JP7484171B2 - Non-flammable sheet - Google Patents

Description

The present invention relates to a non-flammable sheet.

Some non-combustible sheets, which are non-combustible or flame-retardant sheets, contain inorganic materials in the base layer, which is the base material layer. Technology relating to these sheets is described, for example, in Patent Document 1.

JP 2018-48229 A

In some noncombustible sheets containing inorganic materials in the original layer, the inorganic materials fall off the surface of the original layer when printing, etc., is performed on the surface of the original layer, that is, the so-called powder fall. If the inorganic materials fall off the sheet after printing, etc., they may contaminate, for example, the inside of a printing system, specifically, the inside of a printing device.
In addition, some non-combustible sheets containing inorganic materials in the base layer have poor adhesion between the base layer and the ink used to form the printed layer when a printed layer is formed directly on the surface of the base layer, and peeling occurs inside the printed layer or between the base layer and the printed layer. Such non-combustible sheets are unsuitable for use as building materials, for example, because the printed layer may peel off during use.

Therefore, the present invention aims to provide a non-combustible sheet that can prevent the powder falling off of the inorganic material contained in the original fabric layer and can improve the interlayer strength between the original fabric layer and the printed layer.

In order to achieve the above object, a non-combustible sheet according to one aspect of the present invention comprises an original fabric layer, a first anchor layer formed on a first surface of the original fabric layer, and a second anchor layer formed on a second surface of the original fabric layer opposite to the first surface, the original fabric layer containing a thermoplastic resin and an inorganic material, and the first anchor layer contains a urethane-based resin containing vinyl chloride and acetate, or an acrylic-based resin containing vinyl chloride and acetate, in a range of 15% by mass to 100% by mass relative to the total mass of the first anchor layer.

The present invention provides a non-combustible sheet that can prevent the inorganic material contained in the base layer from falling off and can improve the interlayer strength between the base layer and the printed layer.

1 is a cross-sectional view showing a configuration of a noncombustible sheet and a noncombustible material according to a first embodiment of the present invention. FIG. 4 is a cross-sectional view showing the configuration of a noncombustible sheet and a noncombustible material according to a modified example of the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing the configuration of a noncombustible sheet and a noncombustible material according to a second embodiment of the present invention.

Next, an embodiment of the present invention will be described with reference to the drawings.
Here, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc. differ from the actual ones. Furthermore, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention, and the technical idea of the present invention is not limited to the materials, shapes, structures, etc. of the components described below. The technical idea of the present invention can be modified in various ways within the technical scope defined by the claims.

First Embodiment
[Configuration of fireproof sheet]
1, the noncombustible sheet 10 of the first embodiment includes, from the rearmost side to the frontmost side, a primer layer 6, a back anchor layer 5, a raw fabric layer 1, a front anchor layer 2, a picture pattern layer 3, and a top coat layer 4. The noncombustible material 12 of the first embodiment includes the noncombustible sheet 10 of the first embodiment and a substrate 11.
Each layer constituting the noncombustible sheet 10 will be described below. The contents of various materials described later refer to the content ratio (mass%) relative to the mass of the entire corresponding layer in a dry state. For example, the content of the inorganic material in this embodiment described later refers to the content ratio (mass%) relative to the mass of the entire raw fabric layer 1 in a dry state. The content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 described later refers to the content ratio (mass%) relative to the mass of the entire surface anchor layer 2 in a dry state. The content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5 described later refers to the content ratio (mass%) relative to the mass of the entire back anchor layer 5 in a dry state.

(Original layer)
The base fabric layer 1 is a layer (sheet) that serves as a base material for the noncombustible sheet 10, and is a layer that contains a thermoplastic resin and an inorganic material.
The content of the inorganic material in this embodiment may be in the range of 15% by mass to 90% by mass, more preferably in the range of 20% by mass to 80% by mass, and even more preferably in the range of 60% by mass to 80% by mass. If the content of the inorganic material is less than 15% by mass, the proportion of thermoplastic resin is relatively high, and it is difficult to obtain non-combustibility or flame retardancy. In addition, when the surface of the original layer 1 is scratched using a Hoffman scratch tester, visible scratches may be formed, that is, sufficient surface hardness may not be obtained. On the other hand, if the content of the inorganic material exceeds 90% by mass, the proportion of thermoplastic resin is relatively low. For this reason, when the surface of the original layer 1 is coated with an anchor layer or printed, so-called "powdering" may occur on the surface of the original layer 1. Here, "powdering" refers to the inorganic material contained in the original layer 1 protruding to the surface of the original layer 1. In addition, when forming the picture pattern layer 3, the inorganic material protruding from the original roll layer 1 may make it difficult to laminate the ink, i.e., the printability may decrease. In addition, when a sheet on which at least one of the surface anchor layer 2, the back anchor layer 5, the picture pattern layer 3, and the top coat layer 4 is formed is laminated to a wood-based substrate and a stone-based substrate in a roll or a sheet, it may become difficult to laminate, i.e., the lamination suitability may decrease. In addition, when a sheet on which at least one of the surface anchor layer 2, the back anchor layer 5, the picture pattern layer 3, and the top coat layer 4 is formed is folded and opened again, cracks may occur from the folded part or inorganic material may fall off. In addition, when cellophane tape is pressed onto the surface of the sheet on which the picture pattern layer 3 is formed, and then strongly peeled off, peeling may occur within the picture pattern layer 3 or between the original roll layer 1 (surface anchor layer 2) and the picture pattern layer 3, i.e., ink adhesion may decrease.

Thus, if the content of the inorganic material in this embodiment is within the range of 15% by mass to 90% by mass, preferably 20% by mass to 80% by mass, and more preferably 60% by mass to 80% by mass, relative to the mass of the original layer 1, it is possible to obtain non-flammability or flame retardancy, while reducing the occurrence of powdering, improving printability, improving lamination suitability, and reducing the occurrence of cracks in the folded portions of the sheet, and furthermore obtaining sufficient surface hardness and improving ink adhesion.

In addition, the inorganic material of this embodiment is preferably in a powder form (powder form), and its average particle diameter is preferably in the range of 1 μm or more and 3 μm or less, and its maximum particle diameter is preferably 50 μm or less. If the average particle diameter and maximum particle diameter of the inorganic material are within the above numerical range, the dispersibility of the inorganic material in the thermoplastic resin can be improved while maintaining the flatness of the surface of the raw fabric layer 1. If the average particle diameter of the inorganic material is less than 1 μm, the cohesive force between the inorganic materials increases, and the dispersibility in the thermoplastic resin described later may decrease. If the average particle diameter of the inorganic material exceeds 3 μm, the flatness of the surface of the raw fabric layer 1 may decrease, and the thickness of the surface anchor layer 2 or the back anchor layer 5 described later may become uneven, or unevenness or chipping may occur. If the maximum particle diameter of the inorganic material exceeds 50 μm, the flatness of the surface of the raw fabric layer 1 may decrease, and the thickness of the surface anchor layer 2 or the back anchor layer 5 described later may become uneven, or unevenness or chipping may occur. In this embodiment, the "average particle diameter" means the mode diameter.

