual groups bonded to silicon atoms other than the alkenyl group include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl groups, aryl groups such as phenyl groups, and aralkyl groups such as 2-phenylethyl and 2-phenylpropyl groups. Substitutive hydrocarbon groups such as chloromethyl and 3,3,3-trifluoropropyl groups are also given as specific examples. Of these, hydrocarbon groups are preferred, and the methyl group is more preferred from the viewpoint of ease of synthesis. Furthermore, it is preferable that 80 mol% or more of the remaining groups bonded to the silicon atom are methyl groups, more preferably 90 mol% or more are methyl groups, and even more preferably 100 mol% are methyl groups. It should be noted that the alkenyl group-containing organopolysiloxane does not have a hydrogen atom as a remaining group bonded to the silicon atom; that is, the alkenyl group-containing organopolysiloxane does not contain a hydrosilyl group.

[0041] The content of the alkenyl group-containing organopolysiloxane is not particularly limited, but can be appropriately selected so that the H / Vi ratio, as described later, can be adjusted to a desired range. However, it is preferably 25% by mass or more and 95% by mass or less, and more preferably 30% by mass or more and 90% by mass or less, relative to the total amount of organopolysiloxane contained in the thermal conductive composition for forming the heat-dissipating molded article.

[0042] (Hydrosilyl group-containing organopolysiloxane) The resin component may contain a hydrosilyl group-containing organopolysiloxane as described above. By containing a hydrosilyl group-containing organopolysiloxane, the thermally conductive composition can undergo an addition reaction with an alkenyl group-containing organopolysiloxane to extend its chain and form a cured product with appropriate hardness. The hydrosilyl group-containing organopolysiloxane may have at least two functional hydrosilyl groups. Having two or more functional hydrosilyl groups allows the thermally conductive composition to cure properly and also introduces a crosslinked structure into the cured product.

[0043] The hydrosilyl group-containing organopolysiloxane may be linear or branched, or may contain a cyclic structure, or may be a mixture of two or more of these, but it is preferable that it contains a linear hydrosilyl group-containing organopolysiloxane. In the linear or branched hydrosilyl group-containing organopolysiloxane, the hydrosilyl group may be contained at either the end of the molecular chain of the polysiloxane structure or in the side chain, or it may be contained at both the end and the side chain, but it is preferable that it be contained at least at the end, and it is even more preferable that two hydrosilyl groups be contained at each end of the molecular chain of the polysiloxane structure. The number of functional groups (number of hydrosilyl groups in one molecule) of the linear or branched hydrosilyl group-containing organopolysiloxane is preferably 2 to 25, more preferably 3 to 20. The hydrosilyl group-containing organopolysiloxane is preferably liquid at 25°C.

[0044] The hydrosilyl group-containing organopolysiloxane may contain a hydrosilyl group-containing organopolysiloxane having a cyclic structure, but the amount is small, for example, 0.01% to 1% by mass, preferably 0.03% to 0.5% by mass, in the resin component. However, the hydrosilyl group-containing organopolysiloxane having a cyclic structure should have a high functional group concentration (i.e., hydrosilyl group concentration). Specifically, it is sufficient to use one with a concentration of approximately 1000 μmol / g to 20000 μmol / g, preferably 2000 μmol / g to 10000 μmol / g.

[0045] In hydrosilyl group-containing organopolysiloxanes, examples of residual groups bonded to silicon atoms other than the hydrosilyl group include alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, and dodecyl groups, aryl groups such as phenyl groups, and aralkyl groups such as 2-phenylethyl and 2-phenylpropyl groups. Substitutive hydrocarbon groups such as chloromethyl and 3,3,3-trifluoropropyl groups are also given as specific examples. Of these, the methyl group is preferred from the viewpoint of ease of synthesis. Furthermore, it is preferable that 80 mol% or more of the residual groups bonded to the silicon atoms are methyl groups, more preferably 90 mol% or more are methyl groups, and even more preferably 100 mol% are methyl groups. It is preferable that hydrosilyl group-containing organopolysiloxanes do not have alkenyl groups as residual groups bonded to the silicon atoms; that is, hydrosilyl group-containing organopolysiloxanes do not contain alkenyl groups. Hydrosilyl group-containing organopolysiloxanes may be used individually or in combination of two or more types.

[0046] The weight-average molecular weight (Mw) of the hydrosilyl group-containing organopolysiloxane is preferably 3,000 to 50,000, more preferably 5,000 to 20,000, and even more preferably 10,000 to 15,000. By keeping the weight-average molecular weight of the hydrosilyl group-containing organopolysiloxane below the upper limit, it is possible to prevent a decrease in reactivity or the thermally conductive composition from becoming highly viscous. Furthermore, by keeping the weight-average molecular weight of the hydrosilyl group-containing organopolysiloxane above the lower limit, it is possible to prevent the crosslinking density from becoming too high, making it easier to ensure flexibility after curing.

[0047] The content of the hydrosilyl group-containing organopolysiloxane is not particularly limited, but can be appropriately selected, for example, so that the H / Vi ratio described later can be adjusted to a desired range. However, it is preferably 4% by mass or more and 74% by mass or less, and more preferably 9% by mass or more and 69% by mass or less, relative to the total amount of organopolysiloxane contained in the thermal conductive composition.

