JP7775367B2 - Non-flammable wall sheet - Google Patents

Description

The present invention relates to a non-combustible wall sheet that is applied to the wall surfaces of buildings.

Conventionally, interior materials having non-combustible properties have been known to prevent fire outbreaks and to take safety into consideration in the event of a fire. Non-combustible properties refer to the property of being difficult to burn, and one of the known indicators of such properties is the ability to satisfy the following conditions based on the Building Standards Act:
Specifically, in a heat generation test in which radiant heat of 50 kW/ ^m2 is irradiated onto the surface of the material from a radiant electric heater, the following conditions must be met: (1) the total heat generation amount for 20 minutes after heating begins is 8 MJ/ ^m2 or less; (2) there are no cracks or holes that penetrate to the back surface and are harmful from a fire prevention perspective for 20 minutes after heating begins; and (3) the maximum heat generation rate does not exceed 200 kW/ ^m2 for 10 seconds or more for 20 minutes after heating begins.
The evaluation methods for (1) to (3) are stipulated in the Building Standards Act, which was revised in 2000, and interior materials that meet the performance requirements of (1) to (3) can be certified as non-combustible by the Minister of Land, Infrastructure, Transport and Tourism. Hereinafter, non-combustible performance that meets all of the requirements of (1) to (3) above will be referred to as "certified non-combustible performance."

Patent Document 1 discloses a fire-resistant sheet having the above-mentioned fire-resistant approved performance.
Specifically, Patent Document 1 discloses a non-combustible sheet material for building materials, in which a resin layer is provided on at least one side of a glass fiber fabric woven using glass fiber yarns as warp and weft, the resin layer of the non-combustible sheet material being a soft vinyl chloride resin layer with a resin amount of 300 to 700 g/ ^m2 , the thickness of the entire non-combustible sheet material being 0.45 mm or more, the air permeability of the glass fiber fabric being 7 ^cm3 × cm- ² × s- ¹ or less, the total density of the warp and weft of the glass fiber fabric being 59 threads/25 mm or more, both the glass fiber yarns of the warp and the glass fiber yarns of the weft being double-twisted yarns, and at least one of the glass fiber yarns of the warp and the weft being a double-twisted yarn twisted with a twist count of 3 turns/25 mm or less.
The fire-retardant sheet material in Patent Document 1 is a glass fiber fabric made of specific twisted yarns and having a total density of 59 strands/25 mm or more, and has an air permeability of 7 ^cm3 × cm- ² × s- ¹ or less. By providing a soft vinyl chloride resin layer of 300 to 700 g/ ^m2 on at least one side of the glass fiber fabric, flames, smoke, toxic gases, etc. generated in a fire hardly pass through the glass fiber fabric to the other side, and has very high fire and smoke resistance.

Japanese Patent Application Laid-Open No. 2003-276113

Incidentally, non-combustible sheets that have certified non-combustible performance meet the aforementioned conditions (1) to (3) based on the Building Standards Act, but considering the occurrence of a fire, it is preferable that the total heat generation be smaller.
Furthermore, since wall sheets applied to wall surfaces may come into contact with objects such as dollies, they must be designed to be resistant to gouges and holes caused by such contact. Hereinafter, gouges and holes will be collectively referred to as "damage."
The non-combustible sheet in Patent Document 1 does not take design into consideration at all, and if a separate design layer is added to the non-combustible sheet in Patent Document 1, the total heat generation will increase, and furthermore, the multi-layer structure will make it more susceptible to damage.

The object of the present invention is to provide a decorative wall sheet that is non-combustible, has a low total heat output, and is resistant to damage.

The noncombustible wall sheet of the present invention comprises a sheet body layer having a thickness of more than 0.25 mm but less than 0.50 mm, a design layer laminated on the surface of the sheet body layer, and a glass fiber layer laminated on the back side of the sheet body layer, wherein the sheet body layer contains a resin component containing chlorinated vinyl chloride , an inorganic filler, and a plasticizer, and the inorganic filler accounts for 40% to 80% by weight when the entire sheet body layer is taken as 100% by weight, and the plasticizer contains a phosphate ester, an adipate ester, dioctyl phthalate, dibutyl phthalate, butyl octyl phthalate, dioctyl isophthalate, diisononyl phthalate, or di-2-ethylhexyl terephthalate, and in a heat generation test in which radiant heat of 50 kW/m2 is irradiated onto the sheet surface from a radiant electric heater, ^the total heat generation amount for 20 minutes after heating begins is less than 7.2 MJ/ ^m2 , and the sheet has a total thickness of 0.30 mm to 0.65 mm.
For example, the back surface of the glass fiber layer constitutes the back surface of the non-combustible wall sheet.

The non-combustible wall sheet of the present invention has a low total heat value, making it suitable as a non-combustible material, and is also resistant to damage, making it suitable as a wall sheet.

1 is a plan view of a non-combustible wall sheet of the present invention. 2 is an enlarged cross-sectional view of the non-combustible wall sheet according to the first embodiment taken along line II-II in FIG. 1. FIG. 6 is an enlarged cross-sectional view of a non-combustible wall sheet according to a second embodiment. FIG. 10 is an enlarged cross-sectional view of the non-combustible wall sheet according to the third embodiment. FIG. 2 is an enlarged cross-sectional view of a main portion of a non-combustible wall sheet having embossed irregularities. A reference diagram showing the manufacturing process of non-flammable wall sheets. A reference diagram showing the manufacturing process of non-flammable wall sheets. FIG. 10 is a reference side view illustrating a test method for a scratch resistance test in the examples.

The present invention will now be described with reference to the accompanying drawings.
In this specification, a numerical range expressed as "lower limit X to upper limit Y" means a range from lower limit X to upper limit Y. When a plurality of such numerical ranges are separately described, any lower limit and any upper limit can be selected to set "any lower limit to any upper limit."
It should also be noted that the dimensions such as thickness and size in each drawing are different from the actual dimensions.