The inorganic material is, for example, a powder containing at least one of calcium carbonate and calcium carbonate salt. The powder containing at least one of calcium carbonate and calcium carbonate salt is preferably one that contains at least 50% by mass and at most 100% by mass of calcium carbonate relative to the total mass of the powder. In other words, the purity of the powder containing at least one of calcium carbonate and calcium carbonate salt is preferably in the range of 50% by mass and at most 100% by mass of calcium carbonate, etc. Powder containing at least one of calcium carbonate and calcium carbonate salt with a content of calcium carbonate, etc. of 50% by mass or more can impart sufficient non-combustibility or sufficient flame retardancy to the raw fabric layer 1, as well as sufficient mechanical strength.

In addition to the powder containing at least one of the calcium carbonate and calcium carbonate salts, examples of the inorganic material include at least one of silica (particularly hollow silica), alumina, antimony trioxide, antimony soda, zirconium compounds such as zirconium silicate and zirconium oxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, borax, zinc borate, molybdenum trioxide or a complex of antimony dimolybdate and aluminum hydroxide, a complex of antimony trioxide and silica, a complex of antimony trioxide and zinc oxide, a silicic acid of zirconium, a complex of a zirconium compound and antimony trioxide, and salts thereof. In addition, the inorganic material may be, for example, limestone powder, sintered powder of egg shells, sintered powder of shells such as oysters and scallops, etc. Among the inorganic materials described above, calcium carbonate and calcium carbonate salts are particularly suitable from the viewpoint of reducing the cost of fireproof sheets, since it is easy to control the particle size and the compatibility with thermoplastic resins by the manufacturing method, and the material cost is also low.

The inorganic material may be a powder material having crystallinity, i.e., a so-called crystalline powder, or a powder material having no crystallinity, i.e., a so-called amorphous type powder material. If the inorganic material is a powder material having crystallinity, the powder itself is homogeneous and isotropic, so that the mechanical strength of the powder itself tends to be improved, and the scratch resistance and durability of the non-combustible sheet tend to be improved. If the inorganic material is a powder material of the amorphous type, it is possible to appropriately adjust the electrical conductivity and thermal conductivity of the powder itself, or the light transmittance and light absorbance, so that it is possible to impart a design with a wide variety of textures, gloss, etc.

The thermoplastic resin of this embodiment preferably contains at least one of polypropylene, polyethylene, and polyester, and more preferably contains polypropylene. By using at least one of polypropylene, polyethylene, and polyester as the thermoplastic resin, the dispersibility of the inorganic material is improved. Furthermore, by using polypropylene as the thermoplastic resin, the dispersibility of the inorganic material is further improved.

The total content of the thermoplastic resin and the inorganic material is preferably in the range of 90% by mass or more and 100% by mass or less with respect to the mass of the original layer 1. If the total content of the thermoplastic resin and the inorganic material is within the above numerical range, sufficient non-combustibility or sufficient flame retardancy can be obtained, while improving printability and lamination suitability, and cracks occurring at the folded parts of the sheet can be reduced. If the total content of the thermoplastic resin and the inorganic material is less than 90% by mass with respect to the mass of the original layer 1, sufficient non-combustibility or sufficient flame retardancy may not be obtained. Also, printability and lamination suitability may decrease, and cracks may occur at the folded parts of the sheet.

In addition, when the total content of the thermoplastic resin and the inorganic material is 100% by mass relative to the mass of the raw layer 1, it is preferable that the content of the thermoplastic resin is in the range of 10% by mass to 85% by mass, and the content of the inorganic material is in the range of 15% by mass to 90% by mass. It is more preferable that the content of the thermoplastic resin is in the range of 20% by mass to 80% by mass, and the content of the inorganic material is in the range of 20% by mass to 80% by mass. It is even more preferable that the content of the thermoplastic resin is in the range of 20% by mass to 40% by mass, and the content of the inorganic material is in the range of 60% by mass to 80% by mass. If the total content of the thermoplastic resin and the inorganic material is within the above numerical range, it is possible to reliably obtain sufficient non-flammability or sufficient flame retardancy, reliably improve printability and lamination suitability, and reliably reduce cracks that occur in the folded parts of the sheet.

In addition, the thickness of the original layer 1 is preferably in the range of 50 μm to 250 μm, more preferably in the range of 70 μm to 200 μm. If the thickness of the original layer 1 is within the above numerical range, it can improve lamination suitability and reduce cracks occurring at the folded part of the sheet. If the thickness of the original layer 1 is less than 50 μm, the lamination suitability tends to decrease. If the thickness of the original layer 1 is more than 250 μm, cracks may occur at the folded part of the sheet.
In addition, the raw fabric layer 1 is preferably a uniaxially or biaxially oriented raw fabric layer. If the raw fabric layer 1 is a uniaxially or biaxially oriented raw fabric layer, the versatility of the noncombustible sheet 10 can be improved.

In addition, it is preferable to perform a surface treatment such as corona treatment or plasma treatment on at least one of the front surface (first surface) and the back surface (second surface) of the raw fabric layer 1 before forming, for example, the front surface anchor layer (first anchor layer) 2 and the back surface anchor layer (second anchor layer) 5 described later. By performing a surface treatment such as corona treatment or plasma treatment on at least one of the front surface and the back surface of the raw fabric layer 1, the adhesion (adhesion) between the front surface anchor layer 2 and the back surface anchor layer 5 and the raw fabric layer 1 is improved.
In addition, before forming the surface anchor layer 2 and the back anchor layer 5, for example, at least one of the front and back surfaces of the raw fabric layer 1 may be brushed to remove powder containing at least one of the powdered inorganic material, such as calcium carbonate and calcium carbonate salt.

(Surface anchor layer)
The surface anchor layer 2 is a layer formed to cover the entire surface of the original layer 1, and is a layer for preventing the inorganic material contained in the original layer 1 from falling off. If the inorganic material contained in the original layer 1 falls off in the printing system, specifically in the printing device, during printing or resin coating, the printing system may be contaminated. In addition, if the inorganic material contained in the original layer 1 falls off, problems such as ink loss may occur. Here, "ink loss" refers to ink not being printed in parts.

