JP7624846B2 - Coating structure and film thickness measurement method - Google Patents

Description

The present invention relates to a novel coating structure and a method for measuring film thickness.

In order to protect the steel frame materials, steel materials, and other substrates that make up buildings from fire, various thermally foamable coating materials have been proposed that foam when the temperature rises during a fire or other event, forming a carbonized insulation layer. Known examples of such thermally foamable coating materials include synthetic resins mixed with foaming agents, carbonizing agents, and flame retardants. The heat-resistant protective performance of thermally foamable coating materials is often determined by the coating thickness, and in order to obtain the desired heat-resistant protective performance, it is important to form a coating of a specified thickness uniformly on the substrate. Generally, the thickness of the thermally foamable coating layer formed on the substrate of steel frame materials, steel materials, and other substrates is measured using an electromagnetic or eddy-current coating thickness gauge (for example, Patent Document 1 and Patent Document 2).

Meanwhile, in recent years, in order to further improve the heat resistance and protective performance of buildings, the formation of a thermally foamable coating layer on various substrates, such as concrete, mortar, wood, synthetic resins, and fibrous materials in addition to steel frame materials and steel materials, has been considered.

JP 2003-088799 A JP 2018-159065 A

However, depending on the type of substrate, there are cases where the film thickness cannot be measured or cannot be measured accurately. The present invention has been made in consideration of such problems, and aims to provide a coating structure that allows the film thickness of a thermally foamable coating material to be measured regardless of the type of substrate.

To solve these problems, the inventors discovered that in a structure in which a thermally foamable coating layer is laminated onto a substrate, by fixing a specific auxiliary member to the substrate surface, it is possible to measure the film thickness of the thermally foamable coating material regardless of the type of substrate, leading to the completion of the present invention.

That is, the present invention has the following features.
1. A covering structure in which a thermally foamable covering layer is laminated on a substrate, the substrate being a non-metallic material, the non-metallic material being a fiber-based insulating material or a foamed plastic-based insulating material, an auxiliary member being fixed to the surface of the substrate using a fastener , the auxiliary member having a metal material on at least its upper surface,
The fastener is inserted into the base to be fixed thereto, and a layer of thermally foamable coating material is laminated to cover the auxiliary member on the base, thereby forming a covered structure.
2. The covering structure according to 1., wherein the head has an area of ¹ cm2 or more and a thickness of 0.1 μm or more and 5 mm or less.
3. The covering structure according to 1., wherein the fastener has a length of 5 to 100 mm and is shorter than the thickness of the base.
4. A method for measuring the thickness of a thermally foamable coating layer in a coated structure according to any one of 1. to 3. , comprising measuring a distance from a surface of the thermally foamable coating layer to a head of the auxiliary member by an electromagnetic or eddy-current type thickness meter.
5. A method for forming a covering structure in which a thermally foamable covering material layer is laminated on a base, comprising a step of fixing an auxiliary member to a surface of the base by piercing a fastener , and then coating the thermally foamable covering material, the base being a non-metallic material, the non-metallic material being a fiber-based insulating material or a foamed plastic-based insulating material, the auxiliary member having a metallic material at least on its upper surface,
A method for forming a covered structure, comprising applying a thermally foamable covering material to the base so as to cover the auxiliary member.

The structure of the present invention can stably measure the film thickness of the thermally foamable coating material regardless of the type of substrate. This makes it possible to stably obtain the desired heat-resistant protection performance when temperatures rise due to fires, etc.

An example of the covering structure of the present invention is shown. An example of the covering structure of the present invention is shown. 1 shows an example (enlarged view) of a coated structure of the present invention. An example of the covering structure of the present invention is shown. 1 shows an example (enlarged view) of a coated structure of the present invention. An example of the film thickness measuring method of the present invention will be described. An example of the covering structure of the present invention is shown.

1. Base 2. Thermally foamable coating material layer 3. Auxiliary member 31. Adhesive 32. Fastener 4. Base material 41. H-shaped steel frame 5. Film thickness gauge

The present invention will be described in detail below based on its embodiments.

<Covering structure>
Fig. 1(I) is a cross-sectional view showing an example of a coated structure of the present invention. In Fig. 1(I), a thermally foamable coating layer 2 is laminated on a base 1. An auxiliary member 3 is fixed to the surface of the base 1, and the thermally foamable coating layer 2 is laminated so as to cover the auxiliary member 3.