[Outline of non-combustible wall sheet]
FIG. 1 is a plan view of a noncombustible wall sheet 1 according to a first embodiment.
As shown in Figure 1, the non-combustible wall sheet 1 is formed in a long strip shape in a plan view. In this specification, a long strip shape refers to a rectangular shape in which the length in one direction is sufficiently longer than the length in the other direction (the other direction being the direction perpendicular to the one direction), for example, the length in one direction is at least twice, preferably at least four times, the length in the other direction. The long strip non-combustible wall sheet 1 is usually wound into a roll for storage and transportation, and is cut into the desired shape at the construction site for use. However, the non-combustible wall sheet 1 of the present invention is not limited to a long strip sheet, and may be formed into a sheet shape such as a square shape in a plan view (not shown).

The long, strip-shaped non-combustible wall sheet 1 is formed to a predetermined width, for example, 800 mm to 4000 mm, and a predetermined length, for example, 2 m to 300 m. The non-combustible wall sheet 1 formed in a sheet form is usually roughly rectangular in plan view, with its length and width measuring, for example, 100 mm to 4000 mm. However, the sheet-shaped non-combustible wall sheet 1 may also be roughly triangular or roughly hexagonal in plan view, and there are no particular restrictions on its size or shape.

The non-combustible wall sheet 1 is flexible. For example, the degree of flexibility is such that, under standard conditions (23°C, 1 atmosphere, 50% RH), the back surface of the non-combustible wall sheet 1 can be brought into contact with a core material having a diameter of 10 cm and the non-combustible wall sheet 1 can be wrapped around the core material in a roll shape. Similarly, the non-combustible wall sheet 1 can be wrapped around the core material in a roll shape with the front surface of the non-combustible wall sheet 1 in contact with the core material.

The noncombustible wall sheet 1 has certified noncombustible properties. That is, in a heat generation test in which the sheet surface is irradiated with 50 kW/ ^m² of radiant heat from a radiant electric heater, the total heat generation amount for 20 minutes after the start of heating is less than 7.2 MJ/ ^m² (hereinafter, the total heat generation amount for 20 minutes after the start of heating in this heat generation test is simply referred to as the "total heat generation amount"). Furthermore, in the heat generation test, the noncombustible wall sheet 1 of the present invention also satisfies the following conditions: no cracks or holes penetrating to the back surface that are harmful from a fire prevention perspective appear within 20 minutes after the start of heating, and the maximum heat generation rate does not exceed 200 kW/ ^m² for 10 seconds or more within 20 minutes after the start of heating.
The total heat value of the wall sheet is a value measured in accordance with ISO 5560-1.

The noncombustible wall sheet 1 of the present invention comprises a sheet body layer 2 and a design layer 3, with the design layer 3 laminated on the surface of the sheet body layer 2. The sheet body layer 2 is formed to a thickness of more than 0.25 mm and less than 0.50 mm. The thickness of the sheet body layer 2 is preferably 0.3 mm to 0.45 mm, and more preferably 0.35 mm or more and less than 0.45 mm. A noncombustible wall sheet 1 having a sheet body layer 2 of such a thickness has a total calorific value of less than 7.2 MJ/ ^m2 and is resistant to damage. The sheet body layer 2 is formed, for example, from a calender-molded sheet.
The total thickness of the noncombustible wall sheet 1 of the present invention is slightly larger than the thickness of the sheet body layer 2, and is, for example, 0.30 mm to 0.65 mm, preferably 0.35 mm to 0.60 mm, and more preferably 0.45 mm to 0.55 mm.

[Layer structure of non-combustible wall sheet]
FIG. 2 is an enlarged cross-sectional view taken along line II-II in FIG. 1, showing the layer structure of the noncombustible wall sheet 1 according to the first embodiment.
In a preferred layer structure of the present invention, the noncombustible wall sheet 1 has a decorative layer 3 , a sheet body layer 2 , and a glass fiber layer 4 .
The non-combustible wall sheet 1 shown in Figure 2 has the most preferred layer configuration, and has, in order from the surface side, a decorative design layer 3, a sheet body layer 2, and a glass fiber layer 4. In Figure 2, the decorative layer 3 and the sheet body layer 2 are directly bonded. The decorative layer 3 has a desired design visible from the surface side.

The design layer 3 preferably includes, for example, a resin layer 31 and a decorative layer provided on the front and/or back surface of the resin layer 31. If necessary, a transparent protective layer 33 is preferably provided on the outermost surface. The decorative layer is not shown in FIG. 2 (the same applies to FIGS. 3 and 4 ). In this case, the back surface of the resin layer 31 of the design layer 3 is directly bonded to the front surface of the sheet main layer 2. The sheet main layer 2 and the glass fiber layer 4 may be directly bonded together, but as shown in FIG. 2 , the sheet main layer 2 and the glass fiber layer 4 are preferably bonded together via a bonding resin 5. In the illustrated example, the bonding resin 5 is present on the front and back surfaces of the glass fiber layer 4 (the bonding surface side facing the sheet main layer 2 and the side opposite to the bonding surface). However, the bonding resin 5 need only be provided on at least the bonding surface side of the glass fiber layer 4 (the front surface side in the illustrated example). When the bonding resin 5 is not interposed, the glass fiber layer 4 and the sheet main layer 2 are directly bonded together. However, by interposing the bonding resin 5 as described above, the glass fiber layer 4 and the sheet main layer 2 can be strongly bonded together, thereby improving the interlayer adhesive strength between the glass fiber layer 4 and the sheet main layer 2.
It should be noted that although the bonding resin 5 is shown in a uniform layer in Figure 2, in reality the bonding resin 5 is attached around the glass fibers that make up the glass fiber layer 4, and the bonding resin 5 is not interposed between the sheet main layer 2 and the glass fiber layer 4 in a uniform layer as shown (the same applies to Figures 3 to 5).

