JP2015110290A - Transparent nonflammable sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent nonflammable sheet which has high transparency and high mechanical strength and whose warpage due to heat is effectively suppressed.SOLUTION: The transparent nonflammable sheet includes a plurality of glass fiber fabrics and a cured resin composition layer with which the plurality of glass fiber fabrics are impregnated. The cured resin composition layer is formed of a cured product of a resin composition containing a curable resin. The glass fiber fabrics are respectively arranged on at least both surface sides of the cured resin composition layer so that the center in the thickness direction of each of the glass fiber fabrics is positioned closer to the surface side than the center in the thickness direction of the cured resin composition layer. The transparent nonflammable sheet has a total light transmittance of 80% or more and a haze of 30% or less.

Description

  The present invention relates to a transparent noncombustible sheet. Furthermore, the present invention relates to a smoke-proof hanging wall, a smoke-proof shutter, a partition wall, a smoke-proof curtain, and a touch panel using the transparent non-combustible sheet.

  The Building Standards Law and the Building Standards Law Enforcement Ordinance stipulate that smoke-exhaust facilities should be installed so that smoke, toxic gases, etc. generated in the event of a building fire can be prevented and evacuation and fire fighting activities can be carried out smoothly. Yes. Therefore, in buildings such as office buildings and commercial facilities, smoke barriers are often installed as smoke exhausting equipment and smoke shielding equipment. In addition, for example, a sheet shutter that moves up and down during use may be installed at an entrance / exit of a factory, a warehouse, or the like. Such a sheet shutter may be composed of a transparent resin sheet and a framework so that the other side can be seen even when the sheet shutter is lowered (see, for example, Patent Document 1). By imparting smoke resistance to such a sheet shutter, it can be expected to suppress the flow of smoke and the like in the event of a fire. Therefore, it is conceivable to use a sheet shutter as disclosed in Patent Document 1 as a smoke-proof shutter.

  In addition, smoke barriers are usually used for the purpose of temporarily blocking the flow of smoke and toxic gases from the fire to the corridors and upper floors to ensure the time required for evacuation. It is attached to the ceiling of the object. For this reason, transparent plate glass, a transparent resin composite of glass fiber and resin, or the like is used as the smoke proof wall so that the visual field is not hindered by the smoke proof wall and the aesthetic appearance is not impaired. The transparent resin composite of glass fiber and resin has the advantage that it is less likely to break compared to transparent plate glass. For example, Patent Document 2 discloses a smoke barrier wall made of a transparent noncombustible sheet including a glass fiber fabric and a cured resin layer.

Japanese Patent Laid-Open No. 06-173557 JP 2005-319746 A

  For example, since the sheet shutter disclosed in Patent Document 1 is made of transparent vinyl chloride, it can exhibit excellent transparency, but it is not only inferior incombustibility but also has a very high mechanical strength. Has the problem of low. On the other hand, in the transparent noncombustible sheet as disclosed in Patent Document 2, since a glass fiber fabric is sandwiched between a pair of cured resin layers, it is compared with the sheet shutter disclosed in Patent Document 1. And has the advantage of excellent mechanical strength.

  In recent years, smoke barriers, smoke shutters, partition walls, smoke curtains, touch panels, and the like have been required to further increase mechanical strength in addition to high smoke resistance and transparency. Then, this inventor examined the method which raises mechanical strength further, maintaining high smoke resistance and high transparency in the transparent noncombustible sheet as disclosed in Patent Document 2. In such a transparent incombustible sheet, in order to further increase the mechanical strength, it is conceivable to increase the thickness of the glass fiber fabric sandwiched between the pair of cured resin layers or increase the content ratio. However, in the transparent incombustible sheet, when the thickness of the glass fiber fabric is increased or the content ratio is increased, the mechanical strength is increased, but the transparency of the transparent incombustible sheet is lowered. The inventor further studied a method for further increasing the mechanical strength while maintaining high transparency in the transparent noncombustible sheet. As a result, in the configuration in which the glass fiber fabric is sandwiched between a pair of cured resin layers as disclosed in Patent Document 2, it is difficult to further increase the mechanical strength while maintaining high transparency. It came to the conclusion that it is necessary to adopt a new configuration different from that of Document 2.

  Under such circumstances, the main object of the present invention is to provide a transparent non-combustible sheet having high transparency and high mechanical strength. Furthermore, another object of the present invention is to provide a smoke-proof hanging wall, smoke-proof shutter, partition wall, smoke-proof curtain, and touch panel using the transparent non-combustible sheet. In the present invention, “high transparency” means that the total light transmittance is 80% or more and the haze is 30% or less.

  The present inventor has intensively studied to solve the above problems. As a result, it has been found that by arranging a plurality of glass fiber fabrics at specific positions in the transparent noncombustible sheet, the mechanical strength can be further increased while maintaining high transparency. More specifically, in a transparent noncombustible sheet comprising a glass fiber fabric and a cured resin composition layer impregnated in the glass fiber fabric, the central portion in the thickness direction of the glass fiber fabric is the cured resin composition layer. The mechanical strength of the transparent noncombustible sheet is further increased by disposing glass fiber fabrics on at least both surface sides of the cured resin composition layer so as to be located on the surface side of the central portion in the thickness direction. It was found that a transparent incombustible sheet having high transparency such that the total light transmittance of the transparent incombustible sheet is 80% or more and the haze of the transparent incombustible sheet is 30% or less can be obtained. Furthermore, this inventor discovered that the curvature with respect to heat | fever can be suppressed very effectively in such a transparent incombustible sheet. The present invention has been completed by further studies based on these findings.