Figure 1 (II) is a cross-sectional view showing another example of the covering structure of the present invention. As shown in Figure 1 (II), the base 1 may be a laminate of a base material 4 such as a steel frame material or steel material that constitutes a building. Specifically, in Figure 2, the base 1 is covered on an H-shaped steel frame 41, an auxiliary member 3 is fixed to the base 1, and a thermally foamable covering material layer 2 is laminated to cover the auxiliary member 3.

(Base)
The base 1 of the present invention is characterized by being a non-metallic material. Examples of non-metallic materials include wood materials; inorganic materials such as lightweight mortar, lightweight concrete, calcium silicate board, ALC board, siding board, gypsum board, slate board, concrete, and mortar; and insulation materials such as fiber insulation materials such as glass wool, rock wool, cellulose fiber, and insulation board, and foamed plastic insulation materials such as polyethylene foam, polystyrene foam, and polyurethane foam. In particular, the present invention can stably measure the thickness of the thermal foaming coating layer 2 formed on the surface of flexible materials such as fiber insulation materials and foamed plastic insulation materials, so that the desired heat-resistant protection performance can be stably obtained.

The thickness of the above-mentioned base 1 is not particularly limited, but is preferably 5 to 500 mm (more preferably 10 to 300 mm). In the present invention, even if the base 1 has a thickness, the thickness of the thermally foamed coating material layer formed on its surface can be stably measured, so that the desired heat-resistant protective performance can be stably obtained. In the present invention, "α to β" is synonymous with "α or more and β or less."

(Thermal foamable covering layer)
The thermally foamable coating layer 2 of the present invention is formed from a thermally foamable coating material that foams when the ambient temperature rises due to a fire or the like and the coating temperature reaches a predetermined foaming temperature (preferably 150° C. or higher, more preferably 180° C. or higher, and even more preferably 200 to 400° C.) and forms a carbonized heat insulating layer in that temperature range. As such a thermally foamable coating material, one containing a resin component, a flame retardant, a foaming agent, a carbonizing agent, and a filler as constituent components is preferable.

The resin component may be a water-dispersible type, a water-soluble type, an NAD type, a solvent-soluble type, a solventless type, or the like, and may be one-liquid type, two-liquid type, or the like, without any particular limitation. Specific examples include organic synthetic resins such as vinyl acetate resin, vinyl acetate/vinyl ester versatic acid copolymer resin, vinyl acetate/ethylene copolymer resin, vinyl acetate/vinyl ester versatic acid/acrylic copolymer resin, vinyl acetate/acrylic copolymer resin, acrylic resin, acrylic/styrene resin copolymer resin, epoxy resin, urethane resin, polyester resin, polybutadiene resin, alkyd resin, and vinyl chloride resin. These may be used alone or in combination of two or more.

The flame retardant of the present invention generally exerts at least one of the following effects in the event of a fire: dehydrating and cooling effect, non-flammable gas generation effect, carbonization promotion effect, etc., and has the effect of suppressing the combustion of the resin component. The flame retardant used in the present invention is not particularly limited as long as it has such an effect, and known flame retardants can be used. For example, organic phosphorus compounds such as tricresyl phosphate, diphenyl cresyl phosphate, diphenyl octyl phosphate, tri(β-chloroethyl) phosphate, tributyl phosphate, tri(dichloropropyl) phosphate, triphenyl phosphate, tri(dibromopropyl) phosphate, chlorophosphonate, bromophosphonate, diethyl-N,N-bis(2-hydroxyethyl)aminomethyl phosphate, and di(polyoxyethylene)hydroxymethyl phosphonate; chlorine compounds such as chlorinated polyphenyl, chlorinated polyethylene, diphenyl chloride, triphenyl chloride, pentachlorinated fatty acid esters, perchloropentacyclodecane, chlorinated naphthalene, and tetrachlorophthalic anhydride; antimony compounds such as antimony trioxide and antimony pentachloride; phosphorus compounds such as phosphorus trichloride, phosphorus pentachloride, ammonium phosphate, and ammonium polyphosphate; and boron compounds such as zinc borate and sodium borate. These may be used alone or in combination of two or more. In addition, uncoated products can be used, but coated products can also be used.

The mixing ratio of the flame retardant is preferably 50 to 1000 parts by weight, more preferably 100 to 800 parts by weight, and more preferably 200 to 600 parts by weight, per 100 parts by weight (solid content) of the resin component. In the present invention, by including a relatively high ratio of flame retardant in this way, good performance in terms of heat resistance protection can be obtained.