[0048] The content of alkenyl group-containing organopolysiloxane and hydrosilyl group-containing organopolysiloxane is such that the ratio of hydrosilyl groups in the resin component to alkenyl groups in the resin component (H / Vi) is preferably 0.3 to 1.5, more preferably 0.4 to 1.0, on a molar basis. By adjusting H / Vi to a certain level or below, it becomes easier to impart tackiness to the silicone rubber, and it becomes easier to adjust the tack values ​​T2 and T2' to a certain level or above. H / Vi can be calculated from the hydrosilyl group concentration, alkenyl group concentration, and content of each component. Furthermore, the hydrosilyl group concentration and alkenyl group concentration of each component can be values ​​calculated from the integral ratio of the 1H-NMR spectrum measured using an NMR measuring device.

[0049] (Other Resin Components) The resin components included in the thermally conductive composition for forming the polymer matrix are not limited to the curable components described above, and may also include resin components other than the curable components. Examples of resin components other than the curable components include organopolysiloxanes other than hydrosilyl group-containing organopolysiloxanes and alkenyl group-containing organopolysiloxanes (also called other organopolysiloxanes). Specifically, examples include silicone oil, organopolysiloxanes having at least one alkoxy group (alkoxy group-containing organopolysiloxanes), organopolysiloxanes having at least one hydroxyl group (hydroxyl group-containing organopolysiloxanes), organopolysiloxanes having groups with aromatic structures such as pyrene and perylene, preferably polycyclic aromatic structures (aromatic group-containing organopolysiloxanes), and the like.

[0050] Examples of silicone oils include straight silicone oils such as dimethyl silicone oil and phenylmethyl silicone oil, as well as non-reactive modified silicone oils in which non-reactive organic groups are introduced into a main chain having a polysiloxane structure, side chains attached to the main chain, or the ends of the main chain. A non-reactive organic group is an organic group that does not have an addition reaction 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 preferred as the silicone oil, and among straight silicone oils, dimethyl silicone oil is more preferred. One type of silicone oil may be used alone, or two or more types may be used in combination.

[0051] The alkoxy group-containing organopolysiloxane may be linear, branched, or a mixture of linear and branched structures, but it is preferable that it be linear. Furthermore, the alkoxy group-containing organopolysiloxane may be any organopolysiloxane having at least one alkoxy group, but it is preferable that it has at least one alkoxy group at the end of the molecular chain of the polysiloxane structure, and it is more preferable that it has at least one alkoxy group at only one end. It is presumed that the alkoxy group-containing organopolysiloxane, by having alkoxy groups, especially alkoxy groups at the ends, readily reacts or interacts with functional groups present on the surface of the thermally conductive filler, and, combined with having a polysiloxane structure, reduces friction of the filler and makes it easier to lower the viscosity of the thermally conductive composition.

[0052] The alkoxy group-containing organopolysiloxane preferably has a group represented by the following formula (4), and the group represented by formula (4) is preferably bonded to the Si constituting the polysiloxane structure via a linking group. -SiR １ ａ (OR ２ ３－ａ ) (4) (Note that in equation (4), R １ , R ２ Each of these is independently a hydrocarbon group, preferably an alkyl group. １ , R ２ The number of carbon atoms is, for example, 1 to 8, preferably 1 to 4, more preferably 1 or 2. １ , R ２Preferred specific examples are methyl groups and ethyl groups. a is an integer from 0 to 2, preferably 0 or 1, more preferably 0. The linking group that links the group represented by formula (4) to Si is an oxygen atom, a divalent hydrocarbon group, or an ester structure, and is preferably a divalent hydrocarbon group. Examples of divalent hydrocarbon groups include those having about 1 to 8 carbon atoms, such as methylene groups, ethylene groups, propylene groups, butylene groups, and methylethylene groups, with ethylene groups being preferred. The alkoxy-containing organopolysiloxane has a siloxane skeleton (-Si-O-), and the number of repeating units n of the siloxane skeleton is, for example, 10 to 320, preferably 20 to 280, and more preferably 25 to 230.

[0053] A hydroxyl group-containing organopolysiloxane may have only one hydroxyl group or two or more hydroxyl groups. While there is no particular upper limit to the number of hydroxyl groups, it is preferable that the number be six or less, and more preferably three or less. Because the hydroxyl group-containing organopolysiloxane readily reacts or interacts with the functional groups on the surface of the thermally conductive filler, it enhances the dispersibility of the thermally conductive filler and makes it easier to reduce the viscosity of the composition. The number of hydroxyl groups in a hydroxyl-containing organopolysiloxane may be one, and it is preferable that the organopolysiloxane has a hydroxyl group at one end of the main chain. The hydroxyl group may be directly bonded to the end of the organopolysiloxane chain, but it is preferable that it is bonded via a linking group. A single hydroxyl group may be bonded to one Si via a linking group, or multiple (e.g., two or three) hydroxyl groups may be bonded to one Si via linking groups. The linking group is a hydrocarbon group that may include ester bonds, amide bonds, ether bonds, oxime ester bonds (-C=N-O-C(=O)-), and preferably a hydrocarbon group having an ether bond. The number of carbon atoms in the linking group is about 1 to 20, preferably 2 to 15, and more preferably 3 to 10. The organopolysiloxane having a hydroxyl group of the present invention has a siloxane skeleton (-Si-O-), and the number of repeating units n of the siloxane skeleton is preferably 11 to 350, more preferably 20 to 300, and even more preferably 50 to 270.