That is, this invention provides the invention of the aspect hung up below.
Item 1. A transparent noncombustible sheet comprising a plurality of glass fiber fabrics and a cured resin composition layer impregnated in the plurality of glass fiber fabrics,
The cured resin composition layer is formed of a cured product of a resin composition containing a curable resin,
The center part in the thickness direction of the glass fiber fabric is located on the surface side of the center part in the thickness direction of the cured resin composition layer, and at least on both surface sides of the cured resin composition layer, A glass fiber fabric is arranged,
The total light transmittance of the transparent noncombustible sheet is 80% or more,
The transparent incombustible sheet whose haze of the said transparent incombustible sheet is 30% or less.
Item 2. Item 2. The transparent noncombustible sheet according to Item 1, wherein the curable resin contains at least one selected from the group consisting of vinyl ester resins, unsaturated polyester resins, and fluorene acrylate resins.
Item 3. Item 3. The transparent noncombustible sheet according to Item 1 or 2, wherein the resin composition contains 40 to 80% by mass of the curable resin.
Item 4. Item 3. The transparent noncombustible sheet according to any one of Items 1 to 3, wherein the resin composition contains a styrene monomer.
Item 5. Item 5. The transparent noncombustible sheet according to Item 4, wherein the resin composition contains 60 to 80% by mass of the curable resin and 10 to 40% by mass of the styrene monomer.
Item 6. Item 6. The transparent noncombustible sheet according to any one of Items 1 to 5, wherein the resin composition is photocurable.
Item 7. Item 7. The transparent noncombustible sheet according to any one of Items 1 to 6, wherein a total ratio of the glass fiber fabric in a total amount of the glass fiber fabric and the cured resin composition layer is 20 to 50% by mass. Transparent incombustible sheet.
Item 8. Item 8. The transparent noncombustible sheet according to any one of Items 1 to 7, further comprising a film layer on the cured resin composition layer.
Item 9. Item 9. The transparent noncombustible sheet according to Item 8, further comprising a network layer composed of a glass fiber network between the cured resin composition layer and the film layer.
Item 10. Item 10. The transparent noncombustible sheet according to any one of Items 1 to 9, wherein the thickness is 40 to 400 µm.
Item 11. Item 11. A smoke barrier wall comprising the transparent incombustible sheet according to any one of Items 1 to 10.
Item 12. Item 11. A smoke-proof shutter comprising the transparent incombustible sheet according to any one of Items 1 to 10.
Item 13. Item 11. A partition wall comprising the transparent noncombustible sheet according to any one of Items 1 to 10.
Item 14. Item 11. A smokeproof curtain comprising the transparent noncombustible sheet according to any one of Items 1 to 10.
Item 15. Item 10. A touch panel comprising the transparent noncombustible sheet according to any one of items 1 to 10.

  According to the transparent non-combustible sheet of the present invention, it is possible to provide a transparent non-combustible sheet having high transparency and high mechanical strength and further effectively suppressing warpage against heat. The transparent non-combustible sheet of the present invention not only has high transparency, but also high mechanical strength, and also effectively suppresses warping against heat. Therefore, the smoke proof wall, smoke proof shutter, partition wall, It can be suitably used as a smoke curtain, a touch panel or the like.

1 is a schematic cross-sectional view of a transparent noncombustible sheet of the present invention. 1 is a schematic cross-sectional view of a transparent noncombustible sheet of the present invention. 1 is a schematic cross-sectional view of a transparent noncombustible sheet of the present invention. 1 is a schematic cross-sectional view of a transparent noncombustible sheet of the present invention.

  The transparent incombustible sheet of the present invention is a transparent incombustible sheet comprising a plurality of glass fiber fabrics and a cured resin composition layer impregnated in the plurality of glass fiber fabrics, and the cured resin composition layer is cured. It is formed by the hardened | cured material of the resin composition containing a resin, and it hardens | cures so that the center part in the thickness direction of a glass fiber fabric may be located in the surface side rather than the center part in the thickness direction of a cured resin composition layer Glass fiber fabrics are disposed on at least both surface sides of the resin composition layer, the total light transmittance of the transparent incombustible sheet is 80% or more, and the haze of the transparent incombustible sheet is 30% or less. It is characterized by.

  For example, as shown in FIG. 1, the transparent noncombustible sheet 1 of the present invention has a laminated structure including a plurality of glass fiber fabrics 2 and a cured resin composition layer 3 impregnated in the plurality of glass fiber fabrics 2. . In the transparent noncombustible sheet 1 of the present invention, the two glass fiber fabrics 2 are arranged so as to be positioned on both surfaces 31 and 32 side of the cured resin composition layer 3, respectively. More specifically, as will be described later, the center portion N in the thickness direction of the two glass fiber fabrics 2 is positioned closer to the surfaces 31 and 32 than the center portion M in the thickness direction of the cured resin composition layer 3, respectively. Thus, the glass fiber fabric 2 is arranged. Moreover, the two glass fiber fabrics 2 located on the both surfaces 31 and 32 side of the cured resin composition layer 3 are arranged so as to be separated from each other. In the transparent noncombustible sheet 1 of the present invention, it is sufficient that at least the two glass fiber cloths 2 are arranged, and three or more glass fiber cloths 2 may be arranged. In the transparent noncombustible sheet 1 of the present invention, each glass fiber fabric 2 constitutes a layer in the cured resin composition layer 3.

  For example, as shown in FIG. 1, the two glass fiber fabrics 2 may be positioned inside the surfaces 31 and 32 of the cured resin composition layer 3, respectively, for example, as shown in FIG. 2. Alternatively, it may be located on the surface 31, 32 portion of the cured resin composition layer 3. That is, in the transparent incombustible sheet 1, the cured resin composition layer 3 may be formed on the surface of at least one glass fiber fabric 2, or the surface of at least one glass fiber fabric 2 may have a surface. It may coincide with the surfaces 31 and 32 of the cured resin composition layer 3. However, in the transparent noncombustible sheet 1 of the present invention, it is preferable that the cured resin composition layer 3 is formed on the surface of at least one of the glass fiber fabrics 2 from the viewpoint of further increasing the transparency. For example, as FIG. 1 shows, it is more preferable that the cured resin composition layer 3 is formed on the surface of any glass fiber fabric 2 layer. Furthermore, in the transparent noncombustible sheet 1 of the present invention, from the viewpoint of more effectively suppressing warping due to heat, for example, as shown in FIG. 1, two sheets located on both surface sides of the curable resin layer 3 are used. It is particularly preferable that the glass fiber fabric 2 is disposed at a substantially symmetrical position with reference to the length direction of the central portion of the curable resin layer 3. That is, it is preferable that the distance between the center portion N of each of the two glass fiber fabrics 2 located on both surface sides of the curable resin layer 3 and the center portion M of the curable resin layer 3 is substantially the same.

  The cured resin composition layer 3 fills the gaps between the plurality of glass fibers constituting the glass fiber fabric 2, and one surface side portion 31 and the other surface side portion 32 of the cured resin composition layer 3 Communicates through the gap portion.

  In the transparent noncombustible sheet 1 of the present invention, on the cured resin composition layer 3, for example, as shown in FIGS. 3 and 4, the noncombustible property of the transparent noncombustible sheet 1 is increased or the mechanical strength (hardness) The film layer 4 may be laminated as necessary for the purpose of increasing the thickness). Further, as shown in FIG. 4, it is necessary between the cured resin composition layer 3 and the film layer 4 for the purpose of further increasing the mechanical strength (hardness) of the transparent noncombustible sheet 1. Depending on the case, the network layer 5 made of glass fiber may be laminated. The film layer 4 and the net body layer 5 may be laminated on one side of the cured resin composition layer 3, respectively, or may be laminated on both sides as shown in FIGS. Hereinafter, the composition of each layer constituting the transparent noncombustible sheet 1 of the present invention will be described in detail.

