Silicone resin coatings, structural components and structures

Abstract

The present invention provides a silicone resin coating film that functions as a non-combustible material, a structural component, and a structure. [Solution] A silicone resin coating film formed from a cured product of a room-temperature curable organopolysiloxane composition is applied to an object to be coated. The room-temperature curable organopolysiloxane composition contains (A) an organopolysiloxane as a base polymer having a viscosity of 100 to 500,000 mPa·s at 23°C, and (B) an inorganic substance as an inorganic filler. The (A) base polymer has siloxane bonds, which are inorganic components, and organic groups, which are organic components. For 100% by mass of the (A) base polymer, the siloxane bond content is 59% by mass or more, and the organic group content is 41% by mass or less.

Description

[Technical Field]

[0001] The present invention relates to a silicone resin coating film, a structural component, and a structure. [Background technology]

[0002] A variety of silicone resin coating films, which are cured products of silicone resin compositions, have been proposed. For example, there are many silicone resin compositions used in silicone resin coating films that cure at room temperature and crosslink into a three-dimensional network structure, and these compositions are widely used in various industrial fields.

[0003] For example, room-temperature-curable organopolysiloxane compositions, which are an example of silicone-based resin compositions, readily cure at room temperature through a condensation reaction between a hydrolyzable group bonded to a silicon atom and a hydroxyl group. Therefore, they are less susceptible to curing inhibition by impurities that arise in the curing phenomenon caused by a hydrosilylation reaction, and are therefore widely used as building materials, including exterior wall paints and roof paints.

[0004] According to Article 136-2-5, Paragraph 1, Item 13 (b) of the Enforcement Order of the Building Standards Act, buildings located within the area of ​​a disaster prevention block development plan that are not fireproof buildings, etc. or semi-fireproof buildings, etc. must have roofs made of or covered with non-combustible materials.

[0005] Therefore, for buildings that fall under this regulation, non-combustible materials must be used in the construction of their roofs, and it is therefore preferable that the roof paints and coatings used on the roofs are also non-combustible materials.

[0006] Regarding non-combustible materials, it is stipulated that they must conform to the technical standards set forth in the Enforcement Order of the Building Standards Act in terms of non-combustible performance (meaning that they will not burn due to the heat of a normal fire, and other performances set forth in the Enforcement Order of the Building Standards Act), and must be specified by the Minister of Land, Infrastructure, Transport and Tourism or certified by the Minister of Land, Infrastructure, Transport and Tourism (Article 2, Item 9 of the Building Standards Act).

[0007] Furthermore, the non-combustible performance and technical standards for non-combustible materials are stipulated in Article 108-2 of the Enforcement Order of the Building Standards Act, and the evaluation required for the examination for certification by the Minister of Land, Infrastructure, Transport and Tourism regarding non-combustible performance (Article 68-25 of the same Act) is to be carried out by the Building Materials Testing Center, a general incorporated foundation, which is a designated performance evaluation organization (Article 77-56 of the same Act), in accordance with the "Fire Prevention and Evaluation Service Manual."

[0008] For these reasons, when organopolysiloxane compositions are used as non-flammable materials in roof coatings, they must comply with the evaluation based on the "Fire Resistance Performance Testing and Evaluation Procedures Manual" of the Building Materials Testing Center, a general incorporated foundation. However, it appears that there has never been a case in the past where a coating using a cured product of a room-temperature curable organopolysiloxane composition has been evaluated and certified as a non-flammable material.

[0009] Organopolysiloxane compositions are known to be used as coating agents for electrical or electronic components due to their excellent heat resistance, electrical properties, and adhesive properties.

[0010] Conventionally, when organopolysiloxane compositions are used as coating agents for electrical or electronic components, they are often required to be flame retardant for safety reasons. For this reason, a technique has been proposed in which a platinum compound and an inorganic filler are blended into an organopolysiloxane composition to enhance flame retardancy (see Patent Documents 1 to 3).

[0011] In particular, inorganic fillers containing aluminum hydroxide are known to function well as flame retardancy improvers because the water of crystallization of aluminum hydroxide has a high heat-absorbing effect.

[0012] Therefore, it appears that the use of such a flame retardancy improver can enable the room temperature curable organopolysiloxane composition to function as a non-flammable material. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Japanese Patent Application Publication No. 4-18451 [Patent Document 2] Japanese Patent Application Publication No. 5-125285 [Patent Document 3] Japanese Patent Application Publication No. 5-230376 Summary of the Invention [Problem to be solved by the invention]

[0014] However, with the cured product of the organopolysiloxane composition described above, when the cured product of the organopolysiloxane composition contains aluminum hydroxide as a flame retardancy improver, the crystal water of the aluminum hydroxide gradually disappears even at temperatures of 200°C or lower, resulting in a problem of reduced heat resistance of the cured product.

[0015] Furthermore, when a cured product of the organopolysiloxane composition is used at high temperatures, there is a possibility that water vapor will be generated from the aluminum hydroxide contained in the cured product. In such cases, bubbles will be generated from the cured product of the organopolysiloxane composition, resulting in a poor appearance of the cured product, as well as a decrease in the waterproofness and moisture resistance of the cured product, which will also result in a decrease in the mechanical strength of the cured product.

[0016] Incidentally, recent work style reforms to improve working conditions have essentially required a cap of eight hours on overtime work for workers and the introduction of a two-day weekend system for various workers, including painters. As a result, the painting industry, which is involved in building and construction sites, is also facing an even more serious labor shortage.

[0017] Furthermore, in the painting industry today, the aging of painting craftsmen and the shortage of young craftsmen to take over are becoming more serious issues, and the labor shortage is becoming an even more serious problem throughout the industry. There is a strong demand for long-lasting coating films that can simplify the painting process and reduce the number of repaintings, so that painting work can be easily carried out in a shorter time with fewer people.

[0018] In the painting industry, there are a wide variety of objects to be painted, but generally, in order to prevent or suppress rust, water leakage, and other deterioration of the objects or parts thereof, their surfaces are coated with corrosion-resistant (including salt damage-resistant), waterproof, and other protective coatings, and such coatings are repainted periodically at specified intervals.

[0019] Examples of objects to be painted include structures such as buildings and structures, for example, metal roofs, concrete flat roofs, bridges (bridges with steel girders and other parts; the same applies below), steel towers and their components, as well as undercarriage parts such as the chassis of automobiles, agricultural machinery, railways, and other vehicles.

[0020] The roofs of buildings and other structures are ideal spaces for installing power equipment, air conditioning outdoor units, and other equipment required for the use and operation of such structures, and are therefore commonly used for installing solar power generation equipment with solar panels, cubicle-type high-voltage power receiving equipment, outdoor units and cooling towers for indoor air conditioning equipment, elevated water tanks, antennas, advertising towers, signs, and other structures.

[0021] However, in the case of roofs where such various types of equipment are installed, there are cases where the presence of these various types of equipment gets in the way when repainting the roof, making it impossible to carry out the repainting sufficiently and appropriately.

[0022] For example, it is generally said that solar panels can generate electricity for about 20 to 30 years, while the output guarantee period set by solar panel manufacturers is generally 20 to 25 years. Based on these factors, the actual replacement cycle for solar panels is thought to be around 25 years.

[0023] In contrast, the metal roof on which the solar panels are installed is a building material used for Melting The lifespan of galvanized steel sheets is said to be about 10 to 20 years, and it is said that they can be used for even longer by periodically repainting the surface coating every 5 to 10 years. Hot-dip galvanized steel sheets include, for example, unpainted hot-dip galvanized steel sheets and pre-painted hot-dip galvanized steel sheets (including pre-coated metals that have been painted at the steel sheet manufacturing factory).

[0024] As such, the repainting cycle for metal roofs is shorter than the replacement cycle for solar panels. Therefore, once solar panels have been installed on a metal roof, any subsequent repainting of the metal roof must be done either by repainting a portion of the roof while leaving the solar panels in place and avoiding the installed area, or by removing the fixing brackets that secure the solar panels to the roof and temporarily removing the solar panels from the metal roof, and then repainting the entire roof.

[0025] Naturally, when repainting a metal roof, it is more preferable to temporarily remove the solar panels from the metal roof and then repaint the entire roof. However, temporarily removing and reinstalling the solar panels requires additional work such as removing and reinstalling the fixing brackets and transporting the solar panels, which makes the entire painting work more complicated and requires additional manpower, construction time, and construction costs.

[0026] Furthermore, if solar panels are temporarily removed after being installed on a roof, they may no longer be covered by free repair guarantees offered by solar panel manufacturers, etc., so it is not possible to simply remove installed solar panels from a metal roof and repaint the roof.

[0027] For this reason, repair paint is often applied to only parts of the roof excluding the areas where the solar panels are installed, rather than the entire roof. However, if the solar panels are left installed on the roof, if the installed areas rust or leak, it is not possible to repaint these areas, which creates the problem that the roof cannot be adequately waterproofed or rust-proofed.

[0028] In particular, in addition to the recent spread of solar power generation equipment, the installation of solar panels on newly constructed homes in Tokyo has also become mandatory, so there is also the problem that it is predicted that the number of metal roofs on which solar panels are installed will increase more than ever in the future.

[0029] Next, for flat roofs with concrete surfaces, waterproofing is applied to the surface to prevent water leakage, and such waterproofing includes, for example, waterproofing in which a polyvinyl chloride waterproofing sheet is laid and fixed to the roof surface (hereinafter also referred to as "polyvinyl chloride waterproofing"), waterproofing in which an asphalt waterproofing sheet is adhesively fixed to the roof surface (hereinafter also referred to as "asphalt waterproofing"), waterproofing in which a urethane resin paint is applied (hereinafter referred to as "urethane waterproofing"), etc. These polyvinyl chloride waterproofing, asphalt waterproofing, and urethane waterproofing are widely used because they are inexpensive, can have a thicker waterproof layer than waterproofing using rubber sheets, and are superior in weather resistance.

[0030] The waterproofing properties of these concrete flat roofs deteriorate over time. For example, the lifespan of vinyl chloride waterproofing is said to be about 10 to 20 years, that of asphalt waterproofing about 12 to 25 years, and that of urethane waterproofing about 8 to 15 years. However, the lifespan of these waterproofing materials can be extended by periodically repainting their surfaces with repair paints such as waterproof top coats at intervals shorter than their lifespan.

[0031] The lifespan of the top coats used in these waterproofing works is generally less than 10 years regardless of the type, so the repainting cycle for the top coats of the various waterproofing works mentioned above is said to be generally 5 to 10 years, although this varies depending on the type of base polymer of the top coat.For example, if the base polymer is a urethane-based resin paint, it is said to be about 5 to 7 years, if it is a polyester-based resin paint, it is said to be about 5 to 7 years, and if it is a fluorine-based resin paint, it is said to be about 10 years.

[0032] While the lifespan of vinyl chloride waterproofing is approximately 20 years, that of asphalt waterproofing is 25 years, and that of urethane waterproofing is 15 years, the top coats used on these waterproofing materials must be repainted at least every five years. This means that the top coats will need to be repainted many times before the lifespan of the various waterproofing materials mentioned above expires. Furthermore, repainting the top coat over the entire roof requires the temporary removal and reinstallation of various pieces of equipment, which requires additional work to temporarily remove and reinstall the various pieces of equipment, making the entire painting work more complicated and resulting in additional manpower, construction time, and construction costs.

[0033] Furthermore, in recent years, temperatures have tended to rise due to climate change caused by global warming, creating severe conditions that impair the weather resistance of top coats, making it easier for resin-based top coats to deteriorate and creating an environment in which the top coat reapplication cycle becomes even shorter.

[0034] Next, metal structures such as steel towers and bridges have constituent parts made of metal materials, and if the metal surfaces of these constituent materials are left exposed, they will corrode and deteriorate quickly, leading to collapse.In order to prevent such corrosion and deterioration, the metal surfaces of the constituent materials are protected by painting them with a coating.

[0035] For example, metal structures such as steel towers and bridges generally have their metal surfaces coated with a heavy-duty anticorrosion coating, which is periodically repainted. This heavy-duty coating is carried out, for example, by blasting the metal surface, painting the metal surface with zinc-rich paint to provide a base anticorrosion treatment, applying a primer coat of polyurethane-based resin paint or epoxy-based resin paint thereon, applying an intermediate coat of polyurethane-based resin paint, epoxy-based resin paint, or fluorine-based resin paint that matches the components of the primer and top coat to ensure adhesion between the primer and top coat, and then applying a top coat of polyurethane-based resin paint, epoxy-based resin paint, fluorine-based resin paint, or the like that has excellent weather resistance to prevent deterioration of the primer and intermediate coat films due to ultraviolet rays, etc.

[0036] The repainting cycle for such heavy-duty corrosion-resistant coatings varies depending on the environment in which the metal structures being coated, such as bridges and steel towers, are used. For example, in coastal areas, where the structures are susceptible to salt damage, the repainting cycle is said to be about every 10 years; in cold regions, where cracks are likely to occur due to repeated freezing and thawing in winter, the repainting cycle is about every 10 years; and on bridges with heavy traffic, where the paint is subject to damage from friction and wear, the repainting cycle is said to be about every 5 years.

[0037] Even for steel towers and bridges that have been coated with such heavy-duty corrosion-resistant paint, repainting is required many times, at intervals of 10 years or less. Therefore, there is a need for a paint that has a longer repainting cycle, which can reduce the frequency of repainting the metal surface, and also for a paint film that can simplify the painting work.

[0038] Next, the undercarriage of a vehicle such as an automobile (hereinafter referred to as "vehicle undercarriage") includes, for example, various parts provided on the underside of the vehicle, such as the chassis, undercover, drive shaft, muffler, wheel housing, and various parts attached to or provided in the vicinity of these parts or locations, and is easily exposed to rainwater and melted snow from the road surface while driving, and is particularly susceptible to rust due to the effects of chloride ions contained in snow-melting agents.

[0039] For painting such undercarriage parts of a vehicle (hereinafter referred to as "vehicle undercarriage painting"), bitumen-based paints, chassis black, and other undercoat paints (hereinafter simply referred to as "undercoat paints") are widely used. Here, undercoat paints are used to apply an anti-rust coating film to the chassis and other undercarriage parts of a vehicle to provide corrosion resistance (also referred to as corrosion resistance, corrosion resistance, or rust prevention; the same applies below) and prevent rust from forming on the metal surface. However, the repainting cycle for such anti-rust coating films is short, about 1 to 2 years, and frequent repainting is required.