[0054] In addition, the specific explanation of the residual groups bonded to the silicon atom in alkoxy group-containing organopolysiloxanes and hydroxyl group-containing organopolysiloxanes is the same as for alkenyl group-containing organopolysiloxanes, so that explanation will be omitted. Furthermore, alkoxy group-containing organopolysiloxanes, hydroxyl group-containing organopolysiloxanes, or aromatic group-containing organopolysiloxanes are preferably liquid organopolysiloxanes at 25°C.

[0055] The content of other organopolysiloxanes in the resin component is not particularly limited, but is, for example, 0.1% by mass or more and 12% by mass or less, and preferably 0.5% by mass or more and 10% by mass or less.

[0056] Furthermore, the thermally conductive composition may contain resin components other than organopolysiloxane, as long as it achieves the effects of the present invention. However, in the resin components, organopolysiloxane is preferably the main component, and specifically, the content of organopolysiloxane may be, for example, 70% by mass or more and 100% by mass or less, preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably 100% by mass, relative to the total resin components. In other words, it is preferable that the resin components do not contain resin components other than organopolysiloxane.

[0057] The resin component content in the thermally conductive composition is preferably 10% by volume or more and 70% by volume or less. That is, the polymer matrix content in the heat-dissipating molded article is preferably 10% by volume or more and 70% by volume or less. When the above content is 30% by volume or more, the polymer matrix can properly hold the thermally conductive filler after curing. Also, when it is 70% by volume or less, it becomes easier to incorporate components other than the polymer matrix, such as the thermally conductive filler, into the heat-dissipating molded article. By incorporating a large amount of thermally conductive filler, it becomes easier to improve the thermal conductivity. The resin component content in the thermally conductive composition (i.e., the polymer matrix content in the heat-dissipating molded article) is more preferably 20% by volume or more and 60% by volume or less, and even more preferably 30% by volume or more and 50% by volume or less.

[0058] <Thermally Conductive Fillers> Examples of thermally conductive fillers include metal oxides, metal nitrides, metal hydroxides, carbon materials, non-metallic oxides, nitrides, carbides, and organic fibers. Using these thermally conductive fillers makes it easier to ensure the insulation properties of the heat-dissipating molded body. The shape of the thermally conductive fillers can be spherical, irregularly shaped powder, etc. Examples of metal oxides in thermally conductive fillers include aluminum oxide, represented by alumina, magnesium oxide, and zinc oxide. Examples of metal nitrides include aluminum nitride. Examples of metal hydroxides include aluminum hydroxide. Examples of carbon materials include diamond. Examples of non-metallic oxides, nitrides, and carbides include quartz, boron nitride, and silicon carbide. Examples of organic fibers include poly(p-phenylenebenzoxazole) fibers. Among these, from the viewpoint of improving thermal conductivity, metal oxides, metal nitrides, metal hydroxides, and carbon materials are preferred as thermally conductive fillers, and among these, metal oxides or metal hydroxides are more preferred. Specifically, aluminum oxide, aluminum hydroxide, and boron nitride are preferred as thermally conductive fillers, with aluminum oxide and aluminum hydroxide being more preferred, and it is even more preferable to include at least one selected from the group consisting of aluminum oxide and aluminum hydroxide. These thermally conductive fillers may be used individually or in combination of two or more. Furthermore, the thermally conductive fillers may be surface-treated with a surface treatment agent such as a silane coupling agent.

[0059] The average particle size of the thermal conductive filler is not particularly limited, but is preferably 0.1 to 200 μm, more preferably 0.3 to 100 μm, and even more preferably 0.5 to 70 μm. The average particle size of the thermal conductive filler is D50, which can be calculated by observing the thermal conductive filler under a microscope and taking the major axis as the diameter. For example, by measuring the major axes of 500 or more arbitrary particles using an electron microscope or optical microscope, it means the particle size corresponding to the cumulative frequency of 50%. More specifically, it can be determined from a particle size distribution curve with particle size on the horizontal axis and cumulative frequency on the vertical axis, using the thermal conductive filler as a sample. This particle size distribution curve is a number-based particle size distribution curve obtained by sequentially accumulating from the smallest particle size of the thermal conductive filler.

[0060] The content of the thermal conductive filler in the thermal conductive composition is preferably 30% by volume or more and 90% by volume or less. That is, the content of the polymer matrix in the heat-dissipating molded article is preferably 30% by volume or more and 90% by volume or less. A content of 35% by volume or more makes it easier to improve the thermal conductivity. Furthermore, by setting it to 80% by volume or less, the polymer matrix can properly hold the thermal conductive filler after curing. The content of the resin component in the thermal conductive composition (i.e., the content of the polymer matrix in the heat-dissipating molded article) is more preferably 40% by volume or more and 80% by volume or less, and even more preferably 50% by volume or more and 70% by volume or less.