The foaming agent of the present invention generally has the effect of generating a non-flammable gas in the event of a fire, foaming the resin component and the carbonizing agent that are being carbonized, and forming a carbonized insulation layer having air holes. The foaming agent is not particularly limited as long as it has such an effect, and any known foaming agent can be used. Examples include melamine and its derivatives, dicyandiamide and its derivatives, azodicarbonamide, urea, and thiourea. These can be used alone or in combination of two or more. The mixing ratio of the foaming agent is preferably 5 to 500 parts by weight, more preferably 30 to 200 parts by weight, per 100 parts by weight (solid content) of the resin component. By being in such a range, excellent foaming properties can be exhibited and good performance in terms of heat resistance protection can be obtained.

The carbonizing agent of the present invention generally has the effect of forming a thick carbonized insulation layer with excellent heat insulation properties by dehydrating and carbonizing itself as the resin component is carbonized by fire. The carbonizing agent used in the present invention is not particularly limited as long as it has such an effect, and known carbonizing agents can be used. Examples include polyhydric alcohols such as pentaerythritol, dipentaerythritol, and trimethylolpropane; starch, casein, etc. These can be used alone or in combination of two or more. The mixing ratio of the carbonizing agent is preferably 5 to 600 parts by weight, more preferably 10 to 400 parts by weight, per 100 parts by weight (solid content) of the resin component. By being in such a range, it is possible to exert a dehydration cooling effect and a carbonized insulation layer forming effect, and to obtain good performance in terms of heat resistance protection.

The filler of the present invention generally has the effect of maintaining the strength of the carbonized insulation layer. In the present invention, examples of the filler include titanium dioxide, calcium carbonate, and inorganic fibers. These can be used alone or in combination of two or more. The mixing ratio of the filler is preferably 5 to 600 parts by weight, and more preferably 10 to 400 parts by weight, per 100 parts by weight (solid content) of the resin component.

The thermally foamable coating material of the present invention can also contain various additives in addition to the above. Examples of such ingredients include pigments, fibers, thickeners, film-forming assistants, leveling agents, wetting agents, plasticizers, antifreeze agents, pH adjusters, preservatives, antifungal agents, anti-algae agents, antibacterial agents, dispersants, defoamers, adsorbents, crosslinking agents, UV absorbers, antioxidants, catalysts, etc. Expandable substances such as expandable graphite and unexpanded vermiculite can also be added.

The thickness of the thermally foamable covering layer 2 of the present invention is set according to the desired heat-resistant protection performance, but is preferably about 0.2 to 10 mm, and more preferably about 0.5 to 6 mm. By laminating such thermally foamable covering layers 2, excellent heat-resistant protection can be achieved when exposed to high temperatures such as during a fire.

(Auxiliary member)
The auxiliary member 3 of the present invention is fixed to the base 1 and is an auxiliary member for measuring the film thickness of the thermally foamable coating material layer 2 laminated on the base 1.

The auxiliary member 3 is characterized by having a metal material at least on its upper surface (the surface opposite to the base surface). For example, a metal material or at least one material selected from resin, wood, fiber material, paper, etc., on which a metal material is laminated, can be used as the auxiliary member 3. Examples of the metal material include magnetic metals and non-magnetic metals, such as iron, steel, stainless steel, aluminum, copper, brass, etc. These materials can be used alone or in combination of two or more. In addition, the surfaces of these metal materials may be subjected to some kind of surface treatment as long as it does not impair the effects of the present invention. By using such an auxiliary member 3, the thickness of the thermally foamable coating material layer 2 laminated on the base 1 can be easily measured by an electromagnetic or eddy current type thickness gauge.

The auxiliary member 3 is characterized in that its area is preferably 1 ^cm2 or more (more preferably 1 ^cm2 or more and 25 ^cm2 or less, and even more preferably 1 ^cm2 or more and 10 ^cm2 or less) and its thickness is preferably 0.1 μm or more and 5 mm or less (more preferably 0.5 μm or more and 3 mm or less). In such a case, the film thickness can be stably measured. Furthermore, when the area and thickness satisfy the above ranges, the transfer of heat to the base 1 can be suppressed, and sufficient heat resistance protection can be ensured.

The upper surface of the auxiliary member 3 is preferably flat, and may be, for example, a film, sheet, or plate. The planar shape is not particularly limited, but examples include a triangle, a square (rectangle, trapezoid, diamond, etc.), a polygon, a circle, an ellipse, etc., and the corners may be rounded.

