JP2019157037A - Heat-insulation coating composition for vehicle floor panel, heat-insulation coating film, vehicle floor panel and vehicle floor tunnel structure - Google Patents

Abstract

To provide a heat-insulation coating composition that has a high heat-resistance and heat-insulation property and can save space of a heat insulation structure around a high-temperature heat source and that can form a heat-insulation structure with high productivity.SOLUTION: A heat-insulation coating composition containing a hollow particle and a silicone resin is applied to the inner wall surface of a tunnel of a floor panel main body 21 that forms a floor tunnel 40, to form a heat-insulation layer 10 comprising a heat-insulation coating film.SELECTED DRAWING: Figure 2

Description

  TECHNICAL FIELD The present invention relates to a heat insulating film having heat resistance capable of withstanding high heat from a high temperature heat source and heat insulating property to prevent heat transfer and to insulate, and a heat insulating coating composition for forming the same. Insulating paint composition suitable for a heat insulating structure of a floor tunnel in which an exhaust pipe is stored under the floor of a vehicle, etc., a heat insulating coating film comprising the heat insulating coating composition, and a vehicle floor panel and a vehicle using the heat insulating coating composition It relates to the floor tunnel structure.

  In a vehicle such as an automobile using an internal combustion engine (engine), a floor tunnel that opens to the lower side of the vehicle body is provided under the floor as a space for accommodating an exhaust pipe extending from the engine, as shown in FIG. An exhaust pipe is accommodated in the floor tunnel. Here, since the high temperature exhaust gas exhausted from the engine passes through the exhaust pipe, the periphery of the exhaust pipe is heated to a high temperature by the passage of the high temperature exhaust gas. Therefore, in the floor tunnel, in order to protect the parts around the floor panel and the exhaust pipe from the high heat of the exhaust pipe, conventionally, an insulator made of an aluminum extrusion-molded product or a press-molded product formed from an aluminum plate has been around the exhaust pipe. Installed on.

  For example, Patent Documents 1 to 3 cover the upper part of the exhaust pipe provided along the front-rear direction of the vehicle in a floor tunnel formed by bulging the floor panel upward at the center in the vehicle width direction. An insulator and a heat shield device are disclosed. Conventional insulators are usually attached to the floor panel below the floor panel using bolts, rivets, adhesives, or the like at a position away from the exhaust pipe serving as a heat source.

However, as disclosed in Patent Documents 1 to 3, conventionally, an insulator that covers an exhaust pipe disposed under the floor of a vehicle such as an automobile is disposed at a predetermined distance from the exhaust pipe and the floor panel. (See FIG. 6). In other words, the insulator needs to be disposed at a predetermined interval so as not to generate an interference sound with respect to the exhaust pipe that vibrates the exhaust, and the heat of the insulator whose temperature has been increased by the high heat from the exhaust pipe is not directly transmitted to the floor panel. The floor panel is also separated from the floor panel for a predetermined period.
For this reason, there is a problem that the space in the floor tunnel is restricted by the arrangement of the insulators, and the degree of freedom in designing the vehicle layout is restricted.

In particular, in recent years, miniaturization, weight reduction, and slimming of the vehicle body design have been promoted due to demands for low fuel consumption in vehicles such as automobiles, and there has been a request from users and others to expand the vehicle interior space. However, in the heat insulation structure using such an insulator, it is necessary to take a large space for arranging the insulator as described above, and thus it is difficult to save the floor tunnel.
In addition, in the heat insulation structure using an insulator, it is necessary to prevent the insulator from falling off due to vibration of the insulator. Therefore, the number of mounting parts for mounting the insulator on a floor panel or the like is large, and the number of assembly steps is also large, resulting in a problem of weight increase due to the mounting parts. There is also.
Furthermore, in a heat insulating structure using an insulator, there is a gap between the insulator and the floor panel. Depending on the running conditions of the vehicle, the hot air from the engine passes through the gap between the insulator and the floor panel. In addition, if there is such a gap, convection heat is generated there and the heat of the insulator is easily transferred to the floor panel. In addition, if there is a gap between the insulator and the floor panel, it tends to be disadvantageous for the aerodynamic performance of the vehicle that affects fuel consumption.

  Here, regarding the heat insulating structure around the exhaust pipe, in Patent Document 4, as a technique that can obtain a heat insulating effect without using a heat insulating material such as a heat shield plate or glass wool, containing an epoxy resin and a urethane resin, There is a proposal to apply a heat insulating paint containing a glass balloon treated with silane to the body panel.

JP2013-006503A JP 2002-362430 A JP 09-175198 A JP 2000-043758 A JP2009-208009A

However, since the heat insulating layer formed of the heat insulating paint described in Patent Document 4 is based on an epoxy resin and a urethane resin, the heat resistance is low. For this reason, even if this heat insulation layer is arranged alone around the exhaust pipe, it cannot function as a heat insulation layer under a high heat load.
Therefore, in Patent Document 4, a technique for forming a glitter layer by applying a glitter paint containing a volatile solvent and a thin aluminum glitter pigment that moves to the surface side as the solvent volatilizes on the heat insulating layer. Is disclosed.

  However, in such a heat insulation panel having a heat insulation layer and a glitter layer, it is necessary to prepare at least two kinds of paints, which requires troublesome work and also requires repeated coating. Cost. That is, the number of man-hours in the painting process and the drying process becomes great, and the man-hour for designing the paint becomes large, such as the need to prevent sagging during painting. Further, the cost becomes expensive. Patent Document 4 does not specifically disclose the paint composition, resin, or the like of the bright pigment of the bright layer, and the bright pigment does not fall off the coating film even if it is arranged around the exhaust pipe. The film properties of the glitter layer on whether the heat shielding performance of aluminum is exhibited is unclear, and it is unclear whether it exhibits a heat insulating effect over a long period of time even when arranged around the exhaust pipe.

  Patent Document 5 discloses a technique related to an insulator for a metal internal combustion engine that covers a part or all of an internal combustion engine mounted on a vehicle. However, a bubble or balloon-based filler is formed on the surface of a metal plate material constituting the insulator. There is a disclosure of an insulator for an internal combustion engine in which a layer of silicone rubber or silicone resin containing is formed.

  However, the technique of Patent Document 5 reduces the weight and improves the heat insulation of an insulator for an internal combustion engine by forming a silicone rubber or a silicone resin layer containing bubbles or a balloon-type filler with respect to the insulator for an internal combustion engine. The heat countermeasures around the internal combustion engine with a high thermal environment are disclosed, and as a heat countermeasure for the floor tunnel of the vehicle body in which the exhaust pipe extending from the internal combustion engine is disposed, it is arranged in the conventional floor tunnel. There is no disclosure of a technical idea that prevents heat from the exhaust pipe from being transferred to the floor panel by forming a heat insulating layer on the inner wall surface of the tunnel of the floor panel instead of the insulator. Further, there is no specific technical disclosure such as the composition of the silicone rubber or silicone resin layer paint formed on the surface of the insulator for the internal combustion engine, and in particular, the metal plate material constituting the insulator is aluminum with high thermal conductivity, Insulators placed around an internal combustion engine with a severe thermal environment, the temperature rise characteristics of a metal plate made of aluminum are high, and the silicone rubber or silicone resin has different thermal characteristics on the surface of such high thermal conductivity aluminum. Even if the layer is formed, it is predicted that the silicone rubber or the silicone resin layer is likely to fall off due to a high heat load due to heat conduction and a practical heat insulation effect cannot be obtained.

  Therefore, the present invention provides a heat insulating paint for a vehicle floor panel that has high heat resistance and heat insulating properties, enables space saving of the heat insulating structure around a high temperature heat source, and enables the formation of the heat insulating structure with high productivity. An object of the present invention is to provide a composition, a heat insulating coating, a vehicle floor panel, and a vehicle floor tunnel structure.

  The vehicle floor panel heat insulating coating composition of the invention of claim 1 contains a silicone resin and hollow particles, and the hollow particles are contained in an amount of 8.1 to 26.7 parts by weight with respect to 100 parts by weight of the silicone resin. And is applied to the surface of the floor panel of the vehicle, for example, in a floor tunnel under the floor opposite to the indoor space.

  The silicone resin is a synthetic resin material mainly composed of silicone having a main chain (inorganic) of siloxane bond and having an acid group in the side chain. Silicone paints such as rubber-like resins and acrylic silicone resins (Silicon paint) or the like can be used, but a rubber-like resin (silicone rubber) that becomes a rubber elastic body by curing is preferably used. In addition, in the case of liquid silicone rubber, it is preferable to use a two-liquid type from the viewpoint of handling handling and storage stability such as not requiring low-temperature storage, but a one-liquid type may be used. Furthermore, it may be a room temperature curing type that cures by reacting with moisture in the air at room temperature, a heat curing type that cures by heating, and may be either a condensation type or an addition type. From the viewpoint of forming a coating film having elasticity and flexibility that can follow the thermal expansion and contraction of a floor panel made of steel plate or the like, a thermosetting type and an addition type are preferable.

The hollow particles blended in the composition is a hollow body that maintains a predetermined hollowness even when the resin is heat-cured. For example, organic hollow particles having a shell (outer shell) made of a resin, a shell ( Inorganic hollow particles whose outer shell is made of inorganic materials such as glass, silica, shirasu, etc. can be used, but the thermoplastic resin microballoon is generally low in specific gravity and high in weight effect, and has a thick outer shell and high elasticity. (Extended resin microcapsules) are preferred. In addition, the hollow particle mix | blended with a composition means an already expanded thing if it is a balloon type | mold, and an unexpanded body, for example, the heat-expandable unexpanded microcapsule expand | swelled by heating is not contained.
And the said hollow particle is mix | blended within the range of 8.1 weight part or more and 26.7 weight part or less with respect to 100 weight part of said silicones, From a heat insulating viewpoint, More preferably, it is 10 From the viewpoint of coating workability, it is more preferably 25 parts by weight or less, and still more preferably 20 parts by weight or less.

  The silicone resin of the heat insulating paint composition for a vehicle floor panel according to the invention of claim 2 is an addition-type silicone resin, and the curing reaction proceeds by heating.

The hollow particles of the heat insulating paint composition for a vehicle floor panel according to the invention of claim 3 are resin microballoons.
The resin microballoon is a balloon in which a shell (outer shell) component is made of resin. For example, the resin microballoon includes a vaporized substance (hydrocarbon gas or the like) and the shell (outer shell) is made of a thermoplastic resin (for example, acrylonitrile). A hollow thermoplastic resin microballoon (pre-expanded microcapsule) obtained by thermally expanding the thermally expandable microcapsule is used. As this thermoplastic resin microballoon, a resin microballoon in which a shell (outer shell) made of a thermoplastic resin is coated with an inorganic powder such as calcium carbonate may be used.

The vehicle floor panel heat-insulating coating composition of the invention of claim 4 further contains thermally expandable microcapsules and / or a foaming agent.
The heat-expandable microcapsule is, for example, a heat-expandable unexpanded microcapsule containing a vaporized substance (for example, hydrocarbon gas) and having a shell (outer shell) made of a thermoplastic resin (for example, acrylonitrile). A hollow thermoplastic resin microballoon is formed by expansion by heat treatment after coating, for example, heating during curing of the coating film.
In addition, the foaming agent is preferably a heat treatment after coating, for example, heating during curing of the coating film to generate heat and generate gas to form bubbles in the coating film. An ADCA (azodicarbonamide) -based chemical foaming agent that is a heating type foaming agent is used.

According to a fifth aspect of the present invention, there is provided a heat insulating paint composition for a vehicle floor panel, wherein the thermally expandable microcapsule or the foaming agent is blended in an amount of 20 parts by weight or less with respect to 100 parts by weight of the silicone resin. It has been done. From the viewpoint of effective heat insulation improvement by the thermally expandable microcapsule or the foaming agent, the thermally expandable microcapsule or the foaming agent is more than 1 part by weight with respect to 100 parts by weight of the silicone resin. Preferably, from the viewpoint of achieving both high coating film strength and heat insulation, 15 parts by weight or less is more preferable.
Here, if the thermally expandable microcapsule or the foaming agent is a blend of only one of the thermally expandable microcapsule or the foaming agent with respect to 100 parts by weight of the silicone resin, It means that 20 parts by weight is the upper limit of the thermally expandable microcapsule or foaming agent. If it is a combined use of a thermally expandable microcapsule and a foaming agent, the upper limit of the total blending amount is preferably 25 parts by weight.

  The heat insulating coating film of the invention of claim 6 comprises hollow particles in a silicone resin and is formed on the surface of a vehicle floor panel, for example, formed in a floor tunnel under the floor opposite to the indoor space. It is.

  The silicone resin is a synthetic resin material mainly composed of silicone having a main chain (inorganic) of siloxane bond and having an acid group in the side chain. Silicone paints such as rubber-like resins and acrylic silicone resins (Silicon paint) or the like can be used, but a rubber-like resin (silicone rubber) that becomes a rubber elastic body by curing is preferably used. It may be a room temperature curing type cured by reacting with moisture in the air at room temperature, a heat curing type cured by heating, a condensation type or an addition type. From the viewpoint of forming a coating film having elasticity and flexibility that can follow the thermal expansion and contraction of the floor panel made of the like, a thermosetting type and an addition type are preferable.

  Examples of the hollow particles contained in the coating film include organic hollow particles whose shell (outer shell) is made of a resin, and inorganic hollow particles whose shell (outer shell) is made of an inorganic material such as glass, silica, and shirasu. In general, a thermoplastic resin microballoon (expanded resin microcapsule) having a small true specific gravity and a high light weight effect and having a thick outer shell and high elasticity is preferable. Note that the hollow particles contained in the coating film mean already expanded if it is a balloon type. However, the coating solution for forming the heat insulating coating film containing the hollow particles may be already expanded or unexpanded. It does not matter whether or not a mixture of the two is contained. If the coating solution for forming the heat-insulating coating contains an unexpanded one from the beginning, it expands with predetermined heating after coating. In the coating film, a hollow balloon is formed as a hollow particle.

  The silicone resin of the heat-insulating coating film of the invention of claim 7 is an addition-type silicone resin, and the curing reaction is advanced by heating with a curing catalyst such as platinum.

The said hollow particle of the heat insulation coating film of invention of Claim 8 is a resin microballoon.
The resin microballoon contained in the heat insulation coating is a balloon whose shell (outer shell) component is made of resin. For example, the shell (outer shell) contains a vaporized substance (hydrocarbon gas etc.) and the shell (outer shell) is thermoplastic. A hollow thermoplastic resin microballoon (an already expanded microcapsule) obtained by thermally expanding a thermally expandable microcapsule made of a resin (for example, acrylonitrile) is used. The thermoplastic resin microballoon may be a resin microballoon in which a shell (outer shell) made of a thermoplastic resin is coated with an inorganic powder such as calcium carbonate.

The heat-insulating coating film of the invention of claim 9 further comprises air bubbles in the silicone resin.
The bubbles may be formed by blending a foaming agent with a paint that forms a heat-insulating coating film and generating gas when the foaming agent is decomposed. It may be formed by the formation of bubbles by the introduction of air or the like in the film formation process, by stirring, or by swirling. Bubbles may be formed by using a self-foaming type liquid silicone or the like. In addition, “bubbles” are generally “a minute portion in a liquid or solid that contains a gas. (Shinmura, edited by “Kojien (4th edition)”, page 641, published by Iwanami Shoten Co., Ltd. on November 15, 1991). However, in the present specification and claims, it may or may not contain gas. Regardless, it shall be used to mean “a void in a liquid or solid”.

The heat insulating coating film of the invention of claim 10 has a thermal conductivity of 0.03 W / (m · K) or more and 0.08 W / (m · K) measured based on JIS A 1412-2 (heat flow meter method). ) Is the following.
According to the inventor's experimental research, in order to obtain a heat insulating property equal to or higher than that of a heat insulating structure using a conventional insulator, the thermal conductivity of the heat insulating coating is preferably 0.08 W / (m · K) or lower. From the viewpoint of heat insulation, the smaller the value, the better. However, the thermal conductivity of air is 0.026 W / (m · K), and the lower limit is 0.03 from the viewpoint of securing the coating strength. Is set. More preferably, it is 0.035 W / (m · K) or more and 0.06 W / (m · K) or less.

  The heat insulating coating film of the invention of claim 11 has a film thickness (dry film thickness) in the range of 0.1 mm to 30 mm, preferably 0.1 mm to 20 mm, more preferably 0.1 mm. It is within the range of -10 mm.

  A vehicle floor panel according to a twelfth aspect of the present invention includes, for example, an inner wall surface in a floor tunnel under a floor opposite to an indoor space with respect to a surface of a vehicle floor panel main body, and contains hollow particles in silicone resin. The heat insulation layer which becomes is formed.

  The silicone resin is a synthetic resin material mainly composed of silicone having a main chain (inorganic) of siloxane bond and having an acid group in the side chain. Silicone paints such as rubber-like resins and acrylic silicone resins (Silicon paint) or the like is used, but a rubber-like resin (silicone rubber) that becomes a rubber elastic body by curing is preferably used. It may be a room temperature curing type cured by reacting with moisture in the air at room temperature, a heat curing type cured by heating, a condensation type or an addition type. From the viewpoint of forming a coating film having elasticity and flexibility that can follow the thermal expansion and contraction of the floor panel made of the like, a thermosetting type and an addition type are preferable.

  Examples of the hollow particles contained in the heat insulating layer include organic hollow particles whose shell (outer shell) is made of resin, and inorganic hollow particles whose shell (outer shell) is made of an inorganic material such as glass, silica, and shirasu. In general, a thermoplastic resin microballoon (expanded resin microcapsule) having a small true specific gravity and a high light weight effect and having a thick outer shell and high elasticity is preferable. The hollow particles contained in the heat insulating layer mean already expanded if it is a balloon type. However, the raw material for forming the heat insulating layer containing the hollow particles may be an already expanded or unexpanded one. It does not matter whether or not a mixture of the two is contained, and if the raw material for forming the heat insulation layer contains an unexpanded one from the beginning, the heat insulation layer expands with a predetermined heating. The hollow balloon as a hollow particle.

  And the formation of the heat insulation layer may be formed, for example, by applying a predetermined coating solution to the surface of the floor panel body of the vehicle, or to form a heat insulation layer in the floor tunnel. A liquid material containing predetermined silicon resin and hollow particles may be poured to form a heat insulation layer on the floor panel surface, or the floor panel may be immersed in a liquid material containing predetermined silicon resin and hollow particles. A heat insulating layer may be formed on the floor panel surface, or a heat insulating layer can be formed by joining a molded product such as a sheet containing a predetermined silicon resin and hollow particles to the floor panel surface.

  The silicone resin of the heat insulation layer of the vehicle floor panel according to the invention of claim 13 is an addition type silicone resin, and a curing reaction is advanced by heating.

The hollow particles of the heat insulating layer of the vehicle floor panel of the invention of claim 14 are resin microballoons.
The resin microballoon contained in the heat insulation layer is a balloon whose shell (outer shell) component is made of a resin. For example, the shell (outer shell) contains a vaporized substance (hydrocarbon gas) and the shell (outer shell) is a thermoplastic resin. A hollow thermoplastic resin microballoon (an already expanded microcapsule) obtained by thermally expanding a thermally expandable microcapsule made of (for example, acrylonitrile) is used. The thermoplastic resin microballoon may be a resin microballoon in which a shell (outer shell) made of a thermoplastic resin is coated with an inorganic powder such as calcium carbonate.