  In the transparent noncombustible sheet 1 of the present invention, the cured resin composition layer 3 is impregnated in a glass fiber fabric 2 described later, and is formed of a cured product of a resin composition containing a curable resin. Specifically, the cured resin composition layer 3 is formed of a cured product obtained by curing the resin composition by applying energy such as light and heat to the resin composition containing the curable resin.

  The curable resin is not particularly limited as long as it can approximate the cured resin composition layer 3 and the refractive index of the glass fiber fabric 2 described later. Examples of preferable curable resins include vinyl ester resins, urethane acrylate resins, fluorene acrylate resins, and unsaturated polyester resins. For example, when E glass is used as the glass material of the glass fiber constituting the glass fiber fabric 2, vinyl ester resin, unsaturated polyester resin, and fluorene acrylate resin are preferable from the viewpoint of adjusting the refractive index. A curable resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  Although it does not restrict | limit especially as a ratio of curable resin in the resin composition which forms the cured resin composition layer 3, From a viewpoint of exhibiting suppression of the curvature with respect to high transparency, high mechanical strength, and heat, 40-80. About mass% is preferable and about 60-80 mass% is more preferable. In addition, when a resin composition contains resin other than curable resin, it is preferable that the ratio of resin other than curable resin in a resin composition is 20 mass% or less.

  The resin composition forming the cured resin composition layer 3 preferably contains a styrene monomer from the viewpoint of adjusting the refractive index. By including a styrene monomer, it becomes easy to adjust the viscosity of the resin composition. The ratio of the styrene monomer in the resin composition is not particularly limited, and for example, 0 to 40% by mass, preferably about 10 to 40% by mass, and more preferably about 15 to 30% by mass.

  Moreover, from a viewpoint of adjusting the refractive index, a monomer component other than the styrene monomer may be included, and two or more curable resins having different refractive indexes may be combined. Further, the refractive index can be adjusted by a refractive index adjusting agent such as metal oxide fine particles.

  Moreover, the resin composition which forms the cured resin composition layer 3 may contain bifunctional (meth) acrylate as needed. A bifunctional (meth) acrylate has two (meth) acrylate groups in the molecule, and when energy such as light such as ultraviolet rays or heat is applied, the curable resin is crosslinked by the (meth) acrylate groups. In the present invention, “(meth) acrylate” means “acrylate” or “methacrylate”.

  In the present invention, when the cured resin composition layer 3 is formed of a cured product of a resin composition containing a curable resin and a bifunctional (meth) acrylate, the glass fiber fabric 2 described later is impregnated. In addition, it is possible to provide a transparent non-combustible sheet that is not only highly transparent but also suppressed in blurring and color bleeding. In the present invention, “blurred” means that the scenery looks blurred when looking through the transparent incombustible sheet, and “color blur” means that the light of the fluorescent lamp passes through the transparent incombustible sheet. When you see the color, such as red or blue appears to blur.

  Examples of the bifunctional (meth) acrylate include di (meth) acrylate of alkylene diol having 1 to 6 carbon atoms. Thereby, the transparency of the transparent noncombustible sheet 1 of the present invention can be increased, and blurring and color bleeding can be more effectively suppressed. The details of this reason are not necessarily clear, but in di (meth) acrylates of alkylene diols having 1 to 6 carbon atoms, the molecular chain of the alkylene diol component in the molecule is short, so the glass fiber and the cured resin composition This is probably because the curable resin can be cross-linked more densely at the interface.

  Furthermore, the bifunctional (meth) acrylate is particularly preferably a di (meth) acrylate of an alkylene diol having 1 to 6 carbon atoms and the carbon chain of the alkylene diol having a branched structure. Thereby, the transparency of the transparent noncombustible sheet 1 of the present invention can be increased, and blurring and color bleeding can be more effectively suppressed. Although the details of the reason are not necessarily clear, the glass fiber and the cured resin composition described later are combined with the fact that the molecular chain of the alkylene diol component is shorter and the reactivity with the curable resin is further increased. It is considered that this is because the high continuity of the interface with the substrate is particularly effectively maintained.

  From the same viewpoint, the molecular weight of the bifunctional (meth) acrylate is preferably 250 or less. Moreover, 150 or more are preferable and, as for the molecular weight of bifunctional (meth) acrylate, 200 or more are more preferable.

  As specific examples of the bifunctional (meth) acrylate, preferably 1,3-butylene glycol diacrylate (molecular weight 198), 1,4-butanediol diacrylate (molecular weight 198), 1,5-pentanediol diacrylate (molecular weight) 212), 1,6-hexanediol diacrylate (molecular weight 226), diethylene glycol diacrylate (molecular weight 214), dipropylene glycol diacrylate (molecular weight 242), neopentyl glycol diacrylate (molecular weight 212), 1,3-butylene glycol Dimethacrylate (molecular weight 226), 1,4-butanediol dimethacrylate (molecular weight 226), 1,5-pentanediol dimethacrylate (molecular weight 240), diethylene glycol dimethacrylate (molecular weight 242), O neopentyl glycol dimethacrylate (molecular weight 240), and the like. Among these, as the carbon chain of the alkylene diol has a branched structure, 1,3-butylene glycol diacrylate, dipropylene glycol diacrylate, neopentyl glycol diacrylate, 1,3-butylene glycol dimethacrylate, Neopentyl glycol dimethacrylate and the like are preferable. Bifunctional (meth) acrylate may be used individually by 1 type, and may be used in combination of 2 or more types.

  The bifunctional (meth) acrylate functions as a curing agent that cures the curable resin by applying energy such as light and heat in the presence of the curable resin. The bifunctional (meth) acrylate is preferably a photocuring agent that cures the curable resin when irradiated with light such as ultraviolet rays. In this case, the resin composition forming the cured resin composition layer 3 is photocurable.

  The ratio of the bifunctional (meth) acrylate in the resin composition is not particularly limited and may be, for example, about 0 to 40% by mass, and is preferably about 10 to 20% by mass from the viewpoint of blur suppression. In the transparent noncombustible sheet of the present invention, even if the resin composition forming the cured resin composition layer 3 does not contain a bifunctional (meth) acrylate, it has high transparency and high mechanical strength. Furthermore, the curvature with respect to heat can be suppressed effectively. For this reason, in this invention, it is not necessary to contain bifunctional (meth) acrylate in the said resin composition.

  The resin composition forming the cured resin composition layer 3 may further contain additives such as a flame retardant, an ultraviolet absorber, a filler, and an antistatic agent. Examples of the flame retardant include aluminum hydroxide, magnesium hydroxide, trichloroethyl phosphate, triallyl phosphate, ammonium polyphosphate, and phosphate ester. Examples of the ultraviolet absorber include benzotriazole. Examples of the filler include calcium carbonate, silica, and talc. Examples of the antistatic agent include a surfactant. These additives may be used individually by 1 type, and may be used in combination of 2 or more types.