Figure 3 is an enlarged cross-sectional view showing the layer structure of the non-combustible wall sheet 1 according to the second embodiment, cut at the same location as line II-II in Figure 1, and Figure 4 is an enlarged cross-sectional view showing the layer structure of the non-combustible wall sheet 1 according to the third embodiment, cut at the same location.
The non-combustible wall sheet 1 shown in Figure 3 comprises, from the surface side, a decorative layer 3 and a sheet body layer 2 including a glass fiber layer 4. The glass fiber layer 4 is embedded in the middle of the thickness direction of the sheet body layer 2. In Figure 3, the decorative layer 3 comprises a resin layer 31 and a decorative layer, as in the first embodiment, and preferably further comprises a transparent protective layer 33. Conceptually, the sheet body layer 2 comprises a first sheet layer 21 and a second sheet layer 22 integrated with the glass fiber layer 4 sandwiched therebetween. The glass fiber layer 4 and the sheet body layer 2 (the first sheet layer 21 and the second sheet layer 22) may be directly bonded together. However, to improve interlayer adhesive strength, it is preferable to bond the first sheet layer 21 and the second sheet layer 22 to the glass fiber layer 4 via a bonding resin 5, as shown in Figure 2.
In the layer configuration shown in Figure 3, the glass fiber layer 4 is preferably located below the middle in the thickness direction of the main sheet layer 2. By embedding the glass fiber layer 4 toward the bottom in the thickness direction of the main sheet layer 2 in this way, the distance between the decorative layer 3 and the glass fiber layer 4 becomes relatively large. This makes the main sheet layer 2 stronger and more rigid, making it possible to provide a non-combustible wall sheet 1 that is resistant to damage and has excellent ability to conceal unevenness in the underlying surface.

The noncombustible wall sheet 1 shown in Figure 4 comprises, from the surface side, a decorative design layer 3, a glass fiber layer 4, and a sheet body layer 2. In Figure 4, the decorative layer 3 comprises a resin layer 31 and a decorative layer, as in the first embodiment, and preferably further comprises a transparent protective layer 33. The decorative layer 3 (e.g., the resin layer 31 of the decorative layer 3) and the glass fiber layer 4 may be directly bonded together. However, to improve the interlayer adhesive strength between the decorative layer 3 and the glass fiber layer 4, it is preferable to bond the decorative layer 3 and the glass fiber layer 4 via a bonding resin 5, as shown in Figure 4. Without the bonding resin 5, the decorative layer 3 and the glass fiber layer 4 are directly bonded together. However, as described above, the use of the bonding resin 5 can strengthen the bond between the decorative layer 3 and the glass fiber layer 4. Furthermore, while the sheet body layer 2 and the glass fiber layer 4 may be directly bonded together, it is preferable to bond the sheet body layer 2 and the glass fiber layer 4 via the bonding resin 5.

The surface of the noncombustible wall sheet 1 may be formed with irregularities as required.
5 is an enlarged cross-sectional view of a main part of the non-combustible wall sheet 1 having an uneven surface, showing the decorative layer 32.
The unevenness is formed, for example, by embossing. The arrangement of the recesses 61 and protrusions 62 of the unevenness may be uniform or random. The pattern of the unevenness (pattern in plan view) is not particularly limited, and for example, the unevenness may be formed to form a matte pattern. By forming the unevenness on the surface, the surface glossiness can be reduced, and the unevenness of the underlying surface can be concealed by the non-combustible wall sheet 1. The depth 6H of the recesses 61 is not particularly limited, but from the viewpoint of reducing the surface glossiness and preventing the accumulation of dirt, it is preferably 20 μm to 300 μm, and more preferably 50 μm to 160 μm. However, the depth 6H of the recesses 61 refers to the difference in height between the top surface of the protrusions 62 and the bottom surface of the recesses 61.

<Design layer>
The design layer 3 is a layer that imparts a design to the noncombustible wall sheet 1.
The thickness of the decorative layer 3 is not particularly limited, but is preferably thinner than the sheet body layer 2, for example, 0.05 mm to 0.16 mm, and preferably 0.07 mm to 0.1 mm.
The decorative content (design pattern, etc.) provided on the design layer 3 is not particularly limited.
The design layer 3 is composed of, for example, a resin layer 31 and a decorative layer 32 provided on the front or/back surface of the resin layer 31. The design layer 3 is also composed of a resin layer 31, a decorative layer 32 provided on the front or/back surface of the resin layer 31, and a transparent protective layer 33 provided on the front surface of the resin layer 31 (or on the front surface of the decorative layer 32 if the decorative layer 32 is provided on the front surface of the resin layer 31). When the decorative layer 32 is provided on the back surface of the resin layer 31, a transparent resin layer 31 is used. When the decorative layer 32 is provided only on the front surface of the resin layer 31, the resin layer 31 may be transparent, opaque, or translucent.
Preferably, the design layer 3 consists of a resin layer 31 and a decorative layer 32 provided on the surface of the resin layer 31, or consists of a resin layer 31, a decorative layer 32 provided on the surface of the resin layer 31, and a transparent protective layer 33 provided on the surface of the decorative layer 32. More preferably, the design layer 3 consists of a resin layer 31, a decorative layer 32 provided on the surface of the resin layer 31, and a transparent protective layer 33 provided on the surface of the decorative layer 32.
The resin layer 31 and the protective layer 33 are both non-foamed.