The vehicle floor panel according to a fifteenth aspect of the present invention further includes bubbles in the silicone resin of the heat insulating layer.
The bubbles may be formed by blending a foaming agent with the raw material for forming the heat insulating layer and generating gas when the foaming agent is decomposed, or physical in the process of forming the raw material and the heat insulating layer. Alternatively, air bubbles may be generated by introducing air or the like, stirring, or swirling. Bubbles may be formed by using a self-foaming type liquid silicone or the like.

The heat insulating layer of the vehicle floor panel of the invention of claim 16 has a thermal conductivity measured based on JIS A 1412-2 (heat flow meter method) of 0.03 W / (m · K) or more and 0.08 W / (M · K) or less.
According to the inventor's experimental research, in order to obtain a heat insulating property equal to or higher than that of a heat insulating structure using a conventional insulator, the heat conductivity of the heat insulating layer is preferably 0.08 W / (m · K) or less, From the viewpoint of heat insulation, the smaller the value, the better. However, the thermal conductivity of air is 0.026 W / (m · K), and the lower limit is set to 0.03 from the viewpoint of securing strength. Is. More preferably, it is 0.035 W / (m · K) or more and 0.06 W / (m · K) or less.

  The heat insulation layer of the vehicle floor panel according to the invention of claim 17 has a thickness in the range of 0.1 mm to 30 mm, preferably in the range of 0.1 mm to 20 mm, more preferably in the range of 0.1 mm to 10 mm. Is.

  In the floor tunnel structure for a vehicle according to the eighteenth aspect of the present invention, an exhaust pipe is housed in a tunnel that is formed in a tunnel-like floor panel main body portion that protrudes toward the passenger compartment side on the upper side of the vehicle body and is formed below the vehicle body. A heat insulating layer made of silicone resin containing hollow particles is formed on the inner wall surface of the tunnel of the floor panel main body around the exhaust pipe.

The floor panel main body portion is formed in a tunnel shape by projecting toward the vehicle body upper side along the longitudinal direction of the vehicle body, and forms a floor tunnel that opens to the lower side of the vehicle body under the floor of the vehicle lower structure. It is.
The exhaust pipe extends from the engine and is housed in a tunnel that is formed in an opening on the lower side of the vehicle body by the protrusion of the floor panel main body portion to the upper side of the vehicle body.
Furthermore, the heat insulating layer is formed on the inner wall surface of the tunnel of the floor panel main body around the exhaust pipe, and contains hollow particles in silicone resin. It may be formed on the entire side wall surface and upper wall surface of the tunnel around the exhaust pipe, or may be partial on the side wall surface side or the upper wall surface side.

  Here, the silicone resin is a synthetic resin material mainly composed of silicone having a main chain (inorganic) of a siloxane bond and having an acid group in the side chain, such as a rubber-like resin or an acrylic silicone resin. A silicone resin (silicone paint) or the like is used, but a rubber-like resin (silicone rubber) that becomes a rubber elastic body by curing is preferably used. It may be a room temperature curing type cured by reacting with moisture in the air at room temperature, a heat curing type cured by heating, a condensation type or an addition type. From the viewpoint of forming a coating film having elasticity and flexibility that can follow the thermal expansion and contraction of the floor panel made of the like, a thermosetting type and an addition type are preferable.

  Examples of the hollow particles contained in the heat insulating layer include organic hollow particles whose shell (outer shell) is made of resin, and inorganic hollow particles whose shell (outer shell) is made of an inorganic material such as glass, silica, and shirasu. In general, a thermoplastic resin microballoon (expanded resin microcapsule) having a small true specific gravity and a high light weight effect and having a thick outer shell and high elasticity is preferable. The hollow particles contained in the heat insulating layer mean already expanded if it is a balloon type, but the original composition for forming the heat insulating layer containing the hollow particles is already expanded. It is not questioned whether or not an unexpanded material or a mixture of both was contained. If the composition forming the heat insulating layer contained an unexpanded material from the beginning, it was expanded by a predetermined heating. In the heat insulation layer, a hollow balloon is formed as a hollow particle.

  And the formation of the heat insulation layer may be formed, for example, by applying a predetermined coating solution to the surface of the floor panel body of the vehicle, or to form a heat insulation layer in the floor tunnel. A liquid material containing predetermined silicon resin and hollow particles may be poured to form a heat insulation layer on the floor panel surface, or the floor panel may be immersed in a liquid material containing predetermined silicon resin and hollow particles. A heat insulating layer may be formed on the floor panel surface, or a heat insulating layer can be formed by joining a molded product such as a sheet containing a predetermined silicon resin and hollow particles to the floor panel surface.

  The silicone resin of the heat insulating layer of the vehicle floor tunnel structure according to the invention of claim 19 is an addition-type silicone resin, and has undergone a curing reaction by heating.

The hollow particles of the heat insulating layer of the vehicle floor tunnel structure according to the twentieth aspect of the invention are resin microballoons.
The resin microballoon contained in the heat insulation layer is a balloon whose shell (outer shell) component is made of a resin. For example, the shell (outer shell) contains a vaporized substance (hydrocarbon gas) and the shell (outer shell) is a thermoplastic resin. A hollow thermoplastic resin microballoon (an already expanded microcapsule) obtained by thermally expanding a thermally expandable microcapsule made of (for example, acrylonitrile) is used. The thermoplastic resin microballoon may be a resin microballoon in which a shell (outer shell) made of a thermoplastic resin is coated with an inorganic powder such as calcium carbonate.

The vehicle floor tunnel structure of the invention of claim 21 further comprises bubbles in the silicone resin of the heat insulating layer.
The bubbles may be formed by blending a foaming agent with the raw material for forming the heat insulating layer and generating gas when the foaming agent is decomposed, or physical in the process of forming the raw material and the heat insulating layer. Alternatively, air bubbles may be generated by introducing air or the like, stirring, or swirling. Bubbles may be formed by using a self-foaming type liquid silicone or the like.

The heat insulating layer of the vehicle floor tunnel structure according to the invention of claim 22 has a thermal conductivity of 0.03 W / (m · K) or more, measured according to JIS A 1412-2 (heat flow meter method) It is less than or equal to 08 W / (m · K).
According to the inventor's experimental research, in order to obtain a heat insulating property equal to or higher than that of a heat insulating structure using a conventional insulator, the heat conductivity of the heat insulating layer is preferably 0.08 W / (m · K) or less, From the viewpoint of heat insulation, the smaller the value, the better. However, the thermal conductivity of air is 0.026 W / (m · K), and the lower limit is set to 0.03 from the viewpoint of securing strength. Is. More preferably, it is 0.035 W / (m · K) or more and 0.06 W / (m · K) or less.

  The heat insulation layer of the floor tunnel structure for a vehicle according to the invention of claim 23 has a thickness in the range of 0.1 mm to 30 mm, preferably in the range of 0.1 mm to 20 mm, more preferably in the range of 0.1 mm to 10 mm. It is what is.

The vehicle floor panel heat-insulating coating composition according to claim 1 contains a silicone resin and hollow particles, and the hollow particles are blended in an amount of 8.1 to 26.7 parts by weight with respect to 100 parts by weight of the silicone resin. It is a thing.
As a result of studying the heat insulation structure of the floor tunnel in order to increase the design flexibility of the floor tunnel in which the exhaust pipe can be stored under the floor of the vehicle, the present inventor has replaced the heat insulation structure using the conventional insulator with the silicone resin and the hollow. Insulation that is equal to or better than the conventional insulation structure using an insulator by applying a heat-insulating coating composition containing particles to the inner wall surface of the tunnel of the floor panel that forms the floor tunnel to form an insulating coating. In addition to ensuring heat resistance, unlike the conventional heat insulation structure with insulators, the heat insulation structure has less restrictions on the tunnel space, and it is possible to save space in the heat insulation structure and increase the design flexibility of the floor tunnel. The present invention has been completed based on this finding.

  That is, according to the heat insulating coating composition containing the silicone resin and the hollow particles, the silicone resin can ensure high heat resistance that can withstand high heat from the exhaust pipe, and also adheres to the surface of the floor panel made of steel plate or the like. In addition, a heat insulating coating film exhibiting a high heat insulating effect can be obtained by the low heat conductivity of the silicone resin and the heat insulating effect by the hollow particles.

Here, when the blending amount of the hollow particles is less than 8.1 parts by weight with respect to 100 parts by weight of the silicone resin, the thermal conductivity of the heat insulating coating is, for example, 0.08 W / (m · k) or less. It is difficult to obtain a high heat insulating property, and it is difficult to secure a heat insulating effect equivalent to that of a conventional heat insulating structure using an insulator and realize a space saving of the heat insulating structure. On the other hand, if the blending amount of the hollow particles exceeds 26.7 parts by weight with respect to 100 parts by weight of the silicone resin, viscosity and fluidity coating properties suitable for coating cannot be obtained, and coating workability cannot be ensured.
If the blending amount of the hollow particles is within a range of 8.1 parts by weight to 26.7 parts by weight with respect to 100 parts by weight of the silicone resin, the thermal conductivity is, for example, 0.08 W / (m · K). ) A heat insulating coating film having the following high heat insulating properties can be obtained, and the dry film thickness of the heat insulating coating film is, for example, a thin thickness of 30 mm or less, and a heat insulating property equal to or higher than that of a conventional heat insulating structure using an insulator. Can be secured, and space saving of the heat insulating structure is enabled.

  According to the heat insulating coating composition containing the silicone resin having such a predetermined composition and the hollow particles, the thermal conductivity is, for example, 0.08 W / () due to the low thermal conductivity of the silicone resin and the heat insulating effect of the hollow particles. m · K) The following heat insulating coating can be obtained, and because it has high heat resistance due to the silicone resin, even when the heat insulating coating is formed on the inner wall surface of the floor tunnel containing the exhaust pipe, Exhibits stable coating performance such as heat insulation without melting or thermal degradation. Furthermore, since the thermal conductivity of the heat insulating coating is low, the temperature rise of the coating itself can be suppressed, and even if a coating is formed on the inner wall surface of the floor panel forming the floor tunnel, the floor panel is not thermally deteriorated. Insulating high heat from the exhaust pipe, the temperature rise of the floor panel can be effectively suppressed. In the heat insulating structure in which a coating film is formed by applying a heat-insulating coating composition containing a predetermined amount of silicone resin and hollow particles to the tunnel inner wall surface of the floor panel, the coating film is brought into close contact with the floor panel. Unlike conventional heat insulation structures that use insulators, this is an arrangement that does not provide a gap between the floor panel, so it suppresses floor panel temperature rise due to direct convection and hot air from the engine. You can also. In addition, unlike a conventional heat insulating structure using an insulator, it is not necessary to provide an arrangement with a gap between the floor panel, and further, it is not necessary to provide a distance in consideration of interference noise with the exhaust pipe. It is possible to save the space of the heat insulation structure without being restricted by the tunnel space, and to increase the design flexibility of the floor tunnel.

  In particular, according to the heat insulating coating composition containing such a silicone resin and hollow particles, a heat insulating coating film having high heat insulating properties and high heat resistance can be formed on the surface of the floor panel only by applying one liquid. Since heat insulation equivalent to or better than the heat insulation structure used can be ensured, the number of paint design and painting man-hours can be reduced, and it is easy to form a floor tunnel heat insulation structure. That is, the heat insulation structure of the floor tunnel can be formed with high productivity.

  In this way, a heat-insulating coating film having high heat resistance and heat insulating properties can be formed, making it possible to save space in the heat insulating structure around a high-temperature heat source and to form a heat insulating structure with high productivity. It becomes the heat-insulating coating composition for vehicle floor panels.

  According to the heat insulating paint composition for a vehicle floor panel according to the invention of claim 2, since the silicone resin is an addition-type silicone resin, thermal expansion caused by a temperature change of a floor panel made of a steel plate to be applied, etc. A coating film having elasticity and flexibility that can follow the shrinkage can be formed. Therefore, in addition to the effect of Claim 1, the coating film is prevented from being cracked, cracked, wrinkled, etc., and a stable thermal insulation performance of the coating film can be obtained.

  According to the heat insulating paint composition for a vehicle floor panel according to the invention of claim 3, since the hollow particles are resin microballoons, in addition to the effects of claim 1 or claim 2, Light weight (low specific gravity) can be improved. In addition, the high resilience of the resin microballoons makes it difficult to be destroyed by shearing force at the time of preparing the paint, and makes it easy to control the heat insulation performance. In particular, the thermoplastic resin microballoon has excellent heat resistance, elasticity, and pressure resistance, and can increase the strength and flexibility of the coating film against pulling and bending of the coating film.

  According to the heat insulating paint composition for a vehicle floor panel according to the invention of claim 4, it further contains a thermally expandable microcapsule and / or a foaming agent, and therefore, according to any one of claims 1 to 3. In addition to the above effect, the heat insulation can be improved without deteriorating the coating workability.

  According to the heat insulating paint composition for a vehicle floor panel according to the invention of claim 5, the amount of the thermally expandable microcapsule and / or foaming agent is 20 parts by weight or less with respect to 100 parts by weight of the silicone resin. In addition to the effect described in claim 4, it is possible to improve the heat insulating property without deteriorating the film forming property.

According to the heat insulating coating film of the invention of claim 6, it is formed on the surface of the floor panel of the vehicle and contains hollow particles in the silicone resin.
As a result of studying the heat insulation structure of the floor tunnel in order to increase the design flexibility of the floor tunnel in which the exhaust pipe can be stored under the floor of the vehicle, the present inventor has replaced the heat insulation structure using the conventional insulator with a silicone resin and a heat insulation structure. A heat insulating structure in which a heat insulating coating composition containing a plastic resin microballoon or the like is applied to a tunnel inner wall surface of a floor panel forming a floor tunnel, and a heat insulating coating film containing silicone resin and hollow particles is formed on the floor panel surface; As a result, it is possible to ensure a thermal insulation equivalent to or better than the thermal insulation structure using a conventional insulator, and unlike the conventional thermal insulation structure where an insulator is arranged, the thermal insulation structure has less restrictions on the tunnel space, saving the thermal insulation structure. Based on this knowledge It is obtained by completing the present invention.

  That is, according to the heat insulating coating film comprising hollow particles in the silicone resin, the silicone resin can ensure high heat resistance that can withstand high heat from the exhaust pipe, and can adhere to the surface of the floor panel made of steel plate or the like. In addition, the low thermal conductivity of the silicone resin and the heat insulation effect by the hollow particles can exhibit a high heat insulation effect of, for example, a thermal conductivity of 0.08 W / (m · K) or less. In particular, since it has high heat resistance due to the silicone resin, even when a heat insulating coating is formed on the inner wall surface of the floor tunnel around the exhaust pipe, the heat insulating coating does not melt and heat deteriorate, and stable coating such as heat insulation can be achieved. Demonstrate membrane performance. Furthermore, since the thermal conductivity of the heat insulating coating is low, the temperature rise of the coating itself can be suppressed, and even if a coating is formed on the inner wall surface of the floor panel forming the floor tunnel, the floor panel is not thermally deteriorated. Insulating high heat from the exhaust pipe, the temperature rise of the floor panel can be effectively suppressed.

  And in the heat insulation structure which forms the heat insulation coating film which consists of a silicone resin and a hollow particle in the tunnel inner wall surface of a floor panel in this way, unlike the heat insulation structure using the conventional insulator, a clearance gap is not provided between floor panels. Because of the arrangement, it is possible to suppress the rise in the temperature of the floor panel due to direct convection and hot air from the engine. In addition, unlike a conventional heat insulating structure using an insulator, it is not necessary to provide an arrangement with a gap between the floor panel, and further, it is not necessary to provide a distance in consideration of interference noise with the exhaust pipe. It is possible to save the space of the heat insulation structure without being restricted by the tunnel space, and to increase the design flexibility of the floor tunnel.

  In particular, according to the heat insulating coating film comprising hollow particles in the silicone resin in this way, it has high heat insulating properties and heat resistance, which is equivalent to or better than the heat insulating structure using a conventional insulator only by the heat insulating coating film. Since heat insulation can be ensured and the number of man-hours for designing and painting the paint is small, it is easy to form a heat insulating structure for the floor tunnel. That is, the heat insulation structure of the floor tunnel can be formed with high productivity.

  In this way, it is possible to save the space of the heat insulation structure around the high-temperature heat source with high heat resistance and heat insulation, and it becomes a heat insulation coating film that can form the heat insulation structure with high productivity.

  According to the heat-insulating coating film according to the invention of claim 7, since the silicone resin is an addition-type silicone resin, the elasticity that can follow the thermal expansion and contraction caused by the temperature change of the floor panel made of a steel plate or the like to be coated. A film having flexibility can be formed. Therefore, in addition to the effect of Claim 6, the coating film is prevented from being cracked, cracked, wrinkled, and the like, and can exhibit the stable thermal insulation performance of the coating film.

  According to the heat insulating coating film of the invention of claim 8, since the hollow particles are resin microballoons, in addition to the effects of claim 6 or claim 7, the coating film is reduced in weight (low specific gravity). Can be improved. Moreover, it is hard to be destroyed by the high elasticity of the resin microballoon, and it can stably secure a predetermined porosity (hollowness) in the coating film and exhibit a stable heat insulating effect. Furthermore, control of heat insulation performance is facilitated. In particular, the thermoplastic resin microballoon has excellent heat resistance, elasticity, and pressure resistance, and can increase the strength and flexibility of the coating film against pulling and bending of the coating film.

  According to the heat insulating coating film of the invention of claim 9, since it further contains bubbles, in addition to the effect of any one of claims 6 to 8, the light weight effect can be enhanced.

  According to the heat insulating coating film of the invention of claim 10, the thermal conductivity thereof is in the range of 0.03 W / (m · K) to 0.08 W / (m · K). In addition to the effect described in any one of Items 9, for example, with a thin film thickness of 30 mm or less, while ensuring a predetermined coating film strength, a heat insulating property equivalent to or higher than that of a conventional heat insulating structure using an insulator is provided. It can be ensured, the temperature rise of the floor panel can be effectively suppressed, and the space-saving effect of the heat insulating structure is also high. Furthermore, since the desired heat insulation and strength can be ensured with a thin film thickness, the lightening effect is also high.

According to the heat insulating coating film of the invention of claim 11, the film thickness is in the range of 0.1 mm to 30 mm.
According to the inventor's experimental research, if the film thickness is too small, it is impossible to ensure the heat insulation equivalent to or better than the heat insulation structure using a conventional insulator. On the other hand, if the film thickness is too thick, the weight increases, Since it will take up space in the structure, and unevenness is likely to occur and the paintability and paint efficiency are also reduced, so that the preferred coating thickness is specified within the range of 0.1 mm to 30 mm It is. And according to the heat insulating coating film containing hollow particles in the silicone resin, with such a thin film, it is possible to secure a heat insulating property equal to or better than a heat insulating structure using a conventional insulator, and to save space of the heat insulating structure. To do.
Thus, if the film thickness of the heat insulating coating is within the range of 0.1 mm to 30 mm, in addition to the effect of any one of claims 6 to 10, good applicability can be secured. It is excellent in light weight and has very few restrictions on tunnel space.