  In the present invention, when the transparent non-combustible sheet 1 is used as a smoke proof wall or a smoke proof sheet, it is cured with a glass fiber fabric 2 to be described later in order to prevent the visual field from being obstructed or detracting from aesthetics. The refractive index of the resin composition 3 is set so as to approximate. From such a viewpoint, the refractive index of the cured resin composition 3 is preferably about 1.45 to 1.65, more preferably about 1.50 to 1.60.

  In the transparent noncombustible sheet 1 of the present invention, the glass fiber fabric 2 is composed of a plurality of glass fibers. In the glass fiber fabric 2, the plurality of glass fibers are entangled with each other to form a single fabric. Examples of the glass fiber fabric 2 include a glass fiber fabric (glass cloth) composed of a plurality of warps and a plurality of wefts. The woven structure of the glass fiber fabric is not particularly limited, and examples thereof include plain weave, satin weave, twill weave, oblique weave, and woven weave. The woven density of the glass fiber woven fabric is not particularly limited. For example, if the woven density is 60 pieces / 25 mm or more, the glass fiber woven fabric 2 can be used even when the cured resin composition of the transparent incombustible sheet 1 is burned. Is not preferable because large through-holes are not formed and excellent incombustibility is maintained.

  It does not restrict | limit especially as a glass material of the glass fiber which comprises the glass fiber fabric 2, For example, a well-known glass material can be used. Examples of the glass material include alkali-free glass (E glass), acid-resistant alkali-containing glass (C glass), high-strength and high-modulus glass (S glass, T glass, etc.), alkali-resistant glass (AR glass), NE glass etc. are mentioned, Preferably alkali-free glass (E glass) with high versatility is mentioned. The glass fibers constituting the glass fiber fabric 2 may be made of one kind of glass material, or may be a combination of two or more kinds of glass fibers made of different glass materials.

  The count of the glass fibers constituting the glass fiber fabric 2 is not limited to a specific one as long as the glass fiber fabric 2 can be formed. The count of the glass fiber is preferably 20 tex or less from the viewpoint of increasing the woven density. One type of glass fiber count may be used alone, or two or more types may be combined. The tex count of glass fiber corresponds to the number of grams per 1000 m.

  The glass fiber constituting the glass fiber fabric 2 is preferably a glass yarn in which a plurality of single fibers, which are long glass fibers, are twisted together. The number of single fibers in the glass yarn is preferably about 30 to 400, more preferably about 40 to 120. Moreover, the diameter of the single fiber in the glass yarn is preferably about 3.0 to 6.0 μm from the viewpoint of further enhancing mechanical strength while effectively suppressing warpage due to heat while imparting high transparency. About 3.0-5.0 micrometers is more preferable. The glass yarn count is preferably 3 to 30 tex, more preferably 3 to 12 tex, more preferably 3 to 5 tex from the viewpoint of further enhancing mechanical strength and effectively suppressing warpage due to heat while imparting high transparency. Is more preferable.

  From the viewpoint of enhancing the adhesion between the glass fiber fabric 2 and the cured resin composition layer 3 and enhancing the durability of the transparent noncombustible sheet 1 of the present invention, the surface of the glass fiber constituting the glass fiber fabric 2 is silane. The surface is preferably treated with a coupling agent.

In the transparent incombustible sheet 1, as the total ratio of the plurality of glass fiber fabrics 2 in the total amount of the glass fiber fabric 2 and the cured resin composition layer 3, the mechanical strength is improved while maintaining high transparency, From the viewpoint of suppressing warpage due to heat, it is preferably about 15 to 50% by mass, more preferably about 20 to 35% by mass, and particularly preferably about 20 to 28% by mass. In the transparent incombustible sheet 1 of the present invention, since the two glass fiber fabrics 2 have the above specific arrangement, high transparency and high mechanical strength can be obtained even when the total ratio is set to 20 to 28% by mass, for example. Furthermore, the weight of the transparent incombustible sheet 1 can be reduced while effectively suppressing the warpage against heat. From the same viewpoint, the mass (g / m ² ) of one piece of the glass fiber fabric ² is preferably 10 to 120 g / m ² , more preferably 10 to 60 g / m ² , and more preferably 10 to 40 g / m ^2. Further preferred.

Furthermore, when the total ratio of the glass fiber fabric 2 in the transparent noncombustible sheet 1 is about 20 to 28% by mass and the mass of one piece of the glass fiber fabric 2 is about 10 to 40 g / m ² , it is highly transparent. And high mechanical strength, suppression of warpage due to heat, and weight reduction effect can be further enhanced.

  As described above, the transparent noncombustible sheet 1 of the present invention includes a plurality of glass fiber fabrics 2. For example, as shown in FIG. 1, the cured resin composition is such that the central portion N in the thickness direction of the glass fiber fabric 2 is located on the surface side of the central portion M in the thickness direction of the cured resin composition layer 3. Glass fiber fabrics 2 are disposed on at least both surface sides of the physical layer 3 (31 side and 32 side in FIG. 1). That is, in the transparent noncombustible sheet 1 of the present invention, at least two glass fiber fabrics 2 are respectively disposed on the surface side of the cured resin composition layer 3, and the two glass fiber fabrics 2 are mutually connected. They are spaced apart.

  In the transparent noncombustible sheet 1 of the present invention, the two glass fiber fabrics 2 are arranged so as to be positioned on at least both surface sides (31 side and 32 side in FIG. 1) of the cured resin composition layer 3, respectively. Thus, for example, compared with a transparent non-combustible sheet in which a glass fiber fabric is disposed only in the central portion of the cured resin composition layer disclosed in Patent Document 2 described above, without impairing high transparency. Further, the mechanical strength (hardness) can be further increased, and warping due to heat can be effectively suppressed.

More specifically, in the transparent noncombustible sheet 1 of the present invention, the shortest distance L ₁ from the surface of the cured resin composition layer 3 to the center N of the glass fiber fabric 2 and the thickness of the cured resin composition layer 3. It is more preferable that L ₀ is included on each of both surface sides of the cured resin composition layer 3 so as to satisfy the relationship of the following formula (I).
0% <L ₁ / L ₀ × 100 <30% (I)

Further, the above L ₁ and the L _0, particularly preferably satisfies the relationship of _{10 (%) <L 1 /} L 0 × 100 <20 (%).