The method for fixing the auxiliary member 3 of the present invention may be appropriately determined depending on the base 1, and for example, an adhesive, a fastener, or the like may be used.
3 is an enlarged view of the covering structure of the present invention, showing an example of the auxiliary member 3 fixed with adhesive 31. When fixing with adhesive 31, for example, adhesive 31 may be applied to the underside (base surface side) of the base 1 and/or auxiliary member 3, and the auxiliary member may be attached to the base surface. Alternatively, an auxiliary member 3 with adhesive 31 pre-laminated on one side (for example, a metal tape) may be used.

Figures 4 (I) and (II) are cross-sectional views showing an example of the covering structure of the present invention. In Figure 4, the auxiliary member 3 is fixed to the base 1 using a fastener 32, and the thermally foamable covering material layer 2 is laminated so as to cover the auxiliary member 3. Figure 5 is an enlarged view of the covering structure of the present invention, showing an example of the auxiliary member 3 fixed with a fastener 32. In the case of fixing with the fastener 32, for example, a method of fixing by fitting the fastener 32 into a hole provided in the auxiliary member 3 (Figure 5 (I)), or a method of fixing with the auxiliary member 3 in which the auxiliary member 3 and the fastener 32 are previously joined and integrated (Figure 5 (II)), etc. can be mentioned. In addition, two or more fasteners 32 may be used (Figure 5 (III)). Furthermore, in the present invention, the adhesive 31 and the fastener 32 can be used in combination.

The fastener 32 is not particularly limited as long as it can be fixed to the base 1, and multiple fasteners 32 can be used. The fastener 32 is preferably fixed by piercing the base 1, and its shape is preferably sharp. The fastener 32 may also have a screw portion. The length (H32) of the fastener 32 is preferably 5 to 100 mm (more preferably 8 to 50 mm), and the thickness of the fastener 32 is preferably 0.5 to 5 mm (more preferably 1 to 4 mm). In such a case, the auxiliary member 3 can be sufficiently fixed to the base 1. In particular, the auxiliary member 3 can be stably fixed even if the base 1 is made of a flexible material or an existing material that has deteriorated over time. As a result, when the coated structure of the present invention is exposed to high temperatures such as during a fire, the thermally foamable coating material layer can stably foam and form a carbonized insulation layer, and the formed carbonized insulation layer can be prevented from falling off the base 1.

Furthermore, it is preferable that the length (H32) of the fastener 32 is shorter than the thickness of the base 1. Specifically, it is preferable that the length (H32) of the needle portion 32 is shorter than the thickness (H1) of the base 1 by 5 mm or more (more preferably 8 mm or more). In such a case, heat is less likely to be transferred to the base 1, and the desired heat resistance protection can be sufficiently obtained.

The material of the fastener 32 is not particularly limited, and examples include metal materials, resins, wood, etc. In the present invention, non-flammable materials are preferred, and metal materials are particularly preferred.

The configuration of the coating structure of the present invention is described in detail below.

(Method of forming a covering structure)
The covered structure of the present invention can be obtained, for example, by fixing an auxiliary member 3 to a base 1 and then applying a thermally foamable covering material to the base 1 to form a thermally foamable covering material layer 2 .

The auxiliary member 3 is preferably fixed to the surface of the substrate 1 using adhesive 31 and/or fasteners 32 so that the auxiliary member 3 fits along the surface. This allows for stable fixation to the substrate 1, and allows for stable measurement of the thickness of the thermally foamable coating layer. It is also preferable to use multiple auxiliary members 3 depending on the shape and size of the substrate 1. This allows for the formation of a thermally foamable coating layer of uniform thickness.

The thermally foamable coating layer 2 is formed by applying the thermally foamable coating material to the base 1 with the auxiliary member 3 fixed thereto. When applying the thermally foamable coating material, spray coating using a spray gun, airless spray gun, or pressure feeder, trowel coating, brush coating, roller coating, or the like can be used. When applying the coating, the viscosity can be adjusted appropriately using a diluting solvent.

The thickness of the thermally foamable coating layer 2 can be set appropriately depending on the heat-resistant protective performance, application area, etc., but is usually about 0.1 to 20 mm, preferably about 0.3 to 10 mm. When painting the thermally foamable coating material, multiple coats can be applied to achieve a desired coating thickness.