The resin components constituting the resin layer 31 are not particularly limited, and examples include vinyl chloride resins such as polyvinyl chloride (vinyl chloride homopolymer), chlorinated vinyl chloride, and vinyl chloride-vinyl acetate copolymer; polyolefin resins such as polyethylene and polypropylene; styrene resins such as polystyrene; and ester resins such as polyethylene terephthalate. In addition to the resin components, the resin layer 31 may contain various additives, such as colorants such as pigments and stabilizers. In particular, it is preferable for the resin layer 31 to contain titanium oxide. Titanium oxide has excellent hiding power among white pigments. When the noncombustible wall sheet 1 is viewed from its surface, the resin layer 31 can conceal the color of the underlying sheet body layer 2 while highlighting the decorative layer 32. This allows for the provision of a noncombustible wall sheet 1 with a pleasing aesthetic appearance.
Furthermore, the resin layer 31 (or the design layer 3) may contain an inorganic filler such as calcium carbonate, but in order to maintain the strength of the surface side and create a non-combustible wall sheet 1 that is resistant to damage, it is preferable that the resin layer 31 is substantially free of inorganic fillers, and it is even more preferable that the design layer 3 is substantially free of inorganic fillers. The phrase "substantially free of inorganic fillers" means that it is acceptable for inorganic fillers to be accidentally or unavoidably mixed in during the production of the resin layer 31 (or the design layer 3). When the resin layer 31 (or the design layer 3) is substantially free of inorganic fillers, the content of the inorganic filler is 3% by weight or less, preferably 1% by weight or less, when the entire resin layer 31 (or the design layer 3) is taken as 100% by weight.

As will be described later, since the resin layer 31 is firmly bonded to the sheet main layer whose main component resin is vinyl chloride resin or to the bonding resin whose main component resin is urethane resin, it is preferable that the resin layer 31 contains vinyl chloride resin (e.g., polyvinyl chloride or chlorinated vinyl chloride) as the main component resin, and it is more preferable that all of the resin components are vinyl chloride resin.
Here, in this specification, the main component resin (main component) refers to the component (by weight) that is the largest among the resin components (excluding additives) that constitute the layer. The amount of the main component resin is greater than 50% by weight, preferably 70% by weight or more, and more preferably 80% by weight or more, when the total resin components that constitute the layer are taken as 100% by weight. The upper limit of the amount of the main component resin is 100% by weight. When the amount of the main component resin is less than 100% by weight, the resins other than the main component resin contained in the layer are not particularly limited, and known resin components can be used.

In the manufacturing process of the noncombustible wall sheet 1, the resin layer 31 is usually provided as a resin film. By bonding the resin film to the sheet main layer or the like, the resin layer 31 laminated on the sheet main layer 2 or the like can be formed.
From the viewpoint of reducing the total heat generation amount of the noncombustible wall sheet 1, it is preferable that the thickness of the resin layer 31 is as small as possible, but if it is too small, it may become difficult to form the resin layer 31. From this viewpoint, the thickness of the resin layer 31 is preferably 0.04 mm to 0.15 mm, and more preferably 0.07 mm to 0.09 mm.

Examples of the decorative layer 32 provided on the front and/or back surface of the resin layer 31 include a decorative transfer layer and a decorative print layer. The decorative transfer layer is a transfer foil on which a design is displayed, and the decorative layer 32 is formed by attaching the transfer foil to the surface of the resin layer 31. The decorative print layer is a print layer (ink layer) on which a design is printed by a known printing method such as gravure printing on the surface of the resin layer 31.
The thickness of the decorative layer 32 is not particularly limited, and is, for example, 0.1 μm to 10 μm, preferably 1 μm to 7 μm, and more preferably 2 μm to 6 μm.

The surface of the protective layer 33 constitutes the outermost surface of the noncombustible wall sheet 1. The protective layer 33 protects the resin layer 31 including the decorative coating, and prevents dirt from adhering thereto.
The material for forming the protective layer 33 is not particularly limited, and examples thereof include various resins such as acrylic resin, urethane resin, urethane acrylate resin, silicone resin, fluororesin, and isocyanate-based resins; waxes; and varnishes. The resins may be solvent-volatile or ultraviolet-curable. Ultraviolet-curable resins generally can form a protective layer 33 with excellent strength.
Examples of waxes include paraffin wax, acrylic wax, and urethane wax.

The thickness of the protective layer 33 is preferably as small as possible from the viewpoint of reducing the total heat generation of the noncombustible wall sheet 1, but if it is too small, it may not function as a protective layer 33. From this viewpoint, the thickness of the protective layer 33 is preferably 1 μm to 10 μm, and more preferably 2 μm to 7 μm.
Because waxes can be formed to a thin thickness, it is preferable to use waxes as the material for forming the protective layer 33. Furthermore, because they have excellent slipperiness, it is preferable to use acrylic wax, urethane wax, or a mixture of acrylic wax and urethane wax, and it is even more preferable to use a mixture of acrylic wax and urethane wax. The protective layer 33, which has excellent slipperiness, deflects foreign matter when it collides with it, making it less likely to be scratched, and it is also less likely to become soiled.

<Sheet main body layer>
The sheet body layer 2 is formed from a calendered sheet. By using the sheet body layer 2 as a calendered sheet, it is possible to achieve both strength and flexibility as a wall sheet.
As described above, the thickness of the sheet body layer 2 is greater than 0.25 mm and less than 0.50 mm. Because the thickness of the sheet body layer 2 is less than 0.50 mm, a non-combustible wall sheet 1 with a smaller total heat generation can be constructed. On the other hand, because the thickness of the sheet body layer 2 exceeds 0.25 mm, a non-combustible wall sheet 1 with a higher resistance to damage can be constructed. The thickness of the sheet body layer 2 can be appropriately set within the above range. However, from the viewpoint of effectively preventing damage while reducing the total heat generation, the sheet body layer 2 is preferably formed to a thickness of 0.3 mm to 0.45 mm, and more preferably formed to a thickness of 0.35 mm or more and less than 0.45 mm. As shown in FIG. 3 , the thickness of the sheet body layer 2 in which the glass fiber layer 4 is embedded does not include the glass fiber layer 4 (i.e., the thickness of the sheet body layer 2 in which the glass fiber layer 4 is embedded is equivalent to the sum of the thicknesses of the first sheet layer 21 and the second sheet layer 22).