[0040] This vehicle undercarriage painting is carried out using, for example, water-based or oil-based acrylic resin paint, but the exhaust ducts, including the muffler, located in the vehicle undercarriage, become very hot due to the exhaust heat from the engine, so they require separate painting using heat-resistant paint.

[0041] Furthermore, since stones on the road surface can bounce off and hit the underside of the vehicle while the vehicle is moving, damaging the vehicle, areas that are particularly susceptible to stone chipping require separate coating with scratch-resistant protective paint to protect the areas and prevent damage.

[0042] For example, the inside of an automobile's wheel well is a location that is susceptible to stones flying from the road surface as the wheels rotate, and so in order to prevent damage from direct collisions with such stones, it is necessary to apply a very thick protective coating, such as a rubbery, uneven chipping coat, and provide protection with that protective coating.

[0043] In light of these points, vehicle underbody paint must at least have corrosion resistance to prevent corrosion and other deterioration of the vehicle's underbody, scratch resistance (also called scratch resistance (including chipping resistance); the same applies below) to prevent chipping of the vehicle's underbody due to flying stones and the like, and non-flammability (including heat resistance; the same applies below) and heat insulation so that the paint will not cause a decrease in performance even when applied to high-temperature parts such as mufflers. Therefore, in the past, three different types of paint were used for each part to be painted, which created the problem of making the painting process extremely complicated.

[0044] Furthermore, it is recommended that the undercarriage of these vehicles be repainted very frequently, roughly every one to two years. Repainting the total number of vehicles in Japan would be extremely cumbersome, and the painting industry, which is short of personnel, would not be able to handle all of this in the future. Therefore, there is a strong need to use paints with even longer repainting cycles, thereby significantly reducing the frequency of repainting the undercarriage of vehicles and the number of painting personnel required.

[0045] The present invention has been made to solve the above-mentioned problems, and aims to provide a silicone-based resin coating that not only functions as a non-combustible material but also exhibits weather resistance, heat insulation, corrosion resistance, and scratch resistance, taking into account the usage environment of the structure or component material to be coated, and that can further extend the repainting cycle compared to conventional coatings, thereby reducing the frequency of painting work, further simplifying the repainting work, and contributing to a reduction in the number of painting personnel required, as well as a structural component coated with such a silicone-based resin coating, and a structure having such a silicone-based resin coating. [Means for solving the problem]

[0046] To achieve this object, the silicone resin coating film of the present invention is formed from a cured product of a room-temperature-curable organopolysiloxane composition that is applied to an object to be coated. The room-temperature-curable organopolysiloxane composition contains (A) an organopolysiloxane as a base polymer having a viscosity of 100 to 500,000 mPa·s at 23°C, and (B) an inorganic substance as an inorganic filler. The (A) base polymer has siloxane bonds, which are inorganic components, and organic groups, which are organic components. The (A) base polymer contains siloxane bonds at a content of 59% by mass or more and organic groups at a content of 41% by mass or less, relative to 100% by mass of the (A) base polymer. The (B) inorganic filler is present in an amount of 100 to 150 parts by mass relative to 100 parts by mass of the (A) base polymer. The room-temperature-curable organopolysiloxane composition is applied to an object to be coated in a smooth manner at a coating weight of 600±60 g / m. 2 More than 800±80g / m 2 The cured product of the room-temperature-curable organopolysiloxane composition has inorganic siloxane bonds with an elastically stretchable rubber structure formed by crosslinking the organopolysiloxane base polymer (A) into a three-dimensional network structure.

[0047] The silicone resin coating film of the second invention is measured in accordance with "4.9.2 Heat Generation Test" in the "Fire Resistance Performance Testing and Evaluation Procedure Manual" (revised April 1, 2023) of the General Incorporated Foundation Building Materials Testing Center, and is measured by radiating 50 kW / m from a radiant electric heater to the surface of the cured product. 2 In a heat generation test using radiant heat, the total heat generated in 20 minutes after heating started was 8MJ / m 2 In the heat generation test, there are no cracks or holes penetrating to the back surface that are harmful to fire prevention within 20 minutes after heating begins, and in the heat generation test, the heat generation rate within 20 minutes after heating begins is 200 kW / m or more continuously for 10 seconds or more. 2 It shall not exceed.

[0048] The structural component of the third invention is a component used on the exterior and / or interior of a structure that is the object to be painted, and is provided with a silicone-based resin coating film according to claim 1 or 2 formed on the surface of the component.

[0049] The structure of the fourth invention comprises a component that will be a part or member on the exterior and / or interior of the structure to be painted, and a silicone-based resin coating film according to claim 1 or 2 formed on the surface of the component.

[0050] According to the silicone resin coating film of the present invention, the cured product of the room-temperature curable organopolysiloxane composition that forms the coating film can be heated to a temperature of 50 kW / m2 from a radiant electric heater on the surface of the cured product, as measured in accordance with "4.9.2 Heat Generation Test" in the "Fire Resistance Testing and Evaluation Procedure Manual" (revised April 1, 2023) of the Japan Testing Center for Building Materials. 2 In the heat generation test in which radiant heat is irradiated, the material satisfies the following evaluation criteria, and therefore functions effectively as a non-combustible material. <Evaluation criteria for pyrogenicity test> The product must satisfy all of the following criteria (1) to (3) within 20 minutes of starting heating in the heat generation test. (1) Total calorific value is 8MJ / m 2 The following is the result. (2) There are no cracks or holes that penetrate to the back surface and are detrimental to fire prevention. (3) The heat generation rate is 200 kW / m for 10 seconds or more. 2 does not exceed.

[0051] Therefore, the silicone resin coating of the present invention can impart non-flammability to the object to be painted (including structures and their constituent materials; the same applies below), so if the object to be painted is a constituent material of a structure or the structure itself, non-flammability can also be imparted to these structures.

[0052] Furthermore, according to the results of the weather resistance evaluation test described below, the silicone resin coating of this invention can exhibit weather resistance for approximately 28 years, so by applying this coating to the surface of the object to be coated, it is possible to impart long-term weather resistance to the object.

[0053] Furthermore, the cured product of the room-temperature curable organopolysiloxane composition that forms the silicone resin coating film of this invention has a rubber structure with elasticity and stretchability, in which the base polymer of component (A) in the composition is crosslinked into a three-dimensional network structure through a crosslinking reaction, and the room-temperature curable organopolysiloxane composition can be smoothly applied to the object to be coated in an amount of 600±60 g / m. 2 More than 800±80g / m 2 Since the coating is applied in a thick layer of less than 1000 μm, by forming the coating film on the surface of the object to be coated, in addition to the long-term weather resistance of the coating film, it is possible to impart long-term waterproofing, conformability, and scratch resistance to the object to be coated.

[0054] Furthermore, according to the results of evaluation tests on heat insulation and corrosion resistance described below, the silicone resin coating film of the present invention exhibits heat insulation and corrosion resistance, so by applying this coating film to the surface of the object to be coated, it is possible to impart long-term heat insulation and corrosion resistance to the object to be coated, in addition to the long-term weather resistance of the coating film. [Effects of the Invention]

[0055] The silicone resin coating film of the present invention, the components having the coating film, and the structures having the components having the coating film are non-flammable and also exhibit long-term weather resistance. In combination with this long-term weather resistance, they are able to exhibit heat insulation, corrosion resistance, and scratch resistance over the long term. This means that the repainting cycle can be extended even further compared to conventional coating films, which results in a reduction in the frequency of painting work, making the repainting work simpler and contributing to a reduction in the number of painting personnel required. [Brief explanation of the drawings]

[0056] [Figure 1] FIG. 1 is a cross-sectional view of a cured product of the room-temperature-curable organopolysiloxane composition of this example and a substrate. [Figure 2] 1 is a flowchart illustrating a method for applying a room-temperature-curable organopolysiloxane composition according to an embodiment of the present invention. [Figure 3] FIG. 1 is a schematic diagram of a test device for a heat generation test. [Figure 4] An explanatory diagram of the specimen holder and the clamping frame, where (a) is a top view of the specimen holder, (b) is an end view along line BB in (a), (c) is a top view of the clamping frame, and (d) is an end view along line DD in (c). [Figure 5] An explanatory diagram of a heat-shielding test, in which (a) is a schematic diagram of the test equipment (example equipment) for a test specimen (example test specimen) using a painted metal roof building material to which Example 1 above is applied, and (b) is a schematic diagram of the test equipment (comparison equipment) for a comparative example test specimen (comparison test specimen) using an unpainted metal roof building material. [Figure 6] 1 is a graph showing the results of measuring outdoor air temperatures at the installation locations of the example device and the comparative example device. [Figure 7] 1 is a graph showing the measurement results of the surface temperatures on the upper surfaces of the example test specimens and the comparative example test specimens. [Figure 8] 10 is a graph showing the results of measuring indoor air temperatures in the enclosed spaces of the example device and the comparative example device. [Figure 9] 8 is a graph showing the difference in surface temperature between the example specimen and the comparative example specimen shown in FIG. 7. [Figure 10] 9 is a graph showing the indoor air temperature difference between the example device and the comparative example device shown in FIG. 8. [Figure 11] 1 is a graph showing the range of temperature change in the surface temperature of the example test specimen and the comparative test specimen within one day (daytime). [Figure 12]These are front views of the test surfaces of test specimens after salt spray cycle testing, where (a) is an undamaged test specimen after 720 hours of salt spray cycle testing, (b) is an undamaged test specimen after 840 hours of salt spray cycle testing, (c) is a damaged test specimen after 720 hours of salt spray cycle testing, and (d) is a damaged test specimen after 840 hours of salt spray cycle testing. [Figure 13] This is a standard diagram showing the condition where the size of the paint film swelling is grade 2. In terms of the amount (density) of swelling of the paint film, (a) shows grade 2, (b) shows grade 3, (c) shows grade 4, and (d) shows grade 5. [Figure 14] This is a standard diagram showing the condition where the size of the paint film swelling is grade 3. In terms of the amount (density) of swelling of the paint film, (a) shows grade 2, (b) shows grade 3, (c) shows grade 4, and (d) shows grade 5. [Figure 15] This is a standard diagram showing the condition where the size of the paint film swelling is grade 4. In terms of the amount (density) of swelling of the paint film, (a) shows grade 2, (b) shows grade 3, (c) shows grade 4, and (d) shows grade 5. [Figure 16] This is a standard diagram showing the condition where the size of the paint film swelling is grade 5. In terms of the amount (density) of swelling of the paint film, (a) shows grade 2, (b) shows grade 3, (c) shows grade 4, and (d) shows grade 5. [Figure 17] This is a standard diagram for the rust grade of paint film, and in terms of the Ri grade of rust of paint film, (a) shows grade Ri1, (b) shows grade Ri2, (c) shows grade Ri3, (d) shows grade Ri4, and (e) shows grade Ri5. DETAILED DESCRIPTION OF THE INVENTION

[0057] The silicone resin coating film of the present invention will be described below with reference to embodiments, including the cured product of the room-temperature-curable organopolysiloxane composition that forms the coating film, and the room-temperature-curable organopolysiloxane composition before curing.

[0058] The silicone resin coating film of this embodiment (hereinafter also referred to as "the coating film") is formed from a cured product of a room-temperature-curable organopolysiloxane composition, and in this document, the room-temperature-curable organopolysiloxane composition is also referred to as "the composition," and the cured product of the room-temperature-curable organopolysiloxane composition is also referred to as "the cured product" or "the cured product of the composition."

[0059] In addition, in this document, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits. The content of each component in this invention indicates the content relative to the solid content unless otherwise specified.

[0060] The present composition and the present cured product are used to form a present coating film that protects the object to be coated. The present coating film is used on structures or products (also simply referred to as "structures") or their parts or other constituent materials (also simply referred to as "components") that are or are likely to deteriorate due to outdoor environments exposed to sunlight, wind and rain, or other external factors, and is useful for forming a coating film that protects the structure or its constituent materials.

[0061] The structure and its constituent materials are not particularly limited in terms of material or type, and for example, it goes without saying that all metals are applicable, but it may also be all resins and other non-ferrous metals. Note that the above-mentioned "structure" refers to the "structure" in this device, and the above-mentioned "constituent material" refers to the "constituent material" in this device.

[0062] Here, the concept of a structure includes, for example, buildings, bridges, steel towers, oil tanks, gas tanks, chimneys, windmills, parabolic antennas, plant equipment, and other real estate, as well as movable property such as automobiles, trains, ships, and other transportation machinery (especially including their undercarriage).

[0063] Furthermore, as described herein, the present composition and the present cured product not only exhibit excellent effects, particularly in terms of non-flammability, but also exhibit extremely excellent effects in terms of weather resistance, heat insulation, corrosion resistance, and scratch resistance, taking into account the evaluation results of various tests described below, and function effectively as a protective means (protective means) for structures and their parts used in environments where these performance properties are required. Therefore, the present composition and the present cured product have uses for non-flammability, weather resistance, heat insulation, corrosion resistance, or scratch resistance of structures or their parts, or for two or more of these purposes.

[0064] <Silicone resin coating (main coating)> The present coating film, which is a silicone-based resin coating film of this embodiment, is formed from a cured product of a room-temperature curable organopolysiloxane composition that is applied to an object to be coated.

[0065] The cured product of this room-temperature-curable organopolysiloxane composition has inorganic siloxane bonds with an elastically stretchable rubber structure formed by crosslinking the organopolysiloxane base polymer (A) into a three-dimensional network structure.

[0066] Here, the room-temperature-curable organopolysiloxane composition for the present coating film before curing contains an organopolysiloxane having a viscosity of 100 to 500,000 mPa s at 23°C as the base polymer of component (A) described below. This room-temperature-curable organopolysiloxane composition also contains an inorganic substance as the inorganic filler of component (B) described below.

[0067] In 100% by mass of this room-temperature-curable organopolysiloxane composition, the content of the base polymer of component (A) is 40 to 50% by mass, and the content of the inorganic filler of component (B) is 50 to 60% by mass. In other words, the content of the inorganic filler of component (B) is 100 to 150 parts by mass per 100 parts by mass of the base polymer of component (A) of the composition.

