JP2005307130A - Heat-conductive alumina cement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-conductive alumina cement effective for simplifying the peeling work in the case of maintenance, inspection, recycling or disposal taking consideration of the bonding property and heat-dissipation and capable of suppressing the cost of the facilities, etc., for the peeling work. <P>SOLUTION: The heat-conductive alumina cement is produced by adding a filler to a binder composed of a heat-conductive powdery material and an adhesive elastic polymer material and kneading the mixture to obtain a clay-like product. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an aluminum plate or an iron plate and a heat conductive bonding agent that is interposed between an aluminum chassis and a glass panel in a glass plate holding heat, such as a plasma display panel, and bonding the two.

  A plasma display panel or the like generates a large amount of heat because of its structure and function, and must be at a high temperature. Therefore, it is important not only to ensure sufficient bondability even at high temperatures, but also how to efficiently dissipate heat because of high temperatures. Furthermore, when carrying out maintenance inspections, recycling or disposal, it is necessary to separate the glass plate and the metal plate such as an aluminum plate, and therefore, there is a conflicting function that both the bondability and the peelability must be good. It is required.

  Conventionally, the heat that the glass plate has is effectively sent to the aluminum plate with good heat conductivity, and heat dissipation is performed efficiently. A method of mixing a heat conductive material in the agent is used. For example, there is a double-sided adhesive sheet that bonds a chassis portion of a flat panel and a glass panel, and the double-sided adhesive sheet has a heat radiation function layer and a light shielding member interposed as a base material. (Patent Document 1) In this prior art, since the heat radiation function layer is interposed as a base material, it is possible to effectively send the heat of the glass plate to the chassis part side, and as a re-peeling mechanism, pressure sensitivity Use adhesives, etc. to suppress adhesion progress by adjusting the functional group, etc. to improve removability, and apply heat, light, electron beam, ultrasonic energy, etc. to cure and agglomerate the adhesive layer Easy to peel off by using a microcapsule containing a foaming agent, a curing agent, or a substance that reduces the adhesive strength such as oil, and destroying the microcapsule by stimuli such as pressure or heat. It has become contents to do.

Furthermore, as another prior art, there is a urethane-based pressure-sensitive adhesive composition containing a thermal conductivity imparting agent. In addition, this prior art limits the content ratio of the thermal conductivity imparting agent, and the material of the thermal conductivity imparting agent Is limited to alumina, or the softening point (120 to 200 ° C.) and shape (sheet shape) are limited. (Patent Document 2) In this prior art, by containing a thermal conductivity imparting agent, the heat of the glass panel is effectively sent to the aluminum chassis side, and the content ratio of the thermal conductivity imparting agent, etc. By limiting, the adhesiveness and heat dissipation are balanced, and the glass panel and the aluminum chassis are easily separated by softening and melting at a temperature slightly exceeding 100 ° C.
JP 2003-321654 A JP2002-121529

  As mentioned above, in the bonding agent that joins an aluminum plate or an iron plate and a glass plate, in order to effectively send the relatively high temperature heat possessed by the glass plate to the aluminum plate or the iron plate side, and efficiently dissipate heat. There exists what has a heat dissipation functional layer or contains a thermal conductivity-imparting agent. In addition, these prior arts are considered to be easily peeled in consideration of recycling or disposal.

  However, it is a very difficult problem because it has to have the contradictory functions of bondability and peelability at relatively high temperatures. Even in the above prior art, when peeling, energy such as heat, light, electron beam, and ultrasonic waves is applied to harden and agglomerate the adhesive layer, or the adhesive strength of foaming agent, curing agent or oil is reduced. When using a microcapsule that encapsulates what is to be destroyed, the microcapsule is broken by stimulation such as pressure or heat, or the adhesive is softened and melted at a certain temperature. The heat is slightly overheated, the peeling work is not easy, and the cost of the equipment can never be overlooked.

  In view of such conventional technology, the present invention further simplifies the peeling work when performing maintenance and inspection, recycling or disposal, while taking into consideration the bonding properties and heat dissipation, and the equipment for performing the peeling work, etc. An object of the present invention is to provide a thermally conductive alumina bonding agent that can keep costs low.