According to the vehicle floor panel of the twelfth aspect of the present invention, a heat insulating layer made of silicone resin containing hollow particles is formed on the surface of the vehicle floor panel main body.
As a result of studying the heat insulation structure of the floor tunnel in order to increase the design flexibility of the floor tunnel in which the exhaust pipe can be stored under the floor of the vehicle, the present inventor has replaced the heat insulation structure using the conventional insulator with a silicone resin and a heat insulation structure. A thermal insulation coating composition containing a silicone resin and hollow particles is formed on the floor panel surface by applying a thermal insulation coating composition containing a plastic resin microballoon or the like to the inner wall surface of the floor panel tunnel. The heat insulation structure can ensure heat insulation equivalent to or better than the heat insulation structure using conventional insulators, and unlike the heat insulation structure where conventional insulators are arranged, the heat insulation structure has less restrictions on the tunnel space and has a heat insulation structure. And found that floor tunnel design flexibility can be increased. In which the present invention has been completed based on the finding.

  That is, according to the heat insulating layer containing hollow particles in the silicone resin, high heat resistance that can withstand high heat from the exhaust pipe can be secured by the silicone resin, and adhesion to the surface of the floor panel made of steel plate or the like can be secured. Adhesiveness is also good, and due to the low thermal conductivity of the silicone resin and the heat insulation by the hollow particles, for example, a high heat insulation effect with a thermal conductivity of 0.08 W / (m · K) or less can be exhibited. In particular, because it has high heat resistance due to silicone resin, even when a heat insulating layer is formed on the inner wall surface of the floor tunnel around the exhaust pipe, the heat insulating layer does not melt and heat deteriorate, and exhibits stable characteristics such as heat insulating properties. To do. Furthermore, since the heat conductivity of the heat insulating layer is low, the temperature rise of the heat insulating layer itself can be suppressed, so that even if a heat insulating layer is formed on the inner wall surface of the tunnel of the floor panel forming the floor tunnel, the floor panel is not thermally deteriorated. Insulating high heat from the exhaust pipe, the temperature rise of the floor panel can be effectively suppressed.

  And in the heat insulation structure which forms the heat insulation layer which consists of a silicone resin and a hollow particle in the tunnel inner wall surface of a floor panel in this way, unlike the heat insulation structure using the conventional insulator, arrangement | positioning which does not provide a clearance gap between floor panels Therefore, it is possible to suppress the temperature rise of the floor panel due to direct convection and hot air from the engine. In addition, unlike a conventional heat insulating structure using an insulator, it is not necessary to provide an arrangement with a gap between the floor panel, and further, it is not necessary to provide a distance in consideration of interference noise with the exhaust pipe. It is possible to save the space of the heat insulation structure without being restricted by the tunnel space, and to increase the design flexibility of the floor tunnel.

  In particular, according to the heat insulating layer comprising hollow particles in the silicone resin in this way, it has high heat insulating properties and heat resistance, and only the heat insulating layer has a heat insulating property equal to or better than a heat insulating structure using a conventional insulator. Therefore, it is easy to form the heat insulating structure of the floor tunnel because the design man-hour for forming the heat insulating structure can be reduced. That is, the heat insulation structure of the floor tunnel can be formed with high productivity.

  In this way, the heat insulation layer having high heat resistance and heat insulation enables space-saving of the heat insulation structure around the high-temperature heat source, and the vehicle floor panel enables the formation of the heat insulation structure with high productivity. Become.

  According to the vehicle floor panel of the invention of claim 13, since the silicone resin of the heat insulating layer is an addition type silicone resin, it can follow thermal expansion and contraction caused by a temperature change of the floor panel made of a steel plate or the like. It has elasticity and flexibility. Therefore, in addition to the effect of Claim 12, a crack, a crack, a flaw, etc. are prevented in the heat insulation layer, and the stable heat insulation performance can be obtained.

  According to the vehicle floor panel of the fourteenth aspect of the invention, since the hollow particles of the heat insulating layer are resin microballoons, in addition to the effects of the twelfth or thirteenth aspect, the light weight of the heat insulating layer. (Improvement in specific gravity) can be improved. Moreover, it is hard to be destroyed by the high elasticity of the resin microballoon, and it can stably secure a predetermined porosity (hollowness) in the heat insulating layer and exhibit a stable heat insulating effect. Furthermore, control of heat insulation performance is facilitated. In particular, the thermoplastic resin microballoon is excellent in heat resistance, elasticity, and pressure resistance, and it is also possible to increase the strength of the heat insulation layer against pulling or bending.

  According to the vehicle floor panel of the fifteenth aspect of the present invention, since the heat insulating layer further contains bubbles, in addition to the effect of any one of the twelfth to fourteenth aspects, the light weight effect is enhanced. be able to.

  According to the vehicle floor panel according to the invention of claim 16, the thermal conductivity of the heat insulating layer is in the range of 0.03 W / (m · K) to 0.08 W / (m · K). In addition to the effect described in any one of claims 12 to 15, for example, a heat insulating layer having a thin thickness of 30 mm or less and a heat insulating structure using a conventional insulator while ensuring a predetermined strength The same or better heat insulation can be secured, the temperature rise of the floor panel can be effectively suppressed, and the space-saving effect of the heat insulation structure is also high. Furthermore, since the desired heat insulation and strength can be ensured with a thin thickness of the heat insulating layer, the effect of reducing the weight is also high.

According to the vehicle floor panel of the invention of claim 17, the thickness of the heat insulating layer is in the range of 0.1 mm to 30 mm.
According to the present inventors' research, if the thickness of the heat insulating layer is too thin, it is impossible to ensure the same or better heat insulating property as the heat insulating structure using a conventional insulator, while if the heat insulating layer is too thick, the weight Since it becomes heavier and also takes up space for the heat insulating structure, the preferred thickness of the heat insulating layer is specified within the range of 0.1 mm to 30 mm. And, according to the heat insulation layer containing hollow particles in the silicone resin, it is possible to save the space of the heat insulation structure with such a thin thickness, ensuring heat insulation equivalent to or better than the heat insulation structure using a conventional insulator. And
Thus, if the thickness of the heat insulating layer is in the range of 0.1 mm to 30 mm, in addition to the effect according to any one of claims 12 to 16, good applicability can be secured, It is excellent in lightness and has very few restrictions on tunnel space.

  According to the vehicle floor tunnel structure of the eighteenth aspect of the present invention, the vehicle extends from the engine into the tunnel of the floor panel main body portion that protrudes toward the passenger compartment side above the vehicle body along the longitudinal direction of the vehicle body and has a tunnel shape. An exhaust pipe is accommodated, and a heat insulating layer made of silicone resin containing hollow particles is formed on the inner wall surface of the tunnel of the floor panel body around the exhaust pipe.

  As a result of studying the heat insulation structure of the floor tunnel in order to increase the design flexibility of the floor tunnel in which the exhaust pipe can be stored under the floor of the vehicle, the present inventor has replaced the heat insulation structure using the conventional insulator with a silicone resin and a heat insulation structure. A thermal insulation coating composition containing a silicone resin and hollow particles is formed on the floor panel surface by applying a thermal insulation coating composition containing a plastic resin microballoon or the like to the inner wall surface of the floor panel tunnel. The heat insulation structure can ensure heat insulation equivalent to or better than the heat insulation structure using conventional insulators, and unlike the heat insulation structure where conventional insulators are arranged, the heat insulation structure has less restrictions on the tunnel space and has a heat insulation structure. And found that floor tunnel design flexibility can be increased. In which the present invention has been completed based on the finding.

  That is, according to the heat insulation layer containing hollow particles in the silicone resin formed on the inner wall surface of the tunnel of the floor panel main body, it is possible to ensure high heat resistance that can withstand high heat from the exhaust pipe by the silicone resin, Adhesion and adhesion to the surface of the floor panel made of steel plate and the like are good, and the thermal conductivity of the silicone resin and the heat insulation by the hollow particles, for example, the thermal conductivity is 0.08 W / (m · K) or less High heat insulation effect can be demonstrated. In particular, because it has high heat resistance due to silicone resin, even when a heat insulating layer is formed on the inner wall surface of the floor tunnel around the exhaust pipe, the heat insulating layer does not melt and heat deteriorate, and exhibits stable characteristics such as heat insulating properties. To do. Furthermore, since the heat conductivity of the heat insulating layer is low, the temperature rise of the heat insulating layer itself can be suppressed, so that even if a heat insulating layer is formed on the inner wall surface of the tunnel of the floor panel forming the floor tunnel, the floor panel is not thermally deteriorated. Insulating high heat from the exhaust pipe, the temperature rise of the floor panel can be effectively suppressed.

  And in the floor tunnel structure which forms the heat insulation layer which consists of a silicone resin and a hollow particle in the tunnel inner wall surface of a floor panel in this way, unlike the heat insulation structure using the conventional insulator, a clearance gap is not provided between floor panels. Because of the arrangement, it is possible to suppress the rise in the temperature of the floor panel due to direct convection and hot air from the engine. In addition, unlike a conventional heat insulating structure using an insulator, it is not necessary to provide an arrangement with a gap between the floor panel, and further, it is not necessary to provide a distance in consideration of interference noise with the exhaust pipe. It is possible to save the space of the heat insulation structure without being restricted by the tunnel space, and to increase the design flexibility of the floor tunnel.

  In particular, according to the heat insulating layer comprising hollow particles in the silicone resin in this way, it has high heat insulating properties and heat resistance, and only the heat insulating layer has a heat insulating property equal to or better than a heat insulating structure using a conventional insulator. Therefore, it is easy to form the heat insulating structure of the floor tunnel because the design man-hour for forming the heat insulating structure can be reduced. That is, the heat insulation structure of the floor tunnel can be formed with high productivity.

  In this way, the heat insulating layer having high heat resistance and heat insulating property can reduce the space of the heat insulating structure around the high temperature heat source, and the floor tunnel structure can form the heat insulating structure with high productivity.

  According to the vehicle floor tunnel structure of the nineteenth aspect of the invention, since the silicone resin of the heat insulating layer is an addition-type silicone resin, it is caused by a temperature change of a floor panel main body portion made of a steel plate to be coated. It has elasticity and flexibility that can follow thermal expansion and contraction. Therefore, in addition to the effect of Claim 18, a crack, a crack, a flaw, etc. are prevented in the heat insulation layer, and the stable heat insulation performance can be obtained.

  According to the vehicle floor tunnel structure of the invention of claim 20, since the hollow particles of the heat insulation layer are resin microballoons, in addition to the effects of claim 18 or claim 19, It is possible to improve the weight reduction (low specific gravity). Moreover, it is hard to be destroyed by the high elasticity of the resin microballoon, and it can stably secure a predetermined porosity (hollowness) in the heat insulating layer and exhibit a stable heat insulating effect. Furthermore, control of heat insulation performance is facilitated. In particular, the thermoplastic resin microballoon is excellent in heat resistance, elasticity, and pressure resistance, and it is also possible to increase the strength of the heat insulation layer against pulling or bending.

  According to the floor tunnel structure for a vehicle according to the invention of claim 21, since the heat insulating layer further contains bubbles, in addition to the effect of any one of claims 18 to 20, a light weight effect. Can be increased.

  According to the vehicle floor tunnel structure of the invention of claim 22, the thermal conductivity of the heat insulating layer is in the range of 0.03 W / (m · K) to 0.08 W / (m · K). In addition to the effect described in any one of claims 18 to 21, for example, a heat insulating layer having a thin thickness of 30 mm or less and a heat insulating structure using a conventional insulator while ensuring a predetermined strength The same or better heat insulation can be secured, the temperature rise of the floor panel can be effectively suppressed, and the space-saving effect of the heat insulation structure is also high. Furthermore, since a desired heat insulating property and strength can be ensured with a thin thickness of the heat insulating layer, the light weight effect is also high.

According to the vehicle floor tunnel structure of the twenty-third aspect of the present invention, the thickness of the heat insulating layer is in the range of 0.1 mm to 30 mm.
According to the present inventors' research, if the thickness of the heat insulating layer is too thin, it is impossible to ensure the same or better heat insulating property as the heat insulating structure using a conventional insulator, while if the heat insulating layer is too thick, the weight Since it becomes heavier and also takes up space for the heat insulating structure, the preferred thickness of the heat insulating layer is specified within the range of 0.1 mm to 30 mm. And, according to the heat insulation layer containing hollow particles in the silicone resin, it is possible to save the space of the heat insulation structure with such a thin thickness, ensuring heat insulation equivalent to or better than the heat insulation structure using a conventional insulator. And
Thus, if the thickness of the heat insulating layer is in the range of 0.1 mm to 30 mm, in addition to the effect of any one of claims 18 to 22, good applicability can be secured, It is excellent in lightness and has very few restrictions on tunnel space.

FIG. 1 is a bottom view showing an underfloor structure under a vehicle to which a heat insulating coating composition, a heat insulating coating, a floor panel, and a floor tunnel structure according to an embodiment of the present invention are applied. FIG. 2 is a cross-sectional view of a vehicle floor tunnel structure to which a heat insulating coating composition, a heat insulating coating, and a floor panel according to an embodiment of the present invention are applied. FIG. 3A is a conceptual diagram illustrating an example in which thermally expandable microcapsules are blended in addition to the blending of the silicone resin and the hollow particles in the heat insulating coating composition according to the embodiment of the present invention, and FIG. ) Is a conceptual diagram illustrating an example in which a foaming agent is blended in addition to the blending of the silicone resin and the hollow particles in the heat insulating coating composition according to the embodiment of the present invention. FIG. 4 evaluated the heat insulating properties of the heat insulating coatings formed from the heat insulating coating compositions according to Examples 1 to 3 of the embodiment of the present invention in comparison with Comparative Example 1. It is explanatory drawing for demonstrating the evaluation method. FIG. 5 shows an evaluation of the heat insulating property of the heat insulating coating film formed from the heat insulating coating composition according to Example 1 of the embodiment of the present invention, as compared with a heat insulating structure using a conventional insulator. It is explanatory drawing for demonstrating the evaluation method, (a) is sectional drawing explaining the heat insulation structure using the heat insulation layer which consists of heat insulation coating films, (b) Explaining the heat insulation structure using an insulator. It is sectional drawing. FIG. 6 is a cross-sectional view of a vehicle floor tunnel structure for explaining a heat insulation structure using a conventional insulator.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that, in the embodiment, the same symbols and the same reference numerals are functional parts common to the embodiments, and thus detailed description thereof is omitted here.

  The heat insulating coating composition according to the embodiment of the present invention includes a silicone resin and hollow particles. For example, as shown in FIGS. 1 and 2, the exhaust pipe 30 is disposed under the floor of a vehicle such as an automobile 1. Is applied to the inner wall surface of the tunnel of the floor panel main body 21 that forms the floor tunnel 40 in which the floor tunnel 40 is stored, thereby forming a heat insulating coating film that becomes the heat insulating layer 10 on the surface of the floor panel main body 21 to insulate the floor tunnel 40. It constitutes the structure.

  Here, the rubber-like thing (silicone rubber) which becomes a rubber elastic body by hardening is suitably used for the silicone resin. Either an addition type or a condensation type may be used, but if it is an addition type, it is elastic and flexible so that it can follow the thermal expansion and contraction caused by the temperature change of the floor panel body 21 made of a steel plate to be coated. It is easy to obtain a coating film having properties. Further, addition-type silicone resins are preferable from the viewpoints of curing speed and productivity, and film formation from which shrinkage due to curing does not occur.

  The addition-type silicone resin is, for example, a silicone polymer having a vinyl group such as an organopolysiloxane containing at least two carbon-carbon double bonds reactive with at least SiH group in one molecule, and one molecule. A silicon polymer having an H group such as an organohydrogenpolysiloxane containing at least two SiH groups therein and an addition reaction catalyst such as a platinum catalyst (platinum compound), and by carrying out a hydrosilylation reaction by heating, Si It becomes a compound having a —C—C—Si bond at the cross-linking point, and is cured by a hydrosilylation reaction.

  In addition, the silicone resin is usually used in a liquid state at normal temperature, and either a one-component type or a two-component type may be used. However, storage handling properties and storage stability such as low temperature storage are not required. The two-component type is preferably used.

  As the hollow particles to be mixed with the silicone resin, even when heating is performed in order to cure the resin after coating, it is sufficient if the predetermined hollowness is maintained without being expanded and ruptured by the heating. For example, inorganic hollow particles (inorganic micro hollow bodies) in which the outer shell of a shirasu balloon or the like formed by baking and foaming glassy volcanic debris such as borosilicate silica balloons, glass balloons, shirasu, etc. , Synthetic resins (plastics) such as thermoplastic resin microballoons and phenolic balloons such as pre-expanded resin microcapsules (thermally expandable microspheres) made of vinylidene chloride, acrylonitrile, polyvinylidene chloride, or copolymers thereof Organic hollow particles in which the outer shell of resin microballoons or carbon hollow spheres is organically formed There will be used. One of these may be used alone, or two or more may be used in appropriate combination.

The hollow particles have an average diameter (median diameter) of preferably 10 μm or more and 300 μm or less, more preferably 20 μm or more and 200 μm or less. With such a size, uniform dispersion is possible, coating workability is good, and coating unevenness can be reduced.
In addition, according to the definitions of terms in the text and explanation of JIS Z 8901 “Test Powder and Test Particles”, “median diameter” means the number larger than a certain particle diameter ( or mass), the particle diameter when occupying 50% of its Zenkonatai (diameter), i.e., a particle size of oversized 50%, represented generally with median diameter or 50% particle size and good D ₅₀ It is. By definition, the size of the particle group is expressed by the median diameter and the average particle diameter, but if it is close to the normal distribution, the difference from the average particle diameter (average value of contained particles) in catalog display etc. is also small. Yes, it can be considered that the median diameter is equal to the average particle diameter and the median diameter is equal to the average particle diameter. In general, in catalog display, the cumulative 50% particle diameter is sometimes referred to as the average particle diameter. Here, it is a value measured by the display of the product description and the laser diffraction / scattering method. The “median diameter measured by the laser diffraction / scattering method” means a particle diameter (the cumulative weight part of which is 50% in the particle size distribution obtained by the laser diffraction / scattering method using a laser diffraction particle size distribution measuring device). It refers to D _50). Note that the above numerical values are not strict and are approximate values, and are naturally approximate values including errors due to measurement or the like, and do not deny errors of several percent.

  The hollow particle contained in the composition is preferably a thermoplastic resin called a pre-expanded microcapsule in which a heat-expandable microphone capsule in which a low-boiling point hydrocarbon or the like is wrapped with a thermoplastic resin is expanded by heating. It is a microballoon. Since such a resin balloon has a small true specific gravity, the effect of reducing the weight (reducing specific gravity) of the coating film is high.

  This thermoplastic resin microballoon, also called an expanded microcapsule, is made of, for example, a thermoplastic resin constituting a shell inside a shell (shell wall, outer shell) made of a thermoplastic resin such as acrylonitrile. By heating a microcapsule having a structure in which a vaporizing substance having a boiling point lower than the softening temperature (for example, low boiling point hydrocarbon) is enclosed, the shell is softened by heating the microcapsule to a temperature higher than the softening temperature of the shell. The encapsulated vaporized substance is changed into a gas, and the capsule is expanded by increasing the pressure (expansion force / vapor pressure) of the gas, and the shell is a hollow microballoon made of a thermoplastic resin.