[0068] The base polymer of component (A) has siloxane bonds, which are inorganic components, and organic groups, which are organic components. Preferably, the base polymer of component (A) contains siloxane bonds at a content of 59% by mass or more and organic groups (e.g., methyl groups) at a content of 41% by mass or less, based on 100% by mass of the base polymer.

[0069] Furthermore, the room temperature curable organopolysiloxane composition is applied smoothly to the object to be coated in an amount of 600±60 g / m 2 More than 800±80g / m 2 It is painted as follows:

[0070] <Room-temperature-curable organopolysiloxane composition> Next, the room temperature curable organopolysiloxane composition used in the present coating film will be described below.

[0071] The room-temperature-curable organopolysiloxane composition has excellent non-flammability, weather resistance, heat insulation properties, corrosion resistance, and scratch resistance, and is primarily composed of a base polymer (A) that has liquid or paste-like fluidity. In addition to this base polymer, additional components include an inorganic filler (B), a crosslinking agent (C), a condensation curing catalyst (D), a diluent (E), a heat resistance improver (F), and an adhesion improver (G).

[0072] The heat resistance improver (component (F)) of the present composition is a type of inorganic filler (component (B)) and is added to the present composition as an additional component to the inorganic filler. Furthermore, when the present composition and the present cured product are to be colored, a pigment component of the desired color may be added as appropriate in addition to the main components and additive components described above.

[0073] [Component (A)] <Base polymer: room temperature curing organopolysiloxane> Component (A) functions as the base polymer (main component polymer) of the composition. It is a room-temperature curable organopolysiloxane whose molecular chain ends are blocked (capped) with organic groups such as hydroxyl groups, and has a viscosity of 100 to 500,000 mPa·s at 23°C.

[0074] The viscosity of component (A) is set within the above range because, at 23°C, if it is less than 100 mPa s, the elongation of the cured rubber will be too low to withstand practical use, and if it exceeds 500,000 mPa s, the extrudability of the composition will decrease.

[0075] The molecular structure of such room-temperature-curable organopolysiloxanes is not particularly limited to those described above, and may be, for example, linear, partially branched linear, branched, cyclic, or dendritic (three-dimensional network) structures. In particular, diorganopolysiloxanes whose main skeleton is essentially composed of repeating diorganosiloxane units and whose molecular chain terminals are blocked with organic groups such as hydroxyl groups are preferred.

[0076] Although component (A) is preferably a hydroxyl-terminated diorganopolysiloxane, it is more preferable for the component (A) to be a different organopolysiloxane containing up to 41% by weight of organic groups bonded to the molecular chain that are monovalent hydrocarbon groups containing up to about 60 carbon atoms, but this amount may be, for example, 30 to 50% by weight.

[0077] More specifically, the viscosity of the hydroxyl-terminated organopolysiloxane of component (A) is preferably 500 to 20,000 mPa·s at 23°C, and most specifically, 1,000 to 15,000 mPa·s at 23°C is more preferably.

[0078] The organic group in component (A) (including the organic group R in general formula (1) and general formula (2) below; the same applies hereinafter) is preferably a monovalent hydrocarbon group, such as an alkyl group containing 1 to 8 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or octyl; an alkenyl group such as vinyl, propenyl (allyl), or other; a cyclic alkyl group (cycloalkyl group) such as cyclopentyl or cyclohexyl; a monocyclic aryl group such as phenyl, naphthyl, tolyl, xylyl, methylphenyl, or ethylphenyl; or a fluoroalkyl group such as 3,3,3-trifluoropropyl.

[0079] More specifically, an example of the hydroxyl-terminated organopolysiloxane of component (A) is represented by the following general formula (1): HO(R2SiO) n H (1) (In formula (1), R represents a substituted or unsubstituted monovalent hydrocarbon group, and when there are two or more Rs, the Rs may be the same or different from one another, and n represents a value that provides a viscosity at 23°C in the range of 100 to 500,000 mPa·s, preferably 500 to 20,000 mPa·s, and even more preferably 1,000 to 15,000 mPa·s.)

[0080] In the above formula (1), examples of R, which is a substituted or unsubstituted monovalent hydrocarbon group, can be selected from the group described above.

[0081] Specifically, the majority of R's are alkyl groups containing 1 to 8 carbon atoms, and it is preferred that at least 50 mol % of the total number of R's are alkyl groups, more specifically 75 mol % or more, and most specifically 90 mol % or more. Furthermore, the alkyl groups used for R's are preferably methyl groups, ethyl groups, or phenyl groups, and most preferably methyl groups.

[0082] Here, when there are two or more R's in the above formula (1), they may be the same or different, i.e., the R's in formula (1) may be the same or different. However, when different R's are present in formula (1), the proportions of the various R's are not particularly limited, but from the viewpoints of ease of synthesis of component (A), the mechanical properties of the composition after curing, and the balance of the viscosity of the uncured composition, it is more preferable that 90 mol % or more of the R's be methyl groups, and if all or some of the R's in the above formula (1) are organic groups other than methyl groups, it is preferable that the organic groups other than methyl groups be vinyl groups or phenyl groups.

[0083] However, since the molecular structure of the room-temperature-curable organopolysiloxane composition is most preferably a straight-chain, hydroxyl-terminated diorganopolysiloxane in which the main chain is essentially composed of repeating diorganosiloxane units and both molecular chain terminals are blocked with hydroxyl groups, in such cases the organic group for R is particularly preferably a methyl group, and as a result, a more preferred specific example of component (A) is a hydroxyl-terminated dimethylpolysiloxane.

[0084] In this way, when component (A), the main component of the room-temperature-curable organopolysiloxane composition, is a hydroxyl-terminated dimethylpolysiloxane, the organic group bonded to its side chain is a methyl group, which has the fewest carbon atoms of all alkyl groups. This reduces the total number of carbon atoms remaining in the cured product of this composition, and therefore, when the cured product of this composition is exposed to combustion, the combustion calories that serve as an internal fuel source in this cured product are reduced, which enhances its non-flammability (including flame retardancy; the same applies below) function.

[0085] Furthermore, the cured product formed by curing this composition is a product in which the base polymer of component (A) is crosslinked into a three-dimensional network structure through a crosslinking reaction, resulting in increased hardness and mechanical strength (including tensile strength and tear strength; the same applies below). As a result, this cured product can be endowed with high non-flammability, corrosion resistance, weather resistance, and cold resistance.

[0086] Here, if the content of component (A) in the composition is excessive, the amount of organic matter that separates from component (A) and is generated in the cured product obtained by curing the composition will increase, reducing the non-flammability of the cured product of the composition; and the content of the inorganic filler of component (B), described below, will be relatively insufficient, reducing the hardness and tensile strength of the cured product.

[0087] On the other hand, if the content of component (A) in the composition is insufficient, the mechanical strength and hardness of the cured product obtained by curing the composition will decrease, or the viscosity of the entire composition will be insufficient to obtain a viscosity suitable for coating work, resulting in a decrease in the dry film thickness of the cured product after curing, and the non-flammability, corrosion resistance, weather resistance, and cold resistance will be insufficient.Furthermore, the elongation of the cured product will be reduced, resulting in a decrease in its ability to follow substrate deformation.

[0088] For this reason, the content of component (A) in the present composition is more preferably 40 to 50% by mass relative to 100% by mass of the present composition.

[0089] [(B) Component] <Inorganic filler: calcium carbonate powder> Component (B) is a calcium carbonate powder that functions as an inorganic filler. When added to the base polymer, this component (B) enhances the hardness, tensile strength, and other mechanical strengths of the cured product of this composition.

[0090] The powder material of the inorganic filler of component (B) is calcium carbonate, and one or more powders of heavy calcium carbonate such as ground calcium carbonate, light calcium carbonate, precipitated calcium carbonate such as colloidal calcium carbonate, can be selected and used, either the same or different types. Among these, it is more preferable to use a powder of colloidal calcium carbonate alone.

[0091] The calcium carbonate powder of component (B) is preferably surface-treated by coating the particle surface with an organic substance such as an organic acid or a resin acid, and particularly preferably surface-treated with a fatty acid, and most particularly preferably surface-treated with stearic acid.

[0092] By subjecting the calcium carbonate powder (B) to such a fatty acid surface treatment, its dispersibility can be improved, and this prevents application defects that would occur when the composition is applied, such as when the powdered calcium carbonate forms balls and the cured product becomes uneven after the composition hardens, resulting in an uneven film thickness. Calcium carbonate that has been subjected to such a fatty acid surface treatment or stearic acid surface treatment is called fatty acid surface-treated calcium carbonate or stearic acid surface-treated calcium carbonate.

[0093] Here, if the content of calcium carbonate powder, which is the inorganic filler (B) in the composition is excessive, the viscosity of the composition will increase, making it unsuitable for coating work and resulting in a decrease in the dry film thickness of the composition and a decrease in the elongation of the cured product, resulting in a decrease in its ability to follow substrate deformation. On the other hand, if the content of component (B) in the composition is insufficient, the content of component (A) in the composition will increase relatively, and the organic matter that separates from component (A) will increase relatively in the cured product, resulting in a decrease in the non-flammability of the cured product and a decrease in the hardness and tensile strength of the cured product.

[0094] For this reason, the content of component (B) in the present composition is more preferably 50 to 60% by mass relative to 100% by mass of the present composition.

[0095] [(C) component] <Crosslinking agent: silane compound or its partial hydrolyzate> Component (C) is a silane compound or a partial hydrolyzate thereof having two or more (preferably three or more) hydrolyzable groups bonded to silicon atoms in each molecule, and functions as a crosslinking agent for the composition. Specifically, organoalkoxysilane or a partial hydrolyzate thereof is more preferred.

[0096] In other words, component (C) promotes the crosslinking reaction of the hydroxyl-terminated organopolysiloxane, component (A). An example of a silane compound that functions as a crosslinking agent for component (C) is one represented by the following general formula (2): Ra Si(OR) 4-a (2) (In formula (2), R is a substituted or unsubstituted monovalent hydrocarbon group, and when there are two or more Rs, they may be the same or different, and a is 0, 1, or 2. R is as defined in formula (1) above.)

[0097] In the above formula (2), examples of the substituted or unsubstituted monovalent hydrocarbon group R are the same as those explained for "R" in the general formula (1) of the above component (A).

[0098] As in the case of the above formula (1), also in the above formula (2), R may be the same or different types may be mixed, and when different types of R are mixed, the ratio of each type of R is not particularly limited.

[0099] Specific examples of specific compounds within the scope of formula (2) include methyltrimethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, and tetraethoxysilane. One or more compounds are selected from the group consisting of the above. Among these, methyltrimethoxysilane is most suitable as the organoalkoxysilane crosslinking agent of component (C).

[0100] If the content of the crosslinking agent (C) in the composition is excessive, the composition will be prone to oil separation, which will require the trouble of stirring the composition again before use to mix and disperse the separated oil layer. On the other hand, if the content of the crosslinking agent in the composition is insufficient, the liquid surface of the composition will harden during storage, making it more likely to form a cured product, and stability over time will be reduced.

[0101] [(D) component] <Condensation curing catalyst: Titanium chelate catalyst> Component (D) is a titanium chelate catalyst that functions as a condensation curing catalyst. Component (D) is an additive component that functions as a catalyst to accelerate moisture curing of the composition at room temperature and also provides the function of improving the adhesiveness of the composition.

[0102] Specific examples of the titanium chelate catalyst of component (D) include alkoxy titaniums such as tetra(isopropoxy)titanium, tetrabutoxytitanium, partial hydrolysate of tetra(isopropoxy)titanium, and partial hydrolysate of tetrabutoxytitanium, diisopropoxybis(ethylacetoacetate)titanium, diisopropoxybis(methylacetoacetate)titanium, diisopropoxybis(acetylacetone)titanium, dibutoxybis(ethylacetoacetate)titanium, and dimethoxybis(ethylacetoacetate). Examples of suitable titanium chelate compounds include known titanium chelate compounds such as dibutoxybis(ethylacetoacetate)zirconium, dibutoxybis(methylacetoacetate)zirconium, dibutoxybis(acetylaceto)zirconium, butoxytris(ethylacetoacetate)zirconium, and tributoxy(ethylacetoacetate)zirconium. Among these, titanium chelate compounds are preferred due to their curing catalytic ability, and diisopropoxybis(ethylacetoacetate)titanium is particularly preferred.

[0103] If the titanium chelate catalyst of component (D) is contained in the composition in excess, the adhesiveness of the composition expected from that increased amount will saturate, and no further improvement in adhesiveness will be obtained, resulting in an increase in cost due to the increased amount. On the other hand, if the amount contained in the composition is insufficient, the liquid surface of the composition will harden during storage, making it more likely to form a cured product, reducing stability over time and reducing the adhesiveness of the composition to the substrate, making it necessary to coat the substrate with a primer before coating the composition.

[0104] [(E) component] <Diluent: low molecular weight siloxane> Component (E) is a low-molecular-weight siloxane that functions as a diluent. Component (E) is an additive that reduces the viscosity of the base polymer, the main component of the room-temperature-curable organopolysiloxane composition, thereby improving its flowability. This viscosity reduction improves the workability involved in applying the room-temperature-curable organopolysiloxane composition.

[0105] The diluent, component (E), is preferably a volatile low-molecular-weight siloxane, more preferably a highly volatile low-molecular-weight cyclic siloxane. Furthermore, among low-molecular-weight cyclic siloxanes, low-molecular-weight cyclic siloxanes such as five-membered cyclic siloxanes (pentamers (abbreviated as "D5"; the same applies hereinafter) (hereinafter referred to as "five-membered cyclic siloxanes") are most preferred because they have a high boiling point and high volatility.

[0106] Component (E) may be a combination of one or more selected from low-molecular-weight siloxane diluents, aromatic hydrocarbon solvents such as toluene and xylene, and other hydrocarbon-based solvent diluents. Alcohol-based solvents are unsuitable because they may absorb moisture into the cured product and cause oxidation of the substrate.

[0107] Furthermore, component (E) is a component that volatilizes and disappears from the cured product after the composition has cured. Therefore, if the content of component (E) is excessive, the amount of components that volatilize and disappear from the cured product increases, causing the film thickness to decrease when the cured product dries and making the composition more likely to drip when applied. On the other hand, if the content of component (E) is insufficient, the viscosity of the composition as a whole increases, making the composition less easy to work with when applied.