The surface anchor layer 2 also has the function of improving the adhesion between the base fabric layer 1 and the ink forming the picture pattern layer 3 described below. If the surface anchor layer 2 is not provided, the ink forming the picture pattern layer 3 may not adhere to the base fabric layer 1 and may peel off.
The surface anchor layer 2 preferably contains a urethane resin containing vinyl chloride acetate, or an acrylic resin containing vinyl chloride acetate. Here, "vinyl chloride acetate" means a copolymer of vinyl chloride and vinyl acetate. Also, "urethane resin containing vinyl chloride acetate" means a composition containing vinyl chloride acetate and a urethane resin, and the ratio of the vinyl chloride acetate content to the urethane resin content (vinyl chloride acetate content (mass)/urethane resin content (mass)) may be within a range of 80/20 to 1/99, preferably within a range of 50/50 to 5/95, and more preferably within a range of 20/80 to 10/90.

The "urethane resin containing vinyl chloride acetate" may contain a hardener in addition to the vinyl chloride acetate and urethane resin described above. The hardener is added to ensure that the urethane resin containing vinyl chloride acetate is hardened, and its content is not particularly limited. For example, the ratio of the content of the urethane resin containing vinyl chloride acetate to the content of the hardener (content (mass) of the urethane resin containing vinyl chloride acetate/content (mass) of the hardener) may be within the range of 99/1 to 1/99, preferably within the range of 99/1 to 50/50, and more preferably within the range of 95/5 to 90/10.

The content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 is preferably in the range of 15% by mass to 100% by mass, more preferably in the range of 80% by mass to 100% by mass, and even more preferably in the range of 85% by mass to 95% by mass, relative to the mass of the surface anchor layer 2. If the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 is within the above numerical range, it is possible to form a surface anchor layer 2 that is uniform and free of unevenness and chipping while ensuring sufficient interlayer strength between the surface anchor layer 2 and the picture pattern layer 3. If the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 is less than 15% by mass relative to the mass of the surface anchor layer 2, the interlayer strength between the surface anchor layer 2 and the picture pattern layer 3 may be insufficient. In addition, if the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 is less than 80% by mass in a dry state relative to the mass of the surface anchor layer 2, there is no problem in use, but the bite ratio of the surface anchor layer 2 into the original fabric layer 1 decreases, and there is a slight possibility of a decrease in the interlayer strength between the surface anchor layer 2 and the original fabric layer 1. In addition, if the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 is 100% by mass or less relative to the mass of the surface anchor layer 2, there is no problem in use, but if it exceeds 95% by mass, more precisely 98% by mass, the surface anchor layer 2 may be chipped due to insufficient hardening, or the interlayer strength between the surface anchor layer 2 and the original fabric layer 1, or between the surface anchor layer 2 and the picture pattern layer 3 may decrease.

In addition, the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 may be the same as the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5 described later. That is, the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 may be 1.0 times (within the range of 0.95 times to 1.04 times) the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5. When the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 is the same as the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5, the physical properties of the surface anchor layer 2 and the physical properties of the back anchor layer 5 are almost the same, so that the occurrence of distortion, warping, etc. can be reduced in a state in which the original fabric layer 1 has the surface anchor layer 2 and the back anchor layer 5. Therefore, the occurrence of distortion, warping, etc. of the entire non-combustible sheet can be reduced. In addition, the coating liquid for forming the front surface anchor layer 2 and the coating liquid for forming the back surface anchor layer 5 can be made the same, which reduces manufacturing costs and improves work efficiency.

In addition, the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 may be greater or less than the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5. When the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 is greater or less than the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5, the physical properties of the surface anchor layer 2 and the back anchor layer 5 are different, so that the original fabric layer 1 having the surface anchor layer 2 and the back anchor layer 5 can be given distortion, warping, etc. In this way, by giving distortion, warping, etc. to the original fabric layer 1 having the surface anchor layer 2 and the back anchor layer 5, the original fabric layer 1 can be bonded to a substrate having a curved surface without any gaps. For example, the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the surface anchor layer 2 may be 1.1 times or more and 10 times or less, or 0.1 times or more and 0.9 times or less, of the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5.

The thickness of the surface anchor layer 2 is, for example, in the range of 0.5 μm to 20 μm, preferably in the range of 0.5 μm to 10 μm. The thickness of the surface anchor layer 2 may be the same as the thickness of the back anchor layer 5. When the thickness of the surface anchor layer 2 is the same as the thickness of the back anchor layer 5, the physical properties of the surface anchor layer 2 and the back anchor layer 5 are almost the same, so that when the original layer 1 has the surface anchor layer 2 and the back anchor layer 5, the occurrence of distortion, warping, etc. can be reduced.
In addition, the thickness of the surface anchor layer 2 may be thicker or thinner than the thickness of the back anchor layer 5. By making the thickness of the surface anchor layer 2 and the thickness of the back anchor layer 5 different, a gloss difference occurs, so that the surface side and the back side of the raw fabric layer 1 can be easily visually recognized. In this way, the picture pattern layer 3 can be printed on the surface of the raw fabric layer 1 without forming an identification mark or the like indicating that it is a printed surface. As a result, the product loss caused by forming the picture pattern layer 3 on the back (non-printed surface) side of the raw fabric layer 1 can be reduced.

(Pattern layer)
The picture pattern layer 3 is a layer that imparts a picture to the noncombustible sheet 10 and is formed on the surface anchor layer 2.
There are no particular restrictions on the type of picture pattern formed by the picture pattern layer 3, and for example, wood grain patterns, stone patterns, fabric patterns, abstract patterns, geometric figures, letters, symbols, etc. may be formed alone or in combination of two or more types.

The picture pattern layer 3 is a layer formed by applying an ink containing an acrylic resin as a binder (hereinafter also referred to as the ink for forming the picture pattern layer) to one side of the surface anchor layer 2. The acrylic resin contained as a binder in the ink for forming the picture pattern layer may be, for example, a resin whose main component is an acrylate copolymer resin, such as ethylene-methyl acrylate copolymer resin (EMA), ethylene-ethyl acrylate copolymer resin (EEA), ethylene-methacrylic acid copolymer resin (EMAA), ethylene-acrylic acid copolymer resin (EAA), ionomer resin, or a mixture thereof. Here, the "main component" refers to the component that is contained in the greatest amount among the components that make up the picture pattern layer 3.

The picture pattern layer 3 may be a layer formed by applying an ink containing a urethane resin as a binder to one side of the surface anchor layer 2. The urethane resin may be a urethane resin obtained by reacting an acrylic polyol with an isocyanate. The isocyanate may be appropriately selected from, for example, tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), methylhexane diisocyanate (HTDI), methylcyclohexanone diisocyanate (HXDI), trimethylhexamethylene diisocyanate (TMDI), etc., but in consideration of weather resistance, it is preferable to use hexamethylene diisocyanate (HMDI) having a linear molecular structure.