  The thermoplastic resin constituting the shell of the thermoplastic resin microballoon includes, for example, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylonitrile vinylidene chloride copolymer, acrylonitrile methyl methacrylate copolymer, acrylamide, acrylic Examples include acid, acrylic acid ester, methacrylamide, methacrylic acid, methacrylic acid ester, vinyl acetate, vinylidene chloride-acrylonitrile copolymer, acrylonitrile methacrylic acid, and methyl copolymer.

  The shell of the thermoplastic resin microballoon is mainly composed of the above-described thermoplastic resin, but may contain other components, and the manufacturing method of the thermoplastic resin microballoon is not particularly limited. Commercially available products (for example, Matsumoto Microsphere (registered trademark) F-DE series, MFL series manufactured by Matsumoto Yushi Seiyaku Co., Ltd., and Expandel (registered trademark) expanded grade manufactured by Nippon Ferrite Co., Ltd.) Can be obtained and used, or can be produced by a conventionally known method and used. For example, radically polymerizable monomers such as acrylonitrile and vinyl chloride, and any crosslinking agent (eg, divinylbenzene, (poly) ethylene glycol (di) methacrylate, triallyl isocyanurate (TAIC), trimethylolpropane trimethacrylate) (TMP, triacryl formal (TAF), etc.) and a mixture obtained by mixing a monomer mixture containing a polymerization initiator and a foaming agent (organic solvent), an aqueous system containing an appropriate dispersion stabilizer, etc. It is also possible to use a heat-expandable microcapsule produced by suspension polymerization in a suspension and heated and expanded at a predetermined temperature.

  As described above, such a thermoplastic resin microballoon has a high light-weight effect, and has high heat resistance from the thickness of the shell and the properties of the thermoplastic resin, and has high elasticity and high pressure resistance. . In particular, a hybrid balloon in which inorganic powder is adhered to the surface of a shell made of a thermoplastic resin. Specifically, the shell thermoplastic resin is coated with an inorganic metal salt or a metal oxide such as calcium carbonate, talc, titanium oxide or the like. Balloons are excellent in elasticity and are not easily destroyed by shearing force, stirring stress, etc. during preparation of paints that mix materials, pumping during application, and discharge pressure during application. The predetermined porosity can be easily controlled, the miscibility with the silicone resin is good and uniform dispersion is possible, and the strength and flexibility of the coating film against pulling and bending are enhanced.

  Such thermoplastic resin microballoons preferably have an average particle diameter (median diameter) of 20 μm or more and 200 μm or less, more preferably 30 μm or more and 150 μm or less. If it is such a size, it is excellent in uniform dispersibility, coating workability, and coating property, as well as good adhesion and adhesion of the coating film to the coated surface, and has a desired pressure strength and breakage The strength of the coating film is also good. In particular, as will be described later, in the floor tunnel 40 under the vehicle body floor of the automobile 1 shown in FIGS. 1 and 2, when the high adhesion of the coating film is obtained with respect to the floor panel main body portion 21 serving as the application surface, the floor panel main body is obtained. Since hot air can be prevented from entering the gap between the portions 21, a heat insulating structure that can effectively prevent the temperature rise of the floor panel body 21 can be formed.

  The heat insulating coating composition of the present embodiment containing such a silicone resin and hollow particles is prepared by using a known mixing and dispersing machine such as a planetary mixer, a Glen mill, a kneader, an attritor, a roll, or a dissolver. It is prepared by mixing and stirring uniformly. Then, the coating part is coated by a conventionally known coating method such as airless spray coating, air spray coating, brush coating, roller coating, dip coating, etc., for example, from the high heat of the exhaust pipe 30 as shown in FIGS. It is painted on the surface of the floor panel body 21 under the vehicle body floor where the temperature rise is to be protected.

  Here, when the silicone resin of the heat insulating coating composition of the present embodiment is an addition-type silicone resin, a predetermined surface of a painted surface, for example, a floor panel body 21 constituting the floor tunnel 40 as shown in FIG. After the coating on the part, the silicone resin is thermally cured by a heat treatment such as baking and drying, whereby a heat insulating coating (curing) as a heat insulating layer 10 is applied on the painted surface, for example, the surface of the floor panel main body 21 shown in FIG. Coating film) can be formed. In particular, addition-type silicone resins provide fast coating curing speeds, and are resistant to cracking and swelling due to curing without shrinkage or gas generation. Excellent stability of coating film properties.

In such a heat-insulating coating composition containing an addition-type silicone resin and hollow particles, after being applied to a predetermined site, for example, it is cured by baking at a temperature of 120 ° C. to 160 ° C. for 20 to 40 minutes. Thus, a cured heat insulating coating film is formed. In particular, as shown in FIGS. 1 and 2, for example, as shown in FIGS. 1 and 2, the heat-insulating coating composition of the present embodiment has a surface of a floor panel main body portion 21 made of a steel plate or the like that forms a floor tunnel 40 under the floor of the vehicle body of the automobile 1. Specifically, since the coating is applied to the inner wall surface of the tunnel of the protruding portion 21a of the floor panel main body portion 21 shown in FIG. 2, for example, the degreasing step, the chemical conversion treatment step, and the undercoating step by electrodeposition coating are finished. These are applied to the electrodeposition coating surface of the floor panel body 21 made of steel plate and the like, in addition to baking drying in a coating drying furnace such as intermediate coating or top coating finishing coating other than the protruding portion 21a. It is also possible to heat and cure at the same time. In other words, it is possible to obtain a heat-insulating coating by curing at the heat treatment temperature (usually within the range of 120 ° C to 160 ° C) during baking and drying of the intermediate coating or outer coating used in the current automobile coating line. It is. Of course, the intermediate coating and the finish coating may be baked separately by heat treatment.
In the case of a condensation type silicone resin, a cured coating film can be formed by film formation even at room temperature drying.

  Thus, according to the heat insulating paint composition of the present embodiment, since it contains a silicone resin and hollow particles, it is applied to the painted surface such as the surface of the floor panel body portion 21 made of a steel plate or the like by the base material silicone resin. Adhesion is good, and the adhesion rate when applied to the painted surface can be ensured to be 80% or more, for example, and the adhesiveness and adhesion to the painted surface are good even after curing. The base silicone resin 11 has a high heat resistance that can withstand a high temperature heat source, for example, the high temperature from the exhaust pipe 30 shown in FIGS. 1 and 2, and the high temperature heat source such as the exhaust pipe 30. A heat insulating coating film that retains the hollow particles 12 without being thermally deteriorated or melted even if arranged around the periphery and exhibits high heat insulating properties due to the low thermal conductivity of the silicone resin 11 and the heat insulating properties due to the voids of the hollow particles 12 is obtained. Furthermore, the coating film weight (dry coating film specific gravity) is small by inclusion of the hollow particles 12, and it is also lightweight.

According to the heat insulating coating composition containing such a silicone resin and hollow particles, the heat insulating coating film having a low thermal conductivity of, for example, a thermal conductivity of 0.08 W / (m · k) or less with a predetermined composition. For example, even with a thin film thickness (dry film thickness) of 30 mm or less, a high heat insulating effect equivalent to or higher than that of a conventional floor tunnel heat insulating structure using an insulator can be exhibited.
In particular, according to hollow particles such as thermoplastic resin microballoons, for example, temperature rising conditions, coating locations, and coating amounts when applied to the floor panel body 21 shown in FIGS. 1 and 2 to form a cured coating film Because the hollowness is not easily affected by coating conditions such as coating viscosity and other conditions such as the viscosity of the coating film, it is easy to control the predetermined porosity in the heat-insulating coating, and stable heat insulation and lightweight due to the voids of the hollow particles stably The desired heat insulation performance and the coating weight can be easily controlled. Furthermore, with hollow particles, it is difficult to be affected by conditions such as coating conditions, temperature rise conditions, and coating film viscosity, so it is easy to control heat insulation not only by the amount of addition, but also by adjusting the particle size distribution and particle size. Can be. Therefore, it is possible to easily control the film thickness and coating film characteristics of the heat insulating coating film.

  Thus, the heat insulating coating film obtained from the heat insulating coating composition of the present embodiment is excellent in heat resistance because the silicone resin 11 is used as a base material, and further has a low crosslinking density and contains an organic component. According to the above, it is excellent in adhesion and adhesion to the painted surface of the floor panel body 21 made of steel plate, etc., and it ensures excellent adhesion and adhesion to the painted surface even after curing by simply applying to the painted site. it can. Even if it is a part having a curved surface or a complicated surface shape, construction to follow it is easy. Moreover, since the silicone resin 11 has a low thermal conductivity and the hollow particles 12 are contained in the silicone resin 11, it has excellent heat insulation properties. Therefore, for example, it is effective for heat insulation measures for the floor tunnel 40 in which the exhaust pipe 30 that is considerably hot because the high-temperature exhaust gas from the engine shown in FIG. 1 circulates.

  That is, as shown in FIG. 2, the heat insulating coating composition containing such a silicone resin and hollow particles is applied to the inner wall surface side of the tunnel at the protruding portion 21a of the floor panel main body portion 21, and cured to obtain a silicone resin. By forming a heat insulating coating film as the heat insulating layer 10 composed of 11 and hollow particles 12, the thermal conductivity of the coating film is reduced to 0. 0 by the low heat conductivity of the silicone resin 11 and the heat insulating property by the hollow particles 12. High heat insulation effect of 08 W / (m · k) or less is exhibited, and only one liquid (one layer) application of the heat insulation coating composition is performed, and the heat insulation effect equivalent to or better than the heat insulation structure using a conventional insulator, that is, floor The effect which suppresses effectively the temperature rise of the panel main-body part 21 is acquired. And according to the heat insulation structure which forms the heat insulation coating as the heat insulation layer 10 by apply | coating the heat insulation coating composition containing a silicone resin and a hollow particle in this way to the tunnel inner wall surface of the floor panel main-body part 21 in the floor tunnel 40. For example, unlike the heat insulating structure in which the conventional insulator shown in FIG. 6 is arranged, there is no restriction to provide a predetermined wide space and space between the floor panel main body 21 and the exhaust pipe 30, thereby reducing the space of the heat insulating structure. Is possible.

Here, the heat insulating structure of the floor tunnel 40 configured using the heat insulating coating composition of the present embodiment will be described in detail with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, in an automobile 1 having an internal combustion engine (engine), an exhaust pipe 30 is connected from an engine (not shown) through an exhaust manifold (not shown) under the floor of the vehicle body. The exhaust pipe 30 is housed in a tunnel opening 41 of a floor tunnel 40 formed in a tunnel shape under the floor by projecting the floor panel 20 (floor panel body 21) of the vehicle body toward the upper compartment. . As shown in FIG. 1, the floor tunnel 40 and the exhaust pipe 30 accommodated therein extend along the longitudinal direction of the vehicle body, and the floor tunnel 40 and the exhaust pipe 30 therein are Usually, it is arrange | positioned in the center part of the vehicle width direction.

  As shown in FIG. 2, the tunnel opening 41 formed under the floor of the vehicle body by the protrusion of the floor panel 20 (floor panel main body portion 21) to the upper side of the vehicle body normally has an opening width toward the lower side of the vehicle body. The protruding portion 21a of the floor panel main body portion 21 comprising a pair of left and right inclined side wall portions facing each other and a substantially horizontal upper wall portion connecting the upper end portions of the side wall portions has a tunnel shape. Forming.

  A cylindrical exhaust pipe 30 is disposed in the tunnel opening 41 opened to the lower side of the vehicle body by the tunnel-like floor panel main body 21 in this manner so as to be separated from the inner wall surface of the tunnel. Usually, the exhaust pipe 30 is accommodated in the center of the tunnel opening 41 in the width direction. The exhaust pipe 30 is connected to the engine at the base end side in the longitudinal direction and extends from the engine, and the distal end side on the opposite side is connected to the muffler at the vehicle body rear side. That is, the exhaust pipe 30 is a flow path through which high-temperature exhaust gas from the engine passes from the base end side (front side) toward the front end side (rear side). For this reason, when the engine is driven, high-temperature exhaust gas flows from the base end (front end) side to the front end (rear end) side of the exhaust pipe 30 so that the exhaust pipe 30 is, for example, 300 ° C. or higher. Can also be heated. In particular, since the periphery of the exhaust pipe 30 is surrounded by the protruding portion 21a of the tunnel-like floor panel main body 21, the atmosphere in the tunnel opening 41 is an atmosphere that is extremely likely to rise in temperature.

  Therefore, in the floor tunnel 40 that tends to be in a high temperature state because the exhaust pipe 30 is housed in this way, in the present embodiment, as shown in FIG. 2, the floor panel main body 21 that forms the floor tunnel 40. A heat insulating coating composition as a heat insulating layer 10 is formed by applying and curing a heat insulating coating composition containing a silicone resin and hollow particles on the inner wall surface side of the tunnel around the exhaust pipe 30 with respect to the protruding portion 21a. In particular, the heat insulating paint composition of the present embodiment has good adhesion to the surface of the floor panel body 21 made of a steel plate or the like with a silicone resin, and more preferably 80% or more in terms of the adhesion rate when applied to the painted surface. 90% or more can be secured, and adhesion and adhesion to the floor panel main body 21 can be secured even after curing by simply applying to a predetermined coating site, and the formation of the heat insulating layer 10 is easy.

  And according to the heat insulation coating as the heat insulation layer 10 formed on the inner wall surface of the tunnel with respect to the floor panel main body 21 in this way, as described above, since the base material is the silicone resin 11, the exhaust pipe The exhaust pipe 30 has high heat resistance that can withstand high heat from the exhaust pipe 30 without being melted or thermally deteriorated by the high heat from 30, and the low heat conductivity of the silicone resin 11 and the heat insulating effect of the hollow particles 12. Demonstrates high heat insulation effect to insulate heat from By the predetermined | prescribed mixing | blending of the silicone resin 11 and the hollow particle 12, a heat insulation coating film has the high heat insulation whose heat conductivity is 0.08 W / (m * k) or less, for example. In such a heat insulating coating film having a low thermal conductivity, the temperature of the heat insulating coating film itself is difficult to increase, so that the paint composition is directly applied to the surface of the floor panel main body portion 21 that protects from the high heat of the exhaust pipe 30. Even if an object is applied to form a heat insulating coating as the heat insulating layer 10, the heat load on the floor panel main body 21 is small and the floor panel main body 21 is not thermally deteriorated, and heat from the exhaust pipe 30 is insulated. And the temperature rise of the floor panel main-body part 21 can be suppressed.

  Furthermore, since the base material of the heat insulating coating is a silicone resin, as described above, the adhesiveness and adhesion to the floor panel main body 21 are also high. In particular, in the case of an addition type silicone resin, the floor panel main body 21 is expanded by heat. It is possible to secure elasticity and flexibility that can follow the shrinkage and to obtain excellent adhesion and adhesion. In addition, a heat insulation coating film is formed on the surface of the floor panel main body portion 21 to be protected from high heat, and the heat insulation coating film as the heat insulation layer 10 is affected by heat from the floor panel main body portion 21 side to cause thermal deterioration or coating film. No peeling or the like occurs.

  Here, in the heat insulation structure using the conventional insulator shown in FIG. 6, since the insulator needs to be arranged at a predetermined interval with respect to the floor panel, a layer (space) between the floor panel and the insulator is required. ) Convection heat transfer occurs, and hot air from the engine may pass through the layer (space) between the floor panel and the insulator. Depending on the driving and stopping conditions of the automobile 1, the temperature of the floor panel may increase. In some cases, the temperature rises and the temperature of the upper passenger compartment space increases.

  On the other hand, the heat from the exhaust pipe 30 is formed by applying a predetermined heat insulating paint composition to the surface of the floor panel main body 21 to form a heat insulating coating as the heat insulating layer 10 as in the present embodiment. In the heat insulating structure that cuts off the heat, the adhesiveness and adhesion of the heat insulating coating as the heat insulating layer 10 with respect to the floor panel main body 21 are good, and unlike the heat insulating structure using the conventional insulator, Heat transfer due to convection does not occur between the heat insulating layer 10 and a gap through which hot air from the engine passes does not occur, so that an increase in temperature of the floor panel body 21 can be effectively suppressed. Become. That is, the heat damage of the floor panel body 21 can be suppressed, and the temperature rise in the upper vehicle interior space can be suppressed.

In addition, in the heat insulation structure using the conventional insulator, a part that causes an increase in weight is required for attaching the insulator. However, as in the present embodiment, a predetermined heat insulating paint composition is applied to the surface of the floor panel body 21. In a heat insulating structure in which an object is applied to form a heat insulating coating film as the heat insulating layer 10, the number of parts can be minimized, and the vehicle structure is not complicated, so that the weight can be reduced.
And unlike the heat insulation structure using the conventional insulator, since it is not necessary to fix to the floor panel main body 21 with an attachment member such as a bolt, no sound is generated due to vibration of the insulator or the attachment member to which the insulator is attached. . In particular, the heat-insulating coating film composed of the silicone resin 11 and the hollow particles 12 has high sound and vibration absorbability, and also has a damping effect and a soundproofing effect.

  Furthermore, according to the heat insulating coating composition containing the silicone resin and the hollow particles as described above, the heat insulating layer 10 having high heat insulating properties and high heat resistance can be obtained by applying only one liquid (one layer) to the surface of the floor panel main body 21. The heat insulation film of the floor tunnel 40 can be formed with good productivity by ensuring a heat insulation property equal to or better than that of a conventional heat insulation structure using an insulator. That is, in order to ensure the desired heat insulation properties, it is not necessary to make a composite layer that requires labor and time for the preparation and construction of the coating solution, and as a heat insulating coating 10 containing a silicone resin and hollow particles. Since it is possible to ensure heat insulation equivalent to or better than that of a conventional heat insulating structure using only a single layer, construction on the floor tunnel 40 is easy and productivity is high. That is, the preparation of the coating agent can be completed with only one liquid, and the time and labor required for the preparation of the coating agent can be reduced, and handling is easy. Further, since only one liquid needs to be applied, the time and labor required for the application work can be reduced, automatic painting by a painting robot or the like is easy, and construction on the floor tunnel 40 requires a lot of time and complicated work. Therefore, the heat insulating structure of the floor tunnel 40 can be formed with high productivity.

  Thus, in the present embodiment, the protruding portion of the floor panel main body portion 21 that forms the floor tunnel 40 in which the exhaust pipe 30 is accommodated under the floor of the vehicle such as the automobile 1 by using the heat insulating coating composition containing the silicone resin and the hollow particles. By applying to the inner wall surface of the tunnel of 21a, a heat insulating coating film that becomes the heat insulating layer 10 is formed on the surface of the floor panel body 21, and the heat from the exhaust pipe 30 is insulated by the heat insulating coating film as the heat insulating layer 10. The heat insulation structure of the floor tunnel 40 which suppresses the temperature rise of the panel main-body part 21 is comprised.