The material for forming the sheet body layer 2 includes a resin component containing chlorinated vinyl chloride, an inorganic filler, a plasticizer, and, if necessary, various additives. Conventional additives can be used, such as flame retardants, stabilizers, moisture absorbents, antioxidants, lubricants, colorants, foaming agents, and antifungal agents. The sheet body layer 2 may be foamed, but is typically non-foamed. By using a resin component containing chlorinated vinyl chloride, a sheet body layer 2 with excellent strength and high damage prevention effect can be formed with a relatively small amount of resin.
The resin component constituting the sheet main layer 2 need only contain chlorinated vinyl chloride, and may be, for example, a mixture of chlorinated vinyl chloride and a resin other than vinyl chloride-based resin (e.g., polyolefin-based resin, styrene-based resin, etc.), but is preferably a vinyl chloride-based resin containing chlorinated vinyl chloride.
Examples of the vinyl chloride resin include polyvinyl chloride, chlorinated vinyl chloride, and copolymers of vinyl chloride monomers and other monomers (for example, vinyl chloride-vinyl acetate copolymers), as exemplified for the resin layer 31 above.

Here, polyvinyl chloride refers to a homopolymer of vinyl chloride monomer. Polyvinyl chloride produced by emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, or the like can be used. In the present invention, polyvinyl chloride having an average degree of polymerization of about 500 to 2000, preferably about 700 to 1800, can be used.
Chlorinated vinyl chloride refers to a chlorinated product of polyvinyl chloride. In terms of the manufacturing process, chlorinated vinyl chloride refers to a resin obtained by chlorinating polyvinyl chloride after obtaining polyvinyl chloride by one of the various methods described above. Known types of chlorinated vinyl chloride include thermally chlorinated vinyl chloride and photo-chlorinated vinyl chloride, and either may be used. Thermally chlorinated vinyl chloride is chlorinated vinyl chloride by heating, and photo-chlorinated vinyl chloride is chlorinated vinyl chloride by ultraviolet light.
The chlorine content of chlorinated vinyl chloride is 57 to 80% by weight, preferably 60 to 70% by weight. By using chlorinated vinyl chloride having a chlorine content within this range, the total calorific value can be reduced without reducing the strength of the resin.

The resin component constituting the main sheet layer 2 is preferably a vinyl chloride resin containing chlorinated vinyl chloride as a main component. In this case, the resin component constituting the main sheet layer 2 may be chlorinated vinyl chloride alone, a mixture of chlorinated vinyl chloride and polyvinyl chloride, or a mixture of chlorinated vinyl chloride, polyvinyl chloride, and other resins.
When the resin component constituting the main sheet layer 2 is a mixture of chlorinated vinyl chloride and polyvinyl chloride, the amount of chlorinated vinyl chloride is, for example, 20% by weight or more, preferably 30% by weight or more, more preferably 40% by weight or more, and even more preferably 60% by weight or more, when the entire resin component (mixture) is taken as 100% by weight. The upper limit of the amount of chlorinated vinyl chloride in the mixture is less than 100% by weight. When the resin component constituting the main sheet layer 2 is composed solely of chlorinated vinyl chloride, the amount is 100% by weight. Among these, the resin component constituting the main sheet layer 2 is preferably composed solely of chlorinated vinyl chloride, or a mixture of chlorinated vinyl chloride and polyvinyl chloride, with chlorinated vinyl chloride as the main resin component, since the total calorific value is smaller than that of the same amount of polyvinyl chloride. A mixture composed solely of chlorinated vinyl chloride is more preferred, and a mixture composed solely of chlorinated vinyl chloride is even more preferred.

Examples of the inorganic filler include calcium carbonate, calcium borate, calcium oxide, barium carbonate, magnesium hydroxide, aluminum hydroxide, silica, clay, talc, and mica.
The inorganic filler is a solid substance under standard conditions, and its volume average particle size (50% diameter) is, for example, 0.05 μm to 20 μm, preferably 1 μm to 10 μm, and more preferably 2 μm to 6 μm.
It is preferable to incorporate a large amount of inorganic filler, as this allows for the formation of a sheet main body layer 2 that has a small total calorific value and is relatively inexpensive. On the other hand, if the amount of inorganic filler is too large, the proportion of the resin component becomes relatively small, resulting in a decrease in the strength of the sheet main body layer 2. From this perspective, the inorganic filler is preferably contained in an amount of 40 to 80% by weight, and more preferably 60 to 70% by weight, when the entire sheet main body layer 2 is taken as 100% by weight.
The inorganic filler may be one type alone or a combination of two or more types from the above examples, but calcium borate is particularly preferred. Calcium borate dehydrates when heated, so the sheet body layer 2 containing calcium borate has a slower heat generation rate and a lower maximum heat generation rate.
When the inorganic filler contains calcium borate, the amount of calcium borate is not particularly limited, but from the viewpoint of the above-mentioned effects, when the total inorganic filler is taken as 100% by weight, it is preferably contained in an amount of more than 0 to 80% by weight or less, more preferably 10% to 50% by weight, and even more preferably 20% to 40% by weight. If the calcium borate content is within the above range, the sheet main layer 2 can be produced without deterioration in processability.

Inorganic fillers containing calcium borate consist of calcium borate alone, or calcium borate in combination with other inorganic fillers. When calcium borate is used in combination, examples of inorganic fillers used in combination with calcium borate include calcium carbonate or silica, or a combination of calcium carbonate and silica.

Examples of the plasticizer include phosphate esters, adipate esters, dioctyl phthalate (DOP), dibutyl phthalate (DBP), butyl octyl phthalate (BOP), dioctyl isophthalate (DOIP), diisononyl phthalate (DINP), di-2-ethylhexyl terephthalate (DOTP), etc. It is preferable to use a plasticizer that is liquid under standard conditions.
The amount of plasticizer is not particularly limited. From the viewpoint of achieving good plasticization while reducing the total heat generation amount of the sheet main body layer 2, the plasticizer is preferably contained in an amount of 5 to 35% by weight, and more preferably 10 to 20% by weight, when the entire sheet main body layer 2 is taken as 100% by weight.