[0108] [Component (F)] <Heat resistance improver: Single metal compound, complex mineral compound> Component (F) is a powdered additive that functions as a heat resistance improver. Component (F) can be classified into powders of simple metal compounds such as titanium oxide, alumina, zinc oxide, and silica, and powders of complex mineral compounds consisting of aggregates of multiple simple substances and / or compounds contained in minerals such as mica, wollastonite, and talc.

[0109] As mentioned above, examples of component (F) include powders of single metal compounds such as titanium oxide, alumina (aluminum oxide), silica (silicon dioxide), and zinc oxide (zinc white), and powders of mineral complex compounds such as mica (layered silicate mineral), wollastonite (natural silicate mineral), and talc (a type of silicate mineral). One or more of these may be selected and used in combination, and most specifically, titanium oxide is more preferred.

[0110] In addition, some of the components (F) are produced by crushing natural minerals into powder. Therefore, even if the component is a single metal compound such as titanium oxide, alumina, zinc oxide, or silica, it is not necessarily a pure single metal compound, and naturally includes those containing small amounts of other substances as impurities that are different from the main metal compound.

[0111] Here, component (F) is an additive component that has the function of improving the cured product and the heat resistance of the cured product, but it also has the function of improving the weather resistance and hardness of the cured product.

[0112] Among these, titanium oxide, alumina, zinc oxide, and silica, which are single compounds of component (F), have heat-shielding properties and also function as heat-shielding property improvers. In particular, titanium oxide, alumina, and zinc oxide, which are metal oxides of component (F), have excellent refractive indexes, solar reflectances, and light scattering coefficients, although this depends on the particle size and shape, and can exhibit reflective / scattering properties against infrared rays.

[0113] In particular, titanium oxide, among the components (F), tends to have better weather resistance than alumina and zinc oxide, and is therefore able to improve the weather resistance and heat insulation properties of the cured product, making it the most specific and appropriate heat resistance improver.

[0114] This component (F) is an additive component that improves the heat resistance, weather resistance, and hardness of the cured product, and also improves the heat-shielding properties of the cured product by increasing the refractive index and light-scattering properties of the composition and the cured product against infrared rays, thereby improving the heat resistance of the cured product. This heat-shielding performance reduces the amount of heat transferred to the substrate, thereby improving the heat resistance of the cured product. Both the single metal compound and the mineral-based composite compound may be derived from natural minerals or industrially produced.

[0115] Furthermore, if the content of component (F) in the composition is excessive, the elongation of the cured product will decrease, making the cured product hard and brittle, and the viscosity of the composition will increase, reducing the workability of the composition when applied. On the other hand, if the content of component (F) in the composition is insufficient, the hardness and tensile strength of the cured product will decrease.

[0116] [(G) component] <Adhesion improver: Isocyanate-functional polyalkoxysilane> Component (G) is an isocyanate-functional polyalkoxysilane that functions as an adhesion promoter, and is an additive component that imparts a function to enhance or improve the adhesive strength of the cured product to substrates (especially inorganic materials).

[0117] Component (G) is an organofunctional polyalkoxysilane represented by the following general formula (3), which functions as an adhesion promoter.

[0118] [ka]

[0119] wherein, in the above formula (3), R1 and R2 are monovalent hydrocarbon groups containing up to about 8 carbon atoms, t is 0 to 3, and Z is a saturated, unsaturated, or aromatic hydrocarbon of up to 30 carbon atoms, specifically up to 12 carbon atoms, more specifically up to 8 carbon atoms, which hydrocarbon is further functionalized with a group selected from the group consisting of an amino group, an ether group, an epoxy group, a glycidoxy group, an isocyanate group, a cyano group, an acryloxy group, a methacryloxy group, and an acyloxy group.

[0120] Adhesion-promoting compounds within the scope of formula (3) above and suitable for use herein, and methods for preparing the same, are described, for example, in U.S. Pat. Nos. 4,483,973, 4,528,353, 3,821,218, and 4,100,129, each of which is incorporated herein by reference.

[0121] In addition to or alternatively to the compound of formula (3) above, the room temperature vulcanizable organopolysiloxane composition of the present invention includes an isocyanate-functional polyalkoxysilane which functions as an adhesion promoter.

[0122] Isocyanate-functional polyalkoxysilanes suitable for use as component (G) in room temperature curable organopolysiloxane compositions have the following general formula (4):

[0123] [ka]

[0124] In the above formula (4), G is selected from the group having the R1 group defined above (see the definition of the above formula (3)), a styryl group, a vinyl group, an allyl group, a chloroallyl group, a cyclohexenyl group, and a group represented by the following general formula (5):

[0125] [ka]

[0126] wherein in the above formula (5), R1 and R2 are as defined above (see the definition in the above formula (3)); R5 is selected from an alkylenearylene group, an alkylene group, a cycloalkylene group, and a halogenated alkylenearylene group, each of which is a divalent hydrocarbon group containing 2 to 12 carbon atoms, and b varies from 0 to 3; and in the above formula (4), R3 and R4 are each a monovalent hydrocarbon group containing up to 8 carbon atoms or a monovalent cyanoalkyl group containing up to 8 carbon atoms, R5 is as defined in the above formula (5), and b varies from 0 to 3.

[0127] Most specifically, an adhesion promoter within the scope of formula (4) above is tris[3-(trimethoxysilyl)propyl] isocyanurate (or "1,3,5-tristrimethoxysilylpropyl isocyanurate"), which can be prepared by taking the corresponding alkoxy hydride silane and reacting it with an unsaturated isocyanurate or cyanurate in the presence of a platinum catalyst, whereupon the hydride adds to the unsaturated group, e.g., the allyl group of the isocyanurate ring.

[0128] Other specific compounds within the scope of formula (4) above are selected from the group consisting of bis-1,3-trimethoxysilylpropyl isocyanurate, 1,3,5-tristrimethoxysilylethyl isocyanurate, 1,3,5-trismethyldimethoxysilylpropyl isocyanurate, and 1,3,5-trismethyldiethoxysilylpropyl isocyanurate, and combinations thereof.

[0129] If the content of the adhesion improver of component (G) is excessive, the adhesiveness of the composition expected from the increased amount will saturate, and no further improvement in adhesiveness will be obtained, resulting in an increase in cost due to the increased amount. On the other hand, if the content of the adhesion improver is insufficient, the adhesiveness of the composition to the substrate will decrease, making it necessary to apply a primer to the substrate before applying the composition.

[0130] In one non-limiting embodiment, the present composition may contain, as the adhesion improver of component (G), 1,3,5-tristrimethoxysilylpropyl isocyanurate, bis-1,3-trimethoxysilylpropyl isocyanurate, 1,3,5-tristrimethoxysilylethyl isocyanurate, 1,3,5-trismethyldimethoxysilylpropyl isocyanurate, 1,3,5-trismethyldiethoxysilylpropyl isocyanurate, n-2-aminoethyl-3-aminopropyltriethoxysilane, methacryloxypropyltrimethoxysilane, methylaminopropyltrimethoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropyltriethoxy ... The adhesion promoter may be selected from the group consisting of trimethoxysilane, gamma-glycidoxyethyltrimethoxysilane, beta-(3,4-epoxycyclohexyl)propyltrimethoxysilane, beta-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, isocyanatopropyltriethoxysilane, isocyanatopropylmethyldimethoxysilane, beta-cyanoethyltrimethoxysilane, gamma-acryloxypropyltrimethoxysilane, gamma-methacryloxypropylmethyldimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, n-ethyl-3-trimethoxysilyl-2-methylpropaneamine, and combinations thereof. [Example]

[0131] The present invention will be specifically described below by showing examples and comparative examples that are examples of the present invention. Furthermore, these examples do not limit the present invention in any way, and appropriate modifications can be made within the scope of the invention. Hereinafter, the composition will also be referred to as a "paint," and the cured product of the composition will also be referred to as a "coating film."

[0132] <Cured Product of Room-Temperature-Curable Organopolysiloxane Composition> FIG. 1 is a cross-sectional view of a cured product of the room-temperature-curable organopolysiloxane composition of this example and a substrate.

[0133] As shown in Figure 1, a cured product 1 of a room-temperature-curable organopolysiloxane composition is adhered to the surface of a substrate 2 and is laminated to form an integrated product with the substrate 2. This cured product 1 is formed by applying a room-temperature-curable organopolysiloxane composition, described below, to the surface of the substrate 2 in a predetermined thickness, drying and curing the composition, and is formed as a smooth film on the surface of the substrate 2.

[0134] The substrate 2 has a surface made of steel or other metal (also referred to simply as "metal" in this specification), and may be, for example, a steel plate or other metal plate (also referred to simply as "metal plate" in this specification), a structure with a metal surface (for example, a building or other structure, including bridges, steel towers, and other structures; the same applies in this specification), or a plate or structure with a resin surface.

[0135] The various plate materials typified by the above-mentioned base material 2 are examples of constituent materials of the present invention, and the structure typified by the above-mentioned base material 2 is an example of a structure of the present invention. In other words, the structures of the present invention include the above-mentioned buildings and other structures, as well as bridges, steel towers and other buildings, and undercarriage parts such as chassis of automobiles, agricultural machinery, railways and other vehicles, and the constituent materials of the present invention are materials used in part or all of the structure of the present invention. For example, if the structure is a building, these refer to various building materials such as roofing materials and exterior wall materials.

[0136] <Method for applying room-temperature-curable organopolysiloxane composition> Next, with reference to FIG. 2, a method for applying the room-temperature-curable organopolysiloxane composition of this embodiment, that is, a method for applying a cured product 1 of the room-temperature-curable organopolysiloxane composition to a substrate 2, will be described.

[0137] FIG. 2 is a flow chart showing the coating method for the cured product 1 of the room-temperature-curable organopolysiloxane composition of this example.

[0138] As shown in Figure 2, the method for applying a cured product 1 of a room-temperature-curable organopolysiloxane composition includes a surface preparation treatment (S1) and a coating film formation treatment (S2). The surface of the substrate 2 is preferably free of black scale, red rust, loose rust, and other oxides, as well as dust, dirt, oily substances, frost, mold, stains, and other impurities, and is preferably dry. If these oxides, impurities, or moisture are present on the surface of the substrate 2, the adhesion between the surface of the substrate 2 and the cured product 1 of this composition will be reduced.

[0139] Therefore, in this coating method, in order to remove oxides and impurities from the surface of the substrate 2, it is preferable to perform oxide removal (S11), cleaning (S12), and drying (S13) on the surface of the substrate 2 in the base preparation process (S1) before the coating film formation process (S2).

[0140] In the oxide removal step (S11), the surface of the substrate 2 is visually inspected to determine whether or not oxides are present, and if any are present, they are carefully removed using a power tool, etc. It is preferable to perform a step on the areas of the surface of the substrate 2 where no oxides are present.

[0141] Here, in this oxide removal (S11), if there is occurrence or progression of red rust or floating rust, and / or cracks or peeling on the surface of the substrate 2, these are preferably removed by type 2 or type 3 scraping. Furthermore, if there are defects such as cracks or holes on the surface of the substrate 2 (S111: Yes), it is preferable to perform repair (S112) by attaching glass cloth to the defects using a silicone caulking agent to seal the defects, and if such repair (S112) is not necessary (S111: No), then such repair (S112) is skipped and the next cleaning (S12) is performed.

[0142] In cleaning (S12), after the oxide removal (S11), in order to improve adhesion between the surface of the substrate 2 and the room-temperature-curable organopolysiloxane composition, the surface of the substrate 2 is cleaned with cleaning water sprayed at high pressure from a high-pressure washer to remove impurities from the surface of the substrate 2. In drying (S13), after the cleaning (S12), the surface of the substrate 2 is thoroughly dried to evaporate moisture from the surface of the substrate 2.

[0143] It is preferable that no moisture remain on the surface of the substrate 2. However, if there is a very small amount of moisture, the base polymer of component (A), which forms the main skeleton of the cured product 1 of the room-temperature-curable organopolysiloxane composition, is moisture-permeable and is a moisture-curing organopolysiloxane. Therefore, any moisture remaining on the surface of the substrate 2 will turn into gas and pass through the cured product 1. This gas can then be used for moisture curing, thereby preventing the surface of the substrate 2 from corroding due to the remaining moisture.

[0144] Furthermore, in the base preparation process (S1), before high-pressure cleaning, the surface of the base material 2 is visually inspected to see whether or not there is black scale or red rust thereon, and if black scale or red rust is found, it is preferable to thoroughly remove the black scale or red rust from the areas where the presence of black scale or red rust is confirmed using an electric tool or the like before high-pressure cleaning, while performing a surface preparation on the other areas.

[0145] Next, in the coating film formation treatment (S2), after the surface preparation treatment (S1), the room-temperature-curable organopolysiloxane composition is applied evenly onto the surface of the substrate 2. In this case, the composition may be applied by any of spray coating, brush coating, roller coating, or other coating methods.

[0146] This coating film formation process (S2) involves applying the composition (S21), drying the composition (S22), and determining the film thickness of the cured product 1 (S23). The processes from S21 to S23 are repeated until the film thickness of the cured product 1 reaches the specified film thickness (S23: No). When the film thickness of the cured product 1 reaches the specified film thickness (S23: Yes), the application of the cured product 1 is completed.

[0147] Here, the coating film formation process (S2) involves multiple wet-on-wet coatings of the composition (see JIS standard K5500: No. 3002), and the drying (S22) is a process of natural drying to evaporate volatile components from the cured product 1 of the room-temperature-curable organopolysiloxane composition, known as flash-off. This natural drying time is known as the flash-off time (coating interval) (see JIS standard K5500: No. 3214).

[0148] For example, in the coating film formation process (S2) of the cured product 1 of the room temperature curable organopolysiloxane composition, the composition is applied (S21) at a coating amount of 800 g / m 2 is applied in two or three separate coats, and the composition is dried (S22) with a flash-off time of 3 to 48 hours in spring and autumn, 1 to 48 hours in summer, and 4 to 72 hours in winter, and the specified film thickness in film thickness determination (S23) is preferably 500 μm (the coating thickness before drying).