  Such a structure of the floor tunnel 40 according to the present embodiment is obtained by applying a heat insulating coating composition containing a silicone resin and hollow particles to the inner wall surface of the tunnel of the floor panel main body 21 and curing it, so that the silicone resin 11 is hollow. A heat insulating layer 10 made of a heat insulating coating film containing particles 12 is formed, and the floor panel main body 21 is formed in a tunnel shape by projecting toward the passenger compartment side above the vehicle body along the longitudinal direction of the vehicle body of the automobile 1. An exhaust pipe 30 that extends from the engine and is accommodated in a tunnel opening 41 that is formed on the lower side of the vehicle body of the floor panel main body 21, and the interior of the tunnel of the floor panel main body 21 around the exhaust pipe 30. A silicone resin 11 formed by applying a heat insulating coating composition containing a silicone resin and hollow particles on the wall surface and containing hollow particles 12. And it has a heat-insulating layer 10 made of a coating film. And the floor panel 20 which comprises the floor tunnel 40 structure of such this Embodiment apply | coats the heat insulation coating composition containing a silicone resin and a hollow particle with respect to the surface of the floor panel main-body part 21, and silicone. A heat insulating layer 10 made of a heat insulating coating film containing hollow particles 12 in the resin 11 is formed.

  Thus, in the heat insulating structure of the floor tunnel 40 in which the heat insulating coating composition containing the silicone resin and the hollow particles is applied to the inner wall surface of the tunnel of the floor panel main body 21 to form the heat insulating layer 10 made of the heat insulating coating, Is formed on the surface of the floor panel main body 21 with high adhesiveness and adhesion to the surface of the floor panel main body 21, and the heat insulating layer 10 made of a heat insulating coating film has high heat resistance due to the silicone resin 11. Due to the low thermal conductivity of the silicone resin 11 and the thermal insulation by the hollow particles 12, the thermal conductivity is low and the thermal conductivity is 0.08 W / (m · k) or less, for example. Demonstrate the effect. Further, since the heat insulating layer 10 made of a heat insulating coating is formed in close contact with the surface of the floor panel main body 21, there is no heat transfer by convection between the floor panel main body 21 and the heat insulating layer 10, and from the engine Does not create a gap through which hot air passes. Therefore, even if the heat insulation coating film formed on the surface of the floor panel main body 21 is, for example, a thin dry film thickness of 30 mm or less, the temperature rise of the floor panel main body 21 is suppressed to be equal to or higher than that of a conventional heat insulation structure using an insulator. Heat insulation effect can be obtained. In addition, the heat insulating layer 10 made of a heat insulating coating is formed in close contact with the surface of the floor panel main body 21 as described above, and no gap is generated between the floor panel main body 21 and the heat insulating layer 10 made of the heat insulating coating. Due to the heat insulating structure, it is possible to improve the aerodynamic performance of the vehicle that affects fuel consumption.

Furthermore, since it is a heat insulation structure which forms the heat insulation layer 10 which consists of a heat insulation coating film on the surface of the floor panel main-body part 21, adjustment of the mixing | blending composition of a composition, for example, the compounding quantity of a hollow particle 12, particle diameter, particle size distribution, etc. The desired heat insulation performance can be easily controlled by adjusting the thickness and the thickness of the coating film.
And in the heat insulation structure of the floor tunnel 40 formed by apply | coating the heat insulation coating composition of such this Embodiment to the surface of the floor panel main-body part 21, and forming the heat insulation layer 10 which consists of a heat insulation coating film, FIG. Unlike the heat insulation structure using the conventional insulator shown, there is no restriction of providing a distance in consideration of the interference sound with the exhaust pipe 30 or arranging a space with the floor panel main body 21. In addition, it is possible to save the space of the heat insulating structure, and to increase the degree of freedom in designing (laying out) the floor tunnel 40. That is, there are few restrictions on the tunnel space, and the tunnel space can be widened, so that the degree of freedom in designing the vehicle can be improved. Further, the tunnel opening 41 of the floor tunnel 40 can be reduced, and the space of the indoor living section can be increased by reducing the floor tunnel 40. Furthermore, in the heat insulating structure of the floor tunnel 40 in which the heat insulating paint composition of the present embodiment is applied to the surface of the floor panel main body 21 to form the heat insulating layer 10 made of a heat insulating coating film, Omitting the insulator that partitions (blocks) the space of the tunnel opening 41 is advantageous in improving the aerodynamic performance of the vehicle. In addition, vibration of the insulator and the mounting member for mounting the insulator on the floor panel and sound generation due to the vibration are eliminated, and the heat insulating coating film containing the hollow particles 12 in the silicone resin 11 has vibration damping properties and soundproofing that suppress vibration. Excellent in properties. In particular, the addition-type silicone resin 11 has a predetermined viscosity characteristic, has high followability to the floor panel main body 21 and high adhesion, and provides high vibration damping properties. The heat insulating layer 10 made of a heat insulating coating film containing hollow particles 12 in the resin 11 is applied to a floor tunnel 40 extending along the front-rear direction of the vehicle body under the floor of the vehicle as shown in FIG. Since it is applied to a wide range of floor panels, it can effectively suppress floor vibrations and contribute to improving the quietness of the room (inside the vehicle).

  Here, according to an experimental study by the present inventor, when higher heat insulating properties are required, there is a limit to the improvement of heat insulating properties from the viewpoint of coating workability only with hollow particles. That is, as the blending amount of the hollow particles increases, the coating workability decreases due to the decrease in fluidity and viscosity of the composition, and the increase in the blending amount of the hollow particles is limited from the viewpoint of coating workability. Therefore, when the thermal conductivity of the coating is required to be higher, for example, 0.06 W / mk or less, as shown in FIG. 3, in addition to the hollow particles 12 such as a thermoplastic resin microballoon, the coating is applied. It is preferable to use a heat-expandable microcapsule 13A that is expanded by a heat treatment later, for example, a heat treatment such as baking drying for curing the resin, or a foaming agent 14A that is thermally decomposed by the heat treatment to generate gas. The combined use of the hollow particles 12 such as thermoplastic resin microballoons and the thermally expandable microcapsules 13A and / or the foaming agent 14A can improve the heat insulation without reducing the coating workability.

  The thermally expandable microcapsule 13A has, for example, a boiling point not higher than the softening temperature of the thermoplastic resin constituting the shell in the inside (core) of the shell (shell wall, outer shell) made of a thermoplastic resin such as acrylonitrile. A thermoplastic resin microcapsule having a structure in which a vaporized substance (for example, a low-boiling hydrocarbon or the like) is enclosed is used. That is, this thermally expandable thermoplastic resin microcapsule is a capsule having a shell structure made of a thermoplastic resin including a vaporized substance in the core, and after application to the painted surface, the temperature exceeds the softening temperature of the shell. When the temperature reaches a predetermined temperature range by heating, the shell softens, the vaporized substance contained in the shell changes to gas, and the shell increases due to the increase in gas pressure (expansion force / vapor pressure) in the shell. It expands to increase the volume, and becomes a hollow thermoplastic microballoon (hollow particle). For example, when the particle diameter (median diameter) is 5 to 50 μm, the volume change is about 50 to 100 times.

  As the thermoplastic resin constituting the shell of this thermoplastic resin microcapsule, for example, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylonitrile vinylidene chloride copolymer, acrylonitrile methyl methacrylate copolymer, acrylamide, Examples thereof include acrylic acid, acrylic acid ester, methacrylamide, methacrylic acid, methacrylic acid ester, vinyl acetate, vinylidene chloride-acrylonitrile copolymer, acrylonitrile methacrylic acid, and methyl copolymer.

  The shell of the heat-expandable thermoplastic resin microcapsule is also mainly composed of the above-mentioned thermoplastic resin, but may contain other components, and the manufacturing method of the heat-expandable microcapsule 13A is particularly questioned. Absent. Commercially available (for example, Matsumoto Microsphere (registered trademark) F, FN series manufactured by Matsumoto Yushi Seiyaku Co., Ltd.), Expandel (registered trademark) manufactured by Nippon Ferrite Co., Ltd., and Fine manufactured by Dainichi Seika Kogyo Co., Ltd. It is also possible to obtain and use unexpanded thermally expandable microcapsules of Cellmaster, Kureha Microsphere manufactured by Kureha Co., Ltd., or to manufacture and use them by a conventionally known method. Is possible. For example, radically polymerizable monomers such as acrylonitrile and vinyl chloride, and any crosslinking agent (eg, divinylbenzene, (poly) ethylene glycol (di) methacrylate, triallyl isocyanurate (TAIC), trimethylolpropane trimethacrylate) (TMP, triacryl formal (TAF), etc.) and a mixture obtained by mixing a monomer mixture containing a polymerization initiator and a foaming agent (organic solvent), an aqueous system containing an appropriate dispersion stabilizer, etc. Thermally expandable microcapsules can be produced by suspension polymerization in suspension and used.

Such heat-expandable microcapsules (non-expanded microcapsules) 13A preferably have an average particle diameter (median diameter) of 5 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less. If it is such a size, it has the pressure resistance and mechanical strength which are hard to be destroyed at the time of application, and can secure uniform dispersibility, application workability, and application nature.
In particular, since the thermoplastic resin microballoon obtained by expanding the thermoplastic resin microcapsules has a small true specific gravity as described above, the coating film can be reduced in weight (lower specific gravity). Furthermore, as described above, from the thickness of the outer shell and the characteristics of the heat-plastic plastic resin, it is difficult to break due to its high elasticity, and it is easy to control the predetermined porosity for exhibiting a high heat insulating effect. In addition, the strength and flexibility of the coating film against pulling and bending can be enhanced.

  In the heat insulating coating composition of the present embodiment, when such a heat-expandable microcapsule 13A is contained, the heat insulating coating composition is applied to a predetermined portion and then heated at a predetermined temperature by a predetermined heat treatment. Resin microballoons in which the microcapsules are expanded (previously expanded microcapsules) are obtained by softening the thermoplastic resin constituting the shell of the expandable microcapsule 13A and gasifying the vaporized substance such as low-boiling hydrocarbons contained in the shell. Capsule) 13B. In particular, when the coating film of the heat-insulating coating composition of the present embodiment is cured by heating, the microcapsules are usually expanded at the heat treatment temperature during baking and drying for curing the coating film to form a microballoon. Microcapsules 13A are selected. For example, the thermally expandable microcapsule 13A having an expansion start temperature that is equal to or lower than the heating temperature during baking and drying is selected. The expansion start temperature means that when the thermally expandable microcapsule 13A is heated, softening of the thermoplastic resin constituting the shell starts, and at the same time, the encapsulated vaporized substance such as hydrocarbons. This is the temperature at which the internal pressure increases by starting gasification and the microcapsules start to expand. For example, microcapsules having an expansion start temperature of 60 ° C. to 130 ° C., preferably 70 ° C. to 110 ° C. can be used. If the thermal expansion microcapsule 13A has an expansion start temperature within the above temperature range, the heating temperature (usually 120 ° C. to 120 ° C.) during baking and drying of the intermediate coating or outer coating used in the current automobile coating line. At 160 ° C., the shell does not rupture, and a hollow resin microballoon 13B having a high expansion rate is obtained. Thus, in the heat insulating coating composition containing the thermally expandable microcapsule 13A, the inclusion of the thermally expandable microcapsule 13A undergoes volume expansion when heated at a temperature equal to or higher than the expansion start temperature of the thermally expandable microcapsule 13A. Capsules in which the shell is softened and expanded, that is, hollow particles 13B made of resin microballoons, are dispersed and contained in the silicone resin 11 which is the base material of the coating film.

  And in the heat insulation coating composition of this Embodiment, as shown to Fig.3 (a), in addition to the hollow particle 12, when it contains such a thermally expansible microcapsule 13A, a painted surface, for example, floor Thermal insulation as the heat insulation layer 10 formed on the surface of the floor panel body 21 by forming the resin microballoon 13B by thermally expanding the thermally expandable microcapsules 13A by heat treatment after application to the surface of the panel body 21. In the coating film, in addition to the hollow particles 12 such as the original thermoplastic resin microballoon blended in the composition, the thermally expandable microcapsule 13A has a resin microballoon (hollow particle) 13B formed by thermal expansion, A high heat insulating effect is exhibited by the hollow particles 12 and the resin microballoon (hollow particles) 13B. In particular, by using such thermally expandable microcapsules 13A in combination with hollow particles 12 such as thermoplastic resin microballoons, it is possible to improve the heat insulation without reducing the coating workability.

  Moreover, as foaming agent 14A mix | blended with a heat insulating coating composition, ADCA (azodicarbonamide), azobisisobutyronitrile (AIBN), dinitrosopentamethylenetetramine (DPT), p-toluenesulfonyl hydrazide (TSH), Organic blowing agents such as p-toluenesulfonyl azide, p-methylurethanebenzenesulfonyl hydrazide, benzenesulfonyl hydrazide (BSH), and oxybenzenesulfonyl hydrazide (OBSH), and inorganic blowing agents such as sodium hydrogen carbonate (bicarbonate) can be used. When the coating film of the heat insulating coating composition of the present embodiment is cured by heating, a heating type foaming agent is preferably used. The heating-type foaming agent is a foaming agent that decomposes by heating to generate gas and foam. When such a heating type foaming agent is contained, it is desirable that the foaming agent 14A decomposes and foams depending on the heat treatment temperature when the coating film is cured after the heat insulating coating composition is applied to a predetermined site. . If necessary, it is possible to use a foaming aid that assists the foaming action of the foaming agent 14A, and the foaming aid is blended so as to foam in accordance with the heating conditions during baking and drying to cure the coating film. However, the foaming aid is not necessarily required depending on the heating conditions and the like.

  And in the heat insulation coating composition of this Embodiment, as shown in FIG.3 (b), when it contains such a foaming agent 14A in addition to the hollow particle 12, it is a coating surface, for example, a floor panel main-body part. When the foaming agent 14A is foamed by the heat treatment after the application to the surface 21, the heat insulating coating as the heat insulating layer 10 formed on the surface of the floor panel main body 21 has the hollow particles 12 and the bubbles 14B. A high heat insulating effect is exhibited by the hollow particles 12 and the bubbles 14B. In particular, by using the foaming agent 14A in combination with the hollow particles 12 such as thermoplastic resin microballoons, the heat insulation can be improved without deteriorating the coating workability. Moreover, the lightweight effect of a coating film also becomes a high thing by containing the bubble 14.

  As described above, in addition to the hollow particles 12, the thermal expansion microcapsules 13A or the foaming agent 14A can be used together to improve the heat insulation without reducing the coating workability. These heat-expandable microcapsules 13A and foaming agent 14A can be used in combination. That is, the hollow particles 12, the thermally expandable microcapsules 13A, and the foaming agent 14A can be used in combination. In particular, when the thermally expandable microcapsule 13A and the foaming agent 14A are used in combination and the coating film is cured by heating such as baking and drying, heating type foaming that starts foaming at a temperature higher than the temperature at which the microcapsule starts to expand. It is desirable to use an agent so that the heating type foaming agent decomposes and foams at a temperature higher than the expansion start temperature of the microcapsules. That is, the relationship between the microcapsule expansion start temperature and the foaming start temperature is such that the microcapsule starts to expand first and then the decomposition of the foaming agent starts. As a result, the coating film is cured at a heating temperature (usually 120 ° C. to 160 ° C.) during baking and drying of the intermediate coating or outer coating used in the current automobile coating line, and within a predetermined temperature range. The expansion of the microcapsule starts, and then the foaming agent foams at a temperature higher than the expansion start temperature of the microcapsule, so that the foaming agent foams in a state where the coating layer becomes thick due to the expansion of the microcapsule. The retention of the foaming gas by the agent is enhanced, and the foaming efficiency, the porosity, and the desired thickness can be easily controlled. Therefore, setting of desired heat insulation becomes easy. Moreover, depending on the temperature at the time of baking and drying, even if the microcapsule expands as the temperature rises and then starts to shrink, a desired thickness and voids can be secured by foaming with a foaming agent, and high heat insulation can be secured.

Next, examples of the heat insulating paint composition according to the embodiment of the present invention will be specifically described.
In the present embodiment, as shown in FIGS. 1 and 2, the surface of the floor panel body 21 that forms the floor tunnel 40 in which the exhaust pipe 30 is accommodated under the floor of the body of the automobile 1, more specifically, the floor panel body As the blending composition of the heat insulating paint composition applied to the inner wall surface on the tunnel opening 41 side in the protruding part 21a of the part 21, the heat insulating paint compositions according to Examples 1 to 3 were produced with the contents shown in Table 1. . Moreover, the coating composition which concerns on the comparative example 1 was also produced for the comparison. The composition of each example and comparative example is shown in the upper part of Table 1.

  The heat-insulating coating composition according to Example 1 includes 100 parts by weight of an addition-type silicone resin (“KE-109E-A / B” manufactured by Shin-Etsu Chemical Co., Ltd.) and thermoplastic resin microballoons (existing). Expanded microcapsules) (Matsumoto Yushi Seiyaku Co., Ltd. “Matsumoto Microsphere (registered trademark) MFL-82D, F-48D, F-78KD”); true specific gravity: 0.12 ± 0.02, average particle size (product) Display): 60 to 70 μm, 16 parts by weight of acrylonitrile-based thermoplastic polymer shell (shell) coated with calcium carbonate).

The heat-insulating coating composition according to Example 2 includes 100 parts by weight of an addition-type silicone resin (“KE-109E-A / B” manufactured by Shin-Etsu Chemical Co., Ltd.) and thermoplastic resin microballoons (existing). Expanded microcapsules) (Matsumoto Yushi Seiyaku Co., Ltd. “Matsumoto Microsphere (registered trademark) MFL-82D, F-48D, F-78KD”); true specific gravity: 0.12 ± 0.02, average particle size (product) Indication): 60 to 70 μm, 16 parts by weight of acrylonitrile-based thermoplastic polymer shell (shell coated with calcium carbonate), and thermoplastic resin microcapsule (not yet expandable) Expansion microcapsule) (Nippon Philite Co., Ltd .; “Expancel (registered trademark) 031-40DU”, expansion start temperature: 80-95 ° C. , Maximum expansion temperature: 120 to 135 ° C., average particle diameter (product display): 10 to 16 μm, true density: 1.2 g / cm ³ or less) is blended in an amount of 3 parts by weight.

  The heat-insulating coating composition according to Example 3 includes 100 parts by weight of an addition-type silicone resin (“KE-109E-A / B” manufactured by Shin-Etsu Chemical Co., Ltd.) and thermoplastic resin microballoons (existing). Expanded microcapsules) (Matsumoto Yushi Seiyaku Co., Ltd. “Matsumoto Microsphere (registered trademark) MFL-82D, F-48D, F-78KD”); true specific gravity: 0.12 ± 0.02, average particle size (product) Indication): 60 to 70 μm, 16 parts by weight of an acrylonitrile-based thermoplastic polymer shell (shell coated with calcium carbonate) and an asodicarbonamide (ADCA) -based foaming agent (Yewa Kasei Kogyo ( 3 parts by weight of “FE-788” manufactured by the same company).

  On the other hand, the heat-insulating coating composition according to Comparative Example 1 is composed of only 100 parts by weight of an addition-type silicone resin (“KE-109E-A / B” manufactured by Shin-Etsu Chemical Co., Ltd.).

Next, the heat insulation evaluation test was done about each coating composition of the Example of such a compounding composition, and a comparative example.
In the heat insulation evaluation test, each coating composition was applied to a predetermined application object and cured by heating to obtain a heat insulating coating, and the thermal conductivity of the heat insulating coating was examined. In addition, the structure of the floor tunnel 40 in which the exhaust pipe 30 is accommodated under the floor of the automobile 1 is schematically reproduced. That is, as shown in FIG. 4, a tunnel-shaped steel plate S is arranged around the heater H as a heat source. Then, each of the coating compositions of Examples and Comparative Examples was applied to the surface of the steel sheet S around the heater H, and cured by heating to form a heat insulating coating film, and the heater H was heated. The temperature rise of S was investigated and the temperature rise suppression effect of the steel sheet S by the heat insulation coating film formed from each coating composition was evaluated.