  The difference in refractive index between the glass fiber fabric 2 and the cured resin composition layer 3 is preferably 0.05 or less, more preferably 0.02 or less. The refractive index of the glass fiber fabric 2 is preferably about 1.45 to 1.65, more preferably about 1.50 to 1.60.

In addition, the measurement of the refractive index of the said glass fiber fabric 2 is performed according to B method of JISK7142: 2008. Specifically, with respect to the glass fibers constituting the glass fiber fabric 2, methylene iodide (n _D ²³ 1.747), butyl phthalate (n _D ²³ 1.491) and dimethyl carbonate (n _D ²³ 1) are used as the immersion liquid. 366), NAG-2T manufactured by Atago Co., Ltd. as an Abbe refractometer, and sodium D line with a wavelength of 589 nm as a light source, measured at a temperature of 23 ° C., and the average value of five tests is refracted The value of rate. Moreover, the measurement of the refractive index of the cured resin composition 3 is performed according to B method of JISK7142: 2008. Specifically, the cured cured resin composition is pulverized and methylene iodide (n _D ²³ 1.747), butyl phthalate (n _D ²³ 1.491) and dimethyl carbonate (n _D ²³ ) are used as the immersion liquid. 1.366), using a small measurement microscope STM5-311 (Olympus, observation magnification: 400 times) as a microscope, using sodium D-line with a wavelength of 589 nm as a light source, and measuring at a temperature of 23 ° C. The average value of the times is taken as the refractive index value.

  From the viewpoint of further improving mechanical strength while effectively suppressing warping due to heat while maintaining high transparency of the transparent noncombustible sheet, the thickness of one piece of the glass fiber fabric 2 is preferably 10 to 10. About 100 micrometers, More preferably, it is about 10-55 micrometers, More preferably, about 10-35 micrometers is mentioned. From the same viewpoint, when the thickness of one glass fiber fabric 2 is 10 to 35 μm, the glass volume ratio calculated by the following formula (II) is 38 to 50 for the total of the two glass fiber fabrics 2. % Is particularly preferred. The glass fiber fabric 2 having a glass fiber fabric 2 having a thickness of 10 to 35 μm and a glass volume ratio of 38 to 50% can be obtained, for example, by subjecting the glass fiber to a fiber opening treatment. In the following formula (II), the mass A of the glass fiber fabric is the sum of the masses of the two glass fiber fabrics, and the thickness C of the glass fiber fabric is the sum of the thicknesses of the two glass fiber fabrics. .

Glass volume (%) = (A / (B × C)) × 100 (II)
A: Mass of glass fiber fabric (g / m ² )
B: Specific gravity (g / m ³ ) of the glass material constituting the glass fiber fabric
C: thickness of glass fiber fabric (m)

  For example, as shown in FIG. 3, the transparent non-combustible sheet 1 of the present invention is formed on the cured resin composition layer 3 as necessary for the purpose of enhancing non-combustibility or increasing mechanical strength. A film layer 4 may be further included. The resin (resin film) constituting the film layer 4 is not particularly limited, and preferably includes a flame-retardant synthetic resin such as a vinyl chloride resin. In addition, resin which comprises the film layer 4 may have a flame retardance by resin itself, and may have a flame retardance by mix | blending a flame retardant etc. In the present invention, by providing the film layer 4, the weather resistance of the transparent noncombustible sheet 1 can be increased, or damage due to contact with other objects can be prevented. Can also function. The transparent incombustible sheet 1 of the present invention preferably has film layers 4 on both sides.

  When the transparent incombustible sheet 1 of the present invention has the film layer 4, the thickness of the film layer 4 is not particularly limited, and for example, about 50 to 200 μm, preferably about 80 to 150 μm.

  For example, as shown in FIG. 4, the transparent non-combustible sheet 1 of the present invention has a cured resin composition layer 3 and a layer as necessary for the purpose of enhancing non-combustibility or mechanical strength. Between the film layer 4, you may have further the net body layer 5 which consists of glass fiber net bodies. The glass fiber network constituting the network layer 5 is not particularly limited, and examples thereof include the same glass fiber network as the glass fiber exemplified in the glass fiber fabric 2. The shape and structure of the glass fiber network are not particularly limited, and examples of the glass fiber network include a glass fiber orthogonal laminated net in which a weft is sandwiched between two warps and fixed with a resin. In the network layer 5, by setting the opening width between the glass fibers to preferably 3 to 20 mm, high transparency of the transparent incombustible sheet 1 can be secured, and further, through the opening between the glass fibers. Can be well-lighted, and the strength of the transparent incombustible sheet 1 can be increased. The transparent incombustible sheet 1 of the present invention preferably has a net layer 5 on both sides from the viewpoint of enhancing incombustibility and increasing mechanical strength.

  When the transparent incombustible sheet 1 of the present invention has the network layer 5, the thickness of the network layer 5 is not particularly limited, and may be about 50 to 300 μm, preferably about 100 to 200 μm, for example.

  As thickness of the transparent incombustible sheet 1 of this invention, Preferably about 40-400 micrometers is mentioned.

  In the present invention, when the transparent non-combustible sheet 1 is used as a smoke-proof hanging wall, a smoke-proof sheet, a partition wall, a smoke-proof curtain (for example, one used in a factory, etc.), a touch panel, etc., the visual field is obstructed. Or has high transparency in order to suppress the loss of aesthetics. From the viewpoint of ensuring high transparency, the total light transmittance of the transparent noncombustible sheet 1 of the present invention is 80% or more, preferably 85% or more. Moreover, the haze of the transparent noncombustible sheet 1 of the present invention is 30% or less, preferably 20% or less, and more preferably 10% or less. The total light transmittance and haze of the transparent noncombustible sheet 1 are values obtained by measurement according to JIS K7375 2008 “Plastics—How to obtain total light transmittance and total light reflectance”, respectively.

  In the transparent incombustible sheet 1 of the present invention, the difference between the Abbe number of the cured resin composition and the Abbe number of the glass fiber is preferably 40 or less, and more preferably 30 or less. In order to make Abbe number 40 or less, it becomes easy by making the difference of the refractive index of glass fiber fabric 2 and cured resin composition layer 3 0.02 or less. In addition, the Abbe number of a cured resin composition and glass fiber is measured as follows.