[0149] The standard film thickness of 500 μm before drying is calculated using a coating amount of 800 g / m 2 In the film thickness judgment (S23), the applied amount of this composition was 800 g / m 2 However, the coating thickness before drying used to judge the coating thickness is not limited to 500 μm, and the coating amount is 600 ± 60 g / m 2 More than 800±80g / m 2 The following coating thicknesses may also be used:

[0150] <Compositions of Examples 1 and 2 and their cured products> Examples 1 and 2 are cured products of the following room-temperature-curable organopolysiloxane compositions formed by applying the compositions to the surface of a substrate. The room-temperature-curable organopolysiloxane compositions used in Examples 1 and 2 each contain the above-mentioned base polymer (A), inorganic filler (B), crosslinking agent (C), condensation curing catalyst (D), diluent (E), heat resistance improver (F), and adhesion improver (G).

[0151] The present composition has the property that its viscosity decreases when shear stress is applied to it and recovers when the shear stress is removed, i.e., it has thixotropy (also called thixotropy; the same applies hereinafter). Note that, since the present composition has thixotropy, its viscosity is measured by a viscosity measurement method using a rotational viscometer.

[0152] Here, the viscosity of the composition is measured using a viscosity measurement method using a single-cylinder rotational viscometer (see methods for measuring viscosity of liquids (JIS Z8803:2011 "9. Method for measuring viscosity using a single-cylinder rotational viscometer" and "Plastics - Liquid, emulsion or dispersion resins - Method for measuring apparent viscosity using a rotational viscometer" (JIS Standard K7117-1:1999 "Appendix B (Regulations) Principles, explanations and characteristics of viscometers A, B and C types")), a so-called B-type viscometer.

[0153] Specifically, the viscosity of this composition was measured using a TVB-10 Brookfield viscometer manufactured by Toki Sangyo Co., Ltd., with a No. 5 spindle and a spindle rotation speed of 4 rpm (revolutions per minute). According to this viscosity measurement, the viscosity of this composition (at a temperature of 23°C) was approximately 12,000 mPa·s (poises).

[0154] This room-temperature-curable organopolysiloxane composition is colored whitish due to the addition of titanium oxide as a weather resistance improver, and as shown in Table 1 below, its solar reflectance in the near-infrared wavelength range (780 nm to 3500 nm) is as high as 85.6% (measured in a test conforming to JIS standard A5675 "High solar reflectance coating for roofs 7.8 'Solar reflectance'").

[0155] If the room-temperature-curable organopolysiloxane composition is to be colored in a color other than white, a pigment component of the desired color is added in addition to the main components and additive components described above. However, this additional pigment component is added separately from the total blending ratio of the main components and additive components, which totals 100% by mass.

[0156] [Coating conditions for Example 1] The main conditions for applying the room-temperature-curable organopolysiloxane composition of Example 1 are as follows: Temperature when painting: 23℃ Relative humidity during painting: 60%RH Total application amount (coating amount): 800g / m 2 Painting method: Wet-on-wet application (2-3 coats) Flash-off time: Allow to dry naturally for at least 4 hours and up to 72 hours after each application. Coating thickness: 500 μm (coating amount 800 g / m 2 equivalent) (coating thickness after drying)

[0157] [Coating conditions for Example 2] The main coating conditions for the room temperature curable organopolysiloxane composition of Example 2 were as follows: Temperature during painting: 23±2℃ Relative humidity during painting: 50±5%RH Total application amount (coating amount): 720g / m 2 Painting method: Wet-on-wet application (2-3 coats) Flash-off time: Allow to dry naturally for at least 4 hours and up to 72 hours after each application. Coating thickness: 430 μm (coating amount 720 g / m 2 equivalent) (coating thickness after drying) The hydroxyl-terminated organopolysiloxane used as component (A), which is the base polymer of the room-temperature-curable organopolysiloxane composition of Example 2, has a main chain of siloxane bonds of 59% by mass and an organic group content of 41% by mass.

[0158] [Comparative Example 1] Comparative Example 1 is a rubber asphalt coating film formed by applying a rubber asphalt waterproofing material to the surface of a substrate. This rubber asphalt waterproofing material is a moisture-curing material that, after being applied to the surface of a substrate, undergoes a curing reaction at room temperature to form a coating film with rubber elasticity.

[0159] This Comparative Example 1 conforms to JIS Standard A6021:2011 "Rubber asphalt-based waterproofing coating material for construction," and this rubber asphalt-based waterproofing material is made from a mixture of asphalt emulsion and synthetic rubber such as SBR. The rubber asphalt coating film using this waterproofing material conforms to the coating film thickness of 2000 μm (= 2 mm) (coating film thickness after drying) in Table 3 of the same Standard A6021:2011.

[0160] [Painting conditions for Comparative Example 1] The main coating conditions for the rubber asphalt waterproofing material of Comparative Example 1 are as follows: Temperature during application: 23±2℃ Relative humidity during application: 50±10%RH Coating thickness: 2000 μm (= 2 mm) (coating thickness after drying)

[0161] Comparative Example 2 Comparative Example 2 is a urethane rubber waterproofing material and a urethane rubber coating film formed by applying it to the surface of a substrate. This urethane rubber waterproofing material is a moisture-curing material that, after being applied to the surface of a substrate, undergoes a curing reaction at room temperature to form a coating film with rubber elasticity.

[0162] Comparative Example 2 conforms to JIS Standard A6021:2011, "Architectural Coating Waterproofing Material for Roofs, Urethane Rubber-Based, High-Strength Type." This urethane rubber waterproofing material is a urethane prepolymer obtained by reacting polyisocyanate with polyol. The urethane rubber waterproofing material is a viscous liquid base material with isocyanate groups attached to the molecular terminals, and is a paste-like liquid kneaded together with a curing agent such as an amine or polyol that reacts with the isocyanate groups, as well as fillers, plasticizers, pigments, catalysts, stabilizers, etc. The urethane rubber coating using this waterproofing material conforms to the coating thickness of 1000 μm (= 1 mm) (coating thickness after drying) in Table 3 of the same Standard A6021:2011.

[0163] [Painting conditions for Comparative Example 2] The main coating conditions for the urethane rubber waterproof material of Comparative Example 2 are as follows: Temperature during application: 23±2℃ Relative humidity during application: 50±10%RH Coating thickness: 1000 μm (= 1 mm) (coating thickness after drying)

[0164] <Performance Evaluation of Cured Products of Room-Temperature-Curable Organopolysiloxane Compositions> As described above, the cured product of the room-temperature-curable organopolysiloxane composition of this embodiment contains only a hydroxyl-terminated organopolysiloxane as the main polymer component required for coating film formation. Therefore, unlike silicone-modified acrylic polymers and silicone-modified polyurethane polymers, the main skeleton of this composition does not contain any organic groups such as acrylic or polyurethane. As a result, the cured product obtained by drying and curing this composition has excellent weather resistance and corrosion resistance, and because a heat resistance improver such as titanium oxide is also added, it also has excellent heat insulation properties.

[0165] The test results for the main properties of the cured product of the room-temperature-curable organopolysiloxane composition of Example 1 are shown in Table 1. Weather resistance (durability) will be described in detail later.

[0166] [Table 1]

[0167] <Weather resistance evaluation> [Weather resistance test: Ultra-accelerated weather resistance test] For the weather resistance evaluation, an ultra-accelerated weather resistance test was carried out for 1680 hours under the test conditions below for the above-mentioned Example 1 and Comparative Examples 1 and 2, and after the 1680 hours had elapsed, the appearance of each coating film of Example 1 and Comparative Examples 1 and 2 was evaluated based on the following criteria. Note that, since 60 hours of this test time of 1680 hours corresponds to approximately one year, this makes the total durability test equivalent to 28 years.

[0168] [Test equipment] In the weathering test, the following ultra-accelerated weathering test equipment was used. Device name: METAL-WEATHER (manufactured by Daipla Wintes Co., Ltd.) ·Model: KW-R7TP

[0169] [Test method or test conditions] The weather resistance test conditions are as follows. Lamp: Metal halide lamp KF filter: KF-1 KF filter wavelength range: 295-780nm (visible light and ultraviolet light) Black panel temperature: 80℃ ·Illuminance: 81mW / cm 2 Temperature inside the chamber during irradiation: Approximately 55°C (no temperature control) Humidity inside the chamber during irradiation: 50% RH Irradiation time: 1680 hours Spray operation: No

[0170] [Exam evaluation criteria] The weather resistance test is evaluated using two types of criteria listed in the following Tables 2 and 3. These criteria are based on JIS Standard A1439:2016, Table 5 - Criteria for Crack Quantity (Q) and Table 6 - Criteria for Crack Width (W), as well as "a) Non-directional cracks" and "b) Directional cracks" in Figure 21 - Crack scale diagram. The criteria in Table 5 of JIS Standard A1439:2016 are evaluated using Figures 21a) and b) of the same standard.

[0171] [Table 2]

[0172] [Table 3]

[0173] [Weather resistance evaluation results] As a result of the above, the results of the weather resistance tests for Example 1 and Comparative Examples 1 and 2, i.e., the results of the weather resistance evaluation, are shown in the following Table 4. According to these evaluation results, the cured product of Example 1 showed extremely good results in terms of both the amount and width of cracks with respect to weather resistance equivalent to a total of 28 years, compared to the rubber asphalt waterproofing material and the urethane rubber waterproofing material of Comparative Examples 1 and 2, confirming that this is a highly weather-resistant composition that exhibits weather resistance equivalent to a total of 28 years.

[0174] [Table 4]

[0175] <Regarding non-flammability evaluation> As described above, the cured product of the room-temperature-curable organopolysiloxane composition of this embodiment has an inorganic polysiloxane bond structure, and in addition, contains a majority of inorganic substances, namely, inorganic filler and calcium carbonate and titanium oxide, which are heat resistance improvers, with only a small amount of organic substances, resulting in high non-flammability and, as a result, preventing a decrease in the fire resistance of the substrate. [Test method: Pyrogenicity test] Here, non-combustibility is evaluated in accordance with "4.9.2 Heat Generation Test" in the "Fire Resistance Performance Testing and Evaluation Procedure Manual" (revised April 1, 2023) of the Japan Testing Center for Construction Materials. This heat generation test involves applying 50 kW / m of heat from a radiant electric heater to the surface of a cured product of a room-temperature-curable organopolysiloxane composition. 2 The total heat output for 20 minutes after the start of heating is 8MJ / m 2 (2) There are no cracks or holes that penetrate to the back surface that are harmful to fire prevention, and (3) The heat generation rate is 200 kW / m for 10 seconds or more. 2 It is required not to exceed.

[0176] The total heat release amount and heat release rate obtained in the heat release test can be reduced by relatively increasing the content of inorganic filler and relatively decreasing the content of polyorganosiloxane in the cured product of the room-temperature-curable organopolysiloxane composition of this embodiment, thereby adjusting the amount of heat release from combustion derived from the polymer.

[0177] Specifically, "4.9.2 Heat generation test" in the "Fire resistance performance test and evaluation procedure manual" (revised April 1, 2023) of the Japan Testing Center for Construction Materials shall be conducted in accordance with the test specimen, test equipment, and test conditions shown below.

[0178] [Test specimen] (1) The number of test specimens (substrates coated with a cured product of a room-temperature curable organopolysiloxane composition) shall be three. (2) The shape and dimensions of the test specimen shall be a square with each side measuring 99 mm ± 1 mm. (3) The base material of the test specimen shall be a zinc-plated steel plate with a thickness of 0.27 mm (original plate thickness). (4) Before the test, the test specimen is cured at a temperature of 23°C ± 2°C and a relative humidity of 50% ± 5% until it reaches a constant mass.

[0179] Figure 3 is a schematic diagram of the test equipment for the heat generation test, and Figure 4 is an explanatory diagram of the specimen holder 13 and the holding frame 18, where Figure 4(a) is a top view of the specimen holder 13, Figure 4(b) is an end view along line BB in Figure 4(a), Figure 4(c) is a top view of the holding frame 13, and Figure 4(d) is an end view along line DD in Figure 4(c).

[0180] [Test equipment] (1) As shown in Figures 3 and 4, the test equipment 10 used in the heat generation test includes a conical radiant electric heater 11, an electric spark plug 12, a radiant heat shield (not shown; the same applies below), a test specimen holder 13, a gas sampling device 14, an exhaust system 15 capable of measuring gas flow rate, and a heat flow meter 16. (2) Radiant electric heater 11 is 50 kW / m 2 The radiant heat must be able to be irradiated uniformly and stably onto the surface of the test piece. (3) The radiant heat shield must be capable of protecting the test specimen from radiant heat before the test begins. (4) A schematic diagram of the test holder 13 and presser frame 18 included in the test apparatus 10 is shown in Figure 5. The test specimen holder 13 has a bottom plate 13a formed in a square shape in plan view, with each side of its outer dimension L1 (= 106 mm ± 1 mm) equal to each other, and an outer peripheral plate 13b with an outer dimension of height H1 (= 25 mm ± 1 mm) attached upwardly to the periphery of the bottom plate 13a, and the bottom plate 13a and outer peripheral plate 13b are formed from stainless steel plates with a thickness t1 (= 2.4 mm ± 0.15 mm). The pressing frame 18 comprises a top plate 18a formed in a square shape in plan view with equal outer dimensions on each side L2 (=111 mm±1 mm), and an outer peripheral plate 18b with an outer dimension of height H2 (=54 mm±1 mm) that hangs downward from the outer periphery of the top plate 18a.The top plate 18a and outer peripheral plate 18b are formed from stainless steel plates with a thickness t2 (=1.9 mm±0.1 mm), and an opening 18c with a square shape in plan view and sides L3 (=94.0 mm±0.5 mm) is drilled in the center of the top plate 18a. (5) The exhaust system 15 is equipped with a centrifugal exhaust fan 15a that functions effectively at the test temperature, a hood 15b, intake and exhaust ducts 15c and 15d for the fan 15a, an orifice plate flow meter 15e, etc. The distance between the bottom end of the hood 15b and the surface of the test specimen is 210 mm ± 50 mm, and the exhaust device (centrifugal exhaust fan) 15a of the exhaust system 15 in this state has a flow rate of 0.024 m when converted to standard temperature and standard pressure. 3 The exhaust gas flow rate must be at least 1 / s. To measure the exhaust gas flow rate, an orifice plate 15f with an inner diameter of 57 mm ± 3 mm and a thickness of 1.6 mm ± 0.3 mm is installed in the exhaust ducts 15c and 15d at a position at least 350 mm ± 15 mm downstream from the fan 15a. To sample the exhaust gas, a ring sampler 14a with 12 holes, each 2.2 mm ± 0.1 mm in diameter, is attached 685 mm ± 15 mm from the hood 15b, with the holes facing in the opposite direction to the flow. The exhaust gas temperature is measured at the center of the exhaust duct 15d, 100 mm ± 5 mm upstream from the orifice plate 15f. (6) The gas sampling device 14 shall be capable of continuously and accurately measuring the concentrations of oxygen, carbon monoxide, and carbon dioxide in the exhaust gas. (7) The spark plug 12 shall be capable of receiving power from a 10kV transformer or induction coil system, etc. The distance between the electrodes of the spark plug 12 shall be 3mm±0.5mm, and the electrodes shall be positioned 13mm±2mm above the central axis of the test specimen, in principle. (8) Heat flux meter 16 is 100 kW / m 2 ±10kW / m 2 The heat flux meter 16 is a Schmidt-Boelter type that can measure up to 12.5 mm in diameter. The heat sensing part of the heat flux meter 16 is circular and has a surface emissivity of 0.95±0.05.