The ink for forming the pattern layer may contain, together with the acrylic resin, a crosslinking agent that crosslinks the acrylic resin. This crosslinking agent is also generally referred to as a "hardening agent" because it has the function of crosslinking the acrylic resin and imparting mechanical strength to the entire pattern layer 3. Examples of crosslinking agents (hardening agents) that can be added to the ink for forming the pattern layer include urethane hardening agents. More specifically, examples of urethane hardening agents that can be added to the ink for forming the pattern layer include IPDA (isophorone diamine) and HDI (hexamethylene diisocyanate). In this embodiment, these can be used alone or in combination.

When the ink for forming the picture pattern layer contains a crosslinking agent, the content of the crosslinking agent is preferably in the range of more than 0 parts by mass and not more than 10 parts by mass, assuming that the content of the acrylic resin in the picture pattern layer 3 is 100 parts by mass. If the content of the crosslinking agent is within the above numerical range, the coatability of the ink for forming the picture pattern layer is improved. Preferably, the content of the crosslinking agent is 3 parts by mass, assuming that the content of the acrylic resin in the picture pattern layer 3 is 100 parts by mass.
In addition to the binder, the ink for forming the picture pattern layer may contain, for example, organic or inorganic dyes or pigments, and if necessary, extender pigments, fillers, tackifiers, dispersants, antifoaming agents, stabilizers and other additives. The ink for forming the picture pattern layer is adjusted to a desired viscosity with a suitable diluting solvent.

There are no particular limitations on the method for forming the picture pattern layer 3, and any printing method can be used, such as gravure printing, offset printing, screen printing, flexographic printing, letterpress printing, inkjet printing, etc.
In addition, when a solid ink layer (not shown) is provided between the surface anchor layer 2 and the picture pattern layer 3 for the purpose of base coloring, in addition to the various printing methods described above, any coating method can be used to form the solid ink layer, such as roll coating, gravure coating, rod coating, knife coating, air knife coating, spray coating, lip coating, die coating, etc.

(Topcoat layer)
The top surface of the noncombustible sheet 10 is provided with a top coat layer 4 that serves to protect the surface and adjust the gloss. The thickness of the top coat layer 4 is preferably 2 μm or more and 10 μm or less. If the thickness of the top coat layer 4 is within the above range, it is possible to maintain flexibility while sufficiently obtaining mechanical properties such as abrasion resistance and surface hardness. If the thickness of the top coat layer 4 is less than 2 μm, it may be difficult to sufficiently obtain mechanical properties such as abrasion resistance and surface hardness. Furthermore, if the thickness of the top coat layer 4 exceeds 10 μm, flexibility may decrease.
The resin material that is the main component of the topcoat layer 4 can be appropriately selected from polyurethane, acrylic silicone, fluorine, epoxy, vinyl, polyester, melamine, aminoalkyd, urea, and other resin materials. The form of the resin material is not particularly limited, and may be water-based, emulsion, solvent-based, or the like. The curing method may also be appropriately selected from one-liquid type, two-liquid type, ultraviolet curing method, and the like.

As the resin material that is the main component of the topcoat layer 4, a urethane-based material using isocyanate is suitable from the viewpoints of workability, cost, and the cohesive strength of the resin itself. The isocyanate can be appropriately selected from curing agents such as adducts, biuret, and isocyanurates, which are derivatives of tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), bis(isocyanatemethyl)cyclohexane (HXDI), and trimethylhexamethylene diisocyanate (TMDI). However, in consideration of weather resistance, a curing agent based on hexamethylene diisocyanate (HMDI) or isophorone diisocyanate (IPDI), which has a linear molecular structure, is suitable. In addition, when trying to improve the surface hardness, it is preferable to use a resin that is cured by active energy rays such as ultraviolet rays or electron beams. These resins can be used in combination with each other. For example, by using a hybrid type of thermosetting and photocuring, it is possible to improve the surface hardness, suppress the cure shrinkage, and improve the adhesion.

In addition, ultraviolet absorbers and light stabilizers may be added as appropriate to improve the weather resistance of the non-combustible sheet 10. Functional additives such as antibacterial agents and antifungal agents may also be added as needed to impart various functions. Furthermore, alumina, silica, silicon nitride, silicon carbide, glass beads, etc. may also be added as needed to adjust the gloss of the surface design or to impart further abrasion resistance.

(Back anchor layer)
The back anchor layer 5 is a layer formed so as to cover the entire back surface of the original fabric layer 1, and is a layer for preventing powder falling off of the inorganic material contained in the original fabric layer 1. If the inorganic material contained in the original fabric layer 1 powders off in the printing system, specifically in the printing device, during printing or resin coating, the printing system may be contaminated.
The back anchor layer 5 also has a function of improving adhesion between the original fabric layer 1 and a primer layer 6 described later. If the back anchor layer 5 is not provided, the coating liquid forming the primer layer 6 may not adhere to the original fabric layer 1 and may peel off.
The back surface anchor layer 5 preferably contains a urethane resin containing vinyl chloride and acetate, or an acrylic resin containing vinyl chloride and acetate.

The content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5 is, for example, preferably in the range of 15% by mass to 100% by mass, more preferably in the range of 80% by mass to 100% by mass, and even more preferably in the range of 85% by mass to 95% by mass, relative to the mass of the back anchor layer 5. If the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5 is within the above numerical range, the back anchor layer 5 can be formed uniformly without unevenness or chipping while ensuring sufficient interlayer strength between the back anchor layer 5 and the primer layer 6. If the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5 is less than 15% by mass relative to the mass of the back anchor layer 5, the interlayer strength between the back anchor layer 5 and the primer layer 6 may be insufficient. In addition, if the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5 is less than 80% by mass relative to the mass of the back anchor layer 5, there is no problem in use, but the biting ratio of the back anchor layer 5 into the original fabric layer 1 decreases, and there is a slight decrease in the interlayer strength between the back anchor layer 5 and the original fabric layer 1. In addition, if the content of the urethane resin containing vinyl chloride acetate or the acrylic resin containing vinyl chloride acetate in the back anchor layer 5 is 100% by mass or less relative to the mass of the back anchor layer 5, there is no problem in use, but if it exceeds 95% by mass, more precisely 98% by mass, the back anchor layer 5 may be chipped due to insufficient hardening, or the interlayer strength between the back anchor layer 5 and the original fabric layer 1, or between the back anchor layer 5 and the picture pattern layer 3 may decrease.
The thickness of the back surface anchor layer 5 is, for example, in the range of 0.5 μm to 20 μm, and preferably in the range of 0.5 μm to 10 μm.