[0061] The thermally conductive composition for forming the heat-dissipating molded article of the present invention may contain various additives. Examples of additives include silane coupling agents, curing catalysts, reaction regulators, dispersants, flame retardants, plasticizers, antioxidants, colorants, surface treatment agents, and thixotropic agents.

[0062] Among the above, it is preferable that the thermally conductive composition contains a curing catalyst. The curing catalyst can be any catalyst that promotes the addition reaction between an alkenyl group-containing organopolysiloxane and a hydrosilyl group-containing polysiloxane. By containing a curing catalyst, the thermally conductive composition can be appropriately cured and crosslinked. Examples of curing catalysts include platinum group curing catalysts. The amount of 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 is, for example, 0.0001 to 1 part by mass, preferably 0.001 to 0.5 parts by mass, per 100 parts by mass of organopolysiloxane contained in the thermally conductive composition.

[0063] [One-component or two-component thermal conductive composition] The thermal conductive composition in the present invention may be a one-component type or a two-component type comprising a first agent and a second agent. In the two-component type, the first agent and the second agent are mixed at the time of use to obtain the thermal conductive composition. In the case of the two-component type, it is preferable to appropriately distribute each component of the thermal conductive composition between the first agent and the second agent. For example, in a two-component thermal conductive composition, the first agent may contain an alkenyl group-containing organopolysiloxane and a curing catalyst, but may not contain a hydrosilyl group-containing organopolysiloxane. In this case, the second agent may contain a hydrosilyl group-containing organopolysiloxane but may not contain a curing catalyst. Furthermore, the second agent may further contain an alkenyl group-containing organopolysiloxane. Furthermore, it is preferable that at least one of the first and second components contains a thermally conductive filler, but it is preferable that both the first and second components contain a thermally conductive filler. In addition, other organopolysiloxanes, other resin components, and additives may be appropriately distributed between the first and second components.

[0064] A one-component thermal conductive composition can be obtained by appropriately mixing the components constituting the thermal conductive composition. A two-component thermal conductive composition can be obtained by preparing a first component and a second component by mixing the components constituting the first and second components respectively, and then mixing the first and second components. The method for mixing the first and second components to obtain the thermal conductive composition is not limited, but for example, a static mixer, a mixer with stirring blades, a vibrating agitator, or a rotational / revolving mixer can be used.

[0065] [Thermal Conductivity] The thermal conductivity of the heat-dissipating molded article of the present invention is preferably 1.0 W / (m·K) or higher. When the thermal conductivity of the heat-conducting molded article is 1.0 W / (m·K) or higher, the heat dissipation performance can be improved. From the viewpoint of further improving the heat dissipation performance, the above thermal conductivity is more preferably 1.5 W / (m·K) or higher, and even more preferably 2.0 W / (m·K) or higher. The upper limit of the thermal conductivity is not particularly limited, but in practical terms, it is, for example, 30 W / (m·K) or less, and preferably 10 W / (m·K) or less.

[0066] [Method for Manufacturing a Heat Dissipating Molded Body] A heat dissipating molded body can be manufactured by molding a thermally conductive resin composition using a mold. One method for molding a heat dissipating molded body is to use a compression mold, as shown below. The method for manufacturing a heat dissipating molded body using a compression mold will be described in detail below. This manufacturing method has the following steps (1) to (3). Step (1): A step of pouring a thermally conductive composition into a compression mold. Step (2): A step of heat curing the thermally conductive composition. Step (3): A step of obtaining a heat dissipating molded body by demolding the cured product of the thermally conductive composition from the mold.

[0067] <Step (1)> Step (1) is a step of pouring a heat-conductive composition into a compression mold. In this step, it is preferable to use a compression mold in which the cavity has a shape corresponding to the heat-dissipating molded body described above, and to pour the heat-conductive composition into the compression mold. A mold is generally used as the mold. The compression mold may consist of, for example, an upper mold and a lower mold. In this step, it is preferable to apply a reactive resin to at least a part of the inner surface of the compression mold before pouring the heat-conductive composition. By applying the reactive resin, a skin layer can be formed on at least a part of the heat-dissipating molded body as described later, and the tack values ​​T2 and T2' described above can be adjusted to a certain level or less. Here, the reactive resin only needs to be applied to the inner surface of the mold for forming the outer surface of the top surface, and it is preferable to apply it to the inner surface of the mold for forming the outer surface of the top surface and the outer surface of the wall surface. For example, if the mold has, for instance, an upper mold and a lower mold, the reactive resin may be applied to the inner surface of either one of them. If the mold consists of, for example, a male mold and a female mold, the reactive resin may be applied to the female mold. Furthermore, the reactive resin does not have to be applied directly to the compression mold. If a release film is installed inside the compression mold, the reactive resin may be applied to the surface of the release film. The method of applying the reactive resin is not particularly limited; for example, it may be applied by spraying or by using a brush, but spraying is preferred. By spraying, the reactive resin adheres more uniformly to the heat-dissipating molded body, making it easier to adjust the tack values ​​T2 and T2' to a constant level or lower without unevenness.