[0181] [Test conditions] (1) The test time shall be 20 minutes from the time when radiant heat is applied to the surface of the test specimen and an electric spark is simultaneously generated by the spark plug 12. (2) The test specimen is wrapped on the sides and back with aluminum foil of 0.025 mm or more and 0.04 mm or less in thickness, placed in a press frame, and then coated with inorganic fiber (nominal density 64 to 128 kg / m) on the back side. 3 ) and then pressed into the test specimen holder 13. The test specimen is placed so that the surface of the cured product of the room-temperature-curable organopolysiloxane composition faces the radiant electric heater 11. (3) During the test, a radiant electric heater 12 emits 50 kW / m of heat to the surface of the test specimen. 2 It emits radiant heat. (4) Exhaust gas flow rate: 0.024 m 3 Adjust to / s. (5) Until the start of the test, the test specimen is protected from radiant heat by a radiant heat shield. (6) Before moving the radiation heat shield, set the spark plug 12 in place.

[0182] [Measurement conditions] (1) Measure the oxygen concentration at intervals of no more than 5 seconds. (2) The heat generation rate per unit area q' is calculated using the following method. A (t)(kW / m 2 ) and calculate the heat generation rate per unit area q' A (t) is 200kW / m 2 The duration of a state in which the heat generation rate per unit area exceeds 200 kW / m 2 The total heat generation per unit area Q A,tot (t)(MJ / m 2 ) is the heat generation rate per unit area q' A The heat release rate (t) is calculated by trapezoidal integration over time. Here, the test time is used as the integration interval, and the integration interval is divided equally by the measurement interval. Negative heat release rates are set to 0, and only positive heat release rates are integrated.

[0183] Regarding the symbols for heat release rate and heat release rate per unit area, in "Math 5" below, the symbol "q" is written with a "·" above it so that it is called "q dot." In the main text of this document, for convenience, this will be written as "q'."

[0184] The heat release rate q'(t) is calculated by measuring the oxygen concentration and using the following equation (1).

[0185]

number

[0186] The orifice coefficient C is the oxygen analyzer reading X when methane is burned at a flow rate equivalent to the following formula (2) under a specified exhaust gas flow rate. O2 , the absolute temperature T of the gas in the exhaust duct 15d e and the differential pressure Δp of the orifice plate flowmeter 15e according to the following formula "Equation 3".

[0187]

number

[0188]

number

[0189] Oxygen analyzer reading X O2 (t) is calculated according to the following formula "Number 4".

[0190]

number

[0191] Heat generation rate per unit area q' A (t) is calculated according to the following formula (5).

[0192]

number

[0193] [Test specimen of Example 2] As described above, a heat generation test for evaluating non-flammability was carried out on the cured product of the room-temperature-curable organopolysiloxane composition of Example 2 to evaluate its non-flammability.

[0194] In the heat buildup test for the cured product of the room-temperature-curable organopolysiloxane composition of Example 2, the substrate used for forming a film of the cured product of Example 2 was a steel or metal plate conforming to Article 2, Paragraph 9 of the Building Standards Act, as exemplified in Ministry of Construction Notification No. 1400 of 2000, with no decorative surface applied.

[0195] Here, the substrate of the test specimen is the following building material for roofing. Base material: hot-dip galvanized steel sheet (JIS standard G3302 SGCC-Z18) ·Shape: Flat plate Surface shape: smooth Thickness: 0.3mm (base plate thickness 0.27mm) ·Mass: 2.36kg / m 2 (Plating weight 0.224kg / m 2 )

[0196] The cured product of the room-temperature-curable organopolysiloxane composition of Example 2 that was applied to the test specimen was as follows, as described above. Temperature during painting: 23±2℃ Relative humidity during painting: 50±5%RH Total application amount (coating amount): 720g / m 2 Painting method: Wet-on-wet application (2-3 coats) Flash-off time: Allow to dry naturally for at least 4 hours and up to 72 hours after each application. Coating thickness: 430 μm (coating amount: 720 g / m 2 equivalent) (coating thickness after drying)

[0197] The test specimen was prepared using a room-temperature-curable organopolysiloxane composition according to the present embodiment, in which the organic mass was 41 g / m 2The organic mass specified in the "Fire Resistance Testing and Evaluation Procedures Manual" (200 g / m 2 Gas toxicity testing was not conducted because the following conditions were met.

[0198] When the test specimen was subjected to a heat generation test in accordance with the above-mentioned method manual, the following favorable results were obtained.

[0199] [Non-flammable evaluation results] (1) The total heat output for 20 minutes after the start of heating is 8MJ / m 2 It was as follows. (2) For 20 minutes after the start of heating, there were no cracks or holes penetrating to the back surface that were harmful to fire prevention. (3) For 20 minutes after the start of heating, the maximum heat generation rate is 200 kW / m for 10 seconds or more. 2 did not exceed.

[0200] The results of this evaluation confirmed that the cured product of the room-temperature-curable organopolysiloxane composition can be recognized as a non-combustible material, and that this cured product is effective as a non-combustible material. In particular, for the cured product of this composition, the amount of this composition applied to the substrate was 720±72 g / m. 2 It is preferable that: <Evaluation of heat insulation properties>

[0201] Figure 5 is an explanatory diagram of the heat-shielding property test, where Figure 5(a) is a schematic diagram of a test device (hereinafter referred to as the "example device") 20 for a test specimen (hereinafter referred to as the "example test specimen") 21a using a painted metal roof building material to which Example 1 above is applied, and Figure 5(b) is a schematic diagram of a test device (hereinafter referred to as the "comparison test specimen") 31a for a comparative example test specimen (hereinafter referred to as the "comparison test specimen") 30 using an unpainted metal roof building material.

[0202] [Test equipment] As shown in Figures 5(a) and 5(b), the test equipment 20, 30 used for the heat insulation test includes a roofing material 21 using an example test piece 21a or a roofing material 31 using a comparative example test piece 31a, an enclosed space 22, 32 provided on the underside of the roofing material 21, 31, an outer wall material 23, 33 that covers the four sides of the enclosed space 22, 32, and a bottom plate material 24, 34 that is connected to the lower end of the outer wall material 23, 33 and covers the entire bottom surface of the enclosed space 22, 32, and the enclosed space 22, 32 is enclosed in all directions by these roofing materials 21, 31, outer wall materials 23, 33 and bottom plate materials 24, 34.

[0203] The test equipment 20, 30 is a simple model of a building, with the test specimens 21a, 31a, eaves doors 21b, 31b, and eaves coverings 21c, 31c imitating the roof materials 21, 31, the outer wall materials 23, 33 imitating the exterior walls, and the bottom plate materials 24, 34 imitating the ceiling material or floor material. If the bottom plate materials 24, 34 are considered to be ceiling materials, the enclosed spaces 22, 32 will be spaces that imitate attic spaces, and if the bottom plate materials 24, 34 are considered to be floor materials, the enclosed spaces 22, 32 will be spaces that imitate indoor spaces without ceilings.

[0204] The test apparatus 20 is an example of a structure of the present invention, the example test specimen 21a is an example of a constituent material of the present invention, and the cured product 21a2 of the room-temperature-curable organopolysiloxane composition is an example of a cured product of the curable organopolysiloxane composition formed on the surface of a constituent material.

[0205] Additionally, polystyrene foam insulation 25, 35 is attached to the entire inner surface of all of the outer wall materials 23, 33. This insulation 25, 35 is molded into a plate shape and is 20 mm thick. In this way, the insulation 25, 35 insulates the entire periphery of the enclosed spaces 22, 32 on all four sides, preventing the outdoor temperature from affecting the indoor temperature within the enclosed spaces 22, 32.

[0206] Both test apparatuses 20, 30 are placed on hard plastic pallets 26, 36. These pallets 26, 36 are 120 mm high, and the test apparatuses 20, 30 are supported 120 mm above the ground surface GL. By placing the test apparatuses 20, 30 on the pallets 26, 36 in this manner, the floor plates 24, 34 of the test apparatuses 20, 30 are prevented from coming into direct contact with the ground surface GL, preventing ground heat from being directly transferred to the floor plates 24, 34 and affecting the indoor air temperature within the enclosed spaces 22, 32.

[0207] In the explanation of this heat insulation test, the left-right direction in Figure 5 is referred to as the "horizontal direction," the hydraulic direction relative to the paper surface of Figure 5 is referred to as the "vertical direction," and the up-down direction in Figure 5, which is perpendicular to these horizontal and vertical directions, is referred to as the "height direction."

[0208] The test apparatuses 20 and 30 shown in Figures 5(a) and 5(b) both have a horizontal length (left-right direction in Figure 5) of 1200 mm and a vertical length (perpendicular to the paper surface in Figure 5) of 920 mm. The example apparatus 20 shown in Figure 5(a) has a height of 1120 mm, while the comparative example apparatus 30 shown in Figure 5(b) has a height of 1210 mm. Note that the test apparatuses 20 and 30 shown in Figures 5(a) and 5(b) are identical except for the example specimen 21a and the comparative example specimen 31a.

[0209] [Test specimen] As shown in FIG. 5(a), the example specimen 21a includes a single folded plate 21a1 as a base material, and a protective film 21a2 formed integrally and in a layer on the uneven upper surface (upper side of FIG. 5) of the single folded plate 21a1, which is the cured product of the room-temperature-curable organopolysiloxane composition of Example 1 described above.

[0210] As shown in FIG. 5(b), the comparative example specimen 31a is equipped with a double folded plate (double-roofing folded plate) 31a1, which is the base material. This double folded plate 31a1 is composed of two upper and lower single folded plates 31a1a and 31a1b, separated by a gap. A heat insulating material 31a2 is filled in the gap between these two single folded plates 31a1a and 31a1b. The upper single folded plate 31a1a of the double folded plate (double-roofing folded plate) 31a1 is referred to as the "top roofing material 31a1a," and the lower single folded plate 31a1b is referred to as the "under-roofing material 31a1b."

[0211] The example specimen 21a and the comparative example specimen 31a use single folded plates 21a1, 31a1a, and 31a1b of the same shape and type as the metal building material, and the metal building material is an unpainted hot-dip galvanized steel plate conforming to JIS Standard 3302: 2019. In the example specimen 21a, a cured product 21a2 of the room-temperature-curable organopolysiloxane composition of Example 1 described above is formed on one surface (top surface) of the unpainted single folded plate 21a1 made of hot-dip galvanized steel plate.

[0212] Each of the single folded plates 21a1, 31a1a, and 31a1b has a trapezoidal wave-like cross section with alternating peaks and valleys running horizontally. These single folded plates 21a1, 31a1a, and 31a1b conform to JIS Standard A6514:1995, with a peak height of 200 mm, a peak pitch of 300 mm, a working width of 600 mm, and a plate thickness of 0.8 mm. The gap between the top roofing material 31a1a and the underlayment material 31a1b of the double folded plate 31a1 is approximately 10 mm wide, and a 10 mm thick insulating material 31a2 is inserted between them.

[0213] Furthermore, since multiple trapezoidal gaps occur between the undersides of the roofing materials 21, 31, i.e., the undersides of the single folded sheet 21a1 and underlayment material 31a1b, and the outer wall materials 23, 33, in a front view, eaves doors 21b, 31b are fitted into these gaps. Furthermore, gaps that occur between the side surfaces of the roofing materials 21, 31 and the upper ends of the outer wall materials 22, 32 are blocked by eaves wrappings 21c, 31c. Furthermore, in the test equipment 20, 30, the gaps that occur are blocked by filling them with caulking material.

[0214] [Measurement conditions / method] The example device 20 using the example test specimen 21a and the comparative example device 30 using the comparative example test specimen 31a are arranged side by side in the same test location. The test location is an outdoor space where an asphalt-paved surface serves as the ground surface GL and is irradiated with sunlight SL.

[0215] The test devices 20, 30 are placed on pallets 26, 36 installed outdoors on the ground surface GL. The outdoor air temperature at the installation locations of the test devices 20, 30 is measured by thermometers 27, 37. The thermometers 27, 37 are placed on pedestals P, P, respectively, at a height of 870 mm from the ground surface GL. The thermometers 27, 37 have a temperature sensor (not shown) built into their main bodies, thermocouple sensors 27a, 37a connected via connection cables 27b, 37b, and displays 27c, 37c that display the temperatures detected by these sensors.

[0216] The thermometers 27, 37 measure the outdoor air temperature with their temperature sensors (not shown) and the indoor air temperatures of the enclosed spaces 22, 32 with their thermocouple sensors 27a, 37a. When installing the thermometers 27, 37, in order to prevent direct sunlight from irradiating the temperature sensors built into the thermometers 27, 37, the thermometers 27, 37 are covered from above with light-shielding and heat-shielding sheets 28, 38, and the area around the thermometers 27, 37 is kept well ventilated.

[0217] The example device 20 and the comparative example device 30 are each equipped with a thermometer 27, 37, which measure the outdoor air temperature, respectively. However, since the installation positions of the thermometers 27, 37 are slightly different and accurate calibration cannot be performed for each, there may be some error in the measured values ​​even when measuring the outdoor air temperature at the same test location.