  In addition, preparation of each coating composition of the Example and Comparative Example which consist of these compounding compositions was performed by, for example, carrying out vacuum defoaming stirring for 15 minutes, after mixing materials uniformly using a planetary mixer.

  Here, with respect to the thermal conductivity [W / (m · K)], HC-074 of Eihiro Seiki Co., Ltd. is used as a thermal conductivity measuring device, and based on the heat flow meter method (based on JIS A1412-2). The heat flow rate was measured, and the thermal conductivity [W / (m · K)] of the heat insulating coating was calculated.

  Further, as shown in FIG. 4, the structure of a floor tunnel 40 in which the exhaust pipe 30 is accommodated under the floor of the vehicle body, a heater H (Φ50 mm) of the heat source is formed on the lower opening side of the tunnel-shaped steel plate S (length: 300 mm). × 300 mm) is placed, and the coating compositions of the examples and comparative examples are applied to the surface of the steel sheet S above the heater H, and then baked and dried under heating conditions of 140 ° C. × 30 minutes. Heat-curing was performed and the heat insulation coating film as the heat insulation layer 10 was obtained. This heat treatment condition is the same as the heating condition at the time of baking and drying of the intermediate coating or the outer coating applied in the current automobile coating line. Thus, a hardened coating film having a dry film thickness t of 5 mm on the surface of the steel sheet S on the inner wall surface (upper surface side) of the steel sheet S in which the heater H is accommodated, that is, a heat insulating coating made of each coating composition of the examples and comparative examples. A film (heat insulating layer 10) was formed. At this time, the distance d between the heat insulating coating (heat insulating layer 10) formed on the surface on the inner wall surface side of the tunnel of the steel plate S and the heater H of the heat source was 30 mm.

  In this way, the heater H as a heat source is arranged in the tunnel of the steel plate S having a tunnel shape shown in FIG. In the structure in which the heat insulating layer 10 made of a heat insulating coating is formed on the surface of the inner wall surface side (upper wall surface) of the steel plate S on the upper side, the heat insulating layer 10 side when the temperature of the heater H is 300 ° C. By measuring the surface temperature of the steel plate S on the opposite side with the thermocouple T, the heat insulating effect by the heat insulating coating film (heat insulating layer 10) formed from each coating composition of the examples and comparative examples, that is, the temperature of the steel plate S The rise inhibitory effect was evaluated.

The evaluation results of the heat insulating properties of the heat insulating coatings formed from the coating compositions of Examples and Comparative Examples are shown in Table 1 together with the measurement results of the thermal conductivity and the measurement results of the temperature rise of the steel sheet S (maximum temperature reached). As shown in the bottom row.
Here, the heat insulation was evaluated in three stages: ◎, ○, ×. That is, if the thermal conductivity of the heat insulating coating is 0.08 [W / (m · K)] or less, the heat insulation sufficient to ensure the heat insulation equivalent to or better than the heat insulation structure using the conventional insulator. It judged as having (circle) (pass), and the thermal conductivity of the heat insulation coating film exceeded 0.08 [W / (m * K)], and evaluated as x (failure). Moreover, in the heat insulation measurement test using the heater H as shown in FIG. 4, the surface temperature of the steel sheet S on the side opposite to the heat insulating layer 10 side is 80 ° C. due to the formation of the heat insulating coating (heat insulating layer 10). When exceeding, it is evaluated as x (failed), and the case where the surface temperature of the steel sheet S on the side opposite to the heat insulating layer 10 side is suppressed to 80 ° C. or less by the formation of the heat insulating coating film (heat insulating layer 10). (Passed). Furthermore, the thermal conductivity of the heat insulating coating is 0.05 [W / (m · K)] or less, and the surface temperature of the steel sheet S on the side opposite to the heat insulating layer 10 side due to the formation of the heat insulating coating (heat insulating layer 10). When the temperature was suppressed to 78 ° C. or less, the heat insulation effect was differentiated with ◎.

As shown in the lower part of Table 1, according to the heat insulating paint compositions of Examples 1 to 3 containing a silicone resin and hollow particles, compared with the heat insulating paint composition of Comparative Example 1 consisting of only a silicone resin. In either case, the thermal conductivity of the heat-insulating coating film was 0.055 [W / (m · K)] or less, and a heat-insulating coating film with low thermal conductivity was obtained.
In particular, in Example 2 and Example 3, a heat insulating coating film having an extremely low thermal conductivity of 0.05 [W / (m · K)] or less can be obtained without reducing the coating workability. It was.

Further, the heat insulating coating film made of each of the heat insulating coating compositions of Examples 1 to 3 and Comparative Example 1 is dried on the surface of the tunnel-shaped steel sheet S above the heater H as a heat source, and the dry film thickness (t) is 5 mm. When the heater H was heated to 300 ° C., the temperature increase of the steel sheet S when the heater H was heated was measured and the heat insulating effect by the heat insulating coating (heat insulating layer 10) was evaluated. In the heat-insulating coating film (heat-insulating layer 10) according to Comparative Example 1 consisting only of the silicone resin 11, the surface temperature of the steel sheet S on the side opposite to the heat-insulating layer 10 side reached 82.7 ° C. In the heat insulation coating film (heat insulation layer 10) which concerns on 1 thru | or Example 3, the surface temperature of the steel plate S on the opposite side to the heat insulation layer 10 side was suppressed to 79 degrees C or less.
In addition, as for the heat insulation coating film (heat insulation layer 10) which consists of each heat insulation coating material composition of these Examples 1 thru | or Example 3 and the comparative example 1, all have favorable adhesiveness (when apply | coated to the coating surface). The adhesion rate was 90% or more).

In particular, in Example 2 in which a thermally expandable thermoplastic resin microcapsule was blended in addition to the addition-type silicone resin and the thermoplastic resin microballoon, the thermal conductivity was as extremely high as 0.047 [W / (m · K)]. A heat insulating coating film having a low thermal conductivity is obtained, and according to the heat insulating coating film according to Example 2, the temperature rise of the surface of the steel sheet S on the side opposite to the heat insulating layer 10 side is 77.9 ° C. or less. It was suppressed to.
As shown in FIG. 3A, the addition type silicone resin as the silicone resin 11, the thermoplastic resin microballoon as the hollow particle 12, and the thermoplastic resin microcapsule as the thermally expandable microcapsule 13A are blended. The heat insulating coating film (heat insulating layer 10) formed by applying the heat insulating coating composition to a predetermined application site and curing by heating is the thermoplastic resin microballoon 12 (hollow particles) originally blended with the composition. A thermoplastic resin microballoon 13B (hollow particles) formed by expanding the thermoplastic resin microcapsules 13A blended in the composition is contained in the addition-type silicone resin 11, and is originally blended in the composition. The thermoplastic resin microphone blended in the composition with the hollow particles derived from the thermoplastic resin microballoon 12 It contains the hollow particles from the capsule 13A.

Further, in Example 3 in which a chemical foaming agent was blended in addition to the addition type silicone resin and the thermoplastic resin microballoon, the thermal conductivity was as extremely low as 0.043 [W / (m · K)]. A heat insulating coating film was obtained, and according to the heat insulating coating film according to Example 3, the temperature increase of the surface of the steel sheet S on the side opposite to the heat insulating layer 10 side could be suppressed to 77.4 ° C. or lower.
As shown in FIG. 3B, a heat insulating paint comprising the addition type silicone resin as the silicone resin 11, the thermoplastic microballoon as the hollow particles 12, and the ADCA foaming agent as the foaming agent 14A. A heat insulating coating (heat insulating layer 10) obtained by applying the composition to a predetermined application site and curing by heating is added to the thermoplastic resin microballoon 12 (hollow particles) originally included in the composition and the composition. The addition-type silicone resin 11 contains the bubbles 14B formed by foaming of the ADCA-based foaming agent 14A.

Here, further about the heat insulation performance of the heat insulating structure of the floor tunnel 40 formed using the heat insulating coating composition according to Example 1 made of silicone resin and hollow particles, the heat insulating structure in the floor tunnel 40 using a conventional insulator and A comparison was made.

  That is, as shown in FIG. 5, the structure of the floor tunnel 40 in which the exhaust pipe 30 is housed under the floor of the vehicle is schematically reproduced, and a tunnel-shaped steel plate S is disposed around the heater H as a heat source. The coating composition of Example 1 was applied to the surface on the inner wall surface side of the tunnel of the steel plate S around H to form a heat insulating coating (heat insulating layer 10), and the heater H was heated to 270 ° C. The temperature was measured and compared with the temperature rise of the steel sheet S in the heat insulating structure in which the insulator was arranged.

  Specifically, as shown in FIG. 5, a heater H (Φ50 cm × 300 mm) as a heat source is arranged on the lower opening side of the tunnel-shaped steel plate S (length: 300 mm), and in FIG. A coating composition comprising the silicone resin and hollow particles of the above Example 1 is applied to the inner wall surface (upper wall surface and left and right sidewall surfaces) of the steel sheet S, and then baked and dried under heating conditions of 140 ° C. × 30 minutes. The coating film was heat-cured. Thus, a cured coating film, that is, a heat insulating coating film made of the coating composition of Example 1, was formed on the inner wall surface of the tunnel of the steel sheet S around the heater H housed in the tunnel of the steel sheet S. Here, two types of thermal insulation coating films according to Example 1 were tested, those having a dry film thickness (t) of 5 mm and those having a dry film thickness (t) of 10 mm.

And, as shown in FIG. 5A, the heater H as a heat source is accommodated in the tunnel of the steel plate S as shown in FIG. Heat insulation when the temperature of the heater H is 270 ° C. and the wind speed is 0.8 m / S in a structure in which a heat insulating layer 10 made of a heat insulating coating film with a predetermined film thickness is formed on the surface of the steel sheet S. The temperature rise of the surface of the steel sheet S on the side opposite to the layer 10 side was measured with a thermocouple T. The distance d ₁ between the heater H of the heat source (the side opposite to the heat-insulating layer 10 formed side) temperature measurement site of the steel sheet S surface by the thermocouple T is set to 35 mm. Further, as shown in FIG. 5A, the coating material of Example 1 is applied to the entire periphery of the inner peripheral wall surface of the tunnel, that is, the entire side wall surface side and upper wall side surface of the tunnel. The composition is applied to form a heat insulating layer 10 made of a heat insulating coating film, and the distance d ₂ between the outer wall surface of the steel sheet S opposite to the heat insulating layer 10 forming side and the heater H is set to 35 mm.

On the other hand, for comparison, as shown in FIG. 5B, the temperature of the surface of the steel sheet S when the insulator I is arranged around the heater H without forming the heat insulating layer 10 made of a heat insulating coating film. The rise was also measured. That is, as shown in FIG. 5B, the tunnel-shaped insulator I is disposed so as to surround the heater H (Φ50 cm × 300 mm) disposed on the lower opening side of the tunnel-shaped steel sheet S (length: 300 mm). The temperature rise of the surface of the steel sheet S on the side opposite to the insulator I side when the temperature of the heater H was 270 ° C. and the wind speed was 0.8 m / S was measured with a thermocouple T. Incidentally, (the insulator arranged side opposite) Temperature measurement site of the steel sheet S surface with thermocouples T distance d ₁ between the heater H of the heat source is set to 35 mm. Further, the heat insulating layer 10 formed side distance d ₂ between the outer wall and the heater H of the steel sheet S on the opposite side is 35 mm, are arranged so that the insulator I fit a distance d3 away 10mm steel plate S.

5A and 5B, the heater H is attached to the tunnel-shaped steel plate S by using a hanger rubber or the like (not shown), and FIG. ) Is also attached to the tunnel-shaped steel plate S using hanger rubber or the like (not shown).
As shown in FIGS. 5 (a) and 5 (b), a tunnel-shaped steel plate S and a heater H are disposed in a predetermined manner for the heat insulation evaluation test, the temperature of the heater H is 270 ° C., and the wind speed is 0.8 m / Table 2 shows the measurement result (maximum temperature reached) of the surface temperature of the steel sheet S under the condition of S.

  As shown in Table 2, in the heat insulating structure (FIG. 5B) in which the insulator I is arranged around the heater H in the tunnel in which the heater H is accommodated, the surface of the steel sheet S on the opposite side to the insulator I side. Was 57.2 ° C., and the coating composition of Example 1 was applied to the surface of the steel sheet S in the tunnel in which the heater H was accommodated to form the heat insulating layer 10 made of a heat insulating coating. In the heat insulation structure (FIG. 5 (a)), when the film thickness (dry film thickness) t of the heat insulation coating film was 10 mm, the maximum temperature reached on the surface of the steel sheet S could be suppressed to 54.3 ° C.

  Thus, according to the heat insulating coating composition according to Example 1 composed of the silicone resin and the hollow particles, the heat resistance is high, and the coating strength is maintained without being melted or thermally deteriorated even when arranged around a high heat source. Thus, a heat insulating coating having a low heat conductivity and a high heat insulating property is obtained by the low thermal conductivity of the silicone resin and the heat insulating effect of the hollow particles, and this heat insulating coating is formed on the surface of the steel sheet S in the tunnel in which the heater H is accommodated It was confirmed that the heat insulation structure can obtain heat insulation performance equal to or higher than that of a conventional heat insulation structure using an insulator. In particular, due to the high heat insulating property of the heat insulating layer 10 made of a heat insulating coating film, a heat insulating performance superior to a heat insulating structure using a conventional insulator was obtained if the thickness was 10 mm.

  Therefore, in the heat insulating structure in which a predetermined heat insulating coating composition is applied to the surface of the steel sheet S in the tunnel in which the heater H is accommodated to form the heat insulating layer 10 made of a heat insulating coating, the heat insulating layer 10 is in close contact with the surface of the steel sheet S. Unlike the structure using a conventional insulator, it is not necessary to provide a space between the steel sheet S and the interference sound with respect to the exhaust pipe 30. Therefore, the distance from the exhaust pipe 30 can be reduced. And by the high heat insulation effect of the heat insulation layer 10 which consists of a heat insulation coating film, even if it is thin, the heat insulation equivalent to or more than the structure using the conventional insulator is exhibited, and the temperature rise of the steel plate S can be suppressed effectively. Therefore, it is possible to save the space of the heat insulating structure and increase the degree of freedom in tunnel design (layout).

  Here, the inventor of the heat insulating coating composition applied to the surface of the floor panel main body portion 21 forming the floor tunnel 40 described above in order to obtain a heat insulating property equivalent to or higher than that of a heat insulating structure using a conventional insulator. As a result of extensive experimental research on the blending composition, the blending amount of the thermoplastic resin microballoon as the hollow particles is 8.1 parts by weight or more and 26.7 parts by weight with respect to 100 parts by weight of the addition-type silicone resin as the silicone resin. It has been found that a suitable composition is within the range of less than or equal to parts.

  That is, when the blending amount of the thermoplastic resin microballoon as the hollow particles is less than 8.1 parts by weight with respect to 100 parts by weight of the addition-type silicone resin as the silicone resin, the thermal conductivity of the heat insulating coating is 0.08 W / It is not practical because it is difficult to obtain a high heat insulating property of (m · k) or less, and it is difficult to realize a heat insulating effect equivalent to a heat insulating structure using a conventional insulator and a space saving of the heat insulating structure. On the other hand, when the blending amount of the thermoplastic resin microballoon as the hollow particles exceeds 26.7 parts by weight, viscosity and fluidity suitable for coating cannot be obtained, and coating workability cannot be ensured.

  If the compounding amount of the thermoplastic resin microballoon as the hollow particles is within the range of 8.1 parts by weight to 26.7 parts by weight with respect to 100 parts by weight of the addition type silicone resin as the silicone resin, the thermal conductivity Can obtain a heat insulating coating film having a high heat insulating property of 0.08 W / (m · k) or less, and a dry film thickness is, for example, a thin thickness within a range of 30 mm or less, and a conventional insulator is used. Ensures heat insulation equivalent to or better than the heat insulation structure, and enables space saving of the heat insulation structure.

  Further, as described above, in addition to the thermoplastic resin microballoon as the hollow particles, the use of the thermoplastic resin microcapsule as the thermally expandable microcapsule and the ADCA-based foaming agent as the foaming agent enables application workability. Although it is possible to improve the heat insulation without lowering the film thickness, film formation becomes difficult if the amount of the thermally expandable microcapsules or the foaming agent is too large, according to the experimental study by the present inventors. Therefore, the blending amount of the thermoplastic resin microcapsule as the thermally expandable microcapsule or the ADCA foaming agent as the foaming agent is preferably 20 parts by weight or less with respect to 100 parts by weight of the addition-type silicone resin as the silicone resin. More preferably, if it is 15 parts by weight or less, and more preferably 13 parts by weight or less, it is possible to achieve both high heat insulation and coating strength. When both the thermoplastic resin microcapsule as the thermally expandable microcapsule and the ADCA-based foaming agent as the foaming agent are blended, the total blending amount thereof is 100 parts by weight of the addition-type silicone resin as the silicone resin. On the other hand, it is preferably 25 parts by weight or less.

  Here, the present inventors have further conducted diligent experimental research, from the viewpoint of the coating workability to be applied to the floor panel body portion 21 made of a steel plate or the like, in this way, addition type silicone resin as a silicone resin and thermoplastic resin micro as a hollow particle. The viscosity of the heat insulating coating composition containing the balloon is preferably in the range of 1 Pa · s / 25 ° C. or higher and 1000 Pa · s / 25 ° C. or lower. As long as the viscosity of the heat insulating coating composition is in the range of 1 Pa · s / 25 ° C. or higher and 1000 Pa · s / 25 ° C. or lower, the coating productivity is good, and the viscosity characteristics suitable for the coating work are ensured. And stable coating quality can be obtained. In addition, this viscosity is based on JISK7117-1, and was measured on the temperature conditions of rotation speed 20rpm and 25 degreeC using the B-type rotational viscometer.

  More preferably, if the viscosity of the heat-insulating coating composition is 10 Pa · s / 25 ° C. or higher, and more preferably 30 Pa · s / 25 ° C. or higher, high adhesion to the painted surface is obtained and the coating film is cured. High adhesion and adhesion can be secured. Therefore, high heat insulation is exhibited stably. In particular, when high adhesion to the painted surface of the floor panel body 21 is obtained, hot air can be prevented from entering the gap between the floor panel body 21 and the temperature of the floor panel body 21 can be effectively increased. A heat insulating structure that can be blocked can be formed. Furthermore, after the coating film is cured, it becomes a heat insulating coating film having flexibility and elasticity following the floor panel main body 21, and is not easily peeled off or cracked, and can exhibit stable coating film performance.