[0068] The reactive resin preferably has a viscosity of 50,000 mPa·s or less at room temperature (25°C), more preferably 10,000 mPa·s or less, and even more preferably 1,000 mPa·s or less. Having a viscosity below a certain level allows for uniform application of the reactive resin, making it easier to adjust the tack values ​​T2 and T2' of the heat-dissipating molded article to a certain level or less. From the viewpoint of ease of handling during application, the viscosity of the reactive resin at room temperature should, for example, be 1 mPa·s or more, preferably 50 mPa·s or more, and more preferably 100 mPa·s or more.

[0069] The reactive resin is not particularly limited as long as it reacts with the curable components constituting the polymer matrix and can form a skin layer by reacting with the curable components, but examples include components that make up the curing agent. For example, when the polymer matrix is ​​silicone rubber and an alkenyl group-containing organopolysiloxane and a hydrosilyl group-containing organopolysiloxane are used, the reactive resin is preferably a hydrosilyl group-containing organopolysiloxane. By using a curing agent such as a hydrosilyl group-containing organopolysiloxane, a highly cured skin layer is formed on the surface of the heat-dissipating molded article formed by the surface of the mold to which the reactive resin is coated, resulting in a surface with a lower tack value compared to other surfaces. Furthermore, when the polymer matrix is ​​urethane rubber, examples of reactive resins include polyisocyanate compounds, polyol compounds, or curing agents. Furthermore, when the polymer matrix is ​​acrylic rubber, examples of reactive resins include acrylic acid ester compounds, methacrylic acid ester compounds, and living polymerization agents.

[0070] The amount of reactive resin applied was 0.37 mg / cm². ２ Preferably, it is 0.6 mg / cm³. ２ It is more preferable that the concentration be greater than or equal to 0.8 mg / cm³. ２ It is even more preferable that the amount of reactive resin applied is greater than or equal to the lower limit mentioned above. By setting the amount of reactive resin applied to be greater than or equal to the lower limit, it becomes easier to adjust the tack values ​​T2 and T2' to a certain level or lower. Furthermore, the upper limit of the amount of reactive resin applied is not particularly limited, but from the viewpoint of effectively lowering the tack values ​​T2 and T2' without using excessive reactive resin, for example, 20 mg / cm² is preferred. ２ The following is acceptable, preferably 10 mg / cm³ ２ The following is more preferable: 1 mg / cm² ２ The following applies:

[0071] The application of the reactive resin does not necessarily have to be done in this step. For example, if secondary curing is performed as described later, the reactive resin may be applied directly to the primary cured heat-dissipating molded body after step (3) and before secondary curing. Alternatively, the reactive resin may be applied directly to the heat-dissipating molded body after secondary curing, in which case appropriate heating may be performed after application. When the reactive resin is applied directly to the heat-dissipating molded body, the application method is not particularly limited. For example, it may be applied by spray application, by using a brush, or by immersion in the reactive resin.

[0072] <Step (2)> Step (2) is a step of heat-curing the heat-conductive composition that has been cast into a compression mold. The curing conditions in this step are not particularly limited, but for example, heating can be performed at 80°C to 200°C for 30 seconds to 30 minutes, and it is preferable to cure by heating at 100°C to 160°C for 1 minute to 15 minutes.

[0073] <Step (3)> Step (3) is a step in which a heat-dissipating molded body is obtained by demolding a cured product of the heat-conductive composition from a compression mold. The method of demolding is not particularly limited, and for example, demolding may be performed using a known demolding jig. The heat-dissipating molded body obtained by demolding may be further secondary cured. Secondary curing may be performed by heating the heat-dissipating molded body. The heating conditions during secondary curing are not particularly limited, but for example, secondary curing may be performed at 100 to 200°C for about 30 minutes to 24 hours.

[0074] [Method for arranging the heat-dissipating molded body] The present invention also provides a method for arranging the heat-dissipating molded body described above. In the present invention, as shown in Figure 7(a), the flat portion 11A' which is the outer surface 11A of the top surface portion 11 is lifted by suction using the suction device 20. Then, as shown in Figure 7(b), the suction device 20 is moved so that the inner surface of the heat-dissipating molded body 10 is in contact with the workpiece 21, and the suction of the suction device 20 is stopped to arrange the heat-dissipating molded body 10 on the workpiece 21. By adopting this arrangement method, pick-and-place processing by automation becomes possible.

[0075] The suction device 20 is not particularly limited, and a known suction device usable in an automated pick-and-place process may be used. The suction force when the flat portion 11A' is sucked by the suction device 20 is preferably 70 mPa or more, preferably 84 mPa or more, and more preferably 100 mPa or more. By setting the suction force above a certain level, the suction device 20 can be moved appropriately to the position of the adherend 21 without dropping the heat dissipation molded body 10 while the flat portion 11A' is being sucked. From the viewpoint of preventing damage or deformation of the heat dissipation molded body 10, the suction force is preferably 91 kPa or less, preferably 50 kPa or less, and more preferably 10 kPa or less.

[0076] The suction device 20 should be moved to the position of the object to be attached 21 while the flat portion 11A' is being sucked, and then the suction should be stopped. By stopping the suction, the heat dissipation molded body 10 is released from the suction device 20, and the heat dissipation molded body 10 can be attached to the object to be attached 21. The object to be attached 21 is preferably a heat dissipation body such as a housing, which will be described later, but it may also be a heat-generating body such as a heat-generating conductive member.