  In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a powdery heat conductive material and a binder which is an adhesive and elastic polymer material are kneaded with a filler and kneaded. It is a thing. With such a configuration, the aluminum plate or the iron plate and the glass plate in the plasma display panel or the like having a relatively high temperature are surely joined, and the heat of the glass plate having a relatively high temperature is made of aluminum. The glass plate and the aluminum plate or the iron plate can be effectively conducted to the side of the plate and the iron plate to efficiently dissipate the heat, and by applying a suitable external force to the glass plate or the aluminum plate or the iron plate by making the clay. Thus, it is possible to provide a thermally conductive alumina bonding agent capable of releasing the bonding.

  According to a second aspect of the present invention, the thermally conductive material is alumina fine powder, the elastic polymer material as the binder is one of butyl rubber, silicon rubber, and acrylic rubber, and the filler is a fine powder of calcium carbonate. It is a powder. By comprising in this way, the heat conductive alumina joining agent which is excellent in heat conductivity and inexpensive also can be provided.

  In the invention according to claim 3, the mixing ratio of the heat conductive material, the binder and the filler is 50 to 70% by weight of the heat conductive material, 30 to 15% by weight of the binder, and 20 to 15% by weight of the filler. Is. With such a configuration, the aluminum plate or the iron plate and the glass plate in a plasma display panel or the like having a relatively high temperature can be bonded to each other, and the heat of the glass plate having a relatively high temperature can be reduced to the aluminum plate or It is possible to provide a heat conductive alumina bonding agent that further improves the heat dissipation efficiency of efficiently sending to the iron plate side, and further the releasability of peeling the bond between the glass plate and the aluminum plate or the iron plate.

  The invention according to claim 4 has a hardness of 20 ° to 50 ° (test method JISK2207; 50 g load, 25 ° C.) when kneaded into a clay. By being configured in this way, it is possible to easily perform application work to an application object such as an aluminum plate, an iron plate, or a glass plate while ensuring bonding and heat dissipation, and a glass plate and an aluminum plate or an iron plate Thus, it is possible to provide a heat conductive alumina bonding agent having further improved releasability for peeling the bonding.

  Since the present invention is configured as described above, the following effects can be obtained.

  The heat conductive alumina bonding agent according to the present invention is made of a clay-like material by adding a filler to a binder that is an adhesive and elastic polymer material that is sticky to a powdery heat conductive material. The aluminum plate or the iron plate and the glass plate in the plasma display panel that becomes high temperature are securely joined, and the heat of the glass plate having a relatively high temperature heat is effectively conducted to the aluminum plate or the iron plate side. It is possible to efficiently dissipate heat and maintain an appropriate adhesion state, while hardening and agglomerating the adhesive layer, encapsulating those that lower the adhesive force, or applying heat that slightly exceeds 100 ° C. It is possible to peel off the bonding between the glass plate and the aluminum plate or iron plate with a simple operation of applying an appropriate external force to the glass plate, aluminum plate or iron plate without taking special measures to soften and melt the agent. In addition, aluminum plate, iron plate, and glass plate, in other words, plasma display panels can be used stably, while keeping the cost of equipment, etc. low, for maintenance and inspection and for recycling or disposal. It can be done very easily and neatly without leaving a residue. And by making it clay-like, generation | occurrence | production of the bubble by the unevenness | corrugation of the joint surface which influences joining property, for example, an aluminum plate surface, can also be prevented.

  Furthermore, in the heat conductive alumina bonding agent according to the present invention, the heat conductive material is alumina fine powder, and the elastic polymer material as the binder is one of butyl rubber, silicon rubber, and acrylic rubber, and the filler Is a fine powder of calcium carbonate, so that excellent thermal conductivity can be obtained while having reliable bondability and peelability, and can be provided at low cost.

  Furthermore, the thermally conductive alumina bonding agent according to the present invention is a mixture ratio of the thermally conductive material, the binder and the filler, 50 to 70% by weight of the thermally conductive material, 30 to 15% by weight of the binder and 20 to 20% of the filler. Since each material is mixed properly with 15% by weight, it retains the bondability between the aluminum plate or the iron plate and the glass plate in a plasma display panel, etc., which has a relatively high temperature, and the heat at a relatively high temperature. The heat dissipation of efficiently sending the heat of the glass plate to the aluminum plate or the iron plate side, and further improving the peelability of peeling the bonding between the glass plate and the aluminum plate or the iron plate, in other words, the aluminum plate or the iron plate and the glass plate While being able to use the plasma display panel more stably and keeping the costs of equipment, etc. low, the maintenance work and the peeling work in the case of recycling or disposal, Agent clean can be done very easily without leaving.