In particular, it is preferable to use at least one of a phosphate ester and an adipic acid ester as the plasticizer, since this allows the formation of a sheet main body layer 2 with a small total calorific value. In this case, the plasticizer consists of only a phosphate ester, only an adipic acid ester, or a mixture of a phosphate ester and an adipic acid ester. An adipic acid ester and/or a phosphate ester is suitable when the sheet main body layer 2 is produced by a calendaring method.
Adipic acid ester is relatively inexpensive, has better plasticizing efficiency than phosphate ester, and can maintain the flexibility of the sheet main layer 2 even in a low-temperature environment. For this reason, the plasticizer preferably contains an adipic acid ester, and more preferably contains a relatively large amount of the adipic acid ester. For example, the adipic acid ester is contained in an amount of 50 to 100% by weight when the total weight of the plasticizer is taken as 100% by weight.
In particular, it is preferable to use only an adipic acid ester or a mixture of a phosphate ester and an adipic acid ester as the plasticizer. Since a phosphate ester has a lower combustion calorie than an adipic acid ester, it is more preferable to use a combination of a phosphate ester and an adipic acid ester as the plasticizer. When a phosphate ester and an adipic acid ester are used in combination, it is preferable that the ratio of the adipic acid ester is high, and for example, the weight ratio of the phosphate ester to the adipic acid ester is preferably 30:70 to 49:51.

<Glass fiber layer>
The glass fiber layer 4 is made of a woven or nonwoven fabric containing glass fibers.
It is preferable to use a woven glass fiber fabric for the glass fiber layer 4 because it can prevent harmful deformation during combustion, has flexibility, and has excellent tear strength and tensile strength. Examples of the weave of the woven fabric include plain weave, satin weave, twill weave, basket weave, and rib weave, and among these, plain weave, basket weave, and rib weave are preferred.
The glass fiber may be a monofilament or a multifilament. When a woven fabric is used as the glass fiber layer 4, the glass fibers (threads constituting the woven fabric) constituting the woven fabric are preferably multifilament. When a nonwoven fabric is used as the glass fiber layer 4, the glass fibers constituting the nonwoven fabric are preferably multifilament.
A glass multifilament is a single thread formed by bundling a plurality of glass monofilaments. The number of monofilaments in the multifilament is not particularly limited, but is, for example, 5 to 3,000, and preferably 100 to 400. The multifilament may be a twisted thread. The number of twists is not particularly limited, but is, for example, 1 turn/25 mm to 4 turns/25 mm.
From the viewpoint of flexibility, tear strength, tensile strength and cuttability of the non-combustible wall sheet 1, the count of the multifilament is preferably 10 tex to 100 tex, more preferably 20 tex to 50 tex.

The thread density of the woven fabric is not particularly limited. From the perspective of ensuring the flexibility of the non-combustible wall sheet 1 and creating a non-combustible wall sheet 1 that can conceal unevenness in the underlying surface, it is preferable that the warp and weft thread densities of the woven fabric are each independently between 50 threads/25mm and 80 threads/25mm, with a total density of 100 threads/25mm and 160 threads/25mm. It is even more preferable that the warp and weft thread densities of the woven fabric are each independently between 50 threads/25mm and 80 threads/25mm, with a total density of 110 threads/25mm and 130 threads/25mm. The total density is the sum of the warp and weft thread densities.

<Bonding resin>
The bonding resin 5 contains, as a main component resin, a resin that has excellent adhesive properties to both the sheet body layer 2 and the glass fiber layer 4 .
Examples of the bonding resin 5 include urethane resins, acrylic resins, and olefin resins such as polyethylene and polypropylene. The bonding resin 5 preferably contains a urethane resin as a main component resin because it has excellent adhesive properties to both glass fiber and vinyl chloride resin.
The amount of bonding resin 5 is not particularly limited, but if it is too much, the amount of heat generated by bonding resin 5 increases, and if it is too little, the improvement in interlayer strength due to bonding resin 5 decreases. From this perspective, the amount of bonding resin 5 is preferably 4 g/m ² to 10 g/m ² , and more preferably 5 g/m ² to 7 g/m ² .

[Production method of non-combustible wall sheet]
The noncombustible wall sheet 1 of the present invention can be produced, for example, by the following procedure: However, the noncombustible wall sheet 1 of the present invention is not limited to those produced by the following production method.
The noncombustible wall sheet of the present invention comprises a molding step of a sheet body layer, a laminating step of laminating a glass fiber layer on the sheet body layer, and a laminating step of laminating a design layer on the sheet body layer.
Figures 6 and 7 show an example of a manufacturing apparatus 9 for manufacturing the non-combustible wall sheet 1 having the layer structure shown in Figure 2. In Figures 6 and 7, the rotation direction of each roll is indicated by an arrow, and the sheet conveyance direction is indicated by a hollow arrow.

Referring to Figure 6, the material 2A for forming the main sheet layer is supplied between the calender rolls 91, 91. As described above, the material 2A for forming the main sheet layer is prepared by blending predetermined amounts of resin components, such as vinyl chloride resin, inorganic filler, plasticizer, and optional additives, and mixing them in a mixing machine (not shown). Whether the main resin component is polyvinyl chloride or chlorinated vinyl chloride, the resin temperature during mixing is preferably in the range of 150°C to 200°C.

The forming material 2A is formed into a sheet by passing it through multiple calender rolls 91. The temperature of the calender rolls 91 is equal to or higher than the melting temperature of the resin component. Whether the main component resin is polyvinyl chloride or chlorinated polyvinyl chloride, it is preferable to set the temperature of the calender rolls 91 in the range of 100°C to 200°C.