(Primer layer)
As the material of the primer layer 6, for example, nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyester, etc. as a binder, or modified products thereof can be appropriately selected and used. These can be in any form, such as water-based, solvent-based, or emulsion type. In addition, the curing method can be appropriately selected and used from a one-liquid type that cures alone, a two-liquid type that uses a curing agent in combination with a base agent, and a type that cures by irradiation with ultraviolet rays or electron beams. A two-liquid type that cures by combining an isocyanate-based curing agent with a urethane-based base agent is generally used as a curing method, and this method is suitable from the viewpoints of workability, cost, and cohesive force of the resin itself. In addition to the above-mentioned binders, colorants such as pigments and dyes, extender pigments, solvents, and various additives are added. In particular, since the primer layer 6 is located on the back surface of the noncombustible sheet 10, taking into consideration that the noncombustible sheet 10 is wound up as a continuous plastic film (web-like), inorganic fillers such as silica, alumina, magnesia, titanium oxide, barium sulfate, etc. may be added to the primer layer 6 in order to prevent blocking, such as films adhering to each other and becoming difficult to slide or unable to peel off, and to improve adhesion to the adhesive. The layer thickness is preferably set within the range of 0.1 μm to 3.0 μm, since the purpose is to ensure adhesion to the substrate 11 described later.

(Adhesive resin layer)
The fireproof sheet 10 of this embodiment may include an adhesive resin layer (not shown) between the picture pattern layer 3 and the top coat layer 4 or the transparent resin layer 7 described later. By providing the adhesive resin layer, the adhesion between the picture pattern layer 3 and the top coat layer 4 can be improved. The material of the adhesive resin layer is not particularly limited, but can be appropriately selected from acrylic, polyester, polyurethane, epoxy, etc. The coating method can be appropriately selected depending on the viscosity of the adhesive, but generally, gravure coating is used, and the adhesive is applied onto the picture pattern layer 3 by gravure coating, and then laminated with the top coat layer 4 or the transparent resin layer 7 to form the adhesive layer.

[Method of manufacturing non-combustible sheet]
An example of a method for manufacturing the noncombustible sheet 10 will now be briefly described.
First, a surface anchor layer forming ink for forming a surface anchor layer 2 is applied to one surface of the base layer 1 to form the surface anchor layer 2 .
Next, a picture pattern layer forming ink for forming the picture pattern layer 3 is applied onto the surface of the surface anchor layer 2 to form the picture pattern layer 3 .
Next, a topcoat layer forming ink is applied onto the surface of the picture design layer 3 to form a topcoat layer 4 .
Next, a back surface anchor layer forming ink is applied to the back surface, which is the other surface of the original layer 1, to form the back surface anchor layer 5.
Finally, a primer layer forming ink is applied onto the surface of the back surface anchor layer 5 to form a primer layer 6 , thereby forming the primer layer 6 .
In this manner, the noncombustible sheet 10 according to the present embodiment is manufactured.
The back anchor layer 5 may be formed simultaneously with the front anchor layer 2. The primer layer 6 may be formed before the picture pattern layer 3 and the top coat layer 4 are formed.

[Composition of non-combustible materials]
The configuration of the non-combustible material 12 will be described with reference to FIG.
1, the noncombustible material 12 includes a substrate 11 and the above-mentioned noncombustible sheet 10. Hereinafter, the substrate 11 will be described, and a description of the above-mentioned noncombustible sheet 10 will be omitted.

(substrate)
The substrate 11 of the present embodiment is a plate-like member formed using, for example, a metal-based material, a wood-based material, or an inorganic material.
Examples of metal materials that can be used include aluminum, steel, stainless steel, composite panels, and the like.
As a composite panel, for example, one having a resin layer as a core material and metal plates (aluminum, galvalume, stainless steel, etc.) attached to both sides of the resin layer can be used.
Examples of wood-based materials that can be used include MDF (Medium Density Fiberboard), plywood, and particle board.
As inorganic materials, for example, gypsum board, fiber-mixed calcium silicate board, etc. can be used.

[Method of manufacturing non-combustible materials]
An example of a method for producing the noncombustible material 12 will now be briefly described.
First, the primer layer 6 of the noncombustible sheet 10 is placed facing the substrate 11 .
This stack is then, for example, heat laminated.
In this manner, the primer layer 6 and the substrate 11 are welded together to produce the noncombustible material 12 .
As a method for thermally laminating the laminate, in addition to a method of pressing the laminate with a metal plate, a continuous lamination method using a circular pressure can also be used. In particular, the continuous lamination method using a metal endless belt or a metal or hardening resin heat drum has the advantage that there is no warping or waviness on the surface, and the adhesion between the layers is good, and a high-quality noncombustible material 12 that is densely hardened and integrated can be continuously produced at high speed.

Here, the technical standards for noncombustible materials stipulated in the Enforcement Order of the Building Standards Act require that the following requirements be met in a heat generation test using a cone calorimeter tester conforming to ISO 5660-1 (Article 108-2, Items 1 and 2 of the Enforcement Order of the Building Standards Act). In order for the noncombustible sheet 10 of this embodiment to be certified as a noncombustible material, it must satisfy all of the following requirements 1 to 3 when heated for 20 minutes by radiant heat of 50 kW/ ^m2 in a state where it is laminated to a noncombustible substrate.
1. The total heat generation amount is 8 MJ/ ^m2 or less. 2. The maximum heat generation rate does not exceed 200 kW/ ^m2 for 10 seconds or more. 3. No cracks or holes that penetrate to the back surface and are harmful in terms of flame retardancy are generated. The non-combustible base material can be selected from gypsum board, fiber-mixed calcium silicate board, or galvanized steel plate.

The non-combustible sheet 10 of this embodiment, which includes the aforementioned base fabric layer 1, is a non-combustible material that satisfies both of the requirements set forth in Article 108-2, Items 1 and 2 of the Enforcement Order when subjected to a heat generation test using a cone calorimeter tester conforming to ISO 5660-1 when bonded to the aforementioned non-combustible substrate.

<Modification>
In the present embodiment, the top coat layer 4 is a single layer, but may be a multi-layer. Hereinafter, a case in which the top coat layer 4 includes two layers, a first top coat layer 4a and a second top coat layer 4b, will be described.
As shown in Fig. 2, the first topcoat layer 4a is provided on the surface side of the picture pattern layer 3, and is a layer that covers the entire picture pattern layer 3. The first topcoat layer 4a is formed of a transparent or semi-transparent material (resin) to such an extent that the picture of the picture pattern layer 3 can be seen through the first topcoat layer 4a. The first topcoat layer 4a may be a single layer or a layer formed by stacking multiple layers. In addition, the thickness of the first topcoat layer 4a is preferably within a range of, for example, 2 µm to 10 µm.