(Abbe number of cured resin composition)
A sheet of a cured resin composition that does not contain glass fiber fabrics is prepared with the same thickness under the same conditions as when glass fiber fabrics are contained, the test piece is 8 mm wide and 20 mm long, and the surface is well polished, and JIS K According to the 7142A method, NAR-2T manufactured by Atago Co., Ltd. as an Abbe refractometer, diiodomethane as a contact liquid, sodium D-line having a wavelength of 589 nm as a light source, a measurement temperature of 23 ° C., and a refractive index at a wavelength of 589 nm are measured. . Subsequently, the dispersion value is measured and calculated using the light source as natural light, and the Abbe number is calculated according to the following formula (III).
Abbe number = (refractive index-1 at a wavelength of 589 nm) / dispersion value (III)

(Abbe number of glass fiber)
Using a glass material constituting the glass fiber, a glass plate having a width of 8 mm, a length of 20 mm, and a thickness of 5 mm is prepared, and the surface is well polished. As an Abbe refractometer, manufactured by Atago Co., Ltd. according to the JIS K 7142A method. Using NAR-2T, diiodomethane as a contact liquid, sodium D-line having a wavelength of 589 nm as a light source, the measurement temperature is 23 ° C., and the refractive index at a wavelength of 589 nm is measured. Subsequently, the dispersion value is measured and calculated using the light source as natural light, and the Abbe number is calculated according to the above formula (III).

The transparent non-combustible sheet 1 of the present invention has high transparency, high mechanical strength, and high non-combustibility, and is effectively inhibited from impeding the visual field or impairing aesthetics. It can be suitably used as a smoke proof wall, smoke proof sheet, partition wall, smoke proof curtain, touch panel and the like. The nonflammability of the transparent nonflammable sheet 1 of the present invention is that the surface of the transparent nonflammable sheet 1 is irradiated with radiant heat of 50 kW / m ^{2 with} a radiant electric heater, and the total calorific value for 20 minutes after the start of heating is 8 MJ. / m ² or less, which means non-flammability that does not exceed 200 kW / m ² with the maximum exotherm rate continuing for 10 seconds or more in 20 minutes after the start of heating.

  It does not restrict | limit especially as a manufacturing method of the transparent noncombustible sheet 1 of this invention, For example, the following manufacturing methods are mentioned. First, one glass fiber fabric 2 is impregnated with the above resin composition constituting the cured resin composition layer 3 so that the glass fiber fabric 2 is in a desired arrangement, and cured, to make one glass fiber fabric. A sheet containing 2 is prepared. At this time, a film of polyethylene terephthalate or the like coated with the above resin composition is prepared, and the film is pressure-bonded from both sides of one glass fiber fabric 2 to be resin composition from both sides of one glass fiber fabric 2 It is also possible to obtain a sheet in which the cured resin composition layer 3 is impregnated into one glass fiber fabric 2 by peeling the film after impregnating the resin composition and curing the resin composition. Next, in the same manner, another sheet in which the cured resin composition layer 3 is impregnated with one glass fiber fabric 2 is produced. Of the two sheets obtained, the above resin composition is applied to one sheet, the other sheet is laminated from above, and the resin composition is cured, so that at least two glass fiber fabrics are obtained. A transparent noncombustible sheet located on the surface side is obtained.

  As another manufacturing method, two films of polyethylene terephthalate or the like coated with the above resin composition are prepared, and the films are pressure-bonded from the respective surfaces of the two glass fiber fabrics 2, respectively. There is a method in which the resin composition is poured from between the two glass fiber fabrics 2 so that the arrangement of the two glass fiber fabrics 2 becomes a desired arrangement while the resin composition is impregnated, and the resin composition is cured. Also by such a manufacturing method, a transparent noncombustible sheet in which two glass fiber fabrics are arranged on both surface sides is obtained.

When the resin composition is cured by applying thermal energy, the heating temperature is not particularly limited, and can be, for example, about 50 to 200 ° C. Moreover, when hardening a resin composition by provision of light energy, light is irradiated and hardened | cured to a resin composition. As conditions for light irradiation, for example, the integrated light quantity can be set to 100 to 500 mJ / cm ² .

  When the transparent noncombustible sheet 1 of the present invention has the film layer 4, after placing the above resin film constituting the film layer 4 on the cured resin composition layer 3 obtained above, a press machine or the like is used. The film layer 4 can be formed on the cured resin composition layer 3 by being heated and pressurized. Moreover, when it has further the network body layer 6 which consists of a glass fiber network between the cured resin composition layer 3 and the film layer 4, on the cured resin composition layer 3, for example from urethane type resin etc. After applying the adhesive which becomes, after arrange | positioning said glass fiber network which comprises the network layer 6 from this, and also arrange | positioning said resin film which comprises the film layer 4 on a glass fiber network The network layer 5 and the film layer 4 can be formed on the cured resin composition layer 3 by heating and pressing using a press or the like.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

As the glass fiber fabric, commercially available glass fiber fabrics (glass material: E glass, specific gravity 2.54 g / cm ³ ) shown in Table 1 were cut into 200 mm × 200 mm and used. In Table 1, “E03R SK”, “E06C SK”, “E10T”, and “E18A” are trade names of E glass fiber fabrics manufactured by Unitika Ltd. The E glass fiber fabric is subjected to a heat treatment for removing organic substances and a surface treatment with a silane coupling agent. The glass material used in Examples 1 to 3 had a glass volume ratio of 39.4%.

  As the resin composition impregnated into the above glass fiber fabric, a vinyl ester resin (manufactured by Nippon Yupica Co., Ltd.), an unsaturated polyester resin (manufactured by Nippon Yupica Co., Ltd.), and fluorene acrylate resin are prepared so as to have the composition shown in Table 1. (Osaka Gas Chemical Co., Ltd.), styrene monomer (Nippon Iupika Co., Ltd.), bifunctional (meth) acrylate, and a photopolymerization initiator mixture were used. In addition, as a bifunctional (meth) acrylate which is a hardening | curing agent, the NPGDA (Neopentyl glycol diacrylate, the molecular weight 212, (made by Nippon Iupika Co., Ltd.)) of Table 1 was used. Moreover, the quantity of the photoinitiator was 2 mass parts with respect to a total of 100 mass parts of vinyl ester resin, unsaturated polyester resin, or fluorene acrylate resin, a styrene monomer, and bifunctional (meth) acrylate.

<Examples 1-4>
First, on a PET film having a thickness of 0.05 mm, a resin composition in an amount of 40% by mass of the amount (g / m ² ) described in Table 1 was applied. Next, the glass fiber fabric of the amount (g / m ² ) shown in Table 1 was placed on the resin composition and allowed to stand for 1 minute to impregnate the above resin in the gaps of the glass fiber fabric. At this time, the glass fiber fabric was pushed into the lower part, and the position of the glass fiber fabric was adjusted to the position shown in Table 1. Next, a PET film having a thickness of 0.05 mm was placed from above, and pressure was applied from above with a roller. Thereafter, together with the above PET film, the resin composition is irradiated with light (light irradiation condition: accumulated light quantity 200 mJ / cm ² ) to cure the resin composition, form a cured resin composition layer, and one glass fiber fabric. A containing sheet (sheet 1) was prepared. Similarly, another sheet was prepared (sheet 2). Next, of the obtained two sheets, the PET film is removed from one sheet 1, and an amount of 20% by mass of the amount (g / m ² ) described in Table 1 is formed on the sheet 1. A transparent noncombustible sheet having the thickness shown in Table 1 was obtained by applying the resin composition, laminating the other sheet 2 thereon, and curing the resin composition between both sheets. In the obtained transparent noncombustible sheet, the gap between the glass fibers of the glass fiber fabric is impregnated with a cured resin composition layer (cured product of the resin composition), and on both surfaces of the glass fiber fabric layer. A cured resin composition layer was formed, and two glass fiber fabrics were located on both surface sides of the sheet.