[0077] In this arrangement method, the tack value T1 of the outer surface of the heat dissipation molded body 10 is 20 mN / mm ２ More than 67mN / mm ２ The following conditions must be met, and if Y is the contact area between the heat dissipation molded body 10 and the suction device 20, and X is the tack value T1, then it is preferable that X and Y satisfy the relationship shown in the following equation (1): 0 < Y < -1.8X + 100 Equation (1) By satisfying these conditions, the heat dissipation molded body 10 is more easily released from the suction device 20 when suction is stopped. Note that the contact area Y is the contact area between the heat dissipation molded body 10 and the suction pad if the suction device 20 has a suction pad described later, and the unit is mm as described later. ２ That is the case.

[0078] The contact area Y between the heat dissipation molded body 10 and the suction device 20 is 60 mm². ２ The following is preferable: 50 mm ２ More preferably, the following: 30 mm ２The following is even more preferable: By keeping the contact area Y below a certain level, the heat dissipation molded body 10 is more easily released from the suction device 20 when suction is stopped. Also, the contact area Y is 5 mm from the viewpoint of making it easier for the suction device 20 to adsorb the flat portion 11A'. ２ Preferably, it is 10 mm or more ２ More preferably, the amount is 15 mm or more. ２ It is even more preferable that the above conditions are met.

[0079] The suction device 20 preferably has an suction pad. Having an suction pad makes it easier to adsorb the flat portion 11A', and makes it easier to move the suction device 20 to the position of the object to be attached 21 while the flat portion 11A' is being adsorbed. The material of the suction pad is not particularly limited, but examples include rubbers such as silicone rubber, styrene-butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, acrylonitrile-butadiene rubber, nitrile-butadiene rubber, butyl rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, urethane rubber, silicone rubber, and fluororubber, as well as fluororesins. Among these, at least one of silicone rubber, fluororubber, and fluororesins is preferred, and silicone rubber is more preferred.

[0080] [Applications of the heat-dissipating molded body] The heat-dissipating molded body 10 is preferably used for electronic component devices equipped with heat-generating conductive members. Preferably, the heat-dissipating molded body 10 is used to dissipate heat generated from the heat-generating conductive member by having at least a portion of it in contact with the heat-generating conductive member of the electronic component device.

[0081] The heat-generating conductive member is an electrode member or the like, as described later, and only needs to be in contact with a part of the heat-dissipating molded body 10, but preferably it is in contact with the outer surface 11A of the top surface 11. In addition, the electronic component device may be equipped with a heat sink such as a housing in addition to the heat-generating conductive member. The housing only needs to be in contact with a part of the heat-dissipating molded body 10, but if the heat-generating conductive member is in contact with the outer surface 11A, at least a part of it should be in contact with the inner surface 11B of the top surface 11. With the above configuration, the heat generated by the heat-generating conductive member can be easily conducted to the housing via the top surface 11 and dissipated from the housing. Furthermore, insulation between the member inside the recess 14 and the member on the outer surface 11A of the top surface 11 can be ensured, so it can be suitably used for heat dissipation of the heat-generating conductive member.

[0082] Here, the heat-generating conductive member may have at least one surface in close contact with the outer surface 11A of the top surface 11, and the heat-generating conductive member may adhere to the outer surface 11A. Similarly, the housing may have at least one surface that adheres to the inner surface 11B of the top surface 11. The housing may have, for example, a columnar portion, which is inserted into the recess, and the tip surface of the columnar portion may adhere to the inner surface 11B of the top surface 11. In other words, the housing may be an object to be attached to be inserted into the recess. Furthermore, the outer circumferential surface of the columnar portion of the housing may have a shape corresponding to the inner surface of the wall portion 12. For example, if the wall portion 12 of the heat-dissipating molded body 10 has a rectangular shape as shown in Figure 1, the columnar portion may have four sides corresponding to the side wall portions 13A to 13D. The housing may be fitted into the recess 14 and arranged to enclose the top surface 11 and the wall portion 12. The heat dissipation molded body 10 can be incorporated into an electronic component device without shifting position from the housing by inserting its columnar portion into its recess 14 and attaching it to the housing. The side surface of the columnar portion of the housing should be in close contact, preferably adhesive, with the inner surface of the wall portion 12 (i.e., the side wall portions 13A to 13D) of the heat dissipation molded body 10, thereby more effectively preventing the heat dissipation molded body 10 from shifting position.

[0083] The above configuration is merely an example, and the shape of the housing can be adjusted as appropriate to match the shape of the recess. If the flat surface is circular, the columnar part of the housing can be cylindrical. Furthermore, the housing does not need to have a columnar component in the recess; components other than columnar parts may be placed inside the recess.

[0084] In electronic component devices, heat-generating conductive members include members that generate heat when an electric current flows through them, and electrode members are preferred, with examples including busbars, lithium-ion batteries, onboard chargers, battery disconnection units, and conductive members in junction boxes. Among these, busbars are more preferred. Busbars tend to generate heat when a high voltage is applied, but by using the heat-dissipating molded body of the present invention, heat can be efficiently dissipated. Materials that constitute the heat-generating conductive member include metallic materials such as gold, silver, copper, or alloys containing any of these, carbon materials such as graphite, and metal oxides such as indium tin oxide, tin oxide conductive film, and zinc oxide, but among these, metallic materials are preferred from the viewpoint of high conductivity.