[0218] The surface temperatures of the upper surfaces of the example specimen 21a and the comparative example specimen 31a were measured non-contact with infrared thermometers 29 and 39. The infrared thermometers 29 and 39 measure the surface temperatures by detecting infrared rays emitted from the cured product 21a2 of the room-temperature-curable organopolysiloxane composition of the example specimen 21a and the overlaying material 31a1a of the comparative example specimen 31a, respectively.

[0219] The surface temperature of the example specimen 21a, the outdoor air temperature of the test device 20, and the indoor temperature of the enclosed space 22, as well as the surface temperature of the roofing material 31a1a of the comparative example specimen 31a, the outdoor air temperature of the test device 30, and the indoor temperature of the enclosed space 32, were all measured simultaneously at each measurement time. These temperature measurements were taken 123 times in total, with 4 to 8 measurements per day, between 9:00 AM and 5:00 PM (excluding rainy days) on each measurement day, over 13 consecutive weekdays, including a holiday. The range in the number of measurements per day is due to the fact that the number of measurements was higher on sunny days or in certain time periods when the amount of change in each temperature tends to be large, and relatively lower on cloudy days or in certain time periods when the amount of change in each temperature tends to be small.

[0220] [Heat-shielding performance evaluation results] Figures 6 to 11 are graphs showing the test results of the heat insulation property test. Figure 6 is a graph showing the measurement results of the outdoor air temperature at the installation locations of the example device 20 and the comparative example device 30. Figure 7 is a graph showing the measurement results of the surface temperature on the upper surface of the example test specimen 20 and the comparative example test specimen 30. Figure 8 is a graph showing the measurement results of the indoor air temperature in the enclosed spaces 22, 32 of the example device 20 and the comparative example device 30. Figure 9 is a graph showing the difference in surface temperature between the example test specimen 21a and the comparative example test specimen 31a shown in Figure 7. Figures 10 and 8 are graphs showing the difference in indoor air temperature between the example device 20 and the comparative example device 30. Figure 11 is a graph showing the temperature change range within a day (daytime) of the surface temperature of the example test specimen 21a and the comparative example test specimen 31a.

[0221] 6, the outdoor air temperature remained within a range of approximately 30 to 40°C for both the example device 20 and the comparative example device 30, and approximately the same measurement values ​​were obtained at each measurement. This confirms that the example device 20 and the comparative example device 30 were placed side by side in close proximity in the same installation location, and therefore both were placed in the same outdoor environment.

[0222] As shown in Figure 7, the surface temperatures of the example specimen 21a and the comparative example specimen 31a, i.e., the surface temperatures of the cured product 21a2 of the room temperature curable organopolysiloxane composition and the surface (upper surface) of the overlaying material 31a1a that were exposed to direct sunlight, were as follows: the surface of the cured product 21a2 of the example specimen 21a fluctuated between approximately 30 and 40°C, maintaining a temperature range close to the outdoor air temperature, whereas the surface of the overlaying material 31a1a of the comparative example specimen 31a fluctuated between approximately 40 and 85°C, confirming that the temperature had risen to a temperature nearly twice as high as the outdoor air temperature.

[0223] Here, as shown in Figure 9, when the temperature difference between the surface temperature of the hardened material 21a2 of the example specimen 21a and the surface temperature of the overlay material 31a1a of the comparative example specimen 31a was calculated, it was confirmed that the surface temperature of the example specimen 21a was lower than the surface temperature of the comparative example specimen 31a by approximately -10 to -45°C, at least -8.5°C lower, and at most -46°C lower, and that the average value over all measurement points was -30.4°C lower.

[0224] Furthermore, as shown in Figure 11, the surface temperature of the comparative example specimen 31a fluctuated dramatically during the day in a range of 5 to 40°C. For example, there were days when the temperature change range within a day reached a maximum of 37.2°C, and the average daytime temperature change range over all measurement days (13 days) was found to be as high as 24.3°C. As a result, it was confirmed that the temperature change range within a day was extremely large, creating an extremely harsh usage environment for the roofing material 31.

[0225] In contrast, as shown in Figure 11, the surface temperature of the example test specimen 21a fluctuates only within a small range of 0 to 10°C during the day, with a maximum temperature change of only 9.4°C within a day. Compared to the comparative test specimen 31a, the temperature change within a day has been reduced to approximately 25%. Furthermore, the average daytime temperature change over all measurement days (13 days) was only 6.2°C, which means that the average temperature change within a day has also been reduced to approximately 25% compared to the comparative test specimen 31a, confirming that the usage environment of the roofing material 21 is extremely good.

[0226] As shown in Figure 8, it was confirmed that the indoor air temperatures of the example device 20 and the comparative example device 30 were lower at all measurement points for the example device 20 than for the comparative example device 30. Specifically, as shown in Figure 10, the indoor air temperatures of the example device 20 were at least -1°C lower, at most -4.5°C lower, and -2.7°C lower on average across all measurement points than the indoor air temperatures of the comparative example device 30. In this way, it was confirmed that when the roofing material 21 of the example test device 20 was used, the indoor air temperature was lowered compared to when the roofing material 31 of the comparative example test specimen 30 was used.

[0227] From the above, it was confirmed that the cured product 21a2 of the room temperature curable organopolysiloxane composition of Example 1 used in the example specimen 20 can exhibit higher heat resistance and heat insulation properties than the double folded plate 31a1 (with heat insulating material 31a2) used in the comparative example specimen 30.

[0228] <Evaluation of corrosion resistance> [Corrosion resistance test: salt spray cycle test] Corrosion resistance evaluation is based on the results of a salt spray cycle test. This salt spray cycle test is conducted in accordance with JIS standard K5600-7-9:2006 "General test methods for paints - Part 7: Long-term durability of coating films - Section 9: Cyclic corrosion test method - Salt spray / dry / wet". The test results are evaluated by visually observing the test surface of the test specimen.

[0229] [Test equipment] First, in this corrosion resistance test, a salt spray cycle test device (CYP-90: manufactured by Suga Test Instruments Co., Ltd.) is used as the test device. This salt spray cycle test device is used to conduct cycle tests that combine environmental conditions such as salt spray, dryness, and humidity, and conforms to the above-mentioned JIS standard K5600-7-9:2006 "5. Devices."

[0230] [Test conditions] The corrosion resistance test, i.e., salt spray cycle test, is conducted by continuously repeating a predetermined cycle a predetermined number of times. One cycle in this salt spray cycle test consists of three steps: salt spray, drying, and wetting, in that order, with the salt spray lasting 2 hours, followed by drying for 4 hours, and wetting for 2 hours, for a total of 8 hours.

[0231] In the corrosion resistance test of the cured product of this composition, the salt spray cycle test was conducted in two ways: Test 1, in which the above-mentioned cycle (8 hours / cycle) was repeated 90 times (total of 720 hours = 30 days), and Test 2, in which the above-mentioned cycle (8 hours / cycle) was repeated 105 times (total of 840 hours = 35 days). Note that this cycle is specifically in accordance with JIS standard K5600-7-9:2006, "Annex C (Regulations) Cycle A."

[0232] In this salt spray cycle test, the (1) salt spray operating conditions, (2) drying operating conditions, and (3) wetting operating conditions are as follows (1) to (3). These operating conditions (1) to (3) are in accordance with JIS standard K5600-7-9:2006 "Test specimen exposure method," "9. Operating conditions," and "Annex C (Regulations) Cycle A." (1) Salt spray operating conditions Spray liquid: Salt water (sodium chloride concentration 50g / L, pH 6.5) Temperature: 35°C in the test chamber, 35°C in the saltwater tank, 47°C in the air-saturated container Compressed air pressure: 100kPa (2) Drying operating conditions Temperature: 60℃ in the test chamber Relative humidity: 25%RH (3) Wetting operating conditions Temperature: 50℃ in the test chamber Relative humidity: 95%RH

[0233] [Test specimen] The test specimen was prepared by coating the composition on a substrate, specifically, under the following conditions (1) to (3). The test specimen was prepared based on JIS standard K5600-7-9:2006, "7. Test specimen." Figure 12, which will be described later, is a front view of the test specimen after the test. (1) Base material The substrate is a cold-rolled steel plate (JIS G3141) with a standard temper dull finish, specifically SPCC-SD. This substrate is a rectangular plate when viewed from the front, free of rust, scratches, dirt, discoloration, and other surface defects, and measures 150 mm long, 70 mm wide, and 0.8 mm thick. The four corners of the front surface of this substrate (the plane consisting of the vertical and horizontal directions in Figure 12) are chamfered using a so-called four-corner chamfering process. (2) Coating The coating film was formed by applying the composition using the blending ratio of Example 1 to the entire surface of the substrate (front, back, top, bottom, left, and right end surfaces). The composition was applied in three separate applications (S21) using the coating film formation process (S2) of the coating method shown in Figure 2, resulting in an average coating thickness of 700 μm (coating film thickness after drying). The composition was then dried (S22) as described above for Figure 2, but the coating film on the test specimen was dried in a location with free air circulation and avoiding direct sunlight. The front surface of the test specimen was used as the test surface, and the condition of this test surface after the corrosion resistance test was evaluated. (3) How to make the cut When making cuts on the test surface of a test specimen, the cuts shall be made in accordance with the following conditions: (a) The cut is a straight cut made through the coating on the test surface to the substrate. When making this cut, a single-edged cutting tool with a new cutting edge shall be used. (b) The cut is 0.1 to 1.0 mm wide on the substrate and has a cross section that penetrates from the substrate to the surface of the coating film. (c) Remove any debris that may have formed around the cut. (d) According to the method of making the cuts, two cuts are made in the lower half of the rectangular front surface (test surface) of the test specimen, within a range of at least 10 mm inward from the left and right end faces and bottom end face of the test specimen, intersecting in an X-shape when viewed from the front. (e) The notch shall be made in the test specimen immediately before the salt spray cycle test is conducted.

[0234] [Type of specimen to be evaluated] In this corrosion resistance test, two damaged specimens (hereinafter referred to as "damaged specimens") with cuts made according to the cut-making method described above and two undamaged specimens (hereinafter referred to as "undamaged specimens") with no such cuts made are prepared. Of these four specimens, one undamaged specimen and one damaged specimen are used for a 720-hour salt spray cycle test, and the other undamaged specimen and one damaged specimen are used for an 840-hour salt spray cycle test.

[0235] [Test Results] Figure 12 shows a front view of the test surface of the test specimen after the above-mentioned salt spray cycle test, particularly showing the area where blistering of the coating film occurred. Here, Figure 12(a) shows undamaged test specimen A7 after 720 hours of salt spray cycle test, Figure 12(b) shows undamaged test specimen A8 after 840 hours of salt spray cycle test, Figure 12(c) shows damaged test specimen B7 after 720 hours of salt spray cycle test, and Figure 12(d) shows damaged test specimen B8 after 840 hours of salt spray cycle test.

[0236] The dotted lines in Figures 12(c) and 12(d) indicate the outer edge of the area where the paint film bulges around the cut, and indicate that the paint film bulges appear within the area inside this dotted line.

[0237] Here, the test surfaces of the damaged specimens B7 and B8 have, in addition to the cuts described above, a contour area, a peripheral area, and an undamaged area. On the test surfaces of the damaged specimens B7 and B8, the cut is the area where the cut itself is located, the contour area is the coating area on the contour line of the cut, the peripheral area is the coating area outside the contour area and surrounding the contour, and the undamaged area is the coating area excluding the cut, the contour area, and the peripheral area.

[0238] [Evaluation criteria] In the evaluation of this corrosion resistance test, which is a salt spray cycle test, the coating films of the above-mentioned undamaged test specimens A7 and A8 and damaged test specimens B7 and B8 are visually observed and evaluated for the degree of change in the coating film, the amount of defects, the size of the defects, the grade of blistering, and the grade of rust.

[0239] [a. Evaluation of the degree of change in the coating film] [Evaluation criteria for the degree of change in coating film] The degree of uniform changes to the coating surface, such as changes in hue (e.g., yellowing) and chalking of the coating film, is indicated in accordance with JIS standard K5600-8-1:2014, and is shown in Table 5 below.

[0240] [Table 5]

[0241] [Evaluation results of the degree of change in the coating] Of the four test specimens, the evaluation results for the intact test specimens A7 and A8 based on Table 5 showed that no uniform changes were observed in the coating film on the test surface, and therefore the coating film change was "no change," and the grade of the degree of change was "0," so they were recorded as "no change: 0" as shown in (1) and (2) below. (1) Undamaged specimen A7: No change: 0 (2) Undamaged specimen A8: No change: 0

[0242] Here, for damaged specimens B7 and B8, dark brown rust formed by oxidation of the base material was exposed throughout the cut, a hue change resembling brownish-red rust appeared at the outline, and pale yellow, yellow, ochre, or yellowish-brown stains dripping from the base material within the cut appeared around the edge.

[0243] However, there was no rust that penetrated the paint film or any obvious rust that was present underneath the paint film in the outline, peripheral, or undamaged areas, and as for the degree of change in the paint film, although there were some changes in hue due to the cut scratches and rust in the outline and peripheral areas, there was no uniform change in hue in the paint film in the undamaged areas. Taking all of the above into consideration, the evaluation results for these damaged test specimens B7 and B8 based on Table 5 show that there was no uniform change in the paint film on the test surface, and therefore the paint film change was determined to be "no change," and the degree of change was graded as "0," and as a result, it was determined to be "no change: 0" as per (3) and (4) below. (3) Damaged specimen B7: No change: 0 (4) Damaged specimen B8: No change: 0

[0244] [b. Defect quantity evaluation criteria] The amount of defects (defects that impair the continuity of the coating film) scattered in a roughly similar pattern on the test surface of the test specimen shall be indicated in accordance with Table 6 below, with reference to JIS Standard K5600-8-1:2014. Note that if the defect is a "blister," this will be discussed separately below, and in this case, JIS Standard K5600-8-2:2014 shall be used as a reference.

[0245] [Table 6]

[0246] [c. Defect size evaluation criteria] When it is necessary to specifically indicate the average size of a defect, the following Table 7 should be used, with reference to JIS standard K5600-8-1:2014. In Table 7, when there are defects of various sizes on the test surface, the largest defect that quantitatively represents the test surface is used as the evaluation grade, and the defect is indicated by "Sn." S stands for size, and n indicates the grade.