Two glass fiber fabrics were arranged at respective positions on both surface sides of the cured resin composition layer calculated according to the above-described formula (I). For example, in Examples 1 to 4 in Table 1, two glass fiber fabrics are arranged on both surface sides of the cured resin composition layer, and in each glass fiber fabric, from the surface of the cured resin composition layer. It shows that the shortest distance L ₁ to the center N of the glass fiber fabric and the thickness L ₀ of the cured resin composition layer are both L ₁ / L ₀ × 100 = 18%.

<Comparative Examples 1 and 3>
First, a resin composition having an amount (g / m ² ) shown in Table 1 was applied on a PET film having a thickness of 0.05 mm. Next, the glass fiber fabric of the amount (g / m ² ) shown in Table 1 was placed on the resin composition and allowed to stand for 1 minute to impregnate the above resin in the gaps of the glass fiber fabric. Next, a PET film having a thickness of 0.05 mm was placed from above, and pressure was applied from above with a roller. Then, the resin composition was cured by irradiating the resin composition together with the above PET film (light irradiation condition: integrated light quantity 200 mJ / cm ² ) to form a cured resin composition layer. Next, the PET film was removed to obtain a transparent noncombustible sheet having the thickness described in Table 1. In the obtained transparent noncombustible sheet, the gap between the glass fibers of the glass fiber fabric is impregnated with a cured resin composition layer (cured product of the resin composition), and on both surfaces of the glass fiber fabric layer. A cured resin composition layer was formed.

<Comparative Example 2>
First, on a PET film having a thickness of 0.05 mm, a resin composition having an amount of 50% by mass (g / m ² ) described in Table 1 was applied. Next, one glass fiber fabric having an amount (g / m ² ) shown in Table 1 was placed on the resin composition so as to be positioned on the outermost surface of the resin composition. Next, a PET film having a thickness of 0.05 mm is placed from above, and the resin composition is cured by irradiating the resin composition together with the PET film (light irradiation condition: integrated light quantity 200 mJ / cm ² ). A layer was formed, and a sheet (sheet 1) containing one glass fiber fabric on the outermost surface of the resin composition layer was prepared.

Separately, a resin composition having an amount of 40% by mass of the amount (g / m ² ) shown in Table 1 was applied on a PET film having a thickness of 0.05 mm. Next, one glass fiber fabric of the amount (g / m ² ) shown in Table 1 was placed on the resin composition and allowed to stand for 1 minute to impregnate the above resin in the gaps of the glass fiber fabric. . At this time, the glass fiber fabric was pushed into the lower part, and the position of the glass fiber fabric was adjusted to the position shown in Table 1 (18%). Next, a PET film having a thickness of 0.05 mm was placed from above, and pressure was applied from above with a roller. Thereafter, together with the above PET film, the resin composition is irradiated with light (light irradiation condition: accumulated light quantity 200 mJ / cm ² ) to cure the resin composition, form a cured resin composition layer, and one glass fiber fabric. A containing sheet (sheet 2) was prepared.

Next, a resin composition in an amount of 10% by mass of the amount (g / m ² ) described in Table 1 is applied to the surface of the sheet 1 on which the glass fiber fabric is located on the outermost surface, and the other sheet is formed thereon. 2 was laminated by removing the PET film, and the resin composition between both sheets was cured to obtain a transparent incombustible sheet having the thickness shown in Table 1. In the obtained transparent noncombustible sheet, the gap between the glass fibers of the glass fiber fabric is impregnated with a cured resin composition layer (cured product of the resin composition), and on both surfaces of the glass fiber fabric layer. A cured resin composition layer was formed, and two glass fiber fabrics were located on both surface sides of the sheet.

In Comparative Example 2, the shortest distance L ₁ to the central portion N of one glass fiber fabric and the thickness L ₀ of the cured resin composition layer are L ₁ / L ₀ × 100 = 18%, It shows that the shortest distance L ₁ to the center portion N of the other glass fiber fabric and the thickness L ₀ of the cured resin composition layer are L ₁ / L ₀ × 100 = 50%. That is, in the comparative example 2, the center part N of one glass fiber fabric and the center part M of the cured resin composition layer coincide.

  In Examples and Comparative Examples, the woven density of the glass fiber fabric was measured and calculated according to JIS R 3420 2013 7.9. Moreover, the thickness of the glass fiber fabric was measured and calculated according to JIS R 3420 2013 7.10.1A method. The mass of the glass fiber fabric was measured and calculated according to JIS R 3420 2013 7.2. The refractive indexes of the cured resin composition and the glass fiber fabric were measured and calculated by the above method. The following evaluation was performed after leaving the room indoors for one week after the production of the transparent incombustible sheet.

(Position of glass fiber fabric)
Each transparent incombustible sheet obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was observed with a scanning electron microscope, and the position (%) of the glass fiber fabric was calculated according to the above-described formula (I). The results are shown in Table 1.

(Hardness of transparent noncombustible sheet)
Sensory evaluation was performed about hardness by five panelists. External force was applied to the transparent non-combustible sheet by hand, and the following five grades were evaluated in order from the one felt to be hard. Four or more points were accepted. The results are shown in Table 1.
5: The mechanical strength was sufficiently high and there was no problem in practical use.
4 ... Mechanical strength was high and practically no problem.
3 ... The mechanical strength was slightly high, and it was at a level where there was no practical problem.
2 ... Mechanical strength was slightly low, which was a slightly problematic level for practical use.
1 ... Mechanical strength was low, which was a problem level for practical use.

(Warp of transparent noncombustible sheet)
The transparent incombustible sheet was heat-treated at 100 ° C. for 3 minutes with a dryer, then warped and evaluated according to the following criteria. The results are shown in Table 1.
◎ ・ ・ ・ No warpage occurred.
○: Slight warping occurred, but at a level that was not a problem for practical use.
Δ: Slightly large warp, practically somewhat problematic level.
X: The warpage was very large and there was a problem in practical use.
The results are shown in Table 1.