[0085] The housing is a component through which heat generated by the heat-generating conductive member is transmitted via the heat-dissipating molded body 10. The housing is a heat sink that further releases the transmitted heat to the outside. The housing may constitute part of the enclosure of the electronic component device, or it may be a component other than the enclosure. The housing may be made of a metal material, a resin material, graphite, etc. Furthermore, it may be preferable to have a chiller flowing inside the housing, for example, to have a chiller flowing inside the columnar part. The heat dissipation performance of the housing is improved by having a chiller flowing inside.

[0086] In the above description, a configuration was described in which the heat-generating conductive member contacts the outer surface 11A of the top surface 11, while the housing contacts the inner surface 11B of the top surface 11. However, in the present invention, a configuration in which the housing contacts the outer surface 11A of the top surface 11 and the heat-generating conductive member contacts the inner surface 11B of the top surface 11 may also be adopted, as long as the heat-dissipating molded body 10 performs its heat-dissipating role.

[0087] The electronic component device is not particularly limited as long as it has a heat-dissipating molded body 10 and a heat-generating conductive member, but it may be used as an electrical component in various electrical devices or as an automotive electrical component. Because the electronic component device can accommodate space saving, it is suitably used in various miniaturized electrical devices and automotive electrical components. Furthermore, the electronic component device is preferably used in batteries, more preferably in lithium batteries, and even more preferably in automotive lithium batteries.

[0088] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples.

[0089] In this example, the following method was used for evaluation: [Tack value] The heat dissipation molded bodies obtained in each example and comparative example were attached to a jig of a tack tester (TA-500, manufactured by UBM Co., Ltd.), and tested under conditions of 23°C and 50% relative humidity, with a speed of 0.7 mm / second and a contact time of 10 seconds, using a probe (cross-sectional area 0.195 cm²). ２ The tack value T1 was measured from the maximum load when the probe was pressed against the surface of the heat-dissipating molded body coated with reactive resin and pulled at 0.7 mm / second. The tack value T2 was measured in the same manner as the tack value T1, except that the probe was pressed against a surface that was not coated with reactive resin.

[0090] [Handling] A suction device (SMC Corporation's "ZK2B10R5NL3-06-J") was prepared, and a suction pad was attached to the suction device. Then, the suction pad attached to the suction device was brought into contact with the outer surface of the top surface of the heat dissipation molded body obtained in each example and comparative example, and the suction device was used to apply suction at a force of 100 mPa for 4 seconds, after which the suction was stopped. The handling of the heat dissipation molded body was evaluated using the above procedure. The evaluation criteria are as follows: A: The heat dissipation molded body separated from the suction pad at the same time as the suction stopped. B: The heat dissipation molded body separated from the suction pad within 1 second of the suction stopping. C: The heat dissipation molded body separated from the suction pad 1 to 2 seconds after the suction stopped. D: The heat dissipation molded body did not separate from the suction pad despite the suction stopping.

[0091] [Components used in the manufacture of the heat-dissipating molded body] ・Organopolysiloxane (a mixture of vinyl group-containing organopolysiloxane and hydrosilyl group-containing organopolysiloxane: ratio of hydrosilyl groups to alkenyl groups 0.62 (molar basis)) ・Platinum-based catalyst ・Aluminum oxide (1) (average particle size 45 μm) ・Aluminum oxide (2) (average particle size 2.4 μm) ・Aluminum oxide (3) (average particle size 4.7 μm)

[0092] [Reactive resins] ・Organopolysiloxanes containing hydrosilyl groups

[0093] [Adhesive Pads] ・Adhesive pad (1): Fluororubber material ・Adhesive pad (2): Silicone rubber material

[0094] [Example 1] A thermally conductive resin composition was obtained by mixing 115 parts by mass of organopolysiloxane, a catalytic amount of platinum-based catalyst, 550 parts by mass of aluminum oxide (1) with an average particle size of 45 μm, 55 parts by mass of aluminum oxide (2) with an average particle size of 2.4 μm, and 220 parts by mass of aluminum oxide (3) with an average particle size of 4.7 μm. The thermally conductive filler content in the thermally conductive resin composition (thermally conductive resin member) was 65 volume%. Then, a mold corresponding to the shape shown in Figures 1 and 2 was prepared, and the reactive resin was applied to the upper surface of the mold at a rate of 0.37 mg / cm³. ２ After spray coating at a coating speed of / sec. for 2 seconds, the thermal conductive composition was introduced into a mold and molded at a molding temperature of 120°C for 8 minutes to obtain a heat-dissipating molded body. Ten heat-dissipating molded bodies were prepared and designated as samples No. 1 to 10. The above-mentioned physical properties were measured and evaluated for each of the obtained heat-dissipating molded bodies. For the evaluation of handling ease, an adsorption pad (1) was attached to the suction device. The contact area between the adsorption pad (1) and the heat-dissipating molded body was 34.56 mm². ２ That was the case.