[0247] [Table 7]

[0248] [Evaluation results of the amount and size of defects] Of all four test specimens, the intact test specimens A7 and A8 had no defects (which refers to all defects including blistering, rust, cracks, and peeling; the same applies below) scattered in roughly the same pattern on the test surface, i.e., no defects that impair the continuity of the paint film, and therefore were rated as "0" for the amount of defects and "S0" for the size of the defects.

[0249] However, since damaged specimens B7 and B8 have blistering and rust in some parts, as described below, the evaluation results for the amount of such defects will be explained in the evaluation of blistering and rust described below.

[0250] Therefore, the evaluation results based on Table 7 and Table 7 regarding the amount and size of defects for the four test specimens are summarized as follows (1) to (4). (1) Undamaged specimen A7: 0 defects (S0) (2) Undamaged specimen A8: 0 defects (S0) (3) Damaged specimen B7: See "Evaluation of blistering" and "Evaluation of rust" below. (4) Damaged specimen B8: See "Evaluation of blistering" and "Evaluation of rust" below.

[0251] [d. Evaluation of swelling] The degree of paint film blistering shall be evaluated and graded by comparing it with the grade samples shown in the reference plates in Figures 13 to 16. Here, the paint film blister grade refers to the amount (density) and size of the paint film blister, and shall refer to the method of indicating the grades related to the amount and size of defects based on Tables 6 and 7 above. The reference plates in Figures 13 to 16 for paint film blistering classify the size of the paint film blister into Grades 2, 3, 4, and 5, and the amount (density) into Grades 2, 3, 4, and 5.

[0252] [Evaluation criteria for swelling grades] The grade of blistering of the coating film is evaluated based on the amount (amount per unit area) and size, specifically with reference to JIS standard K5600-8-2:2008. The reference plates shown in Figures 13 to 16 are monochrome images of "Figures 1 to 4" of JIS standard K5600-8-2:2008 (based on JIS standard K5600-8-2:2008 "Appendix A (Regulations) Calibration Images").

[0253] The reference plates in Figures 13 to 16 are the evaluation standards for assessing the grade of blistering of the paint film, and show the state of the blistering of the paint film, with Figure 13 indicating grade 2, Figure 14 indicating grade 3, Figure 15 indicating grade 4, and Figure 16 indicating grade 5, respectively.

[0254] Furthermore, the reference plates in Figures 13 to 16 each show four levels of reference plates for the level of blistering (density) of the paint film, with (a) in each figure showing level 2, (b) in each figure showing level 3, (c) in each figure showing level 4, and (d) in each figure showing level 5. The level (density) and size of the blistering of the paint film are both set to increase as the level increases from level 2 to level 5.

[0255] [Bulging grade evaluation results] When the coating films of the four test specimens A7, A8, B7, and B8 were evaluated based on the reference drawings in Figures 13 to 16, of all four test specimens A7, A8, B7, and B8, the intact test specimens A7 and A8 showed no defects, including swelling of the coating film on the test surface, as explained above in "Evaluation results of the amount of defects" (1) and (2) and "Evaluation results of the size of defects" (1) and (2).

[0256] In contrast, for the damaged specimens B7 and B8, there was a bulge in the paint film in the area adjacent to the cut, and when the amount (density) and size of this bulge were evaluated based on the reference drawings in Figures 13 to 16, the amount (density) of the bulge for both specimens B7 and B8 was considered to be graded as "5" and the size as "S5". In summary, the evaluation results for the bulge in the paint film of the four specimens A7, A8, B7, and B8 are as shown in the following (1) to (4). (1) Undamaged specimen A7: 0 defects (S0) (2) Undamaged specimen A8: 0 defects (S0) (3) Damaged specimen B7: Blister: 5 (S5) (4) Damaged specimen B8: Blister: 5 (S5)

[0257] The blistering of the coating of these damaged specimens B7 and B8 only occurred in the area around the cut on the damaged specimens B7 and B8, up to a distance of approximately 10 mm from the cut, and it is thought that the area where the blistering occurred (the area within the dotted line in the figure) was limited. Furthermore, since the number of test cycles for damaged specimen B7 was smaller than that for damaged specimen B8, the impact of corrosion by saltwater was smaller, and therefore the area where the blistering occurred is thought to be smaller than that for damaged specimen B8.

[0258] [e. Rust evaluation] The degree of rust on the paint film shall be evaluated and graded by comparing it with the grade samples in the standard diagram in Figure 17. Here, the grade of rust on the paint film refers to the grade based on the degree of rust formation on the paint film (rust that has penetrated the paint film and rust that is clearly visible from below the paint film). The standard diagram in Figure 17 for rust on the paint film illustrates the condition of the test surface of test specimens that have deteriorated to various grades through a combination of rust that has penetrated the paint film and rust that is clearly visible from below the paint film.

[0259] [Rust grade evaluation criteria] The rust grade of the paint film is evaluated based on the Ri grading of rust on the paint film. Specifically, JIS standard K5600-8-3:2008 is used as a reference. The reference plate in Figure 17 is a monochrome image of JIS standard K5600-8-3:2008 "Figures 1 to 5" (based on JIS standard K5600-8-3:2008 "Appendix A (Regulations) Calibration Images").

[0260] The reference plate in Figure 17 is an evaluation standard for assessing the rust grade of a paint film, and shows the state of rust on the paint film with respect to the Ri grade of rust on the paint film, with Figure 17(a) showing grade Ri1, Figure 17(b) showing grade Ri2, Figure 17(c) showing grade Ri3, Figure 17(d) showing grade Ri4, and Figure 17(e) showing grade Ri5. The Ri grade of rust on a paint film is set so that the area of ​​rust increases as the grade increases from 0 to 5, and grade Ri0 is a grade that indicates the state of rust on a paint film where the area of ​​rust (this refers to the total area of ​​rust that has penetrated the paint film and rust that is clearly visible beneath the paint film; the same applies below) is 0% (no rust has appeared).

[0261] Table 8 below shows the relationship between the rust area and the rust grade shown on the standard plate in Figure 17, and can be used as a reference when evaluating the rust grade based on the standard plate in Figure 17.

[0262] [Table 8]

[0263] [Rust grade evaluation results] [About the intact specimen] Of the four test specimens A7, A8, B7, and B8, the undamaged test specimens A7 and A8 were evaluated for rust on the coating film based on Figure 17 and Table 8, and as shown in the above-mentioned "Evaluation results of the amount and size of defects" (1) and (2), no defects including rust on the coating film were found on the test surface.

[0264] [About the damaged test specimen] In contrast, for the remaining damaged specimens B7 and B8, rust and color changes caused by rust are present in the cuts, outlines, peripheral areas, and undamaged areas, so it is necessary to take these into consideration when evaluating the grade.

[0265] [About cuts] First, dark brown rust appeared throughout the cuts on the test surfaces of damaged specimens B7 and B8. This rust in the cuts was rust on the substrate surface that was exposed at the cut, and did not extend extensively to the outline or surrounding areas. Because the rust in the cuts was present throughout the entire cut, the Ri grade of this cut would be "Ri5" in Figure 17(e) based on the reference plate in Figure 17 and Table 8. Since the width of the cut was 0.5 mm or less, this corresponds to a rust spot size of 0.5 mm or less, and therefore the grade of the size of this rust spot would be considered to be "S3" based on Table 7.

[0266] [About the outline] Furthermore, the outlines of the test surfaces of damaged specimens B7 and B8 only had extremely small amounts of brown rust (including colored areas that looked like rust) that appeared locally (for example, in one or a few places). In light of this, based on the reference plate in Figure 17 and Table 8, the Ri grade of the rust on these outlines would be considered to be "Ri1" in Figure 17(a), and the size grade of these rust spots would be considered to be "S1" based on Table 7.

[0267] [Regarding the peripheral and non-scar areas] Additionally, there is no rust on the periphery or undamaged areas of the test surface of damaged specimens B7 and B8, but there are pale yellow, yellow, ochre, or yellowish-brown rust stains dripping from the periphery due to rust on the base material within the cut. Therefore, based on the reference plate in Figure 17 and Table 8, the Ri grade of the rust on the periphery and undamaged areas is considered to be "Ri0," and the grade of the size of these rust spots is considered to be "S0" based on Table 7.

[0268] [Summary of evaluation results] Therefore, the rust grade evaluation results for the coatings on the test surfaces of the four test specimens A7, A8, B7, and B8, based on Tables 7 and 8 above and the reference plate in Figure 17, are summarized as shown in the following (1) to (4). (1) Undamaged specimen A7...Rust: Ri0(S0) (2) Undamaged specimen A8...Rust: Ri0(S0) (3) Damaged specimen B7 (a) Cutting wound...Rust: Ri5 (S3) (b) Outline: Rust: Ri1(S1) (c) Periphery: Rust: Ri0(S0) (d) Undamaged area: Rust: Ri0(S0) (4) Damaged specimen B8 (a) Cutting wound...Rust: Ri5 (S3) (b) Outline: Rust: Ri1(S1) (c) Periphery: Rust: Ri0(S0) (d) Undamaged area: Rust: Ri0(S0)

[0269] [f. Evaluation of cracks and peeling] [Crack and peeling evaluation criteria and evaluation results] As a result of this corrosion resistance test, the test surfaces of all test specimens A7, A8, B7, and B8 were evaluated for cracking (evaluation criteria in accordance with JIS standard K5600-8-4:1999) and peeling (evaluation criteria in accordance with JIS standard K5600-8-5:1999), and no cracking or peeling was observed on any of the test specimens.

[0270] As explained above, according to the evaluation results of corrosion resistance, for all of the test specimens A7, A8, B7, and B8, regardless of whether or not they had cuts, the coating film on the test surface, except for the cuts and their outlines, showed no rust (this refers to rust that penetrates the coating film and rust that is clearly present beneath the coating film; the same applies hereinafter), cracks, or peeling, and it can be said that the cured product of this composition has excellent corrosion resistance.

[0271] Furthermore, even when cuts were made as in the damaged specimens B7 and B8, the cured product of this composition showed swelling limited to an extremely limited area around the cut, as shown in Figure 12, and it is believed that the area in which swelling appears can be limited to a narrower area than with other types of coating films.

[0272] According to the present invention explained using the above embodiments and examples, the present cured product formed by curing the present composition has an elastically stretchable rubber structure in which the siloxane bonds formed by crosslinking the base polymer of component (A) into a three-dimensional network structure through a crosslinking reaction, and therefore can exhibit waterproofing, conformability, and scratch resistance to substrates.

[0273] Furthermore, the present composition and the present cured product can exhibit excellent adhesion to substrates via the adhesion improver, and also have excellent weather resistance as described above. Therefore, it is believed that these properties combined together make it possible for the present cured product, when used as a coating film on a substrate, to prevent cracks from appearing in the coating film over a long period of time and to prevent the substrate from being exposed to the atmosphere through such cracks over a long period of time, thereby making it less likely for rust to form on the surface of the substrate.

[0274] Furthermore, because the base polymer of component (A) of this composition is dimethylpolysiloxane, and this becomes the cured product through crosslinking and curing, the silicone oil component impregnates the surface of the substrate, making it easier to prevent oxidation of the substrate surface. In addition, the gas permeability of the cured product allows moisture and other water remaining between the substrate and the cured coating film to pass through the cured product and be released into the atmosphere, thereby preventing rusting of the substrate beneath the coating film and suppressing the growth of blisters in the coating film.

[0275] Therefore, the present composition and the present cured product exhibit excellent functions as a non-flammable material, as well as excellent functions in weather resistance, heat resistance, heat insulation, and corrosion resistance. In addition, they also have excellent waterproofing, conformability, adhesion, and scratch resistance to substrates, and they also have excellent gas permeability, allowing moisture and other water remaining on the surface of the substrate to pass through as water vapor. [Explanation of symbols]

[0276] 1. Cured product of room temperature curable organopolysiloxane composition (silicone) 2 Base material 20 Example device (structure) 21a Example test specimen (component) 21a2 Cured product of room temperature curable organopolysiloxane composition

Claims

1. A silicone resin coating film formed from a cured product of a room-temperature-curable organopolysiloxane composition applied to an object to be coated, comprising: The room-temperature-curable organopolysiloxane composition contains (A) an organopolysiloxane as a base polymer having a viscosity of 100 to 500,000 mPa·s at 23°C, and (B) an inorganic substance as an inorganic filler, The (A) base polymer has a siloxane bond, which is an inorganic component, and an organic group, which is an organic component, and the content of the siloxane bond is 59% by mass or more and the content of the organic group is 41% by mass or less, relative to 100% by mass of the (A) base polymer; the (B) inorganic filler is contained in an amount of 100 parts by mass or more and 150 parts by mass or less relative to 100 parts by mass of the (A) base polymer, The room temperature curable organopolysiloxane composition is applied smoothly to the object to be coated in an amount of 600±60 g / m ２ More than 800±80g / m ２ It is painted and applied as follows: The cured product of the room-temperature-curable organopolysiloxane composition is a silicone resin coating film characterized by having inorganic siloxane bonds with an elastically stretchable rubber structure formed by crosslinking the organopolysiloxane base polymer (A) into a three-dimensional network structure.

2. The surface of the cured product is exposed to 50 kW / m2 of a radiant electric heater, as measured in accordance with "4.9.2 Heat Generation Test" in the "Fire Resistance Testing and Evaluation Procedure Manual" (revised April 1, 2023) of the Japan Testing Center for Construction Materials. ２ In a heat generation test in which radiant heat of 8 MJ / m is irradiated, the total heat generation amount for 20 minutes after the start of heating is 8 MJ / m ２ It is the following: In the heat generation test, there are no cracks or holes penetrating to the back surface that are harmful to fire prevention within 20 minutes after heating begins. In the heat generation test, the heat generation rate within 20 minutes after the start of heating is 200 kW / m for 10 seconds or more. ２ 2. The silicone resin coating film according to claim 1, wherein the thickness of the coating film is not more than 100 μm.

3. A structural component used on the exterior and / or interior of a structure as an object to be coated, characterized in that the structural component is provided with a silicone-based resin coating film according to claim 1 or 2 that is formed as a coating on the surface of the structural component.

4. A structure comprising a component material that will be a part or member on the exterior and / or interior of the structure as an object to be coated, and the silicone-based resin coating film according to claim 1 or 2 that is formed and painted on the surface of the component material.

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