(Evaluation of nonflammability)
The surface of each transparent non-combustible sheet obtained in Examples 1 to 3 and Comparative Examples 1 and ² was irradiated with 50 kw / m ² of radiant heat with a radiant electric heater, and the total calorific value for 20 minutes after the start of heating and heating The time when the calorific value exceeded 200 kw / m ² in 20 minutes after the start was measured. Excellent nonflammability when the total calorific value for 20 minutes after the start of heating is 8 MJ / m ² or less and the maximum exotherm rate does not exceed 200 kW / m ² for 20 minutes or more after the start of heating for 10 seconds or more (◎ ) And evaluation.

(Evaluation of blur)
Place a thousand yen bill on the desk, place a transparent incombustible sheet approximately 50 cm above the thousand yen bill, and observe the thousand yen bill through the transparent incombustible sheet from 10 cm above the transparent incombustible sheet The evaluation was based on whether or not the characters of “1000 yen”, “Bank of Japan” and the serial number can be read clearly. The evaluation criteria are as follows. From the viewpoint of practicality, in the present invention, 2 or more was considered acceptable. The results are shown in Table 1.
5 ... "Thousand yen", "Bank of Japan note", and the letters of serial numbers were all clearly readable.
4. Only the letters “1000 yen” and “Bank of Japan” were clearly read.
3… Only “1000 yen” could be read clearly.
2… Only “1000 yen” characters can be read, but not clearly.
1 ... None of the characters could be read and could not be read clearly.

(Evaluation of color blur)
Each transparent incombustible sheet was seen through a fluorescent lamp, and an evaluation was made based on whether or not the color blur around the fluorescent lamp was noticeable. The evaluation criteria are as follows. From the viewpoint of practicality, in the present invention, 3 or more was considered acceptable. The results are shown in Table 1.
5 ... The color blur around the fluorescent lamp was hardly noticeable.
4 ... The color blur around the fluorescent light looks faint, but it was not noticeable.
3 ... The color around fluorescent lamps was blurred and was noticeable to some extent.
2 ... The color blur around the fluorescent lamp was noticeable.
1 ... The color blur around the fluorescent lamp was very noticeable and the transparency was impaired.

(Total light transmittance and haze)
The total light transmittance and haze of each transparent incombustible sheet were measured according to JIS K7375 2008 “Plastics—How to obtain total light transmittance and total light reflectance”.

  As shown in Table 1, both of the cured resin composition layers were formed such that the central portion in the thickness direction of the glass fiber fabric was positioned on the surface side of the central portion in the thickness direction of the cured resin composition layer. In the transparent noncombustible sheets of Examples 1 to 4 in which glass fiber fabrics are arranged on the surface side, not only have high transparency, but also have very high mechanical strength (hardness), It was clarified that there was no warping due to heat and it could be suitably used as a smoke barrier. In particular, in the sheets of Examples 1 to 3, the total ratio of the glass fiber cloth in the total amount of the glass fiber cloth and the cured resin composition layer in the transparent incombustible sheet was in the range of 20 to 28% by mass. Therefore, high transparency and high mechanical strength were imparted, and the warpage due to heat was effectively suppressed, and at the same time, the weight could be reduced.

  On the other hand, the transparent noncombustible sheet of Comparative Example 1 in which only one glass fiber fabric is disposed at the center of the cured resin composition layer has high transparency, but the transparent noncombustible of Examples 1 to 4 The sheet was inferior in terms of mechanical strength (hardness) and warpage due to heat as compared with the adhesive sheet. Also, two glass fiber fabrics are used, one glass fiber fabric is disposed so as to be located on the surface side of the central portion in the thickness direction of the cured resin composition layer, and the other glass fiber fabric is used as the cured resin composition. Although the transparent noncombustible sheet of Comparative Example 2 disposed at the center in the thickness direction of the layer also has high transparency, it has mechanical strength (hardness) compared to the transparent noncombustible sheets of Examples 1 to 4. ) And warpage due to heat. Furthermore, in the transparent noncombustible sheet of Comparative Example 3 in which only one glass fiber fabric is arranged at the center of the cured resin composition layer, the thickness of the glass fiber fabric is increased to increase the mechanical strength. ) And warpage due to heat were raised to a level where there was no practical problem, but the transparency was remarkably lowered and the haze was increased.

DESCRIPTION OF SYMBOLS 1 ... Transparent incombustible sheet 2 ... Glass fiber fabric 3 ... Cured resin composition layer 31, 32 ... Surface of cured resin composition layer 4 ... Film layer 5 ... Network layer

Claims (15)

A transparent noncombustible sheet comprising a plurality of glass fiber fabrics and a cured resin composition layer impregnated in the plurality of glass fiber fabrics,
The cured resin composition layer is formed of a cured product of a resin composition containing a curable resin,
The center part in the thickness direction of the glass fiber fabric is located on the surface side of the center part in the thickness direction of the cured resin composition layer, and at least on both surface sides of the cured resin composition layer, A glass fiber fabric is arranged,
The total light transmittance of the transparent noncombustible sheet is 80% or more,
The transparent incombustible sheet whose haze of the said transparent incombustible sheet is 30% or less.   The transparent noncombustible sheet according to claim 1, wherein the curable resin includes at least one selected from the group consisting of a vinyl ester resin, an unsaturated polyester resin, and a fluorene acrylate resin.   The transparent incombustible sheet according to claim 1 or 2, wherein the resin composition contains 40 to 80% by mass of the curable resin.   The transparent incombustible sheet according to any one of claims 1 to 3, wherein the resin composition contains a styrene monomer.   The transparent noncombustible sheet according to claim 4, wherein the resin composition contains 60 to 80% by mass of the curable resin and 10 to 40% by mass of the styrene monomer.   The transparent incombustible sheet according to claim 1, wherein the resin composition is photocurable.   In the said transparent noncombustible sheet, the total ratio of the said glass fiber fabric in the total amount of the said glass fiber fabric and the said cured resin composition layer is 20-50 mass% in any one of Claims 1-6. The transparent noncombustible sheet as described.   The transparent noncombustible sheet according to any one of claims 1 to 7, further comprising a film layer on the cured resin composition layer.   The transparent noncombustible sheet according to claim 8, further comprising a network layer composed of a glass fiber network between the cured resin composition layer and the film layer.   The transparent noncombustible sheet according to any one of claims 1 to 9, wherein the thickness is 40 to 400 µm.   A smoke barrier wall comprising the transparent incombustible sheet according to claim 1.   A smoke-proof shutter comprising the transparent incombustible sheet according to claim 1.   A partition wall provided with the transparent incombustible sheet according to claim 1.   A smoke-proof curtain provided with the transparent noncombustible sheet according to claim 1.   A touch panel provided with the transparent noncombustible sheet according to claim 1.