[0095] [Example 2, Comparative Example 1] The procedure was carried out in the same manner as in Example 1, except that the coating time of the reactive resin was changed as shown in Table 1.

[0096]

[0097] [Examples 3-4, Comparative Example 2] The process was carried out in the same manner as in Example 1, except that the coating time of the reactive resin was changed as shown in Table 2, two heat-dissipating molded bodies were prepared and designated as Samples 1 and 2, respectively, and the suction pad attached to the suction device was changed to suction pad (2). The contact area between suction pad (2) and the heat-dissipating molded body was 21.21 mm². ２ That was the case.

[0098]

[0099] As is clear from the above results, the heat dissipation molded body produced in the example had a tack value T1 on the outer surface that was smaller than the tack value T2 on the inner surface. Therefore, it can be understood that the inner surface had sufficient adhesiveness to adhere to the adherend, while the outer surface detached from the suction pad when suction was stopped, allowing the heat dissipation molded body to be attached without shifting its position. In contrast, the heat dissipation molded body produced in the comparative example did not have a sufficiently small tack value T1 on the outer surface, so the outer surface did not detach from the suction pad when suction was stopped, and it could be understood that it did not have the ability to be attached without shifting the position of the heat dissipation molded body.

[0100] 10 Heat dissipation molded body 11 Top surface 11A Outer surface 11A' Flat surface 11B Inner surface 12 Wall surface 13A, 13B, 13C, 13D Side wall 14 Recess 20 Suction device 21 Adhered object 26 Flange D1 Thickness of top surface D2 Thickness of wall surface D3 Thickness of flange L1 Length of wall surface L3 Contact length L4 Length of flange

Claims

1. A heat-dissipating molded body comprising a top surface having a flat surface, a wall surface provided on the outer periphery of the top surface, and a recess formed by the top surface and the wall surface, wherein the top surface has an outer surface which is the surface opposite to the recess and an inner surface which is the surface on the recess side, and the tack value T1 of the outer surface is smaller than the tack value T2 of the inner surface.

2. The heat dissipation molded body according to claim 1, wherein the tack value T1' of the outer surface of the wall portion is smaller than the tack value T2' of the inner surface of the wall portion.

3. A heat-dissipating molded article according to claim 1 or 2, comprising a polymer matrix and a thermally conductive filler.

4. The heat dissipation molded body according to claim 1 or 2, wherein the shape of the heat dissipation molded body is a cap shape.

5. The heat dissipation molded body according to claim 1 or 2, wherein at least a portion of the heat dissipation molded body is in contact with a heat-generating conductive member of an electronic component device, and is used to dissipate heat generated from the heat-generating conductive member.

6. The tack value T1 of the outer surface is 40 mN / mm ２ The following conditions apply, and the tack value T2 of the inner surface is 60 mN / mm ２ The heat-dissipating molded body according to claim 1 or 2.

7. A method for manufacturing a heat-dissipating molded body, comprising the steps of: pouring a heat-conductive composition into a compression mold; heating and curing the heat-conductive composition; and demolding the cured product of the heat-conductive composition from the compression mold to obtain a heat-dissipating molded body, wherein the heat-dissipating molded body comprises: a top surface having a flat surface; a wall surface provided on the outer periphery of the top surface; and a recess formed by the top surface and the wall surface; the top surface has an outer surface which is the surface opposite to the recess and an inner surface which is the surface on the recess side; and the tack value T1 of the outer surface is smaller than the tack value T2 of the inner surface.

8. The method for producing a heat-dissipating molded article according to claim 7, wherein in the step of casting the heat-conducting composition, a reactive resin is applied to at least a portion of the inner surface of the compression mold.

9. The method for manufacturing a heat-dissipating molded article according to claim 8, wherein the reactive resin is applied by spray coating.

10. The method for producing a heat-dissipating molded article according to claim 8, wherein the viscosity of the reactive resin at room temperature is 50,000 mPa·s or less.

11. The amount of the reactive resin applied is 0.37 mg / cm². ２ The method for manufacturing a heat-dissipating molded article according to claim 8.

12. A method for arranging a heat-dissipating molded body, wherein the heat-dissipating molded body comprises a top surface having a flat surface, a wall surface provided on the outer periphery of the top surface, and a recess formed by the top surface and the wall surface, the top surface having an outer surface which is the surface opposite to the recess and an inner surface which is the surface on the recess side, and the method for arranging a heat-dissipating molded body comprising: lifting the flat surface by suction with a suction device, moving the suction device so that the inner surface is in contact with the object to be attached, and stopping the suction of the suction device.

13. The tack value T1 of the outer surface is 20 mN / mm ２ More than 67mN / mm ２ The method for arranging a heat-dissipating molded body according to claim 12, wherein the following conditions are met, and if Y is the contact area between the heat-dissipating molded body and the suction device, and X is the tack value T1, then X and Y satisfy the relationship shown in the following formula (1): 0 < Y < -1.8X + 100 Formula (1) 14. The method for arranging a heat dissipation molded body according to claim 12 or 13, wherein the suction device has an adsorption pad, and the material of the adsorption pad is silicone rubber.

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