When the covering structure of the present invention is exposed to high temperatures such as during a fire, the anchor effect of the auxiliary member 3 allows the thermally foamable covering layer 2 to foam stably and form a carbonized insulation layer, while preventing the formed carbonized insulation layer from falling off the base 1. In addition, the base 1 and the thermally foamable covering layer 2, excluding the fixing portion of the auxiliary member 3, have excellent adhesion, and the desired heat resistance protection can be sufficiently obtained.

<Film thickness measurement method>
In the coated structure of the present invention, the film thickness of the thermally foamable coating layer 2 laminated on the base 1 can be measured using an electromagnetic or eddy-current film thickness meter, as shown in Fig. 6. The auxiliary member 3 is fixed to the base 1, and the thermally foamable coating layer 2 is laminated so as to cover the auxiliary member 3. By measuring the distance X from the surface of the thermally foamable coating layer 2 to the auxiliary member 3, the film thickness of the thermally foamable coating layer 2 can be measured.

The following examples will clarify the features of the present invention.

(Thermal foaming coating material)
250 parts by weight of acrylic resin solution (solid content 40% by weight) and 90 parts by weight of dilution solvent were added, and then mixed and stirred with a dissolver. Next, 100 parts by weight of melamine, 100 parts by weight of dipentaerythritol, 400 parts by weight of ammonium polyphosphate, and 120 parts by weight of titanium oxide were added and stirred until homogenized to prepare a thermally foamable coating material.

(Test Example 1)
As shown in FIG. 2, an aluminum tape [1.5 cm x 1.5 cm x 80 μm thick (aluminum layer 50 μm, adhesive layer 30 μm)] was attached and fixed as an auxiliary member to the base of an H-shaped steel frame 41 (H400 x 200 x 8 x 13 mm, length 1200 mm) coated with a 25 mm thick fiber-based insulation material. At this time, the auxiliary members were fixed at intervals of 300 mm in the length direction of the H-shaped steel frame 41. Next, the thermally foamable coating material was applied with a roller to form a thermally foamable coating layer, which was used as a test specimen. At this time, the thermally foamable coating layer was formed to a uniform thickness (3.7 mm) at the part of the test specimen where the auxiliary member was fixed, while measuring the thickness using an eddy current type thickness meter.
The prepared test specimens were subjected to a 3-hour heating test in accordance with the standard heating curve of ISO 834. As a result, the carbonized heat insulating layer was formed almost uniformly without falling off, and showed good heat resistance performance.

(Test Example 2)
As shown in Figure 7, an auxiliary member [auxiliary member shown in Figure 5 (II) (iron, rectangular plate: 1.5 cm x 1.5 cm x thickness 0.6 mm, area 2.25 cm2, fastener (iron, length 15 mm, thickness 1.2 mm)] with a fastener previously joined was pierced and fixed to the base, which was a H-shaped steel frame 41 ( ^H400 x 200 x 8 x 13 mm, length 1200 mm) covered on the surface with a 25 mm-thick fiber-based insulation material. At this time, the auxiliary members were fixed at intervals of 300 mm in the longitudinal direction of the H-shaped steel frame 41. Next, the thermally foamable coating material was applied with a roller to form a thermally foamable coating material layer, and the test specimen was prepared. At this time, the thermally foamable coating material layer was formed to a uniform thickness (3.7 mm) at the part of the test specimen where the auxiliary member was fixed, while measuring the film thickness with an electromagnetic film thickness meter.
The prepared test specimens were subjected to a 3-hour heating test in accordance with the standard heating curve of ISO 834. As a result, the carbonized heat insulating layer was formed almost uniformly without falling off, and showed good heat resistance performance.

Claims (4)

A covering structure in which a thermally foamable covering material layer is laminated on a substrate, the substrate being a non-metallic material, the non-metallic material being a fiber-based insulating material or a foamed plastic-based insulating material, an auxiliary member being fixed to a surface of the substrate using a fastener , the auxiliary member having a metal material on at least its upper surface,
The fastener is fixed by piercing the base, and a covered structure is characterized in that a thermally foamable covering material layer is laminated to cover the auxiliary member on the base. 2. The covering structure according to claim 1, wherein the auxiliary member has an area of ¹ cm2 or more and a thickness of 0.1 μm or more and 5 mm or less. 2. The covering structure according to claim 1, wherein the fastener has a length of 5 to 100 mm, which is shorter than the thickness of the base. 4. A method for measuring a thickness of a thermally foamable coating layer in a coated structure according to claim 1, comprising measuring a distance from a surface of the thermally foamable coating layer to the auxiliary member by an electromagnetic or eddy-current type thickness meter.

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