  Furthermore, since the heat conductive alumina bonding agent according to the present invention has an appropriate hardness of 20 ° to 50 ° (test method JISK2207; 50 g load, 25 ° C.) when kneaded to form a clay, Removability that peels off the bonding between the glass plate and the aluminum plate or iron plate, making it easy to apply to the object such as aluminum plate, iron plate or glass plate while ensuring bonding and heat dissipation. This makes it possible to use aluminum plates, iron plates, and glass plates, in other words, plasma display panels, etc. more stably, and to clean up and clean up when carrying out maintenance inspections and recycling or disposal. It can be done easily.

  Hereinafter, embodiments of the present invention will be described in detail. In the present invention, the bonding agent is a clay-like material that is kneaded by adding a powdery heat conductive material as a base material and a binder and a filler that are adhesive and elastic polymer materials. Basic composition.

  As described above, the bonding agent that bonds the aluminum chassis and glass panel in plasma display panels, etc., is not simply a bonding, and the bonding property is ensured even in a relatively high temperature environment. Further, thermal conductivity, that is, heat dissipation is also important, and in addition, it is extremely difficult to require peelability if necessary. Therefore, what is the composition of the bonding agent, that is, what is the material of the heat conductive material and the binder, what ratio is mixed, and no additional filler is required, It is important what and how much should be added if necessary. In addition, the mixing ratio must be determined while confirming the effect by various tests.

  Under such circumstances, the applicant conducted various tests. As a result, the basic composition of the bonding agent is kneaded into a clay with the addition of a powdery thermally conductive material and a binder and filler, which are sticky and elastic polymer materials, as already explained. It was confirmed that what was done was effective.

  Furthermore, as a heat conductive material, not only has excellent heat conductivity, but also a versatile and relatively inexpensive alumina fine powder is used as an elastic polymer material as a binder. Found that it is advantageous to use one of butyl rubber, silicon rubber, or acrylic rubber, and to use calcium carbonate fine powder as the filler. This is because butyl rubber, silicon rubber, acrylic rubber, and calcium carbonate fine powder, as well as the alumina fine powder, not only have a performance suitable for the purpose of use, but also have versatility and relatively low cost. Because it is cheap. In addition to the alumina fine powder, it has been found that aluminum hydroxide fine powder, copper or iron fine powder, and magnesium hydroxide fine powder can be used as the heat conductive material. And butyl rubber, silicon rubber, acrylic rubber as a binder does not necessarily have to be used alone, but because it is advantageous that there is no trouble such as studying and adjusting the mixed contents alone, butyl rubber and It was confirmed that a plurality of materials such as silicon rubber could be used together. Still further, the binder used is not limited to butyl rubber, silicon rubber, and acrylic rubber, and for example, urethane rubber or the like can be used.

  Next, the composition ratio of the bonding agent, that is, the mixing ratio of the fine powder of alumina fine powder as a heat conductive material, fine powder of butyl rubber, silicon rubber or acrylic rubber as a binder and calcium carbonate carbonate as a filler will be described. When the result of the test is shown by mass fraction method, the binder (any one of butyl rubber, silicon rubber, and acrylic rubber) is used when the fine powder of alumina, which is a heat conductive material, is 50 to 70% by weight. Corresponding to the material, 30 to 15% by weight, similarly, the fine powder of calcium carbonate as a filler was 20 to 15% by weight. It was also confirmed that there was almost no difference in the mixing ratio depending on the type of binder (butyl rubber, silicon rubber, acrylic rubber). In addition, aluminum hydroxide fine powder, copper or iron fine powder, and magnesium hydroxide fine powder, which are heat conductive materials other than alumina fine powder, were individually replaced with alumina fine powder. It was found that it can be used without changing the mixing ratio.