The calendered sheet obtained by passing through the calender rolls 91 is the main sheet layer 2. A glass fiber layer 4A is laminated on the back surface of this main sheet layer.
As described above, the glass fiber layer 4A is made of, for example, a woven fabric with glass fibers (glass multifilaments) as warp and weft threads. A bonding resin is applied to at least the surface (the surface to be bonded to the sheet main layer 2) of the glass fiber layer 4A. The bonding resin is applied by a method such as coating, spraying, or dipping. For example, a glass fiber layer having bonding resin on both the front and back surfaces can be obtained by dipping (immersing) the glass woven fabric (glass fiber layer) in the bonding resin. Alternatively, a glass fiber layer having bonding resin mainly on the surface can be obtained by coating or spraying the bonding resin on the front side of the glass woven fabric (glass fiber layer). Applying the bonding resin to the glass fiber layer by dipping or the like can prevent fraying of the glass fibers and increase the strength of the glass fibers. Furthermore, even if the glass fiber layer is made of a woven fabric, the bonding resin can firmly bond the glass fiber layer to the sheet main layer.

The surface of the glass woven fabric 4A, at least the surface of which is coated with a bonding resin, is brought into contact with the back surface of the sheet body layer 2 emerging from the calender roll 91, and the two are passed through nip rolls 92 and pressed together to obtain a composite sheet 1A consisting of the sheet body layer and the glass fiber layer in that order from the surface side. Because the two can be bonded together by residual heat, there is no need to heat the glass fiber layer and the sheet body layer when laminating them. However, heating may be performed at this time as well, if necessary.
The obtained composite sheet 1A is temporarily wound up on a winding roll 93.
The wound composite sheet 1A is subjected to the process shown in Fig. 7. However, the composite sheet 1A may be subjected to the process shown in Fig. 7 as it is without being wound into a roll.

7, the composite sheet 1A is unwound and heated in a heating device 95 such as an oven. The composite sheet 1A is heated in the heating device 95 so that the surface temperature of the composite sheet 1A reaches, for example, 100°C to 150°C. A decorative resin film 31A is laminated on the surface of the composite sheet 1A. The decorative resin film 31A becomes a decorative resin layer by being laminated on the sheet body layer 2. The decorative resin film 31A can be, for example, a vinyl chloride resin film printed with a decorative print layer.
A resin film 31A is brought into contact with the surface of the composite sheet 1A softened by heating, and both are passed through a nip roll 96 to press the composite sheet 1A, which consists of a design layer/sheet body layer/glass fiber layer in that order from the surface side.

A protective layer forming material 33A is applied to the surface of this composite sheet 1A (e.g., the surface of the decorative printing layer) and then solidified. As described above, waxes or the like can be used as the protective layer forming material 33A. The method for applying the protective layer forming material 33A is not particularly limited, and any conventionally known method can be used. However, gravure printing is preferred because it can form a relatively thin and substantially uniform layer. For example, the protective layer can be formed by applying the protective layer forming material 33A using a gravure roll 97 and then drying the material in a drying device 98. If the protective layer forming material 33A is an ultraviolet-curable resin, the material is cured using an ultraviolet irradiation device (not shown).
In this way, a non-combustible wall sheet 1 is obtained, which is composed of the decorative layer 3, the sheet body layer 2 and the glass fiber layer 4, as shown in FIG.
If necessary, an embossing roll 99 is applied to the surface of the non-combustible wall sheet 1 to form irregularities, and then the non-combustible wall sheet 1 is wound up on a take-up roll 93 .

The present invention will be further described in detail below with reference to examples and comparative examples. However, the present invention is not limited to the following examples.

<Materials for forming the sheet main layer>
Polyvinyl chloride: Product name "ZEST 800Y" manufactured by Shin-Daiichi Vinyl Corporation.
- Chlorinated polyvinyl chloride: "Heat-resistant Kanevinyl H438" manufactured by Kaneka Corporation.
- Phosphate ester: "Leophos 35" manufactured by Ajinomoto Fine-Techno Co., Ltd.
Adipic acid ester: "BXA-N", a product name manufactured by Daihachi Chemical Industry Co., Ltd.
・Dioctyl phthalate (DOP)
"DOP" manufactured by J Plus Co., Ltd.
Calcium carbonate: Product name "Escalon #200" manufactured by Sankyo Flour Milling Co., Ltd.
- Calcium borate: Product name "Colemanite UBP" manufactured by Kinseimatec Co., Ltd.
- Titanium oxide: Product name "Tipake CR60-2" manufactured by Ishihara Sangyo Kaisha, Ltd.
- Silica: Product name "NIPSIL AQ" manufactured by Tosoh Silica Corporation.
- Stabilizer: ADECA Corporation's product name "ADEKA STAB NPS-309".

<Design layer>
As the design layer, a printed vinyl chloride resin film having a thickness of 80 μm (trade name "PVC decorative sheet" manufactured by Toppan Printing Co., Ltd.) was used.
<Glass fiber layer>
The glass fiber layer was a resin-coated glass woven fabric (trade name "Sealed Glass Cloth" manufactured by Unitika Ltd.) with a thickness of approximately 0.10 mm, which was a plain-woven fabric of glass fibers (multifilament) impregnated with a bonding resin (urethane resin). The warp threads of this glass woven fabric were 22.5 tex/thread, the weft threads were 22.5 tex/thread, and the total density was 120 threads/25 mm. The weight of the glass woven fabric was 105 g/ ^m² , and the weight of the resin-coated glass woven fabric was 113 g/ ^m² .

[Example 1]
The materials were mixed and pelletized according to the formulation shown in Table 1 (the amount of each material is expressed in parts by weight), and the pellets were then melted at 140°C. The melt was passed through a calender roll at 150°C to perform calendering processing, thereby producing a sheet body layer (calendered sheet) with a thickness of approximately 0.30 mm.
The sheet body layer was layered on the surface of the glass fiber layer (resin-coated glass woven fabric), and the design layer (printed vinyl chloride resin film) was then layered on the surface of the sheet body layer. The entire laminate was then heated to 150°C using a preheater while being pressed at 30 kgf/ ^cm² to integrate the layers. In this way, a non-flammable wall sheet consisting of, from the surface side, the design layer/sheet body layer/glass fiber layer was produced. The thickness of this wall sheet was approximately 0.47 mm.