The second topcoat layer 4b is a layer that is partially provided on the surface side of the first topcoat layer 4a and covers a part of the surface of the first topcoat layer 4a. An example of the part of the surface of the first topcoat layer 4a is the part facing the printing ink of the picture pattern layer 3. The material of the second topcoat layer 4b can be, for example, the same resin as that of the first topcoat layer 4a. A filler may be added to the second topcoat layer 4b. By adding a filler, it is possible to impart mechanical properties such as gloss, touch, texture, surface strength, and friction that are different from those of the first topcoat layer 4a. As the filler, for example, a material that consumes less oxygen during combustion is preferable, and examples thereof include calcium carbonate, antimony trioxide, antimony soda, zirconium compounds such as zirconium silicate and zirconium oxide, magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate, borax, zinc borate, molybdenum trioxide or a complex of antimony dimolybdate and aluminum hydroxide, a complex of antimony trioxide and silica, a complex of antimony trioxide and zinc oxide, a silicic acid of zirconium, and a complex of a zirconium compound and antimony trioxide. In particular, calcium carbonate is easy to control the particle size by a manufacturing method and the compatibility with a polyolefin resin by a surface treatment, and is also suitable from the viewpoint of reducing the cost of a decorative sheet because it is inexpensive in terms of material cost. In addition, beads or amorphous particles of resins such as acrylic, polyolefin, and silicone, and beads or amorphous particles of inorganic substances such as silica (especially hollow silica), alumina, and metal oxides can be used. In addition, the method of forming the second top coat layer 4b is not particularly limited, and a known printing method can be adopted. The second topcoat layer 4b is also commonly referred to as the "tactile coating layer" or "matte duct printing layer."

Second Embodiment
[Configuration of fireproof sheet]
As shown in FIG. 3, the non-combustible sheet 10 of the second embodiment includes, from the back side to the front side, a primer layer 6, a back anchor layer 5, a raw fabric layer 1, a front anchor layer 2, a picture pattern layer 3, a transparent resin layer 7, and a top coat layer 4. The top coat layer 4 of the second embodiment includes a first top coat layer 4a and a second top coat layer 4b. The non-combustible material 12 of the second embodiment includes the non-combustible sheet 10 of the second embodiment and a substrate 11. That is, the non-combustible sheet 10 of the second embodiment is different from the non-combustible sheet 10 of the first embodiment in that it includes a transparent resin layer 7 and a top coat layer 4 consisting of multiple layers. Therefore, hereinafter, the transparent resin layer 7 and the top coat layer 4 consisting of multiple layers, which are different parts, will be described, and the other layers will not be described.

(Transparent resin layer)
The transparent resin layer 7 is a sheet-like layer formed using a transparent resin so that the design of the picture pattern layer 3 can be seen through it, and is laminated on the upper surface of the picture pattern layer 3.
As a method for laminating the transparent resin layer 7, for example, a method in which the transparent resin layer 7 is laminated onto a laminate including the original fabric layer 1, the surface anchor layer 2, and the picture pattern layer 3 by lamination processing can be used.
The transparent resin forming the transparent resin layer 7 is not particularly limited, and any known transparent resin can be used.

Therefore, examples of the transparent resin that forms the transparent resin layer 7 include polyolefin resins, ethylene-vinyl acetate copolymers or saponification products thereof, polyolefin copolymers, polyester resins, acrylic resins such as polymethyl methacrylate, polyamide resins, styrene resins, cellulose derivatives, chlorine-based resins, fluorine-based resins, etc., which may be used alone or in the form of a mixture, copolymer, composite, laminate, etc. of two or more types selected from these materials.
In particular, in the case of production using a melt extrusion device, taking into consideration productivity, environmental compatibility, mechanical strength, durability, cost, etc., it is more preferable to use a polyolefin-based resin as the transparent resin that forms the transparent resin layer 7.

Examples of polyolefin resins that can be used include polyethylene, polypropylene, polybutene, and polymethylpentene, with polypropylene being the most preferable. Examples of polyolefin copolymers that can be used include ethylene-(meth)acrylic acid (ester) copolymers.
Examples of polyester-based resins that can be used include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyarylate, polycarbonate, and copolymerized polyester (typically, 1,4-cyclohexanedimethanol copolymerized polyethylene terephthalate resin, commonly known as PET-G).
As the polyamide resin, for example, 6-nylon, 6,6-nylon, 6,10-nylon, 12-nylon, etc. can be used.
As the styrene-based resin, for example, polystyrene, AS resin, ABS resin, etc. can be used.

As the cellulose derivative, for example, cellulose acetate, nitrocellulose, etc. can be used.
As the chlorine-based resin, for example, polyvinyl chloride, polyvinylidene chloride, etc. can be used.
As the fluorine-based resin, for example, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, etc. can be used.

In order to ensure that the transparent resin layer 7 has both good strength and transparency, the thickness of the transparent resin layer 7 is preferably in the range of 20 μm to 150 μm, and more preferably in the range of 45 μm to 90 μm.
The transparent resin layer 7 may contain various additives such as existing heat stabilizers, flame retardants, ultraviolet absorbers, light stabilizers, antiblocking agents, catalyst traps, colorants, light scattering agents, and gloss adjusters, if necessary. In order to improve the surface strength, it is preferable to use a highly crystalline polypropylene resin. As the heat stabilizer, for example, a phenol-based, sulfur-based, phosphorus-based, or hydrazine-based agent may be used. As the flame retardant, for example, aluminum hydroxide or magnesium hydroxide may be used. As the ultraviolet absorber, for example, a benzotriazole-based, benzoate-based, benzophenone-based, or triazine-based agent may be used. As the light stabilizer, for example, a hindered amine-based agent may be used. In addition, an embossed pattern 7a having a predetermined uneven pattern as shown in FIG. 3 may be formed on the surface of the transparent resin layer 7 as necessary.

(Embossed pattern)
The embossed pattern 7a is, for example, a pattern consisting of recesses and protrusions in sync with the pattern of the picture pattern layer 3. The recesses and protrusions of the embossed pattern 7a can impart a three-dimensional feel to the touch. The deviation between the embossed pattern 7a and the pattern of the picture pattern layer 3 is preferably within a range of, for example, 10 mm or less in the longitudinal direction and 3 mm or less in the transverse direction (width direction) of the shape of the picture pattern. For example, when the picture pattern is wood grain, the direction in which the conduits of the wood grain extend is the "longitudinal direction of the shape of the picture pattern", and the direction perpendicular to the longitudinal direction is the "transverse direction of the shape of the picture pattern". In particular, when the conduits of the wood grain extend along the longitudinal direction of the non-combustible sheet 10, the longitudinal direction of the non-combustible sheet 10 is the "longitudinal direction of the shape of the picture pattern", and the transverse direction (width direction) of the non-combustible sheet 10 is the "transverse direction of the shape of the picture pattern". The embossed pattern 7a is only strongly visible due to the reflection of oblique light, since the transparent resin layer 7 and the topcoat layer 4 are transparent. However, if the deviation between the embossed pattern 7a and the pattern of the picture pattern layer 3 is within the above range, it is difficult to visually recognize the reflected light and the transmitted light of the picture pattern layer 3 at the same time, so there is no sense of incongruity. By suppressing the deviation between the embossed pattern 7a and the pattern of the picture pattern layer 3 within a certain range, a non-combustible sheet 10 can be obtained in which the pattern shape and distribution are equal and matched accurately over the entire sheet surface. In addition, the height difference between the concave and convex parts of the embossed pattern 7a is, for example, within a range of 3 μm to 200 μm. The height difference can be selected to be a value suitable for the design of the desired non-combustible sheet 10. For example, a continuous multi-step shape can be obtained within the maximum height difference (200 μm). In particular, in order to obtain a shape as a macroscopic three-dimensional object, the height difference is more preferably in a range of 10 μm to 150 μm.