  The bonding agent obtained at such a mixing ratio is clay-like, but the hardness (softness) in that case is very important because it greatly affects the bonding property, workability when applied, and peelability. It is an important part. In the present invention, good results are obtained by setting the hardness to about 20 ° to 50 ° (test method JISK2207; 50 g load, 25 ° C.). When the hardness is set in this manner, it is suitable for bondability, workability in application, and releasability, as well as generation of bubbles that greatly affect the bondability. There are irregularities on the surface of the aluminum plate or iron plate (usually there are very small irregularities on the metal surface), and when bonded, bubbles remain in the irregularities and adversely affect the bonding properties. This is because the bonding agent enters into the concavo-convex portion and removes the bubbles by applying an appropriate pressing force after bonding together.

  Subsequently, a method of using the bonding agent thus obtained will be described with reference to FIGS. FIG. 1 is a perspective view showing an embodiment in which an aluminum plate and a glass plate are joined using a thermally conductive alumina bonding agent according to the present invention. The bonding method is performed by first applying a required amount of the bonding agent 3 to either one of the aluminum plate 1 and the glass plate 2 by an appropriate method such as brushing. Then, either the rear aluminum plate 1 or the glass plate 2 is bonded together and pressed with a suitable pressing force to finish. Of course, since a predetermined time is required for the bonding agent to fully exhibit the bonding effect, it goes without saying that the bonding agent can be safely maintained for a certain period of time after the bonding operation is completed.

  Further, as another bonding method, a bonding agent can be used as an adhesive tape. FIG. 2 shows an embodiment in which the thermally conductive alumina bonding agent according to the present invention is used as an adhesive tape. The adhesive tape 4 is formed by flattening the bonding agent 3 on one surface of a release film 5. It has been applied in the shape. A bonding method in the case of using such an adhesive tape is performed by bonding the adhesive surface side of the adhesive tape 4 to one side of either the aluminum plate 1 or the glass plate 2. Then, after the rear release film 5 is peeled off, either the aluminum plate 1 or the glass plate 2 is bonded together, and the pressing is completed with an appropriate pressing force. The holding for a certain period of time after the end of the joining operation is the same as the case of directly applying the bonding agent to the aluminum plate 1 or the glass plate 2.

  Next, in the process of testing the thermally conductive alumina bonding agent according to the present invention, it has been found that a new utilization method is possible by changing the composition. The content of the heat conductive alumina bonding agent is a clay using a fine powder of stone or shell instead of fine powder of alumina. This bonding agent is applied to the base of the place where floor tiles (wooden tiles, non-woven fabric tiles, plastic tiles, etc.) are pasted, and when the tiles are pasted on top of them, there is a sound absorption effect. It was found that there was a big effect on the soundproofing of the floor. Furthermore, the shell used as a composition is an industrial waste whose treatment is a problem, and is also effective as a reuse of industrial waste. In addition, as described above, metallic fine powders such as copper and iron can be used in the bonding agent of the present invention instead of alumina fine powder as a heat conductive material. It has been found that the bonding material has functions such as sound absorption and resonance prevention, and development is proceeding with a view to using it for audio equipment.

It is a perspective view which shows one Example which joined the aluminum plate and the glass plate using the heat conductive alumina bonding agent by this invention. It is a perspective view which shows one Example using the heat conductive alumina bonding agent by this invention as an adhesive tape.

Explanation of symbols

1 Aluminum plate 2 Glass plate 3 Bonding agent (thermally conductive alumina bonding agent)
4 Adhesive tape 5 Release film

Claims (4)

  A heat conductive alumina bonding agent characterized by adding a filler to a powdery heat conductive material and a binder which is a sticky and elastic polymer material and kneading it to form a clay.   The heat conductive material is alumina fine powder, the elastic polymer material as a binder is one of butyl rubber, silicon rubber, and acrylic rubber, and the filler is fine powder of calcium carbonate. The heat conductive alumina bonding agent according to claim 1.   The mixing ratio of the heat conductive material, the binder and the filler is 50 to 70% by weight of the heat conductive material, 30 to 15% by weight of the binder, and 20 to 15% by weight of the filler. 2. The thermally conductive alumina bonding agent according to 2.   The heat conductive alumina joint according to claims 1 to 3, wherein the hardness when kneaded into clay is 20 ° to 50 ° (test method JISK2207; 50 g load, 25 ° C). Agent.

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