[Examples 2 to 5, Comparative Examples 1 to 4]
A non-combustible wall sheet was produced in the same manner as in Example 1, except that the sheet body layer was formed to have the thickness shown in Table 2.

<Total heat generation>
The theoretical total heat generation values of the wall sheets of Examples 1 to 5 and Comparative Examples 1 to 4 were calculated.
The theoretical total calorific value of the wall sheets in each example was calculated from the content of resin components and plasticizers, excluding inorganic components (inorganic fillers, glass fiber layers, etc.), and the calorific value of these components. The results are shown in Table 2.
The theoretical value was used as the total heat generation value of the wall sheets in the examples and comparative examples because, based on experience, it is known that the measured value of the total heat generation value and the theoretical value are almost similar, and because actually measuring the total heat generation value involves a great deal of cost and time.
However, the total heat value of the wall sheet described in the claims of this patent refers to an actual measured value.

For the wall sheet of Example 3, the total heat generation amount was actually measured.
Specifically, the wall sheet of Example 3 was cut into a square shape with a side measuring 99 mm±1 mm in plan view, and this was used as a test specimen. This test specimen was heated at a heating intensity of 50 kW/ ^m2 using a cone calorimeter in accordance with ISO 5660-1, and the total heat generation amount for 20 minutes after the start of heating was measured.
As a result, the measured value of the total calorific value in Example 3 was roughly the same as the theoretical value.

<Scratch resistance test>
The scratch resistance of the wall sheets of each of the Examples and Comparative Examples was tested as follows, and the results are shown in Table 2.
Evaluation of Gouge Damage A 12.5 mm thick gypsum board (trade name: Tiger Board GB-R) manufactured by Yoshino Gypsum Co., Ltd. was prepared as a place where the wall sheet was to be laid.
The wall sheets of each Example and Comparative Example were each cut to a length x width of 150 mm x 200 mm to obtain a sample piece. The sample piece was attached to the surface of a gypsum board using an acrylic resin adhesive. The gypsum board with the attached sample piece was fixed in a state tilted at 60 degrees relative to the horizontal. A 400 g iron weight with an arc-shaped tip (see Figure 8 for the shape and dimensions of the weight) was allowed to fall naturally onto the surface of the sample piece (wall sheet) from a drop height of 750 mm, as shown in Figure 8, and the surface of the sample piece (wall sheet) was then visually observed.
In the gouge damage column of Table 2, "○" indicates that weight marks were observed but the sheet was not damaged, "△" indicates that the sheet was slightly damaged, and "×" indicates that the sheet was severely damaged.
As in the evaluation of gouge damage, a sample piece (wall sheet) attached to a gypsum board was prepared and placed parallel to a horizontal surface (fixed horizontally). A 1.5 kg egg-shaped iron weight was allowed to fall naturally onto the surface of the sample piece (wall sheet) from a height of 2000 mm, and the surface of the sample piece (wall sheet) was then visually observed.
In the column for impact of heavy objects in Table 2, "○" indicates that no cracks occurred in the sheet, "△" indicates that cracks occurred in part of the sheet, and "×" indicates that cracks occurred throughout the entire sheet.

From Examples 1 to 5 and Comparative Examples 1 to 4, it can be seen that wall sheets having a sheet body layer thickness of more than 0.25 mm have good scratch resistance. Also, it can be seen that the wall sheet of Comparative Example 4 having a sheet body layer thickness of 0.50 mm or more has a total calorific value of more than 7.2 MJ/ ^m² .

[Examples 6 to 9, Comparative Example 5]
A sheet body layer having a thickness of approximately 0.40 mm was prepared in the same manner as in Example 4, except that the materials for forming the sheet body layer were changed to the composition shown in Table 3 (the amount of each material is expressed in parts by weight), and this sheet body layer was used to prepare a non-flammable wall sheet having a total thickness of approximately 0.57 mm.
The theoretical total heat generation values of the wall sheets obtained in Examples 6 to 9 and Comparative Example 5 were calculated in the same manner as above. The results are shown in Table 3.

The wall sheets of Examples 6 to 9 had a total calorific value of less than 7.2 MJ/m ² , and the wall sheet of Comparative Example 5 had a total calorific value of 7.2 MJ/m ² .
A comparison of Examples 4 and 6 reveals that the more chlorinated vinyl chloride is contained, the smaller the total calorific value of the wall sheet obtained.
A comparison of Examples 7 and 8 reveals that phosphate esters are more effective at reducing the total calorific value than adipic acid esters.

REFERENCE SIGNS LIST 1 Non-combustible wall sheet 2 Sheet body layer 3 Design layer 31 Resin layer 32 Decorative layer 33 Protective layer 4 Glass fiber layer 5 Bonding resin

Claims (2)

The sheet has a main sheet layer having a thickness of more than 0.25 mm and less than 0.50 mm, a design layer laminated on the surface of the main sheet layer, and a glass fiber layer laminated on the back side of the main sheet layer,
the sheet main body layer contains a resin component containing chlorinated vinyl chloride , an inorganic filler, and a plasticizer,
The inorganic filler is contained in an amount of 40% by weight to 80% by weight when the entire sheet main body layer is taken as 100% by weight,
the plasticizer comprises a phosphate ester, an adipate ester, dioctyl phthalate, dibutyl phthalate, butyl octyl phthalate, dioctyl isophthalate, diisononyl phthalate, or di-2-ethylhexyl terephthalate;
In a heat generation test in which radiant heat of 50 kW/ ^m² is irradiated onto the sheet surface from a radiant electric heater, the total heat generation amount for 20 minutes after heating starts is less than 7.2 MJ/ ^m² ,
A non-combustible wall sheet having a total thickness of 0.30 mm to 0.65 mm. The non-combustible wall sheet according to claim 1, wherein the back surface of the glass fiber layer forms the back surface of the non-combustible wall sheet.