(Topcoat Layer)
The top coat layer 4 includes a first top coat layer 4a and a second top coat layer 4b.
The first topcoat layer 4a is provided on the surface side of the transparent resin layer 7, and is a layer that covers the entire transparent resin layer 7. The first topcoat layer 4a is formed of a transparent or semi-transparent material (resin) that allows the pattern of the picture pattern layer 3 to be seen through the first topcoat layer 4a. The first topcoat layer 4a may be a single layer, or a layer formed by stacking multiple layers. The thickness of the first topcoat layer 4a is preferably in the range of 3 μm to 100 μm, for example, from the viewpoint of completely filling the embossed pattern 7a and obtaining sufficient strength to protect the surface of the transparent resin layer 7 without impairing the design. Furthermore, as the material of the first topcoat layer 4a, for example, a thermosetting resin is preferable in terms of adhesion to the transparent resin layer 7, deformation followability of the non-combustible sheet 10, scratch resistance, etc. In particular, from the viewpoint of cost and versatility, a thermosetting resin (binder) having a urethane bond, such as a two-component curing urethane resin, is more preferable. The thermosetting resin may contain, for example, a matting agent such as silica particles or a scratch-resistant agent.

The two-component curing urethane resin may be, for example, a urethane resin that is mainly made of polyol and uses isocyanate as a crosslinking agent (curing agent). The polyol may have two or more hydroxyl groups in the molecule, and may be, for example, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, or polyurethane polyol.
As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in the molecule can be used. For example, aromatic isocyanates such as 2,4-tolylene diisocyanate, xylylene diisocyanate, and 4,4'-diphenylmethane diisocyanate, or aliphatic (or alicyclic) isocyanates such as 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate can be used. In addition, an adduct or multimer of the above various isocyanates can be used. For example, there is an adduct of tolylene diisocyanate, a tolylene diisocyanate trimer, and the like. Among the above isocyanates, aliphatic (or alicyclic) isocyanates are preferable in that they can provide good weather resistance and heat yellowing resistance, and for example, 1,6-hexamethylene diisocyanate can be used.

In addition, when scratch resistance is important, ionizing radiation curable resins are preferred from the viewpoint of hardness. As the ionizing radiation curable resin, for example, an ultraviolet curable resin can be used. For example, (meth)acrylic resin, silicone resin, polyester resin, urethane resin, amide resin, or epoxy resin can be used. By using an ultraviolet curable resin, the hardness of the top coat layer 4, that is, the outermost layer of the noncombustible sheet 10, can be improved, and the surface properties of the noncombustible sheet 10, such as abrasion resistance, scratch resistance, and solvent resistance, can be improved. In addition, as the material for the first top coat layer 4a, for example, a mixture of a thermosetting resin and an ionizing radiation curable resin can be used.

The second topcoat layer 4b is a layer that is partially provided on the surface side of the first topcoat layer 4a and covers a part of the surface of the first topcoat layer 4a. An example of a part of the surface of the first topcoat layer 4a is a part that faces the printing ink of the picture pattern layer 3. The material of the second topcoat layer 4b can be, for example, the same resin as that of the first topcoat layer 4a. A filler may be added to the second topcoat layer 4b. By adding a filler, it is possible to impart mechanical properties such as gloss, touch, texture, surface strength, and friction that are different from those of the first topcoat layer 4a. As the filler, for example, beads or amorphous particles of resin such as acrylic, polyolefin, or silicone, or beads or amorphous particles of inorganic substances such as silica, alumina, or metal oxide can be used. The method of forming the second topcoat layer 4b is not particularly limited, and known printing methods can be adopted. The second topcoat layer 4b is also generally called a "touch coat layer" or a "matt duct printing layer".

The above-described embodiment is an example of the present invention, and the present invention is not limited to the above-described embodiment. Various modifications can be made to the design, etc., even if the embodiment is different from the above-described embodiment, as long as the modifications do not deviate from the technical concept of the present invention.

[Example]
First, a raw fabric layer was formed, which was composed of calcium carbonate powder, an inorganic material, and polypropylene resin, a thermoplastic resin. The composition ratio of the raw fabric layer was 60% by mass of calcium carbonate powder and 40% by mass of polypropylene resin. The thickness of the raw fabric layer was 200 μm. The purity of the calcium carbonate powder used was 90% by mass. The calcium carbonate powder used had an average particle diameter (mode diameter) of 2 μm and a maximum particle diameter of 50 μm or less.
Next, the front and back surfaces of the raw layer were subjected to a corona treatment.

Next, a urethane-based anchor layer forming ink containing vinyl chloride acetate was applied to the front and back surfaces of the corona-treated original layer so that the coating thickness was 1 μm to 2 μm, and then dried at a drying temperature of 40° C. for 30 seconds. Thus, an anchor layer was formed on the front and back surfaces of the original layer. The content of the urethane-based resin containing vinyl chloride acetate and the content of the acrylic resin containing vinyl chloride acetate in the ink for forming the anchor layer used in each example and each comparative example are as shown in Table 1 below. The urethane-based resin containing vinyl chloride acetate and the acrylic resin containing vinyl chloride acetate are shown in "mass %" relative to the mass of the entire anchor layer. In addition, the urethane-based resin containing vinyl chloride acetate was one in which the mass ratio of vinyl chloride acetate to the urethane-based resin (vinyl chloride acetate:urethane-based resin) was 20:80. In addition, the acrylic resin containing vinyl chloride acetate was one in which the mass ratio of vinyl chloride acetate to the acrylic resin (vinyl chloride acetate:acrylic resin) was 20:80.

The ratio of the mass of vinyl chloride acetate to the mass of the urethane resin (mass of vinyl chloride acetate/mass of urethane resin) in the ink for forming the anchor layer used in each Example and Comparative Example is as shown in Table 2 below.
Next, a urethane-based ink for forming a pattern layer was applied (printed) onto the anchor layer on the surface side of the original fabric layer so that the coating thickness was 1 μm to 2 μm, and dried at a drying temperature of 40° C. for 30 seconds. In this way, a pattern layer was formed on the anchor layer on the surface side of the original fabric layer.
Thereafter, the laminate (sheet) comprising the raw fabric layer, the anchor layer and the picture design layer was aged at room temperature for one day to prepare a sample for each evaluation.
The evaluation items in this example are as follows.