  Further, according to the experimental study of the present inventor, it is preferable to apply the heat insulating coating composition to the inner wall surface of the tunnel of the floor panel body 21 so that the dry film thickness is in the range of 0.1 mm to 30 mm. . If the film thickness is too small, it will not be possible to ensure the same or better heat insulation than the conventional insulation structure using an insulator. On the other hand, if the film thickness is too thick, the weight will be heavy, and space for the heat insulation structure will be taken up. Furthermore, unevenness is likely to occur and the paintability and paint efficiency are also reduced. Therefore, the heat-insulating coating composition is prepared so that the dry film thickness of the heat-insulating coating film is within a range of 0.1 mm to 30 mm, and more preferably within a range of 5 mm to 15 mm from the viewpoint of stably ensuring high heat insulating properties. By applying, the desired heat insulation effect is obtained, the restriction of the tunnel space is reduced, and the applicability is good and the light weight is excellent. In particular, according to the heat insulating paint composition comprising hollow particles in a silicone resin, even with such a thin film, it is possible to secure a heat insulating property equal to or better than that of a conventional heat insulating structure using an insulator and to save space in the heat insulating structure. And

  Furthermore, as described above, according to the present inventors' experimental research, in order to obtain a heat insulating property equivalent to or better than that of a conventional heat insulating structure, a heat insulating coating composition containing a silicone resin and hollow particles is obtained. The heat insulating film to be formed preferably has a thermal conductivity (based on JIS A 1412-2 (heat flow meter method)) of 0.08 W / (m · k) or less. More preferably, the thermal conductivity is 0.06 W / mk or less, and still more preferably, the thermal conductivity is 0.05 W / (m · k) or less. If it is a heat insulating coating with a thermal conductivity of 0.08 W / (m · k) or less, it has high heat insulating properties, and the conventional insulator is used even when the dry film thickness is, for example, a thin thickness within a range of 30 mm or less. Ensures heat insulation equivalent to or better than the heat insulation structure used, enabling space saving of the heat insulation structure. In particular, if the thermal conductivity is 0.06 W / (m · k) or less, the dry film thickness is, for example, as high as or better than that of a conventional heat insulating structure even with a thin film thickness of 20 mm or less. This makes it possible to save space in the heat insulating structure.

In addition, in order to specify the properties of the heat insulating coating film containing the silicone resin and the hollow particles, the present inventor paid attention to the coating film density and voids. Thermal conductivity is 7 g / cm ³ or less, more preferably 0.6 g / cm ³ or less, and the porosity calculated from the coating film density is 38% or more, more preferably 40% or more. It was confirmed that a heat insulating coating film having a thickness of 0.08 W / (m · k) or less was obtained. In addition, this coating-film density measures the whole weight about the heat insulation coating apply | coated to arbitrary base materials, the dimension of a heat insulation coating, and considers the weight of a base material, thickness, etc., and a coating-film density (g / Cm ³ ). Moreover, the heat insulating property by hollow particles or bubbles was captured by a void portion containing air, and the void ratio was specified. That is, the coating film density D (g / cm ³ ) is the air density (0.01293 g / cm ³ ) of D1, and the resin density (for example, the addition type silicone resin used in Examples 1 to 3 above). When the resin density is 0.965 g / cm ³ ) and D2 and the porosity is x, it can be expressed as D = D1 (1-x) + D2 · x, and these coating film density D and air density D1 The porosity x was calculated from the resin density D2. From the viewpoint of coating film strength, the coating film density is preferably 0.1 g / cm ³ or more, and the porosity is preferably 90% or less.

That is, when the coating film density is low and the porosity is high, the coating film strength is reduced and cracks, cracks, etc. are likely to occur, the adhesion to the floor panel body 21 is lacking, and the surface of the floor panel There is a risk that hot air from the engine may enter the gap with the coating film, and stable heat insulation performance cannot be obtained. On the other hand, in the case where the coating film density is high and the porosity is low, it is possible to ensure the heat insulation property equivalent to or better than the heat insulation structure using the conventional insulator with the thickness of the coating film that enables space saving of the heat insulation structure. Can not.
Coating density is in the range of ^{0.1g / cm 3 ~0.7g / cm 3} , as long as it is within the range porosity of 38% to 90%, the thermal conductivity of the heat insulating coating film 0.08 W / (M · k) or less can be ensured, and the film thickness is as thin as 30 mm or less, ensuring heat insulation equivalent to or better than that of a conventional insulation structure using an insulator, and excellent in light weight, and has cracks, cracks, etc. Stable heat insulation performance is ensured with a coating film strength that does not cause any problems. In other words, stable heat insulation performance can be obtained by coexistence of heat insulation and light weight and coating film strength.

  As described above, the heat insulating paint composition of the above embodiment is a heat insulating paint composition for a floor panel applied to a vehicle floor panel (floor panel main body 21), and includes a silicone resin and hollow particles. Containing and blending hollow particles in a range of 8.1 parts by weight to 26.7 parts by weight with respect to 100 parts by weight of the silicone resin.

According to the heat insulating paint composition of the above embodiment, since the base material is a silicone resin, it has high heat resistance that can withstand high heat from the exhaust pipe 30, and the floor panel body 21 made of a steel plate or the like. Adhesiveness to the surface is good, and a heat insulating coating film exhibiting high heat insulating properties can be formed by the low thermal conductivity of the silicone resin and the heat insulating effect by the hollow particles.
In particular, if the amount of hollow particles is in the range of 8.1 to 26.7 parts by weight with respect to 100 parts by weight of the silicone resin, the thermal conductivity is, for example, 0.08 W / (m · k). ) The following heat insulating coating can be obtained, for example, with a thin coating thickness (dry film thickness) of 30 mm or less, heat insulation equivalent to or better than that of a conventional heat insulating structure using an insulator can be secured. Space saving is possible.

  Thus, according to the heat insulating coating composition containing the silicone resin of the predetermined composition and the hollow particles, the thermal conductivity is, for example, 0.08 W / (m) due to the low thermal conductivity of the silicone resin and the heat insulating effect by the hollow particles. K) A heat-insulating coating film having the following high heat-insulating properties and high heat resistance by silicone resin can be formed, and the heat-insulating coating film melts and deteriorates even when placed around a high-temperature heat source such as the exhaust pipe 30. The film performance such as stable heat insulation can be exhibited. Furthermore, since the thermal conductivity of the heat insulating coating is low, the temperature rise of the coating itself does not increase, so that the floor panel main body 21 can be applied even if it is applied to the inner wall surface of the floor panel main body 21 forming the floor tunnel 40. Therefore, the heat from the exhaust pipe 30 can be insulated and the temperature rise of the floor panel main body 21 can be effectively suppressed without causing thermal deterioration of the floor panel main body 21 due to a small heat load.

  And the heat insulation structure which apply | coats the heat insulation coating composition containing the silicone resin of a predetermined | prescribed mixing | blending, and a hollow particle to the inner wall surface of the floor panel main-body part 21 which forms the floor tunnel 40 (refer FIG. 2) Then, unlike the conventional heat insulation structure using an insulator (see FIG. 6), there is no gap on the surface of the floor panel main body 21, so that the floor panel main body by directly receiving convection heat transfer or hot air from the engine. The temperature rise of 21 can also be suppressed. In addition, in the heat insulation structure using the conventional insulator (see FIG. 6), the insulator is arranged with a gap between the floor panel surface, and the insulator is arranged at a distance considering the interference sound with the exhaust pipe. In contrast, a heat insulating coating composition containing a predetermined blend of silicone resin and hollow particles is applied to the inner wall surface of the floor panel main body 21 forming the floor tunnel 40 shown in FIG. In the heat insulating structure that forms the heat insulating coating, the heat insulating coating film is not brought into close contact with the floor panel main body portion 21 and a gap is not provided, and there is no need to provide a distance with the exhaust pipe 30 in consideration of interference noise. Therefore, it is possible to save the space of the heat insulating structure, the restrictions on the tunnel opening 41 of the floor tunnel 40 are reduced, and the design freedom of the floor tunnel 40 can be increased. Further, since the heat insulating coating film has high heat insulating properties, the tunnel opening 41 of the floor tunnel 40 can be reduced and space can be saved.

  Furthermore, according to the heat insulating coating composition containing the silicone resin and the hollow particles, a heat insulating coating film having high heat insulating property and high heat resistance can be formed on the surface of the floor panel main body 21 only by applying one liquid, and a conventional insulator is obtained. Since heat insulation equivalent to or better than that of the heat insulation structure using the can be secured, the number of paint design and painting man-hours can be reduced, and the heat insulation structure of the floor tunnel 40 can be easily formed. That is, the preparation of the coating agent is completed with only one liquid, and the time and labor required for the preparation of the coating agent can be reduced, and the handling is easy. Also, since only one liquid needs to be applied, the time and labor required for the application work can be reduced, automatic painting by a painting robot or the like is easy, and a great amount of time and troublesome work are not required for construction on the floor tunnel 40. . Therefore, the heat insulation structure of the floor tunnel 40 can be formed with good productivity because the cost is low.

  Thus, according to the heat insulating paint composition of the above embodiment, a heat insulating coating film having high heat resistance and heat insulating properties can be formed, and space saving of the heat insulating structure around the high temperature heat source is possible. In addition, it is possible to form a heat insulating structure with high productivity.

  In particular, as shown in Example 1 to Example 3 above, when the silicone resin of the heat insulating coating composition of the above embodiment is an addition-type silicone resin, the floor panel body 21 made of a steel plate or the like to be coated is used. A heat-insulating coating film having elasticity and flexibility that can follow thermal expansion and contraction caused by temperature changes can be formed. Therefore, cracks, cracks, wrinkles and the like of the heat insulating coating film are prevented, and a stable heat insulating performance of the coating film can be obtained.

  Moreover, as shown in the said Example 1 thru | or Example 3, when the hollow particle of the heat insulation coating material composition of the said embodiment is a resin microballoon, it is excellent in the lightweight property (low specific gravity) of a heat insulation coating film. Furthermore, heat resistance and elasticity are also high. In particular, in a thermoplastic resin microballoon in which an inorganic powder such as calcium carbonate is coated on the shell surface made of a thermoplastic resin as used in Examples 1 to 3, a coating material is used. It has excellent elasticity and pressure resistance that is difficult to break even by shearing force during preparation, etc., can stably secure a predetermined porosity in the heat insulating coating and exhibit a stable heat insulating effect, and control heat insulating performance To make it easier. Furthermore, the strength and flexibility of the coating film against tension and bending of the coating film can be further increased.

  And according to the heat-insulating coating composition of the above-described embodiment, the heat-insulating property can be improved without lowering the coating workability by further containing the thermally expandable microcapsules and / or the foaming agent. . In other words, if a large amount of hollow particles are blended in the silicone resin, the viscosity and fluidity of the paint are lowered, so that the blending amount is limited in terms of coating workability and coating properties. Although there is a limit to the improvement of heat insulation properties, in addition to hollow particles, thermal expansion microcapsules and / or foaming agents are used in combination to ensure coating workability and coatability, and heat insulation of the coating film. It is possible to increase the sex.

  Thus, the heat-expandable microcapsule or foaming agent used in combination with the hollow particles for improving heat insulation is preferably 20 parts by weight or less with respect to 100 parts by weight of the silicone resin from the viewpoint of film forming properties. More preferably, if it is 15 parts by weight or less, and more preferably 13 parts by weight or less, it is possible to achieve both high heat insulation and coating strength. When both the thermally expandable microcapsule and the foaming agent are used, the total amount of the thermally expandable microcapsule and the foaming agent is preferably 25 parts by weight or less with respect to 100 parts by weight of the silicone resin.

  Moreover, it is preferable that the heat insulating coating composition of the said embodiment has the viscosity in the range of 1 Pa.s / 25 degreeC or more and 1000 Pa.s / 25 degreeC or less. If the viscosity of the composition is too low, sagging may occur when it is applied to the floor panel body 21 and thick coating cannot be performed. On the other hand, even if the viscosity of the composition is too high, the coating workability is lowered. If the viscosity of the heat insulating coating composition of the above embodiment is in the range of 1 Pa · s / 25 ° C. or higher and 1000 Pa · s / 25 ° C. or lower, the coating workability is good without causing problems such as sagging. Thus, automatic application by a robot capable of shortening the process time is also possible.

  In particular, according to the experimental study of the present inventor, the floor panel body made of a steel plate or the like preferably has a viscosity of the heat insulating coating composition of 10 Pa · s / 25 ° C. or higher, more preferably 30 Pa · s / 25 ° C. or higher. The adhesion of the coating film to the part 21 is excellent, and the cured coating film is also difficult to peel off. In addition, the adhesion of the coating film to the floor panel main body 21 is increased, and hot air from the engine does not enter between the surface of the floor panel main body 21 and the coating film. For this reason, high heat insulation performance is stably obtained, and the temperature rise suppressing effect of the floor panel main body 21 is enhanced. Furthermore, preferably, if the viscosity of the heat-insulating coating composition is as low as 500 Pa · s / 25 ° C. or less, the coating workability is excellent, and the process time can be shortened.

  Moreover, the heat insulating coating film obtained by applying the heat insulating coating composition of the above embodiment to the floor panel main body 21 and curing is formed by containing the hollow particles 12 and 13B in the silicone resin 11, It is formed on the surface of a vehicle floor panel (floor panel body 21).

  According to the heat insulating coating film of the above embodiment, since the silicone resin 11 contains the hollow particles 12 and 13B, the silicone resin 11 can ensure high heat resistance that can withstand high heat from the exhaust pipe 30, and Further, the adhesiveness and adhesion to the surface of the floor panel body 21 made of steel plate and the like are good, and the low thermal conductivity of the silicone resin 11 and the heat insulation by the hollow particles 12, 13B, for example, the thermal conductivity is 0.08W. / (M · k) or less high heat insulation effect can be exhibited. In particular, since the silicone resin 11 has high heat resistance, even when it is placed around a high-temperature heat source such as the exhaust pipe 30, the heat-insulating coating does not melt and heat deteriorate, and stable coating performance such as heat insulation is achieved. Demonstrate. Further, since the thermal conductivity of the heat insulating coating film is low, the temperature rise of the coating film itself does not increase, so that even if a coating film is formed on the tunnel inner wall surface of the floor panel body portion 21 forming the floor tunnel 40, the floor panel Without increasing the heat load on the main body 21 and causing the floor panel main body 21 to be thermally deteriorated, high temperature from the exhaust pipe 30 can be insulated to effectively suppress the temperature rise of the floor panel main body 21.

  And in the heat insulation structure (refer FIG. 2) which forms the heat insulation coating film which consists of the silicone resin 11 and the hollow particles 12 and 13B in the tunnel inner wall surface of the floor panel main-body part 21 which forms the floor tunnel 40 in this way, it is a conventional insulator. Unlike the heat insulation structure using the structure (see FIG. 6), no gap is provided on the surface of the floor panel main body 21, so that the temperature of the floor panel main body 21 is increased by receiving convection heat transfer or hot air directly from the engine. It can also be suppressed. In addition, in the heat insulation structure using the conventional insulator (see FIG. 6), the insulator is arranged with a gap between the floor panel surface, and the insulator is arranged at a distance considering the interference sound with the exhaust pipe. In contrast, in the heat insulating structure in which a heat insulating coating is formed on the inner wall surface of the floor panel main body 21 that forms the floor tunnel 40 shown in FIG. 2, the heat insulating coating is brought into close contact with the floor panel main body 21. There is no need to provide a gap, and it is not necessary to provide a distance with the exhaust pipe 30 in consideration of interference noise. Therefore, it is possible to save the space of the heat insulating structure, the restrictions on the tunnel opening 41 of the floor tunnel 40 are reduced, and the design freedom of the floor tunnel 40 can be increased. Further, since the heat insulating coating film has high heat insulating properties, the tunnel opening 41 of the floor tunnel 40 can be reduced and space can be saved.

  In addition, the heat-insulating coating film containing the silicone resin 11 and the hollow particles 12 and 13B formed on the surface of the floor panel only by application of one liquid of a heat-insulating coating composition containing a silicone resin and a thermoplastic resin microballoon, Because it has high heat insulation and heat resistance, it can ensure heat insulation equivalent to or better than the heat insulation structure using conventional insulators with a single layer, and multiple application liquids that require labor for preparation and construction of the application liquid Unlike the composite layer using, the heat insulating structure of the floor tunnel 40 can be formed with high productivity. That is, according to the heat insulating coating film including the hollow particles 12 and 13B in the silicone resin 11 as described above, the heat insulating structure having high heat insulating property and heat resistance and using the conventional insulator only by the heat insulating coating film. Therefore, it is easy to form the heat insulating structure of the floor tunnel 40 and the cost can be reduced.

  In this way, it is possible to save the space of the heat insulating structure around the high-temperature heat source with high heat resistance and heat insulating properties, and the heat insulating coating film can be formed with high productivity.

  In particular, as shown in Example 1 to Example 3 above, when the silicone resin 11 constituting the heat insulating coating film of the above embodiment is an addition type silicone resin, the floor panel body portion made of a steel plate or the like to be applied Thus, a heat-insulating coating film having elasticity and flexibility that can follow the thermal expansion and contraction caused by the temperature change of 21 can be formed. Therefore, cracks, cracks, wrinkles and the like of the heat insulating coating film are prevented, and a stable heat insulating performance of the coating film can be obtained.

  In addition, as shown in Examples 1 to 3, when the hollow particles 12 and 13B included in the heat insulating coating of the above embodiment are resin microballoons, the light weight (lower specific gravity) of the heat insulating coating is obtained. ). Furthermore, heat resistance and elasticity are also high. In particular, in a thermoplastic resin microballoon in which an inorganic powder such as calcium carbonate is coated on a shell surface made of a thermoplastic resin as used in Examples 1 to 3, the pressure resistance is high. Excellent in elasticity and elasticity, can ensure a predetermined porosity in the heat insulating coating, can exhibit a stable heat insulating effect, and can easily control the heat insulating performance. Furthermore, the strength and flexibility of the coating film against tension and bending of the coating film can be further increased.

  And as for the heat insulation coating film of the said embodiment, the inside of the range whose thermal conductivity is 0.03 W / (m * K)-0.08 W / (m * K) is preferable, and thermal conductivity is 0.03 W /. In the heat insulating coating film in the range of (m · K) to 0.08 W / (m · K), the dry film thickness is, for example, a thin film thickness of 30 mm or less, equivalent to a heat insulating structure using a conventional insulator. The above heat insulating properties can be secured and the effect of suppressing the temperature rise of the floor panel is high, the space saving effect of the heat insulating structure is high, and the light weight is also excellent. In particular, when a large amount of thermoplastic resin microballoon 12 or the like is blended with silicone resin 11 in a paint for forming a heat-insulating coating film, the viscosity and fluidity of the paint decrease. The blending amount is limited from the viewpoint of applicability, and the thermoplastic resin microballoon 12 alone has a limit in improving the heat insulation, but in addition to the thermoplastic resin microballoon 12 etc., the bubbles 14B are formed. By using the foaming agent 13 in combination, it is possible to improve the heat insulating property of the coating film while ensuring the coating workability and the coating property. Therefore, the heat insulating coating containing the bubbles 14 in addition to the hollow particles 12 and 13B. In the film, higher heat insulation is obtained. Moreover, in the thing containing the bubble 14B, a lightweight effect becomes high.

  Furthermore, the heat insulation coating film of the said embodiment has the preferable film thickness within the range of 0.1 mm-30 mm. If the film thickness of the heat insulating coating is in the range of 0.1 mm to 30 mm, a desired heat insulating effect is obtained, the space restriction of the tunnel opening 41 is reduced, and the coatability is good and the light weight is excellent. .

  And the said embodiment is taken as invention of the floor panel 20 for vehicles by which the heat insulation layer 10 which contains the hollow particles 12 and 13 in the silicone resin 11 was formed with respect to the surface of the floor panel main-body part 21 of a vehicle. You can also.