<Ink adhesion>
After applying pressure to the surface of the printed sheet with cellophane tape manufactured by Nichiban, the tape was strongly peeled off with a certain amount of force, and the presence or absence of peeling within the design layer or between the original layer and the design layer was evaluated visually. The evaluation criteria were as follows:
⊚: When peeled off with a force of 15 N (Newtons), no peeling occurred within the picture design layer or between the original fabric layer and the picture design layer. ◯: When peeled off with a force of 10 N, no peeling occurred within the picture design layer or between the original fabric layer and the picture design layer. △: When peeled off with a force of 10 N, peeling occurred within the picture design layer or in part between the original fabric layer and the picture design layer. ×: The picture design layer adheres to the entire surface of the cellophane tape, and significant peeling occurred within the picture design layer or between the original fabric layer and the picture design layer.

<Printability>
During printing, the ink was visually inspected to see whether it was properly laminated without powder falling off the original layer. The evaluation criteria were as follows:
○: No clogging due to powder falling occurs, and it is possible to form a uniform, evenly coated surface without unevenness or omissions. △: Depending on the printing conditions or the equipment conditions of the printing machine, clogging, unevenness, or omissions due to powder falling occurs. ×: Clogging due to powder falling occurs, or it is extremely difficult to form a uniform coated surface.

<Powdering of the surface after printing>
The surface of the printed sheet was dry rubbed with hands or cotton, and the presence or absence of powdering or falling off of calcium carbonate powder was visually evaluated. The evaluation criteria were as follows:
○: No calcium carbonate powder was found on the surface of the hand or the surface of the cotton. △: Calcium carbonate powder was found on part of the surface of the hand or the surface of the cotton. ×: Calcium carbonate powder was found on the entire surface of the hand or the surface of the cotton.

<Non-flammability test>
In a heat generation test using a cone calorimeter tester in accordance with ISO 5660-1, it was evaluated whether the following requirements were met.
1. The total heat generation amount is 8 MJ/ ^m2 or less. 2. The maximum heat generation rate does not exceed 200 kW/ ^m2 for 10 seconds or more. 3. No cracks or holes penetrating to the back surface that are harmful in terms of fire prevention are generated. Note that gypsum board was used as the non-combustible base material. The evaluation criteria are as follows.
◯: Meets all of the above requirements. ×: Does not meet at least one of the above requirements. In each of the above evaluations, a sheet rated as "×" was deemed to have failed as a whole sheet.

As described above, a sheet comprising an original fabric layer 1, a surface anchor layer 2 formed on the surface of the original fabric layer 1, and a back anchor layer 5 formed on the back surface of the original fabric layer 1, in which the original fabric layer 1 contains a thermoplastic resin and an inorganic material, and the surface anchor layer 2 contains a urethane resin containing vinyl chloride and acetate, or an acrylic resin containing vinyl chloride and acetate, in a range of 15% by mass to 100% by mass relative to the total mass of the surface anchor layer 2, can prevent powdering of the inorganic material contained in the original fabric layer 1 while retaining non-flammability, and can improve the interlayer strength between the original fabric layer 1 and the picture pattern layer 3.

Reference Signs List 1 Raw fabric layer 2 Surface anchor layer 3 Picture pattern layer 4 Topcoat layer 4a First topcoat layer 4b Second topcoat layer 5 Back anchor layer 6 Primer layer 7 Transparent resin layer 7a Embossed pattern 10 Noncombustible sheet 11 Substrate 12 Noncombustible material

Claims (11)

The present invention comprises an original fabric layer, a first anchor layer formed on a first surface of the original fabric layer, and a second anchor layer formed on a second surface of the original fabric layer, the second surface being a surface opposite to the first surface,
The raw fabric layer contains a thermoplastic resin and an inorganic material,
The first anchor layer contains an acrylic resin including vinyl chloride and acetate in a range of 15% by mass or more and 100% by mass or less with respect to the total mass of the first anchor layer,
The second anchor layer contains an acrylic resin including vinyl chloride and acetate in an amount of 15% by mass or more and 100% by mass or less with respect to the total mass of the second anchor layer,
The content of the inorganic material is in the range of 15% by mass or more and 90% by mass or less with respect to the mass of the raw fabric layer,
The inorganic material is in a powder form, has an average particle size in the range of 1 μm to 3 μm, and has a maximum particle size of 50 μm or less;
The thermoplastic resin contains polypropylene,
A noncombustible sheet, wherein the first anchor layer and the second anchor layer each contain no inorganic material. The non-flammable sheet according to claim 1, characterized in that the first anchor layer contains an acrylic resin including vinyl chloride and acetate in a range of 80 mass% or more and 100 mass% or less relative to the total mass of the first anchor layer. The non-flammable sheet according to claim 1 or claim 2, characterized in that the second anchor layer contains an acrylic resin including vinyl chloride acetate in a range of 80 mass% or more and 100 mass% or less relative to the total mass of the second anchor layer . The non-flammable sheet according to any one of claims 1 to 3, characterized in that the content of the acrylic resin containing vinyl chloride and acetate in the first anchor layer is the same as the content of the acrylic resin containing vinyl chloride and acetate in the second anchor layer. The non-flammable sheet according to any one of claims 1 to 3, characterized in that the content of the acrylic resin containing vinyl chloride and acetate in the first anchor layer is greater than the content of the acrylic resin containing vinyl chloride and acetate in the second anchor layer. The non-flammable sheet according to any one of claims 1 to 3, characterized in that the content of the acrylic resin containing vinyl chloride and acetate in the first anchor layer is less than the content of the acrylic resin containing vinyl chloride and acetate in the second anchor layer. The non-flammable sheet according to any one of claims 1 to 6, wherein the thermoplastic resin further contains at least one of polyethylene and polyester. The non-flammable sheet according to any one of claims 1 to 7 , characterized in that the total content of the thermoplastic resin and the inorganic material is in the range of 90 mass% or more and 100 mass% or less relative to the mass of the original fabric layer. The non-combustible sheet according to any one of claims 1 to 8 , comprising the base layer, the first anchor layer, a picture pattern layer, and a top coat layer in this order. The noncombustible sheet according to any one of claims 1 to 9, comprising the base layer, the second anchor layer, and a primer layer in this order. The non-flammable sheet according to any one of claims 1 to 10 , characterized in that it satisfies the requirements for obtaining non-flammability certification in a heat generation test conforming to ISO 5660-1.

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