  According to the vehicle floor panel 20 of the above embodiment, the heat insulating layer 10 containing the hollow particles 12 and 13B in the silicone resin 11 is formed on the surface of the floor panel body 21 of the vehicle. The silicone resin 11 of the heat insulating layer 10 can ensure high heat resistance that can withstand high heat from the exhaust pipe 30, and has good adhesion and adhesion to the surface of the floor panel body 21 made of steel plate, etc. Due to the low thermal conductivity of the resin 11 and the heat insulating properties of the hollow particles 12 and 13B, for example, a high heat insulating effect with a thermal conductivity of 0.08 W / (m · k) or less can be exhibited. In particular, since the silicone resin 11 has high heat resistance, even when the heat insulating layer 10 is formed around a high-temperature heat source such as the exhaust pipe 30, the heat insulating layer 10 does not melt and is not thermally deteriorated, so that the heat insulating property is stable. Performance. Furthermore, since the heat conductivity of the heat insulating layer 10 is low, the temperature rise of the heat insulating layer 10 itself does not increase, so that even if the heat insulating layer 10 is formed on the tunnel inner wall surface of the floor panel main body 21 that forms the floor tunnel 40. Without causing the floor panel main body 21 to thermally deteriorate, high temperature from the exhaust pipe 30 can be insulated to effectively suppress the temperature rise of the floor panel main body 21.

  And in the heat insulation structure (refer FIG. 2) which forms the heat insulation layer 10 which consists of the silicone resin 11 and the hollow particles 12 and 13B in the tunnel inner wall surface of the floor panel main-body part 21 which forms the floor tunnel 40 in this way, it is a conventional insulator. Unlike the heat insulation structure using the structure (see FIG. 6), no gap is provided on the surface of the floor panel main body 21, so that the temperature of the floor panel main body 21 is increased by receiving convection heat transfer or hot air directly from the engine. It can also be suppressed. In addition, in the heat insulation structure using the conventional insulator (see FIG. 6), the insulator is arranged with a gap between the floor panel surface, and the insulator is arranged at a distance considering the interference sound with the exhaust pipe. In contrast, in the heat insulating structure in which the heat insulating layer 10 is formed on the inner wall surface of the floor panel main body 21 that forms the floor tunnel 40 shown in FIG. 2, the heat insulating layer 10 is brought into close contact with the floor panel main body 21. There is no need to provide a gap, and it is not necessary to provide a distance with the exhaust pipe 30 in consideration of interference noise. Therefore, it is possible to save the space of the heat insulating structure, the restrictions on the tunnel opening 41 of the floor tunnel 40 are reduced, and the design freedom of the floor tunnel 40 can be increased. Further, since the heat insulating layer 10 has high heat insulating properties, the tunnel opening 41 of the floor tunnel 40 can be reduced and space can be saved.

  In addition, since the heat insulation layer 10 containing the silicone resin 11 and the hollow particles 12 and 13B has high heat insulation and heat resistance, the heat insulation is equivalent to or better than a heat insulation structure using a conventional insulator with a single layer alone. Unlike the composite layer formed by using a plurality of coating liquids that require troublesome preparation and construction of the coating liquid, the heat insulating structure of the floor tunnel 40 can be formed with high productivity. That is, according to the heat insulating layer 10 including the hollow particles 12 and 13B in the silicone resin 11 as described above, the heat insulating structure having high heat insulating properties and heat resistance and using the conventional insulator only by the heat insulating layer 10. Therefore, it is easy to form the heat insulating structure of the floor tunnel 40 because the design man-hour and the coating man-hour for forming the heat insulating structure can be reduced. Cost is also low.

  In this way, the heat insulating layer 10 having high heat resistance and heat insulating property enables the space saving of the heat insulating structure around the high temperature heat source, and enables the formation of the heat insulating structure with high productivity. It becomes.

  In particular, as shown in Examples 1 to 3, when the silicone resin 11 constituting the heat insulating layer 10 of the vehicle floor panel 20 of the above embodiment is an addition type silicone resin, the floor is made of a steel plate or the like. Since it has elasticity and flexibility that can follow the thermal expansion and contraction caused by the temperature change of the panel main body 21, cracks, cracks, wrinkles and the like in the heat insulating layer 10 are prevented, and stable heat insulating performance can be obtained.

  As shown in Examples 1 to 3, when the hollow particles 12 and 13B included in the heat insulating layer 10 of the vehicle floor panel 20 of the above embodiment are resin microballoons, Excellent in lightness (low specific gravity). In particular, the thermoplastic resin microballoon in which the shell surface made of the thermoplastic resin used in Examples 1 to 3 is coated with inorganic powder such as calcium carbonate has excellent pressure resistance and elasticity, and the heat insulating layer 10 In this case, it is possible to stably secure a predetermined porosity and exhibit a stable heat insulation effect, and to easily control the heat insulation performance. Furthermore, the strength and flexibility of the heat insulating layer 10 against pulling and bending can be further increased.

  Further, the heat insulating layer 10 of the vehicle floor panel 20 of the above-described embodiment preferably has a thermal conductivity in the range of 0.03 W / (m · K) to 0.08 W / (m · K). In the heat insulating layer 10 having a rate of 0.03 W / (m · K) to 0.08 W / (m · K), the thickness is, for example, a thin thickness of 30 mm or less, and a conventional insulator is used. The heat insulation property equivalent to or better than the conventional heat insulation structure can be secured, the effect of suppressing the temperature rise of the floor panel is high, the space saving effect of the heat insulation structure is high, and the light weight is also excellent. In particular, when the heat insulating layer 10 is formed by application of a paint, if a large amount of thermoplastic resin microballoon 12 or the like is added to the silicone resin 11 in the paint, the viscosity and fluidity of the paint decrease. However, there is a limit to the blending amount from the viewpoint of coating workability and coating property, and there is a limit to the improvement of the heat insulating property only with the thermoplastic resin microballoon 12 or the like, but in addition to the thermoplastic resin microballoon 12 or the like, the bubbles 14B In combination with the hollow particles 12 and 13B, the bubbles 14 are contained because the heat-insulating property of the coating film can be improved while ensuring the coating workability and the coating property by using together the foaming agent 13 for forming In the heat insulating coating film formed, higher heat insulating properties can be obtained. Moreover, in the thing containing the bubble 14B, a lightweight effect becomes high.

  Furthermore, it is preferable that the heat insulation layer 10 of the vehicle floor panel 20 of the above-described embodiment has a thickness in the range of 0.1 mm to 30 mm. If the thickness of the heat insulation layer 10 is in the range of 0.1 mm to 30 mm, a desired heat insulation effect is obtained, the restriction of the tunnel space of the tunnel opening 41 is reduced, and the light weight is also excellent.

  In the above-described embodiment, a tunnel-like floor panel main body portion 21 projecting toward the vehicle compartment side above the vehicle body along the longitudinal direction of the vehicle body, and an opening is formed on the lower side of the vehicle body of the floor panel main body portion 21. An exhaust pipe 30 housed in the tunnel opening 41, and a heat insulation formed on the inner wall surface of the tunnel of the floor panel main body 21 around the exhaust pipe 30 and containing the hollow particles 12, 13B in the silicone resin 11. The invention can also be understood as an invention of a vehicle floor tunnel 40 structure including the layer 10.

  According to the vehicle floor tunnel 40 structure of the above-described embodiment, the floor panel main body portion 21 that protrudes toward the passenger compartment side above the vehicle body along the longitudinal direction of the vehicle body and has a tunnel shape opens toward the vehicle body lower side. Since the heat insulating layer 10 containing the hollow particles 12 and 13B in the silicone resin 11 is formed on the inner wall surface of the tunnel around the exhaust pipe 30 accommodated in the formed tunnel opening 41, the heat insulating layer 10 High heat resistance that can withstand high heat from the exhaust pipe 30 can be secured by the silicone resin 11, and the adhesiveness and adhesion to the surface of the floor panel main body 21 made of a steel plate and the like are good. Due to the heat conductivity and the heat insulation properties of the hollow particles 12 and 13B, for example, a high heat insulation effect with a heat conductivity of 0.08 W / (m · k) or less can be exhibited. In particular, since the silicone resin 11 has high heat resistance, even when the heat insulating layer 10 is formed around a high-temperature heat source such as the exhaust pipe 30, the heat insulating layer 10 does not melt and is not thermally deteriorated, so that the heat insulating property is stable. Performance. Furthermore, since the heat conductivity of the heat insulating layer 10 is low, the temperature rise of the heat insulating layer 10 itself does not increase, so that even if the heat insulating layer 10 is formed on the tunnel inner wall surface of the floor panel main body 21 that forms the floor tunnel 40. Without causing the floor panel main body 21 to thermally deteriorate, high temperature from the exhaust pipe 30 can be insulated to effectively suppress the temperature rise of the floor panel main body 21.

  And in the heat insulation structure (refer FIG. 2) which forms the heat insulation layer 10 which consists of the silicone resin 11 and the hollow particles 12 and 13B in the tunnel inner wall surface of the floor panel main-body part 21 which forms the floor tunnel 40 in this way, it is a conventional insulator. Unlike the heat insulation structure using the structure (see FIG. 6), no gap is provided on the surface of the floor panel main body 21, so that the temperature of the floor panel main body 21 is increased by receiving convection heat transfer or hot air directly from the engine. It can also be suppressed. In addition, in the heat insulation structure using the conventional insulator (see FIG. 6), the insulator is arranged with a gap between the floor panel surface, and the insulator is arranged at a distance considering the interference sound with the exhaust pipe. In contrast, in the heat insulating structure in which the heat insulating layer 10 is formed on the inner wall surface of the floor panel main body 21 that forms the floor tunnel 40 shown in FIG. 2, the heat insulating layer 10 is brought into close contact with the floor panel main body 21. There is no need to provide a gap, and it is not necessary to provide a distance with the exhaust pipe 30 in consideration of interference noise. Therefore, it is possible to save the space of the heat insulating structure, the restrictions on the tunnel opening 41 of the floor tunnel 40 are reduced, and the design freedom of the floor tunnel 40 can be increased. Further, since the heat insulating layer 10 has high heat insulating properties, the tunnel opening 41 of the floor tunnel 40 can be reduced and space can be saved.

  In addition, since the heat insulation layer 10 containing the silicone resin 11 and the hollow particles 12 and 13B has high heat insulation and heat resistance, the heat insulation is equivalent to or better than a heat insulation structure using a conventional insulator with a single layer alone. Unlike the composite layer formed by using a plurality of coating liquids that require troublesome preparation and construction of the coating liquid, the heat insulating structure of the floor tunnel 40 can be formed with high productivity. That is, according to the heat insulating layer 10 including the hollow particles 12 and 13B in the silicone resin 11 as described above, the heat insulating structure having high heat insulating properties and heat resistance and using the conventional insulator only by the heat insulating layer 10. Therefore, it is easy to form the heat insulating structure of the floor tunnel 40 because the design man-hour and the coating man-hour for forming the heat insulating structure can be reduced. Cost is also low.

  As described above, the heat insulating layer 10 having high heat resistance and heat insulating property can reduce the space of the heat insulating structure around the high-temperature heat source, and can form the heat insulating structure with high productivity. It becomes a structure.

  In particular, as shown in Examples 1 to 3, when the silicone resin 11 constituting the heat insulating layer 10 of the vehicle floor tunnel 40 structure of the above embodiment is an addition-type silicone resin, it is made of a steel plate or the like. Since it has elasticity and flexibility that can follow the thermal expansion and contraction caused by the temperature change of the floor panel main body 21, cracks, cracks, wrinkles and the like are prevented by the heat insulating layer 10, and stable heat insulating performance can be obtained.

  As shown in Examples 1 to 3, when the hollow particles 12 and 13B included in the heat insulating layer 10 of the vehicle floor tunnel 40 structure of the above embodiment are resin microballoons, the heat insulating layer 10 Can be reduced in weight (low specific gravity). In particular, the thermoplastic resin microballoon in which the shell surface made of the thermoplastic resin used in Examples 1 to 3 is coated with inorganic powder such as calcium carbonate has excellent pressure resistance and elasticity, and the heat insulating layer 10 In this case, it is possible to stably secure a predetermined porosity and exhibit a stable heat insulation effect, and to easily control the heat insulation performance. Furthermore, the strength and flexibility of the heat insulating layer 10 against pulling and bending can be further increased.

  Further, the heat insulating layer 10 of the vehicle floor tunnel 40 structure of the above embodiment preferably has a thermal conductivity in the range of 0.03 W / (m · K) to 0.08 W / (m · K). In the heat insulating layer 10 having a conductivity in the range of 0.03 W / (m · K) to 0.08 W / (m · K), the thickness is, for example, a thin thickness of 30 mm or less, and a conventional insulator is used. The heat insulation property equivalent to or better than the heat insulation structure used is secured, the effect of suppressing the temperature rise of the floor panel is high, the space-saving effect of the heat insulation structure is high, and the light weight is also excellent. In particular, when the heat insulating layer 10 is formed by application of a paint, if a large amount of thermoplastic resin microballoon 12 or the like is added to the silicone resin 11 in the paint, the viscosity and fluidity of the paint decrease. However, there is a limit to the blending amount from the viewpoint of coating workability and coating property, and there is a limit to the improvement of the heat insulating property only with the thermoplastic resin microballoon 12 or the like, but in addition to the thermoplastic resin microballoon 12 or the like, the bubbles 14B In combination with the hollow particles 12 and 13B, the bubbles 14 are contained because the heat-insulating property of the coating film can be improved while ensuring the coating workability and the coating property by using together the foaming agent 13 for forming In the heat insulating coating film formed, higher heat insulating properties can be obtained. Furthermore, in the thing containing the bubble 14B, a lightweight effect becomes high.

  Moreover, the heat insulation layer 10 of the floor tunnel 40 structure of the vehicle of the said embodiment has the preferable thickness within the range of 0.1 mm-30 mm. If the thickness of the heat insulation layer 10 is in the range of 0.1 mm to 30 mm, a desired heat insulation effect is obtained, the restriction of the tunnel space of the tunnel opening 41 is reduced, and the light weight is also excellent.

  In the above embodiment, the heat insulating layer 10 formed on the surface of the floor tunnel main body 21 is composed of a heat insulating coating film formed from a heat insulating coating composition containing a silicone resin and hollow particles. In carrying out the invention, for example, the heat insulating layer 10 is formed on the floor panel main body 21 by pouring a liquid material containing a predetermined silicon resin and hollow particles for forming the heat insulating layer 10 into the floor tunnel 40. Alternatively, the heat insulation layer 10 may be formed on the surface of the floor panel main body 21 by immersing the floor panel main body 21 in a liquid containing a predetermined silicon resin and hollow particles, or a predetermined silicon resin. In addition, the heat insulating layer 10 may be formed by joining a molded product such as a sheet containing hollow particles to the surface of the floor panel main body 21. Also by this, the high heat insulation effect by the heat insulation layer 10 containing the silicone resin 11 and the hollow particle 12 is acquired, and the temperature rise of the floor panel main-body part 21 can be suppressed effectively.

  In carrying out the present invention, the present embodiment is described with respect to the other components, components, materials, blending, shape, size, manufacturing method, etc. of the heat insulating coating composition, the heat insulating coating film, the floor panel 20 and the floor tunnel 40 structure. It is not limited to. The numerical values raised in the embodiment of the present invention are not all critical values, and certain numerical values indicate appropriate values suitable for implementation. It does not deny implementation.

DESCRIPTION OF SYMBOLS 10 Heat insulation layer 11 Silicone resin 12 Hollow particle 13A Thermal expansion microcapsule 13B Hollow particle 14A Foaming agent 14B Air bubble 20 Floor panel 21 Floor panel main-body part 30 Exhaust pipe 40 Floor tunnel

Claims (23)

A heat insulating paint composition for a floor panel applied to a floor panel of a vehicle,
A heat insulation for a vehicle floor panel comprising a silicone resin and hollow particles, wherein the hollow particles are blended within a range of 8.1 parts by weight to 26.7 parts by weight with respect to 100 parts by weight of the silicone resin. Paint composition.   The heat insulating paint composition for a vehicle floor panel according to claim 1, wherein the silicone resin is an addition type silicone resin.   The heat insulating paint composition for a vehicle floor panel according to claim 1 or 2, wherein the hollow particles are resin microballoons.   The heat insulating paint composition for a vehicle floor panel according to any one of claims 1 to 3, further comprising a thermally expandable microcapsule and / or a foaming agent.   The heat-insulating coating composition for vehicle floor panels according to claim 4, wherein the heat-expandable microcapsule or the foaming agent is blended in an amount of 20 parts by weight or less based on 100 parts by weight of the silicone resin. A heat insulating coating formed on the surface of a vehicle floor panel,
A heat insulating coating film comprising hollow particles in a silicone resin.   The heat insulating coating film according to claim 6, wherein the silicone resin is an addition type silicone resin.   The heat insulating coating film according to claim 6 or 7, wherein the hollow particles are resin microballoons.   Furthermore, the heat insulation coating film as described in any one of Claim 6 thru | or 8 which contains a bubble in the said silicone resin.   The thermal insulation coating has a thermal conductivity of 0.03 W / (m · K) or more and 0.08 W / (m · K) or less, according to any one of claims 6 to 9. Insulation coating described in 1.   The heat insulating coating film according to any one of claims 6 to 10, wherein the heat insulating coating film has a thickness in a range of 0.1 mm to 30 mm.   A vehicle floor panel, wherein a heat insulating layer containing hollow particles in a silicone resin is formed on a surface of a vehicle floor panel main body.   The vehicle floor panel according to claim 12, wherein the silicone resin of the heat insulating layer is an addition type silicone resin.   The vehicle floor panel according to claim 12 or 13, wherein the hollow particles of the heat insulating layer are resin microballoons.   The vehicle floor panel according to any one of claims 12 to 14, further comprising bubbles in the silicone resin of the heat insulating layer.   The thermal insulation layer has a thermal conductivity of 0.03 W / (m · K) or more and 0.08 W / (m · K) or less, according to any one of claims 12 to 15. Vehicle floor panel as described.   The vehicle floor panel according to any one of claims 12 to 16, wherein the heat insulation layer has a thickness in a range of 0.1 mm to 30 mm. A floor panel main body portion that protrudes toward the passenger compartment side above the vehicle body along the longitudinal direction of the vehicle body and has a tunnel shape;
An exhaust pipe housed in a tunnel formed in the lower side of the vehicle body of the floor panel body portion; and
A vehicle floor tunnel structure comprising: a heat insulating layer formed on the inner wall surface of the tunnel of the floor panel main body portion around the exhaust pipe and made of silicone resin containing hollow particles.   The vehicle floor tunnel structure according to claim 18, wherein the silicone resin of the heat insulating layer is an addition-type silicone resin.   The vehicle floor tunnel structure according to claim 18 or 19, wherein the hollow particles of the heat insulating layer are resin microballoons.   21. The vehicle floor tunnel structure according to any one of claims 18 to 20, wherein the silicone resin of the heat insulating layer contains air bubbles.   The thermal insulation layer has a thermal conductivity of 0.03 W / (m · K) or more and 0.08 W / (m · K) or less, according to any one of claims 18 to 21. The vehicle floor tunnel structure described.   The vehicle floor tunnel structure according to any one of claims 18 to 22, wherein the heat insulating layer has a thickness in a range of 0.1 mm to 30 mm.

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